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THE JOURNAL

Microscopical Club,

EDITED BY

EDWARD MILLES NELSON.

SECOND SERIES.

VOLUME Y.

MARINE
B^OLCGiCAL
LABCRATCaY

180S-1894

LIBRARY I

WCQDS HOLE MASS.
v. H. C I.

[Published for the Club]
WILLIAMS AND NOROATE,
14, Henrietta Street, Covent Garden, London,
AND 20, South Frederick Street, Edinburgh,

t' c (.11 r s :
South Counties Pkkss Limited

THE JOTJENAL

OF THE

^ntlutt Ulia'osfopical Club.

Striped Muscle Fibre of Pig.
By E. M. Nelsox, F.R.M.S.
Plate II, fig. 5.
(Taken as read, Novemler 20th, 1S91.J

When micro-^copists became possessed of a new and more
powerful eye by the advent of apoehromatics, among other
things, I examined striped muscle fibre, and immediately saw
several new stripes in the darker portion which lies between
the well-known stripes of Huxley and Busk, or Kj.'ause's mem-
brane. These were described by me at the R.M.S., Xovember,
1887. Since that time my previous records have been confirmed
by examination with monochromatic light, and the fibre has also
been successfully photographed; the excellent drawing from
which the figure was engraved was kindly made by Mr. G. C.
Karop, from one of the photographs.

First, my opinion is that, if anything is to be done towards
the elucidation of minute histological structures, we must
attack them precisely as if they were diatoms > There should
not be such a thing as one way of examining a histological
specimen, and another way of examining a diatom ; but there
is a right and a wrong way of using the microscope, and the
right way is the diatom method, and is the one which should
be employed on histological tissues.

I would, therefore, most earnestly enjoin all microscopists
who wish to explore more minute and still unknown regions of
histology, to pay not the slightest heed to Abbe's paper on the
wide-angled cone of illumination, but to work away at even
difficult and most unpromising structures with the wide-angled
cone. What more unpromising structure could you have than
that under present discussion, viz., an exquisitely thin and very
transparent substance in a fluid of nearly its own refi^active
index ? It should also be remembered that, after a battle of

JouRN. Q. M. C, Series II., No. 31. 1

2 E. M. NELSON ON STRIPED MUSCLE FIBEE OF PIG.

fifteen years, the truth, of the perforated diatom structure, as
seen under a wide-angled cone, has been conclusively proved, in
spite of the most emphatic utterances about the impossibilities
of doing so ; what has been done with diatoms may be done
with histological tissues.

In the first place, the minuteness of an ultimate fibril is
not sufficiently recognized. The following measures compare
favourably with those in my former paper, which were not
those of the same specimen, and which were not measured
photographically.

The single fibril here is yj^oir ii^ch in diameter; its thick-
ness is probably ^^ „ l^^J^^ inch (estimated, not measured), and
the distance from one membrane of Krause to the next is barely
tttAtto i^icli. This small portion contains no less thau eight
stripes. Their order is as follows : —

1st. The very dark and conspicuous membrane of Krause.

2nd. A very bright stripe.
, 3rd. A faint dark stripe.

4th. A light stripe, not nearly as bright as No. 2.

5th. A dark stripe, darker than N^o. 3, but not as dark as
No. 1.

6th. A light stripe, similar to No. 4.

7th. A dark stripe, similar to No. 3.

8th. A very bright stripe, similar to No. 2.

After this we come again to the dark membrane of Krause.
Each band, therefore, may be said to be about )^ ,, I ^^ ^^ inch in
diameter — this, of course, supposing them to be all equal.

In the early days of microscopy nothing but the coarse,
alternating white and dark bands were seen ; and it is to these
coarse bands that " striped muscular fibre " owes its name.
What is now called Krause's membrane, viz., the conspicuous
dark line traversing the white band, has been known for long.
It is figured in a plate dated 1852 ; there is no doubt it
could have been easily seen with objectives constructed after,
say, 1841. The next we have is an alleged bright stripe divid-
ing the large dark portion between the Krause membranes into
two equal parts. This, which is called Hensen's stripe, has been
frequently the subject of controversy, some saying that it is an
optical ghost. If you will look at the figure you will see no
white stripe, but in place of it a very narrow dark stripe, with
a white one on either side of it. You will notice that, in my

B. M. NELSON ON STRIPED MUSCLE FIBRE OF PIG. 3

former paper, it is stated tliat I had seen two white stripes, one
on either side of a known dark stripe ; but now we have
a dark stripe in the middle of a known white one. The
explanation of this is that the previously known stripe was
an optical ghost, which became white or black according to
focas, due to the customary small cone of illumination. There-
fore, if it is called black, my discovery consists of two white
stripes; and if it is called white, then mine is a black stripe.
What I claim is that, instead of one stripe, be it black or white,
there are three, in the order of white, black, white.

The most important point in the photograph which has been
faithfully represented by Mr. Karop is in the last dark space
but one from the bottom. Here the new dark stripe jDrotrudes
beyond the edge of the fibrilla. This affords a conclusive proof
that this stripe is an entity. In my anxiety to secure this
detail another is sacrificed. A drawing which combines the
points gathered from several photographs would probably
explain the subject more clearly, but as these points have been
so much controverted, it is perhaps better to keep to the
one negative. In some of the photographs a longitudinal white
stripe is seen, which apparently divides the fibrilla into two
portions. It is this longitudinal white stripe which gives that
beaded appearance which has been often noticed. It will be
observed that it is the white portions which are the weaker,
the fracture always occurring there. On the left-hand side
there are no less than three fractures taking place at the trans-
verse bright white stripes and one at the longitudinal. It
would seem that what we have called an ultimate fibrilla of
TTWWo i^ich in diameter is almost ready to break into two
fibrin ae, each being •28^(nr ii^ch in diameter.

The longitudinal white stripe is not so strongly marked
where it crosses the Krause membrane, and it is very likely
owing to that fact that the fibrilla has not split up. The
above structures, in comparison to those of diatoms, are coarse,
and of their being entities there cannot be the slightest doubt.
With regard to the physiological theory of the action of muscle
I^ have no knowledge, but it is evident that theory must
square with the structure of muscle as we find it, and not,
as is often the case, the structure made to square with an a
priori theory. The magnification is 1,750 diameters.

On Mounting " Selected " Diatoms on Slip.
By H. Morland.

{Read December ISth, 1891.)

In a paper on mounting the Diatomaceae whicli I read before
the Members of this Clnb some three years ago, I there stated
that it was my practice to mount "selected" diatoms on the
underside of cover-glass, and that far too often I found the gum
by which the diatoms were fixed showing up in a most objec-
tionable and unpleasant manner when the mount came to be
viewed under the microscope. So long as diatoms are fixed on
the underside of cover- glass I see no way of avoiding this
mishap with any degree of certainty, particularly if the diatoms
be mounted with the outer surface next to the gum or other
fixing cement.

In the old days of high power " dry " objectives it was a
matter of absolute necessity to have the diatoms close to the
cover by reason of the extremely short working focus of these
objectives, but now that homogeneous immersion lenses are
almost universally employed for the higher powers, and as
these lenses have a considerably greater working distance, this
absolute necessity of the diatoms being in actual contact with
the cover-glass may be said to no longer exist, at least, not in
999 cases out of a thousand ; all that is necessary is to have the
diatom well within the focus of the objectives.

Messrs. Zeiss and Co. in their pamphlet, when introducing
the apochromatic lenses to the public, claimed that their highest
power lens with their highest IS'.A. (viz., the lens of 2 m.m. and
1*40 N.A.) will work through a cover-glass of '25 m.ni. (or y^
of an inch) thickness. By far the larger proportion of homo-
geneous lenses have ample working distance, and so long as I
have -pJ-jY of an inch at my disjDOsal I have sufiicient room, and
to spare, in which to mount my diatoms direct on to the slip
instead of on to the cover.

The advantage of mounting on the slip is that as most

H. MORLAND ON MOUNTING SELECTED DIATOMS. 6

diatom-valves are hollowed out with an edge on a flat plane,
these valves can be fastened down with the hollow side next the
slip, merely resting on the thin outer edge, and with their
outer surfaces uppermost and nearest the observer. This
obviates all clogging of fine structure by the gum, and though
air may be boxed in under the valve, yet as the structure of the
diatom-valve is generally cellular and permeable by the balsam,
this latter is almost always able to displace the imprisoned air
under the valve. Another advantage is that when a valve
happens to be very convex it is an exceedingly difficult affair to
mount such a valve squarely if resting on the convex side ;
moreover, as a rule, the outer surface of a diatom is far more
interesting to observe than an inner surface, which in many
forms consists simply of " eye-spots."

The diatoms having been mounted on the slip, it is necessary
to so arrange that the cover-glass shall be brought down suffi-
ciently low as to bring the upper surface of same well within
the working distance of the objective. This I manage, firstly,
by having cover glasses not exceeding "OOo" in thickness ; and,
secondly, by gumming three small metal discs, '003" thick, in a
triangle round the "selected" diatoms, each side of the triangle
being about y^ of an inch. When the balsam is applied and
the cover-glass put on over same, and pressed down close to the
metal discs, it follows as a matter of simple addition that the
upper surface of the cover-glass is only -008" from the upper
surface of the slip, so that with an objective of '01" working
distance, the observer would be able to not only focus every
part of the diatom, but even beyond into the slip itself.

So far as regards these metal discs, I may add that they are
of about ^^ inch in diameter, and in the first instance I pre-
pared them from some thin copper garden labels (Chandler's
patent), of which I had purchased a half -gross for trial in my
garden. Noticing that these 72 labels, when placed one above
the other, were less than ^ inch in height, it struck me that I
had here a material sufficiently thin to place between a slip and
cover, giving ample room for diatoms lying flat, and yet allow-
ing an objective of not more than y^ inch working distance to
focus down into the slip itself. My die is simply a piece of
cast steel, as shown in Figs. 1 and 2, 1| inches long, | inch
deep, and f inch thick, with a -^^ inch hole drilled through the

b H. MORLAND ON MOUNTING SELECTED DIATOMS.

depth -j^ inch from either end, the die being afterwards sawn
from the ends a little beyond the drilled holes. A hole is
drilled through the centre of the die, by which the same can
be fastened down on a board or table as may be desired.
The die must, of course, be finished off by being duly hardened
and tempered. The punch consists of a piece of steel drill-
rod (Fig. 3) accurately fitting the small hole, with one end
filed off perfectly square, and the other end provided with a
brass or copper head driven on for receiving the blows when in
use.

I may say that the die as shown is doubly reversible, viz., end
for end and top for bottom. To use the die and punch, enter
the latter in one of the holes as far as the upper edge of lower
saw-cut, and, after placing the thiii copper in the saw-cut, tap
the punch lightly with a very small hammer, when a small
copper disc will be pushed out below. After a supply of discs
has been punched out they will require flattening as they leave
the die slightly cupped, which adds to their height. To flatten
them I simply place a dozen or so on a thick glass slip, and
with another thick slip press them flat. It is as well to boil
the discs in soda to free them from any grease, and then to
pickle them a short time in aqua fortis, finally washing them
well in several changes of boiling water to get rid of all traces
of acid, drying off in a hot oven and corking them in a dry
specimen tube to preserve them from damp, which otherwise
would cause these copper discs to slightly oxidize and tinge the
balsam green when in use.

H. MOELAND ON MOUNTING SELECTED DIATOMS. /

I have lately been turning my attention to tlie employment
of thin aluminium in lieu of copper as being free from the risk
of tingeing the balsam through becoming oxidized. I find that,
this metal can be obtained rolled in thin strips about three
inches wide, toVu i^i^h in thickness and upwards. This metal
as purchased is hard and elastic, and therefore requires to be
annealed, as otherwise it would be difficult to properly flatten
the cupped discs after they leave the die. I find it can be
annealed and rendered very similar to thin copper to the touch
by simply moving the thin metal to and fro in the flame of a
spirit lamp, taking care not to burn the metal by overheating.
It will be known when this process is complete by the behaviour
of the aluminium when handled by being passed between the
fingers. For general use I consider that discs of from '002" to
•003" are amply thin enough, but I have prepared some as thin
as Y2V0" ^^^^ ^^ thickness. These latter, however, I could only
use in very exceptional cases.

In lieu of metal discs thin glass squares can be employed, but
it is difficult to obtain sufficiently thin glass. To cut very small
squares, viz., of -^^ inch, or even as small as ^Jy inch, fasten a
piece of thin glass on a square piece of brass by means of tallow ;
then, if this piece of brass be fixed just below the surface of a
planed board, the glass can be cut up as desired by means of a
writing diamond and a marquois scale and square. Remove
the cut-up glass by heat, and boil the small glass squares in
soda and water to get rid of the tallow.

As the surface of glass slips is very often far from being all
that could be desired, it is as well sometimes to first mount a
cover on the slip, and arrange and fix the diatoms on the upper
surface of this cover-glass, finishing up with a smaller cover.

It must by no means be supposed that I have given up
mounting on the underside of cover- glass. 'I still continue to
do so in the majority of cases, only adopting the method now
described when thought advisable.

A Simple Method of Finding the Refractive Index of
Various Mounting Media.

. By E. M. Nelson, F.R.M.S.

(Taken as read, January 15fh, 1892.)

Provide two precisely similar equi-convex lenses, -wliose
identical refractive index, /x, and radii, r, are known, and
cement them together with the mounting medium whose
refractive index has to be determined. Now measure F, the
principal focus of the combination, then the refractive index of
the mounting medium.

^ ^ 2F

It is convenient to make the radii of the equi-convex lenses
two inches. Then —

^, = 2^-1-1

Some examples might be of interest.

Let the refractive index /x of the two equi-convex lenses be
f, and suppose that the combination has no focus, that is, that

it behaves like a piece of plane glass, then F = oo,— = 0, and
/x'== 2/A— 1 = 2-0.

If the principal focus of the combination F = -f 2 then

/x.' = 2 ju. — 1^ := _ or the same as that of the equi-convex
lenses.

But if the principal focus of the combination F is negative,
it must be measured in the same way as a concave spectacle
lens, viz., by neutralizing it by a positive lens of equal focus.

If F is negative the sign before the fraction will be changed.
Example, let F = — 2. Then —

/.' = 2/.-l— _i = 2yu~l-fi = 2-5.

The above method gives a greater range of readings for
indices varying from 2*0 to 2'5, and consequently more accurate
results than the simpler one of filling up a plano-concave lens

E. M. NELSON ON FINDING REFRACTIVE INDEX OF MOUNTING MEDIA. 9

with the medium, and covering it with a piece of plane glass.
The formula for this latter plan being fx' =z fj, -[- ^ The radius
of the concave r might with advantage be made two inches,

F = CO , / = I ; if F = 4, nx' = 2-0 ; and if

ti

len

/*'

/*

+ !■

If

H--

=

*,

and

F

=

2,

/-'

:2'5.

10

Note on a Species of Ixodes found upon a South African

Lizard.

By R. T. Lewis, F.R.M.S.

Plate I.

{Read January 15th, J892.)

During the past year I liave on several occasions received
from a correspondent in Natal specimens of ticks, to which
special attention was drawn on account of the serious injury
inflicted by them upon domestic animals, especially horses and
cattle. On mentioning the subject to a friend, who had been
for some years resident on an ostrich farm in the colony, I was
assured that the family was so well represented there that
nothing seemed to escape them; that they varied in size from
scarcely visible specks to about fin. in length, and that birds,
beasts, reptiles, and human beings were alike the objects of
their unpleasant attentions.

My friend went on to describe the nature of the bites inflicted,
the after consequences of which were always seriously aggra-
vated by too hasty attempts to forcibly remove the creatures ;
such being the tenacity of their hold that they usually suffered
the body to be dragged from the head rather than let go, and
the rostrum being thus left imbedded in the flesh gave rise to
inflammatory swellings known as Natal boils, which became
more or less troublesome according to the season and state of
health of the persons bitten. Most of the species sent appear
to be such as are only too well-known as cattle pests ; but last
month I received three samples of a kind which proved to be
more rare, for although there are several specimens in the col-
lection at the British Museum, they are at present unnamed,
and, being presumably undescribed, may therefore be made the
subject of a note of some possible interest to the members of
the Club. They were found upon a species of Iguana which
lives in the marshes, but is said to be unlike the American form

R. T. LEWIS ON A SPECIES OF IXODES. 11

in having a comparatively small and short body and a very long,
thin tail, which it switches about like a whiplash. So far as
can be judged by the description given and a portion of the skin
sent, this reptile is probabl}'' a Varanus, several species of which
are known to inhabit the district, and as the ticks in question
are usually found grouped together under the lizard's tail, the
irritable movements already alluded to would seem to be thus
abundantly accounted for.

Attempts to dislodge these ticks uninjured proving fruitless,
a portion of the skin to which three were adherent was sent to
me by post ; on arrival I found them dead and perfectly dry,
but with some trouble and much care I succeeded in detaching
them, and in two cases without injury to the mouth organs.
As regards size, each specimen measures 2'4 m.m., or one-tenth
of an inch in breadth, with a length, exclusive of the rostrum,
of 2'6 m.m. The dorsal surface (Plate I, fig. 1) is, in colour, a
rich purple brown, with nine sharply-defined, irregularly-shaped
patches of a bright yellow tint, the whole being pitted with
numerous dark spots, which have the appearance of being the
remains of follicles, from which at one time hairs arose ; in tex-
ture it is hard and unyielding, preserving its natural shape and
contour in the desiccated condition. The ventral surface, on
the contrary, is, during life, soft, elastic, and pleated into many
folds, so as to admit of considerable augmentation in the size of
the abdomen when gorged with alimentary matter.

The eight legs have seven joints each, of which the coxa is
armed with a hard spinous process, and the terminal joint of
the tarsus is furnished with two claws and a number of hairs,
two of which are of considerable length. On the median line,
near to the posterior end, there is a well-marked anal orifice,
but the position of the ovipositor is only made out with diffi-
culty between the basal joints of the second pair of legs. The
external organs of respiration are two very clearly-defined stig-
matic plates of oval shape a little Within the marginal line, a
short distance to the rear of the fourth pair of legs. The
general colour of the ventral surface is dark chrome yellow,
with the legs a russet brown. The greatest interest, however,
naturally attaches to the mouth organs, which, when examined
under the microscope, are seen to comprise means of offence of
a very formidable kind ; but an accurate and exhaustive de-

12 R. T. LEWIS ON A SPECIES OF IXODES.

scription of them is unfortunately beset with difficulties, re-
quiring, as it would for its completion, the examination of many-
specimens, living as well as dead, together with dissections and
preparations, for which the present supply is entirely inade-
quate ; added to this, each independent writer upon the subject
seems to have adopted a different view as to the homologies of
the parts, resulting in many synonyms and a confusion of nomen-
clature, which, to say the least, is a little bewildering.

The most, therefore, that I can hope to do on this occasion is
to describe the appearance presented by such portions as are
visible in the dried specimens, which at least have the advan-
tage of being unaltered in shape or relative position by any
processes of preparation or pressure in mounting.

I am, however, much indebted to my friend, Mr. Thomas
Curties, for kindly placing at my disposal for purposes of com-
parison some excellent slides of various ticks, which have been
of material assistance in tracing their analogies. The rostrum,
as seen in profile (Fig. 2), consists mainly of two parts, separ-
able from each other, but with their adjacent surfaces so true
as to admit of the closest contact between their outer edges.
Of these the lower, or ventral portion, is commonly termed
the labium. The upper portion, which is slightly longer than
the labium, is bevelled off downwards near to the apex, from
which the ends of two pairs of cutting instruments are seen to
project. Viewed from above (Fig. 3), it gives the impression
of being formed of two parallel tubes, '55 m.m. in length, with
a combined breadth of "2 m.m., laid side by side, and fused
together along the line of contact ; certain it is that they are
tubular throughout, and that one purpose which they serve is
that of a protecting sheath to the cutting tools or mandibles
within. Specimens of allied species, prepared so as to be almost
translucent, and mounted in balsam, show the mandibles
passing freely through, and enable them to be clearly traced
backwards to their muscular attachments behind the head. A
well-marked median suture suggests the idea that these sheaths
were at one time separate ; but experiment shows them to be so
no longer, although they have in one or two mounted specimens
become so, as the result of maceration and flattening under pres-
sure.

"When looked at "-end on " (Fig. 5), or in transverse section,

R. T. LEWIS ON A SPECIES OF IXODES. 13

it is seen that tlie line of fusion is not equally well marked above
and below, but that whereas a slight groove only remains upon
the upper surface, there is one of considerably greater depth
and breadth below. A pair of palpi arise from the ventral sur-
face of the head adjacent to the base of the labium ; these are
four-jointed, the second joint being considerably longer than the
others, and the fourth (scarcely discernible in a dried specimen)
is furnished with a circular tuft of apparently sensory hairs.

One of the characters of the genus Ixodes, given by Van der
Hoeven and others, is " palpi sheathing the rostrum," which
these can scarcely be said to do, although in a large specimen
of cattle tick, still alive in my possession, I notice that these
palpi are, when at rest, brought up close to the sheath, and that
the terminal joints are bent towards each other as if to afford
additional protection to the apices of the mandibles. In every
species yet examined the whole rostrum is capable of being
moved through an angle of at least 90° from the horizontal
downwards by the elevation or depression of the head. It will
be seen from Fig, 4 that the labium, as viewed from its under
side, contracts in breadth from its base for about half its length,
thence expanding again, but at the same time diminishing in
thickness so as to resemble in shape the convex side of the
bowl of an ordinary bone egg-spoon. The part nearest to the
base is ribbed, and has the appearance of possessing great
rigidity and strength, whilst the spoon-shaped portion is set
with six rows of triangular barbs, seven in each row, and all
pointing downwards and backw^ards, at an angle of about 35°.

The structure of the lacinia — or mandibles, as most authorities
term them — is not so easily made out ; but repeated examina-
tions of each available specimen in many different ways, and a
comparison with an allied form found upon a tortoise, lead to
the conclusion that there are two pairs, which differ in shape,
and are capable of independent movement within a radius at
least equal to the semi- diameter of the rostrum. The outer pair
(Fig. 7) are nearly flat, the apex being smooth at the back, but
furnished on the opposite margin with three lancet-shaped
teeth, pointing outwards, and apparently sharp on both edges,
so as to cut equally well with a backward or forward thrust.
The inner pair (Fig. 6) are more peculiar in shape, the shaft
being deeply hollowed like the blade of a gouge, expanding to-

14 R. T. LEWIS ON A SPECIES OF IXODES.

wards the apex, and terminating witli a curved spear-shaped
tooth, flanked at a short distance helow by two others, the
points of which are very fine and slightly recurved. These
denticulations, like the others, also point outwards, and when
withdrawn within the sheath the flat back of the first blade lies
within the hollow of the second for mutual protection and
economy of space (Fig. 8).

The structure of the entire arrangement suggests the modus
operandi to be as follows : An incision made in the epidermis by
the first pair of mandibles is enlarged and cleared by the scoop-
like blades of the second pair, the tapering end of the rostrum
being inserted and continually pushed forward into the orifice
until the blood-vessels are reached, and in like manner cut
through. By the muscular expansion of the abdomen (?) the
blood is then freely drawn up the suctorial tube, formed by the
groove between the labium and the under surface of the sheath.
The resistance offered to any forcible withdrawal by the holding
power of the forty-two barbs on the labium is sufficiently
obvious, and, apart from such inflammatory action as might
arise from the labium being broken off and left embedded in the
flesh, it seems clear that in any case a wound so produced would
be a source of more lasting annoyance than the more cleanly
cut incision of the familiar flea.

Although I have not been able to find this species figured in
either of the illustrated works consulted, it would be rash to
assume at present that it has not hitherto been either named or
described. Otherwise I should venture to propose that it be
called Ixodes varani, as indicating the source of supply.

Explanation of Plate I.

Fig. 1. — Dorsal view of tick, x 20

„ la. — „ „ natural size

„ 2. — Rostrum — lateral view, x 45.

„ 3.— „ —dorsal „

„ 4.— „ —ventral „

„ 5. — „ —end „ „

„ 6. — Inner mandible — right side, dorsal aspect.

„ 7.— Outer „ „ „

„ 8. — 6 X 7 shown in situ.

16

On the Macrotrachelous Callidinj:.

By David Brtce.

{:Read l5th January, 1892.)

Plate II.

I propose to put before you this evening a few remarks upon
certain Bdelloid Rotifers, which I term the Macrotrachelous
Gallidince, and to conclude with brief descriptions of four new
species.

The genus Callidina comprises, as is well known, those
Rotifers of the Fhilodinadoe which possess no eyes, and is
represented in the great Rotifer text-book by 10 admitted
species, while seven others are referred to as doubtful or
imperfectly described forms. For three of these last I claim
readmission. The Callidina constricta of Dujardin is perhaps
not satisfactorily described by the French Naturalist, but Mr.
Milne has published a very thorough description of a form
which he identifies with it, and he states expressly that
Dujardin's figure is a very successful one. Indeed, if the
species be not admitted on the original description, it must be
on that of Milne, and so, too, must C. musculosa, as both species
are of frequent occurrence, and easily identified from the
characters given. As to the third form, Callidina tridens, I
have not yet succeeded in identifying it, but I am not disposed
on that account to consider doubtful a species so fully described
by an observer who has given special attention to the genus.
One other species of Mr. Milne's, C. reclusa, was described too
late to be mentioned in the Supplement. These bring the total
up to 14 species, and a fifteenth was recently brought before
you by Mr. Parsons. If you further add the four species which
I shall presently introduce to you, and still two others which
will shortly be described by Mr. Percy Thompson, you will find
that the humble and usually overlooked genus Callidina numbers
no less than 21 species, of which at least 19 occur in this
country. It has thus a certain numerical importance, but I

16 D. BRYCE ON THE MACROTRACHELOUS CALLIDINJ).

desire to show you that it is important from a higher point of
view, viz., that the habits and life histories of various species
present to us some very interesting biological studies, peculiar
so far as is yet known to this one genus.

But which are the Macrotrachelous CalUdince ? On page 59
of the Supplement Dr. Hudson tells us that Milne proposes
the genus Macrotrachela for three-toed PMlodinadcB, having the
pre-intestinal part of the body decidedly longer than the post-
anal, and that all the species are Callidmce. When this was
written Dr. Hudson had probably not seen Mr. Milne's second
article (No. 187 of the " Bibliography "), for in it was described
a species, Macrotrachela Boejoeri, very similar in habits and
general structure to Callidina 7'eclusa, but possessing two dis-
tinct eyes within the frontal column, and, .therefore, technically
not a Callidina. In this article, and apropos of these closely
related species, Mr. Milne again urged the proposition made
originally as regards the species now known as Adineta octdata,
that Ehrenberg's classification of the FhilodinadcE was unsatis-
factory, insomuch as it associated species mani^sstly distant,
while separating species as manifestly of a close relationship.
To amend the position he proposed in his earlier paper a new
arrangement of the genera, and among other suggestions
brought forward the new genus Macrotrachela. To my mind
this genus associates a very compact group of species, with a
decided family likeness, and 1 should much like to adopt it,
and to see it accepted, but the scheme involves the primary
separation of the Fhilodinadce into those having four toes and
those having three toes, a character extremely difficult to detect,
and, therefore, a bad one for such a purpose. Without going
further into this matter, I have ventured, by the use of the
term Macrotrachelous, to avail myself of the most valuable of
Mr. Milne's suggestions, to denote those Gallidinoi in which,
Avhen fully extended, the post-anal portion is decidedly shorter
than the pre-intestinal.

Three species, jparasitica, socialis, and magnicalcarata, do not
possess this character, and these, therefore, do not fall within
my subject matter. They have, however, one common point of
interest, namely, that all three are ecto-parasitic upon other
forms of animal life.

The remaining species are all Macrotrachelous. Their great

D. BRYCE ON THE MACROTRACHELOUS CALLIDINJ:. 17

peculiarity is tliat by far the majority of them seem to have
their habitat among, or upon, the stems, leaves, or bracts of
various mosses. Specimens are rarely found in ordinary dip-
pings, nor are they met with crawling over the leaves of the
usually gathered water plants, and this is doubtless the reason
why so little has been known about them. My own method of
collection is both successful and very simple. Provided with
several wide-mouthed bottles, with tightly fitting corks, I
gather (with as little soil as possible) threads or stems of moss
from old w^alls, from damp banks, from the bark of trees, from
alongside pools, or, best of all, from tufts of Sphagnum. I take
care not to pack the moss tightly, nor do I add water, for the
moisture clinging about the moss is sufficient (in a well-corked
bottle) to keep the CallidincB alive for months, I presume in a
succession of generations. This refers to moss gathered in a
moist state, but if gathered from dry positions it may be
slightly damped, no more. The store bottles (for which may
be substituted tin canisters) should be kept in a cool room,
and exposed to nothing stronger than a north light. When
convenient I place a stem or two in a zoophyte trough, and
add water. After a few minutes I move the moss briskly to
and fro in the w^ater, and then remove it. I place the trough
in an inclined position, and when the water is sufficiently clear
I remove it to the inclined stage of my microscope. A brief
search with the one-inch powder generally reveals specimens of
several species of these CalUdince, accompanied by Adineta vaga,
and several species of the Catliypnadte.

I have not succeeded in locating any favourite lurking place
of the apparently free-living species about the moss stems, but
the forms symhiotica and Leitgehii are stated to make their home
in certain cavities and corners formed on the under side of the
leaves of four species of Jungermannit^, and Dr. Hudson, in a
very interesting passage, relates to us how, after reading Dr.
Zelinka's account of their habit of life, he remembered where
he had noticed some moss of one of these species, and having
brouo'ht some home was delighted to find some of these Callidince
inhabiting it in the manner described.* These two forms, sym-
hiotica and Leitgebii, have a special interest. They appear to

* I hiive to thank Dr. Carl Zelinka for a copy of bis instructive paper
which he most kindly forwarded to me.

JouRN. Q. M. C, Series II., No. 31. 2

18 D. BRYCE ON THE MACROTRACHELOUS CALLTDINJ:.

be constantly associated with these four species of moss, occur-
ring in specimens gathered in the most remote districts of
Germany and Austria, and at least in one case in England.
But, further, this constant association has suggested that there
is a certain benefit accruing to the moss-plants from their
affording house-room to these Callidince, and that there is here
a true case of symbiosis. We have, in other Rotifera, instances
of both the complete and the partial parasitism. To use every-
day language, some species are "full boarders," others are only
" lodgers," yet neither class gives any return for benefits
received. In Callidina symhiotica and C. Leitgebii we have, T
think, the first species of Rotifera whose association with
another organism has been supposed to be mutually advan-
tageous.

There is no suggestion of symbiosis made with respect to
Callidina reclusa, but its life-history is quite as remarkable. I
may be allowed to bracket with it for the present purpose the
species Boeperi, already mentioned, as having a similar habit of
life. These two species live in the cells forming the outer layer
of the stems of the small side shoots of Sphagnum. If you place
under your microscope such a stem from which you have
stripped the leaves you will see that this outer layer consists of
elongate cells of some little size, and that many of them possess,
usually at one extremity, an opening whose margin is some-
times rather elevated, and through which water may freely
enter into the cell cavity. These peculiar cells are found by
these Rotifers to be exceedingly convenient. There is sufficient
space inside to allow them to turn about, and there is a suitable
opening from which to protrude their heads when they are
hungry, and desire to gather food supplies by the action of their
trochal discs. They are protected both from sudden drought
and from the atta(;ks of roving enemies. They lay their eggs
in the cells, and, indeed, it is probable that under ordinary con-
ditions they rarely quit a cell in which they have once estab-
lished themselves. They are to be found in nearly every piece
of freshly gathered Sphagnum which may be examined, and I
have succeeded in keeping a colony alive in captivity for some
little time.

As far as I have yet seen, none of the other forms known to
me can be said to prefer any one kind of moss to the exclusion

D. BRYCE ON THE MACROTRACHELOUS CALLIDIN^. 19

of others, but there is doubtless much to be learned yet both
about this and the supposed symbiotic relations to which I have
referred.

The form described by Mr. Milne as the Callidina elegans of
Ehrenberg, and which I believe to be quite distinct from the
species described by Mr. Gosse under the same name, is by no
means uncommon. It usually appears in the trough as a rest-
less wanderer, and will crawl about for hours without protruding
its wheels. On one occasion I found a colony established in
one of my jars, and I discovered that it had the habit of
gathering around it, by the continued action of the wheels, a
small heap of dirty floccose matter, similar to that made by
Rotifer 7nacTOceros, but with this difference, that whereas the
latter Rotifer usually perches upon a conferva thread or in the
axil of some leaf, the Callidina appeared, in the absence of
such convenient spots, to have simply gathered its little pile
wherever it might happen to be. I found the little houses
lying free among the sediment.

Mr. Milne has recorded some similar tube-dwelling speci-
mens, but does not appear to have made out the species, and I
am in the same position with regard to another series of indi-
viduals, which were neither the above-mentioned 0. elegans nor
any other of the forms familiar to me.

I have frequently kept specimens of both constrida and
quadricornifera for many days in a trough, and have never
observed in either the least approach to this tube-making habit.
On the contrary, without being w^ild, they, and also miisculosa,
lata, and pUcata, do not care to remain long at one spot. They
readily protrude their wheels, and will continue feeding for
some time, but presently, for some apparent reason, they with-
draw their coronae and march, caterpillar fashion, a very little
way, and again commence feeding, and so on. Whether it be
that they thus endeavour to avoid the accumulation of refuse
about them, or that they find that they are attracting the same
rejected particles over and over again ; whether they are timid,
or perhaps sensitive to the unaccustomed glare of light, I
cannot say, but such is their behaviour when under observa-
tion. These five species are all moderately common and easily
studied.

There are only two species which swim readily — these are

20 D. BRYCE ON THE MACROTRACHELOUS CALLIDIN^,

musculosa and a form which I take, but with great doubt, to be
the hihamata of Gosse. Each has its own peculiar attitude and
movement.

The other species confine themselves to crawling, mostly after
the caterpillar fashion, common to the Philodinadw, yet some
with a peculiar modification of it noticed both by Gosse and
Milne. It is a peculiar mixture of gliding and creeping, and it
has been suggested to me that the usual movement of Adineta
is of the same character. The effect is indeed the same, but it
is produced by very different means. In Adineta the corona
has been modified into a mere furring of a ventrally placed por-
tion of the head, and the gliding motion is due to the action of
the cilia which form the furring of this prone face. In these
CallidincB the corona is completely retracted during the progres-
sion, and the motion is due to a number of strong cilia which
protrude from the hollow tip of the frontal column when fully
extended, as in crawling. Thus, so soon as the toes leave hold
of the glass, these cilia, by their action on the opposing sur-
face, drive the Rotifer forward until the toes can again fasten
themselves. The species in which the cilia of the column are
so powerful as to produce this gliding movement, possess therein
a method of progression distinct from that of any other Rotifers
known, in arising from the action of cilia which have no connec-
tion either with the corona or with the buccal orifice.

Another curious peculiarity of some of these forms is their
treatment of the food particles after these have passed beyond
the mastax. In constricta and some others the food is then
formed into small pellets, suggestive of those seen in Para-
mecium^ but probably moulded in an oesophagus ; and the
capacious stomach presents a very joeculiar appearance when
filled with these pellets. An alternate heaving motion provides
the necessary agitation of the food. In other species the
alimentary canal can be more readily seen to be a long tube in
which the food, not moulded into pellets, is agitated by power-
ful cilia. In some cases I have not been able to detect the
presence of cilia at all.

It would be unfitting to attempt here even a brief description
of the structure of one of these Callidvicv, but as I should wish
these notes to have more than a passing interest, I will very
shortly indicate some points to which a student should pay par-

D. BRYCE ON THE MACROTRACHELOUS CALLIDIN^. 21

ticular heed, and I can predict that he will be astonished at the
well-marked individualities which he will find to exist.

Commencing with the trochal discs, he should note their
breadth, relative distance, height from secondary wreath, and
^iroportion to breadth of head ; the positions in swimming, feed-
ing, crawling, partial retraction, and complete retraction ; the
shape of the rami, and the number of teeth on each, taking care
that he does not mistake fine teeth for the fine striae frequently
present ; the structure of the frontal column and the membran-
ous shielding flap with which the tip is provided, and which
might be mistaken for two hooks ; the antenna, its length and
direction ; the skin, its folds, surface, and pseudo-armature.
The foot should be considered as including only the post-anal
segments. The spurs, though usually short, are very distinctive,
and the toes very difficult to see at all, far less define and count.
The treatment of the food and the various movements assist-
ing the digestive action should be watched while the animal is
feeding. Above all, sketches should be made and copious notes
taken at every opportunity.

Before mentioning the characters of the four new species I
wish to say that I have not been able to identify, to my own
satisfaction, any of the Gallidince described by Mr. Gosse, and
that if anyone here can furnish me either with specimens or
with further particulars of these species he will confer upon
me a very great favour.

Gallidina plicata, n. sp.

Sp. Ch. — Elongate and without medial swelling when crawl-
ing. Central portion of trunk with coarse dorsal and lateral
skinfolds, mostly extending forward over anterior portion and
the central dorsal pair extending over posterior segment, the
latter, conspicuously swollen and hood-like, constricted at upper
and near lower end. Foot only displayed when crawling.
Spurs moderately stout and short cones, with slightly produced
points, showing (rarely) narroAv interstice when at greatest
separation. Wheels rather large ; mastax ample, rondo ovate,
two teeth on each ramus.

Intestinal action a periodic heaving, food not moulded into
pellets.

It is possible that the hood-like segment, apparently consist-

22 D. BRYCE OS THE MACROTRACHELOUS CALLIDINiE.

ing of one joint, is, in reality, a modificaMon of the two ultimate
trunk joints.

Length — Extended about J-^ inch.

Habitat — Among Sphagnum and other mosses. Epping Forest
and Isle of Wight. Common.

Gallidina lata, n. sp.

Sp. Gh. — Very short and broad, central portion of trunk much
flattened, broadest behind the middle, suddenly narrowing to
posterior segment. Dorsal skinfolds obsolete, lateral very deep.
When feeding posterior trunk segment about one-third width
of central portion. Foot slender, spurs slender, acute and of
moderate length without interstice. Wheels rather small, about
width of head. Food moulded into coarse pellets. Mastax
pyriform, three teeth on each ramus. Column furnished with
rather long cilia.

The peculiar breadth and squareness of the central portion
of the trunk is usually apparent even in crawling. Occasionally,
however, a specimen will present, for a moment, the facies of a
,Philodina. Incomplete retraction it assumes the form of a
broad ellipse whose greatest length is transverse to the body
axis. A rather small form, yet varying much in size, large
specimens about ^ ^-^ inch when extended. It crawls rather
slowly, yet with a slight gliding motion as described above.
I have thought that I could detect a few setae at tip of column
as well as the usual cilia.

Habitat — Among Sphagnum and other mosses. Epping Forest?
Folkestone, and Isle of Wight. Scarcely so common as the
last.

Gallidina spinosa, n. sp.

Sp. Gh. — Longitudinal skinfolds and those marking trunk
segments armed with very short prickle-like points set closely
together, the angles marked with rather longer points. A
short spine on centre of ventral margin and a longer one at
each lateral angle of anterior edge of first trunk segment.
Spurs rather long and of peculiar shape, at first parallel,
they are bent outwards at a right angle and thence incurved,
so that each describes a J circle, the points being directed
downwards and backwards.

I only found one specimen of this peculiar form ; it was ex-

D. BRYCE ON THE MACROTKACHELOUS CALLIDIN^. 23

ceedingly timid and would scarcely extend itself, far less com-
mence feeding. The cuticle was dense, and I could not get at
internal details, nor could I count with certainty the number of
teeth on each ramus. When extended it had rather the outline
of a Philodiiia, but I could not detect any eyes. As the head
and neck were protruded the lateral s^Dines became depressed,
falling close to the sides. The spurs have a distinct re-
semblance to the toes of TapJirocampa selemcra, and were each
nearly i-^q^ of an inch in length, that of the whole animal ex-
tended beinoc estimated at about -^— of an inch.

o 14

Habitat — Among Sphagnum from Sandown, Isle of Wight.

Gallidina aspera, n. sp.

Sp. Gh. — Longitudinal folds of trunk, both dorsal and ventral,
beset with closely set blunt points. Mastax rondo-ovate with
two teeth on each ramus. Spurs small cones, just longer than
thickness at base. Of a brownish colour. Wheels rather
small, scarcely wider than head.

Several specimens found among Hypnum given to me by Mr.
ThomjDSon, and gathered by him in Epping Forest.

Length about -pi-g inch extended.

Habitat — As above.

Description of Plate II.

Fig. 1. — Gallidina plicata, wheels protruded, dorsal view.

la. Foot extended as in crawling, lateral view.

16. Ditto, ditto, dorsal view.
„ 2. — Gallidina lata, wheels protruded, dorsal view.
„ 3. — Gallidina spinosa, retracted, ventral view. 3a.

Spurs.
„ 4. — Gallidina aspera, wheels protruded, dorsal view.

24

Chantransia trifila : A New Marine Alga.
By T. H. Buffham, A.L.S.

(Read Feb. 19, JS92.J

Plate III.

The genus Chantransia includes some species which li-ve only
in fresh water, while others are found in the sea. Those
marine species known in Harvey's time as British were in the
Phycologia Britamiica included by him in Gallithamnion as he
considered they bore tetraspores. This, however, is now
known to have been a mistaken observation, as their neutral
organs are undivided, i.e., they are monospores. Until recently
the antheridia and cystocarps were known in only two species,
one fresh water : Ch. investiens Lenorm. ; the other marine :
Ch. corymhifera Thur. Mr. G. Murray, F.L.S., and Miss Ethel
S. Barton have, however, described and figured all three kinds
of reproductive organs in a new British fresh watei' species —
Gh. Boweri discovered by Mr. Murray and Prof. Bower in Scot-
land in April, 1890. For a full account of this species and of
the present position of this genus, which has had a remarkable
history, the student should refer to the paper by the authors
just named (" On the Structure and Systematic Position of
Chantransia'' in Jour. Linnean Soc, Vol. xxviii, p. 209). I
need only remind you that all the marine species are epiphytic
minute, generally even microscopic ; while the sexual organs
are of the simplest character known in the Florideoi.

The plant I have to describe was found (Aug. 1890) epiphy-
tic on an old j)iece of Gladophora (? utriculosa Kiitz.) which,
fortunately for the study of the Ghantra7isia, had discharged
nearly all its green contents in the form of zoospores. As
there were several hundreds of specimens of the Chantransia
there was ample material for learning the true characters of
the epiphyte in all stages of the neutral or monosporiferous
state, there being no sexual organs found.

T. H. BUFFHAM ON CHANTRANSIA TRIFILA. 25

I regard the mature plant as that condition in which mono-
sporangia are borne, for within very narrow limits the fertile
plants may be described as almost precisely alike. When in
this condition the plant starts with a basal cell, undivided, by
which it is attached to the host plant. This cell is nearly
spherical, oblate, about 6 /a in horizontal, and 5 /x in vertical,
diameter. From it arise three filaments : the right and left
ones slightly incurved, each consisting of three or four cells, all
but the apical one being about 5 or 6 /i long, and nearly as
thick, but the apical cell is frequently conical, 3'5 /x thick at
base, and prolonged into an excessively fine hair, at times as
long as the four-celled principal filament itself. Between the
lateral filaments arises vertically the third filament, of nearly
similar character and dimensions, so that all three filaments lie
in the same plane. The monosporangia are terminal on one- or
two-celled branches, generally on the inner side of the lateral
filaments. These branches are as a rule parallel with the
middle vertical filament. The monospore is spherical, 7-8 /a
diam., and is discharged from the sporangium at its apex.
There are rarely more than two on a plant at the same time.
The middle filament is seldom branched, and its branches
rarely fertile. I have observed no clear case of a fertile plant
without these three primary filaments, and I have never
observed more than three. The vertical height of the mature
plant — not including the terminal hairs— is 27-30 /x (•0011-12
inch). Thus it must be the smallest Floridean known, and a
Microscopical Club is appropriate for its first introduction.

When the monospore is discharged its contents contract and
become darker, and its lower side, in contact with the host,
hyaline. A lateral cell buds out on one side, and grows into
an inclined filament of two or three cells before the correspond-
ing one appears to match it on the other side. These attain
nearly their full length before the middle one begins to appear.
Then a branch or two arise to bear th,e monosporangia. I am
not aware of any parallel case where a single basal cell gives
origin to three primary filaments.

The characters of this curious little plant may be summarised
thus : —

Gliantransia trifila n. sp. — Very minute, about 27-30 /w, high.
Basal cell single, being a modified monospore. From this arise

26 T. H. BUFFHAM ON CHANTRANSIA- TRIFILA.

three filaments in one plane, of three or four cells in length,
sometimes terminating in a very thin hair. Cells about 5 fx
long, and 4-5 /a diam. Monosporangia 7-8 ft diam., spherical,
terminal on 1-2-celled branches on the inner sides of lateral
primary filaments. Antheridia and cystocarps unknown.
Habitat. On old Cladophora (? utriculosa Kiitz.), Swanage.

Explanation of Plate III.

Ghantransia trifila n. sp.

Fig. 1. — A fully mature plant with three monosporangia,
one of which is empty. X 200.
,, 2. — Mature plant with two monosporangia. x 1000.
„ 3. — Empty monosporangium. x 1000.
,, 4. — Very early stage : the basal cell and one lateral
filament of three cells, x 1000.

27

Conjugation of Diatom: Orthoneis binotata Grunow.

By T. H. Buffham, A.L.S.

(Read Feb, 19, 1892.J

Plate III.

The valve of this marine diatom is elliptical, axes of the
ellipse as 4 : 3, with a median raplie, central and terminal
nodules, and a more or less indistinct stanros. The transverse
rows of dots are straight near the centre of the valve, and
curved as they approach the extremities, about 40 in '001 inch
(=16 in -01 mm.). These cover the whole of the outer surface
of the valve. Viewed from the inner side there is seen to
project from each lateral edge of the valve a semi-elliptical
plate which reaches about half way towards the raphe. The
plate has a length of about half that of the valve, and one-
fourth that of its breadth. Although a prominent feature in
every view of valve or frustule its structure is not easy to define.
It appears, however, to be irregularly nodulose, and thicker and
much less translucent than the valve (Fig. 5). Having seen a
valve with both plates broken off, but yet with very little of the
edges of the valve deficient, and after carefully focussing on the
perfect valve, I confidently offer Fig. 6 as a representation of
an ideal transverse section of the valve.

It is, however, the living plant that is more interesting. I
cannot learn that it has been observed in this country in this
state, nor are there any figures extant. I first saw it adhering
to a' small specimen of GeramiuTn grcecillimum Griff, et Harv.
collected at Brighton in Sept. 1884, but the diatoms were not
numerous. Since then I have observed it not infrequently in
small numbers on filamentous algae, usually on the older por-
tions. But at Swanage in Aug. 1890 it was growing on
Calothrix conforvicola Ag. in sufficient quantity and in a state of
conjugation so as to permit of more extended study.

The frustule is contained in a hyaline, gelatinous mass, of
symmetrical figure. Viewed laterally (i.e., what is usually

28 T. H. BUFFHAM ON CONJUGATION OF ORTHONEIS BINOTATA.

known as the " front view " of the frnstule) it appears as a
half or three-fourths of a sphere, its base resting on the host
(Fig. 10). When seen from a point vertical to the base the
gelatinous investment has an elliptical outline of similar pro-
portions to that of the frustule. But from the extremities of
the minor axis there are mammiform protuberances through
which pass long processes of the same substance : these we
might call tentaculoids (Fig. 9)„ And to avoid circumlocution
I venture to propose for the gelatinous investment of this and
some other diatoms the term perigloea.

The frustules vary in size from 42 by 30 /x to 23 by 18 fx. The
perigloea exceeds the dimensions of the frustule by about half in
length and breadth. Each tentaculoid, however, sometimes
reaches a length of 320 /jl ('0126 inch) while the diameter near
the mammiform part surrounding its base is 6 fx, and near its
apex 2 fi. Moreover their origin can be traced to those parts of
the frustule where the plates above described lie in apposition
(Figs. 9, 10).

With regard to the ordinary mode of multiplication by divi-
sion of the frustule when the stage shown in Fig. 10 is reached
I am inclined to the view that both frustules are discharged
from the perigloea, for this is so uniformly perfect in outline
that no signs of a rupture are visible, although, on the other
hand, it is rare to see a valve completely free from any perigloea.
A very early stage is drawn in Fig. 7. Later on the swellings
through which the tentaculoids are projected are prominent
while the tentaculoids themselves are as yet only short and thin
(Fig. 8).

We now come to the mode of conjugation. As in other
diatoms only the smallest individuals are concerned in this
process. A frustule which has completed, or almost reached, the
stage of self-division (as in Fig. 10), and is only 23 /x long, has
a bulbous addition to the upper part of its perigloea, into which
the double frustule rises. This speedily enlarges into a perfectly
spherical sporangium of 75 /x diam. The frustules occupy
the centre of this, and then the lower one imparts its
endochrome to the upper one. This upper frustule then
divides and forms two masses of endochrome which develop
into two sporangial frustules of exactly double the length and
width of the parent. One valve of the mother-f rustule is closely

T. H. BUFPHAM ON CONJUGATION OF ORTHONEIS BINOTATA. 29

applied to the upper side of the upper sporangial frustule, and
the other valve to the lower side of the lower frustule. The
old lower frustule — which, perhaps, we must not call the male
— is usually seen as two clean valves slightly separated and
lying nearly vertically to its old position (Fig. 11). Now in this
case the original perigloea, although deformed, remains at the
base of the sporangium, and the tentaculoids can still be seen.

The process of conjugation just described would fall under
Smith's I. class (Brit. Diatoiyiacecc, Yol. ii, Introd., p. xii) in
which " we have two parent frustules and two sporangia [i.e.,
sporangial frustules] as the result of their conjugation."

The new valves are exactly like the normal ones in siliceous
firmness and in other characteristics. As they are 46 jj, long,
and vegetative frustules have been measured to 42 /x in length,
there is no doubt that the sporangial frustules issue from the
sporangium (which may be seen empty and deformed) and
assume a perigloea and multiply in the way normal to diatoms.

This diatom seems to have only one British record, and that
is only of the valve. Roper published this in 1858 as Gocconeis
scutellum Ehr., var. y (Quarterly Journ. of Microscopical Science,
Vol. vi, 1858, p. 24, PI. iii, Fig. 9). He found this in one
gathering at Lyme Regis, and it is clear that he had not ob-
served the frustules in situ. In 1863 Grunow regarded it as a
distinct species and it became G. hinotata, Roper's valve being
var. stauroneiformis. (Verhandlungen der zoologisch-botanischen
Gesellschaft in Wien, Band xiii, p. 145, Tab. iv, Figs. 13, 14).
The same author in 1877 describes the valve as differing from
Gocconeis, and says " two long horns (in the living frustule)
project from it at the places where the semi-circular plates are
situated," and he regards these "horns" as distinguishing
Orthoneis from Mastogloia (Monthly Microscojoical Jouryi., Vol.
xviii, p. 177). The mode of conjugation described now would
certainly distinguish it from Gocconeis. Smith places the last
named genus in his III. class where a single frustule produces
a single sporangium [=sporangial frustule], (Loc. cit. p. xii,
PI. B.)

It seems clear then that the plates have some physiological
value. Whether the tentaculoids are of any assistance to the
organism in its " struggle for existence " is not evident to me,
and I have no suggestion of any value to make.

30 T. H. BUFFHAM ON CONJUGATION OF ORTHONEIS BINOTATA.

I submitted specimens of Orthoneis hinotata in situ to several
diatomists of wide experience, who, however, had never seen it.
I have pleasure in acknowledging my indebtedness to Mr.
Thos. Comber, F.L.S., who, following a slight clue, tracked it
down to the authorities I have thus, through his kind assist-
ance, been enabled to quote.

I may be permitted to add here a short note on conjugation
of Rhahdonema arcnatum Kiitz. {Journ. Queh. Mic. Cluh, Vol.
ii, Ser. ii, p. 131.) In a gathering sent me by Mr. W. H.
Shrubsole, of Sheerness, in Jan. 1889 I found all my former
conclusions amply confirmed. But — what was more interesting
— I noted at the same time three small specimens of Bh.
minutum Kiitz. only 18 fx wide (=-0007 inch). All of them
had the small frustules attached laterally, which in Uh.
arcuatum I considered males ;* and two of the specimens bore
single sporangia. These, pro tanto, confirm my former results,
and show that the phenomena are generic.

Explanation op Plate III.
Orthoneis hinotata Grunow.

Fig. 5. — Inner side of valve with plates projecting from the

edges. X 800.
„ 6. — Ideal transverse section of the same, x 800.
„ 7. — A frustule in very early stage of perigloea (girdle or

zonal view). x 400.
„ 8. — The same more advanced. A short, thin tentaculoid

passing through the mammiform protuberance.
X 400.
„ 9. — Vertical or valve view of mature frustule in which

the tentaculoids are seen to originate from the

plates. X 400.
„ 10. — Girdle or zonal view of a pair of frustules, the result

of self-division, x 400.
„ 11. — Mature sporangium containing two sporangial

frustules and the four old valves, x 400.

* In Bennett and Murray's Cryptogamic Botany, p. 423, 1 am incorrectly
reported as describing the male frustules attaching themselves to any part
" of the girdle " of the female frustule. The words " of the girdle " are quiire
contrary to my statement and should be omitted.

31

PRESIDENT'S ADDRESS.

By Dr. W. H. Dallinger, F.R.S., F.L.S., etc.

(Delivered March ISth, 1892.J

My duty to-night is rather the congenial one of having a
pleasant half-hour of friendly communion with fellow members
and fellow microscopists and workers, than the formal one of a
laborious inaugural address.

It is one of the distinctive features of this Club that the
element of friendliness and fellow-help runs through all its
work and all its workers, giving it its special place amongst all
kindred societies. It seeks the highest in its own department,
but knowing that the highest theoretical and practical efficiency
in the microscopist must begin in the simplest efforts, it aims
at the especial encouragement and aid of those who are
beginning; and, happily, this aid can be and is given, not
only in the genial spirit of fellowship, but with the efficiency
which is inevitable when, as in the case of this Club, some of
the most experienced and practical microscopists in the country
afford ready help.

If, as a club, we were not — as we certainly are — promoting the
interests of optical science and research into the more hidden
details of Nature, we should yet be doing a good work in induc-
ing men, who would otherwise perhaps less wisely spend their
leisure, to devote it to the intelligent understanding and
employment of our favourite instrument.

Hobbies and hobby-horses have come in for much serio-
comic reflection ; indeed, they constitute almost a perennial
theme. But after close observation of the men of my time, I
have no hesitation in affirming my belief that the men with
intelligent enthusiasm in reasonable hobbies constitute some of
the most enlightened and thoughtful men of a generation.
And, therefore, I believe that by increasing the membership of
our Club we are increasing the number of better citizens and
better men, as well as promoting the common scientific welfare.

32 president's address.

To some in this hall, the time seems not to have very long
passed when, in this country, almost all scientific work was
voluntary, and, in a sense, the majority of scientific Tvorkers
were amateurs. All that is changed now ; happily, science as
a profession is widely cultivated in all its branches, and our
country possesses some very fine, efficient, and original workers.
But this boon, great as it is, may be attended by a far from
impossible danger, a danger that some, at least, see looming
near — that is, the conclusion that now only the professional
men of science are doing serious scientific work; or, still worse,
the existence of a tacit assumption that sound scientific work
is only to be looked for from professional sources.

From the nature of the English mind and the history of
English science, the suppression of the amateur as an
important factor in certain classes of English research and
experiment would be, I believe, greatly to be deplored. And it
may be fervently hoped that scientific work of real value will
long continue to be done in this country by men who, though not
professional workers, are still intelligent and ingenious inves-
tigators of Nature.

No doubt amateur work of this sort, done alone, and without
the enlightenment and stimulus which comes from comparison
with similar or kindred work by other workers, is not wise.
The best results are not attainable in this way. A most
essential thing in any department of even amateur inquiry is
to know what has been done, is being done, or can be done.
And here, again, comes out the value of a club with aims like
ours. It is undoubtedly a feature of our immediate time, and an
indication of the broadening interest in the microscope and
microscopy, that clubs and smaller societies are being formed
in so many centres.

Five and twenty years ago, when my work in microscopy
began, there were many of our very large towns with no trace
of a society of microscopists. But in the interval between
then and now such societies have been formed, have flourished,
doing frequently valuable work, and then, nominally by the
exigencies of city life, have been broken up into three or four
clubs or smaller societies in suburban parts, leaving the parent
society often greatly enfeebled, if enabled to exist.

Now, my experience of these societies is, that although the

president's address. 33

intention was always a high one, that of making meeting easier,
and, therefore, mutual work readier, this is by no means the
inevitable consequence. There is frequently ultimate in-
efficiency, and, at times, a total dwindling away.

There can be small doubt, in my judgment, that all such
societies, especially in a city like this, if formed at all (and
there may be good reasons for forming them), should not be
considered as supplanting a central society such as ours.

Even with men of science and microscopists there is a sense
in which there is " power in numbers," but beyond this there is
influence in persons. Men, known and distinguished, whether
as professionals or amateurs, always exert upon younger and
aspirant minds an influence, while the esprit de coeur is not
without its effect ; and the larger communion and larger
opportunity for the comparison of work is always powerful.
Without doubt, it would promote the largest and best
interests of amateur microscopy, in both London and the great
provincial cities, if the sectional club in the suburbs, con-
ducted with great economy, was normally considered an
appendix to, and not a supplanter of, the original and central
society.

In the position I occupy to-night, it is, of course, easy to go
hastily over the work which has been done by the Club during
the year. But I doubt if this is complimentary, either to the
work done or to you, who have already received and discussed
it ; it carries with it, too, the defect of all cursory glances.
But I am constrained to refer to one subject to w^hicli our
attention has been called during the year.

I discussed last year the merits of the remarkable new
object-glass produced by the firm of Zeiss, having the great
numerical aperture of 1-60 and a magnifying power indicated
by 2'5 m.m. It was shown that while this glass had remark-
able properties, and formed a beautiful image, yet it w^as in-
efficient :

(1.) Because it was not provided with even an achromatic
condenser of equivalent angle, but was worked of necessity, if
all its N.A. was utilized, with a condenser of dense flint, with
both spherical and chromatic aberration absolutely uncorrected.

(2.) Since its N.A. was so great, it could only be illumi-
nated and its image formed through homogeneous media, com-

JouRN. Q. M. C, Series II., No. 31 3

34 president's address.

billing glass, mounting material, and immersion fluid, all
having alike a refractive index equal to this aperture.

Such a medium had been found, both for mounting the
objects and immersing, both the condenser with the mounting
slip and the front of the lens with the cover. But the mount-
ing medium has proved valueless because transient. All the
slides I have received from Germany have perished ; none has
lasted longer than five months. This is a block to a persistent
attempt to discover the real merits of the object-glass. It is
only by comparison under varying circumstances of a well-
known object that reliable conclusions can be drawn.

If, therefore, after laborious work such a slide has been
examined and its special points "logged" and carefully noted,
it is more than discouraging to find it, as a mounting, wholly
destroyed by a kind of disintegration in a few months.
But even such a slide could only be a mount of silicious or
calcareous bodies, such as diatoms, spicules, foraminifera, and
so forth. Animal or vegetable tissues, or minute organic forms,
as I pointed out, must be irretrievably destroyed by the only
mounting media which could be employed.

I expressed a hope that ultimately some medium, tolerant,
at least, of dead organic forms and animal and vegetable
tissues, might be discovered. It is not to-night, however, my
good fortune to report its discovery. But, happily, we are
never at a standstill. For some time we have been striving to
obtain a thoroughly monochromatic light for microscopical
purposes. With much confidence ammonia- sulphate of copper
solution was used, and various batches of blue glass, made both
in England and on the Continent. But when critically examined
they were found not to be monochromatic at all. We all
know that Hartnack constructed an arrangement of prisms,
afterwards made by Zeiss, for screwing on to the under side of the
stage, and throwing a not very widely dispersed spectrum on to
the image on the stage.

The defect of this was its feebleness. It could not be used
with a condenser; in fact, was made before the Continental
makers had yet perceived that the condenser was a vital and
practical part of the optical action of a microscope.

Clearly, therefore, no critical image with a lens of large N.A.
and considerable power could be produced by this means ;

president's address. 35

and its value as a monochromatic illuminator was not con-
siderable.

Yet it has for some long time been clearly seen that the ad-
vantages of true monochromatic light were great for special
purposes. It was made popularly manifest in detail by the
publication of Mr. Crisp's valuable "Aperture Table."

Thus, for example, it is readily discoverable by it that while
a lens of JS'.A. 1*40 will, by calculation, in white light (line E.)
resolve 134,974 lines to the inch, the same lens employed with
pure monochromatic blue light (line F.) will resolve 146,305,
that is to say, will show to the skilled observer 11,331 more
lines to the inch.

Again, an object glass having a numerical angle of 1'52 will,
in white light, reveal 146,543 lines to an inch ; but if illumi-
nated by pure monochromatic light, the same lens will reveal
158,845 lines to the inch, so that monochromatic light in this
case gives us an added power of 12,302 lines to the inch.

Now by the hypothesis of dilfraction spectra, as explanatory
of microscopic vision, that means, what in reality it is, a prac-
tical increase of numerical aperture.

But more, true monochromatic light really almost changes
an achromatic lens into an apochromatic one ; but the great
difficulty has been hitherto how to produce monochromatic
light which should be absolutely such, and yet be within the
reach of all, and under control as to its measure of intensity
when employed with high powers, so as to enable the worker to
employ a suitable corrected condenser.

Sunlight is undoubtedly the purest and finest source, but we
so rarely have the privilege of seeing and using it that, if we
could obtain it from limelight, or still better, from strong
lamp-light, it would be a universal boon.

Now, during the year Mr. Nelson has devised a very simple
and thoroughly practical piece of apparatus for obtaining a
good spectrum with either lamp-light t)r oxycalcium illumina-
tion, which allows the condenser to be used with every portion
of the spectrum at will, and gives light enough to work easily
with the violet end.

With this, beautiful results are attainable with lenses which
the apochromatics had superseded; in other words it gives
them a renewed value.

36 president's address.

But, as I pointed out when Mr. Nelson introduced this simple
instrument, I do not think that he claims for it what I believe
will be its largest result.

As we saw last year, and have repeated to-night, we are
practically, for the present, at the limit of our possibilities by
mere increase of N.A.

I believe it is held by practical opticians to be possible to
construct a lens with a N.A. of 2-0. But granted that the
working distance could be made sufficient, the mounting media
form, for the present, an insuperable difficulty.

For this reason many skilled theorists and practical micro-
scopists are looking to the diminution of the wave-length of
light in specially constructed object-glasses as a means of their
further improvement. Dr. Czapski has in a comparatively
recent paper dealt with this aspect of the question.*

The condenser, of course, would be inevitable, and all rays,
save those from a monochrome of the spectrum, would be
excluded; and these must have an intensity sufficient for all
purposes. But it may be certainly stated, as Dr. Czapski
shows, that by such means a lens with aN.A. of 1'40 would be
practically increased to 1'75 ; and so on with higher apertures
measured in white light when employed with the shorter wave-
lengths of the violet and blue rays.f

But the special point of interest is that with object-glasses
of far less N.A. in white light we can come very approximately
towards 1'60 and yet employ mounting media that will not
destroy, but permit of the examination of fine organic tissues.

Clearly, then, Mr. Nelson, with intelligent insight, has pro-
vided us with exactly the means we require for using with the
utmost advantage our best achromatics, and for getting the
greatest optical res alts possible from our most perfect apochro-
matics of large aperture.

All this, of course, applies to the higher reaches of the micro-
scope and its work in research, and it would be a mistake indeed
if these were not included in the work of a society like this.

It may be as well to note here that a solution is in use
by some microscopists which, although I have not tested it, I

* " Probable Limits to the Capacity of the Microscope," p. 814, ' J.E.M.S.,'
part vi., 1891. ". Zeitschr. f. Wiss. Mikr.," viii., 1891, pp. 145-55.
t Ibid.

president's address. 37

learn from excellent experimenters is practically monocliro-
matic. It is easily prepared and used, and although it yields
with lamp-light an orange light slightly tinged with greenish,
gives, for critical purposes, some beautiful results.*

It will not, I feel assured, be inferred from the consideration
I give, and from time to time have given, to the higher or
highest powers of the microscope, that I am unconcerned for,
or have but little interest in, the object-glasses of low and
moderate power and the work to which they are applied.

The fact is, that properly used, the dry apochromatic object-
glasses from an inch to a quarter of an inch in focal length
leave relatively little to be desired ; they are, so far as they go,
optical triumphs. Kot that they put a limit to my anticipa-
tion of what may be ; I look beyond them, in hope, and even, as
I think, in reasonable anticipation, to what is a still nearer
approximation to perfection. But that must be when physics
and chemistry have opened up new resoui^ces to the optician.
It is impossible to anticipate what may be discovered for us by
the steady and j^ersistent search of science into nature. That
new resources will present themselves to the electrician or the
photographer, we do not hesitate to believe. All recent history
makes the conclusion inevitable. I know of no reason why, in
like manner, some new possibility should not open itself to
practical optics. I see as much possibility of optical advance
in the futui^e as in the past.

Meantime, however, the workers with low aiid moderate
powers of the finest construction (and they are ilow produced at
such moderate prices as to be fairly within the reach of most)
may well congratulate themselves on their possessions, and
work with a zest which their instruments certainly justify.

Not only are the lenses good, but the optical appliances for
employment with them are equally admirable.

We have passed the period when it was believed that all low
power and moderate lenses might be used without condensers.
Every compound lens is caused to do its best work with an
achromatic condenser adapted to its N.A. and its focal length,
and happily to-day these are accessible to all workers.

* The solution is prepared as follows, viz. : — Sulphate of copper, 2ozs.
lidrs. ; bichromate of potash, Idr. 2scrup. ; sulphuric acid, 12min. ; water,
65OZS.

38 PRESIDENT'S ADDRESS.

And when we remember what immense areas of research
accessible to low power workers remains ready and waiting to
be done, truly there need be no Alexander-like weeping for
more worlds to conquer.

In this society we have yearly evidence of this, as, for example,
in the Fresh Water Algae, the Rotifers, the Oribatidee and
Acarina generally, and in other subjects.

But even in microscopy there is, unfortunately, a fashion — a
tendency to a merely curious repetition of the work of others
— not so much it may be with a scientific purpose as by the
mere result of attraction by the newness of the objects. This
was true of tissue cutting and staining, especially of differential
staining.

It is true of the mere mounting and staining of Bacteria and
many other matters. Not that I would, to such a group of
workers as this Club represents, suggest a reflection by this ; it
is simply recalled by the fact of the beautiful work done in our
very midst, and by one of our past Presidents, on so common an
object as the Blowfly. There are hundreds of similar " common
objects " awaiting work with solid persistence and moderate
powers, which many of us could really do in our leisure,
and by such work could enrich ourselves and benefit the
world.

As a single illustration, may I suggest the Spider ? True,
a great deal of beautiful work has been done concerning the
anatomy of spiders, and their classification has been much
considered. No doubt, however, much remains to be done,
even here. But it is the work and habits of this group that
has been so comparatively neglected.

Some really beautiful work has been done, even in the
microscopic investigation of this subject in regard to Epeira,
within the last few years.

But this makes even more suggestive the possibilities of
work undertaken on this group. And I can speak the more
confidently because for the last five or six years my summer
vacations have been spent in their study ; not so much with the
hope of working out new facts as of fully familiarizing myself
practically with the old and the more recently investigated.
My time would admit of no more ; but I am convinced of the
delightful possibilities of the subject to a naturalist and a

president's address. 39

microscopist of resource and resolution. There is still one
subject on which I would fain be permitted to offer, for what
it may be worth, a suggestion.

I am afraid that the very word " influenza " has become so
repugnant to us all that almost the sight or sound of it becomes
a metaphorical " breach of the peace." None the less we all
desire to see it mastered. There is an almost universal convic-
tion amongst the faculty that it will ultimately be found to
take its origin in some one or more forms of pathogenic
Bacteria.

Between the search for such a form as a cause of a specific
disease and the working out of the life-history of saprophytic
organisms there is a wide interspace. Hospitals and hospital
laboratories are alone the places in which the former work can
be done, and it should, nay must, combine the knowledge of
the pathologist and physician with the skill and manipulative
ability of a microscopist of patience and resolution.

Moreover, it is now well and clearly recognized that the dis-
covery of even an unusual form of bacillus or bacterium in the
secretions of a patient, living or dead, is by no means a
reason for announcing the discovery of the cause of a specific
disease.

Now my investigations into the nature and characteristics of
bacteria were commenced before certain forms were demon-
strated to be specific viruses, before the nature of the patho-
genic bacteria was fully demonstrated. Moreover, this was, in
my case, only a lateral study to that of the monad group
known as Saprophytes ; hence, while some of my work led me,
as it were, to the very edge of pathological inquiry, I was
obliged to leave it there, having neither special medical train-
ing nor proper opportunity for its further pursuit on the patho-
genic side.

But I am deeply interested in all researches of this nature,
and have followed with some care most of the efforts made to
endeavour to trace the origin of influenza to bacterial forms.

What has struck me in following the work done in this
direction is the great variety of organic bodies, not only of the
usual bacterial order, but from the observations of some
specialists even what appear to be saprophytic forms have
been found in the blood of patients.

40 president's address.

Thus Prof. Klebs, of Zurich,* giyes the results of his
e:^ainination of several distinct cases of influenza, and finds
in the blood of the patients a large number of highly re-
fractile, mobile bodies, in size, form, and modes of motion
resembling bodies which he has met with in pernicious
anaemia, though in greatly reduced numbers.

This was found to be the case in an instance of fatal
influenza, in blood " removed with every precaution " from
the heart of the subject; the "monads" — for such he calls
them — were easily seen and demonstrated in this. They varied
in size, were oval in shape, and not only possessed a vibratory
movement, but were capable of distinct locomotion.

It is significant that they were often attached to the margin
or imbedded in the substance of the blood-corpuscles.

They were distinctly flagellated, and certainly recall to us
the form and manner of saprophytic forms.

Prof. Y. Babes very carefully investigated thirty-one cases
of influenza with all the skill for which he is celebrated. He
endeavoured to show that there exists a series of bacteria
which, in their growth and shape, are approximate to, or
identical with, Pasteur's sputum bacteria on the one hand,
and on the other to Streptococcus pyogenes. "^

Herr. I. Prior examined fifty-three cases of influenza.;}:
Twenty-nine of these were without complications. His re-
searches also showed the constant j)resence of Streptococcus
pyogenes, and also Staphylococcus pyogenes aureus ; these were
present in all secretions.

In the same way Herr E. Levy§ found that on examining
eighteen cases of influenza the Diplococcus pneumonice was
present in seventeen of these, while occasionally he found
also Streptococcus pyogenes and Staphylococcus pyogenes albus.

Again, Kowalski|| examined sixteen cases of influenza, and
isolated three kinds of micro-organisms which he believed to

* " English Mechanic," p. 525, 1890.

t "Ceutralbl. f. Bakteriol. u. Parasiteuk," vii. (1890), pp. 460-4, 496-502,
533-8, 561-8, 598-606.

X " Muncbener Med. Wochenschr.," 1890, Nos. 13-15. Vide " Centralbl.
f. Bakteriol. u. Parasiteuk," vii. (1890), pp. 705-7.

§ " Berlin Klin. Wocbenschr.," 1890, No. 7. Vide " Centralbl. f. Bakteriol.
u. Parasiteuk," vii. (1890), pp. 701-3.

II " Wiener Klin. Wocbenschr.," 1890, Nos. 13 and 14. Vide " Centralbl.
f. Bakteriol. u. Parasiteuk," vii. (1890), pp. 701-3.

president's address. 41

be unknown. The first resembled the typhoid bacillus ; the
second variety formed snow-white colonies on the surface of
the gelatin, which was liquefied ; the third kind grew best in
agar, at incubation low temperatures, and in twenty-four
hours appeared as colourless drops.

Besides these he was able to isolate Staphylococcus pyogenes
aureus, also alhus, and citreus, Diplococcus pneumoiiice, Strepto-
coccus pyoge?ies, Staphylococcus cereus, also albus and Jlavus, all
of which were found in the secretions of the same group of
cases.

Dr. Marmerek examined the bronchial secretion of eight
well-marked influenza cases,* and in seven of these found
abundance of organisms which could only be considered Diplo-
coccus pneumoni(T,. In six cases there developed on agar plates,
colonies about the size of poppy seeds, of irregular shape, of
great firmness, of a blackish brown colour, and with indented
outline. These cocci formed chains of from two to forty
individuals.

Herr Bein examined twenty cases of influenza,t ^'^^ found
Diplococci, Streptococci, and Staphylococci in every instance. His
conclusion is one of some importance, for, first, he does not
regard the diplococcus, which he invariably found as being
strictly Diplococcus pneumonice ; and, second, he concludes that
the disease is due to the co-operation of several different kinds
of micro-organism, no specific microbe being, in his judgment,
discoverable.

In the same manner Sig. S. Sirena,J in numerous similar
examinations, found what appeared to be Diplococcus pneumonice,
together with numerous other micro-organisms, and infers that
there is no specific contagium discoverable.

Dr. Bouchard,§ after careful examination, found in the
influenza cases he investigated three pathogenic microbes,
accompanying every case, and pertinently remarks that two of
these " are too many, if we go for a specific virus of influenza."

* " Wiener Klin. Wochenschr.," 1890, Nos. 8 and 9. Vide " Centralbl. f .
Bakteriol. u. Parasiteuk.," vii. (1890), pp. 509-10.

t " Zeitschr. f. Klin. Medicin./' xvii. (1890), No. 6. Vide " Centralbl. f.
Bakteriol. u, Parasiteuk.," ix. (1891), pp. 171-2.

X "La Eeforma Med.," vi. (1890), p. 680. Vide "Centralbl. f. Bakteriol.
u. Parasiteuk.," ix. (1891), pp. 174-5.

§ La Semaine Med.,^ 1890, No. 5. Vide " Centralbl. f. Bakteriol. u.
Parasiteuk.," vii. (1890), pp. 375-6.

42 president's address.

So Dr. T. Prudden,* after very close investigation of seven
cases of strongly pronounced influenza, discovered Staphylococcus
pyogenes aureus, Streptococcus pyogenes, and Biplococcus pneu-
monia'., and, as a result, concludes that " bacteriology has
brought to light no living germ which there is reason to
believe has anything to do with causing the disease."

It thus becomes fairly manifest that a remarkable variety of
pathogenic forms have been discovered by a great variety of
careful workers, in widely separated localities, associated with
the same specific disease.

Now mere speculation is scarcely tolerable in the treatment
of a scientific question ; but when we are in complete darkness
on so important a subject, and are earnestly struggling to find
the light, even speculation or inferential inquiry may scarcely
be out of place, especially when the freedom from certain
restraints, which a position like mine of to-night affords, offers
itself.

It will be remembered that I have spent, and am still spending,
time and effort in endeavouring to discover how far the sapro-
phytic organisms — so closely kindred to the pathogenic microbes
— are capable of being changed by continuous, gradually im-
posed, and prolonged changes of environment.

Some extremely interesting and suggestive results have been
attained, which I am not in a position at this time even to
indicate. The final results can only be obtained by persistence,
patience, and years.

But I have already been able to publish some results which
are, up to the point that they carry us, capable at least of
suggesting further research. For in less than ten years the
saprophytic organisms that are normal at a temperature 60° F.
were trained to live, even with increased fecundity, at a tempera-
ture of 157° F., and yet the normal adult organisms, which had
not been so trained by prolonged and cumulative change of
environment, are always hilled by immersion at a temperature
of 140° F.

Now with this alteration of function no important change of
form was at all visible. It was simply a modification of func-
tion.

This, and the subsequent work T have been doing, has been

* " Medical Record," Feb. 15, 1890.

president's address. 43

convincing to me that it is physiologically and not morpho-
logically that the saprophytes are subject to mutation, so much
so that unless we take a very broad and philosophical view of
what is specific, we may even appear to approach by such
mutation a physiological specificity concurrently with a morpho-
logical identity with unaltered forms.

The remarkable morphological similarity of certain bacilli,
whose physiological differences are terribly unlike, must strike
a very casual observer.

Now I do not for a moment suggest that any case in which
putrefactive forms have, by change of environment, changed
their functional specificity so as to become pathogenic has
ever been made out.

Nothing of the sort has been done ; but what I would sug-
gest is, that the possibility of doing this is worthy of sincere
consideration and experimental research.

That certain physiological changes can be readily brought
about in the saprophytes there can be no doubt. How far may
these, if constantly taking place in nature, at times fill the air
with minute organisms in vast clouds, which by certain altered
conditions have become endowed with functional characters
inimical to man and beast, taking for a time the place of
common forms with which the air is usually charged, but as
a rule innocuous to man and beast ?

Let it be remembered I am suggesting, not affirming ;
inquiring, not stating.

Certainly the examination by Prof. Klebs, of Zurich, of
the blood of influenza patients is more than noticeable. So
far as I know distinctly monad forms are putrefactive. Klebs
finds them in the blood from the heart of patients dead from
influenza. More striking still, they are oval in shape, have
distinct power of motility, and are found " attached to the
margin or imbedded in the substance of the blood corpuscles."

This is distinctly the action of saprophytic monads. But
that we are told that " every precaution to a^oid contamina-
tion " w^as resolutely taken, and this would inevitably involve
rapid investigation after death, we might have concluded that
it was the evidence of advanced decomposition that we were
studying.

But I think this would be a scarcely just conclusiori.

44 president's address.

It is, of course, understood that the function of the sapro-
phytic organisms is, to instantly attack dead organic struc-
tures ; whether or not their own vitality may be increased by
certain modifications of environment, so that they may be able
to attack living organic tissues whose vitality has been greatly
reduced is a point which I believe extremely worthy of atten-
tion. I have certainly seen indications that this may be so.

But what is even more to our purpose is, that the whole of
the large number of competent observers whose results we
have reviewed, have agreed in discovering in influenza patients,
alive or dead, a rather motley group of bacteria, no one of
which is known to be possessed normally of the function of
producing the symptoms commonly known as influenza.

It is, of course, possible that this affection may not originate
in any microbic form ; nevertheless analogy points strongly in
that direction, and the question which to my mind needs as
early an answer as it can obtain is this, viz., seeing that the
kindred forms to the pathogenic bacteria, viz., the saprophytic
organisms, are eminently mutable in Junction, although com-
paratively stable in form, is it not possible, and, therefore,
worthy of close inquiry and research, that the several and
various forms of bacilli and other bacteria found in influenza
patients may not, by some means not now known to us, have
become possessed of functions which make them in that state
virulent to man ?

I venture to believe that the question of the functional
mutability of these organisms and its causes and consequences
will form some considerable portion of the work of the next
quarter of a century.

45

Binoculars.

By E. M. Nelson, F.R.M.S.

(Mead May 20th, 1S92.)

There has been a great deal of unnecessary confasion caused
by Prof. Abbe's unwarranted attack on the late Dr. Carpenter's
views with regard to the stereoscopic binocular.

Dr. Carpenter stated that orthostereoscopic effects can only be
seen in an inverting microscope,* when there is a "cross-over,"
and that, if there is no " cross-over," the image will be pseudo-
stereoscopic ; but with an erect image,t if there is a " cross-
over," the image will be pseudostereoscopic, and with no
" cross-over," orthostereoscopic.

Prof. Abbe takes exception to this statement of Dr. Car-
penter's ; he puts the above proposition in another form, saying
what is practically the very same thing, and of course arriving
at the same results ; but Abbe puts it in such a way that, while
he appears to say something very different to what Dr. Car-
penter says, in effect, however, he does not, and this I hope to
clearly demonstrate to you.

Of the two theories, however, that of Dr. Carpenter's is the
more complete. In the first instance, we must divide the sub-
ject into two parts : —

1. The "cross-over" orthostereoscopism and pseudostereo-
scopism.

2. The origin of the dissimilar images.

The essential point in orthostereoscopic vision with a micro-
scope is that " the ordinary view " of objects be maintained.

* " Inverting microscope." It must be especially borne in mind that an
ordinary inverting microscope transposes the image as well as inverts it.
The inversion does not affect the question at all; it is the transposition which
may or may not accompany the inversion that is the all-important point.
I have adhered to the term " inverting microscope '' because the phrase
transposing microscope might lead one to suppose that it was not the
ordinary instrument that was meant.

t So, too, in an erect image it is the non-transposition that is of import-
ance.

4t) E. M. NELSON ON BINOCULAES.

Let US, for example, take away the compound body, eye-pieces,
prisms, and all other gear, leaving only the objective, which we
must suppose " sawn in two " (see specification of Holmes'
patent binocular, " R. M. S. Journal," 1870, p. 274), and apply
the right eye to the right half and the left eye to the left half
of the objective, we shall then obtain an orthostereoscopic
picture. This is a simple ideal case of an erect image with a
simple microscope ; it can be practically carried out by means
of Beck's prisms,* which neither " cross-over " nor transpose
the image.

If we interfere in the slightest with these relations by either
a transposition of the image or a "cross-over," pseudostereoscopic
vision will be the result. While admitting: that there mis^ht be
a difficulty in " sawing in two" an objective and using it as
indicated above, we may nevertheless think of it as a practical
construction of simple microscope.

I am not aware that Dr. Carpenter anywhere states the case
in precisely this manner, but the above is the spirit and mean-
ing of what he has written.

If you take either Holmes' " sawn in two " objective, or Beck's
binocular simple microscope, and make an ordinary compound
microscope of them by appljang tubes and ordinary Huyghenian
eye-pieces, pseudostereoscopic vision will ensue, because you
will have a transposed image without a " cross-over."

If orthostereoscopic vision is required, the transposition
must be corrected, and " the ordinary view " restored, either by
a " cross-over " or by a retransposition of the image by means
of transposing prisms or erecting eye-pieces.

Now, what does Prof. Abbe say ? The cross-over is not of the
slightest importance ! f Yet he states it is necessary that the
eye-spot images (which are the images of the objective) should
be in a certain condition, which condition can onh^ be obtained
when the conditions required by Dr. Carpenter are implicitly
ob9|^ed.

There is a good deal, however, that Abbe significantly leaves

* This I have called Beck's binocular, because it is now only to be found
in Beck's binocular dissecting microscope ; it was, however, invented by
Riddell (1851), and reinvented by Wenham (1853). " R. M. S. Journal,"
pp. 1-18 (1854).

t " R. M. S. Journal," 1881, p. 204, " all other circumstances except this
one^' (the nature of the eye spots) ^^ being immaterial."

E. M. NELSON ON BINOCULARS.

47

unsaid, and if a careful reader will fill up the hiatus he will
then see that the professor's conclusions coincide with those of
Dr. Carpenter, excepting only that Abbe's are imperfect, and
do not meet every case.

Prof. Abbe says that the eye-spots for orthostereoscopic
vision must be like this, Q D ; but he does not tell you that Q D
in an inverting microscope without a " cross-over," and in an
erecting microscope with a "cross-over," is an impossibility.
He says that the eye-spots arranged like this, DQ, give pseudo-
stereoscopic images ; but he does not say that in an inverting
microscope with a " cross-over," and in an erecting microscope
without a " cross-over," the attainment of that arrangement is
impossible.

Prof. Abbe's law with regard to eye-spot pictures is only a
partial one ; suppose, instead of dividing the objective, you have
two whole objectives. How will his law help you ? The
Cherubin d' Orleans' binocular is a case in point. The eye-spots
are neither QD nor DQ, but are circular, and, according to
Abbe, the presence or absence of a " cross-over" has nothing to
do with the question. Therefore by the Abbe theory it is quite
impossible to state whether the Cherubin d' Orleans' binocular
is " ortho- " or "pseudo- " stereoscopic. According to Carpenter,
however, it is plain enough. The microscope
is inverting ; it has no " cross-over." The
image is, therefore, pseudostereoscopic. The
question also arises of the interpretation of
the images with a single objective, when a stop
like Fig. 4 is placed at the back of the objec-
tive, with, say, a Wenham
binocular. The eye-spot
images would be circular
(Fig. 14), and in the absen
of the unimportant (?) know-
ledge of either the trans-
position of the image or the "cross-over," how is one to say
whether the image is "ortho-" or "pseudo-" stereoscopic.
Here, again. Dr. Carpenter's theory meets the case, while that
of Prof. Abbe fails.

The identity of Abbe's system, as far as it goes, with' that of
Carpenter can be clearly seen by tracing the rays through

y

48

E. M. NELSON ON BINOCULARS.

the various forms of binoculars. Thus let the marginal rays be
called mM and the central cC, the left hand portion being
in small letters, and the right hand in capitals ; the aperture of
the objective (say, the back lens) will be represented by mc CM.
When the image is inverted the letters will be inverted thus, rao
MC- By this means transposition, cross-over, and inversion
will be made clear.

The following table shows how the rays leaving the objective
in the order mc C M emerge at the eye-spots.

Table showing what portions of the objective image are visible at
the eye-spots of various binoculars.

Left hand marginal ray at back of objective m

Rigbt „ „ „ „ M

Left hand central ,, „ c

Right „ „ „ „ ...... C

Position of rays at the back of objective mcCM

When the letters are inverted the image is inverted, other-
wise the image is erect.

Name of Binocular.

Abbe

Beck

Cherubin d'Orleans

Holmes

Nachetl

Nachetll

Powell

Stephenson

Tolles

Wenham

Orthostereoscopio.
Left eye. i Right eye.

lAlO

mc
mc

lAIO
lAlO
lAlO

mo
mc

lAlO

otn

CM
CM

OttI

Ota
oiu

OIAI
CM

om

Pseudostereoscopic.
Left eye. Kight eye.

lAlQora

oiu

OIU

lAlO

R

lAlO ow
lAlO

I/MO
lAlO

The following example shows how by my table the effects
can be at once traced without the necessity of a diagram when

E. M. NELSON ON BINOCULARS. •*«

an erector is placed either in front or behind the Wenham
prism. If it is placed in front of the Wenham prism, ^.e.,
between the prism and the objective, we have at the back of
the objective mc CM, at the back of the erector lAlO oin, after
the cross-over, by the Wenham prism, ora lAIO. After the trans-
position and inversion at the eye-piece mc CM, the "ordinary
view" is restored; it is, therefore, orthostereoscopic. When
the erector is placed behind the Wenham prism, i.e., between
the prism and the eye-piece, we have at the back of the objec-
tive mc CM, after the cross-over by the prism CM mc. After the
erecting eye-pieces no change takes place ; CM mc is not the
" ordinary view," consequently the image is pseudostereoscopic.

There are four conditions for orthostereoscopism, viz. : (1)
mc CM ; (2) nio OIAI ; (3) lAlO oui ; and (4) MC cm. (1) is the
" ordinary view ;" examples, Beck's simple microscope and
Tolles' compound ; (2] the "ordinary view " inverted ; example,
Stephenson's without the erecting prism ; (3) example, Wen-
ham, N'achet is precisely the same as (1), and (4) is the same
as (2). If w^e suppose a cube placed on a table it matters not
whether we stand in front of the table or go to the other side of
the table to view the cube ; in both cases we will obtain ortho-
stereoscopic effects. The same is true with the microscope ; it
matters not whether we stand behind or in front of a binocular.
If when standing heliincl a microscope we have the " ordinary
view " (1), in front of the microscope we get (3). Again, if
when hehind the microscope we have the " ordinary view "
invented (2), in. front we shall get (4).

There are also four conditions for pseudostereoscopism, viz.,
the non-" ordinary view " (5), cm MC, its inversion (6), oiu
lAlO (7), the front view of (5) OIAI uio, and (8) the front view
of (6) CM mc.

We have, therefore, only two things to remember — 1st : The
"ordinary view," mcCM. 2nd: The non-" ordinary view,"
cm M C ; the rest are only the inversions of these two and the
four front views.

Taking the binoculars in their alphabetical order we find
that Abbe's is an inverting and transposing binocular eye-piece.
Without the semi-circular eye-piece caps* the arrangement at

* Stereoscopism was obtained by dividing the eye spots, by Wenham.
"Journal E. M. S.," 1854, p. 4.

JouRN. Q. M. C, Series II., No. 31. 4

Ti^.70

50 E. M. NELSON ON BINOCULARS.

the eye spots is |/\|q ora, |/\|0 oin, and as the images are precisely
similar the binocular is non-stereoscopic. By means of semi-
circular eye-caps the inner halves of the eye-spot images are
cut out, a differential image is thus obtained, and a " cross-over "
effected, which results in orthostereoscopic vision, because the
transposition is corrected. If the outer halves are cut out there
is no " cross-over," and as the transposition remains, pseudo-
stereoscopic vision is the result.

Dr. Mercer* has pointed ont that the inner halves of the
eye- spots may be cut out by screw-
ing in the tubes (Fig. 10) and the
outer cut out by screwing them
apart. This method of using the Abbe eye-piece is preferred
by some to the employment of the semi-circular caps, which
they find uncomfortable.

In Beck's binocular simple microscope " the ordinary view "
is not interfered with, and consequently it is orthostereoscopic ;
the objective is divided by prisms. Cherubin d'Orleans (1677),
an early binocular, is pseudostereoscopic because there is no
" cross-over," and the microscope transposes and inverts the
image ; the letters l and ii denote the left and right hand
objectives.

Holmes' " sawn in two " objective was, as first made, pseudo-
stereoscopic, the image being transposed and inverted without
a " cross-over ; " afterwards it was fitted with erecting eye-
pieces, which restored "the ordinary view" and gave an
orthostereoscopic image. ,

I^achet I.f The first is a three-prism form with inversion,
transposition, and a " cross-over."

Nachet II. is a two-prism form, which transposes and inverts;
it is constructed so that by a movement of the prism it will
yield either a "cross-over" or no "cross-over, "and consequently
both " ortho- " and "pseudo-" stereoscopic images can be
obtained. In this as well as in the preceding form a prism
divides the objective.

Powell is, strictly speaking, a non -stereoscopic binocular,
the images in each tube being precisely similar. It was

* "Proceed. Amer. Soc. Microscopists," 1882, p. 129, and " E. M. S.
Journal," 1882, p. 271.

t " Journal K. M. S.," 18,54, p. 74.

E. M. NELSON ON BINOCULARS. 51

designed as a non-stereoscopic binocular for use with liigli
powers ; if Dr. Mercer's method of racking in or out the tubes
is used " ortho- " or " pseudo- " stereoscopic vision will be
obtained. The conditions are precisely similar to those of
Abbe's ; repetition is, therefore, unnecessary.

Stephenson.* We may best consider this as a Holmes'
" sawn in two " binocular of the pseudostereoscopic type, used
in conjunction with a pair of Wheatstone's pseudoscopic
spectacles. (Wheatstone's pseudoscopic spectacles consist of
two transposing prisms.) Stephenson's prisms are similar to
Wheatstone's, and neutralize the transposition of the images
by the eye-pieces, thereby restoring "the ordinary view," with
the exception of the inversion, which is left, and which does
not influence the stereoscopism at all. In most binoculars of
this type there is another prism to correct the inversion ; the
resultant image, therefore, is erect, and not transposed, but
this binocular is orthostereoscopic whether the image is erect
or inverted. This ingenious binocular was first invented by
Riddellf in 1851, was shelved, and independently reinvented
by Stephenson in 1870. In passing, let me say that the
Cherubin d' Orleans binocular would make an excellent ortho-
stereoscope with the addition of two carefully-worked Wheat-
stone's transposing prisms placed between the lenses of the
Huyghenian eye-piece.

Tolles' binocular eye-piece is the same as Nachet I., with an
erector placed between the objective and the dividing prism.

Wenham.| This excellent orthostereoscopic binocular passes

* '* The non-inclining form alone is considered ; I have left out the
erecting prism, which only erects and does not transpose the image, as it
does not affect the stereoscopic conditions, and only introduces unnecessary
complications.

t " Journal R. M. S.," 18.54, p. 20. See also 1892, p. 98.

\ The development of this prism is interesting, and now almost forgotten.
The first arrangement was similar to that now known as Beck's dissecting
microscope, and when applied to the compound microscope gave pseudo-
stereoscopic pictures. It was also applied by Wenham above the eye-
piece ; this gave orthosteoroscopic images with a contracted field. The
second was an achromatic combination of three prisms not unlil^e an
achromatic concave cylindrical lens — there was transposition without a
cross-over ; it was, therefore, a pseudostereoscope. These date (1853) and
are figured in " R. M. S. Journal," 1854, p. 1. The third form was also an
achromatic combination of three prisms resembling an achromatic convex
cylindrical lens. In this case the transposition was corrected by a cross-
over; it was, tiierefore, orthosteoroscopic (" R. M. S. Journal," 1860, p. 155).
The fourth was the Wenham prism in its present form (" R. M. S.
Journal," 1861, p. 15).

52 E. M. NELSON ON BINOCULARS.

the left-hand half of the objective to the right eye direct, the
right half being deflected by a prism to the left eye. It would,
were it not for the transposing effect of the eye-pieces, give
pseudostereoscopic vision. This is by far the most practical
a,nd best of all orthostereoscopic binoculars. There is plenty of
light, the images in both tubes, if the prism is well made, are
excellent, and the great ease with which the instrument can be
converted to a monocular, together with its simplicity of con-
struction, will always cause it to hold the first place.

The Abbe is an indifferent instrument ; it yields a double
image in the side tube, and while contracted tubes are found
more agreeable to use than the semicircular eye-caps, neither
can be called pleasant to work with.

The Beck is a very good plan for a simple microscope. It is
better to make it with a single prism on either side, instead of
four prisms, in which case it must be adjusted for the observer's
own use, as it will not be possible to alter the adjustment to
suit different distances of eye centres.

The Cherubin d'Orleans yields excellent results, but the con-
struction is only possible with low powers ; nevertheless, the
stereoscopic effect is more perfect than in any other form.

Holmes can hardly be called a practical construction.

ISTachet II. — I have not tried this form, but should think that
if the two prisms were joined into one it would be an improve-
ment, and would make a very efficient orthostereoscope.

Powell is a very good non- stereoscopic binocular.

Stephenson is the best erecting binocular. The prisms re-
quire to be very carefully worked.

Tolles is the best binocular eye-piece, but the prisms require
most careful working.

The Wenham we have already discussed. Mine, with a prism
by Powell, gives excellent results, e.q.^ the secondaries of a tri-
ceratiumin balsam are shown in both tubes by a | of SS*^ and a
power of 80 diameters.

An examination of the table shows the identity of Abbe's
theory, as far as it goes, with that of Carpenter. Abbe's
theory is shown by the cC being in the middle for orthostereo-
scopism, and the mM in the middle for pseudostereoscopism.

Abbe's conditions of Q D and D Q do not indicate the pre-
sence or absence of a " cross-over," which my table does.

E. M. NELSON ON BINOCULARS. 53

Moreover, these conditions of Abbe's are non-essential, because
the most perfect stereoscopic eifect, either "ortho" or "pseiido,"
is obtained when tlie eye spots are circular.

The table shows that Carpenter's law in every case holds
good, e.g., for orthostereoscopism either " the ordinary view "
mast be preserved or transposition must be corrected by re-
transposition or a "cross-over."

In addition to what may be called the ordinary conditions of
stereoscopism, Abbe introduces a new and extraordinary one,*
viz., that "orthoscopic vision is always obtained when the right
half of the right pupil and the left half of the left pu^Dil only
are employed."

With regard to this an editorial note in the " R. M. S.
Journal " says if — " Prof. Abbe properly points out what has
hitherto not been appreciated, that stereoscopic or pseudoscopic
effect does not depend essentially on crossed or not crossed
axes, but upon either the outer or inner halves of the pupils of
the observer's eyes being put into action in binocular vision."

I wish to point out that it makes not the slightest difference
in the image, whether the whole or a part, whether the top or
the bottom, w^hether the right hand or the left hand 23ortions of
the pupils of the eyes are utilized.

Dr. Mercer's method of obtaining orthoscopic vision without
eye caps, by making the* iris cut off the inner halves of the eye
spots by racking in the tubes, proves the truth of this assertion,
because the inner halves of the pupils only are utilized (Fig.
10).

Dr. Mercer's method is entirely opposed to this theory of
Prof. Abbe. I have frequently tried it, and find the stereo-
scopism quite as strong as with eye caps.

The duty of the eye caps in Prof. Abbe's orthostereoscopic
binocular is to effect a cross-over. Whatever influence they
may have on the pupil of the eye is quite immaterial. The
contradictory statements in this paper of Prof. Abbe's are
remarkable, for, speaking of the arrangement of the semi-eye
spots, he says % that "it is quite indifferent whether the effect
is obtained with crossing or non-crossing rays, whether the
image be erect or inverted or semi-inverted, and whatever

* " R. M. S. Journal," 1881, p. 204. f " R. M. S. Joiarnal," 1881, p. 299.
X " R. M. S. Journal," 1881, p. 204.

64 E. M. NELSON ON lUNOCULAllS.

elements (lenses, prisms, mirrors, etc.) may be components of
the optical arrangement."

A few pages farther on we read : — * " Whether or not under
these circumstances orthoscopic action will require crossing-
over of the rays from the right hand half of the objective to
the left eye piece and vice versa depends solely on the manner
in which the delineating pencils are transmitted through the
system." On the same page he says : — " In the Wenham and
the Nachet binoculars consequently crossing over is required; "
and on the next page : "In Stephenson's binocular such cross-
ing over is not required." Thus the things Avliich are " im-
material " on page 204 become under precisely the same condi
tions " essential " on page 209.

Abbe's conditions are — 1st, non-essential ; 2nd, incomplete ;
3rd, misleading ; 4th, in no instance do they conti*avene Car-
penter's dictum ; and 5th, with regard to the action of the
pupils of the eyes they are incorrect.

We have now come to the second portion of the subject, viz.,
the origin of the dissimilar images.

Carpenter says the origin is " perspective," but Abbe "paral-
lactic displacement."

Stereoscopism is a difficult subject, and one which for sol ation
does not lend itself entirely to mathematical demonstration. It
is so inseparably mixed up with mental action that it can hardly
be dealt with by either optical or mechanical lines of argument.

Stereoscopism or " solid view " can be obtained by one eye,
for if you shut one eye a book appears solid with the other eye,
but solidity is better and more perfectly seen with two eyes.

With simple microscopes (loupes) solidity is manifest,
although only one eye is used. But what in these cases makes
an enormous difference is the way the object is looked at. Thus
semi-transparent objects, with transmitted light, exhibit very
little solidity, while the same objects viewed by I'eflected light
appear moi-e solid with one eye than when seen in an ortho-
stereoscopic binocular by transmitted light with two eyes.
The light and shade which is secured by the employment of
reflected light and lost with transmitted light is the cause of
this heightened effect.

A curious instance of stereoscopic effect with a single picture

* "R. M. S. Journal,'* 1881, p. 209.

E. M, NELSON ON BINOCULARS.

55

Fi^.S.

may be often seen when a photograph is projected by a lantern
on a screen. I have frequently noticed the boughs of trees
apparently stretching out of the screen into the room.

But to return. It is pretty obvious that if we place precisely
similar images in each tube we cannot obtain the same kind of
stereoscopism as when dissimilar images are presented. We
nevertheless get a kind of stereoscopism which may be called a
bastard stereoscopism ; this can be seen in both the Abbe and
Powell binoculars when the whole of the eye-spots are used.
This bastard stereoscopism may also be repro-
duced in a single body by placing a stop over
the back of the objective with two lateral aper-
tures in it like Fig. 5. In passing I would
recommend all who take an interest in the
optical side of the microscope to provide them-
selves with a nose-piece adapter with a
slit in each side of it (Fig. 6). It is useful
for so many experiments, as it allows a
strip of paper with apertures or stops cut
in it to be placed over the back of the
objective. For lens testing also it is un-
equalled, as the paper strip in passing
through the slit causes no vibration. It can be used in con-
junction with my rotary nose-piece.* In lens testing a full cone
of light from the condenser should be used. It is important to
understand the principle of stereoscopic pictures as seen with
an ordinary stereoscope. Taking geometrical figures the two
truncated square pyramids are
suitable and well-known ex-
amples (Fig. 7). These very
dissimilar pictures combine
most perfectly in a common
stereoscope, and yield "ortho-"
or "pseudo- " stereoscopic effects
according to the way they are
between them perpendicularly
the ortho-stereoscopic image may be observed without instru-
mental aid ; the pseudo-stereoscopic image can also be seen by
viewing them through a square hole in a piece of card held

placed,
to the

By holding a card
plane of the paper

* " Q. M. C. Journal," Vol. ii. (1885), p. 153 ; " E. M. " (1885), No. 1,042.

.^6 fi. M. NELSON ON BINOCULARS.

parallel to this page, and in such a manner that the left eye can
only see the riglit-hand picture and the right eye the left-hand
picture.

Now are these figures " pei'spective " drawings, or are they
" parallactic displacements " ? They are called perspective
drawings, but in reality they are only parallactically displaced.
There is no foreshortening, the base is a square, and the top is
a square displaced to one side, and lines ruled joining the
corners. If you consider the centre of the truncated pyramid,
the focal plane, the base is parallactically displaced one way, and
the truncated top the other.

These drawings, which are exact copies of those given in the
text-books (originally French), are exaggerated representations
of the images seen by each eye. A cube illustrates the same
effect, and it matters not whether you draw it in true perspec-
tive, the edges of the side of the cnl)e beino- portions of Hues
drawn to the vanishing
point (Fig. 8), or draw it
parallactically displaced
with the edges of the side
of the cube parallel to
one another (Fig. 9). If the drawings of the cubes are exag-
gerated to anything like the same extent as those of the
truncated pyramid they will not coalesce ; the resultant picture
will be merely a super-position of two dissimilar cubes. It is
the latei'al displacement which is the sole and important point,
and it makes no difference whether that is obtained by true per-
spective or by parallactic displacement, because the eye cannot
distinguish between them, the displacement at its greatest being
only 8°, perspective foreshortening is impossible.*

With regard to microscopical stereoscopism, if the image of a
plane object, such as ruled squares, suffered perspective fore-
shortening by reason of aperture, different zones of the objec-
tive would yield different images, and the resultant picture
would be confused. Therefore it goes without saying that a
microscope image of even such an elementary object would be
simply an impossibility. This Prof. Abbe ably points out.

But with regard to depth, the depth of vision is so minute

* Perspective foreshortening is as cos 9 : 1 ; therefore for 8'^ it would
be in the proportion of 99 to 100.

E. M, NELSON ON BINOCULARS. 57

that the difference between " perspective " and " parallactic dis-
placement " becomes infinitely small and altogether quite imper-
ceptible to the eye. However keen in detecting errors of per-
spective an artist's eye might be, he would not be able in a thin
object to distingnish between "parallactic displacement" and
" perspective " with only 8° of displacement, in spite of the
methods of drawing being so widely different. Now Prof.
Abbe is perfectly right in saying that there can be no such a
thing as perspective in the microscope image, and that the
difference between the images seen with the right and left half
of the objective is caused by parallactic displacement. The
difference is, however, only one of name, because we must
remember that the depth of vision in the microscope is very
small (smaller than is allowed by Abbe) ; therefore, however
thick the object may be, the thickness you can see does not
amount to much, and no one could possibly distinguish between
such images, whether drawn in perspective or in parallactic
displacement (see dotted lines, Figs. 8 and 9).

Carpenter, it is true, uses the words " perspective projection ''
loosely.* He calls the pictures of the truncated pyramids
" perspective projections " when they are nothing of the kind,
and he uses it in the same loose way in dealing with the micro-
scopical image.

The truncated pyramids, of course, ought to be " perspective
projections " whereas they are drawn by " parallactic displace-
ment," and the microscope image is a "parallactic displace-
ment," though Carpenter calls it a "perspective projection."
Abbe, on the other hand, unduly accentuates the difference
between the microscopic and macroscopic images, so that a
wholly false impression is conveyed by his paper. After
rhetorical statements such as " the microscope image is a thing
sui generis;" "peculiar property of microscopic vision is in
strong contrast to the method of ordinary vision;" "elements
of an object are no longer depicted as solid objects seen by the
naked eye ; " "an essential geometrical difference between

* The words " perspective projection " occur in Carpenter's (5tli edition,
1875) article " Stereoscopic Binocular," pp. 57-73) six times in connection
■v\ith ordinary vision, and once with microscopic vision. The sole passage in
connection with microscopic vision is " pictures .... sufficiently dissimilar
in their perspective projections to give when combined in the microscope a
suflBcient but unexaggerated stereoscopic relief."

58 E. M. NELSON ON BINOCULARS.

vision with the binocular microscope and vision with the anaided
eye ; " " notwithstanding this difference the activities of the
brain and mind blend the images so as to give rise to sensations
of solidity, depth, and perspective ; " "the brain arranges them
so that the characteristics of solid vision are still presented,"
what wonder that the microscopical binocular images are held
to be so entirely dissimilar to any ordinary images that it is by
brain power alone that they can be turned to any account.

The truth is that there is no more brain effort required in the
examination of binocular objects than there is in recognizing
the similarity between two objective boxes which have been
made true to one another to yi^ inch. A considerable amount
of brain effort would, on the other hand, be necessary to dis-
cover their dissimilarity. Let us suppose that the two objective
boxes accurately turned with the yi--^ inch of difference are
before us on this table, and that I was to tell this Society that
" notwithstanding this difference the activities of the brain and
mind blend the images so as to give rise to sensations of ' simi-
larity ; ' " and again, that " the brain arranges them so that the
characteristics of (similarity) are still presented," although
these statements are rigidly true, I think you would be justified
in denouncing them as high-flown rhetorical nonsense.

The difference between the laterally displaced images of the
microscope and the perspectively projected images of ordinary
vision is practically nil (see Figs. 8 and 9, dotted lines), and
therefore no more brain effort or activity is required in viewing
binocular microscope images than in viewing ordinary objects.
It is aperture and focal depth that cause the parallactic displace-
ment. If a lens has insufficient aperture the stereoscopic effect
will be weak, and on the other hand if the aperture is too great
there will be hyperstereoscopism. Thus there is practically no
stereoscopic effect with a three-inch objective of 10° of aperture.

Stereoscopism may be said to begin with a two inch of 15° in
an ordinary binocalar ; at the same time it should be re-
membered that excellent stereoscopic effects can be obtained by
the Cherubin d'Orleans method and three-inch objectives, but
in this case we have the axes of the lenses inclined to the
object, and on that account true perspective pictures, whereas
a semi-aperature of 5° gives no scope for sufficient lateral dis-
placement.

E. M. NELSON ON BrNOCULARS.

59

Depth is an all-important element. There can be neither
displacement nor stereoscopism in either ordinary or micro-
scopic vision without depth. In this department of microscopy
there is any amount of room for theorizing. For instance, we
know that depth is reduced in the direct ratio of the increase of
aperture and in a greater ratio of that of power. Therefore
we might reasonably conclude that because stereoscopism
is a function of depth it might be greatly reduced by an increase
of power. Practically, however, such is not the case, for if you
change from a two-inch to a one-inch eye-piece, you will have
about a quarter of the depth, but the stereoscopism will remain
constant. Again, because parallactic displacement increases
with aperture, and because it is found that too great an aper-
ture in a low power gives an hyperstereoscopic effect on opaque
objects with reflected light, we might, therefore, conclude with
Dr. Carpenter that there is a limit of aperture for perfect
stereoscopism ; in practice, however, we do not find any such
limit. I have profitably used an oil immersion | of 1*4 N.A.,
but I do find that increase of power and aperture materially
degrade the quality of the image by accentuating the disturbing
effect of the prism. This points the moral — the fewer prisms
and the fewer surfaces the better. It is obvious, too, that the
division of the back of the objective by the prism also divides
the spectra, so that with a central axial cone
and a stop (Fig. 4) over the back of the objec-
tive we obtain an arrangement as in Fig. 11,
consisting of half a dioptric beam and four
spectra (three of the first order and one of the
second) unsymmetrically arranged with re-
gard to that beam ; but if we use duplex
illumination * by means of a stop (Fig. 12) at
the back of the condenser v/e secure a much
better arrangement, viz., a whole dioptric beam
and four symmetrically placed first order spectra
as in (Fig. 13). The stop at the back of the
lens is an advantage, because it keeps the

Jiy.l2.

* Duplex illumiuatiou by means of mirrors was first introduced by Eiddel,
Stei)henson used a condenser composed of cylindrical lenses and a double
stop as in Pig. 12. I do not discover any advantage to be gained by the
use of cylindrical lenses, and prefer the ordinary achromatic condenser.

60 E. M. NELSON ON BINOCULARS.

resolutiou in a vertical direction equal to that
in a horizontal direction.

The method and kind of illumination make
an enormous difference with the stereoscopic
binocular. Speaking generally reflected light
by lieberkuhn or side reflector and dark ground
illumination with an achromatic condenser and a stop yield
excellent results. In this latter case I prefer not to use a
bull's-eye.

Interesting experiments may be performed by passing a strip
of paper with a hole in it across the back of the objective
through the slotted nose-piece (Fig. 6) ; a somewhat deep ob-
ject should be on the stage, and a monocular body used. By
drawing the hole from the centre of the objective to its
periphery, the lense being carefully focussed on a middle plane
of the object, the upper part of the object within the focus is
displaced one way and the lower part beyond the focus is dis-
placed the other way. Bastard stereoscopisra may be seen in a
monocular by making two holes in the paper strip, so that two
marginal pencils alone are passed (Fig. 5). If, with a stereo-
scopic binocular and a lens of 80°, a similar stop be used hyper-
stereoscopism will be the result, but if the two holes be brought
to the centre there will be hardly any stereoscopic effect, the
best results being obtained when a stop as in Fig. 4 is used.

The position subsequently taken up by Carpenter in connec-
tion with the binocular microscope is very strange. In his
writings on the subject, prior to the publication of Prof. Abbe's
papers, we find a lucid and accurate (excepting only the loose
use of the word perspective) explanation of the phenomena,
but when he criticized the Abbe eye-piece * at the R. M. S. he
contradicted all his former writings by saying that it was not.
an orthostereoscope, notwithstanding that the conditions were
precisely the same as in the case of Wenham's and Nachet's I.
and II. (see Table). The only explanation I can suggest is
that he did not trace the path of the rays, and in consequence
he failed to perceive that a cross-over had been effected by the
eye caps.

Prof. Abbe has rightly pointed out in another paper f that

* " Journal R. M. S.," 1880, p. 1088.
t "Journal R. M. S./' 1884, p. 26.

E. M. NELSON ON BINOCULARS. 61

*' there is no true perspective difference of the images by
different portions of the apertures, because the microscopic
image does not admit of a perspective shortening of the lines,
which are oblique to the direction of the delineating pencils."
We must remember, however, that there is a difference in the
amount of lateral displacement of the images by different por-
tions of the apertures, and also that the difference between
lateral or parallactic displacement and perspective projection is
wholly unrecognizable in the microscope. Prof. Abbe has done
excellent service in combatting the absurd idea of " all round
vision." Who the author of " all round vision " was, I know
not, but I do not think that theory can be fastened on the late
Dr. Carpenter. It is true that he uses the word perspective in
connection with the microscope image, but just before he used
it in the same careless and incorrect manner when speaking of
microscopic pictures. It seems to me after careful study of his
article * that he did not intend the word perspective to carry
with it the conception of an all round vision.

Finally his theory with regard to the 40*^ limit of aperture for
perfect stereoscopic effects cannot be maintained, because the
very slight depth of the microscope image requires a large
amount of lateral displacement. I hold that when a certain
stereoscopic effect has been obtained with a lens of a certain
aperture, if the power be increased by means of a deeper eye-
piece, the stereoscopism will remain unaltered, because the
lateral displacement is magnified equally with the object. Thus
if a series of spheres diminishing in size were examined with a
certain lens under varying powers, whatever might be the
character of the stereoscopism of one of the larger spheres with
a low power, i.e., whether the effect was under, sufficient or
hyper-stereoscopic, a smaller sphere under a higher power
would exhibit the same degree of stereoscopism, the illumina-
tion remaining the same in both cases.

The best stereoscopic effects are obtained when a stop
(Fig. 4) is used at the back of the objective and duplex illumina-
tion employed. Great caution is necessary, so that the effect
shall be sufficient, and neither over nor underdone. The best
plan when the lens has been selected is to try various card-
board stops, and when the proper size is found, have them made

* Carpenter, 5th Edition, 1875, p. 70.

62 E. M. NELSON ON BINOCULARS.

in metal. Note, hyperstereoscopism can be easily produced by
the use of a too large stop at the back of the condenser for dark
ground illumination; this, therefore, should be carefully
avoided.

In conclusion it must be remembered that duplex illumina-
tion alters the conditions, and, to a certain extent, upsets the
rigid theory, because an axial pencil is sent excentrically through
each half of the lens (Fig. 13).

Explanation of some op the Figures.

Fig. 4. — A stop to be placed at the back of the objective.
A separate one is required for each lens.

,, 12. — A stop to be placed at the back of the condenser.
A special one is required for each objective.

„ 11. — The white dots show the spectra, the ring in the
centre represents the dioptric beam.

„ 13. — The rings in the centre of each circle represent the
dioptric beams. The white dots are spectra.

,, 7. — Parallactic drawings of two truncated square pyra-
mids, the displacement is greatly exaggerated.

,, 8. — A square parallelopiped drawn in perspective.

,, 9. — The same drawn by parallactic displacement.

,, 10. — Illustrates orthostereoscopism by Dr. Mercer's
method. The dotted lines denote the eye-spots
or Ramsden's circles. The figure shows that
when the tubes are racked in the eye-spots are
brought closer together, so that the outer portions
of the eye-spots pass through the inner portions
of the pupils. In opposition to this Abbe and
the editorial staff at the R. M. S. state that
orthostereoscopism is due to the employment of
the outer halves of the pupils. The cause of
orthostereoscopism in Dr. Mercer's experiment
as well as in the Abbe eye-piece is due to the
fact that the suppression of portions of the eye-
spots effects a " cross-over."

63

Some ISTew Records of British Cladocera.

By D. J. SCOURFIELD.
(Read May 20tTi, 1892.)

Plates IV. and V.

During the last three years I have repeatedly found a few
species of Cladocera which, although fairly well known on the
Continent and even in some cases in America, do not seem to
have been hitherto recognized as British. I am well aware that
it would not be wise to insist very strongly on this point in
regard to every one of these species, as there certainly do exist
some indirect references, in Baird's classic work on the British
Entomostraca, to forms very similar to, if not identical with,
two of those described below. These references can, however,
scarcely be looked upon as definite records, and consequently
have but little bearing upon the title of this paper. Moreover,
in each of the uncertain cases I have also seen the male.

As further introduction appears to be unnecessary in such a
case as this, I will at once proceed with a short description of
the species referred to, numbering six in all.

Ceriodaphnia megops, G. O. Sars (Plate IV, Figs. 1-3). —
This is a very fine species, and may be easily recognized, as it
departs rather widely from the normal type of the genus. The
striated shell of the female, and the greatly elongated antennules
of the male, distinguish it at once from all its allies, with the
exception, perhaps, of a doubtfully distinct form, C. cristata,
described in America by Prof. Birge.

Female. — Transparent, sometimes with a tinge of pink. Large
antennae, always more or less pink. Head prominent ventrally,
with only a very shallow bay anteriorly, and a slight angulation
in front of the antennules. Shell rather long and somewhat
rectangular, the dorsal and posterior margins meeting in a
blunt angle. Markings consisting of faint transverse strise, very

64 l>. J. SCOURFIELD ON BRITISH CLADOCERA.

similar to those of the common Simocephalus vetulus. The
strise occasionally coalesce, thus enclosing long lenticular areas.
On the ventral margin they merge into an irregularly hexagonal
reticulation. Tail obliquely truncate at its extremity, and pro-
vided with a double series of spines on each side of the anus.
Anterior to the latter is also a median line of little curved
thorns, diminishing in size forwards. The outer or principal of
the two anal rows consists of from seven to nine spines, the
longer or posterior ones being nearly straight and sharp as
needles. The inner row comprises a larger number of smaller
spines, but it can only be seen with some difficulty between the
large spines of the outer row. The two terminal tail claws are
rather slender, with a lateral line of fine hairs, but are without
accessory teeth. There are two dorsal spurs on the abdomen,
the posterior being only about a quarter of the length of the
anterior. The number of eggs carried at one time in the brood
chamber is often numerous, sometimes as many as ten. Ephip-
pium with one egg. Length ^'g^in.

The following are the places where I have so far found it : —
Wanstead Park, Essex, August and September, 1889, May to
October, 1890, August and September, 1891 ; Ditch at Horning
Ferry, Norfolk, August, 1890 ; Golding's Hill Ponds, Loughton,
Essex, August, 1891.

Male. — My specimens were reddish all over, and could be
easily distinguished from the female by their colour, even with
the naked eye. The head is more erect than in the female, and
more deeply bayed on the top. Dorsal margin of the shell very
nearly straight, with the blunt angle minutely spined. The
shell markings are peculiar. At the ventral margin they consist
of irregular hexagons as in the female, but across the middle of
the valves they are somewhat diamond-shaped, intermediate, in
fact, between true hexagons and the long striee characteristic of
the female. The tail is almost identical in shape and armature
with that of the female. The antennules and first pair of feet
are, however, very different. The former are much elongated,
and apparently two-jointed. The lateral seta is near the middle
of the long joint, which also bears at its tip the usual bunch of
sensory hairs and a long flagellum. This flagellum, which is
about the same length as the antennule, is slightly bent towards
the body in the middle of its length, and terminates in a small

D. J. SCOUEFIELD ON BRITISH CLADOCERA. 65

curved expansion. The first foot is provided witli a strong
hook, and a long filament very closely resembling the flagellum
of the antennule. Length -j'^^in.

The only examples I have seen were taken at Wanstead Park,
Essex, September, 1891. They exceeded the females in num-
ber in that gathering, and all the latter carried ephippia.

It seems very probable that Baird found this form, although
including it with G. reticulata, for in the "Natural History of
the British Entomostraca " there is a drawing of a so-called
Daphnia reticulata (Tab. vii.. Fig. 5), having the shell striae, and
even the general outline of the present species. Nothing,
however, is said in the text about a D. reticulata with striated
valves. The description of D. reticulata only states that " the
surface is covered with a complete meshwork of small
hexagonal cells."

Oeriodaphnia quadrangula, 0. F. Miiller (Plate lY, Figs.
4-7). — The form here referred to 0. F. Miiller's Daphnia quad-
rangula, is a much smaller species than the foregoing, and not
nearly so readily distinguished. It closely resembles a small
0. reticulata, but its shell-sculpture is fainter, while the tail-
claws are without the accessory teeth, so well marked in that
species.

Female. — Very light straw-coloured or more rarely slightly
red. Head with a distinct bay anteriorly, and a moderate angu-
lation in front of the antennules. Fornices covering the bases
of the large antennse rather prominent, with or without a little
spine at their extreme lateral extension. Cervical groove deep.
Dorsal margin of shell well arched, with a rather sharp angle
posteriorly. Shell-markings nearly regular hexagons, distinct,
but not very strong compared with some other species of the
genus. Tail slightly tapering towards the extremity, which is
rounded dorsally. Terminal claws without accessory teeth.
The anal spines, numbering about ten, are stout and recurved.
Just anterior to the anus, and on a level with the smaller anal
spines, are two rows of three or four long and slender setae
closely approximated to the middle line of the tail. This
feature seems constant in all the specimens I have examined, but
I have not seen it referred to by previous authors. The brood
chamber is closed by one abdominal spur, which is followed by

JouRN. Q. M. C, Series II., No. 31. 5

66 D. T. SCOUHFIKLP ON HRITISH CLAOOCERA.

two very much smaller projections. The number of eggs is
generally four. Epliippium witli one egg. Length ^\ in.

My notes of its occurrence are as follows : — Wanstead Park,
Essex, May to November, 1890, March to November, 1891,
April, 1892 ; Filby Broad, Middle Dyke, and Ditch at Wrox-
ham, Norfolk, August, 1890 ; Higham Park, Woodford, Essex,
May and August, 1891 ; Eagle Pond, Snarcsbrook, Essex,
October, 1891 ; Royal Botanic Gardens, Regent's Park, London,
April, 1892 ; Gelding's Hill Ponds, Loughton, Essex, April, 1892.

Male. — Colour same as female. Head large, dorsal and
ventral margins of the shell nearly straight. Shell markings
as in the female. Antennules but little enlarged, with a
flagellum barely twice as long as the terminal tuft of sensory
hairs. First feet with a hook and a long filament. Tail
practically the same as in the female. Length -^^ in.

Wanstead Park, Essex, September and October, 1891.

The form figured by Baird as D. reticulata, var. quadrangula,
may have been the ephippial female of the present species,
but the details given are scarc^ely sufficient to make the refer-
ence even moderately certain.

Daphnia HVALiNA, Lcydig (Plate V, Fig. 1). — This is one of
the group of species of the genus Daphnia, which delight in
the clear water of ponds and lakes free from weeds. It comes
rather close to some of the varieties of D. lougispina, but is
more transparent, has a taller head, and fewer anal spines.

Female. — Hyaline. Head rounded, and nearly one- third the
whole body length, but not much crested. Its ventral margin
is decidedly concave. Shell-spine very long, often one-half the
length of the animal. Shell markings rhomboidal. Compound
eye with prominent lenses arranged regularly around the
nearly black mass of pigment. Simple eye with a small spot
of dark pigment. Tail armed with from eight to ten anal
spines. Terminal claws smooth, i.e., without accessory teeth
Large specimens may sometimes be seen carrying from ten to
twelve eggs, or even more, but they are usually less numerous
than this. I have not observed the ephippial female. Length
Y^^ in; without shell-spine. Specimens from the Eagle Pond,
Snaresbrook, are usually less than this, however, while those
from Connaught Water, Cliingford, are occasionally more, even
reaching -jy^"-

D. J. SCOURPIELD ON imiTISIl CLADOCERA. 67

I have taken it as follows : — Connaught Water, Chingford,
Essex, September, 1890 and 1891 ; Eagle Pond, Snaresbrook,
Essex, November, 1890, and October, 1891 ; " Green Man "
Pond, Leytonstone, Essex, November, 1891 ; Wanstead Park,
Essex, April, 1892.

The male has not yet been seen.

Dai'hnia (lAi-EATA, G. 0. Sars (Plate V, Figs. 2 and .S.).— This
is similar in most respects to the preceding, and is, like it,
fomid only in clear water. It diii'ers chiefly in its smaller size,
and slightly taller and distinctly pointed head. There can bo
little donbt that it is the D. ijalcata of Sars, although its claim
to specific rank seems uncertain.

Female. — Hyaline. Head well crested, one-third as long as
the animal, more or less sharply pointed, with a nearly straight
or slightly concave ventral margin. Shell-spine long, quite
one-third total body length. Shell-markings rhomboidal as
usual in this genus. Lenses of the compound eye distinct and
regularly arranged. Simple eye with a pigment spot. Tail
with seven to nine small anal spines. Terminal claws smooth.
Summer eggs usually few. Ephippium with two eggs.
Length, ^'^^in. without shell-spine.

Wanstead Park, Essex, September, 1890, August to Novem-
ber, 1891.

Male. — Head more sliarj)!}' pointed than that of the female,
body more rectangular, shell-spine nearer dorsal margin and
pointing obliquely upwards. Antennules enlarged (compared
with female) and movable. Each witli a minute lateral seta
near tip, and a terminal flagellum in addition to the usual tuft
of sense hairs. Flagellum short, not exceeding the sense hairs
in length. First feet with a hook and a long filament, which
seems to be minutely setose near the free end. Length, r^^ in.
without shell- spine.

Wanstead Park, Essex, September and October, 1891.

Alona intermedia, G. O. Sars (Plate V, Figs. 4 and 5). — I
have usually found this species either in dense masses of algre
floating in clear water, or else in shallow ponds thickly grown
with aquatic plants. It is one of the smaller forms of the
genus, and might be mistaken for A. guttata, from which it
differs mainly in the shape and armature of the tail.

68 D. J. seOURPIELD ON BRITISH CLADOCERA.

Female. — Yellow or yellowish brown. Dorsal margin of
carapace well arched, meeting posterior at a very obtuse angle.
Ventral margin nearly straight, fringed with hairs, and
rounded behind. Shell marked with faint longitudinal ridges.
Simple eye about half the size of the compound, and slightly
nearer to it than to the tip of the rostrum. Antennae small.
Tail short and rounded at the end. Furnished on each side of
the dorsal edge with a row of minute spines in groups of three
or four. There is also a lateral row of teeth, but they are very
faint. Terminal claws with a small spine at the base. Eggs
usually two. Length, -^^ in.

Found in the following localities : — Wanstead Park, Essex,
November, 1889, September, 1890, October, 1891 ; Cuckoo Pits,
Chingford, Essex, September, 1890; Victoria Park, London,
November, 1890 ; Eagle Pond, Snaresbrook, Essex, November,
1890 and 1891.

So far, I have not seen the male.

Chydorus ova lis, Kurz. (Plate V, Figs. 6 and 7). — The
genus Chydorus comprises some nine or ten recognized species,
of which one, G. sphericusj is extremely abundant everywhere,
while the remaining forms are rare and local. The former
consequently is well known, while the latter are very little
known, and probably often confounded with the common
species. There can be little doubt that this has often happened
in the case of the present species. It may be distinguished,
however, from C. sphericus by the absence of evident reticula-
tion on its more evenly ovoid shell, and by its somewhat
broader tail.

Female. — Colour red. Shell oval or somewhat egg-shaped,
not truncate posteriorly, nor angulated ventrally. Shell
markings hexagonal, but so extremely ill-defined as to be
easily overlooked. Eye-spot nearer to the compound eye than
to the end of the rostrum, a little more than half the size of
the former. Antennules spindle-shaped, with a lateral seta
near the middle, and a couple of sense hairs just anterior to the
terminal banch. Tail rather broad, with a prominent pre-anal
projection. It is rounded at the extremity and armed with
twelve or thirteen little teeth. Terminal claws with two
basal teeth, the anterior of which is ver}^ minute. Eggs two.

b. J. SCOUKFlELt) ON iiRlTISH CALDOCfcKA. 6^

Length, ^Y ill- Kurz * seems to have had rather smaller
examples, for he gives the length as 0*4 m.m. He also shows
the tail a little more tapering towards the end, and with fewer
spines, than was the case in my specimens, but these points of
difference seem scarcely sufficient to separate the two forms.

Eagle Pond, Snaresbrook, Essex, October, 1891. Sphagnum
Pool, Leyton Flats, Essex, November, 1891.

The male is still unknown, I believe.

Description of Plates.

IV.

Fig. 1. — Geriodaphnia megops. $ X 60.
» 2.— „ „ c^ X 60.

„ 3.— „ „ Tail of 5 X 150.

„ 4. — Geriodaphnia quadrangula. 5 x 90.
„ 5.— „ „ (^ X 90.

„ 6.— „ „ Tail of 9 X 180.

„ 7. — ,, „ Ditto (dorsal view to show

inner rows of pre- anal spines — diagrammatic.)

V.

Fig. 1. — Daphnia hyalina. Head of 2 x 65.
„ 2. — Daphnia galeata. 2 x 65.
)j 3. — „ „ (^ X 65.

„ 4. — Alona intermedia. $ x 110,
„ 5.— „ „ Tail of 2 X 250.

„ 6. — Ghydorus ovalis. 9 X 80.
„ 7.— „ „ Tail of 2 X 180.

* " Dodekas neuer Cladoceren," Sitzungberichte der kaiserlichen Ak. der
Wiss. — Math. Nat. classe, Band 70, Abth. 1. Vienna, 1874-5.

70

In Memoriam.

WALTER W. REEVES.

By Frederic Hy. Ward, M.R.C.S., F.R.M.S.

In a Club like ours, in which the social element is one of the
most distinctive features, it would not be meet to allow the
death of one of its original founders to pass by without remark.
To chronicle our loss becomes still more a dut}^ in the case of
our late friend Mr. Reeves, who from his punctual attendance
at all meetings, and constant readiness to assist in all matters
pertaining to the interests of the Club, might almost be looked
upon as its father, rather than one only of its original founders.

I could wish that the duty of recording his worth had been
committed to more com^Detent hands than mine, but I feel that
his name will remain to the last in the affectionate remembrance
of his friends and fellow-members, and that nothing can be said
or written by anyone which could make it more enduring.

Walter Waters Reeves, the eldest son of Thomas Watei-s
Reeves, was born on February I4th, 1819, at Beckley, in
Sussex, and was educated under Dr. Davies at the Cranbrook
Grammar School. While a schoolboy he showed his fondness
for natural history, and w^as continually collecting specimens.
Nothing delighted him more than rambling in the woods and
fields, and searching the banks and hedgerows for anything
that was alive. Returning home, he would triumphantly pro-
duce from his pockets his captures— not always, however, to an
admiring home circle when these consisted of snakes or other
creatures usually viewed with some repugnance. About this
time he made a very good collection of the eggs of British birds,
which he subsequently presented to a local museum. He was
by no means a collector merely. He carefully watched and
studied the birds and their habits at the different seasons, and
made himself familiar with their different notes and songs.
Down to a very late period he would identify any bird by a few

IN MEMOKIAM. 71

notes, or its mode of flight, where these are distinctive, and I
remember his complaining to me comparatively recently that
he thought his memory was failing, as he could not always tell
what birds he heard.

On his leaving school it was decided that he should enter
the medical profession, and with this object in view he was
articled to a surgeon at Maidstone, where he remained some
years. It was here that he commenced the study of botany, to
which he devoted most of his leisure time. He thought no
trouble too great to be taken in this his favourite pursuit, and
soon became acquainted with all the plants in the neighbour-
hood, often walking 20 miles or more before breakfast that
he might find some fresh specimen or obtain material for
examination at home. He speedily acquired a very good collec-
tion, with the assistance of some of the well known botanists of
that day, and on his leaving Maidstone his herbarium contained
specimens of almost every British plant, ferns as then classified
being particularly well represented. When his period of pupilage
expired he was not ambitious to advance himself in his profes-
sion by coming to London and entering on hospital work ; in
fact, the very idea of hospital practice or operative surgery
was repugnant" to him. To abandon natural history pursuits
was a sacrifice too great, and he went in preference to Farnham
as assistant to a surgeon, and afterwards to Tunbridge Wells in
the same capacity. I think it was about this time that he had
an attack of rheumatic iritis, which permanently injured the
sight of one eye, and after laying him by for a considerable
time led him to renounce the idea of qualifying for practice.

Almost as soon as photography became a practical art he
entered upon it with a good deal of zest, and was even in busi-
ness for a short time as a photographer. From some cause or
other it did not turn out to be very profitable, a.nd there is
little doubt that so far as the trade element was concerned he
was unfitted for it. By the wax paper process he secured
negatives of most of our native ferns, and at one time contem-
plated issuing a complete series of prints from them. He also,
by the same process, commenced a series of views of the parish
churches in the neighbourhood. Those who are acquainted
with the difficulties of this branch of photography would be
astonished at the merit which some of these negatives display.

72 IN MEMORIAM*

In 1864 Mr. llcevcs joined the Royal Microscopical Society, and
in 1868 he was made Assistant Secretary.

The appointment he held for 16 years, and on his resignation,
in consideration of his services, he was presented with the sum
of £100.

Members of the Qiiekett will remember with pleasure that
about this time they embraced the opportunity of his retiring
from office to present him with an illuminated address and a
purse of sovereigns in recognition not only of his services to
microscopy, but also of the esteem in which he was held. This
was always a source of great gratification to him, and the
address henceforth held a prominent position in his room above
the table devoted to microscopic appliances.

It would be unnecessary to detail here the services he rendered
to our Club as a Member of the General and Excursion Com-
mittees. Virtually he was the leader of the excursions and
botanical referee, and so long as the annual dinner was held
at Leatherhead he was the principal organizer of the day's
proceedings. At the ordinary meetings of the Club he was
perhaps the most constant attender, and the register would
show that the nights on which he was absent were very, very
few.

Towards the close of last year his health began to fail, and
his friends noticed an unusual pallor in his face and a gradual
loss of flesh. He had complained of rheumatic pains at times
for many years, but they were never so bad as to confine him to
the house. The first sj^mptoms of his malady — cancer of the
stomach — were sickness with diarrhoea, which kept him to his
rooms for nearly a week. He would not admit it was anything
more than a bilious attack, but after it had recurred several
times, and he had on each occasion vomited much blood, he
acknowledged that he was failing, and said he wanted some-
one to nurse him. With this object in view he left London on
30th January, and went to reside with his sister at Middleton
Vicarage, taking with him his two pet dormice, which had been
his companions for some time. He did not at first appear to
have suffered from the journey, but a day or two after his
arrival he got worse, and on February 5th he . had frequent
vomiting of blood. In a few days he rallied, and was able to
sit up a little in his bedroom each day, was in his usual good

IN MEMOKIAM. 73

spirits, and frequently talked of the plans lie had formed of
returning to London to superintend the packing of his treasures
and of paying a round of final visits to his friends, before
settling down for the remainder of his life in that little York-
shire village.

On the 24th, however, the same distressing symptoms
returned; he became very weak, and it was with great
difficulty he could be coaxed into taking any nourishment. In
a few days, with the cessation of the sickness, he again im-
proved, and his spirits revived, but he appeared unable to
recover the ground he had lost ; for seven or eight hours in the
day he would sit up in his bedroom, but was unable to get
downstairs. On March 15th he went out into the garden, only
remaining a few minutes, and he was glad to return within
doors. Shortly after he was seized with acute pain in the
stomach, and was helped to bed. On the following day all the
worst symptoms returned, and again on the 22nd, lasting each
time for two or three days. On the 29th he confessed that he
felt more ill than he had ever done before ; for a day or two
was in a very prostrate condition, quite unable to sit up in bed,
and took very little interest in anything. Shortly after this
he rallied, and from that time had no further return of the
sickness. Towards the end of April he was much better, and
it was arranged that his niece, who had been nursing him most
assiduously, should come up to London, and superintend the
packing of his herbarium, books, etc., and he gave special
instructions that one of his botanical presses should be sent off
at once, as he was contemplating pressing some plants. On
the last day of the month all his belongings arrived safely, and
he was relieved of the anxiety he had felt, lest any of his
apparatus, slides, books, or plants should be injured in the
transit. At this time I received two letters written to his
dictation, but signed by himself, though the contents were
quite in his old style, cheerful and, of course, botanical, when
I saw his signature I felt that there was great cause for alarm.
But when I heard on May 9th that he was in good spirits and
had been visited by some old friends, to whom he had been
s-howing plants and slides, and quite with his old fervour, that
he had had no return of the bad symptoms, 1 began to hope
that, as the weather got warmer, he might gain strength and

74 '■ IN MEMORIAM.

be able once more to get out into the country that he loved, but
it was not to be.

Early on the morning of the 16th he became suddenly worse,
had acute pain, and was almost collapsed. He obtained relief
from the remedies used, and had some hours' sound sleep, but
the weakness increased, there appeared to be no power to rally,
and at 6 p.m. on the next day he began to sink. Propped up
in bed, he retained his consciousness, and at 11 p.m. wished his
niece good-night for the last time, then, slowly and calmly
sinking, passed away without a sigh or a single struggle, in his
sister's presence, at 3.30 the next morning. On the following
Saturday his mortal remains were laid to rest in the little
churchyard by his brother-in-law, the Yicar of Middleton.

And now to say the last words. Mr. Heeves was of a modest
and retiring disposition ; his voice was very rarely heard in
public, though there were very few subjects that came before
our meetings on which he could not have said something. He
had a good, all-round knowledge of matters connected with the
microscope, but, owing to his limited sight, he did not work
much with that instrument. He was, before all things, a
botanist — one of the old type of field botanists — and could at
once, almost invariably, give the name to any plant he might
meet with in his rambles, and nothing gave him greater
joleasure than to see them growing in their native habitats.
For over twelve years, and for some thousands of miles, I have
accompanied and collected with him, and it was indeed a rare
occurrence if he did not find the things he went in search of*
The most marked trait in his character was gentleness ; few
could have fewer enemies or more friends. His fellow members
will not readily forget his kindly features and his genial smile.
The place he has left vacant in our Club will remain vacant—
our friend will return no more.

75

Q.M.C. EXCURSIONS, 1890.
March 29th.

List of Objects Found on the Excursion to the Gtardens of
THE Royal Botanic Society of London, by Messrs E. T.
Browne, Burton, Parsons, Rousselet, and Scourfield.

PROTOZOA.

Acineta mystacina.

„ tuherosa.
Dinohryon sertularia.
Epistylis anastatica.
,, flavicans.
,, plicatilis.
Ojpercularia nutans.
Podophrya mollis.

„ elougata.

Stentor polymorphus.

,, Bceselii.
Vorticella campanula.
„ longifilum.

„ m^icrostoma.
,, nutans.
VEBMES. Rotifera.
Anurota aculeata.

,, cochlearis.
Asplanchna Brightwellii.

„ priodonta.

Brachionus angularis,
,, pala,

„ quadratus.

„ ruhens,

,, urceolaris.

Bistyla flexilis.
Euchlanis deflexa.

Floscularia campanulafa.
Limnias ceratophylli.
Melicerta ringens.
Notholca scapha.
CEcistes crystalUnus.
Polyarthra platyptera.
Rotifer macrurus.

,, vulgaris.
Synchceta pectinata.

,, trcmula.
Triarthra hngiseta.
CRUSTACEJ!]. Entomos-
traca.
Aloua quadrangiilaris.
Bosmina longirostris.
Candona Candida.
,, fahceformis.
„ pubescens.
Canthocamptus minutus.
Ghydorus sphfpricus.
Cyclops pulchellus.

,, Scourfieldii.

,, serrulatus.

,, tenuicornis.

„ viridis.
Gypria opthalmica.

„ Serena.
Cypridopsis vidua.

?6

Diaptomus ? gracilis. Simocejphalus vetulus.

Ilyocryptus sordidus. MOLLUSGOIDA. Polyzoa.
Leydigia acanthocercoides, Fredericella sultana.

Fleuroxus trigonellus. Faludicella Ehrenhergii.

Attendance : Twenty-six members of the Club, seventeen
members of other Societies, and twelve visitors. Total, 55.

April 12th.

Objects Found on the Excursion to Snaeesbkook, by Messrs.
Parsons, Rousselet, and Western.

PBOTOZOA. Floscularia coronetta.

Coiidylostoma stagnale. Limnias ceratophylli.

Finohryon sertularia. Mastigocerca hicornis.

Nassula ornata. Melicerta conifera.

Stentor polymorphus. Notholca scapha.

VERMES. Rotifera. Notops hrachionus.

Anurcea aculeata. „ hyptopus.

„ hrevispina. CEcistes crystallinus.

,, cochlearis. ,, inter 'tnedius.

,, serrulata. Folyarthra platyptera.

Asplanchna priodonta. Rhinops vitrea.

Brachio7ms angularis. Rotifer citrinus.

„ pala. Stephanoceros Eichhornii.

„ quadrata. SyncJiceta pectinata.

„ rubens. „ tremula.

„ urceolaris. Triarthra longiseta.

Copeus labiatus. MOLLUSGOIDA. Polyzoa.

Euchlanis pyriformis. Fredericella sultana.
„ triquetra.

Attendance: Eleven members of the Club, three members
of other Societies, and two visitors. Total, 16.

April 26th.

Objects Found on the Excursion to Hayes and Keston
Commons, by Mr. Rousselet.

PROTOZOA. ' Binobryon sertularia.

Amphileptus Jlagellatus VERMES. Rotifera.

(Rousselet), n.s. Anurcea aculeata.

Bidinium nasutum. „ hrevispina.

77

Anurcea cochlearis.
Asplanchna priodonta.
Brachionus angularis.

„ pala.

Polyarthra plafyptera.

vitrea.
Synchceta pectinata.
Triarthra longiseta.
MOLLUSCOIDA. Polyzoa..
Frederic ella sultana.

Attendance : Seven members of the Club.
May 10th.
Objects Found on the Excursion to Richmond Park.

PROTOZOA. Brachionus rtibens.

Dinohryo?i sertularia. Binocharis pocillum.

OpJiridium versatile. Floscularia cornuta.

Stentor niger. (Ecistes crystallinus.

„ polyviorpJiics. Polyarthra platyptera.

Trachelius ovum. Rotifer macroceros.

VERMES. Botipera. Stephanoceros Eichhornii.

Anurcea aculeata. Taphroca^npa annulosa.

,, cochlearis. Triarthra longiseta.

Attendance : Ten members of the Club, four members of
other Societies, and one visitor. Total, 15.

May 31st.

Objects Found on the Excursion to Staines, by Messrs.
Burton and Rousselet.

CRYPTOOAMIA. ALGJE.

Desmidiace^.

Closterium moniliferum.

Cosmarium crenatum.

Xanthidium fasciculatum.
PHANEROGAMIA.

TJtricularia vulgaris.
PROTOZOA.

Ceratium fusus.

Dinohryon sertularia.

Euplotes patella.

Stentor polymorphus.

Trachelius ovum.
VERMES. Rotifera.

Anurcea aculeata.
Attendance: Ten members of
other Societies, and three visitors.

Anurcea cochlearis.
Asplanchna priodonta.
Asplanchnopus myrmeleo.
Brachionus pala.
Euchlanis triquetra.
Mastigocerca rattus.
Monostyla lunaris.
■^Notommata aurita.
Polyarthra platyptera.
Proales parasita.
Rotifer vulgaris.
Salpina redunca.
Stephanoceros Eichhornii.
Taphrocampa annulosa.

the CJub, two members of
Total, 15.

78

June 14t]i.

Objects Found on the Excursion to Whitstable, by Mr.
Waddington.

POEIFEBA.

Grantia,
Leucosolenia.
GCELENTEBATA.

Hydro-

ZOA.

Cainpanularia.

Coryne pusilla.

Sertularia.

Tuhularia mdivisa.
AcTiNOZOA. Ctenophora.

Berlje, sp.

Pleurohrachia.
EGHINODEEMATA.

Ojphiocoma.

Ophiura.

Solaster papposa,
VERMES.

Cirratula.

Sahella.
CRUSTACEA.

Caprella.

Nymphon gracile.

Pagurus Bernhardus.

Pycnogonum.
MOLLUSCOIDA. Polyzoa.

Bowerhankia imbricata.

Eucratia chelata.

Crista.

Flustra.

Memhranipora.
Tunicata.

Atnaro^icium.

Botryllus

Clavellina.

Cynthia.

Perophora Listeri,

Attendance : Twelve members of the Club and three members
of other Societies. Total, 15.

June 28th.

Objects Found on the Excursion to Oxshott, by Messrs.
Chapman, Oak den, Parsons, and Western.

PBOTOZOA.

Dinohryon sertularia.
Stentor polymorphus, green
var.
VERMES. Rotifera.
AniLrcea hrevispina.

,, serrulata.

„ tecta.
CepJialosiphon limnias,
Conochilus volvox.
Copeus Cerberus,

„ pachyurus»

Binocharis tetractis.

Euchlanis triquetra.

Floscularia cornuta.

Furcularia longiseta.

Limnias rnyriopliylli (Wes-
tern = Limnioides r^iyrio-
phyllif Tatem).

Mastigocerca bicornis.
„ bicristata.

Melicerta conifera.

Notops brachionus.
„ hyptopus.

79

(Ecistes crystalUnus.
,, pilula.
,, umbella.
Polyarthra platyptera.
Rotifer macroceros.

,, vulgaris.
Salpina hrevispina.
„ mucro7iata.
Stephanops muticus.
„ unisetata.

Attendance : Eight members
of other Societies. Total, 12.

Synchceta pectinata.
Taphrocampa annulosa.
ARACHNIDA. Acarina.
Oribatidj].

Notaspis lacustris, adults
and nymphs.
Hydrachnid^.

Arrenurus candatus, <$

,, glohator

Hygrolates, sp.
of the Club and four members

July 12th.

Objects Found on the Excursion to Totteridge, by Messrs.
E. T. Browne, Burton, Parsons, and Western.

PROTOZOA.

Anthophysa vegetans.
Arcella aculeata.
Geratium fusus.
Coleps liirtus.
Condylostoma stagnale.
Difflugia aculeata.

,, globosa.

,, pyriformis.

,, urceolata.
Binohryon sertularia.
Euplotes patella.
Parameciiwi aurelia.
Stentor niger.

,, polymorpjJius.
Yaginicola crystallina.
VERMES. Rotifera.
Amtrma aculeata.

„ cochlearis.

,, tecta.
Bracliionus angularis.
„ Bakeri.

„ pala.

„ Tubens.

Crplopus porcellus.

Golurus hicuspidatus.
Dinocharis tetractis.
Eosphora aurita.
EucJilanis dilatata.
Floscularia campanulata.

„ cornuta.

„ ornata.

,, gracilis.

,, longiseta.

Limnias ceratophylli.
Mastigocerca hicornis.
,, carinata.

„ rattus.

„ stylata.

Melicerta ringens.
Monostyla cornuta.
Notommata aurita.
Notops hyptopus.
(Ecistes crystalUnus.
Philodina citrina.
Polyarthra platyptera.
Pompliolyx sulcata.
Rotifer tardus.
Sacculus viridis,
Salpina hrevispina.

80

Scaridium longicaudum.
Stephanoceros Eiclihornn.
Stephanops lamellaris.
Synchceta pectinata.

,, tremula.
Triarthra hreviseta.

,, longiseta.

Gastrotricha.

Dasydytes fusiformis,

TURBELLARIA,

Planaria lactea.
„ nigra.
ABACHNIDA. Acarina.
Limnochares aquaticus.

Attendance : Mne members of the Club and three members
of other Societies. Total, 12.

July 26th.

>
■' Objects Found on the Excursion to Guildford, by Messrs.

E. T. Browne, Chapman, Parsons, and Western.

POniFERA. VERMES. Rotifera.

Larval (planula), stage of a Dinops longipes, n.s.
spongilla. (Western).

Megalotrocha alho-flavicans.

Attendance : Eight members of the Club and two members of
the South London M. and N. H. Club. Total, 10.

August 30th.

Objects Found on the Excursion to Woking, by Messrs. E.
T. Browne, Chapman, Parsons, and Western.

PROTCZOA.

Difflugia p?'oteifor7nis.
Rhipidodendron Iluxleyi.
Stentor niger.
T'rachelius ovum.
Vorticella camp)anula.
VERMES. Rotifera.
Anurcea aculeata.

„ ? brevispina, var,,

with only one posterior

spine.
Cephalosiphon limnias.
Copeus pachyurus.
Dinocharis tetractis.
Ench la in's triqvetra.

Floscularia amhigua.

„ campamdata.

„ cornuta, var.,

with horn of extraordi-
nary length.
Floscularia coronetta.

,, longicaudata.

Fitrcularia longiseta.
Limnias ceratophylli .
Mastigocerca hicornis.
Melicerta conifera.
Microcodon claviis.
Monostyla lunaris.
(Ecistes Irachyatus.
„ crystallinus.

81

(Ecistes pihda.

„ umbella,
Philodina amleata.

„ macrostyla.
Polyartlira platyptera,
Pterodina patina.
Rotifer macroceros.

„ macrurus.
Stephanops unisetatus.
Syncha^ta pectinata.
Attendauce : Seven members
of the South London M. and N.

Taphrocampa annulosa.
ARAGHNIDA. Arctisco-

NIDiE.

Macrohiotus Hufelandii.
MOLLUSCOIDA. Polyzoa.
Cristatella mncedo.
Fredericella sultana.
Paludicella Ehrenhergii.
Plumatella repens.

of the Club, and three members
H. Club. Total. 10.

September 13th.

Objects Found on the Excursion to Chingford, by Messrs. E.
T. Browne, Oxley, Parsons, Scourfield, Spencer, and
Percy Thompson.

PROTOZOA.

Amceha proteus.
Amphileptus gigas.
Arcella vulgaris.
Centropyxis amleata.
Difflugia {=Trinema)

chelys.
Difflugia lobostoma.

„ pyriformis.

,, spiralis.

,, urceolata.
Dinohryon sertularia.
Halteria grandinella.
SticJwtricha aculeata.
Stylonichia mytilus.
Uro centrum turbo .

VERMES. ROTIFERA.

Anurcea serrulata.

„ tecta.
Brachionus BaTceri.
Cmlopus porcellus.

,, tenuior,
JouRN. Q. M. C., Series

Colurus bicuspidatus.

„ caudatus.
Conochilus volvox.
C opens caudatus.
,, pacbyurus.
en- Diaschiza exigua.
Diglena ? uncinata.
Dinocharis pocillum.
„ tetractis.

Diplois propatula,
Euchlanis dilatata.
„ triquetra.
Floscularia campamdata.

,, ornata.

Furcidaria forficula.
,, longiseta.
Mastigocerca bicornis.
„ carinatus.

„ rattus.

Melicerta ringens.
Metopidia oxy sternum.
Monostyla cornuta.

II., No 31

6

82

Xoteus quadricornis.
Notommata lacimdata.
Notops hrachionus.
CEcistes crystallinus.
Philodina megalotrocha.
Folyartlira plati/ptera.
Proales jmi'asita.

,, jyetromyzon.
Pterodina patina.
Rotifer macroceros.

„ vulgaris.
Sacculus viridis.
Salpina hrevispina.

„ mucronata.
Stephanops lamellaris.
Synchceta pectinata.

,, treiiiula.
Triphylns lacustris.
CR USTA CEA. Entomos-

TRACA.

Alona intermedia. New to

Britain.
Alona quadrangidaris.
Alonella excisa.
Bosmina longirostris .
Candona lac tea.

Canthocamptiis mimitus.
Ceriodaphnia reticulata.

,, rotunda.

Chydorus sphcericus.
Cyclops phaleratus.
,, serridatus.
„ signatus.
„ tenuicornis.
„ Thomasi. New to

Britain.
,, viridis.
Cypria serena.
Cypridopsis vidua.
Daplmia hyalina. New to

Britain.
Daphnia pulex.
Diaptomus ? gracilis.
Pleuroxus trigonellus.

,, truncatus.
Simocephalus vetidus.
INSECTA. DiPTERA.

Corethra plumicornis , Larva

of.
Limnobium replicatimi, Larva
of.

Attendance : Eleven members of the Club and three members
of other Societies. Total, 14.

September 27th.
Objects Found on the Excursion to Gunnersbury Park.
PROTOZOA.

Condylostoma stagnale.
Dinobryon sertularia.

VERMES. ROTIFERA.

AnurcBa hrevispina.

„ cochlearis.

„ . tecta.
Asplanchna Briylitwellii.

Brachionus angular is.

„ pa la.

,, rubens.

M astigocerca hicornis.
Polyarthra platyptera.
Sacculus, sp.
Synchceta pectinata.
tremula.

83

Trinrthra lonqiseta. Daphnia mucronata^

CRUSTACEA. Entomostraca.
Bosmina longirostris.

Attendance : Twelve members of tlie Club and tlireo members
of other Societies. Total, 15.

Q.M.C. EXCURSIONS, 1891.
April 11th.

List of Objects Found on the Excursion to the Gardens
OF THE Royal Botanic Society of London, by Messrs.
Grenfell, Parsons, Rousselet, and Scourfield.

PROTOZOA.

Antliophysa vegetans.
Archerina Boltoni.
Coleps hirtus.
Condylostoma stagnale.
Epistylis digitalis.
Euglena crypta (Grenfell),
n.s.

Halteria (apparently n.s.).
Opercularia nutans.
Stentor polymorphus .
Trachelius ovum.
And a very large proto-
myxon, the central part
measuring more than a
quarter of an inch across.
VERMES. Rotifera.
AnurcBa aculeata.
Asplanchna Brightwellii.
Brachionus angularis.
,, Bakeii.

„ pala.

,, ruhens.

Floscularia campanulata.
ornata.
tvilohata.

Limnias annulatus.

,, cevatophylli.

,, cornuella.
Monostyla lunaris.
CEcistes crystallinus.

J, intennedius.
stygis.
Polyarthra platyptera.
Pterodina patina.
Rotifer macrunis.
Stephanoceros Eichhornii.
Synchceta pectinata.
Taplirocampa annulosa.
Triarthra longiseta.
CRUSTACEA. Entomos-
traca.
Candona puhescens.
Canthocamptus minutus.
Chydorus sph^Ericus.
Cyclops plialeratus.

„ Scourfieldii.

,j serrulatus.

„ tenuicornis.

„ ThomaH.

„ vicinus.
Cypria opthalmica.

84

Cypria serena.
Cypridopsis vidua.
Ilyocryptus sordidus.
Simocephalus vetulus.

Attendance : Thirtj-seven members of the
members of other Societies, and eleven visitors.

ARACHNIDA. Arctisco-
Macrohiotus Hujelandii,

Club, seventeen
Total, 65.

April 25th.

Objects Found on the Excursion to Snaresbrook, by
Messrs. Parsons and Eousselet.

PROTOZOA.

Floscularia cornuta.

Acineta mystacina.

Furcularia longiseta .

Archer ina Boltoni.

„ sphcerica.

Bursaria truncatella.

Mastigocerca elongata.

Carchesium polypinum.

Meliceria conifera.

Dinobryon, sp.

Monostyla cornuta.

Litonotus fasciola.

Notops brachionus.

Pelomyxa, sp.

„ hyptopus.

Spirostomum amhiguum.

„ 7iii7ior (Rousselet),

Stentor niger.

n.s.

„ polymorphus, green

(Ecistes crystallinus.

var.

„ inte?medius.

VERMES. ROTIFERA.

Pompholyx sulcata.

Anurcea hrevispina.

Polyarthra platypter^a.

„ serrulata.

Raitulus cimolius.

„ tecta.

Rotifer macrurus.

,, sp., with one long

Sacculvs viridis.

and one short posterior

Stephanoceros Eichhornii.

spine.

Synchceta pectinata.

Annrcea, sp., with one short

„ tremula.

posterior lateral spine.

Taphrocampa aimulosa.

Brachionus ruhens.

Triarthra longiseta.

Ccelopus hrachyurus.

ARACHNIDA. Arctisco-

„ cavia.

NID^.

Copens labiatus.

Macrobiotus Hufelandii.

Dinocharis tetractis.

INSECTA. DiPTERA.

Euchlanis triquetra.

Corethraplumicornis, larva of.

Attendance : Eleven members of the Club, three members of
other Societies, and three visitors. Total, 17.

85

May 9th.

Objects Found on the Excursion to Hadley Wood, by
Messrs. Oakden, Parsons, and Kousselet.

PROTOZOA,

Coleps hirtus.
Condylo stoma stagnate.
Dinohryon sertularia.
Stentor niger.
VERMES. Kotifera.
Anurcea aculeata.

„ hrevispina.

„ serrulata.

„ tecta.
Asplanchna Brighiwellii.
Brachionus angularis.

„ pala.
Ccelopus hrachyurus.
Hydatina senta.
Noteus quadricornis.
Notholca acuminata.
Notops brachionus.

Rhinops vitrea.
Rotifer macrurus.
,j vulgaris.
Synchceta pectinata.
„ tremula.
„ sp., having two of
the four coronal styles
situated laterially, almost
immediately over the
auricles; small.
Triarthra longiseta.
CR USTACEA. Entomos-

TRACA.

Bosmina Icevis.

J , longirostris,
AR AC UN I DA. Aoarina.
Eylais extendens.
Hygrobates, sp.

Folyarthra platyptera.

Attendance : Seventeen members of the Clubj five members of
other Societies, and four visitors. Total, 26.

May 23rd.

Objects Found on the Excursion to Oxshott, by Messrs.
Chapman, Parsons, Rousselet, and Western.

PROTOZOA.

Amphileptus anser.
Condylostoma stagnate.
Dinohryon sertularia.
Englena acus.
Stentor polymorphus.
Vorticella cJiloro stigma.
VERMES. Rotifera.
Anurcea aculeata,
nna.

curvicorms.

Anuroia serrulata.
„ tecta.

„ sp., with only one
posterior lateral spine.
AnurcBaf sp., with one long
and one short posterior
spine.
Brachionus angularis.
„ pala,

„ rubens.

urceolaris.

86

CepTialosiplion Umnias.
CcBlopus hracliyurus.
Conochilus volvox.
Copeus cerherus.

,, imcliyurus.
Diaschiza, sp.
Dinocharis tetractis.
Kosphora aurita.
Euchlanis triquetra.
Floscularia cornuta.
„ coronetta.

,, ornata.

Furcularia ensifera.
Hydatina senta.
Limnias myriophilli (Wes-
tern = Limnoides myrio-
2)hiUi, Tatem).
Mastigocerca hicornis.
AJastigocerca hicrisatta.
,, carinata.

„ elongata.

„ rattus.

Melicerta conifera.
„ ring ens.
Notholca scapha.
Notommata saccigera.
Notops brachioiius.

,, hyptopiis.
CEcistes crystallinus.

CEcistes lungicornit,

„ pilula,
Polyartlira platyptera,
Proales trigridia.
Pterodina 2)atina.
Rattulus cimolius.

„ sejimctipes.
Rotifer macroceros.

,, tardus.

„ vulgaris.
Sacculus viridis.
Salpina macrantha.

„ mucronata.
Stephanops lamellar is.

,, muticus.

Synchceta pectinata.

., tremula.

Triarthra longiseta.
Triphylus lacustris.
CR USTA CEA . Entomos-

TRACA.

Diaptomus castor.
Macrothrix laticornis.
ARACHNIDA. Arctisco-

Macrohiotus Hufelandii.
MOLLUSGOIDA. Polyzoa.
Plumatella repens, recently
hatched from statoblast.

Attendance : Six members of the Club, one member of the
Hackney M. and N. H. Society, and two visitors. Total, 9.

June 6th.

Objects Found on the Excursion to Woking, by Messrs.
Parsons and Rousselet.

PROTOZOA.

Ampliileptus gigas.
Opercularia nutans.
Peridinium tahulatum.

Stentor niger.

Stichotricha remex.
Trachelocerca olor.

87

Vaginicola crystallina.
Vorticella cMorostigma.

VERMES. KOTIFERA.

Anurcea aculeata.
,, cochlearis.
„ curvicornis.
Ccelopus brachyurus.
Conochilus volvox.
Copeus pachyurus.
Dinocharis pocillum, var.
Euchlanis p)arva (Rous-

selet), U.S.
Euchlanis triquetra.
Floscularia campanulata.

„ cornuta.

Floscularia coronetta.
Mastigocerca rattus.
Melicerta conifera.
„ ring ens.
Attendance : Eleven members
Total, 12.

Notholca labis.
Notommato cyrtopus.

,, lacinulata.

Notops hrachionus.
CEcistes hrachiatus.

„ crystallinus.

„ stygis.
Philodina macrostyla,
Proales parasita.
Rotijer macroceros.

„ macrurus.
Stephanoceros Eichhornii.
SyncTiceta pectinata.

„ small sp., same as
found at Hadley.
Taphrocampa annulosa.
AEACRNIDA. Arctisco-

Macrohiotus Hufelandii.
of the Club and one visitor.

June 20tb.

Objects Found on the Excursion to Whitstable, by Messrs.
Hembry and Waddington.
PROTOZOA. Spirorhis communis.

Noctileuca miliaris.
PORIFERA.
Grantia.
Leucosolenia.
CCELENTERATA. Hydro-

ZOA.

Campanulina acuminata.
Campanularia.
Hydractinia echinata.
Sertularia.
Syncoryne.
Tubular ia indivisa,
ECHINODERMATA.
Ophiocoma.

CRUSTACEA.

Maia squinado.

Pagurus Bernhardus,

Pycnogonum.
MOLLUSCOIDA. Polyzoa.

Amatliia lendigera.

Crisia.

Flustra.

Membranipora.

Pedicellina Belgica.

Ophiura.

Solaster papposa.
VERMES.

Nereis.

88

TuNiCATA. MOLLUSC A. Gastropoda.

Ascidia virginea. Eolis,

Cynthia. Trochus.

Peroi^hora Listeri.
Attendance : Nineteen members of the Club, five members of
other Societies, and two visitors. Total, 26.

July 4th.

Objects Found on the Excursion to Guildford, by Messrs.
Chapman and Parsons.

PROTOZOA,

Anthophi/sa vegetans.
Stentor polymorjyJius .
TracheUus ovum.
PORIFERA.

Larval (planula) stage of a
spongilla.

VERMES. ROTIFERA.

Anurcea hrevispina.

Attendance : Six members of the Club, two members of other
Societies, and two visitors. Total, 10.

July 18th.

Objects Found on the Excursion to Staines, by Messrs.
Burton, Chapman, Parsons, and Western.

Brachionus pala.
Linops longipes.
Euchlams dejlexa.
Metop)idia, sp.
(Ecistes ptygura.
Polyarthra platyptera.
Pterodina patina.
Rotifer macrurus.

PROTOZOA.

Anthophysa vegetans.
Arcella vulgaris.
Ceratiuvifusus.
Dimastigoaulax cornutum.
I)inob7'yon,ST^.^ very branched

and bushy.
Folliculina ? Boltoni.
Ophrydium sessile.
Peridinium tahulatum.
Phaciis pleuronectes.
Raphidiophrys elegans.
Spirostomum ambiguum.
Stentor polymorphus.

Vorticella chloro stigma.
VERMES. Rotifera;
Anurcea aculeata.

„ hrevispina.
Brachionus Baheri.
Copeus lahiatus.
Dinocharis ijocillum.
Dip)lois propatula.
Euchlanis dilatata.

,, hyalina.

„ triquetra.
Floscularia algicola.

„ amhigua.

„ campanulata.

89

Floscularia cornuta.

„ longicaudata.

Floscularia ornata.

„ regalis.

,, trilohata.

Furcularia forjicula.

„ longiseta.

Mastigocerca hicornis.
Metopidia emarginata.
Microcodon clavus.
Monostijla bulla.

„ rattus.

Notommata saccigera.

„ tuha(¥i\iY.).

(Ecistes crystallinus.
,, longicornis.

Attendance : Eight members
Total, 9.

(Ecistes mucicola.
Philodina aculeata.
Polyarthra platyptera.
Fompholyx sulcata.
Pterodina patina.
,, reflexa.

Rotifer macroceros.

,, tardus.

,, vulgaris.
SacculuSy sp.

Stephanoceros Eichhornii.
Stephanops lamellaris.
Taphrocampa annulosa.
INSECTA. DiPTERA.

Limnobium replicatum^ larva

of.

of the Club and one visitor.

August 29th.

Objects Found on the Excursion to Kichmond Park, by
Messrs. Burton, Parsons, Kousselet, and Western.

CRYPTOGAMIA. ALG^.
Desmidiace^.

Closterium lumda.
Diatomace^.

Cocconema lanceolafum.
Diatoma vulgare.
Gomphonema acuminatum.
PROTOZOA.
Actinophrys sol.
Anthophysa vegetans.
Dinobryon sertularia.
Loxophyllum meleagris.
Ophrydium sessile.
Paramecium aurelia.
Pyxicola affiT^X
Stylonichia myiilus.
Trachelocerca olor.
Vaginicola crystallina.

Vorticella chlorostig?na.

VERMES. EOTIFERA.

Anurcea aculeata.
,, bi^evispina.
„ cochlearis,
Bracliionus doreas.

„ rubens.

Cephalo siphon limnias.
Ccelopus brachyurus.
Conochilus dossuarius.
Dinocharis pocillum.
Eosphora aurita.
Euchlanis dilatata.

,, triqiietra.
Floscularia carnpanulaia.

,, cornuta.

Limnias ceratopliylli.
Mastigocerca bicornn .

90

Melicerta conifera.
„ ringens.
Notommata aurita.
Notops hrachionus.
(Ecistes crystallinus.

„ mucicola.

„ inygura.

„ stygis (var.).
Pedal ion mirum.
Philodina citrina.
Polyarthra platyptera.
Pterodina patina.
Rotifer vulgaris.
Salpina hrevispina.

Scaridiwn longicaudum.
Stephanoce7VS Eichhornii,
SynchcEta loectinata,
Taphrocampa annulosa.

,, SaundersicB.

Dinops longipes was found
in Richmond Park by Mr.
Chapman, on October 4th.
Oligoch^ta.

(Eolosonia quaternarium.
Nais proboscidia.
MOLLUSGOIDA. Polyzoa.
Crystatella mucedo.
Plumatella repens.

,, spinigera.
Attendance : Eight members of the Club, three members of
other Societies, and two visitors. Total, 13.

September 12th.

Objects Found on the Excursion to CniNGtoRD, by Messrs.

Parsons, Scourfield, and Western.

PROTOZOA.

Actinosphcerium Eichhornii.
Amceba proteus.
Amphileptus gig as.
Arcella vulgaris.
Centropyxis aculeata.
Clathrulina elegans.
Difflugia acuminata.

„ constricta.

,, pyriformis.
Euglypha alveolata.
Stentor niger.

„ p)olymorp)hus.
Stylonichia mytilus.
Trachelocerca versatilis.
VERMES. Rotifera.
Anurcea aculeata.

„ serrulata.

„ sp., with one lateral
posterior spine.

Anuroea tecta.
Brachionus Bakeri.

,, urceolaris.

Copeus pachyurus.
Dinocharis tetraciis.
Diplois propatula.
Euchlanis dilatata.
Furcularia longiseta.
Mastigocera hicornis.
Notops brachionus.
Polyarthra plaiyj^tera.
Rotifer macrurus.
Salpina eustala.

,, macrantha.

„ mucronata.
Scaridium longicaudum.
Triphylus lacustris.
CR VST ACE A. Entomos-

TRACA.

Alona guttata.

91

Alona intermedia.
Alonella excisa.

,, nana.
Bosmina longirostris.
Canthocamptus mimitus.
Ceriodaphnia reticulata,

„ rotunda.

Chydorus sphcericns.
Cyclops serrulatus.

„ signatus.
tenuicornis.

Cyclops Thomasi.

,, viridis.
Cypria serena.
Cypridopsis vidua.
Daphnia pxdex.

,, hyalina.

Diaptomus ? gracilis.

Pleuroxus trigonellus.

,, truncatus.

,, uncinatus.

Simocephalus vetulus.

Attendance : Ten members of the Club, three members of
other Societies, and one visitor. Total, 14.

September 26th.

Objects Found on the Excursion to Hayes and Keston
Commons, by Messrs. Parsons and Rousselet.

PROTOZOA.

Amphileptus flagellatus.

VERMES. EOTIFERA.

Anu7'(Ba cochlearis.

„ serrulata.

,, tecta.
Asplanchia p)riodonta.
Conochilus unicornis (Rous-
selet), n.s.
Dinocharis Collinsii.

Mastigocerca rattus.
Noteus quadricornis.
Pedalion mirum.
Philodina macrostyla.
Polyarthra platyptera.
Pompholyx sulcata.
Rotifer niacroceros.
Salpina mucronata.

,, spinigera.
Stephanops chlcena.
Synchceta pectinata.

Euchlanis parva.
Attendance : Eight members of the Club and four members of
other Societies. Total, 12.

October 10th.
Objects Found on the Excursion to Wood Street.

VERMES. Rotifera.

Adineta vaga.

Anurcea serrulata.

Brachionus urceolaris.

Callidina magna-calcarata,
n.s.
Attendance : Three members of the Club. Afternoon wet.

Copeiis ptachyurus.
Pterodina cceca, n.s.
Sacculus viridis.
Synchceta tremula.

92

PROCEEDINGS.

Decembee 4th, 1891. — Gonveesational Meeting.

The following objects were exhibited : —

Worms from fresh-water stream... Mr. F. W. Andrew.

Mysis oculata.,. ... ... ... Mr. E. T. Browne.

Amceha radulosa ... ... ... Mr. W. Burton.

Spathe of Iris germanica ... ... Mr. G. E. Mainland.

101 Diatoms, selected from cement- 1 -jyj- tt Morland
stein from Sendai, W. Japan J

Decembee 18th, 1891. — Oedinaet Meeting.

A. D. Michael, Esq., F.L.S., F.R.M.S., Vice-President, in

the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
Members of the Club :— Mr. Alfred W. Jones, Mr. J. B. Bessell,
Mr. G. C. Drew, Mr. Joseph Stevens, Mr. H. R. Arnold, Mr. A.
M. Cheyne, Mr. H. S. Collins, and Mr. F. H. Evans.

The following additions to the Library and Cabinet were
announced : —

"Proceedings of the Geologists'") t p i.

Association" )

" Proceedings of the Belgian Micro- ")
scopical Society "... ... )

"Proceedings of the New York")

Microscopical Society " ... )

" Proceedings of the Canadian")

Institute" 3

"The American Monthly Micro-)
scopical Journal"... ... J

" The Botanical Gazette "

" Le Diatomiste " ...

93

Old work on Zoophytes, Pallas | ^^, Scherron.
^' Elenchus zoophytu'm'^ ... )

Two sections of teeth Mr. D. Caush.

Six slides — spicules of fish ... Mr. F. M. Half ord.

The thanks of the Club were voted to the donors.

Mr. Karop exhibited a microscope designed by Mr. T. T.
Johnson, the chief point of novelty about which was the
ingeniously contrived screw adjustment for focussing the sub-
stage. He expressed a hope that a further improvement might
be effected by doing away with the heavy foot and the spring-
clips upon the stage.

The Chairman entirely agreed with Mr. Karop as to the
extremely convenient form given to the substage movement
before them ; it was not only ingenious, but also likely to be
very useful. He agreed also as to the stage clips, which had
only one advantage, namely, the ease with which they could be
taken out.

Mr. Karop said he should like to say a few words on one or
two small matters, as the agenda paper was not very full that
evening. Firstly, we may, as microscopists, be allowed without
pedantry to take cognizance of trifling things, and accuracy even
in non-essential concerns is desirable. Now English is a very
elastic language, and we often have to incorporate terms for
which we can find no equivalent ready to hand ; to this, of
course, there need be no objection. But latterly I have noticed
a word, for the introduction of which, under correction, I think
Mr. Nelson is responsible, and I see it has gained admission to
the new edition of " Carpenter," and against its furthur use I
would desire to raise a mild protest. I allude to the term hup or
loups, used chiefly in connection with Steinheil's formula for
aplanatic magnifiers, but also for other similar combinations. It
is a French word, the German equivalent being Uipe, plural
lupen, and in both it applies to any hand or pocket magnifier,
whether a single or compound lens, and therefore it should not
be restricted to one or two combinations. But it is unnecessary.
Why not speak of a Steinheil or other maker's triplet
as we do of a Wollaston's doublet, or add "magnifier" to
indicate the general use of such combination?

In reading the chapter on mounting in the new " Carpenter "
I have come across two curious things which require notice,

94

althougli I trust I shall be exonerated from any desire to make
pettifogging criticisms. The first is a note, on page 428, on the
authority of Mr. Cole, who says alcohol is useless for harden-
ing, because of the water contained i7i it. This is a very extra-
ordinary statement, and I will make no further comment.

The second is one that has often been repeated in books, and
may be very misleading. In treating of aqueous media for exami-
nation and preservation of specimens, on page 442, reference is
made to " fruit juice." Now most ordinary people, on reading
this bare statement, would think it meant the juice expressed
from some succulent fruit, say plums. It is really a free and
ignorant translation by Mr. Bolles Lee, " Microtomists' Vade-
Mecum," of the Grerman " frucht-wasser " or liquor amnii, the
fluid in which the foetus is suspended in its mother's womb ; a
material not easily obtained by the generality of microscopists.
It would be equally accurate to recommend "eye-water," mean-
ing thereby aqueous humour, which was formerly used for the
same purpose.

Mr. E. M. Nelson said he entirely agreed with Mr. Karop as
to the remarks he had made about the word " loup." He
believed he was responsible for its introduction, having taken
it from a catalogue and made use of it at a meeting in connec-
tion with a hand-lens. It was apt to be misleading, and should,
therefore, be displaced by those which more accurately described
the kind of lens or combination intended.

The Chairman said they all knew and respected Dr. Dallinger
so thoroughly, that knowing also how well everything he under-
took was sure to be done, any oversights, such as those men-
tioned, were likely to appear the greater by contrast. The
special parts of the book which had been entirely written by Dr.
Dallinger were so well done as to be almost beyond praise, and
when they looked into the remainder it would be seen that the
labour involved was almost too great for any one man, and,
therefore, it was not surprising that other parts, which he did
not write, did not come up to the same standard, that having
to concentrate his attention upon the optical parts of the
volume some other parts should have escaped the same careful
treatment. Dr. Dallinger's extreme sensitiveness and un-
willingness to trouble others had possibly prevented him from
ctfclling in the aid of those who were specialists in particular

96

branches, and no portion of the book showed the need o£ such
assistance more than the chapter on mounting, so that a young
microscopist would not be able to obtain from that chapter help
which would enable him to mount an insect in a satisfactory
way. There were few books, even of less technical character,
of which it could be said that they were absolutely perfect,
whilst with regard to this it would be freely admitted that
those portions to which Dr. Dallinger had given personal
attention were very admirably done.

Mr. H. Morland read a paper " On a Method of Mounting
Diatoms," specimens of the metal discs mentioned being ex-
hibited in illustration.

Mr. Hailes said he had used something very like this plan
for some years in mounting Foraminif era, only instead of using
metal he had found discs of paper or card to be best ; they were
easily punched out with a pair of shoemaker's pincers, and the
materials could be obtained of any thickness. Balsam ran in
quite freely, so that practically the card or paper disc was
mounted in balsam with the object.

Mr. Morland said that his object in using metal was to
know exactly the thickness between the cover and the slide. It
was not merely for the sake of protecting the diatoms.

The Chairman said no doubt all who were in the habit of
mounting objects were accustomed to use something to prevent
the cover glasses from pressing upon delicate objects. He had
himself sometimes used small glass beads for the purpose, but
this was a very different matter from that aimed at by Mr. Mor-
land, who wanted to get a substance of a certain definite thick-
ness, and this not only kept oU the pressure, but gave him an
easy means of regulating the distance between the cover and the
slip. He thought the suggestion would be of value to those
who wanted to mount very minute flat" objects for examination
under very high powers. He had, however, been under the
impression that gum or any other adhesive mixture was not
advantageous and not necessary in mounting objects of this
kind.

Mr. Morland said that some forms could be mounted very
well without.

The thanks of the meeting were unanimously voted to Mr.
Morland for his communication.

96

Announcements of meetings, etc., for the ensuing month
were then made, and the meeting resolved itself into the
usual conversazione, at which the following objects were ex-
hibited : —

Melicerta tyro Mr. F. W. Andrew.

Crystals of carbonate of lime from | ^^ ^ ^ Mainland,
a horse ... ... ... J

Triceratium Patagonicum ... .., Mr. H. Morland.

January 1st, 1892. — Conversational Meeting.

The following objects were exhibited : —

Nereis (Marine annelid) ... ... Mr. E. T. Browne.

Bero Mr. W. Burton.

Leaf of Borago zeylandica Mr. G. E. Mainland.

Tubercle Bacilli, from a Frog ... Mr. C. J. Pound.
Tinojoorus haculatus ... ... ... Mr. J. J. Vezey.

January 16th, 1892. — Ordinary Meeting.

A. D. Michael, Esq., F.L.S., F.R.M.S., etc., Vice-President, in

the Chair.

The Chairman said he regretted very much to have to
announce that their Secretary, Mr. Karop, was laid up with
the prevailing epidemic, and, therefore, unable to be in his
place that evening. They would be glad to hear that he was
progressing favourably, though he would not, perhaps, be able
to go out for two or three weeks. Mr. Hailes had kindly
undertaken the duties of Secretary meanwhile.

Mr. Hailes then read the minutes of the preceding meeting,
which were duly confirmed and signed by the Chairman.

The following gentlemen were balloted for and duly elected
Members of the Club : — Veterinary Captain Rutherford, Mr.
W. H. Maw, M. Grustave Goffi, Mr. Wm. J. Pierce, Mr. Chas.
D. Soar, Mr. David Bryce, Mr. James Mare, jun., and Mr. H. S.
Hogan.

The following additions to the Library were announced : —
" Proceedings of the Essex Natural^ ^ -r, ,
History Society" | I" Exchange.

97

"Annual Report of the Brighton and^ t -p, ,
o. T TT- ri ,, y ^''^ -bxchang-e.

Sussex Natural History Society J

" The ]VI icroscope " ... ... ... ... „

'' The Botanical Gazette " ... ... ... „

" Science Grossip " ... ... ... ... „

" The American Monthly MicroscopicaH
Journal" ... ... ... ... j

" The American Naturalist " ... ... „

" Annals of Natural History " ... ... Purchased,

"Grevillea"

The Chairman reminded the Members present that by the
death of Cardinal Manning on the previous day the Qaekett
Club had lost a member of nearly twenty years' standing.
He attended their Annual Meeting on July 26th, 1872, to hear
the Presidential Address, then delivered by Dr. Lionel S. Beale,
and was so much interested in the proceedings that he ex-
pressed a desire to become a Member. He was accordingly
nominated at the following meeting, and elected at the Ordinary
Meeting, Sept. 27th, 1872. Though not familiar to them as an
attendant at their meetings, nor distinguished amongst them
as a microscopist, there could be no doubt that by his death one
of the most distinguished names had been removed from their
list of Members.

The Chairman said it was also a matter for regret that Dr.
Dallinger's health prevented him. from being present with them
that evening ; he believed there was nothing serious the
matter, but he was under the necessity of taking care not to
expose himself to any chill. He had, however, written to
express his further regret that an engagement of old standing
would prevent him from being present also at their next
meeting to deliver the customary Annual Address, and under
these circumstances he asked their permission to postpone the
delivery of that address until the meeting in March. They
could not, of course, postpone the Annual Meeting, so that on
February 19th the ordinary business of the Annual Meeting
would be proceeded with as usual, but papers would be taken
afterwards instead of the President's Address.

In preparation for the Annual Meeting, the Chairman said
it would be necessary to appoint two gentlemen to serve as
Auditors of the accounts of the past year. The Committee
JouRN. Q. M. C, Series II., No. 31. 7

had nominated Mr. Hainworth to act on their behalf, and it
now remained for the Members present to elect another gentle-
man to represent them as Auditor.

Mr. J. Terry was then proposed as Auditor by Mr. Chapman,
seconded by Mr. Waller, and duly elected.

The Chairman said their next business was to nominate
gentlemen to fill the vacancies caused upon the Committee
by the retirement by rotation of Messrs. Morland, Dadswell,
Reeves, and Rousselet, and by the removal of Mr. Yezey to the
office of Treasurer. The four retiring Members were, of course,
eligible for re-election.

The following gentlemen were then nominated as candidates
for the five vacancies mentioned : —

Mr. G. E. Mainland, nominated by Mr. Freeman and
seconded by Mr. Hardy.

Mr. H. Morland, nominated by Mr. Allen and seconded by
Mr. Burton.

Mr. E. Dadswell, nominated by Mr. Chapman and seconded
by Mr. Brown.

Mr. W. W. Reeves, nominated by Mr. Ward and seconded
by Mr. Newton.

Mr. E. T. Newton, nominated by Mr. Reed and seconded by
Mr. Waller.

Mr. C. Rousselet, nominated by Mr. Western and seconded
by Mr. Pound.

Mr. J. G. Waller, nominated by Mr. Nelson and seconded by
Mr. Morland.

Mr. J. W. Burton, nominated by Mr. A. Smith and seconded
by Mr. Freeman.

Mr. Bryce read a paper " On some New Rotifers of the
genus Callidina," illustrating the subject by drawings on
paper, and enlarged on the blackboard, and by specimens
shown under the microscope.

The Chairman said that the Members of the Club had been
so active and fortunate amongst the Rotifers, that this paper
could not fail to interest many who, he hoped, would add some
remarks upon the subject.

Mr. Western regretted that he had nothing to add to the
description given, but he wished to say that in his opinion the
paper to which they liad just listened was a very valuable con-

99

tribution to the life history of a little studied p^enus. He had
not much studied it himself, because its habitat differed from
those of the ordinary Rotifers ; but having had some specimens
given to him he had found them very interesting.

The Chairman hoped they would have been favoured with
more remarks from Members present upon this paper, which
opened up a subject of the very highest interest, and one
which was well worthy of being worked out. The paper itself
was not only a carefully-considered descrijDtion of the group,
but it also opened up a question of symbiosis, a subject in
itself at present very imperfectly understood, but, nevertheless,
one of great importance and interest. As dealing with the
actual life history of these Rotifers, the paper was also one of
very great interest and importance.

Mr. E. T. Newton said he should be glad to hear in what way
this symbiosis was considered to be beneficial to the plant, and
also if the apertures described were natural to the moss, or were
made by the Rotifers.

Mr. Bryce thanked the members of the Club for the kind way
in which they had received his communication. As regarded
the idea of symbiosis, Dr. Zelinka had drawn attention to it, but
so far it would seem to rest very much upon supposition. The
suggestion was made that it might be of benefit to the plant on
account of the destruction of spores by the Rotifers, especially
those of Nostoc, which could, if not removed, be very injurious to
the plant. The Rotifers lodging in the cavities would eat up the
spores of the Nostoc as soon as they appeared, and so prevent the
mischief which their development would occasion. As regarded
the apertures in the sphagnum cells, it would seem that these
were entirely natural, as indeed might be seen if the specimens
exhibited under the microscope in the room were examined.

Mr. R. T. Lewis read a "Note on a Species of Ixodes found
on a South African Lizard," the subject being illustrated by
specimens shown under the microscope, as well as by coloured
drawings and diagrams.

The Chairman said that as this subject was connected with the
Acarina he should no doubt be expected to say something about
it. It was by no means an easy job to identify Ticks, because
the information concerning them was very much scattered, and
the balk was not at all easily accessible. He would, therefore.

100

be a rather bold individual who would say that any distinctively
marked specimen which he found was a new species. Ixodidae
from Lizards had been described on many occasions ; they were
mentioned by Lucas, whose great work on the " Natural History
of Algeria " was remarkably complete, although his descriptions
of Ixodidae were not equal to his other subjects. The homologies
of the rostrum and mouth-organs were more or less understood,
but not so well perhaps as they might be if the comparisons
were less often made to the mouth-organs of insects instead of
to those of the Arachnida. Mr. Lewis was perfectly right in
saying that the larger number of writers upon the subject have
called that portion which carries the barbs the labium, and in
many other groups the same kind of use is made of the term.
But, for all that, the use of this term conveyed an entirely false
idea, because the organ was not the homologue of the labium of
an insect. It was really a maxillary lip formed by the fusion
of the maxillse ; they were completely fused together at the
base, and although they thus formed a kind of lip it was
certainly a maxillary lip. Its position and homology was
defined clearly by the palpi which were annexed to it, because
these were the maxillary palpi, and certainly not labial palpi.
In the same manner it had been asserted that the first paix of
legs really represented the labial palpi, thereby accounting for
the fact that whereas insects proper had only six legs these
creatures had eight. This supposition seemed rather taking at
first, but it was negatived by the fact that in the immature
stages there were only three pairs of legs, and that it was only
at a later stage that the fourth pair appeared, and when they
did so the}'- were found to be abdominal, and not belonging to the
Cephalothorax at all. The question as to there being two pairs
of mandibles had also been raised before by Haller and others.
He asserted that there were two pair of mandibles. Fusten-
berg also held that there were two paii's, but all the analogies
of the subject were strongly against it, although there might
be one pair of mandibles and one pair of something else beside.
The sheath was more or less common in many groups of Acarina,
but it did not assume the same form as in the IxodidjB. With
regard to the remarks made as to the inconvenience produced
by the attacks of Ixodes, so far from their being in any way
exao-gernted, he conld only say that they wore far below the

101

mark, for so great was the damage done and trouble occasioned
by them in hot climates, especially in the West Indies, that
there the inhabitants were inquiring whether some Government
aid could not be given to assist them in dealing with the mis-
chief, or in ascertaining some means of doing so. Of course, as
Mr. Lewis had mentioned, a great deal of the trouble which
arose in the case of these bites was due to the rostrum getting
broken off in the wound. Animals would be likely to scratch
the Ticks off, and persons would pull them off roughly when
they felt themselves bitten, so that there would be in most
cases portions left behind. If they examined the specimens of
Ixodidfe sent home to this country they would find that in nine
cases out of ten the rostrum was broken off. The sucking
powers of these creatures were very remarkable, but he did not
think that the muscular distension of the abdomen was the
means by which the suction was produced ; the sucking organ
was probably the pharynx, and the abdomen was merely the
receptacle into which the blood was passed. The pharynx was
furnished with a remarkable set of muscles, which enabled it
to act like a powerful force pump. Measurements of Ticks
were of very little use unless you knew whether the individuals
were full fed or not, because so great were their powers of dis-
tension that a creature which when empty was no larger than a
grain of mustard seed would when gorged swell up to the size
of a person's thumb-nail. Prof. Leidy was so struck with this
remarkable distension that he took the trouble to weigh some
of the individuals before and after they had been feeding, and
he found that in some instances they weighed nearly 100 times
as much when full fed as they did before they began. He
might mention also that latterly the Ixodidse had been divided
up into many genera, so that now the word Ixodes was used in
a very restricted sense, as compared with its application many
years ago.

Mr. Western said he could quite corroborate what had been
said as to the enormous increase in the size of these creatures
after sucking blood, and also as to the amount of mischief they
did by their attacks. In the East Indies their enormous
numbers made them a source of great annoyance, and from the
considerable amount of irritation set up they caused various
diseases amongst animals, not only by the bites themselves,

102

but by their worrying effects. He had kept dogs, and had
found them sometimes with their ears stuffed completely full
of these Ticks.

Announcements for the ensuing month were then made, and
the meeting terminated with the usual conversazione, the
following objects being exhibited : —

Callidina reclusa, in sphagnum cell ... Mr. D. Bryce.

Callidina lata ... "... ... ... ,, „

Photo of Moon

Ixodes from African Lizard, and
mouth-organs of same

Tricei'atium divisum

Cocci of Pneumonia ...

Mr.

J. D. Hardy.

Mr.

R. T. Lewis.

Mr.

H. Morland.

Mr.

C. J. Pound.

February 5th, 1892. — Conversational Meeting.

The following objects were exhibited : —
Fredericella sultana ...
Teeth of Dogfish, Scyllium canicula.
Triceratmm constans ...

Mr.

F. W. Andrew.

Mr.

E. T. Browne.

Mr.

H. Morland.

February 19th, 1892. — Twenty-Sixth Annual Meeting.

A. D. Michael, Esq., F.L.S., F.R.M.S., etc., Vice-President, in

the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
Members of the Club : — Mr. Thos. A. G.Powell, Mr. Washington
R. Brook, Mr. John Albanj^, Mr. W. E. Samson, Mr. W. H. Brown,
Mr. Lewis Wright, Mr. W. G. Rumbold, Mr. Henry M. Bernard,
Mr. Henry Burgess, and Mr. Herbert Snelling.

The following additions to the Library were announced, and
thanks voted to the donors : —

*' The Botanical Gazette " ... In Exchange.

" The Monthly Microscopical Journal " ... ,,

" Proceedings of the Royal Society" ... „

" Report of the Leeuwenhoek Club" ... „

" The Microscope ".. . ... ... ... „

103

'' Journal of the New York Microscopical') j Exchange

Society" ) ^ '

" Journal of the Royal Microscopical")

Society" )

" Proceedings of the Scientific Society of)

Manitoba" i

" Transactions of the Natural History )

Society of Kieff " )

" Annals of Natural History " ... ... Purchased.

" Quarterly Journal of Microscopical")
cience ... ... ... ^

The Secretary having remarked that this annual meeting
was the 300th meeting of the Club,

The Chairman appointed Mr. Chapman and Mr. J. M. Allen
to act as Scrutineers, and the ballot for Officers and Committee
for the ensuing year was proceeded with.

Mr. Karop called attention to the fact that the name of Mr.
W. W. Reeves had been erased from the list of Members nomi-
nated to fill the vacancies on the Committee at the last
meeting. The Members would, he felt sure, deeply regret to
hear that, since that meeting, Mr. Reeves had become so
seriously ill that there appeared to be no hope of his being able
to discharge the duties if elected, so that his name had conse-
quently been withdrawn.

The Chairman then called upon the Secretary to read the
26th Annnal Report of the Club.

The Treasurer's Annual Statement of Accounts and duly-
audited Balance Sheet were read by Mr. Vezey.

Mr. J. M. Allen moved, and Mr. B. W. Priest seconded the
proposal, " That the Reports now read be received and adopted,
and that they be printed and circulated in the usual way." —
Carried unanimously.

The Chairman said it would no doubt be noticed from the
Report that the very successful exhibition meeting held last
year was paid for, not out of the funds of the Society, but
by private subscriptions of certain of the Members. It was
felt by many that it would be a very pleasant thing if they
could have another meeting of the same character, but as one
result of their moving to Hanover Square, added to the cost of
the Journal, was to leave them very little to spend in the

104

direction of entertainmcrits, it wns proposed to defray the cost
of tliis special meeting in a similar way to the last. As there
were doubtless many Members who would be glad to contri-
bute something towards this object, it was suggested that they
should put themselves in communication with Mr. Parsons,
who would be very pleased to receive subscriptions for the
purpose. There was no limit set as to the smallness of the sums
to be given, and whether anything was given or not was of
course a purely optional matter.

The Scrutineers at this point having handed in ther Report
as to the result of the ballot, it was announced by the Chair-
man that the whole of the Officers named on the list had been
elected ; and that the five following Members had been elected
to till the vacancies on the Committee: — Messrs. Mainland,
Morland, Dadswell, Waller, and Rousselet.

It was then moved by Mr. C. West, seconded by Mr. Goodwin,
and unanimously resolved, " That the best thanks of the Club
be given to the Auditors and Scmitineers for their services."

Mr. J. G-. Waller said he had the very pleasant duty to per-
form of proposing " That their hearty thanks be given to the
Officers and Committee of the Club for their services during the
past year." He might, if it were necessary, say a great deal in
support of this motion, but he felt sure that all knew how well
deserved these thanks were, and they would doubtless agree
with him that there w^as not a better served Society in this
respect than the " Quekett."

The motion, having been seconded by Mr. Chapman, was put
to the meeting and carried by acclamation.

Mr. Karop, in acknowledging the vote of thanks, assured the
Members that so far as he was concerned, and he was quite sure
that it was the case of his brother officers also, the duties under-
taken on behalf of the Club were nothing but a pleasure.

Mr. Vezey also thanked the members for the honour done to
him by his election as their Treasurer, and expressed a hojDC
that he might be able as faithfully to perform the duties as his
predecessor, Mr. Gay, had done.

The Chairman said they would remember that it was
announced at their last meeting that owing to an engagement
of long standing Dr. Dallinger would be unable to be present at
the Annuil Meeting, and that his annual address would in con-
sequence be postponed to the Ordinary Meeting in March.

105

Mr. Buffhamrcad a paper " On a New Marine Chantransia,"
illustrated by drawings upon the blackboard; also a paper
" On the Conjugation of a Marine Diatom," Orthoneis hinotata,
Grunow, illustrated by diagrams and drawings.

Mr. Morland felt sure the members would feel greatly obliged
to Mr. Bulfham for his very interesting communication. He
could himself add nothing to what had been said, these " horns "
being entirely new to him as matters of observation, nor did
he know that they had been seen before in the conjugation of
diatoms.

Mr. Karop also expressed the indebtedness of the Club to Mr.
Buffham for his communication. He seemed to be at present
the only member who took up the study of diatoms with the
idea of investigating their life history and processes of reproduc-
tion. If only some of the time and skill spent in the examina-
tion of the markings could be devoted to the line pursued by
Mr. Buff ham very valuable results might be expected. As to
these horns, he could not think that they were simply for
purposes of protection, because other diatoms had not got them,
and he also thought that if these gelatinous filaments were
protective they would be more frequently found. The observa-
tions appeared to be extremely valuable, and they were greatly
indebted to Mr. Buft'ham for the description he had given.

The Chairman said their thanks were due to Mr. Buff ham for
his most interesting paper. It was always a pleasure to hear
him speak upon the subject of the sexual processes of the
Florida?, on which he was an authority. He had much pleasure,
therefore, in moving a cordial vote of thanks for his communi-
cation. — Carried nem. dis.

Mr. Buff ham said he was much obliged to the members for
the cordial way in which his paper had been received. If he
had conveyed the impression that the horns were something
simply belonging to this conjugating form, he should like to
correct it, because the vegetative diatom also showed the
peculiarity. This observation was not new, as Grunow men-
tioned having found them. With regard to their apparently
breaking up into smaller forms, he thought there might possibly
be sometimes a little colony attached to the valve, and in cases
of conjugation he always thought it advisable to see if there
were any vegetative as well as sporangial frustules. In as
many as 42 cases out of 46 he had found these horns present.

106

The Secretary said they had received a communication from
Mr. Nelson " On a Simple Method of Finding the Refractive
Index of Mounting Media," but owing to the lateness of the
hour it was decided that this should be taken as read.

Announcements for the ensuing month were then made.
The attention of Members was called to the fact that as the
third Friday in April would be Good Friday the Ordinary Meet-
ing for that month would have to be omitted, and the meeting
terminated with the usual conversazione, the following objects
being exhibited by Mr. Buffliam : —

Ghantransia trifolia, n.s., with monospores, and Orthoneis
hinotata, on Calothrix confervicola.

March 4th, 1892. — Conversational Meeting.

The following objects were exhibited : —

^ohosoma quaternarium ... ... Mr. F. W. Andrew.

Head of Nereis
Foraminifera from Jersey
Eunotogramma joroductum
Sponge, Sannginella jpwpa .
Macrotrachela papillosa

Mr. E. T. Browne.
Mr. G. E. Mainland.
Mr. H. Morland.
Mr. B. W. Priest.
Mr. P. Thompson.

March 18th, 1892.— Ordinary Meeting.

Dr. W. H. Dallinger, F.R.S., F.R.M.S., etc., President, in the

Chair.
The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
Members of the Club :— Mr. John H. Tallent, Mr. T. F. Black,
Mr. W. H. Brown, Rev. E. P. Marriott, Mr. C. G. Seligmann,
Mr. John Elliott, Mr. Frederick M. Halford, and Mr. J. A.
Daniell.

The following donations were announced : —

" Science Gossip " In Exchange.

" The American Monthly Microscopical )
Journal" ... ... ... ... J

" The Botanical Gazette " ... ... ... „

" Le Diatomiste " ... ... ... ... „

" Proceedings of the Royal Society " ... „

107

" Paper on a New Marine Alga " The Author.

" Annals of IS'atiiral History " ... ... Purchased.

Mr. Morland exhibited one of Brown and Sharpe's American
wire gauges, which he thought would be found very useful as
affording an easy means of ascertaining the thickness of cover
glasses. Measurements could quickly and easily be made
down to the j-g-^Q-th of an inch. The gauge was handed round
for inspection.

Mr. R. T. Lewis said as this subject had been brought for-
ward he might again mention Trotter's patent gauge as being
also available for the same purpose. This was made of steel,
and being only two inches long was easily carried in the waist-
coat pocket. Its construction was very ingenious, and by
means of two sliding scales on the Yernier principle it showed
six measurements at the same time, i.e., the English standard
wire gauge with its equivalents in decimals of an inch and of a
millimetre were shown on one face, and on the other, for the use
of electricians and others, the sectional area of the round wire
in fractional parts of a square inch, the weight of copper wire
per 100 feet, and the quantity of current it would theoretically
carry. It required something of an education to be able to use
it with facility, but, like most other things, when you knew
how to use it the process was simple.

Mr. J. E. Ingpen said the only difficulty he saw as to the use
of these gauges was that there was likely to be a difference in
the results according to the amount of pressure applied. This
he could not help thinking was a point rather against all
micrometer gauges which worked by touch, because in the
measurement of cover glasses it was specially necessary to be
very exact.

The President said they would all recognize the desirability
of being able to ascertain the thickness of cover glasses, and
would therefore welcome any plan which would facilitate it.
They were much indebted to Mr. Morland for bringing this
little instrument before them.

The President then read his Annual Address, postponed from
the last meeting for the reason then named.

Mr. A. D. Michael thought that after the way in which it
had been received it was scarcely necessary for him to ask for
an expression of their thanks for the highly instructive address
to which they had just listened, not the least valuable part of

108

which was its eminently suggestive character. With regard to
the fear that in the future there might be danger that amateur
work might be thrown aside by the increased demands of pro-
fessional work, he thought no men were more alive to such a
danger than were the specialists themselves. But he thought
he might say, that although the high conditions required by
special work made this at the present time a special danger,
yet it could not be denied that, in this country at least, some of
the best biological work had been done by amateurs, and it
would be a bad day for science in this country when the
amateur biologist ceased to take the same interest in this kind
of work as he had done in the past, and thus ceased to
supply material facts for others to utilize. They did not need
any better illustration of the value of the work of the amateur
biologist than was furnished by the work accomplished by their
President himself, and he felt sure that the remarks which had
fallen from him that evening were such as all would do well
to consider deeply. If anyone would take up the influenza
question, for instance, and could carry out investigations with
some hope of success, it would be a matter of great importance
to science, as well as to those who were sufferers from it.
Unfortunately the popular idea at the present time might be
summed up by the statement that they did not see in what way
matters had been helped by scientific men telling them that
they had a microscopic worm in their organisms which caused
all the mischief, if they could not at the same time tell them
how it got in, or how to get it out again. He had great pleasure
in moving that the best thanks of the Club be given to the
President for his admirable address.

Mr. G. E. Mainland had great pleasure in seconding the
motion.

Mr. Michael having put the motion to the meeting, declared
it to be carried by acclamation.

The President said he felt much indebted to the Members of
the Club for the cordial and kind expression of feeling as shown
by the manner in which this resolution had been passed. It had
given him great pleasure to be associated wiih the Club, and
though his derelictions had been more frequent than he could
have wished, they had been so generously condoned that he felt
it both an honour and a pleasure to have again given him the
opportunity of occupying the chair for another year.

109

Announcements of meetings for the ensuing month were then
made, special attention being called to the exhibition meeting
arranged for May 5th, at Freemasons' Tavern, and the proceed-
ings terminated with the usual conversazione, the following
objects being exhibited : —

Chcetophora elegans ... ... ... Mr. F. W. Andrew.

Triceratium Qrayii ... ... ... Mr. H. Morland.

April 1st, 1892. — Conversationil Meeting.

The following objects were exhibited : —
Crist atella mucedo ...
Asterina gihhosa
Asilius sulcatus
Sections of Head of Minnow
Aulacodiscus excavatiis (type slide~^
of 121 specimens)

i

Mr. F. W. Andrew.
Mr. E. T. Browne.
Mr. W. Burton.
Mr. H. E. Freeman.

Mr. H. Morland.

Mat 5th, 1892. — Special Exhibition Meeting.

A special meeting was held on the above date for the exhibi-
tion of instruments and microscopical objects. The meeting
was, as last year, held at Freemasons' Tavern, on account of the
better accommodation afforded, and was attended by a large
number of Members and their friends, about 800 being present.
The following objects were exhibited : —

.. Skin from Rat's Tail.

( Young Cristatella mucedo, Seeds of

\ Pawlonia, and Plant Hairs.

Arachnoidiscus on Coralline,
f Diatoms with Zeiss's and Reichart's
Apochromatic Object Glasses, Des-
mids with Zeiss's Apochromatic
O.G., and Leaf with Hairs.
Pollen of Mallow.
Asteromjplialus stellaris.
Lophopus cristallmus, Bhinops vitrea,
Tongue of Blowfly, Polycistina,
Shells from Chalk, and Influenza
Bacillus.
Young Oysters, Antenna of Moth,
and Gizzard of Cricket.

Mr. W. Addis ...
Mr. F. W. Andrew
Mr. A. T. Ashe ...

Mr. C. Baker ...

Mr. F. W. Baxter
Mr. W. E. Baxter

Messrs. R. and J. Beck
Mr. W. A. Bevington

<

110

Mr. W. B. Bradford
Mr. A. J. Brown
Mr. E. T. Browne
Mr. D. Brjce
Mr. W. Burton . . .
Mr. A. L. Corbett

Mr. E. Dadswell

Mr. A. Dean

Mr. J. Dick

Mr. C. Dunning...

Mr. A. Earland ...

Mr. T. D. Esser...
Mr. W. W. Fletcher

Mr. H. E. Freeman
Mr. G. N. Fryer

Mr. W. Goodwin

Mr. H. F. Hailes
Rev. J. Halsey ...

Mr. J. D. Hardy

Mr. G. Hind ...
Mr. F. W. Hembry

I

Spirogyra in conjugation.

Eggs and Larva of Motb.

Sting of Wasp.

(Ecistes cristallinus.

Gristatella tnucedo, and Rotifers.

Sulphate of Quinine.

Stephanoceros Eichhornii, and Des-
mids.

Palate of Limpet, and Leaf of
Thyme.

Proboscis of Blowfly.

Sponge, Myerina claviformis, and
Zoophyte, Flumularia setacece.

Selected Foraminifera, from Philip-
pine Islands, young Starfish, and
Batterflies' Eggs.

Head of Humble Bee.

Wing of Butterfly and Leg of Dia-
mond Beetle.

Exuvia of Plant Insect, and casts of
Foraminifera from Colon.

Blood circulation in Tadpole, Head
of Hunting Spider, and Tongue of
Bee.

Pennaria calicandina, campanularia^
and Siphonia.

Foraminifera (selected) from King
George's Sound.

Young Polynce.

Hairs of Verbascum thapsus. Lingual
Ribbons of Cyclostoma elegans, and
Helix aspera, Trachea of Larva
of Dytiscits, Spicules of Sponge,
Asterina gibbosa and Volvox stel-
latus.

Head of Larva of Corethra plumi-
cornis and Stephanoceros Eich-
Jiornii.

Hydra viridis, and Larva of Gheiro-
nimus.

Ill

Mr. J. E. Ingpen
Mr. E. K. Jaques
Mr. A. J. Jenkins

Mr. W. Johnson

Mr. J. W. Lasham
Mr. R. T. Lewis
Mr. C. J. MacMn
Mr. G. E. Mainland

Mr. H. Morland...

Mr. E. T. Newton

Mr. F. A. Parsons
Messrs. Powell and

Lealand
Mr. J. W. Reed

Mr. F. Reeve ...

Mr. C. Rousselet
Mr. James Russell
Mr. "W. E. Samson
Mr. D. J. Scourfield
Mr. W. A. Skipper
Mr. J. Slade

Mr. W. Smart ...

Mr. C. D. Soar

Mr. A. T. Spriggs

Mr. J. H. Steward

Mr. A. W. Stokes

Section of Broom Twig, Stellate

Hairs Agate, and Crystals of

Flatino- cyanide of Yttrium.
Ecliinus Spines (sections).
Cyclosis in Vallisneria spiralis^

Melicerta ringens, Stentors, Ciliary

Action in Gill of Mussel, etc.
Grouped Diatoms, Spicules of

Synapta, Bacillus anthrasis, Filaria

sanguinis hominis, etc.
Grouped Sponge Spicules.
Larva of South African Cattle Tick,

Amhlyomma Hehrceum.
Hydatina senta.
Lamium 'purpureum, and Aspidiotus

conchiformis from an Apple.
Seconds hand of Watch seen through

a Beetle's Eye.
Section of Eye of Lobster, and

section of Coal.
Penneria cavalina.

Cyclosis in Vallisneria.

Section of Stem of Fagus cuprea.
New Zealand Moss, Taxodura, and

spores of Haresfoot Fern.
Rotifers.

Diatoms and Stentor.
Polycistina and Oak Buttons.
Argulus foliaceous.
Cii'culation in Tail of Tadpole.
Section of Fruit of Mallow.
Section of Human Lung, injected,

and Feather of Goldfinch.
Diatoms from St. Peter's, Hungary.
Asplenium adiantum nigrum.
Parasite . of Flying Fox, Sting of

Wasp, section of Blue Gum Tree,

Geranium Aphis, etc.
Batrachospermurn moniliforme.

112

Messrs. J. Swift and
Son

Mr. J. J. Yezey ...

Messrs. W. Watson and
Sons ...

Mr. J. C.Webb...
Mr. C. West ...

Mr. H. E. White

Section of Granite, Spines of Star-
fish, Tongue, of Fly, Sting of
Hornet, Grouped Polycistina, etc.
Frond of Fern, Davallia canariense.
Trinidad Spider, Influenza Bacillus,
Diatomaceae, Eggs of Butterflies,
Section of Drone Fly's Eye, Fertile
Seed of Sugar Cane, etc.
Polycistina.
Larva of Goretlira plumicornisy and

Head of Sand Wasp.
Fredericella Sultana.
By the kind efforts of Mr. J. W. Reed, the assistance of a
very efficient amateur band was obtained, and a choice selection
of music was performed during the evening by the following
ladies and gentlemen : —

Mr. C. Bailey ... ... ... ... ... Conductor.

Mr. Fenigstein, Miss Druitt, Miss Louisa]

Grant, Mr. E. Booth, Dr. Leonard Guthrie, L Violins.

Mr. Mcholson, Mr. J. Swale J

Mr. Walter Goss, Mr. Quarrell ... ... Violas.

Miss E. Houghton, Dr. Leonard Grant ... Violoncellos.
Miss Houghton, Dr. Dundas Grant ... Double basses.

Mr. George Goss ... ... ... ... Flute.

Mr. Cressall, Mr. Price ... ... ... Clarionettes.

Mr. Garrett ... ... Bassoon.

Mr. Blandford ... ... ... ... Horn.

Mr. Woodhouse ... ... ... ... Cornet.

Mr. P. Booth Trombone.

Mr. Marmaduke Reed ... ... ... Euphonium.

Mr. Dyer ... ... ... ... ... Tympani.

Mrs. Dundas Grant ... ... ... ... Pianoforte.

May 6th, 1892.— Conversational Meeting.

The following objects were exhibited : —

Plant hairs, Anagallus tenella ... Mr. F. W. Andrew.
Cristatella mucedo ... ... ... Mr. W. Burton.

ScoUopleura tumida... ... ... Mr. H. Morland.

Copeus lahiatus ... ... ... Mr. C. Rousselet.

118

May 20th, 1892. — Ordixary Meeting.

Dr. W. H. Dallixger, P.R.S., F.R.M.S., etc., President, in the

Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
Members of the Club : — Mr. Charles Young, Mr. A. J. Sargeant,
and Mr. John Robinson.

The following donations were announced, and the thanks of
the Club were voted to the donors : —

"Reports of the Smithsonian Institution" In' Exchange.
"Transactions of the Zoological Society)
of France" ... ... ... 3

"Joui^nal of the Royal Microscopical)

Society" 3

" Proceedings of the Royal Society" ... „

" International Journal of Microscopy "... „

" The Botanical Gazette " ... ... ... „

" The Microscope " ... ... ... ... ,,

"Proceedings of the New York MicroO
scopical Society " ... .. ^

" The American Monthly Microscopical )
Journal " ... ... ... )

" The Essex Naturalist "

" Report of the Essex Field Club "

" Proceedings of the Literary and Philo- )

sophical Society of Manchester " f

" Proceedings of the Natural History )

Society of Manitoba"... ... )

" Proceedings of the Royal Cornwall }
Society" ... ... .... )

"Report of the U.S.A. National Museum" „

" Report and Proceedings of the Ealing )
Microscopical Society " ... )

" Methods and Formulae for Staining')

Microscopical Preparations and r The Author.
Bacteria," etc., by J. W. Squire ^

One Slide— Larvae of Cattle Tick Mr. R.T.Lewis.

Mr. Karop said he had received from Colonel O'Hara a box
JouRN. Q. M. C. Series II., No. 31. 8

114

containing seven slides, which he thought were of some excep-
tional interest and had asked that they might be examined and
reported upon. Three of these were sections of the flesh of a
fowl, which was said to have turned black, and to exhibit
traces of disease, as if from the attacks of some nematode
worm. The only thing he could make out of this was that
the flesh was in a patrid condition, the .pressure used in
mounting had separated the muscular fibres, and these spaces
seemed to have been mistaken for the tracks of worms. Two
slides of liver of a bat were also supposed by Colonel O'Hara
to exhibit some diseased condition, but, to his mind, they
appeared to be perfectly healthy, and to present no uncommon
appearance. One of pine wood was not specially remarkable,
neither was that of " Hairy Tumour from Horse." Colonel
O'Hara said, in his letter, that he wished to have those of the
fowl retui-ned, the others he placed at the disposal of the Club.

They had also received a letter from Mr. Ash, accompanied
by a sample of soil from Guatemala, which was said to be very
rich in diatoms. An examination of this showed it to be of a
nature precisely resembling what was known as " Diatomite "
from the dried beds of the old Scotch Lochs. It contained
abundance of well-known freshwater forms. The quantity sent
by Mr. Ash was for distribution amongst the Members, and if
more was required it could be had in any quantity.

Mr. Scourfield read a paper oii " Some New British
Cladocera," illustrating the subject by drawings upon the
blackboard.

The President said they were greatly obliged to Mr. Scour-
field for this very interesting and useful communication. It
was certainly a curious feature in the history of the Club that
the Entomostraca seemed to have been entirely passed over,
perhaps — as was the case in other directions — because they
were so plentiful, they had been regarded as of little value as
objects of stud3^ And yet it would seem that though there had
been men who had brought the energies of a lifetime to bear
upon these organisms, there were details which had been over-
looked, and which therefore offered a promising field to those
who were disposed to investigate it. This was a matter of im-
portance at a time when it seemed certain that species as at
present constituted nuist largely go.

115^

Mr. Karop said it was certainly very curious to find tliat they
had never before had a paper on Entomostraca. When this was
mentioned to him he hardly credited the statement, but having
looked through the volumes of their " Proceedings," he was
obliged to come to the conclusion that such was the case.

Mr. E. M. Nelson gave at some length a resume of his paper
on " The Optical Principles of Binoculars," dealing especially
with the apparent conflict of the opinions of Dr. Carpenter and.
Prof. Abbe upon the subject.

The President said they were greatly indebted to Mr. Nelson
for this paper. He should not like, however, to express any
extended opinion upon it, because they had not heard it read in
its complete form, but he was quite sure that when they had it
before them they would find it well worth}' of careful reading.
The subject itself deserved more attention, because, from the
Abbe point of view, there was nothing left so unsatisfactorily
as this attempt to explain the optical theory of the binocular
microscope ; he should, therefore, have great pleasure in reading
the paper, and hoped it might be the means of giving a new
value to this form of instrument, for if only the prisms could
be made perfect, there was no reason why it should not be
possible to use it with much higher powers than hitherto.

Mr. Karop said he could not quite understand the meaning
of the terms " inside and outside the pupil," and asked if Mr.
Nelson would explain them.

Mr. Nelson said the words were not his ; he merely quoted
them from the paper, where it said that if you used one half of
the pupil you got one effect, but if you used the other half you
got the opposite effect.

The President said the idea conveyed was the assumption
that the pupil was divisible into two halves ; and the effect
produced depended upon whether they took the rays which
came through the outer halves of the pupils or those which
came through the inner halves— whichever they took was said
to determine the result.

Mr. Karop said he could not in that sense understand how
anything but confusion could result, because the perfection of
the visual image must depend upon the image falling on corre-
sponding parts of the retinae of the two eyes — that was, of
course, upon the outer side of one eye and the inner side of the

116

other eye— and they could not get the image thrown npon the
outer halves or the inner halves without getting confusion.

Mr. Crouch said the mention of the subject called to his
mind the fact that, some years ago, Mr. Ahrens made a prism
for the binocular which could be shifted so as to give in one
position a perfectly stereoscopic effect, and in the other a
pseudoscopic effect. He explained the construction of the
prism by a diagram on the board. The result was so perfect
that he rather wondered it had not been more generally
adopted.

Mr. Karop thought the principle was patented, and, there-
fore, opticians were unable to make microscopes on that
principle without paying royalties.

Mr. Crouch said he believed there was a patent, but that did
not interfere with his making several microscopes on the
principle. He got the prisms from Mr. Ahrens, who raised no
questions as to his adoption of them.

Mr. Karop said he was sure the Members of the Club would
regret to hear of the death of Mr. W. W. Reeves, which
occurred on the morning of the 18th inst. Mr. Reeves was one
of the original founders of the Club, and continued one of its
Members to the end of his life, always taking the greatest in-
terest in its affairs. Those Members who were in the habit of
attending the Excursions of the Club would remember that his
botanical knowledge was always at their service in the identi-
fication of plants found, and in this and other ways he would
be greatly missed.

Announcements of Excursions, etc., for the ensuing month
were then made, and the meeting terminated with the usual
Conversazione, the following objects being exhibited : —

Peunatula phosphorea Mr. F. W. Andrew.

EucJilanis triqiieta ... ... ... Mr. W. Burton.

Asplanchia priodonta (mounted) ... Mr. C. Rousselet.

Mr. E. M. Nelson also exhibited a model of a binocular
microscope as invented by Cherubin d'Orleans, in 1677, and
giving perfect pseudoscopic effect.

117

TWENTY-SIXTH ANNUAL REPORT.

Your Committee has once more the satisfaction of presenting
a favourable Report.

For some years past the number of new Members has been
insufficient to make up the usual losses by resignation or death,
and attention was drawn to this fact in the Annual Reports.
It is with considerable pleasui-e, therefore, that your Committee
is able to record the election of 47 Members in the twelve
months ujd to and including December, 1891, a larger total than
in any year since 1880, and they trust every effort will be made
to maintain this increase in the future. The resignatipns and
deaths number respectively 18 and seven, leaving our present
strength at 380.

The attendances at the meetings have been unusually good,
and the papei^ and communications submitted at them quite
up to the average in number and quality, as the subjoined list
shows : —

January. — " On Spirocha^ta from Brentwater and a Tetra-
coccus from Woking," by Mr. C. J. Pound.

March. — " On Diatom Structure," by Mr. E. M. Nelson.

April. — " On some new Rotifers," by Mr. G. Western. " On
some New Organisms found in the Botanical Oardens,"
by Mr. Orenfell.

May. — " On Mounting Media of High Refractive Index," by
Mr. Ingpen.

June. — " On a New Species of Notops," by Mr. Rousselet.

September. — " On the measurement of the Refractive Indices
of Various Media used in Mounting," by Mr. Ingpen.

October. — "On a New Cysticercus and its Corresponding-
Tapeworm," by Mr. Rosseter. " On Two New Rotifers
and on the Sense of Vision in Rotifers," by Mr. Rousselet.
" On the Males of Two Rotifers hitherto Unnoticed," by
Mr. Western.

118

November. — " On Two New Rotifers," by Mr. Parsons. " On
the Diffraction Theory and Frauenhofer's Theorem," by
Mr. Nelson.

December. — " On Mounting Selected Diatoms on the Slip,"
by Mr. Mori and.

Other informal communications on new instruments and
methods of research will be found in the Proceedings.

As indicated in the last Report the finances have been most
carefully controlled, and none but necessary expenses incurred.
(For Balance Sheet see p. 121.)

The desirability of holding a Special Exhibition Meeting
being freely expressed by many, the matter received the earnest
consideration of 3^our Committee, but neither the arrangement
and capacity of the rooms available here nor the state of the
funds appeared to permit of such a meeting as has always been
associated with the name of the Quekett Club. Under these
circumstances, and with the full sanction of your Committee,
the affair was arranged by private subscription, and through
the kind offices of one of our Members the use of the large
hall at Freemasons' Tavern obtained on favourable terms. The
meeting was held in April and proved thoroughly successful,
so much so indeed that every effort will be made to repeat it
during the coming season.

The Excursions have been well attended and the results more
than usually prolific. This is particularly the case as regards
the Rotiferse, of which so many entirely new species or hitherto
undescribed males were recorded last year that, as the Presi-
dent remaiked, it would seem to be the province of the Club
to fill the (microscopic) world with these organisms. The
investigation of this group, whose position and real affinities
are by no means certainly ascertained, is eminently suited to
a working society like ours, and the discoveries made are
sufficient proof of the interest taken in the subject, and show
the value of associated research.

It is with very considerable regret that your Committee has
to announce the resignation of our esteemed Treasurer, Mr. F.
W. Gay, the more especially as it is mainly due to failing
health. He has held this responsible post for over 15 years,
and although his duties were very unostentatiously they were
always most conscientiously fulfilled, and the Committee and

119

Members generally are greatly indebted to him for his long-
continued and valuable services.

The}' are, on the other hand, extremely glad to state that the
treasurership has been accepted by Mr. J. J, Vezey, whose
position and well-known interest in the Club is sufficient
guarantee that its financial concerns will continue to be carried
on in the most efficient manner.

The Library is now, thanks to Mr. Alpheus Smith, in
thorough working order, and has been increased during the
past year by the following volumes, acquired by donation,
exchange, or purchase : —

In Exchange.

"The Microscope and its Revelations,"") Presented by

7th Edition •■ 3 the President.

" Journal of the Royal Microscopical i

Society" j

"Proceedings of the Royal Society"

" Hardwicke's Science Grossip "

" American Naturalist "

" American Monthly Microscopical )

Journal" ... ... ... ... )

" Botanical Gazette "

" The Microscope "

" La Nuova Notarisia "

" International Journal of Microscopy " ...

" Proceedings of the Geologists' Associa

tion "
"Quarterly Journal of Microscopical)

Science" ... ... ... ... j

"Annals and Magazine of Natural")

History" j

"Grevillea"

" The Anatomy, Physiology, Morphology, 1

and Development of the Blow-Fly " y „

(Prof. Lowne), Parts 1 and 2 ... )

Transactions and Proceedings of Sundry Societies.

The Cabinet has lost none of its usefulness, especially to new
Members, and the usual number of slides has been issued for
study. In any collection of the kind, however, and more
particularly one like ours, which is continually passed from

Purchased.

120

hand to hand, an occasional revision and vveeding-out of poor or
perished specimens is desirable and, indeed, necessary. This
involves very considerable labour and judgment, which it is
felt must not be thrown entirely on the Curator. Your
Committee propose, therefore, to nominate a small Sub-
Committee, who will go over the whole Cabinet and take the
responsibility of rejecting sach preparations as they may find
unfit, and, at the same time, prepare a new catalogue.

The following is a list of slides added during the year : —

Mr. R. T. Lewis

3 slides

Mr. Pound ...

... 22 „

Mr. Morland...

... 1 „

Mr. Douglas C. Caush

... 2 „

Mr. F. M. Halford ...

... 6 „

34

Your Committee has again to thank the various officers for
their several services in maintaining the routine business of
the Club. The long time which the majority of them have
held office speaks for itself as to the interest taken by them in
all appertaining to its success as a society.

Finally, your Committee has every reason to believe that the
manifest increase of vitality lately shown in microscopical
matters will continue, and, as far as concerns the social aspect,
it is of the opinion that Johnson's genial definition of a club —
' an assembly of good fellows, meeting under certain conditions '*
— pre-eminently holds in the case of the Quekett.

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122

Note on Fluorite in Apochromatic Objectives.
By E. M. ISTelson, F.R.M.S.

As fluorite is becoming scarce, an important question arises
as to whether fluorite is or is not present in any given lens.
This can readily be determined by means of a polariscope.

The ISTicols are crossed, a two-inch objective is placed on
the nose-piece, and a low eye-piece employed. The various
portions of the objective to be tested are unscrewed, and each
combination is separately placed on a glass slip on the stage
and examined in the dark polarized field. If the combination
contains fluorite, there will be a luminous white silky appear-
ance, but if there is no fluorite, then the field will remain dark.

The following are examples : — The Zeiss, 24 m.m. apochro-
matic, has three elements, of which the middle contains fluorite.
The apochromatic 12 m.m. has four elements, of which the
second and back contain fluorite. The apochromatic 6 m.m.
has three elements, of which the middle and back contain
fluorite. The apochromatic 3 m.m. has five elenients, and the
last but one contains fluorite. ^

But with i-egard to this last example it should be noted that
all 3 and 2 m.m. objectives are not alike.

123

The Rev. Father Thompson's High Refractive Medium.

Mr. E. M. ISTelson writes that it will be in the recollection of
some of the Members that a few years back he exhibited a
beautiful slide of diatoms, mounted in a very dense medium by
the Rev. Father Thompson. He is now, through the kindness
of Father Thompson, able to communicate the recipe of the
composition to the Club. He still has the same slide in his
possession, and,. so far as it is possible to judge, it has remained
unaltered. He therefore begs to commend Father Thompson's
high refractive medium to the especial notice of the Club as
the best thing that has been done in that direction.

" Take flower of sulpMir, hromine^ and arsenious acid in the
proportions of 8, 10, and 12 respectively by weight. Dissolve the
sulphur in the bromine with gentle heat in a thinnish test tube
about six inches long. Over a small Bunsen jet add small
portions of the arsenious acid, boil and let the condensed
vapours of the mixture cool and fall down the sides again. Be
very careful that these do not escape. If none of these have
escaped, the proportions given will be correct, but, if they do
escape, probably a spot more bromine will have to be added to
keep the mixture clear.

No mechanical directions can be given beyond these. Success
•is very much like that of a cook in his preparations, and the
eye and understanding must regulate the proceedings. When
made the mixture should be about the consistency of toffee and
much the same in appearance. It should be handled with a
piece of platinum wire. The more arsenic the better, and a
grain or two of the metal itself may be coaxed in towards the
end 'SO long as the mixture remains clear. If properly made
this will last, so far as I know, for ever."

124

The Senate of the University of Dublin met on Tuesday,
June 14th, to consider the proposals of the Board to confer
honorary degrees on a number of distinguished men, in connec-
tion with the tercentenary celebration. The graces were passed,
and amongst the names of those selected for the degree of
Doctor of Sciences, we note with pleasure that of the Rev^
William Henry Dallinger, London.

NEW BOOK.

" The Essentials of Histology, Descriptive and Practical, for
the Use of Students." By E. A. Schafer, F.R.S., Jodrell Pro-
fessor of Physiology in University College, London, Editor of
the physiological portion of Quain's " Anatomy." Third
edition, revised and enlarged. London : Longmans, Green,
and Co.

This book, well known as a text-book for medical students,
will be found a most useful book for microscopists generally,
whatever subject they may have selected for special pursuit,
for no work could give them a sounder knowledge of the
principles of histology, which would be invaluable in almost
any branch of microscopic work, and would also help to an in-
telligent interest in the work of others and in the progress of
microscopical science.

The work is arranged in a series of progressive lessons. The
edition now before us contains much additional matter, is illus-
trated with upwards of 300 carefully executed engravings,
many of which are new, thas bringing it well up to date, and
also, in an appendix, ample instructions for hardening, cutting,
and staining sections, and mounting for examination or
preservation.

rouPTi.Q.M.C.

Se-IIWBPl I

RT.Lewis eLoLnatdfil

"WesbjN^ewrna-XL litk.

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D. J. SooiirfleLi. daL

"West^jrewxas-j-i li1jL

The Physiology of Monstera deliciosa.

By Henry W. King.

Plates VI. and VII,

(Head June 17 th, 1892).

The aroids to which this plant belongs are essentially a
distinct class, the largely developed bract enclosing the
organs of reproduction forming a feature that separates them
from all other forms of vegetation. They are principally
natives of the hotter climates, though there are some which
inhabit the more temperate climes. The former often attain to
considerable size, and seem to scramble among rocks and trees,
to which they find support by means of their long, pendulous,
aerial roots, that also absorb. the moisture rising from the damp
earth or subterfluent waters. Those inhabiting the colder and
dryer climates are principally herbaceous, and do not attain to
large proportions.

A strong acrid principle seems to pervade nearly the whole
order in a more or less marked degree. Through it some are
rendered exceedingly poisonous, the most remarkable example
being the dumb cane of the West Indies and South America.
Dr. Lindley states that this species "when chewed has the
property of swelling the tongue and destroying the power of
speech." Dr. Hooker also relates that a gardener " incautiously
bit a piece of dumb cane, when his tongue swelled to such a
degree that he could not move it ; he became utterly incapable
of speaking, and was confined to the house for some days in
the most excruciating torments."

But the majestic plant, Monstera deliciosa, is free, as its
name implies, from the very poisonous principles just referred
to, at least so far as the fruit is concerned, which has a great
similarity of flavour to a pine-apple. It is a native of Mexico,
and luxuriates in a moist atmosphere, where it grows among
the tropical vegetation, throwing down long, pendulous, aerial

JouRN. Q. M. C, Series II., No. 32. 9

12C) U. W. KIN(i ON THE I'lIYSIOLOGY OP MONSTERA DELICIOSA.

roots, that cling to rocks and the bark of trees as they ramify
from crevice to crevice in their search-like imjDiilse for moisture.
The dimension it attains in a natural state is probably very
considerable, as every node has a partially independent
existence, developing from the upper surface the broad,
divided, and perforated leaves, and from the under surface
the roots, thus giving to the plant the power of establishing
independent individuals with all the specialized functions
characteristic of the plant, the same as one developed from a
seed ; implying that * the plant is capable of multiplying its
individuality from the germ that originated the plant. So that
injury to the stem of the plant, caused by the grip of its own
roots or crushing by falling rocks through subsidence of the
earth, is an advantage to the species, by causing a multiplied
origin of the vitality, and more, a multiplied sphere for the
action of crossing by fertilization from flower to flower of the
strongest and best plants, the soils and conditions can develop
for maintaining or improving the excellence of the species,
for this node development and germ development of the plant
aims at the one object — the improvement or maintenance of the
species. Given a seed which has developed to a plant, the energy
of the seed does not stay, but goes on developing to its utmost
capacity by the plant dividing into many, each individual
plant searching for the best soil and conditions that it may
grow and produce a strong flower. Those plants producing
the largest, the most attractive flowers are the most likely to
receive the visits from insects, thus crossing only the higher
and the most perfect forms.

The stem of the specimen from which these observations are
made was about three inches in diameter, of a brown colour
upon the older parts, and shading to dull olive green where it
is less matured, while the fresh-growing portions were of an
almost white hue. The surface of the stem is smooth, with the,
exception of certain protuberances or glands, to be found also
on the petiole and the peduncle. These glands are composed
of simple cells, and are evidently destined to keep open a com-
munication between the deep-seated parts and the exterior, as
the bark is of a close, thick nature. It is interesting to observe
the rigidity which these cellular protuberances assume, yet
they are merely thin, simple, transparent cells, and acquire

H. W. KINO OX THE PHYSIOLOGY OF MONSTERA DELICIOSA. 127

their apparent hardness by the pressure of the fluid within
them ; they become a series of distended bladders, and while
the cells of the tissue surrounding them are capable of deposit-
ing colouring and other substances, these cells remain clear and
thin-walled, distinct organs, like reservoirs of moisture for the
tissues to draw from, to enable them to act in variable con-
ditions of the atmosphere.

Developing from the lower half of the node immediately
beneath the axil of the leaf the roots are at first a faint green,
almost white as they burst their way through the bark of the
stem, swelling as they increase in length, darkening in hue as
they mature, except the growing point, which, while above
ground, remains greenish white. They continue to descend in
search of moisture and food, sometimes trailing serpent -like
along the surface of the earth for some yards, and often
dividing and sub-dividing until they form masses of twisted
and contorted fibres, some of which attain half-an-inch in
diameter, and hard as the bark of the stem. Many roots which
I have seen clinging tenaciously to cork bark throw out along
their surface multitudinous sucker-like expansions, such as
are to be seen upon the clinging roots of many climbers, as ivy,
only closer, more like velvet pile, while others plunge direct
into the earth. Thus, according to conditions, each root is
capable of accommodating itself to the state most conducive to
its well being. The proportion of root growth to that of the
stem and its other appendages is very great in Monstera as
compared to plants which require roots mainly for nourish-
ment, and not as in Monstera deliciosa, for repetitions of
support to enable the plant to ever raise itself into light
and air above the growth of tropical vegetation.

In structure the root is principally composed of irregular
cylindrical cells, strengthened and supported by long cells of
woody fibre, the latter giving to the binding and clinging
roots that strength and tenacity and means of rapid convey-
ance of fluid so necessary to a plant of this description.
Coursing through the centre are a number of scalariform ducts,
and arranged outside these in a circular growth are a series of
pitted ducts. The walls of the cellular tissue of the centre are
thinner than those of the cuticle, which become thickened by a
brown deposit, and it is this which gives the hardness and

J '28 H. W. KIN<^ ON yilK PHYSIOLOGY OP MONSTRRA DELICIOSA.

strength to the older roots. The free-growing end of the root,
known as the spongiole, develops by the growth of simple
spherical cells, which are gradually pressed outwards by others
forming, and as they are forced to the exterior they become
elongated and form the cylindrical cells, which, in due course,
receive the deposit referred to, and become hard and capable of
I'esisting great pressure.

The stem is composed largely of oblong cells of cellular
tissue, similar to those found in the root ; they are the first
series of the cellular structures connected with the cuticle and
rough prominences, then groups of spiral vessels imbedded in
woody fibre, and next to these scalariform ducts, along the
sides of which run disconnected bands of raphides, individually
of a long needle shape, while interspersed in the cellular
structure which follows are a number of another kind of
raphides, which form clusters of square-shaped crystals, in
spaces round which the cellular structure often radiates.
Similar forms of raphides frequently occur in the cells them-
selves, and it is possible the apparent spaces were formerly
cells in which the raphides were formed, and whose cell walls
have become ruptured and absorbed, causing a modified
arrangement of the cells surrounding them. Pitted ducts,
three to four cells broad, pass down by the side of this
formation. Both the stem and root are free from laticiferous
tissue.

The upper half of the node may be seen to swell, and
gradually the sheath enclosing the leaf bursts through the
stem in a similar manner to the bursting of the root from the
lower half, developing out from the growing point of the stem
about 18 inches, at the sa.me time slowly changing from a
cream colour until it acquires a rich green ; then the leaf blade
which is developing contiguous to, and in the same perpen-
dicular line of growth as the petiole, bursts the sheath sur-
rounding it at the free end, and as the leaf blade continues to
mature it uncoils, at the same time the sheath splits, and
falling, suspended by its base, turns brown, shrivels, and is
finally cast off the plant, leaving exposed the cavity in the
under side of the petiole that helped to protect the blade-
Meanwhile the leaf, continuing its growth rapidly, unfolds the
fi^esh verdure of the beautifully perforated and divided lamina,

U. \V. KING ON THE PHVSIULOGV OF MONSTEKA DtlJCloSA. 129

which is raised horizontally and at a right angle to the petiole
by means of the petiole at the point of attachment to the leaf,
becoming flattened and corrugated, so that the corrugations can
fold back upon one another on the upper and stretch on the
under side, forming, as it were, a stop hinge, thus enabling
the blade of the leaf to rise and, spreading, perform its
functions. The cells across the joint approach to a hexa-
gon in transverse section, but as they recede from it
they become more cylindrical. Similar protuberances are
developed on the convex side of the petiole to those found on
the stem, but none are formed upon the concavity of the
petiole that sheltered the lamina. A longitudinal section of
the petiole shows a series of oblong cylindrical cells, the outer
layer coming in contact with the cellular prominences. Many
of the oblong cells contain clusters of square-shaped raphides,
but these are most numerous in the small hexagonal cells in
the node. Passing at intervals between the oblong cells are
large fibre cells and bands of needle-shaped raphides. Spiral
vessels, consisting of four to five united threads, course along
at intervals in the parenchyma structure, surrounded by bands
of small woody fibre cells. Laticiferous tissue is sparingly
distributed along the stalk. The general structure of the
petiole is (including the spiral vessels and raphides) continued
through the mid-rib and smaller veins of the lamina. The
epidermis of the latter consists of five to six-sided cells, cover-
ing loosely-arranged parenchyma ; that, with numerous inter-
cellular spaces in it, forms the substance of the leaf. Stomates are
distributed over its under-surface, but none exist upon the
upper surface away from the veins, upon which a few are to be
found. The stomates are formed of two kidney-shaped cells,
whose concave sides are opposed to_^one another, and the cells
surrounding them are irregularly six-sided. The limiting cells
of the membrane of the apertures in the leaf become thickened
similar to the cells forming the limit of the growth of the
edge of the leaf. These apertures or perforations are a part
of the organization of the plant, gradually moulded from the
germ, as any other organ of the plant is, and in a measure
essential to the life of the plant. They are an advantage to the
plant by allowing the moisture and rain to drip through the
apertures to the roots growing beneath them, or the roots

130 H. W. KING ON THE PHYSIOLOGY OF MONSTERA DELICIOSA.

would be kept dry were the leaf a plain expansion, void of
sutures and perforations, because the leaves, when growing,
have a tendency to overlap one another, similar to the tiles on
a roof. So that, were it not for these perforations, the broad,
bright verdure, intended to nourish and be a means of support,
would, instead, be the means of cutting off a large portion of
the fluid supply to the plant.

Growing upon a peduncle axillary to the leaf, the large and
beautiful inflorescence may be seen, partially protected by a
single bract or spathe, which forms one of the most striking
features of this plant. The flowers consist chiefly of a pistil
and stamens, arranged in a regular spiral round the spadix.
Previous to its expansion, the spathe is coiled round the
spadix; it is then a soft, pale green colour, which gradually
acquires a hue approaching ivory white when fully matured,
and acquiring an additional beauty by the hexagonal markings
of the pistils, which were impressed on it by the force of
growth in the spadix before uncoiling, and which are retained
during its vitality. The duration of the flower in a hothouse
is about fourteen days ; it is possible that the duration in a
state of nature is much less, as fertilization would take place
with greater facility. The spathe is composed of cellular
tissue, irregularly hexagonal in form, interspersed with spiral
vessels. It is remarkable for the amount of laticiferous tissue
that ramifies throughout its whole structul-e ; intercellular
spaces are numerous, but very little woody fibre is formed in it.
The cuticle is well-supplied with stomates, which take the
same form as those upon the leaves.

The structure of the peduncle is similar to that of the leaf-
stalk or petiole, consisting of the spherical cells forming the
rough prominences, oblong cells, bands of woody fibre surround-
ing spiral vessels, as represented in the section of the leaf-stalk.
The rachis is a continuation of the peduncle. Its cellular
structure becomes larger, owing probably to a stimulated
vitality causing the cells to appropriate more nutriment from
the circulating fluid, which is increased by an extra number of
spiral vessels distributed through it, and by the thinness of the
cell walls, which do not become thickened by deposits as in the
more lasting parts of the plant, so enabling the fluids to
permeate with greater facility.

H. \V. KING ON THI'] ['HYSIOLOGY OF MONSTEKA DKI.ICIOSA. 131

The pistils grow in a perfect spiral, close together round the
spadix, and — according to the pressure of growth against one
another — become more or less hexagonal in form and taper
to the base or point of attachment to the spadix. The stigma
is the exposed broad, flat expansion, pierced in the centre with
an elongated aperture leading to the ovary. The ovary and
stigma are the only parts to be distinguished during its
inflorescence, and its microscopic structure shows no demar-
cation between these parts. But when the fruit has arrived at
maturity, the cellular structure throughout has become greatly
enlarged, and, at a certain stage, the fluid supply to about the
upper-fourth of the pistil appears to cease, the result being
that that portion becomes of a dry, spongy nature, and having
served the two-fold purposes of a conductor to the ovary and
a shield to the germ, which it helps to enclose, is thrown off as
a shell from the whole spadix. This cast-off portion is probably
analogous to the style and stigma, that remaining being the
fruit that is destined to nourish and protect the seed developing
in the ovary.

The stamens are arranged against the sides formed by the
contiguous pistils, and are usually (but this is liable to
variation) two to each side of each pistil, making twelve
stamens round each segment. The stamens are not seen when
the spathe first opens, but by a peculiar growth the spadix and
the pistils elongate at the same time, without the pistils
becoming larger in diameter, the result being that a vacancy
is caused between each side of the pistils, sufficient to enable
the stamens to grow beyond the stigma and expand.

The stamens have bilobed anthers supported upon a very
broad, flat filament attached to the base of the pistil, in every
way well-adaj)ted to their position of growth.

When the stamens first appear above the pistils, the anthers
are in a line with one another, but, as development proceeds,
the bases of the anthers separate and diverge, and the upper
portion bulges as if by a pressure from within, ultimately
rupturing with a broad, elongated aperture, out of which the
pollen gradually streams. The development of the pollen
continues for some time after the first-formed has passed the
rupture of the anther, and forces outward until the pollen
hangs from each anther of the spadix like miniature catkins, of

132 H. \V. KING ON THE PHYSIOLOGY OF MONSTERA DBLICIOSA.

a yellow colour and many times larger than the anthers them-
selves. The pollen in this condition is as smooth, round-
flattened bags, pressing against one another and adhering, but
if isolated and moisture be applied, they immediately swell to
an almost spherical form. The pollen falls to the base of the
spadix and is collected by the spathe. At the base of the
spadix the pistils and stamens become aborted, the former
secreting a greater quantity of honey than the perfect pistil ;
this accumulates in globules, that trickle down the spadix
among the pollen collected there. It would form a ready-
arranged collecting spot for those bees which collect pollen for
the use of their young, as, in oar own country, mason bees do
in the making of the so-called bee-bread. And it would seem
possible that these pistils became aborted by their continued
non-excitement by foreign pollen, through the accumulation of
the plant's own pollen, preventing its access to the pistils.

The upper surface of the stigma consists of conical-shaped
cells, pointed at the free growing extremity, pale in tint towards
the periphery, but as they approach the centre assuming a dark-
brown colour. The cells beneath the epidermis are almost
colourless and much more loosely arranged, in consequence of
which they vary in the outline, being near the centre of an
oblong shape, but as they recede from the axis they become
oval, and at places where the side pressure of growth is not so
great they retain their almost spherical form. Apparently
coursing indiscriminately through this cellular tissue are a
number of woody fibre cells which attain to very large dimen-
sions in this part of the plant, particularly in the mature con-
dition, when they probably act an important part in conveying
fluid, at the same time forming strengthening bands binding the
cellular tissue together. Through the intercellular spaces the
ramifications of the laticiferous tissue may be seen divided and
subdivided in all directions. From the base or point of attach-
ment of the pistil to the rachis at the position e (Fig. 8, Plate
VII.), spiral vessels may be traced through the cellular structure
being surrounded by bands of woody fibre of a smaller and
narrower kind than those independently distributed through
the cellular tissue.

It would seem that cells start with a certain formative energy
which impels the development of the cell until its utmost

H. VV. KING ON THE PHYSlOLOCxY OF MONSTERA DEIJCIOSA. 133

capacity is reached. But when two cells of a like formative
energy grow in close relation with one another, the stronger of
the two appropriates the formative material to its own structure
from the one with the least. The large woody fibre cells are
situated among the parenchyma cells, whose function is different,
the formation of chlorophyll, secretions, etc., and therefore
these woody fibre cells go on developing to the full capacity of
their formative energy, having no other kind of cell to influence
their non-development. Not so with the smaller kind of woody
fibre cells ; these grow with cells of a like energy and are stayed
in their growth by the appropriations of the spiral vessels, so
producing the two kinds of woody fibre cells, the large and
small.

Raphides of two kinds exist in the pistil, the long, slender,
needle shaped, grouped in bands extending more or less through
the centre, and clusters of angular crystals to be found prin-
cipally in the cells beneath the cuticle of the stigma, though
some are to be found in the deeper seated cellular structure.
The aperture of the stigma leads through a tube, lined with
cylindrical cells, into a double chamber, again divided by a loose
cellular division, so forming foui' compartments in which the
four ovules grow. From the base and sides of the ovaries
growing inwards are a number of elongated cylindrical cells,
that developing almost fill the cavities with a thick stroma of
semi-transparent hairlike processes, forming an elastic and
adaptive cushion for the ovaries to partially rest and grow upon.
It is possible this quick growing cellular structure, imbedded as
it is in the fleshy part of the pistil, may increase the tempera-
ture of the cavity, at the same time keeping the contents moist,
both conditions promoting the growth of the ovule. They may
also form a channel of nourishment to the pollen thread, while
it lives and develops there as an independent growing organism,
for the membranes covering these cells and the pollen thread
are extremely thin, admitting of ready permeation of the circu-
lating fluid. The ovules are of a pear shape form, a yellow
colour, and coated with a smooth membrane. They are attached
to the placenta by an elongated hilum rising from their inner
side near the narrow extremity, with the greater diameter up-
wards, the foramen being at the lower and narrow extremity.
Each ovule consists of two coats, the primine and secundine,

134 H AV. KING ON THE PHYSIOLOGY OF MONSTERA DELICIOSA.

the former being traversed by spiral vessels passing through
the hilum to the upper extremity o£ the ovule. The aperture
of the foramen passes, narrowing upwards, to the nucleus,
the latter consisting of an aggregation of nearly spherical
cells of a larger size than the cells composing the primine and
secundine.

In the younger ovules I have examined, the nucleus or germ
is buried higher in the ovule, but in the more advanced growth
it descends to the foramen, through which in the mature forms
it protrudes beyond, and in some instances the secundine coat
is also exposed beyond the exostome of the primine. This action
in the plant is of great importance in securing the fertilization
of the germ by the pollen thread, for if the germ were not thus
exposed in the ovaries the possibility of their impregnation
appears to be very remote.

The pollen is probably brought from the anther of one plant
to the stigma of another by the agencies of insects, which are
attracted by the honey and the colour of the spathe. They
would first alight upon the spadix to collect the honey exuding
from each pistil, and in passing downwards would leave behind
upon the stigmas the pollen that had adhered to them while
collecting at another flower. Many may collect the large
quantity of pollen developed to form the so-called bee-bread,
and also in so doing would readily bring about the fertilization
so necessary for the favourable perpetuation of the species.

The ovule being fertilized, the honey secreted on the stigma
hardens to a horny consistency, preventing at the same time the
ingress of insects to the ovary, and the evaporation of moisture
from it. The fertilized germ, protected as in a sealed chamber,
develops to a seed, nourished by the secretion of the fruit sur-
rounding it, until matured, when the secretion ceases, the
cellular structure gradually dries and cracks, and the seed hangs
ready for wind or bird to carry it to a suitable germinating
spot, where it may continue the development originated in the
ovule, to the perfected life of the plant. The emanations of
that growing life throb out intangible as a wave of light. We
feel the presence of that life and the swell of the beautiful
that dwells there.

H. W, KING ON THE r-HYSlOLOGY OF MONSTEKA DELICIOSA. 135

Explanation of Plate VI. '

Fig. 1. — A branch of Monstera deliciosa. a. Aerial roots, b.
Petiole cut across showing concavity, c. Inflorescence
with spathe coiled round, d. Spathe open showing
spadix and spirally arranged pistils. e. A leaf
uncoiled preparatory to assuming the horizontal
position as in /. g. Corrugated joint of petiole and
lamina, h. The natural perforations.

„ 2. — Pistil and stamens from spadix. a. Aperture of stigma.
h. Immature stamens arranged round pistil.

„ 3. — Pistil with matured stamen discharging pollen.

„ 4. — Stamen as seen when first appearing above pistil.

„ 5. — Stamen matured showing divergence, bulging and
splitting of anthers.

, 6. — Diagrammatic section of pistil, a. Upper fourth, which
scales off the whole of the pistils of spadix when
period for fertilization is passed. The centre repre-
sents a typical ovary, style, and stigma, and probable
analogy of cast off portion to a style and stigma.

Explanation of Plate VII.

Fig. 1. — Transverse section of root. a. Irregular cylindrical
cells, h. Pitted ducts, c. Scalariform ducts.

„ 2. — Growing end of root. a. New formed spherical cells,
6. The same, elongated and strengthened by deposit.
c. More enlarged cylindrical cell, showing deposit of
colouring matter over the cell wall.

„ 3. — Longitudinal section of stem. a. Cells forming glan-
dular prominences. h. Irregular cylindrical cells
with raphide crystals in some. c. Small woody fibre
cells. d. Spiral vessels, e. Scalariform vessel. /.
Cluster of needle-shaped raphides. g. Pitted ducts.

,, 4. — Longitudinal section of petiole, a. Glandular promi-
nences. 6. Cylindrical cells, c. Small cells of woody
fibre, d. Spiral vessels, e. Large cells of woody
fibre. /. Needle-shaped raphides. g. Square-formed
raphides. h. Laticiferous tissue.

186 H. W. KINg'oN the physiology of MONSTKKA DELICIOSA.

Fig. 5. — Transverse section of petiole.
,, 6. — Longitudinal section from spathe. a. Irregular sided

cells of parenchyma, h. Intercellular spaces, c.

Anastomosing laticiferous tissue. d. Small woody

fibre cells, e. Spiral vessels.
,, 7. — Cuticle from spathe.
„ 8. — Section of pistil, a. Stigma, h. Style, c. Ovaries.

d. Ovules.
„ 9. — Section of ovule, a. Primine. h. Secundine. c.

Germ. d. Spiral vessels.
„ 10. — Portion of more advanced ovule showing secundine

and germ protruding beyond the primine of ovule.

137

Observations on the Habits of Some Pond Life prom the
West Indies.

By Henry W. King.
Plates VIII. and IX.

(Read September 16fJi, 1892.)

Some months ago I suggested to a friend travelling to the
West Indies the possibility of bringing pond life from there to
this country alive for observation. Knowing the extremes of
heat and cold and altered conditions in which lower life in
general can live, it seemed quite feasible, and my friend, a Mr.
Inglis, kindly offered to bring some with him on his return
journey.

I received from him two jars containing dippings from Port
Limon and the Island of Colon.

Flag plants grew there, and shrubs and trees flourished by the
water's side, providing shade and shelter to alligators bathing
in the waters. Naturally favourable spots for microscopic life,
it was not surprising some interesting forms should be found
living and preying either upon the vegetable or the excrement
and remains of animal life abounding there.

The waters were clear, with sedimentary matter at the
bottom, that from Port Limon having by far the most, and was
of a darker colour than that brought from Colon. All the
water plants in both dippings were dead and discoloured,
through decay, but the forms of some were partially retained,
and the remains of grass stems and roots could be distinguished
in the former dipping, while in the latter I have no doubt there
were the remains of plants of a species of Chara or Nitella.

A glance with a lens at the waters at once revealed their
animated condition. A Cypris would glide with alternate
opening and closing valves over the sedimentary refuse, and
small worms and Rotifers were swimming freely through the
water and among the remains of vegetation from Colon, while

138 H. W. KING ON POND LIFE PROM THE WEST INDIES.

Cyclops swam, with its well-known series of jerks, and larvse
of a species of Tipala wriggled their way in the water brought
from Port Limon.

Thus both waters appeared to have a fully-inhabited look
about them. The many weeks' oscillation on the sea, the
changes of temperature, the altered influences of conditions
generally, seeming to produce bat little harm upon the life in
the waters, other than upon the higher life of the water plants,
which were unable to adapt themselves to the changes, and
perished, though the spores of Algge have retained their
vitality, and are now germinating among the vegetal decay and
extending their long green cells.

One of the most numerous forms of life in the water from
Colon is a worm of the curious form figured (PI. IX., Fig. 1).
It lives about the stems, rootlets, and refuse in the water, among
which it glides, the hair-like tufts from each annulose aiding
it in its motion by fixing on the materials on which it is moving,
and the muscular bands proceeding in a zigzag line along each
side of the animal, by contracting, causes a serpentine move-
ment of the body. Situated at the back of the head are two
tufts of hairs which have a very different function to the hairs
running along each side of the animal. They do not take part
in progression, but, with a strong, nervous impulse, are in a
perpetual tremulous vibration when erect, like the antennae of
many insects, notably the Ichneumons. They are longer than
the other hairs on the body, and are capable of being folded
down, either over the back or forward over the head, according
to the direction in which the creature is moving.

The head is tapering, and ends in a long trunk of a very
flexible and sensitive nature, capable of being curved or coiled
in any direction. The animal uses it mainly for thrusting
round stems to aid in drawing itself along, or when the creature
is in a vegetable tube, to assist it in making a way, clearing
obstructions, and generally feeling its course, and is useful also
to assist it up a tube by casting the trunk over the aperture,
and assisting in drawing itself out.

It is curious to observe these creatures making their way
along a vegetable tube, feeding now, and then gliding a little
way, resting a time, then gliding to fresh provender a little
further ofP, in a most happy and contented mood, and living in

H. W. KIXG ON PONJ) LIFE FROM THE WEST FNDIES. 139

this manner sometimes a couple of days in one tube. Some-
times they partially protrude from the tube, thrusting the pro-
boscis in all directions, as if to find the whereabouts of other
stems, and then, as if fearful of danger, darting back in the tube
as a Mellicerta will do, as though quite conscious of the pro-
tective nature of the acquired tube. In doing so, the head is
often drawn in so as to throw a fold of the integument partially
over it. When feeding upon the vegetable or animal matter
softened by maceration in the water, the trunk is mostly curved
back over its head, that the mouth, situated upon the under
side of the head, near the base of the trunk of the animal, may
the better reach the food (Fig. 2, PI. IX.).

The aperture of the mouth is opened like lips, and the
oesophageal bulb (Fig. 2, a, PL IX.) is thrust forward beyond
the lip-like opening, and by a series of quick thrusting out and
retractile motions of the cesophagus, the food is torn from what
it is adhering to, and quickly, passes into the stomach by the
relaxation of sphincter muscles at the larger end. After
remaining there but a very short time, the food is released by
other sphincter muscles at the base of the stomach, and it
passes into the intestine, through which it is quickly carried
by the peristaltic action of the muscles composing its walls.
When the animal is actively engaged in feeding, the remains of
the food are expelled in about seven minutes from the time it
enters the gullet, to be preyed upon b}^ small Rotifers, Diatoms,
and Monads.

These worms, wallowing in numbers among decaying and
decayed matter, and nearly always feeding, must have a power-
ful influence in keeping water pure in a tropical climate, by
quickly devouring the refuse falling in the water from animals,
insects, and vegetation, seeming, by the quick and almost per-
petual action of their digestive system, to change and so prepare
the refuse in the water that it may become adapted as food for
lower life living there.

Associated with these worms, living among them, and some-
times utilizing vegetable tubes adapted by the worms, is a
curious active little Rotifer, very numerous in the dipping from
Colon.

This Rotifer, which I propose naming Fercularia tubiformisi
has a broader head than the trunk, tapering slightly to the

140 H. W. KING ON FOND LIFE FROM THE WEST INDIES.

back, with two short horn-like processes at each side, capable
of slight contraction and extension. It has one ruby-coloured
eye, situated upon a stylif orm process of the head. The outlines of
the trunk follow nearly horizontally from the head to about three-
fourths of the length of the animal, where the body is suddenly
reduced in size, as each successive ring of the integument
becomes smaller than the preceding, this annulous formation
enabling the animal to curve and bend in any direction, as each
larger ring of its structure works over the smaller. The tail
bifurcates from the end of the body, is telescopic, and ends in
two powerfully-formed, articulated, toothed claws, curved in
outline, and very useful to the animal's mode of life. The
animal can at will close the two bifurcating branches of the
tail, with the claws attached, so that they lay in the same line
but with a downward curve, as in Fig. 2, PI. VIII. Or it may
spread them rigid, as in Fig. 1, PI. VIII., with the clawlets of
the claws elevated or depressed, according to the requirements
of the animal. This control over the clawlets is a very im-
portant one to this Rotifer, enabling it to use each claw of the
tail as a simple tool by thrusting it into substances without the
clawlets forming an obstruction, which they would do if they
were fixed and always erect. Again, they are useful as a com-
pound tool when they are elevated, by forming a notched hook,
stronger and better adapted for loosening materials, and also,
as in Fig. 5, PI. VIII., for drawing earthy particles to their
tubular dwellings, which they could not so well do if each claw
was a plain, smooth hook.

They live almost entirely in either appropriated tubes formed
by the hollow stems of aquatic plants, or burrowings of the
worms aforesaid, or tubes constructed by themselves from the
flocculent sediment at the bottom of the water. When forming
a tube, it is interesting to notice how the animal forces its head
into the decaying vegetable matter or refuse, and having made
a hollow about half the length of the creature, and as if the
matter would not yield further by this mode, it turns round,
with its tail in the burrow and the head outside. Then, fixing
its notched tail, over which it has considerable control, in either
side of the burrow, it moves backwards and forwards, loosening
the materials as it does so, and gradually forcing its way in, at
the same time pressing the aides outwards suflficiently to enable

If. W. KING ON POND LIFE FROM THK WKST INDIES. 141

it to move up and down, sometimes incessantly drawing earthy
particles by means of its tail, to fill up vacancies should they
occur, or add to its dimensions when required.

The tabes thus formed are sometimes only three or four
times, at others eighteen to twenty times its own length, or
even longer. They are composed of fine earthy particles ad-
hering without regularity to one another, often with diatoms
and flocculent matter entangled among the particles, and pro-
bably held together by some viscid secretion of the animal, in-
soluble in water. Their forms are varied, often quite straight,
at other times curved, some are turned at sharp angles, or
carried crossways through other tubes not inhabited.

In all cases the tubes are constructed to enable the indus-
trious creature to swim easily up and down them. Of this they
are very particular, any obstruction by bulging out or pressing
in occurring by other life coming in contact to damage the
tube is at once made right by the Rotifer fixing its claw-like tail
or foot to both sides of the tube and jerking backwards and
forwards, by so doing again forcing the walls of the tube out-
wards or inwards, as the case may require, to their former
position. Should some of the small earthy particles have been
moved away, the Rotifer will then thrust itself out of its tubular
dwelling backwards, with its head inside (and, I believe, fixed
with its small horn-like processes), and then draw^ the particles
back again in position by means of its claws.

It is a remarkable power these minute animals have over this
forked tail of feeling for and selecting particles suitable to their
purpose when the so-called eye-spot is hid and buried in the
tube, and therefore rendered useless in this condition for action
outside the tube.

When the tube appears completed and some loose material
has been drawn to the openings to close them, the Rotifer may
be seen to swim backwards and forwards, coursing regularly
along, mostly going the entire length of the tube, though some-
times stopping short as if to feed, then turning, will go back
again.

The sense of adaptability in these Rotifers must be largely
developed, as they sometimes take possession of vegetable tubes,
and adapt them to their requirements by building a wall with
small particles of refuse across the tube (see c, c, Fig. 5, PI,

JouRN. Q. M. C, Series II,, No. 32. 10

142 II. W. KING ON P0N1> J.IFK FROM THE WEST INDIES.

VIII.), as if to reduce the size, and so save themselves the
labour of constructing an entire tube.

On one occasion I observed another of the same species enter
and pass partially down the tube while the owner was at the
other end. When they met both became excited, darting back-
wards and forwards at one another with a rapid motion ; but
the trespasser soon turned and quickly fled from the tube and
swam away, the pursuer stopping at the end of its tube, and,
after protruding its head a little way, turned, and drawing
some fine particles of earthy matter with its claws to its
dwelling, it closed the aperture again, and commenced journey-
ing up and down the tube as before.

I have watched one live in a single tube for several days,
coursing incessantly up and down it, never seeming to rest
either at night or d?ij. As they only leave their tubes that
they may go elsewhere to adapt or construct another, they are
very rarely seen swimming free in the water. When they do
they are extremely restless, and always eager to seek the refuge
of a cluster of earthy particles or rootlets, into which they try
to burrow. * What the cause may be that induces them to leave
one tube, that has cost them so much labour to make, or adapt
to their requirements, for another tube, I am unable to say,
unless it may be the necessity of obtaining food, as they seem
to feed upon something inside their dwelling, so that when
this is devoured hanger necessitates them seeking another
tube for the twofold purpose of protection and a feeding ground ;
or it may be that ova are deposited, and when that is the case
the parent leaves the tube it was in, for the use and protection
of its coming oifspring.

On one occasion I tried the experiment of placing one on a
glass slide and allowing the water to evaporate, and after
throwing itself into various positions, as if trying to find a
means of making itself as small as possible, the Rotifer finally
rolled itself into a spherical mass, with its extremities coiled
round it, in which condition the carapace-like nature of the
dorsal part of the animal may be distinctly seen. Having kept
it thus dried up, wrinkled, and apparently dead for over an
hour, I covered it again with some water, and in about two
hours it gradually began to revive, and ultimately assume its
normal condition.

H. W, KING ON POND LIFE FROM THE WEST INDIES. 148

Rj these Rotifers having the capacity of retaining their
vitality after being dried up, the species is adapted for a very
wide distribution, for should the ponds in which they live be-
come dry, as frequently happens, the wind would waft these
dormant spheres of life, like dust, from one locality to another,
and when falling on suitable spots, and conditions being favour-
able, would become reanimated and originate fresh centres of
development.

Another allied species was numerous in the water from Port
Limon, but differing from the one just considered by having an
orange-coloured body ; this, however, may be mainly due to the
different kind of food and the water in which it lives, as cater-
pillars and other life are frequently modified in colour by their
diet. Whether from a different habit or owing to their large
numbers, they appeared to be more associated in a colony, I
had as many as five under the microscope at a time, and the
tubes seemed to be more anastomosed together and crossing one
another in various directions, forming a small matted mass.
From the thicker, more opaque nature of their tubes it was not
so easy to observe their habits as in the case of the preceding
kind. This difference in their dwelling was probably due more
to the different materials used giving them an altered aspect
than from any variation of instinct action in their individual
construction.

Both this variety and the former were very unaffected at
sudden sounds and shaking, a different characteristic to that of
most free swimming Rotifers, no doubt due to a sense of security
felt in their closed dwelling.

A Rotifer (Fig. 6, PI. VIII.) living in and also utilizing earthy
matter for a protective purpose was at home in the water from
Colon. This animal usually imbed^ itself in the earthy matter
in the water aggregated either among weeds or at the bottom.
The lower portion of the body imbedded is curved, as it has
so small a foot that it would be useless in retaining it in
safety in so light and flocculent material were it not for this
modified shape of its body forming, as it does, a larger surface
for resistance. When disturbed it draws itself in below the
surface, and the opening through which it passes in and out
closes over it, so that it becomes buried until it feels the
threatened danger has gone, when it may be seen to slowly un-

144 II. W. KINC (»N I'ON'D LIKK FROM THhl WEST INDTKs.

earth itself by pushing forward its very long horn and tapering
head (Fig. 9, PI. VIII.), with two ruby-coloured eyes, and
cautiously expanding its cilia to vibrate like revolving wheels.

This Rotifer, unlike the last-described, but like most of the
larger wheel-bearing kinds, is very sensitive to vibration and
sound. It sometimes assumes a quiescent form when away
from earthy protection, among the stems of water plants, and
will remain a considerable time in this condition, apparently
resting (Fig. 8, PI. VIII.) ; at another time it bends its body over,
reclining in a grotesque manner (Fig. 7, PI. YIII.). May not
this habit be a protective one, a simulating a worm, a growing
alga, or some other form of life different to its own, so that
other life preying upon it in its normal condition would not be
so liable to recognize it in its assumed form ?

While these brief and fragmentary notes of the habits of the
few forms of life living and carried in the small vessels of water
given to me from the West Indies illustrate the ever-acting law
of adaptability of life — and more in the case of the tube-dwelling
Rotifers where they develop the simple action of adaptability to
a higher function, that of construction, and where they not only
adapt, but from materials build repetitions of the tubes that
form their habitations — there are other forms in the water of
Rotifers, Vorticellfe, and a variety of life interesting alike from
their forms and habits, which time has not enabled me to study.

Explanation op Plate VIII.

Fig. 1. — Fermdariatubiformis^ U.S. yeiLtended. a. Ruby-coloured
eye supported on elevation. bb. Expanding and
contractile prominences. c. Curved claws, with
articulated clawlets. d, e. Caudal muscles largely
developed in this species. /. Stomach, g. Rectum.
j. Anus. h. Pharynx, i. Pharyngeal muscles.

Fig, 2. — Fercularia tubiformis, side view partially contracted.
a. Eye. b. Expanding prominences, c. Claws.
d. Clawlets. e. Stomach. /'. Rectum, both con-
taining diatoms, gg.

Pig. 3. — Enlarged ventral view of claw. a. Showing arrange-
ment of clawlets, bb.

Fig. 4. — Fercularia tubiformis dried, showing carapace like
nature of dorsal integument.

H. W. KING ON POND LIFE FROM THE VVE^T INDIES. 1 4.0

Fig. 5. — A colony of tabular dwellings of F. tuhiformis, showing
constructed tubes and an adapted vegetable tube.
a. Extremity of Rotifer extended from tube-collecting
refuse to close aperture of tube. 6. Vegetable tube
with Rotifer swimming inside, and (cc) wall of
earthy particles arranged to reduce size of tube.
d. Accumulation of refuse closing aperture of tube.

Fig. 6. —Rotifer embedded in sedimentary refuse.

Figs. 7 and 8. — Quiescent forms assumed by above.

Fig. 9. - Head of same as when first extending.

Explanation of Plate IX.

Fig. 1.— Magnified dorsal view of worm from Colon, West
Indies, a. Tapering head. h. Flexible proboscis.
c. Vibrating hairs, d. Anus. e. Largely-developed
stomach. /, Showing natural size of worm.

Fig. 2. — Side view of head showing oesophageal bulb (a) pro-
truding beyond opening of mouth, and proboscis
thrown back as when the animal feeds.

Fig. 3. — Ventral view of head showing aperture of mouth (a).

Fig. 4. — Enlarged view of stomach, a & b. Bands of sphincter
muscles.

Fig. 5. — Enlarged dorsal view of part of body of worm, show-
ing (a) attachment of hairs used in locomotion; (6)
muscular bands partially contracted passing along
each side of animal ; (c) alimentary canal ; (d) semi-
opaque granules in protoplasm.

Fig. 6. — Vegetable tube inhabited by worm. a. Showing fold
of integument that sometimes partially covers the
back of the head of the worm.

146

On the Adinetadj:, with Description of a New Species.

By David Brtce.

Plate XI.

(Bead September 16th, 1892.)

Among the numerous species of E-otifera which I find in
washings of various mosses gathered from different localities
and positions of growth, no one form is of such general
occurrence as Adineta vaga. It is not, however, one of those
species which; so far as we yet know, are only to be found in
what we may conveniently term moss-habitats, as it occasion-
ally occurs in pond-dippings, yet in my experience invariably
in limited numbers. But in moss-washings it is almost always
present, frequently abundant, and this fact suggests that this
species, like so many others of the Bdelloida, has special
structural and constitutional characters, which enable it to
flourish better amid the conditions of life obtaining in moss-
habitats than in the open waters of pools and ditches.

As a Bdelloid, its most noticeable character is the form of
the ciliary organs. In place of the stout head and the
prominent pair of pedicelled discs bearing the ciliary wreaths,
or wheels, so conspicuous in the Philodinadae when swimming
or feeding, Adineta vaga has the ciliary wreath modified to a
mere furring of the ventral surface of a much-flattened head, a
furring which is exposed when the creature is travelling about,
by means of which it creeps, and which is not adapted for
swimming, but only for such creeping. If by chance dis-
lodged from any raised surface on which it is travelling, it
must fall through the water until arrested by the bottom or
some obstacle whereon it can again gain foothold. It must,
therefore, seek its food either on the bottom or on any surface
which it can reach without swimming. It is possible that this,
to some extent, may account for its supposed rarity, as the

I). BRYCE ON THE ADINETADJ:. 147

usual methods of collection are not adapted to secure many
bottom-feeding forms. It is more likely that its inability to
swim handicaps it very seriously in the struggle for existence
in pools and ditches, and especially in such as have but a
scanty supply of weeds, and that in such places it is actually
scarce as a natural consequence.

This same inability to swim is not, however, a serious matter
to a creature whose existence is passed where a plentiful
supply of water is only occasionally present, and would be of
still less importance where the supply of moisture is commonly
limited to a thin film covering the stems, or drops lodging in
the axils of the leaves, as is the case with many mosses.
Besides, if unable to swim, this Adineta can move along at a
rapid rate, half -gliding, half -creeping, the body, as well as the
head, being now flattened and appressed to the surface on
which it is creeping. This flattening of the head and body
enables it to travel and to feed in a thin film of water too
shallow to allow the stouter Callidinae to pass, far less to
gather food.

The modified corona is not able to attract remote food
particles, but can only gather in such as are actually within
touch, and the animal has further acquired a peculiar method
of feeding. Attaching itself by its toes, it extends itself to
full length, keeping the face applied to the opposing surface,
and gathering in all available particles, then, suddenly pulling
itself back, it again extends in a new direction, and, in this
way, without shifting its base, it gathers the food from a
circular area, moving on at intervals to commence a new series
of extensions. In this habit, peculiar to the limited family of
which it is the most common representative, I seem to trace
the result of feeding in a restricted area, where food is scarce
and where every particle must be utilized.

Thus, the characteristic arrangement of the cilia, while
probably detrimental to the existence of the species in pools
and ditches, is distinctly advantageous to it in certain moss-
habitats.

There are, however, many of the Notommatadas whose cilia
are also arranged upon a face more or less prone and flattened,
and which commonly feed while crawling about. In these
cases the cilia have usually sufficient power both to attract to

148 1). HRYCE ON THE ADINETAD^.

the mouth, when feeding, particles not lying directly in the
path, and, when swimming, to propel the animal at a fair
speed. Such animals should, in moss-habitats, be able to
creep about and compete with Adineta for its food supplies,
and, perhaps, outstrip it there, as they and other free-
swimming forms have done in the open waters, and it is true
that in mosses which habitually grow in wet positions, such as
Sphagnum, many of such species do occur. Where, however,
the moss grows in a position usually dry, and is dependent for
moisture upon showers or falling dews, they are rarely met
with, and it is obvious that they cannot endure the alternations
of moisture and of dryness experienced by such dry-growing
mosses.

Here, then, Adineta, in turn, has the advantage, for, with
many others of the Bdelloida, it can protect itself from the
effects of evaporation. When- the species was first described
by Mr. Davis in 1873, he stated, as the result of many trials,
that it possessed a surprising tenacity of life in this particular
direction, and it is on record that in this it excels even
Philodina roseola, another noted victim of artificial desiccation.
It is certain that the experiments by which Mr, Davis tested
the vitality and the endurance of this form were far more
severe than the conditions to which it would be subjected in
moss growing in the most exposed situations.

It may be urged that the same advantages would be enjoyed
by Adineta oculata, a form remarkably close to A. vaga both in
structure and in manner of creeping and feeding, yet having
two eyes absent in the latter. I have found it but once, and
then on weeds from running water from the river Lea, and I
have seen it recorded by no other observer than its discoverer,
Mr. Milne, who got it from a pool near Aberdeen, or some 500
miles distant.

There is thus some reason to believe that this eyed species is
rare, and I think we may infer that its scarcity in pools is (as
in the case of Adineta vaga, and so far as that scarcity may be
real) a result of its inability to swim. I made no experiments
with my colony, but the form may be supposed to have a
tenacity of life equal to that of vaga. Why has it not obtained
a like foothold in moss ? In his treatise descriptive of Callidina
symhintica (p. 49), Dr. Zelinka gives two reasons for his con*
elusion that that species leads a life of nocturnal activity and

D. BRYCE ON THE ADINETADj:. 149

diurnal rest: — the first is, that, wet weather excepted, the
mosses in which it lives are at their maximum of dampness
during the night as a result of dewfall, and the second, that
that species has no eyes. Mr. Percy Thompson has also
suggested, apropos of some other forms, that a species with
eyes, becoming resident in moss, would possibly tend to
become a blind form. These three principles, dovetailing into
each other as they do, may well account for the absence of
Adineta oculata from moss- washings. It is sufficiently near to
A. vaga to suggest that both forms were originally one and the
same, that with eyes being possibly the older type, and that
the eyes were lost in A. vaga, either by its having become a
feeder by night, that season being the most favourable in the
dry-growing mosses, or because, when living among the wet
mosses, it would be in the dark, even while able to be active in
hours of daylight.

Returning again to A. taga, I have for some little time
thought that there exist two well-marked varieties of the
species. I do not say that intermediate forms do not occur,
but the majority of individuals belong definitely to the one
variety or to the other, and both are frequently present in the
same moss. That which I call the var. major is usually
larger and stouter, with the head broader in. proportion, the
styles, which protrude just above and to right and left of the
anterior edge of the prone face, strong and bold, while the
posterior trunk segments are sharply divided from each other.
The var. minor is altogether slighter, the styles are incon-
spicuous, while the trunk segments decrease gradually and
without break of lateral outline. It occurs much more
frequently than the other. I do not know that these points of
divergence are so important as to mark the forms as distinct,
species, but I hope, by breeding them apart, to ascertain whether
they are actual races or merely stages of development.

What I term styles are apparently modifications of the
membranous flaps, conspicuous in many of the Callidinse at
the tips of the column. They have hitherto been described as
hooks, but I think erroneously.

I conjecture that these two forms were known to Mr. Milne,
who, writing in 1886, was seemingly unaware that a descrip-
tion of A. vaga had been published long before, for, while
stating that he had found two other species with coronas and

160 D. BRYCE ON THE ADINETAD^.

manners similar to those of his oculata, he refers one, it is
true with much misgiving, to the Callidina hidens of Gosse,
and states of the other simply that it is distinct, all three
forms having two teeth on each ramus. He considers that
Ehrenberg's figures of Callidina indicate species with a similar
formation of the ciliary organs, and to show that Continental
observers were not themselves clear upon the point, I find in
Dr. Zelinka's treatise (p. 56) a comparison of definitions by
other writers of the genus in question. Among them is one by
Eyferth, in " Simplest Forms of Life," published in 1878. I
translate one sentence only : " Column and ciliary organ
soldered to an acorn- shaped (viewed from above), weakly
ciliated, outstretched head."

Upon this Dr. Zelinka remarks that, " according to Eyferth,
the column is always outstretched and with, the ciliary organs
soldered to an acorn-shaped head," a representation which, he
proceeds, is only to be explained by the author having either
never watched a living Callidina for a time, or that he has
wrongly understood what he has seen. The criticism is an
unfortunate one. Eyferth's words describe Adineta vaga very
closely, and as, in those days, every Bdelloid, which had no
eyes, was called a Callidina, it is not surprising that he should
have assigned its peculiarities to the genus. But it is surpris-
ing to me that Dr. Zelinka himself should not have seen A.
vaga, after his long researches on moss-dwelling Callidinas, but,
beyond including Mr. Davis' article in his Bibliography of the
Botifera, he makes no reference to the species, although dis-
cussing the relative characters of several other and earlier
described forms. I can only infer that vagas geographical
distribution does not extend to Bohemia.

I have now to introduce to you a third species, which I
propose to name

Adineta clauda (n. sp.).

Sp. Ch. : Outline maggot-like, segments coarsely marked ;
trunk with lateral longitudinal skinfolds. Head as broad as
long, only partly protruding from neck segments. Foot short,
thick, apparently abruptly truncate, and ending in broad,
sucker-like disc. Second foot-joint a mere skinfold, furnished
posteriorly with a row of about ten small, fleshy, papilliform
lobes of varying size. Eyes absent.

D. BRYCE ON THE ADINETADiE. 151

The great divergence of this species from the Adinetas already
known ought, perhaps, to entitle it to be placed in a new
genus, but in the anticipation of further variations from the
type being found, T prefer to postpone any definition of suitable
generic characters. There is little to add to the specific
characters detailed. The sucker-like foot seems to link the
species to Discopus, the remarkable marine parasitic genus.
It appeared to consist of one stout upper joint, ending in a
circular disc, which was applied to the glass, a second joint
being represented by a mere skinfold, having the lateral and
dorsal (i.e., posterior) margins furnished with ten small pro-
cesses, in place of the usual spurs ; while from the centre of
the disc were pushed out momentarily, in the act of taking
hold, the usual small lower foot-joints. The animal seemed to
have no power of rapid movement, but slowly extended and
clumsily crawled about, without a trace of the gliding motion
so noticeable in the other species, and this halting awkward
gait has suggested the specific name assigned to it. The
mastax was rather small and appeared to have two teeth on
each ramus. The skin on the ventral side of the neck seemed
always to partially cover the face, and was prominent and
ridge-like, somewhat hard and rough on the edge. In feeding
there seemed a distinct scraping of the food surface, the central
line of the face being lifted and made concave, and the
roughened edges of the neck-skin approaching each other funnel-
wise, much more distinctly'- than I have seen it in ^. vaga.

Length, about ijg-th inch.

Habitat, moss.

For this species I am indebted to a fellow-member of this
Club, Mr. G. S. Marryatt, who very courteously offered to
procure for me some liver-mosses, and who sent me a quantity
of various descriptions from Garelochhead, IST.B., in the spring
of this year. One specimen only was found, and, unfortu-
nately, my opportunities for its examination were small, as I
failed to keep it more than a week, and it was very averse to
the needful illumination.

Description of Figures. Plate XI.
1. Adineta clauda, dorsal view.
la. Ventral aspect of head.
16. Ventral aspect of foot.

152

Note on the Determination of "Optical Tube Length."
By a. Ashe.

{Read October 21st, 1892.)

This is one of those practical matters the investigation of
which many microscopists postpone indefinitely, and generally
end by neglecting entirely, under the mistaken impression that
its solution is involved in much difficulty, requiring an advanced
knowledge of the laws of optics and a large amount of manipu-
lative dexterity in order to arrive at a satisfactory result, and
that even if a correct measurement can be made the informa-
tion so obtained is of no real value to the worker.

The fallacy, however, of this latter view is so obvious that it
needs no refutation to anyone who has taken the trouble to
estimate the magnifying power of his own instrument.

To those who are content to accept the figures given in an
optician's list as to the amplification of their various lenses the
following quotation from Mr. Crisp's well-known article may
carry some weight : —

" Microscopists have always recognized that the length of the
tube of a microscope is a factor in determining the amplifica-
tion of the image, that the amplification is generally greater
with a 10-inch tube than with one of six inches, and that we
obtain an increase of power by pulling out the draw-tube.
Here, however, all exact notions as to the functions of the
tube length have practically stopped, so much so that there has
not been any agreement even as to how the length of the tube
is to be measured, whether from the front or back lens of the
objective to the field-lens, the diaphragm, or the eye-lens of the
eye-piece."

Since these lines were written, now some eight years ago, it
has come to be very generally admitted that the optical tube
length must be measured from the posterior principal focal plane
of the objective to the anterior principal focal plane of the ocular.

A. ASHE ON THE DETERMINATION OF OPTICAL TUBE LENGTH. 153

But the question obviously arises, where are these focal
planes situated, how are their positions to be located, and the
distance between them estimated ?

The desire for information on these points will certainly not
be rewarded by any light the average microscopical text-book
may throw on the subject, for, whilst laying stress upon the
relationship existing between tube length and amplification,
they generally leave the reader very much to his own
resources as to the methods employed in solving the former
part of the problem.

A recent article* in the " Journal of the Royal Microscopical
Society " on this subject is very interesting, but, unfortunately,
the method suggested, whilst perfectly accurate and thoroughly
scientific, incontrovertible in its theory and capable of giving
most excellent results in the hands of an expert, is yet, from
its very nature, far too complicated in the details of its manipu-
lation and abstruse in its mathematical principles to meet the
requirements of the average worker, whose possession of
apparatus is seldom of such an extent as to warrant his under-
taking an optical research of no small magnitude, and who
frequently hesitates to trust his conclusions to figures obtained
by the exercise of a long-forgotten skill in the solution of
algebraic equations.

Under these circumstances I beg to call your attention to a
simple method of estimating the tube length which will not
involve the use of difiicult formulae or any apparatus beyond
an ordinary stage micrometer.

It is based upon the increase in power obtained by extending
the draw-tube through some measured distance, and is carried
out thus :—

A careful estimate is made of the power of the microscope
with the draw-tube pushed home as far as it will go, then
having determined this the eye-piece is withdrawn three or
four inches, the exact amount being noted and the increased
power of the instrument remeasured.

We are now in possession of all the data necessary to calcu-
late — not the actual optical tube length, but its arithmetical
equivalent — a distinction to be observed, though the difference
is immaterial to the purpose in view.

♦ ♦• R. M. S. Jouraal'" (1892), pp. 545, 546.

154 A. ASHE ON THK DRTEIIMTNATION OP OPTICAL TUBE LKNGTIT.

As it is a rule in optics that the relative sizes of images
formed by a lens at different points in its axis are in strict
proportion to the distance of those points from the focus of the
lens, we may arrange the following formula : —

^ - D

"Where A = Amplification of the instrument with the tube closed,
^j B = Distance the ocular has been withdrawn.
„ C = Increase in power produced by the effect of B.

D is, therefore, the equivalent of the distance separating the
focus of the objective from the anterior focal plane of the ocular.

To illustrate this simply, suppose an instrument magnifies
lOG times, and that on withdrawing the eye-piece three inches
the power is found to be increased to 130 times, the equivalent
of the tube length will be by the above rule, 10 inches.

That it can be nothing else can be shown by the old Euclidean
process of assuming it to be something else and ascertaining
how far this hypothesis agrees with observation, which, of
course, will end in a reductio ad absurdmn.

The chief drawback of this proposed method is that it does
not enable the worker to place his finger on any point on the
tube and say with certainty, " Here lies the posterior focus of
the objective and there the anterior focus of the ocular," but
it faithfully gives us a figure which is the equivalent of
the distance separating these two points, and this, after all,
is the only concern of practical import.

In conclusion, I may point out that there is frequently an
extraordinary discrepancy between the true optical and the
actual mechanical tube lengths ; thus in the case of an instru-
ment in my possession a certain combination of lenses gave an
optical tube length of 4J inches, whilst the substitution of
another objective in a much shorter mount increased the tube
length from 4J to 1\ inches, which, if not allowed for, would
introduce errors amounting to 60 per cent, in the calculated
powers.

Perhaps this may be considered an extreme case, but it
serves to emphasize the importance to the microscopist of
knowing something more about the optical length of his instru-
ment tube than can be ascertained by comparing its outside
dimensions with a foot-rule.

155

Notes on Rotifers, with Description of Four New Species,
AND OP THE Male of Stephanoceros Eichornii.

By Geo. Western, F.R.M.S.

Plate IX.

{Read October 2lst, 1892.)
Pleurotrocha grandis=Diglena jerox.

In April last year I described a Rotifer which I find in the
river Wandle, and which is unmentioned by any of the author-
ities, I then doubtfully assigned it to the genus Pleurotrocha,
chiefly on account of the absence of eyespots. Since the
publication of my note on the subject, which, with Mr. Chap-
man's figure of the Rotifer, will be found in the Journal of this
Club for July last, I have had opportunities of examining speci-
mens of Diglena rmistela, which it very closely resembles, and
have come to the conclusion that it would more properly be
classed along with that species. Mr. Gosse did not consider
that the absence of eyespots excluded that species from the
genus Diglena, and therefore I see no reason why mine should
not also be admitted. There is already, however, a Diglena
grandis, and to prevent confusion it is necessary to change the
specific name also. In future I propose to call this Rotifer
Diglena ferox.

Pterodina on Asellus vulgaris.

It may be remembered that when Mr. Parsons described a
new species of Pterodina which he had found living com-
mensally on Asellus, and which he named Pterodina cceca, 1
mentioned that in seeking for that Rotifer I had also found the
P. truncata of Gosse, and, as I then thought, more than one
other species. Having since pursued this subject with some
care, I have arrived at the conclusion that I have really met
with but three species, viz. : — Pterodina coica. Parsons; P.
truncata, Gosse, and P. elliptica of Ehrenberg. The great

156 G. WESTERN ON ROTIFERS.

variety of form whicli I tlien thought amounted to specific
difference is, I believe, due to the condition of the reproductive
system or to the repletion or otherwise of the digestive organs.
The Pterodina described by Dr. Barnett Burn in " Science
Gossip," 1889, p. 104, differs in some respects from that which I
consider the P. trmicata of Gosse (vide PI. XXV., Fig 4, Society's
Journal, January, 1892), and may possibly be another species,
but I have not as yet been able to find it. 1 have been much
assisted in this investigation by Messrs. Bryce and Percy
Thompson, both of whom appear to have been acquainted with
these forms of Pterodinge before my attention was directed to
them by Mr. Parsons.

Philodina commensalis (sp. nov. mihi).

Sp. Char. : Body smooth ; corona large with slightly bulging
neck ; eyes roud-ovate, oblique ; teeth two ; foot thick, abrupt ;
spurs large ; animal hyaline, colourless ; living on Asellus
vulgaris. Length -^^ in.

In the January number of this Society's Journal, on PI. XXV,
Fig 2, Mr. Chapman has given a sketch of a Philodina, which I
also found living commensally on some Asellus. As there
appears to be no published description of this Rotifer it is
necessary to give it a name, and as I have never found it except
attached to Asellus, I propose to call it P. commensalis. At
first sight it much resembles a Rotifer macrurus, but it has
nevertheless more of the square compact form of a Philodina.
It is hyaline and colourless except for the contents of the
alimentary canal. The body is marked with the usual longi-
tudinal flutings, and merges abruptly into the longish thick
telescopic foot, which is armed on the penultimate joint with
conspicuous spurs, and terminates in the usual toes. The spurs
are peculiar in shape, having a distinct heel and being
separated by a gap, which is equal to about half the width
of the base of the spur. They are broadest at the base, then
contract slightly and again widen before tapering to the point.
The corona is large, measuring quite the width of the body
when the animal is swimming. The neck is thickened and
bulging. The frontal column is of the ordinary form. The
antenna tapers towards the extremity and is carried rather
backwards. Eyes are pale roud-ovate and set at an angle like

n. WKSTKR^ 0\ KOTfFKIJS. 157

those of p. citrina. There are two teeth in each ramiis of the
trophi. The viscera present no peculiarity requiring notice.
The "reproduction is viviparous. They vary much in size, but
average ^^'oin. in length. Habitat : Commensal on Asellus
vulgaris from Putney, Wandsworth, and Epping Forest.

Stephanoceros Eichornii: The Male.

Although I imagine every member of this Club is acquainted
with the handsome rotifer Stephanoceros, and although it has
been known since 1761, marvellous to relate, there is no record
that anyone has seen the male. Thanks to Mr. Hood, of
Dundee, I have recently had an opportunity of doing so, and,
though of course all credit for the discover}^ is due to Mr. Hood,
who, it seems, found and hatched the male eggs last year and
sent specimens with descriptions and drawings of the male to
the Glasgow Microscopical Society, so far as I can learn nothing
has been published, and I deem the matter of sufficient interest
to bring before you. It was in April that Mr. Hood sent me
some Stephanoceros, some of which carried male eggs. He told
me that he had been unable to find these luale eggs after May
last year, but being on the look-out for them found them again
in April this year. I have met with but few Stephanoceros
this year, and have looked in vain for the male eggs, the season
being probably past ; with those sent me by Mr. Hood, however,
I was very fortunate, for I was able to keep them until the
males appeared. These male eggs were more numerous and
only about half the size of the ordinary female (partheno-
genetic) ova, each female carrying upwards of a dozen of them
within the body. Some I measured were about 3-5^in. in
diameter. They were laid in batches of three or four, some
two or three hours before the young males emerged from them ;
I could see decided movement of some of the embrj'os inside
the body of the female before the eggs were laid, but in no one
instance did I observe a male born alive. On the contrary I
almost invariably found the empty shell from which the young
had escaped. After birth the young males, measuring about
^-^-^in., were within the tube, and from it I distinctly saw two or
three of them bore their way out through the side, leaving in
one case a hole with ragged edges. This process took them six
or eight hours. The appearance of the male is much like that

JouRN. Q. M. C, Series II., No. 32 11

158 <i. WESTEKN ON HOTIFEKS.

of other of the floscularian males, and I have roughly sketched
it to assist others in future identification. There is a sort of
head with two red eyespots. This is suri'ounded by a ciliarj^
wreath, of which the cilia are very long and active. Below this
the body gradually tapers to the foot. There are two antennaa,
to which, as to the eyespots, nerves could be traced from a
largish square-shaped ganglion in the neck. The sperm sac
occupies the lower half of the body cavity. There is also a
small contractile vesicle, and the lateral canals, with at least
three vibratile tags on each side, are easy to make out.

The development of the female has been described b}^ Mi-.
Gosse and others, and I have been able to contirm his observa-
tions. The eggs I saw developed were, however, invariably laid
as eggs before the birth of the young, and I have, as yet, seen
no instance of viviparous birth. The eggs were also all laid
before the death of the parents, which, however, invariably died
before they were all hatched. Viviparous reproduction has
been seen by Rosseter, English, Hood, and others.

Notholca Hoodii (sjp. nov. inihi).

Sp. Char. : Lorica ovato-rhomboid, broadly truncate and with
six spines before, narrowly behind ; ridges and furrows strongly
marked and reaching to posterior margin ; two lateral spines on
oater surface of dorsal plate of lorica.

This somewhat resembles both Notholca jugosa and Notholca
spinifera. It differs from the former, however, inasmuch as
the ridges and furrows on its dorsal lorica reach quite to the
posterior margin, and from the latter in the position of the
lateral spines, which, instead of protruding from between the
two plates, are on the outer edge of the external surface of the
dorsal plate, at about the junction of its middle and lower third.
I have only seen them lying flat upon the dorsal plate, and was
unable to ascertain whether they are moveable like those
of N. sjnnifero, as my specimens were few and in a dying
condition.

Atmrrea hiremis of Ehrenberg, another species with spines
similarly situated, has only four occipital spines instead of six,
which that now described possesses. I am indebted to Mr.
Hood, of Dundee, for this Rotifer, who found it at Westport,
Ireland, in sea water.

(i. \VE.->TER\ OX IJUTIFKK'S. ir>9

Battubis hicornis (sp. nov. mihi).

Sp. Char. : Body fusiform, with two equal occipital spines ;
toes two stylate, equal ; substyles two ; brain clear.

This little fellow I found at Roehampton, but although ap-
parently undescribed, I learn that it is common also in Scotland
and Ireland. Its distingaishing feature is the presence of the
two equal spines on the occipital edge of the lorica. The whole
lorica has also a twisted appearance, and the method of swim-
ming is peculiar. The trophi are of the usual asymmetrical
virgate pattern, and its internal economy being as ordinary in
members of the genus, needs no comment.

Length about yjoin.

Habitat — Pond near Roehampton, Scotland, Ireland ;
common.

Callidina sordida {sp. nov. mild).

Sp. Char. : Body fusiform, depressed, with alternate enlarge-
ments and contractions ; opaque ; greyish brown ; much
corrugated and covered with adhering foreign matter ; teeth
two ; foot short and thick ; spurs long and flexible at points ;
two tubercle-like processes on dorsal surface of neck on level of
antenna.

This is a large Callidina resembling both Uotifer tardus and
Philodina macrostyla in general appearance, but intermediate in
size and paler in colour than either of these Rotifers. It is
very sluggish and torpid in habit, being mostly found in a
retracted and seemingly dormant condition in the muddy sedi-
ment of the washings of the moss amongst which it lives. It is
always thickly encrusted with stones and other foreign matter
entangled in the viscous secretion which covers it. The integu-
ment of the body is very tough and coriaceous in character, and
ma}^ often be found intact, like an empty shell, after the death
of the animal and the disappearance of the softer parts. The
longitudinal flutings are very marked. The body is less
changeable in form than that of B. tardus, and when the
animal is moving it retains its somewhat fusiform but de-
pressed shape, with alternate prominent swellings and con-
tractions. The head, neck, and foot are perfectly transparent
and colourless, and it is when the head is slowly protruded
that the most distinctive feature of the species becomes

160 C. WESTERN ON ROTIFEIIS.

apparent, viz., tubercles or horn-like processes at the base of
the neck on either side of the dorsal antenna. The corona is
powerful, and when extended is about two-thirds the width of
the widest part of the body. The anterior column is stout and
long. The buccal orifice is wide, and the lower lip large and
prominent. The dorsal antenna is sturdy and of the usual
form. The trophi are large, with two teeth on each ramus.
The foot, which is onlj^ protruded when the Rotifer is crawling,
is stout and gradual. It is armed with two fair-sized pointed
spurs, which are flexible at the ends, but less evidently jointed
than those of E. tardus. The toes are three, and also want the
telescopic joints of those of that Rotifer. Its average length
is 4^^in.

I found it in moss which came from Epping Forest.

161

The Entomostraca of Wanstead Park.*

By D. J. SCOURFIELD.
{Read 2iovemher l^th, 1892.)

So far as can be ascertained from the literature dealing with
the British Entomostraca, comparatively few attempts have
been made in this country to obtain good local lists of these
very interesting micro-Crustacea, or to systematically watch
their appearance in limited areas. The following notes, there-
fore, of observations upon the Entomostraca of "Wanstead
Park, extending over the last three years, will probably
possess some interest for students of the inhabitants of our
lakes, ponds, and ditches.

An undertaking of this sort, if properly and exhaustively
carried out, would undoubtedly yield valuable results. So
little is certainly known of the distribution of microscopic
organisms, of the causes of their apparently capricious appear-
ance and disappearance in particular localities, or of the
developmental cycles which many of them pass through, that
reliable data bearing upon these subjects would necessarily be
of considerable importance. Such data can, for the most part,
only be obtained by the careful and long-continued examination
of the forms found in small areas, or even in single ponds, in
various parts of the country. But it is unreasonable for any
one worker to expect to be able to do this completely by himself.
In fact, from my experience with the Wanstead Park Ento-
mostraca, I am inclined to think that it is quite impossible for
a single individual, even when restricted to a small group of
animals, to do full justice to the most limited district. At any
rate, I am painfully conscious of my own shortcomings in the
attempt. Yet. while believing that much of this work must of

* A short account of this Park, with a good map, will be fouud in £. N.
Buxton's excellent little book on " Epping Forest," published by Stanford.

162 l». .1. 800URFIELI) ON KMOMOSTKACA.

necessity be done by co-operation, I hope this record will show
that, at least, a number of suggestive facts may be accumulated
by isolated workers. But it must be remembered by those who
may think of commencing or assisting in similar observations
apon this or other groups of pond-life, that, unless made with
care, such records are worse than useless, and this, of course,
implies that, if taken up at all, a considerable amount of
labour, almost bordering upon drudgery, must be expended
upon them.

In the present case little has been attempted beyond the
mere noting of the species found at each visit. The record,
therefore, although quite reliable, I believe, as far as it goes,
does not throw much light on many points about which
information is sadly needed. In spite of this incompleteness,
however, there are a few results that appear to stand out
pretty clearly, and which, to some extent, justify the work.
The most obvious of these, if not the most interesting, is that a
rigidly local list has been formed. It is probably by no
means exhaustive, although the few additions made during the
last two years seem to show that it embraces by far the larger
number of the forms actually living in the Park. In common
with all other local lists, the present should have some value in
connection with the question of distribution, but it is impossible
to say anything on this point at present, owing to the very small
number of such lists hitherto published. Its relation to our total
known fresh-water Entomostracan fauna is, fortunately, more
definite, and a comparison with the latter may prove instructive
in several ways. Altogether, it appears that about 150 species
have been so fai* recognized as British, and they belong to the
various orders as follows : — Phyllopoda, 2 ; Cladocera, 63 ;
Branchiura, I ; Ostracoda, 51 ; Copepoda, 33. The number of
species here recorded for Wanstead Park is 60, namely:
Cladocera, 33 ; Branchiura, 1 ; Ostracoda, 12 ; and Copepoda,
14. The water-fleas of this little district are, consequently'-,
equal in variety to two-fifths of the fresh-water forms known
to inhabit the whole of the British Isles, while of the three
main orders, the Cladocera show a proportion of a little over a
half, the Copepoda somewhat under a half, and the Ostracoda
a little under a quarter of the full records in each order
respectively. The I'elative smallness of the Ostracod list may

i'. .1. scdl KKIKLI) (I.N i;\I'O.M(»s||;A(A. If))]

possibly- be due to the fact that sufficient attention was not
given to the collection of bottom-sediment, in which many
species of this order habitually occur, but it must also be noted
that some of the forms included in the complete British list,
although occasionally found in fresh-w^ater, are more typically
brackish-water animals, and ought scarcely to be put in
comparison with those from Wanstead Park.

A second result, arising incidentally from the effort to make
as complete a list as possible, is that one new species has been
found, and a few others added to the British fauna. The new
species belongs to the genus Cancloua, and is considered by
Prof. G. S. Brady to be quite distinct from all those previously
known. He has provisionally given it the name of Candona
ahhreviata, and has undertaken to describe it. This will pro-
bably' be done in an appendix to the Monograph of the Ostra-
coda of the North Atlantic and North- Western Europe, a
second portion of which is in preparation by Prof. Brady and
the Rev. A. M. Norman. The other species alluded to as
having been added to our Entomostracan fauna are Cerio-
daphnia megops, G. quadrangula, Baphnia galeata, and Alona
intermedia. They have already- been described before this
Society {ante^ pp. 63-69, Plates IV. and V.). and it need only
be added that although subsequently found in. other districts,
Wanstead Park was the first place from which these forms
were taken.

An examination of the first two Tables appended wiW show
that another result has been to obtain some useful evidence as
to the periodicity of many species. This periodicity, although
well knowai among the Cladocera, is not, so far as I am aware,
usually recognized as occurring among the Ostracoda and
Copepoda. The data furnished by this record, therefore, may
have some value in suggesting unsuspected powers of repro-
duction in the latter orders, while even in the case of the
Cladocera, some additional light may possibly be thrown upon
the limits of the active and resting periods in different species.
I do not pretend to say that the periods of activity' found to
hold good in these cases at Wanstead Park would be exactly
matched in other districts ; indeed, I have many facts to the
contrary, and on purely a priori grounds it is scarcely likely
that this precif;e agreement should exist. Nevertheless, the

1H4 D. J. HCOURFIKI.I) OX hJNTUM* (JriTKAt'A.

fact that in this particular area some of the species iiave
appeared and disappeared each year with very considerable
regularity is a point that must have at least some significance
in relation to the life-histories of these forms and the conditions
necessary for their existence. Leaving out of consideration the
rarer forms, whose capture must have been more or less acci-
dental, it appears that about sixteen species of Cladocera, four
of Ostracoda, and three or four of Copepoda show a limited
seasonal distribution. These, with their periods of activity,
are shown in table on p. 165.

It is true that b}' looking only to the earliest and latest
records obtained during the three years, as done in the following
list, the active period seems to extend in some cases to as much
as nine or ten months, but if taken year by year it will generally
be found somewhat shorter ; and I have also observed that in
some of these instances of exceptionally early or late records,
onl}' a single specimen was seen or only young forms taken.
On the other hand it will be seen that in two cases the active
period only lasts for three months. A few further comments
on this subject w^ill be given later among the detailed notes of
species forming the second part of this paper.

The next result, and the last that seems at all definite, is in
close dependence upon the periods of activity and rest alluded
to in the preceding paragraph. It is that a w^ell-defined cycle
of seasonal distribution of species has been made out in the
case of the Cladocera. The evidence of each year on this point
is practically the same, as show^n by the following statement of
the number of species of Cladocera taken at each visit : —

Jan. Feb. Mar. Apl. May Jane Jnly Aug. Sept.

1890 ... — 6 6 11 16 — 18 13 22

1891 ... 1 7 6 10 9 — — 17 18

1892 ... 6 — 5 11 11 16 17 — 21

Averagef 4 7 6 11 12 16 18 15 20 18 17 10

It will be seen that, with the exception of two or three
slight breaks, there is a gradual increase during each year
from January to September, then a slight decrease to about

* This and her records for December, 1892, have, of course, been in-
serted since thc^ *-ding of the paper.

+ Fractions ^{^,e-half and two-thirds counted as one in this and other
uverayes given t . ucdlIv .

Oct.

Nov.

Dec

19

16

—

17

17

10

18

19

10^

D. J. SCOUKFIKLD ON ElSTu.MdfcTKACA.

166

Species.

i

t-5
...

o

a i

13

1-3

i

1

1

X

s
2

s

1

§

>
o

X

X)

B

1

Sida crifstallina

Daphnella hrachyura .

...

...

...

X

X

X

...

Ceriodaphnia megops .

...

...

X

X

X

X

X

X

„ rotunda*

...

...

X

X

X

X

X

X

X

,, reticulata

...

X

X

X

X

X

X

X

,, quadrangula .

...

X

X

X

X

X

X

X

X

Scapholeheris mucronata

X

X

X

X

X

X

X

...

Daphnia galeata

..

...

X

X

X

X

X

X

„ cucullata

...

...

X

X

X

X

X

X

Bosmina longirostris .

X

X

X

X

X

X

X

X

X

Eurycercus lamellatus

X

X

X

X

X

X

X

X

X

Camptocercus macrurus

X

X

X

X

X

...

Alona costata

...

...

X

X

X

X

X

Pleuroxus irigonellus .

X

X

X

X

X

X

"

X

X

Peracantha truncata .

X

X

X

X

X

X

X

X

X

X

Chydorus glohosus

X

X

X

X

X

X

X

X

X

X

Cypria ophthalmiea .

X

X

X

X

X

^

X

...

...

X

X

Notodromas monacha .

...

...

...

X

X

X

X

X

C'andona Candida

X

X

X

X

...

X

X

„ fabceformis .

X

X

X

X

...

...

X

X

X

X

Diaptomus castor f

X

X

X

X

X

X

...

...

...

X

X

Cyclops Scourjieldi .

X

^

X

X

X

X

X

X

X

,, ricinus .

X

X

X

X

X

X

...

X

X

X

^

„ hicuspidatus .

X

X

X

X

X

X

y \

X

1

X

X

X

J in(

* The very exceptional nature of the singrle Feb " record of this

species prevents it from being taken into consideratic-'^aere.
f This case rests npon the evidence of one vear only.

lt>6 h. .1. SruL'RKiKliD ON EiNTOMuS I'RACA.

the middle of JS'ovember, and from thence a very rapid fall to
January again. It thus takes eight months to rise from
minimum to maximum, but only half that time to fall from
maximum to minimum. The averages for the whole period
bring this out still more clearly, and the breaks already referred
to are reduced to one in March and one in August (see also upper
curve of diagram). These temporary retrogressions deserve a
few moments' attention. They may, of course, be due simply
to the accidents of collection, but it is also possible that they
do represent a real falling oft", if not actually in the number of
species, at least in the abundance of some, thus causing them
to be more easily missed. I am certainly inclined to take the
latter view, because in the first place the same breaks have
been found to occur in a more marked manner in the records
from a single pond (see middle curve of diagram), and secondly
because some reasons for the probability of such breaks can
be put forward. For instance, the decrease in March may
really arise from the fact that during February resting-eggs that
happen to be in particularly favourable situations hatch out
prematurely, only to be quickly killed by the later frosts or
lack of food. There is a good example of this in the case of
Geriodaphnia rohmda, one record of which is for the 28th Feb.,
1891, though it was not seen again for at least three months.
I noted at the time that only a single specimen was found, and
also that it was a young one. Again the decrease in August
may be due to the great heat of that month, and the accompany-
ing lessening of the volume of water in most of the ponds.
Returning, however, to the consideration of the main features
of the yearly cycle, it must be noticed as a singular circum-
stance that the period of maximum development is coincident
with, or at most only slightly antecedent to, the principal
sexual period of the year, and further that the comparatively
high figures reached in June and July seem to be in close con-
nection with a subsidiary season of sexual activity. The true
import of these facts must, so far as I can see, remain more or
less a matter of speculation at present, but they suggest a
possible line of special investigation for the future.

Having nov rjisposed of the chief results obtained from the
study of the Wt?,nstead Park Entomostraca, there remain for
examination onlyii few miscellaneous points of a more or less

I). .1. SCOUHFIELD UX ENTOMOSTRACA. 1 67

indefinite character. One of the most noticeable of these is
the curious non-appearance of some species of Cladocera in
1891, e.g., Sida crystalUna, Alona costafa, and Alonella nana.
This is the more strange because each of these had been pre-
sent in 1889 as well as in 1890, and they are all forms that
occur pretty plentifully when they do put in an appearance.
The first named, too, is one of the largest of the Cladocera, and
it seems quite impossible to believe that it, at any rate, could
have been overlooked. The most plausible hypothesis to ac-
count for their absence seems to be that the unusually severe
winter of 1890-91 proved fatal to them in some way or other.
In the case of Sida crystalUna this view receives some apparent
support from the fact that the resting-eggs of this species, upon
which it entirely relies for continuance from year to year, are
dropped to the bottom of the pond, covered only by their own
proper membrane, and not enclosed in a protecting " ephip-
piiim " as among the Daphnidae. It seems likely enough,
therefore, that they are the more susceptible to extremes of
temperature. The particular spots, too, where this species
occurs in Wanstead Park are comparatively shallow, and even
the bottom mud may have been frozen solid by the prolonged
frost. In this case the pressure exerted upon all resting-eggs
would be enormous, and they would, no doubt, suffer \Qvy
greatly if not protected by such extrinsic envelopes as ephippia,
which would at least serve to equalize this pressure, and
probably to counteract it altogether if containing air-spaces.
But how this explanation can be reconciled with the fact of
non-appearance one year and reappearance at the same spot in
the next is more than I can undertake to say. One thing at
least the hard winter of 1890-91 was responsible for, if not for
the non-appearance of the speciei-j above-mentioned, namely,
the almost entire absence of Cladocera on the 31st January,
1891, when only a single individual of Simocephalus vetulus
could be found.

The periodical occurrence of Cladoceran males and " ephip-
pial " females is another point of considerable interest, and one
that must certainly be carefully attended to in future records.
Unluckily, in this case, no attempt was made until August,
1891, to separately note these sexually mature individuals, and
even since tliat date the records must be very incomplete in

168 J). J. SCOUHFIELD ON ENTOMO.STRACA.

consequence of the great rarity of these forms in many species.
Altogether I have seen sixteen males and eighteen ephippial
females. They are given at length, and their seasonal distribu-
tion is shown in the third table appended to this paper (see
also lower curve of diagram). I do not think any of them are
new, with the possible exception of Alona costata, but there is
no reason why many successes should not reward diligent search
in this direction, as the males and ephippial females of a great
many species still remain to be discovered. And here I may
remark that much of the uncertainty as to the value of some
genera in this order seems to me to arise from the fact that
the original descriptions were necessarily based entirely upon
the parthenogenetic females. In any future revision of the
classification of these animals, the males and sexually mature
females will certainly have to be taken largely into account.

The results obtained in reference to the seasonal distribution
of the Ostracoda and Copepoda are somewhat vague, and not
very suggestive, but a short space may be conveniently devoted
to them among these more or less indefinite items that we are
now considering. It seems that the animals included in these
orders, as might, perhaps, have been anticipated, are pretty
evenly distributed through the whole year. If they do possess
a culminating period it is very probably not the same as that
of the Cladocera. It would rather seem as if the maximum
development of species was reached in the early part of the
year — by the Ostracoda in February and March, and by the
Copepoda in April. This is shown by the following statement
of the average number of species belonging to the two orders
found during the three years : —

Jan. Feb. Mch, Apl. May Juue July Aug. Sep. Oct. Nov, Dec.
Ostracoda .. 6876 4 4535544
Copepoda ... 9 9 9 11 8 10 7 7 8 7 8 9

It is quite clear, however, that a large amount of very care-
ful research is still needed to get trustworthy conclusions upon
this subject.

The last of these miscellaneous points that seems to call for
notice is in connection with the distribution of species within
the Park itself. By keeping separate records for the various
ponds, I hoped at one time to get some evidence of well-marked
sub-areas, characterized by special forms, and also, perhaps,

I). J. SCOUUFIEliD ON RNTOMOSTRACA. 169

evidence of gradual changes in the Entomostracan fauna. But
the results have been very unsatisfactory, notwithstanding the
fact that a few species have been found to be restricted to single
ponds. I think the most that can profitably be given here is a
comparison of the total number of species found in each of the
principal pieces of water. This is shown as follows : —

Clad.

Branch.

Ost.

Cop.

Total

Shoulder of Mutton Pond* 23

—

7

10

40

Heronry Pond ... ... 21

—

8

9

38

Perch Pond 28

1

10

10

49

The Lake 18

1

9

10

38

It wdll be seen, therefore, that the " Perch Pond" — probably
the deepest of all — is decidedly the best.

In the following detailed list of the Entomostraca of
Wanstead Park, some indication has been given of the places
where figures and descriptions of the species can be found
among British publications. Advantage has also been taken of
the opportunity to insert a few odd notes that could not
conveniently be given elsewhere.

Cladocera.

Sida crystallma, 0. F. Miiller (Baird, Nat. Hist. Brit. Ent.,t
p. 107, Tab. xii., Figs. 3-4, and Tab. xiii.). This species is con-
fined, so far as I can discover, to the " Shoulder of Mutton
Pond " and the little pond receiving its surplus water.

Daphnella brachyura, Lievin (Baphnella Wingii^ Baird, Nat.
Hist. Brit. Ent., p. 109, Tab. xiv.). This clear water loving
species finds its most congenial abode in the " Perch Pond,"
although it is sometimes met with in other ponds. I first
found it in " The Lake " in 1889, but it has not been seen there
since the choking-up of that piece of water by Anacliaris
in 1890.

Geriodaphnia megops, G. O. Sars (? Dap'hiia reticulata in part,

* These ponds may be identified from the map in Buxton's " Epping
Forest," already mentioned.

t "The Natural History of the British Entomostraca," by W. Baird,
Ray Society, 1850.

170 D. .1. SCOURFIELL) ON ENlOMOS'l'llACA.

Baird, Nat. Hist. Brit. Ent., Tab. vii, Fig. 5 ; Scourfield,
J.Q.M.C, Ser. ii, Vol. v., p. 63, PI. IV., Figs. 1-3).

Ceriodaphnia rotunda, Straus {Daphnia rotunda, Baird, Nat.
Hist. Brit. Ent., p. 98, Tab. ix.. Fig. 6, and Tab. x., Fig. 4).

Ceriodaphnia reticulata, Jurine (Daphnia reticulata, Baird,
Nat. Hist. Brit. Ent., p. 97, Tab. xii.. Figs. 1-2). Two modifi-
cations of this species occur at Wanstead Park. The most
evident distinction between them is to be found in the shape of
the fornices covering the bases of the large antennae. In one
case these are quite round, but in the other they are produced
into strong cusps. Males of both forms have been observed.
This species is the least common of the genus.

Ceriodaphnia quadrangula, O. F. Miiller (Scourfield, J.Q.M.C,
Ser. ii., Vol. v., p. 65, PI. IV., Figs. 4-7).

Scapholeheris mucronata, 0. F. Miiller {Daphnia rtiucronata,
Baird, Nat. Hist. Brit. Ent., p. 99, Tab. x.. Figs. 2-3). The
two well-known varieties of this species both occur at Wanstead
Park, but the "acute rostrata" or "cornuta" form is much
more common, and has a longer period of activity than the
" obtuse rostrata " form. From its rarity and late appearance,
I suspect that the latter is simply an advanced stage of the
former, i.e., a single individual, if living long enough, would
pass successively through the " acute " and "obtuse rostrata"
forms. The male of this species, recorded 3rd October, 1891,
was without the cephalic cornu, although all the females taken
at the same time, both with and without ephippia, were of the
" acute rostrata " type.

Simocephalus vetulus, 0. F. Miiller (Daphnia vetula, Baird,
Nat. Hist. Brit. Ent., p. 95, Tab. x., Fig. 1). This is the
commonest and hardiest of the Cladocera of Wanstead Park.
It has been taken repeatedly in all the ponds, and figures
through the whole of the record without a single break.
Directly after the frost of 1890-91, it was the only representa-
tive of its order that could be found. On one or two occasions
[ have seen specimens that would, probably, be better referred
to S. exspinosus, De Geer, if that can be considered a sufiiciently
well-marked form to merit a distinct name.

Daphnia pulex, De Geer (Baird, Nat. Hist. Brit. Ent., p. 89,
Tab. vi., Figs. 1-3, etc.). It is impossible to say for certain
whether the Wanstead Park forms referred to D. pulex are

D. .). SCOUJJFIEI.I) ON KNTOMOSTUACA. 171

really similar to those of the above reference or not. However
this may be, all the individuals so far found have been of one
type, a striking peculiarity of which is that the males possess
u7ie long spu.r, projecting from the dorsal side of the abdomen,
far beyond the edges of the valves. This is not a very common
species at Wanstead Park, but may generally be found in a
few special spots. It has never been seen in the '' Perch
Pond."

Daphnia longispina, 0. F. Miiller (D. pulex var. lo7ig{spina,
Baird, Nat. Hist. Brit. Ent., Tab. vii., Figs. 3-4). This is
the most abundant species of the genus at Wanstead Park.
It seems to occur all the year round with only a doubtful
break in early spring. The majority of the forms here in-
cluded agree very well with D. caudata, G. 0. Sars, now con-
sidered by that author to be simply a variety of D. longispina.
The remainder may possibly belong to a variety of D. lacustri.%
G. 0. Sars.

Daphnia hyalina, Leydig (Scourfield, J.Q.M.C, Ser. ii., Vol.
v., p. 66, PI. v., Fig. 1). Only seen on one occasion, viz., 23rd
April, 1892. It was from the " Perch Pond," of course.

Daphnia galeata, G. 0. Sars (Scourfield, J.Q.M.C, Ser. ii.,
Vol. v., p. 67, PL v., Figs. 2-3.)

Daphnia cucuUata, G. 0. Sars. No figure of this species is
to be found in any British publication that I have seen, but it
has been recorded from the Lake District by Mr. Conrad Beck.*
It is very closely allied to D. galeata, but the eye-spot is absent.
They are both found only in the " Perch Pond."

Bosmina longirostris, 0. F. Miiller (Baird, Nat. Hist. Brit.
Ent., p. 105, Tab. xv.. Fig. 3 ; Norman and Brady, Mon. Brit.
Ent.,t p. 6, PL XXII., Fig. 4). All the Wanstead Park
Bosminas seem to belong to this species. Although exhibiting
a considerable amount of variation, none of them ever approach
the B. longispina figured by Norman and Brad}^

Macrothrix laticornis, Jarine (Baird, Nat. Hist. Brit. Ent.,

* See the list of species appended to his paper " On some new Cladocera
of the English Lakes," in the " J.R.M.S.," Ser. ii., Vol. iii., 1883, p. 784.
Given under the synonym of Hyalodaphtiia berolinensis.

t " A Monograph of the British Entomostraca belonging to the families
Bosminidse, Macrothricidae, and Lynceidse," by the Eev. A. M. Norman and
G. S. Brady, " Nat. Hist. Trans, of Northumberland and Durham," Vol. i.,
1865-7, p. 354. Also published separately. The references to pages are
taken from the separate publication.

172 1). J. SCOITRFIELD ON ENTOMOSTRACA.

p. 103, PI. XV., Fig. 2; Norman and Brady, Mon. Brit. Ent.,
p. 9, PI. XXIII., Figs. 4-5.)

Ilyocryptus sordiduf;, Lievin {Acantholeheris sordidus, Norman,
Annals and Mag. Nat. Hist., Ser. 3, Vol. xi., 1863, PL XI.,
Figs. 6-9, and Trans. Tyneside Nat. Field Club, Vol. vi., p. 55,
PI. VI., Figs. 6-9 ; Norman and Brady, Mon. Brit. Ent.,
p. 17).

Eurycercus lamellatus, 0. F. Miiller (Baird, Nat. Hist. Brit.
Ent., p. 124, Tab. xv.. Fig. 1 ; Norman and Brady, Mon. Brit.
Ent., p. 50, PI. XX., Fig. 8).

Acroperus harpce, Baird (Baird, Nat. Hist. Brit. Ent., p. 129,
Tab. xvi., Fig. 5; Lynceus harpce, Norman and Brady, Mon. Brit.
Ent., p. 20, PI. XXI., Fig. 1).

Gamptocercus macrurus, 0. F. Miiller (Baird, Nat. Hist, Brit.
Ent., p. 128, Tab. xvi.. Fig. 9 ; Lynceus macrurus, Norman and
Brady, Mon. Brit. Ent., p. 22, PI. XX., Fig. 6, and XXI., Fig. 2).
This species has occurred regularly in the " Perch Pond " for
the last four years. It has not been taken elsewhere within
the Park.

Leydigia acanthocercoides, Fischer (Lynceus acanthocercoides,
Norman and Brady, Mon. Brit. Ent., p. 34, PI. XIX., Fig. 5, and
XX., Fig. 7). The solitary record of this species was from the
" Shoulder of Mutton Pond."

Graptoleheris testudinaria, Fischer ( Lynceus testudinarius, Nor-
man and Brady, Mon. Brit. Ent., p. 30, PI. XVIII., Fig. 7, and
XXI., Fig. 4).

Alona guttata^ G. 0. Sars (Lynceus guttatus, Norman and
Brady, Mon. Brit. Ent., p. 29, PI. XVIII., Fig. 6, and XXI., Fig.
10).

Alona tenuicaudis, G. 0. Sars (Lynceus tenuicaudis, Norman
and Brady, Mon. Brit. Ent., p. 25, PI. XIX., Fig. 3, and XX.,
Fig. 3). ■

Alona qtiadrangularis, 0. F. Miiller (Baird, Nat. Hist. Brit.
Ent., p. 131, Tab. xvi.. Fig. 4; Lynceus quadrangularis, Norman
and Brady, Mon. Brit. Ent., p. 26, PL XXI., Fig. 5).

Alona costata, G. 0. Sars (Lyyiceus costatus, Norman and Brady,
Mon. Brit. Ent., p. 28, PL XVIII., Fig. 2, and XXI., Fig. 7).

Alona intermedia, G. 0. Sars (Scourfield, J. Q. M. C, Ser. ii.,
Vol. v., p. 67, PL v., Figs. 4 and 6).

Alonella nana, Baird (Acroperus nanus, Baird, Nat. Hist. Brit.

I>. ,1, sroLKFIKLl' n.V KX I'oJKJSTK'A* 'A. \7'S

Ent., p. 130, Tab. xvi., Fig. 6 ; Lynceus nanus, Norman and
Brady, Mon. Brit. Ent., p. 45, PI. XVIII., Fig. 8, and XXI.,
Fig. 8).

AJjnella rostrata, Koch {Lynceus rostratus, Norman and Brady,
Mon. Brit. Ent., p. 43, PI. XIX., Fig. 1, and XXI., Fig. 6).

Pleuroxus trigonellus, O. F. Miiller (Baird, Nat. Hist. Brit.
Ent., p. 134, Tab. xvii.. Fig. 3 ; Lynceus trigonellus, Norman
and Brady, Mon. Brit. Ent., p. 40, PL XXI., Fig. 11).

Pleuroxus uncmatus, Baird (Baird, Nat. Hist. Brit. Ent., p.
135, Tab. xvii., Fig. 4 ; Lynceus uncmatus, Norman and Brady,
Mon. Brit. Ent., p. 42, PL XVIII., Fig. 9, and XXI., Fig. 13).
This is a rare species at Wanstead Park, but I found it more
plentifully in the autumn of 1889 than in 1891.

Peracantlia truncata, 0. F. Miiller (Baird, Nat. Hist. Brit.
Ent., p. 137, Tab. xvi.. Fig. 1 ; Lyncezis truncatus, Norman and
Brady, Mon. Brit. Ent., p. 36, PL XXI., Fig. 9).

Chydorus sphericus, 0. F. Miiller (Baird, Nat. Hist. Brit. Ent.,
p. 126, Tab. xvi.. Fig. 8 ; Lynceus sphericus, Norman and Brady,,
Mon. Brit. Ent., p. 48, PL XXI., Fig. 12). Next to Simocephalus
vetulus this is the commonest of the Cladocera of Wanstead
Park.

Chydorus glohosus, Baird (Baird, Nat. Hist. Brit. Ent., p. 127,
Tab. xvi., Fig. 7 ; Lynceus glohosus, Norman and Brady, Mon.
Brit. Ent., p. 47, PL XX., Fig. 5).

I have been assured that Polyphemus pediculus used to be
taken at Wanstead Park, but I have never succeeded in finding
it.

Branchiura.

Argulus foliaceus, Linnseus (Baird, Nat. Hist. Brit. Ent., p.
255, PL XXXI.). The records of this species are simply those of
a few individuals that chanced to be taken swimming freely.

OSTRACODA.*

Cypria serena, Koch. This little species is fairly abundant
at Wanstead Park all the year round, but more especially

* The generic and specific names adopted for this order are in accordance
with the " Monograph of the Marine and Freshwater Ostracoda of the North
Atlantic and of North-Western Europe," by Prof. G. S. Brady and the Eev. A.
M. Norman, "Scientific Trans, of the Royal Dublin Society," Ser. ii., Vol, iv.,
Part ii., 1889, p. 63. No references seem called for in the case of these
animals, as the foregoing monograph contains all the intormation needed.

JouRN. Q. M. C, Series II., No. 32. 12

174 D. .). SCOURFlELi) OX ENTOxMOSTKACA.

SO during the colder months. It has been found in all 'the
ponds.

Cypria ophthalmica, Jurine.

Cypria exsctdpta, Fischer. The admission of this species to
the Wanstead Park list rests upon a single specimen taken in
" The Lake."

Cypris fuscata, Jurine.

.'' Cypris reticulata, Zaddach. — All the specimens seen have
been of the " tessellata '' or immature type. Their reference to
G. reticulata, therefore, although probably correct, is not quite
certain.

JSrpetocypris reptans, Baird.

Gypridopsis vidua, 0. F. Miiller. This is one of the commonest
of the Wanstead Park ostracods, and has been found in all the
ponds.

Notodromas monacha, 0. F. Miiller.

Gandona Candida, 0. F. Miiller.

Gandona fahceformis, Fischer. The Wanstead Park specimens
are not quite typical, but they are considered by Prof. Brady to
belong to this species.

Gandona ahhreviata, G. S. Brady, MS. As already mentioned,
a description of this new species will be published by Prof. Gc.
S. Brady. But it may be indicated here that it is somewhat
similar in side view to G. puhescens, Koch, and G. rostrata,
Brady and Norman, while differing from them in its greater
breadth when seen from above. The young of this species are
of the " albicans " type, and it should be stated that the records
for September, 1890, and October, 1891, rest upon these junior
forms.

Ilyocypris gibha, Ramdohr. This is probably more common
than would appear from the single record, for its mud-loving
habits prevent it from being easily found.

COPEPODA.*

Biaptomus castor, Jurine. This species was not recognized at

Wanstead Park until January, 1892. It has only been obtained

* The specific names of the animals belonging to the genera Diaptomus
and Cyclops are similar to those of the "Revision of the British Species of
Fresh-water Cyclopicla? and Calanidae," by Prof. G. S. Brady, " Nat, Hist.
Trans, of Northumberland, Durham, and Newcastle-upon-Tyne," Vol. xi.,
Part; i., 1891, p. G8. This " Revision" is also publighed separately by
Williams and Norgate.

I>. .1. SCOL'IJFIELl) 0\ KNTOMOSTRACA. 175

from a very small pond — probably the smallest in the Park —
by the side of the " Heronry Pond."

Biaptomus gracilis, G. 0. Sars. A most abundant species at
Wanstead Park. The majority of the males do not possess an
appendage at the end of the antepenultimate joint of the right
antenna, but I have noticed a few specimens in which this pro-
cess was well-marked.

Cyclops signatus, Koch.

Cyclops tenuicornis, Claus. Some evidence obtained by watch-
ing the later stages of development of this and G. signatus leads
me to think that they must still be regarded as distinct species,
and I have consequently kept them apart in this record. They
both occur all the year round, and in all the ponds.

Cyclops Scourfieldi, Gr. S. Brady. Both the type and the
variety described by Prof. Brady have been found at Wanstead
Park, usually occurring together, but not constantly. They
have never been seen during the colder parts of the year. In
further illustration of this preference for a relatively high
temperature, it may be interesting to mention that the typical
form of this species was the only Cyclops found in the Victoria
Regia Tank at the Royal Botanic Grardens, Regent's Park, both
in April, 1891, and April, 1892. The water of the tank on the
latter occasion was about 80° F.

Cyclops vicinus, UTljanin. I believe the active period of this
species is considerably shorter than would be imagined from an
examination of the record appended to this paper. The speci-
mens found in September, 1891, and June, 1892, were from the
" Shoulder of Mutton Pond " — a pond in which this species is
scarcely ever taken. It is possible, therefore, that these two
records are in some way exceptional. There can be no doubt
that at Wanstead Park the main development of this form is
from late November to May. It has never been found in the
" Perch Pond."

Cyclops hicuspidatus, Claus. Two or perhaps more varieties
are here included under this name, one of which is probably
identical with the C. Thoinasi, Forbes, of Prof. Brady's " Re-
vision," but it is a matter of considerable difficulty to definitely
separate these forms, and it is possible that they may be only
stages in the development of one species. Like the foregoing
species, the present seems to reach its greatest abundance

176 D. J. SCOURFIELK ON ENTOMOS'IM.'ACA.

during the colder parts of the year. I have no record of it
from the " Perch Pond."

Cyclops viridis, Jiirine. Both the " gigas " and " hrevicornis "
varieties of this species are common at Wanstead Park.

Cyclops serrulatus, Fischer. Could any British local list be
complete without this ubiquitous and well-marked species ?

f Cyclops macrurusy G. 0. Sars. — The specimens here referred
doubtfully to C. Tnacriirus were all males, and although possess-
ing very long caudal rami, without serrulated outer margins,
may really have belonged to C. serrulaUis. The typical males
of the latter species, by the way, are, so far as I have observed,
always destitute of serrulations on the caudal rami.

Cyclops afinis, G. 0. Sars.

Cyclops phaleratus, Koch.

Cyclops fimhriatus, Fischer. The three foregoing species are
the least common of the genus at Wanstead Park. It is worth
notice that neither of them has ever been taken from May to
August inclusive.

Canthocamptus mmiitus, 0. F. Miiller (Brady, Monograph of
British Copepoda, Vol. ii., Ray Society, 1880, p. 48, PI. XLIV).
All the Wanstead Park forms seem to belong to this common
and widely distributed species.

WANSTEAD PARK ENTOMOSTRACA.
Table I. — Cladooeka.

.Species.

1890.

1891.

"

1892.

M

4

It

u

It

fl

■Si.

ai

u

Il

II

ij

l|

li

II

II

it

u

u

it

II

II

II

r§

ti

u

10

Cladocera.
Sida crystallina .
Daphnella brachynra .

rotunda .
reticulata
quadrangula .
Scapboleboria muoronata

„ (var. oornuta)
SimoCopbaluB vetulus .
Daphniapulex . . .
„ longispina

;; SSa i ;

lioaniina lonRlroatris .
MiuTothrix laticurnis .
llyocrjptusBordiduB .
KMrv.TTCua lamellatuB .
.'\,n.],v,usharpiD.
C.in.pincricuBniaururuB .
I.ryiliniii acanthocercoides .
tiiuptukberis lestudiuaria .
Aloua guttata .

„ tenaicandis.

„ qnadraugulariB . . .

,',' intermedia.' .' '.
.'\l..nolla nana . . . .

.,' unc'inalus ' '. '.
reraoanthtt trunoata .
ChydoruB sphcrious .

*

:

I

1

I

••

I

::;

":

I

■■■

.'.'.

*

:

I

...

":

■

■;

:

...

I

'x'

6

U

IG

18

3

22

19

16

^

7 6 ! 10

9

1.

18 l.S , 16

17 10

«

11

U 16

17

21 : is

19

WANSTBAD PARK ENTOMOSTRACA,
Table II.— Branchiora, Ostracoda, and Copepoda.

Species.

1890.

1891.

1892.

^1

-1

5 =

11

II

11

it

!

S

11

iljil

II

11

11

II

tm

u

11

Ij

it

2.

ll

II

u

BBANCeiUBA.

Argnlns foliacens

OSTEACODA.
Cypria Serena .

,, ophthalmica

„ exBculpta.
CypriB fuBcata .

„ reticulata?
ErputocypiiB rcptaiiB
CjpridopsiB vi.lua
Notodronma moiiacba
Candona Candida

„ fabaitor.niB
"abbreviata'
IlyooypriB gibba

COPEPODA.
Diapton,aB castor
graoil.B
^y'''"P«3_atu.^^^

" .Sccun-fioldi
,. , „ (var

'.', vindis' .
., senulntuB

", affluis""

„ phnleratnB

„ flinbriatus

Canthooamptus miiiut

)

9

8

7

5

...

T

2

6

:

::.

I

;:

f

:.

'x

:.

;

:.

:

I

^

«

...

X

:::

I

.:

:

2

1

6

6

7

4,

4

^

5
5

3

5

2

5

7

I

4

4

X

4

5

5

10

10

8

9

11

' '1

6

8

9

8

10

8 7

7

7

9

11

12

8

9

7

9

8

p. J.

SCOURFTELD ON EXTOMOSTRACA,

177

02

c3

d

c3

c3

45

=3

d

a

a

?o§

-^

fl

a

a

'o

s^

^

CT

a

t»

01

CQ

c«

c3
■5

tfi

tn

fcfl

'^

c3

13

§.

t^lS

c3 :; :; :;

.5

o

-as

a.

:;

Oi

«o

02 02

;-i

B. c3 cc p a ^

§.2

o
1 >^

s:^ « 5 =

17S

p. J. kScourfielp ox entomostraca.

WANSTEAD PARK ENTOMOSTRACA.

Diagram showing the Seasonal Distribution of the Cladocera.

(1) Total number of species — Upper curve.

(2) Number of species from " Perch Pond" only — Middle curve.

(3) Males and " ephippial " females — Lower curve.

? (Averages taken both for numbers of species and for dates.)

Bb:of
Sgedm

Jan.

Fek

mix.

A^

May.

Jim.

xJli

Aug.

Sep.

Oct.

Nov.

Dea

Korof

20
19
18
17

^
IB

13
12

n

10
8
8

7
^
5
4»
8
2
1

20
19

m
n

16
15
3^
13
12
31"
10
9
8
7
6
6
4
3
2
1

■

A

/

V

A

/

\

■

' ^

\l

V

I

7-

1

'

/

/

/\

/

j

/.

\

/

1

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\

\

/

A

/ /

/

\

/

\

{

/

/

\

4

/

\

/^

n/

/

/

\

/..

/

/

\

\

f/\

s. /

/

/

\

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\J

f

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179

On the Cysticercus op T^nia microsoma and a new
Cysticercus prom Cyclops agilis (Rosseter).

By T. B. Rosseter, F.R.M.S.
Plate X.

(Read November IRth, 1892.J

Cysticercus — (Rosseter) of Tcenia microsoma (Creplin).
Form of cyst globulous.
Diameter of cyst, 0'237 m.m.
Hooks, 10.

Length of hooks, 0050 m.m.
Habitat, Cyclops agilis.

This hitherto unknown Cysticercus (Fig. 1, PI. X.) I found
parasitic in Cyclops agilis, taken from a duck-pond in the
parish of Patrixbourne, near Canterbury. Up to the present
time I have only captured two specimens, and one of these had
evaginated itself in the perivisceral cavity of the Cyclops, the
connective tissue of which formed their nidus. The cuticle of
the cyst is devoid of striaB, neither is it fenestrated. It is
lined with a diaphanous epithelial layer.

The evaginated specimen (Fig. 2) consisted of the rostrum,
scolex, and neck, and when dissected from the Cyclops was still
adherent to the cyst.

The hooks on the rostrum (Fig. 2a) are ten in number, and
from the description and drawing "given by Krabbe * they
correspond with those of Tcenia microsoma (Creplin). Accord-
ing to the specimens in my possession their individual length
is O'OoO m.m., divisible thus : a-b 0'034, a-c 0"050. Krabbe in
his monograph gives them as ranging from 0*035 to 0"061 m.m.
— this measurement he explicitly states is after Pfaff and Olrik
— but in some specimens of the tapeworm taken by him from

* See " Bidrag til Kundskab om Fuglenes Bsendelorme," p. 296, figs. 146-
150.

1.^0 T. P.. IIOS^JKTKR (~)X A XRW CV^TTCKRUS FROM CYCLOPS AOrUR.

Anas fusca in Nov., 1867, lie found the liooks on the rostrum
measured 0*043 m.m., which closely corresponds with my speci-
mens. The rostrum was partially inva^inated in the connec-
tive tissue of the head.

The suckers (Fig. 26) were arranged, as usual, equidistantly
round the scolex, and, although they were in an advanced stage
of formation, they were deficient in the muscular rigidity
which, in. the perfect scolex, enables them to adhere to the
mucous membrane of the duodenum of their vertebrate host.

The neck (Fig. 2c) was short, constricted and bulbous in
contour, and it was attached to the cyst by the fibrous tissue of
the immature primary proglottis, which latter was partially
within the operculum of the cyst.

In neither specimen could I trace the six hooks of the
hexacanth stage, as is usual, on the caudal appendage ; in both
cases this was very short, but I am doubtful if this is the
normal condition.

Cysticercus ? (E/Osseter).

Form of cyst, oval.
Length of cyst, 0*282 m.m.
Width of cyst, 0*255 m.m.
Hooks, 8.

Length of hooks, O'OSO m.m.
Habitat, Gy clops agilis.

I took this Cysticercus (Fig. 4), the only one I have captured,
from the perivisceral cavity of Cyclops agilis^ obtained from
the same pond as before.

The cyst is oval, striate, and very symmetrical in its contour.
The invagination commences Yerj abruptly, and there is a deep
crateriform depression at this portion of the cyst (Fig. 4e).
The cuticular or fluid cavity (Fig. 4c) is very deep, more
especially the posterior or basal portion, where the caudal
appendage h enters the cyst. . This it does through a ring-
collar aperture (Fig. 4^), spreading out inside the aperture
where it coalesces with, and forms an integral part of, the
hypodermis or lining membrane of the cyst (Fig, 4:d). The
parenchymatous tissue was homogeneous in character, so much
so that it was impossible to differentiate the usual outlines of
rostrum, scolex, and suckers in the formative substance. The

T. R. ROSSETER OX A NEW CYSI'ICERUS PROM CYCLOPS AGILIS. 181

width of the cyst was 0*255 ra.m., and the long diameter
0-282 m.m.

The hooks of the future rostrum were eight in number
(Fig. 4), including one which was malformed, that is to say, the
root was aborted. They formed a fascicle and lay obliquely in
the cyst. These hooks are the chief consideration in the
investigation of Cysticercoids. as from them alone is determined
the species of the mature form or tapeworm. In this instance
the extreme length of the hook from the posterior root to the
tip is 0*050 m.m., and is divisible thus : a to h 0*028, a to c
0*050 ; a to 6 being the length from the posterior to the anterior
root, and a to c the whole length of the hook.

At present we are only acquainted with six species of Tcenia
infesting birds, whose rostra bear eight hooks. These are : —

T tenia gracilis 0*077-0*080 m.m.

„ ohvelata ... ... 0*076 m.m.

„ fasciata ... ... 0*057 m.m.

„ fragilis ... ... 0*056 m.m.

,, octacantha... ... 0*036 m.m.

,, lanceolata ... ... 0*031 m.m.

For the sake of comparison of the length of the hook, we may
select from this list T. fasciata and T. fragilis as corresponding-
most nearly in size to the hooks of the Cysticercus under con-
sideration. The Cysticercus of T. fasciata is already known,
but that of T. fragilis is still undiscovered, and on reference to
Fig. 5, hook of T. fragilis, and Fig. 6, hook of Cysticercus (r),
it will at once be observed that there is no similarity between
them.

From the table given below it will be clearly apparent that

the length, both of the root and the barb, in either case, for

there is great similarity between the hooks of T. fasciata and

T. fragilis, is totally at variance with the one in question.

(a-b 0*025 m.m.
Tcenia fragilis j

fasciata

(a-b 0*02,
\a-c 0-0d\

a-c 0*056 m.m.
'025 m.m.
'057 m.m.

ra-6 0*028 m.m.

Cysticercus . . . Cf) -j a.a-a
-^ ^ -' (^a-c OoO m.m.

It is possible that the final host of this Cysticercus will be

found to be either the domestic goose or duck. I am led to

182 'P. B. IJOSSETER ON A NEW CVSTICERCUS FF^OM CYCLOPS AdlLTS.

this conclusion from my previous investigations on other
Cysticercoids, and because no other species of natatory birds
frequent this piece of water.

Description of Plate.

Fig. 1. — Cysticercus of Taenia microsoma. a, cuticle ; h,
epithelium of cyst ; c, fluid cavity ; d, in ves ting-
membrane of embryonic scolex ; e, embryonic
scolex ; /, parenchyma ; g, caudal appendage, x
400.

„ 2. — Evaginated embryo from perivisceral cavity of
Cyclops agilis. a, rostrum with hooks ; 6, scolex
with suckers ; c, neck. X 400.

„ 3. — Hook from rostrum. X 600.

„ 4. — a, 5, c, d as in Fig. 1 ; e, crateriform depression ; /,
hooks ; gr, ring-collar aperture ; li, caudal appen-
dage. X 400.

,, 5. — Hook of Toenia fr agilis, after Krabbe. X 920.

„ 6.— Hook of Cysticercus . . . (?) (Rosseter). x 600.

183

On the Use of Isochromatic Plates in Photomicrography.

By T. F. Smith, F.R.M.S.

{Read November 18th, 1892).

Some months ago a letter appeared in the " English Mechanic"
from Mr. Lewis Wright lamenting the smallness of the avail-
able supply of f.uorite for the production of apochromatic
objectives for the microscope, and further mentioning the diffi-
culty of getting it, as a formidable obstacle to future optical
improvement.

With regard to the truth of the charges made in that letter
as to the firm of Zeiss having obtained nearly all the fluorite
procurable I have nothing to do, but having been engaged for
some time past in experimenting with ordinary achromatic
lenses as applied to photography, the conclusion I came to was
that given certain conditions the total failure of fluorite might
not be so disastrous as it seemed.

My reasons for arriving at this conclusion were, that when
using lenses in which the visual and actinic foci were widely
divergent when used on ordinary plates, the image came out in
sharp focus when isochromatic plates were substituted, thus
raising the possessor of an ordinary achromatic objective to the
level, photographically, of the owner of the more expensive
apochromatic.

Considering the number of microscopists who now register
their results by photographing them, I thought this discovery
of mine was so simple a one that I hesitated to announce it as
something new, but further inquiries convinced me that it was
not so known, and I believe the fact is placed in writing here
for the first time.

Of course, I am aware that the advantage of using isochro-
matic plates has been several times mentioned lately, but being
always mixed up with the use of a coloured screen or other

184 T. F. SMITH ON THE USE OF TSOCHROMATIC PLATKS.

light-filter in conjunction with it, the impression conveyed is
that the sharpness of the resultant image depended upon such
screen or light-filter. To take one single instance. At the
last meeting of this Club Mr. Lees Curties exhibited a bottle
to hold solutions for giving approximately monochromatic light
— such as, for instance, copper chromic solution — and in the
discussion which followed Mr. Houghton Gill said, that with
this solution and isochromatic plates he had obtained as good,
or almost as good, results with a cheap achromatic, as he had
been able to do with an apochromatic objective, used without
the absorption fluid.

Now, I cannot help feeling that there is some confusion
here between cause and effect, and it is to the isochromatic plates,
and not to the solution, that is due the fact that the image in
the negative came out in the same plane as the one placed on
the screen, even when ordinary achromatic lenses were used.
I agree with all that Mr. Grill stated with regard to the results
obtainable with ordinary lenses, but the evidence of the effect
of the solution to me is not conclusive, unless it can be also
shown that the results were different when the isochroma,tic
plates were used only without any ray-filter. I do not wish for
a moment to deny that any monochromatic light will make a
great difference in focus when ordinary photographic plates
are used, but it is isochromatic plates we are here dealing with,
and I wish to prove that, when these are used, no light-filter
whatever is required to produce sharpness of focus ; and for
this purpose I beg to exhibit prints and negatives taken first on
isochromatic, and then on ordinary plates to show the difference
of result. The lenses used were all by one maker — Swift
and Son — and I believe that the Jena glass is used, but no
fluor spar ; but I do not wish to imply from this that other
makers' objectives will not give the same results.

Prints Nos. 1 and la show the proboscis of Blow-fly, taken with
an inch objective at 300 diameters, first on an isochromatic
plate, and then on an Ilford ordinary, and you will see that
while the first is sharp in focus, the second is all fluff. I may
say in justice to this lens that there is but little divergence of
focus when used photographically up to 50 diameters on any sort
of plate, but that does not vitiate my argument that what-
ever difference may exist is corrected by the use of an isochro-

T. F-. SMITH ON THE USE OF ISOCHROMATIC I'LATES. 185

matic plate only. It is not for me to say how tliis is brought
about, but content mj^self with announcing it as a fact, and
leave it to those with more special knowledge to explain why.

Prints Nos. 2 and 2a show the Podura scale, taken at about
1,100 diameters, with a -g^in., and shows the same difference of
result when taken on the two sorts of plates.

Nos. 3 and Sa are prints of Goscinodiscus asteromphalns, taken
at 1,750 diameters with a cheap xVin. oil immersion, and here
the difference in focus is simply that between a positive and a
negative image of the same diatom when taken first on an
isochromatic, and secondly on an ordinary plate, the former
being the image j^roduced on the screen of the camera.

All these were taken without any screen whatever, but I have
other prints here, taken of histological subjects with the same
lenses in which the yellow screen has been used, not, however,
to produce a sharper focus, but to render certain colours in the
objects more or less actinic. Here a screen certainly is neces-
sary, but, as I have often found when leaving it out accidentally,
it makes no difference in the focus whatever.

I can qiiite bear out Mr. Gill's experience that on suitable
subjects almost, if not quite, as good results can be obtained
with ordinary objectives as with the more expensive apochro-
matics, and I may add to this that I have found it a great con-
venience to be able to include more of the object by not using
the eye-piece, but this, with me, only applies to the lower
powers, as I find that when using a wide angled ^in. ory^in. this
way the curvature of the field more than neutralizes the
increased image taken in.

In conclusion, I may say that I bring this subject before j^ou
in no controversial spirit, but only to elicit the truth, whatever
it may be.

186

Address on the Mineralization of the Minute Tissues of
Animals and Plants.

By Prof. W. C. Williamson, LL.D., F.R.S., Emeritus
Professor of Botany in the Owen's College, Manchester.

{^Delivered December \QtJi, 1892.)

Although, Mr. President, you are such an old friend, I never-
theless believe that this is the first time I have been put under
your command, but as I know you will be a very considerate
lord and master, I promise most faithfully to submit to your
authority. But, now, gentlemeu, I am not quite so sure that I am
in equally good humour with some other matters connected with
this little affair. I was going to say that in an evil moment,
I promised your Secretary if an opportunity ever occurred
when I could be of service to the Society which bears the name
of one of the oldest friends of my life, I should be very happy
to place myself at his disposal, and the result is that you have
been drawn here this evening.

I know what the general character of your work is, and I am
afraid that ever since I ceased to be a Rotiferous and Foramini-
ferous man, much of the work I have been engaged upon has
been very foreign to your pursuits here. However, when I
found that I was in for something, the question was, what will
interest a group of technical microscopists, and, Mr. President,
I was almost at my wits' end to think of a suitable subject.
However, I happened of late to have been considering some
matters directly connected with microscopy, and I thought
I might be able to give my address a form which would not be
altogether stupid and uninteresting to you. Anyhow, if I fail,
sir, the fault must be mine and not that of my audience. What I
aim at speaking about is some of the leading processes connected
with the mineralization of plants and animal remains, and the
formation by such processes of what we technically call "fossils.'

FROF. W. C. WILLIAMSON ON MINERALIZATION. 187

Now at the first glance, this is a very simple question, involving
very few and easily understood elements. Of course, there
are certain examples of animal life, and even some cases
in all probability of plants too, in which we find nothing but
protoplasm, which is a wholly soft tissue ; then there are others
in which — like shells and crustaceans — there are various forms
of a hardened external integument or shell — whilst in a third
group you have an internal skeleton clothed externally with soft
tissues. Now, as a general rule, when we speak of fossils we
refer to the hardened structures — we speak of the shells of the
Mollusca, the hardened chitinous skin of Insects, or the internal
skeletons of the higher forms of life.

Let lis take a very simple case ; here (drawing) we have an
organic structure imbedded in soft mud, but which mud under
various subsequent processes of nature became hardened,
excluding the air from the imbedded object. In fact, it became
an organism enclosed in a mould, from the interior of which
the atmosphere was excluded. At a still later period this shell
was exposed to the action of destructive agencies, chiefly in the
shape of acids held in solution in the water of the sea. Sup-
posing that this shell was composed of carbonate of lime and
buried in the bed of the sea the superincumbent water contain-
ing carbonic acid would filter through the mud, and reaching
the shell would dissolve out the lime and leave a defined cavity
behind it. Sometimes this cavity remains unoccupied. At the
Royal Society last night some interesting cases of this kind
were brought before us. Some skulls and other bones of some
Reptilian vertebrates had been thus imbedded, but of which not
a trace of the animal substance remained. But by filling these
cavities with some plastic material, I think gutta percha, Mr.
Newton, of Jermyn Street, was able to represent to us the
reconstruction of such remains of these animals as had originally
filled these cavities.

It is important at this stage of our inquiry to note some of
the facts essential to our comprehension of what took place. In
the simpler case already referred to, an organic, calcareous
structure disappears, and is merely replaced by the same cal-
careous material in an inorganic state. It is known to all
familiar with the simplest elements of chemistry that water
containing certain proportions of carbonic acid is capable of

188 PROF. AV. 0. WILLIAMSON ON MINF.RALIZATIOX.

dissolving carbonate of lime. You are all familiar with that fact
from your knowledge of what takes place in many subterranean
caverns ; water filtering through cracks and crevices of cal-
careous strata on its way to the cavern brings along with it,
in solution, lime that it has picked up in the manner just
referred to. But when such a solution is exposed to the
atmosphere the water again throws down the lime so obtained.
On reaching the cavern and dropping from the roof it becomes
thus exposed. The precipitated lime now coheres to form the
stalactitic pendants that hang from the roof, and what remains
reaches the floor, where it produces the layers and pillars of
stalagmite, as these lower formations are called.

Now this is precisely what takes place in many forms of
fossilization. The original shell had a characteristic structure
of its own. It was replaced by the same chemical substance,
but which was now in a pui-ely mineral form, whether crystal-
line or amorphous. But we have some cases with a yet simpler
form of change, where little or no destruction of the original
object has taken place. I daresay some of you have visited
the celebrated dropping well at Knareshorough, and have seen
the fossil wigs, birds' nests, baskets of eggs, etc., that are
regularly produced for sale at that place. This, however, is
what may be termed fossilization by investment. All the
objects in question retain their normal features, and have
practically imdergone no change beyond receiving something
closely resembling a coat of white- wash. Though this cannot
properly be called fossilization, a result not altogether foreign
to it occurs in Nature. Thus there are objects which are more
or less porous, and when solutions of lime reach such, though
they undergo little or even no change in their outward forms,
the solution penetrates their minute internal cavities and
canals and fills them up. This, again, is little more than
fossilization by investment, since it only invests the surfaces
of the tissues of the organism, instead of replacing them.
But this latter process plays a very extensive part in
the preservation of such forms as are of vegetable origin, to
some special cases of which I shall shortly call your attention,
and some beautiful examples of which will be shown to you at
the close of my observations.

Of the examples of lime thus deposited in the interiors of

PROF. W. 0. WILLIAMSON ON MINKIIA I.IZA IK t\. 189

closed cavities we have two distinct conditions, someti me.'< in
the same cavity. I have at home a magnificent specimen of a
Nautilus from the Mountain Limestone of Craven, in which all
the closed chambers characteristic of the posterior part of that
spiral shell are filled with fine crystalline forms of carbonate of
lime or calcareous spar. This condition is very common
amono:st the fossils found in the limestone rocks.

But, on the other hand, I could show you some fossil
Calamites from the coal measures where the first deposits in
the interior of a large cavity, from which the pith has dis-
appeared, consist of beautiful layers of the fibrous form of
lime, known as Arragonite ; but after a while this formation
has ceased, and the solution in the centre of the cavity has
shot into crystals of calcareous spar.

But cases of a less simple kind are much more numerous.
In these the cavity created by the disappearance of the im-
bedded organism becomes filled with other foreign ingredients ;
these are chiefly lime, silica, and iron. Often no traces of the
original object are preserved. A geologist applying his
hammer to stones of this kind would, on breaking up the
matrix, find a pseudomorph of the object originally enclosed
within it, but which instead of being composed as the original
was, say of lime, was now composed of flint or iton.

Another branch of our subject closely allied to that now
under consideration is that of the protracted preservation and
ultimate transformation of the fossilized objects. It is very
difficult to understand how, in many cases, objects primarily
prone to decay, resisted that tendency sufficiently long to become
replaced by mineral matter. We have already seen that in
many instances they were not preserved long, but in others, as
in many of our Carboniferous fossil plants, every minute tissue
is preserved almost exactly as it was when living. As a rule it
is probable that the process of decay is impeded by the complete
exclusion, in many such^^submarine conditions, of all atmospheric
influence, whether organic or chemical. Anyhow the process
was often arrested sufficiently long to admit of the perfect pre-
servation of the most delicate tissues.

When I was a youth another important observation was
made by Professor Turner, the then distinguished chemist. He
found that the replacement of organic substances by mineral
JouRN. Q. M. C. Series II., No. 32. 13

190 PROF. W. C. WILLIAMSON ON M INKKALIZATION.

materials was aided rather than impeded if the organic body-
exhibited signs of incipient decay. According to him, an
increased affinity between the original organism and the
mineral replacing it was produced by that approach to decom-
position — whether the pseudomorph was to become calcareous
or siliceous. This fact is especially obvious when Silicium is
the material substituted for the original organism.

One of the most interesting of the specimens I have met with
in connection with this mineralization by lime shows another
feature that I have not alluded to, namely, that the matter
which has filled up the cavity has, in many cases, a selective
power of its own ; it will select some tissues to which it will
unite itself most intimately, and pass unaffected through
others. The case to which I refer was one to which my atten-
tion was first called by my very old friend Professor John
Phillips. He gave me some nuts from the bog of Warren Pool,
Ferrybridge. Now these were ordinary Hazel nuts, and on
examining them I found that the outer shell was in the
ordinary state of the shells of nuts that we so frequently dig
out of peat bogs ; but when I came to break this shell and
examine the kernel I found that the lime had passed both
through the shell and its lining membrane or endocarp without
affecting them, but the kernel was wholly replaced by carbonate
of lime ; not only so, but as Professor Phillips pointed out,
the lime must have been deposited gradually, because it
actually broke with something of the conchoidal fracture
which, as you all know, the kernel of a nut will exhibit when
you break it. This, I think, was about one of the very best
that I have seen, but numerous similar illustrations have been
met with showing the selective power that the lime has ; in
this particular instance it had an affinity for the kernel of
the nut, but none for the shell — it went to the heart of the
thing, the attractive element being probably the quasi-colloid
protoplasm.

I must call your attention to another most interesting case
of the fossilization of plants. I have at home a collection of
about 3,000 microscopic sections of fossil plants from the coal
measures of Lancashire and Western Yorkshire, varying from
seven inches in diameter down to others of small size. The
history of these specimens is sufficiently clear. The districts

PROF. VV. r. VVILLfAMSON ON M INKKALIZA riON. 191

in which they are chiefly found are those of which Halifax.
Huddersfield, Ashton-under-Lyne, Oldham, and Rawtenstall
are the principal towns. The district had originally been dry
land covered with a forest vegetation, accompanied probably
by a rich undergrowth, which combined to form a layer of
vegetable matter. This surface sank below the sea level, and
was covered up by successive layers of marine sediment in
which numerous marine shells are still preserved, and in some
of which calcareous concretions are also found. The pro-
bability is that water containing carbonic acid has filtered down
through the mud containing these calcareous elements, and
reached the layer of vegetable matter, the tissues of the com-
ponent plants not having as yet perished. By the remarkable
process of Osmosis illustrated by the late Professor Graham,
the water containing lime in solution penetrated these tissues,
and not only filled their minutest cavities with that alkali, but
invested masses of them in calcareous concretions which for
ever prevented any of the agencies productive of decay from
reaching their most delicate structures.

The elements composing these protective concretions are
chiefly carbonate of lime with a little magnesia and iron.

Leaving the calcified objects, we come to those replaced by
Silica, flint, agate, or quartz. Silicified examples of fossil plants
are common enough, but in order to understand something of
the way in which silicification has been brought about we must
say a word or two explanatory of the way in which the Silicium
has acted. You are all aware that under certain conditions
Silica, or flint, is capable of being converted into a jelly-like sub-
stance, the hydrate of Silicium — commonly called water-glass,
or colloid; if a small quantity of this colloid Silica is put into
a large quantity of water it will dissolve, though it takes an
immense amount of water to dissolve a little of the mineral;
but if in addition you introduce some alkaline element into the
water the solvent power that water has over the Silica is
enormously increased, in which state of solution it will readily
penetrate the interior of complex organized bodies. It is from
Silica in this state, in all probability, that we obtain the well,
known numerous examples of silicified woods that exist. Some
of you are probably familiar with the fact that at Autun and
Saint Croix in France we find fossil plants are so silicified.

192 PKOF. W. C. WILLIAMSON ON MINEKALIZATION.

When yoa go to Egypt you find in the desert regions of the
Wadys Anseri and El Tih to the south of Cairo, fossilized
forests of trees, in some cases with stems 20 or 30 feet in
length, all converted into a form of Silica. Short stumps are
still standing as if they were growing in the sand. Thus we
have here examples where Silica does the same kind of work
that lime does elsewhere.

There is always an obvious natural affinity between the
Silica and organic bodies ; the one has evidently a marked
facility for replacing the other. In the case of these fossil
plants in many instances the Silica has filled all the cavities,
but there is retained, enclosed in the Silica, the tissue that con-
stituted the cell walls and the corresponding walls of the
vessels of the plant. In other cases all these tissues have
disappeared — nothing is left but Silica, and yet there remain
sharply defined the position and extent and arrangement of
the carbonaceous tissues, just as perfectly as when the plant
was in a living state; one of the most remarkable of the
mineralizations of plants.

When we turn to the animal kingdom, we discover some
exceedingly interesting cases of silicification. I have put
under the microscope two preparations from the Foramini-
ferous world. You are all aware that the soft animal
of a Foraminifer is a mere protoplasmic body — it has no vessels,
no skeleton — is nothing but a little speck of jelly-like matter.
Speaking of the animal as retained within its shell, a Rotalia
begins with a central cell, to which is added a second larger
chamber, but connecting it with the first one is a small per-
foration in the partition separating the two segments, and by
a succession of such growths is produced a spirally-arranged
group of segments, connected by a succession of minute necks.

These chambers, when the animal was living and at rest,
were filled with this protoplasm, using a strict physiological
term instead of the now needless one of Sarcode, and we find
that the animal occupies all these chambers in the same way.

Now, gentlemen, when you take some of these dried-up
Foraminifera that you so often get from foreign regions, you
apparently have only the shell, but you can sometimes, after
treating this shell with acid, get the dried animal separate
from the shell. I have on the table, obtained in that way, a

PROF. W. r. WILrJAMRON ON MINERALIZATION. 193

specimen of the animal of a species of Rotalia from the West
Indies, which has drawn in all its threads and tentacles
within its chambered house. Take a flint of the Chalk, so
common in this part of the world, and with a convenient
little hammer chip off the thinnest and smallest flakes of
this flint — the thinner they are the better — put them first
into turpentine and then successively under the microscope.
Persevering in this research, you will accumulate a collec-
tion of minute silicified organisms, including Foraminiferous
animals, some within and others deprived of their shells. 1
have on the table such microscopic animal preparations in both
these conditions. But I have also on the table a specimen, for
which I was indebted, a long time ago, to my old friend and
fellow-worker — when we were together investigating the Fora-
minifera — I mean the late Dr. W. B. Carpenter. It is a specimen
demonstrating the existence in the ^gean Sea of what you are
all familiar with under the name of " Foraminiferous ooze," but
in this particular specimen all the calcareous elements of the
ooze are eliminated; but though the shells have gone, the
animals are preserved in a silicified state — not imbedded in
Silex, but the animals have shown their affinity for Silica by
allowing their protoplasm to be replaced by that substance.
Just fancy an Amgeba capable of being silicified ! There would
apparently be no difficulty about the silicification of the Amaeba
if put under favourable circumstances, because it is not more
highly-organized than these Foraminifera are. Here we have
a demonstration of the close affinity that Silica and animal sub-
stances have for one another. But in addition to the above
states, we further find in these flints other Foraminifera, in
which not only the protoplasmic animal, but also the calcareous
shell is replaced by Silica.

On turning our attention to the larger fossils found in the
Chalk, we shall discover that the same affinity of Silica for organic
matter is shown in a large number of them. Thus, in many of
the Echini that you get from the Chalk, such as the genus
Spatangus, etc., their shells still retain their normal Carbonate
of lime, but the animal in the interior has disappeared and been
entirely replaced by Silica.

One more example of mineral replacement may be quoted, in
which iron is the replacing material. This is seen most

194 PKOK. W. U. WILLIAMSON ON MINEKALIZATION.

frequently when the strata in which the fossils are preserved
are shales and clays, like the Oxford clays and the Liassic beds
on the Yorkshire coast, in which many of the calcareous shells
of the Ammonites have been converted into iron pyrites, which,
in the old days, we used to call Sulphuret. The calcareous
shell is here replaced by this Sulphide of iron. Vegetable
substances are equally liable to be replaced by this Sulphide
of iron. I have on the table a specimen of a Stigmaria — one of
the Sigillarian and Lepidodendroid roots — where the Sulphide
of iron has taken the place of everything else. Sections of
these things are, under the microscope, as black as ink, but
with a common pocket lens you will be able to see minute
particles of this Sulphide of iron, not only covering the cell
walls on their outsides, but the solution of the metal has
passed, by osmosis, through cell walls, and in like manner
covered their inner surfaces, whilst in other examples the iron
has substituted itself for the vegetable substances. Whether
the whole of the organic carbon has disappeared I cannot
absolutely determine, but, so far as I can see, there is not a
trace of it left. I have tried, by making sections of some of
these specimens with a view of discovering whether or not any
traces of organic carbon were left, but this does not materially
affect the question under consideration. Examples of silicified
plants on the table show perfectly clearly there is no carbon
there, and it does not particularly matter whether there was
any left or not, because whilst in some all the original carbon
certainly disappears, in other cases it as certainly does not.

The conclusion to be arrived at from this hasty treatment of a
very complex subject will be somewhat as follows : — Numerous
objects have either lived in water, or on land which has sunk
beneath water. As they died, their remains sank to the sea-
bed, and there they became imbedded in the sand, mud, or
whatever materials that floor consisted of. Those materials
became consolidated into limestone, sandstone, or shale, sand-
stone being but consolidated sand, whilst shale is mud so
altered, and limestone was, in large measure, Foraminiferous
and Coralline ooze. Enclosed firmly in one or other of the
above consolidated materials, as the sculptor prepares for his
metallic casting by enclosing his clay model within its plaster
mould, each organism underwent more or less of change. In

FROF. W. ('. WILLIAMSON UN MINERALIZATION. 196

some cases, as amongst shells and the bones of animals, these
changes were limited to the disappearance of the decomposable
organic matter, leaving the mineral elements unaltered. Still
further changes depended upon the varieties of local circum-
stances and conditions existing in each individual case. The
imbedded object might undergo no change. It might for a time
only have any cavities that existed in its substance, large or
small, filled up by inorganic matter introduced into those
cavities in a state of solution, and left there either in an amor-
phous or a crystalline condition.

In other cases, the substances composing the buried organism
might be partially or wholly removed, either in a solvent or a
gaseous condition, and the vacant spaces be reoccupied by
foreign materials as before. All these varying results must
have been dependent, partly upon differences in the character
of the matrix within which the organism was imbedded, partly
in the substances dissolved in the superincumbent water, and
partly upon differences existing between the affinities of the
substances so dissolved and those of the buried object which
they were about to replace.

196

On Two New Species of Macrotrachelous Callidin^.
By David Brtce.

{Read January 20th, 1893.)

(Plate XT.)

Before entering upon the description of the new forms, I take
this opportunity of referring to two points as to which some
misconception may exist. The first arises in part from an error
of my own. In my former paper on the group of Macrotrache-
lous Callidinae I mentioned a species, which is not uncommon,
as " the form described by Mr. Milne as the Callidina elegans of
Ehrenberg." T should have referred to it simply as the Macro-
trachela elegans of Milne, for, in point of fact, that author, as I
have more recently stated, had come to the conclusion that
Ehrenberg's genus Callidina represented Philodinasa, having
that type of corona which we now recognize as distinctive of
the genus Adineta. It follows from this that his two species,
M. elegans and M. hidens, were believed by him to be distinct
from the two species of Callidina described previously under
the same specific names. Yet Dr. Hudson, regarding all the
Macro trachelas of Milne as so many species of Callidina
(Rotif. Supp., p. 59), proceeds (Index, ibid., p. 64) to refer
M. elegans to the Callidina elegans of Ehrenberg, and M . hidens
to the Callidina hidens of Gosse, being obviously misled by Mr.
Milne's unfortunate choice of names Having compared the
descriptions given in " The Rotifera " (i., p. 109) with those
furnished by Mr. Milne, and having found forms agreeing with
both of the latter, I have little doubt that all four species are
distinct, and T would suggest that Mr. Milne should remove the
present block by bestowing new names upon his forms. I ven-
ture to add, as my own opinion, that the fact that a specific
name has been already employed should be a supreme objection
to its use for a new form of any conceivable propinquity of

TWO NEW iPEClKS OK MA<,'ROTRA0HEI-0US CALLIDIN^. 197

relationsliip, however suitable that name should otherwise
appear.

The second point is the use by Dr. Hudson of the term
oesophagus in the specific characters given (Supp., pp. 9-10) for
Gallidina symbiotica and C. Leitgehii. The former he states to
possess an " oesophagus without a loop," the latter, an " oeso-
phagus with a loop." The portion, however, of the alimentary
tract where the loop is present in G. Leitgehii, is that between
the mouth cavity and the mastax, and is better identified as the
buccal funnel, gullet, or pharyngeal tube, whereas the oesophagus
is that portion following the mastax, and through which the
food is conducted in its passage from the mastax to the
stomach. As Dr. Hudson himself (Rotifera, i., p. 7) has
defined it in this sense, his use of it to denote the pharyngeal
tube is clearly a slip.

Gallidina symhiotica, therefore, has the pharyngeal tube
without a loop, and G. Leitgehii has the pharyngeal tube with
a loop. So far as I am aware the loop occurs in no other
species of the genus.

The occurrence of two more specimens of Gallidina spinosa
enables me to add to my former description of that species that
the rami have respectively three and two teeth, giving the
formula f, and that the species is viviparous. The latter
character, although possessed by several of the commensal
Callidinee, has not yet been noted among the macrotrachelous
group, and the doubt is thereby raised as to whether the species
is not in reality a Philodina, in which the eyes have escaped
detection. I hope, therefore, that whoever may next find it will
look closely for the eyes, for the number of toes, -and for the
presence of a foetus. In Philodina the eyes are frequently very
difficult to see, from the paleness of. the colouring matter ; and
as this species has a very rough and opaque skin, it is the more
possible that they may have escaped my search.

The two new species exhibit extreme departures from the type
of ciliary organs normal among the Philodinadfe. For my present
purpose that type may be said to consist of two ciliary wreaths,
of which the principal is borne round about the peripheries of
the dilated and cushion-like tops of two prominent fleshy lobes,
placed side by side, and separated by a conspicuous gap. In a
directly dorsal view, one observes at the outer lateral bases of

198 0. BKYCE ON TWO NEW SPEClKt? OF

these lobes a collar-like ridge, the dorsal continuation of the
margin of the mouth. By measuring the greatest breadth,
across the two fully expanded lobes, and again at the edge of
this collar, we can classify, with some accuracy, the varying
proportions of the ciliary organs.

In Philodina the two discs are usually much wider than the
collar, but as we examine the Callidinse we find a series of
gradations passing from the broad Philodina-like discs of
quadricornifera and other large forms until we reach, in this new
species, Callidina pusilla, a form in which the discs are barely
one-half the brea^dth of the lip margin. It is no longer the
collar which we can measure, we have to take our dimension
from side to side of the lip itself. The conspicuous gap between
the lobes has disappeared, and there remains but a shallow
notch, merging into a shallower groove, to mark the two-fold
structure of the almost united discs. The cilia of the principal
wreath no longer produce the appearance of a revolving cog-
wheel, but rather that of so many lashes, whose free ends are
rapidly and independently whirling in circles as though swung
round from their respective bases, an appearance probably as
illusory as the other. They give the impression of being rather
longer and more vigorous, if possible, than usual, as though to
compensate for their presumably smaller number. I have not
observed the animal attempt to swim, but these cilia, at all
events, have no difficulty in fulfilling their important duty of
drawing food particles within reach of the secondary wreath.
In consequence of the reduced proportions of the discs, and the
retained height of their pedicels, the secondary wreath is
placed, as to the principal wreath, at a much more oblique
angle than is normal. The species which approaches this most
nearly in its restricted disc surface is C. reclusa, one of the two
interesting species found dwelling in the cells of Sphagnum,
and it is curious to note that pusilla is also a tube-dweller ;
indeed, it was this species which I referred to in my earlier
paper as a tube-dwelling species, which I could not identify.

Recently, however, I have succeeded in establishing a colony
in a trough whose sides have become coated with a growth of
some very minute alga. Here and there specimens of pusilla
have formed little tubes, distinguishable by their brown
colour from their floccose-like surroundings. It is almost a

MAGltOTBACHELOUS OALLIDIN Jfi. 199

euphemism to call these habitations tubes, but in the larger
examples there does appear to be an elastic tissue forming the
basis of the structure. Externally it is rough, as though coated
with and formed by particles brought together by the action of
the wheels. I have not, however, observed any movement of
the Rotifer suggestive of conscious tube-building, nor have I
seen the manner of the disposal of the faeces, which I have
thought might perhaps be the cause of the brownish colour of
the tube. Individuals without a sheltering tube are occasionally
seen nestling among the flocculent growth, but I believe that
these are either very young specimens or such as have been
recently disturbed or otherwise induced to leave their habita-
tions. Deserted tubes are not infrequent, but are usually small,
and often contain a single egg.

My colony has existed for some three months, and, whilst the
increase in numbers has been slow, it has been maintained. Yet
it has been far outstripped by that of C. consfricta, a more
nomadic form, which has been its table companion in captivity.
This suggests that pusilla is less hardy, or is less prolific, or
that its eggs develop more slowly than those of its competitor,
whose eggs, indeed, are deposited wherever the parent may
happen to be, and left quite unprotected. The smaller size of
pusilla and its smaller trochal discs do not, I think, account for
the difference, for in the same trough I have several other larger
forms with spreading trochal discs, and none of these show any
increase at all. C. pusilla has one structural peculiarity
occurring in several other species, but not mentioned by any other
writer than Dr. Zelinka, who has noted its presence in C.
symbiotica. This is a peculiar hillock-like sw^elling upon the
dorsal surface of the first joint of the foot, arising apparently
from a local thickening of the hypodermis. Longer than broad,
and placed lengthwise to the body-axis and in the central line,
it is best seen in lateral view, when it appears as a low mound
rising gently in the front and extending nearly to the hinder
boundary of the joint, where it terminates rather abruptly.

In the second new species the trochal discs have become
developed into two horn-like processes, which extend forwards,
and are so curved as to suggest at once the head of the male of
the stag beetle. I propose for it the name of cornigera. There
have been no forms discovered intermediate between this very

200 1>. BBYCE ON TWO NEW SPECIES 0>'

abrupt departure and the type, and I anticipate that ultimately
a new genus must be created to receive this species. Biit I have
only found one single specimen, and although I kept it for some
fourteen days I failed to get any precise observations of the
disposition of its ciliary wreaths. The creature was very timid
and sluggish, and on the few occasions I saw the wheels pro-
truded it baffled my efforts by either erecting itself until one'
could see into the mouth, or leaving hold it would swim away to
be presently stopped by coming full tilt against some obstacle.
Over and over again it was brought to a stop with its horns
against the glass forming the bottom of the cell, and there it
w^ould continue for some minutes, the wheels in motion and the
foot waving directly in the line of sight. Thus standing either
upon its foot or upon its head it constantly frustrated my
designs, and I could only obtain approximate sketches and
cursory notes.

The lateral edges of the discs are produced forward as two
horn-like processes, which at first receding from each other are
yet so curved that towards the tips they have begun to
approach and do approach as closely as at their bases. For
some three-fourths of their length they advance almost in the
plane of the body, but from thence they are decurved till they
point nearly at right angles to their original plane. I could see
no gap between the two halves of the cilia-bearing surface, nor
any break in the line of cilia, or in the line of the discs. That
portion which most nearly corresponded to the usual trochal
discs was here replaced by a somewhat concave surface, the
upper margin showing in dorsal view as an approximately
straight line joining the bases of the horns. The concavity of
this surface seemed to be continued some little way forward
along the inner side of the horns, and, as well as I could see,
the cilia of the principal wreath were disposed along the whole
dorsal margin of the concavity, and, at least, a great portion of
the ventral, extending thus not merely across the front, but
even some little distance along the inner margins of the horns
on either side. I could not define any portion of the secondary
wreath nor the form of the mouth cavity. In the act of pro-
truding the wheels one horn was pushed forth before the other,
as though in retraction it had been folded across and outside it,
'jooth being bent inwards from their bases.

MACROTKACHELOUS CALLIDlNiE. 201

Whenever the wheels were withdrawn there became visible
the familiar outline of a Callidina, a little stouter than some
forms, but not now presenting any obvious peculiarities.

I noticed that the double flap, terminating the column tip,
was rather more developed than usual, but the cilia beneath it
were not particularly powerful or conspicuous. The dorsal
surface of the column had a perceptible thickening of the
hypodermis very noticeable in side view.

The third segment, to which belong the mouth and the
trochal discs, seemed a little bulkier than is usual, and the
next carried a very short antenna, about one-fourth of the neck
thickness.

There were the usual skin-folds, dorsal and lateral, lightly
marked, whilst the foot had the ordinary short conical spurs.
I did not ascertain the mastax formula.

Callidina pusilla^ n. sp.

Sp. Ch. — Small, rather slender, trochal discs, about one-half
breadth of mouth margin, sulcus reduced to shallow notch,
discs on pedicels rather higher than breadth of discs. Mastax
formula f , food in pellets, digestive action a periodic heaving of
stomach, upper joint of foot with mound-like swelling. Spurs,
two short cones. Inhabits brownish, rough-looking tubes.

Habitat. — Moss from Epping Forest.

Length. — Largest specimens about li^jth inch, extended.

Callidina cornigera, n. sp.

Sp. Gh. — Trochal discs apparently without gap, laterally
produced into two horn-like but fleshy processes, whose bases
are furnished on inner face with cilia, forming part of principal
wreath. Antenna very short, one-fourth of neck- thickness.

Habitat. — Moss from roadside, near Bognor.

Length. — Extended about j^^th inch.

Description of Plate.

Fig. 2. — Callidina pusilla, wheels protruded, ventral view.
„ 2a. — „ „ wheels protruded, lateral view, in

tube.
• „ 3. — Callidina cornigera, wheels protruded, dorsal view.
„ 3a. — „ ,, lateral view of horns,

„ 86. — Column as extended in crawling.

202

On a Diatomaceous Earth from Guatemala, and the Occur-
rence OP Marine Diatoms in Fresh Water.

By Arthur M. Edwards, M.D., Newark, N.J., U.S.A.

(Read January 20th, 1893.)

Having received from Mr. G. C. Karop a sample of earth
labelled " Diatomite, Guatemala,"* I wisli to report on it at
this time, more especially as it gives me an opportunity of
making known the results I have arrived at insstudying the
Diatomacese in connection with the subject of the occurrence of
marine forms in fresh water.

This brings me to speak of the origin of Diatomacea3, whether
fresh water, brackish water, or salt water or marine. The
Guatemala earth is a white powder, and, although the geology
of it has not been studied, or at least has not been communi-
cated to me,t I should judge from the examination of it micro-
scopically that it is an example of which we have many in the
northern United States or Champlain area, that is to say,
deposits which have been thrown down during the post-glacial
or iceberg period, when the ice formed in the glacial period
was melting, and warmer weather succeeded, and a fi^esh water
sea, with DiatomaceJB, lived and died, their siliceous shells
being deposited on the bottom. I judge this to be the case by
comparison of it microscopically with those deposits with which
I am familiar in Canada, the United States, Germany, Great
Britain, Italy, and Sweden. It is purely siliceous,;}: and con-
sists of the following forms : —

Amphora ovalis, Ktz. Melosira undulata, Ktz.

Biddulphia Icevis, Ehr. Navicula afflnis, Ehr.

Cocconeis lineata, Ehr. „ hacillum, Ehr.

„ placentula, Ehr. „ cryptocephala^'Ehr.

* Obtained from Mr. A. Ashe.

f Mr. Ashe informs me that inquiry has been made on this point but
without result. — Ed. " Q. M. C. Juuru.''
X See Aualysis at end by Mr Ashe.

A. M. KDWAKDS ON A (>lArOMA<;KODS KARTH. '203

Cocconeis Mexicana, Ehr. Navicula cuspidata, Ktz.

Cymatopleura elUpHca, var. „ duhia, W. G.

Bihernica, W. S. „ pygmcea, Ehr.

Cymatopleura solea, A. de B. „ sculpta, Ehr.

Cymhella cistula, Hempr. „ viridis, Ehr.

Epiihemia gihha, Ehr. Bhoicosplienia curvata, Ktz.

„ turgida, Ktz. Surirella hiseriata, A. de B.

Fragillar'ia virescens, Ralfs. „ spiralis, Ktz.

Gomphonema gracile, Ehr. Synedra ulna, Ehr.

Melosira granulata, Ehr.
The Cocconeis lineata, Ehr., is a large form of Cocconeis placen-
tula, Ehr., as is seen plainly in this sample. But the Cocconeis
placentula, Ehr., in it has the markings coarse, showing the
transition into a salt water form, or Cocconeis scutellum, Ehr.
The Navicula diihia , W. G., is plainly a form of Neidiiim, E. P.
(E. Pfitzer. Untersuch. ii. Ban und Entvvick. d. Bacillariaceen
(Diatomaceen) 1871), or Navicula firma, Ktz. Uhoicosphenia
curvata, Ktz., has a var. viarinum, W. S., which is marine, but
this is'not the point on which I wish to dwell. What I wish
to indicate is the occurrence of Biddnlpliia Icevis, Ehr ., a form
hitherto ranked as marine in this, a fresh water deposit. Now
this form is very common in the United States. As marine it oc-
curs on the coast from Cape Cod round into the Gulf of Mexico.
As brackish it is found in the salt marshes of Nebraska and other
western localities. As a fresh water form it occurs in a pool
near Newark, N. J., and in a spring near Coney Island, N.Y.

Fossil it is found in the fresh water deposit of Guatemala,
and at Hatfield Swamp, N.J., which I will describe below.
And as a brackish fossil form it is found in a deposit called,
for want of a better designation, Champlain, near Newark,
N. J., and which I propose to describe in a further paper.

Coccon eis Mexicana, E hr., is a very small form, looking like
Navicula exilis, Ktz., only smaller, with superior valve having
median canal, and fastened by the valve to an alga or stone, as
is the case with those in the Guatemala Diatomite. In this
latter, besides the Diatomacese, there is only found fragments
of what I have already judged to be pumice. These are com-
mon in the Diatomaceous deposits- on the Pacific slope, and
upon this pumice is the Cocconeis Mexicana. This shows that
a volcano existed near by where the Diatomite was formed. C.

204

A. M. KDWAKUS ON A DlATOMACEUUS KAKTH.

Mexicana, by-the-bye, is C. Americana^ Ehr., when the striae are
fine, or as Ehrenberg says in the American tabulae (Abhand.
Berl. Ak., 1843, p. 123), " striis obsoletis."

Besides the Guatemala Diatomite 1 wish to report on a clay
from Hatfield Sw amp, N.J. , which is two miles and a half long
by one~and a half broad, and three feet eight inches deep,
which contains also, besides fresh water forms, such as Navi-
cula viridis, Ehr., in its various forms of nobilis, gigas, and
others, and Eunotia gracile, Biddulphia Icevis, Ehr. It has also
two truly marine species that have never been found in fresh
water ; these are Actinocyclus Balfsii, W. S., and Gam pylodiscu s
echineis, Ehr.

~^Now" the first water that fell was rain, fresh water, and
Diatomacese grew, died, and their shells were deposited on the
floor of the sea, or ocean, as fresh water forms. Thereafter the
fresh water dissolved the salts that were present, and became
marine or what we call salt water. The Diatomaceas were
gradually changed as the water became more and more salt,
and became marine species, so that the Diatomaceae appeared
at first as fresh water forms.

Analysis of a Sample of Diatomite from Guatemala.
By Mr. A. Ashe.

Moisture
* Combined Water and Organic Matters
Oxide of Iron (Ee.Og)
Alumina
Lime...
Magnesia
Potash
Soda...

Phosphoric Acid
Carbonic Acid
Sulphuric Acid
Chlorine
Silica

7-610

6-570

3-028

4-872

-515

122

•104

-146

-118

•240

None

•010

76665

100000

* Containing nitrogen in the organic matter, '034.

205

On a Method of Preserving Rotatoria.
By Charles Rousselet, F.R.M.S.

(:Read January 20th, 1893 J

The inability of preserving the various and beautiful forms
of pond life in anything like the appearance they present in life,
owing to the thinness of their tissues and the enormous con-
traction they undergo when put up in preservative fluids, has
always been felt with much regret by most observers. It often
happens also that a form is found in great numbers on one
occasion and then not again for many years afterwards, and
the utility, therefore, of being able to preserve some type
specimen for future reference, and for the elucidation or veri-
fication of anatomical details, cannot be overrated.

During last season I made a large number of experiments in
order to try and solve this problem with regard to Rotifers.
My efforts in this direction have been suflnciently successful to
induce me to place before you the methods I have employed, in
order to allow others to experimenting the same direction.

The Rotifers I have prepared are fully extended, very nearly
as transparent as in life, with their cilia, muscles, nerve threads
— and even the minutest anatomical details — such as the
vibratile tags and the very fine flagella attached to these tags
in Asplanchna — f nlly preserved, and often rendered more easily
visible.

After carefully considering the various methods in use for
preserving animal tissues, which are so clearly set forth in Mr.
A. B. Lee's " Microtomists' Yade-Mecum," I decided to follow
an exclusively watery process, that is, one that would prevent
the dehydration of the specimen, which appears to be the chief
cause of the shrinkage. Alcohol, therefore, and all fluids
absorbing, or much denser than, water have been avoided.

The whole process consists of four stages, namel}^ narcotizing,
killing, fixing and preserving, which I will describe separately.

Narcotizing. — In dealing with Rotifers the greatest difficulty

JouRN. Q. M. C., Series II., No 32. 14

206 C. ROUSSELET ON A METHOD OF PRESERVING ROTATORIA.

to contend with is the killing in an extended state ; few other
animals can contract into such a shapeless mass when we
attempt to kill them by ordinary means, such as alcohol,
poisons, heat, etc. ; even the quick acting osmic acid is not quick
enough to prevent a complete collapse. It is, therefore, neces-
sary to have recourse to a narcotizing agent which will act very
slowly and paralyze the nerves and muscles sufficiently, that
when the killing fluid is added the animals will no longer be
able to contract. Such a narcotizing fluid, eminently suitable
for Rotifers, has been found in a weak watery solution of
hydrochl orate of cocain of 1 to 2 per cent., first proposed by E.
F. Weber for keeping quiet very active Rotifers when under
observation, and for which purpose it answers admirably. If
a small quantity of this solution be added to the pond water in
which the Rotifers are, they will at first not be affected at all,
but continue to swim about as usual. After some minutes
(5 to 15) their motion will become slower and slower, and in
the most successful cases they will finally sink to the bottom of
the trough fully extended, with the cilia vibrating but feebly.
The Rotifers will not be dead yet, and if an attempt be made
to kill them at once in that state they will most likely contract
and be spoilt. It is necessary to watch them under the micro-
scope until the cilia have just ceased to vibrate, and then, at
least in the majority of species, is the right moment to kill
them, as explained below. The action of cocain varies greatly
in different Rotifers ; some species, such as Asplanchna, can
stand a good deal of the anassthetic, while others, such as
Stepbanoceros, are extraordinarily sensitive to it. The
quantity of cocain added to the water must, therefore, be
varied with every species according to requirements taught by
experience. As a general rule I can say, add as little as
possible, but sufficient to kill in about an hour's time ; if the
animals collapse, or show signs of weakness at once, it proves
that too much has been added.

Killing and fixing. — When the Rotifers have been sufficiently
long under the influence of the cocain they are killed with
Flemming's chrorao-aceto-osmic acid mixture,* which fixes them

* Flemmingr''* fixing solution consists of —

1 per cent, chromic acid 15 parts

2 „ osmic acid 4 „
Glacial acetic acid 1 part

C. ROUSSELET ON A METHOD OF PRESEEVING ROTATORIA. 207

at the same time. It is essential that the animals should not
be quite dead when the killing and fixing solution is added.
As soon as a Rotifer is quite dead various post-mortem changes
begin immediately to take place in the tissues, first absorption
of water and swelling, then disintegration and decomposition,
and it is evident that in order to preserve the animal in its
natural state, it is necessary to fix the histological elements
before any such changes have taken place. The word "fixing"
implies rapid killing and at the same time hardening of the
tissues to such an extent as to prevent their undergoing any
further change by subsequent treatment with preserving fluids.
The animals remain in the fixing solution a quarter to half an
hour, not longer, small Rotifers rather less ; then the solution
must be washed out with distilled water by changing the
water five or six times. The animals will then be ready to be
placed in the preserving fluid.

Preserving. — The choice of a suitable preserving fluid has been
a matter of some difiSculty, and may possibly still be improved
upon. The required qualities are, that it should not alter the
form and tissues of the fixed Rotifers ; that it should not form
a deposit or crystals ; that it should not attack the cements used
for making and mounting in cells ; and that it should have a
density not differing appreciably from that of water.

Alcohol and glycerine prevent decomposition by absorption
of water ; this means shrinkage in the delicate tissues of
Rotifers, both these fluids are, therefore, unsuitable. Weak
solution of corrosive sublimate, 2 in 1,000 parts, has several
times produced crystals, and has also attacked Miller's
caoutchouc cement, of which my cells are made, and from which
it appears to dissolve out some of its constituents.

I have tried various other liquids with more or less success,
and have come to the conclusion that the best preserving fluid
is simply distilled water rendered antiseptic by a trace of the
fixing solution (about 8 drops of Flemming's solution in an
ounce of water), giving the slightest possible yellow tinge to
the water. Rotifers mounted in this solution for six months
have kept very well. The chromic acid appears to give a slight
yellowish colour to the tissues, but otherwise they remain very
fairly transparent ; it is possible, however, that with further
experience a still better preservative fluid will be found.

208 C. ROUSSEf.RT ON A METHOD OP PRESERVING ROTATORIA.

Bearing in mind all that lias been said with regard to nar-
cotizing, killing, fixing, and preserving, I will now give a
detailed example of my procedure by explaining how I proceed
in preserving Asplanchna priodonta, and then indicate such
modifications as are necessary for other Rotifers, for each species
has its peculiarities and affinities, and must be killed in a
slightly different manner ; for the same reason it will be neces-
sary to separate the various forms, as one will hardly succeed
in preserving satisfactorily a number of different species at
the same time, but few as well as a large number of indi-
viduals of the same species can be treated collectively by my
method.

Asplanchna . priodonta is usually found in great numbers.
After isolating some scores or hundreds in a small trough of
clean water I add coca'in solution by degrees, in all about
one-tenth to one-eighth the quantity of the water. This is
measured roughly in this way : if I know the trough contains
five pipettes full of water, I add one-half pipette full of the
solution. The Asplanchna wHU not mind the cocain at first,
but after a time their movements will become slower, and in
about half-an-hour's time they will have sunk to the bottom of
the trough. The trough is then transferred to the stage of the
microscope, where it will be seen that the animals are perfectly
extended, weakly vibrating their cilia, but otherwise motionless.
In order to find out the right moment to kill them, I take out
a few from time to time on a slide and add one drop of the
fixing solution. As soon as they allow themselves to be killed
without contracting a small pipette full of the fixing solution
is run down the sides of the trough ; the solution being heavier
than the water will spread in a layer on the bottom of the
trough, covering the Rotifers, killing and fixing them, the
majority in a perfectly extended state. They are left there for
fifteen minutes, and then must be washed thoroughly with five
or six changes of distilled water, either in the same trough or
in a test tube, to remove all trace of the fixing solution. The
animals will then be ready for putting up in preserving fluid.

Asplanchna priodonta contracts slowly just before dying in
the cocain solution, and must, therefore, be killed quickly, and
before this contraction takes place. Asplanchna Brightwellii
dies in a perfectly extended state, but must also be fixed before
being quite dead to prevent post-mortem changes.

C. ROUSSELET ON A METHOD OF PRESERVING ROTATORIA. 209

Pedalion and the various species of Brachionus, Anurea,
]S^otliolca, and similar forms offer no diflB.culty. Limnias
ceratophylU stretches as far as it can out of its tube under the
action of cocai'n, but then contracts slowly and becomes opaque
before dying; the fixing solution must, therefore, be added
before the contraction begins, and when the cilia are still in full
motion.

Floscularia aud Melicerta are very sensitive to cocai'n ; add
little to the water and fix before the cilia have ceased to move.
After having been under the influence of cocai'n they will not
contract when killed quickly.

Stephanoceros is excessively sensitive to cocain, and only a
trace of it can be added to the water, under the influence of
which it must remain for a long time (hours) before it can be
killed. The long cilia on the arms seem to retain their vitality
the longest, and are thrown in violent and utmost confusion by
a little too much cocain, even when the animal is no longer
able to retract into his tube.

The soft bodied forms of the genera Philodina, jS'otommata,
Furcularia, etc., are more difficult of treatment, and as they are
not generally found in numbers, experience in their preserva-
tion can only be gained very gradually.

With some Rotifers, especially Euchlanis, T have had no
success, whilst I have not yet had an opportunity of experi-
menting on a number of other species.

I trust, however, that the indications given in this paper
will enable many, after gaining a little experience, to preserve
the new or interesting forms they may meet with, and that
eventually it will be possible to make a complete collection of
type specimens of the Rotifera.

210

PRESIDENT'S ADDRESS.
By the Rev. W. H. Dallinger, D.Sc, LL.D., F.R.S., F.R.M.S.,

ETC.
(Delivered February 17 th, 1893.)

Gentlemen, — The rapid movement of time brings ns to the
close of the fourth year in which, by your courtesy, I have
occupied the position of your President. It has been in every
sense a pleasant period, and to preside from time to time over
your meetings, enriched as they have been by monographs and
papers evincing quiet and unostentatious sincerity, and the
following discussions, showing acuteness and search for truth,
has been to me at once a source of interest and profit.

In receding to-night from the position that I have so long
occupied I do so with more than complacency, because of the
perfect satisfaction, not only I, but all of us, must have in the
suitability, competence, and thorough efficiency of the gentleman
by whom I am happily to be succeeded. All of us know in Mr.
Nelson a gentleman, a microscopist of the first order, and one
whose knowledge of the present position and past development
of the instrument is thorough, and after having become by four
years of close observation cognizant of the unique and important
position occupied by this Club, it is pleasant, whatever my own
shortcomings may have been, to find myself succeeded by one
who is not only a friend, but a friend whose competence com-
mends itself to all.

In saying a few parting words from this chair, the embarrass-
ment arising from the abundance of the material undoubtedly
presents itself, but at the same time there are limits involved in
the position more easily felt than expressed.

One may, perhaps, glance briefly at one or two of the in-
cidents connected with a year of direct and associated work in
regard to our favourite science. A mere review of the work
done by the Club can never be thorough enough to be satisfac-
tory, even if it were needed, but a glance at some of the

PRESIDENT S ADDRESS.

211

results of labour associated with or attributable to the instru-
uient which we claim as our own may not be oat of place. And
at the outset we have no advance to report either in facilities for
the use of the objectives of great 'N.A. now in existence, nor in
the production of lenses of yet higher aperture.

At present we are at a standstill. Mounting and immersion
media cannot at present be found which will enable us success-
fully to use a lens with a numerical aperture of 2 00, or even
1"60 ; and although there is much help afforded us in the use of
pure monochromatic light, enabling us to use achromatic lenses
more successfully, and both achromatic and apochromatic lenses
with increased aperture, there has been no special advance in
this matter during the year ; but it should be remembered that
this is no real proof that some splendid results may not yet be
obtained from the use of shortened wave-length represented by
apochromatic objectives.

I have been experimenting on the entire group of my object-
glasses, as produced by the best English, European, and
American makers, for the last 26 years, and I certainly have
obtained most curious and even conflicting results ; but the sum
of these practically is, that I gather, what I suppose was
implied in the first presentation of the facts connected with the
scientific use of monochromatic light, viz., that to obtain the
highest results possible with it — to secure the largest theo-
retical and practical aperture with it — we want combinations
of lenses having mathematically adapted curves — in short,
objectives made to give the best results with a definite ray of
the spectrum just as the apochromatic objectives had to be
specially devised and figured to do their special work. Hence
it appears to me that we are not giving monochromatic light a
fair chance until we use, for high- powers specially, object-
glasses constructed to suit its refraction and dispersion. We do
not exhaust the new possibility presented by it by simply
showing its limitations when applied to existing object-glasses.

I should be glad, indeed, if some one of our leading and com-
petent English opticians would address himself to this problem,
adapting lenses for use with the spectral ray that will give the
widest aperture in ordinary media, such as we can use without
violating the conditions which make the life of the organism
under examination impossible. There is a fine field open.

212 president's address.

N'evertheless, in tlie construction of highly-corrected lenses of
high power, without fluorite, there has been and is a distinct
advance, and this is the more important because it means the
production of constantly lower-priced lenses with high quality —
the very condition needed to promote the progress of micro-
scopy.

And in this relation it would be an impropriety not to
remember the valuable contribution to the improved theory and
practice of lens-making provided by Professor Silvanus Thomp-
son in his paper to the Society of Arts, on " The Measurement
of Lenses," carrying with it as it does a most important " New
Focometric Method " and a beautiful newly-devised Focometer.

It is not new, of course, for the optician to make exact
measures of optical quantities. Optics involves, as a matter of
course, exact methods ; but as a rule they are both costly and
complicated, and to have relatively easy means of testing with
severe accuracy every part of the microscope associated with its
optical functions will be to accomplish that most desirable of all
things in the interests of many sciences, i.e., make thoroughly
accurate and at the same time low-priced microscopes — as well
as cameras, telescopes, and other optical instruments — accessible
to students.

What is really needed is a uniform system of describing the
properties of a lens. For all that is really placed at the dis-
posal of the student through the accessible sources of informa-
tion, the whole subject might be supposed to be exhausted by
considering the particular case of thin lenses. Prof. Thompson
shows how all the properties of a lens could be indicated by
specifying the position of four points, the two focal points and
the two " Gauss points," where the principal planes of the lens
intersect the action of it ; and by the apparatus he has devised
these latter points can be determined in any lens or combination
of lenses.

There can be but little question that there is need in the in-
terest of English science for more accurate methods and broader
and deeper — as well as special — knowledge on optical matters.

The establishment of an optical laboratory at Kew and else-
where in this country should be fostered by all who are
interested in the production of the highest class optical power
in all directions of scientific research. It is time for this

president's address. 21 3

country to arouse itself to its responsibilities and obligations in
this direction. There are limits beyond which private enter-
prise cannot go. It is to German State aid that we are indebted
for a considerable portion at least of what has resulted to
microscopy by the invention of the Abbe-Schott optical glass,
and it is only societies like this that can know efficiently what
this means.

A well -equipped optical laboratory would, I believe, in-
augurate a new future to theoretical and manipulative optics in
England, and in all probability exert a powerful influence on
the sciences affected by its progress.

The practical microscopist is often struck with the singular
want of knowledge displayed, sometimes in the most unexpected
quarters, in the elements of practical knowledge concerning the
microscope. During the past year those who were not in posses-
sion of more accurate information beforehand might have come
to the conclusion that some sweeping advances had been made
in the very principles of our instrument, for in a leading scientific
journal published in Germany* " a new construction for the
microscope " was very gravely announced. It was by Dr. Lendl,
who pointed out that the supreme purpose of the microscope
having been now accomplished by the construction of immersion
and apochromatic systems of object-glasses, it was time to seek
to combine with this improved power of definition a much in-
creased magnifying power.

And this charming desideratum is, he tells us, to be brought
about quite independently of the objective and without increas-
ing the power of the eye-piece, by what he designates a change
in the construction of the microscope.

The e3^e-piece is removed and replaced by a second complete
microscope, so that the image formed by the objective is no
longer submitted to further amplification by the eye-piece, but
by this auxiliary instrument. By this means it is claimed that
far greater magnification in its proper sense is secured, and far
less light lost than with deeper eye-pieces.

It was soon pointed out by Mr. Nelson, as it had been pointed
out by others, that this was only a more pretentious recurrence
of that optical ignis fatuus of some years ago, the Aplanatic
Searcher.

* "Zeitschr. f. Wiss. Mikr.,'' viii, (1891), pp. 181-90.

214 president's address.

It is a fallacy lying at the root of elementary optics to
suppose that any real increase in the working power of the
microscope can be obtained by subjecting the primal image of
an approximately perfect object-glass to examination by a
second microscope or complex combination of lenses. It has
been tried with blank failure as the result, sufficiently often, one
would have supposed, to have prevented its recurrence now,
when the optics of the microscope have something like a
complete form.

The magnifications, so-called, are of necessity " empty " and
valueless. All they can do is to enlarge the details of the
microscopic image which has been brought about by diffraction
in the first objective, and, therefore, there cannot, by any
possibility, be a single detail added, while the details that the
accurate image does disclose must be blurred and tortured
tenfold more than when subjected to the legitimate action of
well- constructed eye-pieces.

It will never be by means of mere enlargement of the primal
image that progress will be made in increasing the powers of
the microscope. This can only be done by increasing the
capacity of the object-glass to grasjD a larger area of diffraction
fans, so as to enclose within the image all that is produced by
the object ; and to that we must look in the future for the only
legitimate means of penetrating farther into Nature's details.

Another curious error is presented during the year in quite
another way. In a book* by a very respected continental
author, which sets itself the task of making simple to the
uninstructed the entire diffraction theory of microscopic vision
and the practical use of the instrument, there is an inexplicable
misinterpretation, or, at least, misapplication of the very theory
itself.

By all who have mastered the doctrine of diffraction in its
application to microscopic objectives, as enunciated by Abbe,
it is unmistakably understood to be an inference from that
diffraction theory that wide apertures should accompany high
amplification, and that moderate aperture should be the accom-
paniment of moderate and low amplifications. Abbe says that
" a proper economy of aperture is of equal importance with

* " The Microscope." By Dr. Van Heurck. Translatsd b_v Wynne E.
Baxter. Crosby, Lockwood, and Sou, London, 1893.

president's address. 215

economy of power,"* and pointing out that when depth dimen-
sion is needed in observation, the low or moderate powers are
necessary, he then affirms that " no greater aperture should
(therefore) be used than is required for the effectiveness of
these powers — an excess in such a case is a real damage. "t In
truth, it appears almost as an axiom of the diffraction theory of
microscope vision, that we should employ the full aperture
suitable to the power used. That, in short, to over-aperture a
given power in an object-glass is to ruin it.

Curiously enough this appears to be recognized in a broad
sense in one part of the book in question,;]: but in an earlier
page§ the author recommends now what he calls the " American
thread" as distinct from the "society screw" for low-power
objectives, because its larger diameter admits of back lenses to
the objectives of greater diameter, " and thus offers certain
advantages," while it is said that the larger lenses are easier to
make, and the real curvatures are, therefore, approximated
more easily to the calculated curvatures. In other words, we
are recommended noiv to employ for low powers a gauge greater
in diameter than that allowed by the society screw, so as to be
able to employ back lenses of greater diameter.

This, in effect, means that we should give greater apertures
to low powers — apertures, that is, greater than can bo obtained
ivithin the diameter of the society screw.

Now there was a time when these lenses were experimentally
sought, but it was before either oil immersion or apochromatic
days. The matter was first mooted in 1879, and the next year
a screw or gauge was brought out by a Mr. Butterfield, having
a wide diameter, so as to lend itself to a great back lens, and
an absurdly large aperture to low-power object-glasses.

Always desirous of obtaining the advantage of any improve-
ment, and deficient then in the knowledge we now possess, I
induced Messrs. Powell and Lealand to make me a two-thirds
O.G., with as great a back lens as the society screw would
admit. I have that glass now, and its over-apertured condition
is patent.

What then must it be with an enlarged diameter for the

* "Journal R.M.S.," Series ii,, Vol. ii., p. 304.

t Ihid.

X " The Microscope," p. 56.

§ Ihid., p. 49.

216 president's address.

back lens for the same or even a lower power ? Clearly it
traverses the wliole genius and meaning of the diffraction
theory. It was only in pre-apochromatic days that such
attempts as these could be made.

Now, in the new era of objectives, we do not seek for any
purpose to transcend the society screw, and the apertures
easily obtained within the limits of that screw, viz., 0'3 for an
inch and 0*65 for a half-inch objective, represent with high
probability the greatest ratios of apertures to power that will
be produced for many years.

Clearly, then, there must be some egregious oversight in
commending greater back lenses than the society screw will
admit of in the 3'ear 1893, and to an audience receiving instruc-
tion in the paramount value of the diffraction theory of
microscopic vision.

Turning now, however, to work done by means of the
microscope rather than to the instrument itself, a matter of
much interest call^ for our unbiassed hearing.

It has, doubtless, been known for some time to the members
of this Club that Prof. 0. Biitschli has been engaged in efforts
at an experimental imitation of protoplasm. These experiments
are not of an elaborate chemical order, carrying us into the
profounds of organic chemistry. By means of quite another
kind the great problem is approached : the experiments are of
the simplest order, needing only supreme accuracy and care ;
and after ten j^ears of research work we are furnished with the
results.*

Of course it will be remembered that the absolute uniqueness
of protoplasm as the only known seat or centre for the properties
of life has been maintained for the last twenty years by the
leading biologists of the world. Thus Prof. Huxley affirmsf
that the " properties of living matter distinguish it absolutely
from all other kinds of things, and the present state of our
knowledge furnishes us with no link between the living and
the not living."

But it may be fairly affirmed that if, by experimental
methods and careful research, it could be shown that proto-

* " Untersuchnngen ueber Mikroskopische Schaeume and das Proto-
plasma." By O. Butschli. Leipzig, EnglemanD, 1892.
t " Ency. Brit.," Vol. iii., p. 679, 9th ed.

president's address. 217

plasm, endowed with its simplest life-properties, could be
produced meclianically or chemically, or by the co-operation of
both chemistry and physics, there is not a scientific man on the
earth that would hesitate an instant to give it welcome.

Now it would be a travesty to suppose that the great German
biologist even suggests that protoplasm has been made, to say
nothing of protoplasm living. But interesting work has
certainly been done. His work was based on the formation
of foams. When delicate and minute quantities of a substance
that will dissolve in water are mixed with a fatty oil and the
combination is put into water, the water diffuses into the oil
and is deposited in small beads round the soluble substance,
forming what Butschli calls a foam.

Microscopically examined, these particles are relatively large
and coarse. To approximate the German professor's work, we
must place a layer of good olive oil on a shallow glass vessel ;
this must be placed in a constant temperatui'e of oO'^ C.
Gradually the oil attains a suitable degree of thickness and
viscosity. This is a crucial matter, and only several tests
can determine it.

From this, when in the right condition, vesiculate drops are
prepared. A little dry carbonate of potash is ground with
great care in a small agate mortar. This is breathed upon
until the salt becomes slightly moist, and then a drop of the
•oil is added ; the two constituents are then' mixed until they
become a thick paste. A few drops, extremely minute, taken
from this are placed on a thin cover-glass, which has previously
had four equally thick pegs of paraffin slightly melted upon it
to form legs or supports. A small drop of water is now placed
on the centre of a slip of glass, and the cover-glass, with its
drops of paste, is laid on so that the paste makes contact wath
the water. This is placed in a damp chamber for twenty-four
or thirty hours, ^vhen the whole appears milk-like and opaque.

The preparation must now be well-washed with water. I
find that this can best be done by means of a vaccine-tube of
water supplied to one edge, and drawn out by blotting paper,
or a small bundle of fine glass-blown fibres tightly bound
together on the other side.

If the drops are now carefully examined, it is highly probable
that they will be seen to change both their positions and their

218 president's address.

shapes. If, however, a pressure be used, or still better, a
mixture of equal parts of glycerine and water be diffused
through it, a strong streaming movement will be seen ; but, in
my experience, in repeating the experiments, only when on a
warm stage of 50° C, and I find that amoeboid movements
rarely are seen except under pressure.

It thus appears that we are dealing with a very fine froth,
consisting of a laige number of minute beads of soap dissolved
in water, and each enveloped by a thin wall of fluid oil. All
such films, when in contact, unite in many-sided figures, as on
the surface of the fluid from which a child is blowing bubbles,
or with which the work of the laundry is done.

The minuteness of the space between the glass-surfaces
causes this mesh-work, so-formed, to take the appearance of a
complex cellular tissue, and there are thickenings which take
place in the cellular mesh which certainly have a granular ap-
pearance ; but, I may add, that no appearance in the colloid mesh,
whether granular or fibre-like or folded, appeared other than as
the result of minute hollow beads when sufficiently examined.

There may be an interior relatively large vacuole, and a
cellular border with its walls more or less radially arranged,
and the whole may flow, retaining all its features. In the
drops also there are relatively powerful streaming movements
within, reminding us of streaming in both vegetable and
animal cells. These are best seen when the glycerine has
done its work upon the foam.

It is, of course, explained that these internal movements
depend on surface tensions. The surface tension between the
oil and the solution of soap is not so great as that between the
oil and the water ; this ultimately accounts for the streaming
movements.

From this it is argued that we have, only in a simpler form,
the extremely complex chemical conditions, and active altera-
tions of state constantly arising in protoplasm. It is contended
that altered tensions within and outside the cell constantly
arise, hence, mechanically at least, arise streaming, alteration
of place, and mutation of form.

That all this is extremely ingenious and profoundly interest-
ing no one competent to judge will deny, and the repetition of
the experiments is fraught with pleasure and deep instruction.
But it would be a grave error to suppose that by any of these

president's address. 219

experiments we have come any nearer to the making of actual
protoplasm.

The imitation of streamings and amoeboid changes and rapid
movements of position are all physically explicable, and no
matter hoAv apparently complex the thickened portions of the
united froth bubbles may apj)ear, they are, by sufficient magni-
fication, resolvable into minuter bubbles. But he must have
lenses such as I have never yet been able to touch, or must
have a secret in the use of them which I do not know, who can
resolve the strange, the at present undefinable, reticulation,
radiate, or plexus-like structure of protoplasm into bubbles.

I have examiued all the movements of these artificial foams
with care and patience, and after years of observation on pro-
toplasmic movement, I find that they differ much and in many
ways from the movements seen in living matter. The co-
existence of streams in opposite directions is not uncommon in
living cells ; every observer, indeed, will have noted an occa-
sional sudden reversal of cellular streams, and not unusually
the cessation of the stream and its subsequent recommence-
ment. But more than this, the stimulating action of oxygen
or electric energy is at once manifest on the living matter, but
they are practically inert on foams.

That approximate physical explanations of certain initial
movements of living matter, as in white corpuscles, pus-
corpuscles, amoebee, and so forth may have been discovered by
ingenuity and effort, by no means proves that the same results
are brought about in the same way in living protoplasm, nor
do they prove that we are, as yet, any nearer the discovery of
the ultimate structure of protoplasm itself.

We are grateful for the light given and the amount of truth
disclosed, but a streaming froth and streaming living proto-
plasm are immeasurably far apart.

When the higher complex chemical nature of protoplasm is
considered, side by side with the totally different conditions
under which a compound, capable also of being made in the
laboratory, is made by living matter, we have surely a strong
reason for considering that vital chemistry is at least unique,
and that it will not inevitably follow that because delicately
made and carefully observed foams simulate the internal and
external movements of protoplasm in its simplest form, that,
therefore, the phenomena of life are the less difficult to explain.

220 president's address.

We must first unravel the mystery of protoplasmic structure
before we can venture to claim tliat we have found an analogue
to the simplest movement it exhibits.

I need hardly say that irritability, power of nutrition, and
cyclic changes, with power to multiply its kind — the essential
features of the simplest living cell of protoplasm — are not even
suggested as properties of these most interesting foams.

A subject that must command, from a society like this, quite
as large an interest as the above, is the demonstration now
held to be completely established that it is to bacterias — pecies
of " micro-organisms " — that some of the most obscure and
important phenomena in agriculture are due.

In the early part of 1891 M. Pasteur published some most
interesting results obtained by Herr Winogradsky by experi-
menting with soil taken from all quarters of the world,*
enabling him to conclude that two organisms are emjDloyed in
the nitrification of the soil, by which plants obtain their nitro-
gen. He had previously shown f that the nitrifying process
was effected by a single species of bacteria which was called
Nitromonas, but later he satisfied himself that there are
important morphological differences in these organisms, and
they were classed in a group of nitro-bacteria, the common
characteristic of which is the oxidation of ammoniacal nitrogen.
He now concludes that two organisms are employed in natural
nitrification, one forming nitrite and the other nitrate, and con-
sequently the process is completed in two periods. Both these
organisms he succeeded in isolating, the nitrate-former, whicb
is oval, about 0"5 of a micron long, and about two times less in
breadth ; the nitrite-forming organisms are oval or globular
and about double the size of those which form nitrates.

In normal earth, nitrate only is formed, the production of
nitrous acid being a transitory phenomenon, and, even in the
presence of considerable quantities of ammonia, being oxidized
as soon as formed. The nitrite ferment, either under natural
or under artificial conditions, can only form nitrite, and nitrous
acid thus formed remains as such in the ground if the 7iitrate-
former be absent.

If the nitrate ferment as well as the nitrite, however, be
added the process is completed in the ordinary way, only the

* " Annalps de I'Institut Pastear," 1891, p. 577.
t Ibid,, \). ^2.

president's address. 221

merest traces of nitrous acid appearing. It is interesting to
know that the discovery and isolation of the former of these
two organisms thns discovered had been, with much care and
by long effort, isolated, identified, and published a month before
Winogradsky's earlier paper appeared, by Professor Percy F.
Frankland, F.R.S., and he has pointed out the full details of
the subject.*

It has long been admitted that one of the most essential
sources of nutrition found by plants in the soil is nitric acid.
The agriculturist could grow no crops without this, however
otherwise complete the soils might be.

Still it is found on analysis to be most minutely present even
in ordinary fertile soils. This arises from its eager consump-
tion, when present, by plants, and its being washed out by
rains. But the soil under ordinary circumstances constantly
generates nitric acid from the many nitrogenous manures placed
upon it, and it is in the form of nitric acid that the nitrogen of
manures obtains access to plants. This was proved sixteen
years ago by showing that the nitrifying process — the produc-
tion of nitric acid in the soil — is stopped by all those materials
known as antiseptics, as well as by heat and other agencies
inimical to life.

Later it was shown that the process of nitrification could
take place in solutions destitute of organic matter.

In 1886 Professor Frankland and Mrs. Frankland employed
this method, in order, if possible, to isolate this special organism,
and they carried on a process of nitrification over a period of
more than four years, without the organism itself being sup-
plied with any organic food. But they succeeded, as Winograd-
sky did, in separating a nitrifying organism, but only one
which had the property of converting ammonia into nitrous and
not into nitric acid.

Of course the change from ammonia into nitrous acid is as a
result in organic chemistry much more difficult to accomplish
than the change from nitrous acid into nitric acid. So then
the vital process of oxidation must be quite distinct from that
effected by purely chemical agents.

In the later researches of Winogradsky, to which we have

* Friday evening discourse at the Royal Institution, February 19th,
1892, •' Nature," Vol. xlvi, p. 135, et seq.

JouRN. Q. M. C, Series II., No. 32. 16

222 president's address.

referred, he succeded, as we saw, in isolating a micro-organism
which only possesses the power of converting nitrous acid into
nitric acid ; it cannot attack ammonia and convert it into
nitrous acid. The former may be called the nitric ferment,
and the nitrification of the soil with its aid is clear. It is
brought about by two independent organisms, the first pro-
ducing nitrous and the second nitric acid.

The scanty presence of nitric acid in the soil does not, how-
ever, prevent Professor F. Frankland from suggesting that the
immense deposits of nitrate of soda in the rainless districts of
Chili and Peru are the result of " a gigantic nitrification pro-
cess at some previous period of the earth's history," and that
"the nitrifying organisms then and there" must have been
endowed with " very much greater powers than they possess to-
day." Moreover, the nitrifying organisms now found can build
up living protoplasm in a solution from which organic matter
has been rigorously excluded; and, therefore, can only have
been elaborated by carbonic acid as the source of protoplasmic
carbon, and from ammonia, and nitrous or nitric acids as the
source of protoplasmic nitrogen — and if this be accurate and
is subsequently confirmed it represents a new phase in our
knowledge of the functions of plants without chlorophyll.

In the same way there is an excess of nitrogen in leguminous
crops which cannot be accounted for by the combined nitrogen
supplied to the land in the shape of manures and in rain
water ; but it has been shown that this excess of nitrogen is
largely dependent on the presence of certain bacteria flourish-
ing in and around the roots of these peas, beans, vetches and
their like, and these tuberosities are found, not only to be rich
in nitrogen, but to harbour swarms of bacteria.

We have long been accustomed to think of bacteria as active
agents in putrefaction, and the various ferments ; to be the
virus of many and terrible diseases in man and animals. Nay,
they infest the water we drink, the food we may eat, even the
tobacco we smoke, the butter of our breakfast tables, and the
very air we may breathe ; but it is a comparatively new role
for their activity that the essential processes of vegetable
physiology are brought about by their agency, redeeming to
some extent the adverse influences they so generally exert.

223

Note on Wenham's Method for obtaining an Oblique View of
A Microscopic Object and on Marshall's Zoophyte Trough.

By J. E. Ingpen, F.R.M.S.

(Read June 17th, 1892.)

Mr. Ingpen made some remarks with reference to his exhibit
of Diatoms and Lepisma scales, shown by Mr. Wenham's method
of obtaining oblique vision of surface markings. For this pur-
pose a slip of glass about ^-^ of an inch wide was ground and
polished at one end to an angle. The objects were scraped up
with the knife-edge, and another similar slip pressed against it
to recompose or neutralize the colour, the light thus entering
and issuing at right angles to the slip. The angle for dry
lenses must be less than 40"", about 35^ being suitable ; for bal-
samed objects 45° would be preferable.

The objective, if of large aperture, must be adjusted for each
thickness of the upper prismatic edge, according to the position
of the object.

The Diatoms shown were immersed in cedar oil ; the Lepisma
scales were dry.

The original paper will be found in the " Monthly Micro-
scopical Journal," Vol. xiii. (1875), p. 156.

Mr. Ingpen regretted that so valuable a method of observa-
tion should have been so little employed. He himself only re-
membered it somewhat recently upon ct)ming across some of the
prisms he had purchased in 1875. Independently of its assist-
ance in the solution of problems of insect-scale structure, etc.,
its use in determining the real forms of diatoms and other
organisms, by viewing them in an oblique direction, was of
importance. Messrs. Ross and Co. had not now any of the
prisms on sale, but there would be no difficulty in getting them
made, if there were any demand for them, as Mr. Wenham had
given full directions for their construction.

Mr. Ingpen also exhibited and described a zoophyte trough

224 NOTE BY J. B. INGPEN.

and open cell which had been introduced by Mr. W. P. Mar-
shall so long ago as 1869, and which he thought, like the
apparatus just described, had fallen into unmerited disuse. It
was simply a cell, of any required dimensions, cemented to a
glass slip, and only half coyered with thin glass. When inclined
it could be used as a zoophyte trough ; when laid flat half of it
was an open cell, the wall around it preventing the escape of
objects or fluid, so that dissections could be made or objects
arranged and returned into the covered half for examination.
Mr. Marshall's paper is reprinted in the " Monthly Microsco-
pical Journal," Vol. i. (1869), p. 239.

In answer to a question, Mr. Ingpen said that he had no
difficulty in cleaning the troughs with a curved stick or wire,
or a long camel's-hair pencil, or, for the shallower cells, a piece
of folded paper, wetted with water or alcohol.

225

Note on a New Spherometer.
By E. M. Nelson, F.R.M.S.

(Read October 2\st, 1892J

This spherometer made by Mr. Curties from my design
differs from others because the lens to be measured is placed
on it, instead of the spherometer being placed on the lens.

The usual three points are dispensed with, a ring being sub-
stituted, which is cheaper to make as well as more accurate.

The ring, which is held in a tripod stand, has, passing upw^ards
through its centre, a micrometer screw having fifty threads to
the inch, and the usual drum-head reading to — ^ — inch.

To use the instrument the drum-head is first brought to
zero by means of adjusting screws and a glass " plane surface."
The lens is then substituted for the " plane surface," and when
the hemispherical polished steel head of the micrometer screw
is just brought into contact with the lens the reading is taken.

There are three rings of different diameters to suit lenses of
various sizes.

The reading of the drum-head shows the length of the versed
Sine V, from which, when the chord C is known, the value of R,
the radius, may be found by the following formula : —

2 V
By making C a root, the computation becomes one of mere
inspection, as can be taken out of a table of reciprocals.

Thus if C ■= /"8" = 2-82843 inch,

2 V.
When C = / 2~= 1-41421 inch,

And if C= v^ - 2 = -447214 inch,

R=_L/ 20v+-L^
40 V v/

These are the diameters of the three rings in the instrument

before 'you.

226

Extract of a Letter from Dr. V. Gunson Thorpe, R.N., China
Station, Dated 19th Sept., 1892.

(Read hy Mr. G. Western, November 18th, 1892.)

Doubtless yoiT will be glad to hear from an old friend, and
of the progress of Rotiferous research in this far-off Empire.
My ship is lying at Wuhu, a Chinese city on the banks of the
magnificent Yangstze Kiang river, 26 miles from its mouth.
China is simply a paradise for the microscopist, and the life in
its fresh waters has, I believe, been wholly untouched. Stand-
ing at a given point anywhere on the plains of China one is
surrounded on all hands by scores of ponds, in which grow the
splendid Lotus Lily. The fields are intersected by dykes for
irrigation purposes in all directions. Here, if anywhere, the
links connecting the different species and genera will be found,
and some, if not many, of the existing genera will have to be
materially altered to admit the new Chinese fauna. I am
flattering myself that my next paper will cause somewhat of a
sensation amongst our community of Rotifer hunters. To
enumerate some of the new discoveries in China I have found
a magnificent Melicertan, with eight lobes to its corona, and
for which, of course, a new genus will have to be created. I
have found in the rice fields of Wuhu a new species of Trochos-
phsera, in which the globe is unequally divided by the ciliary
wreath. Also a Rotifer with a corona not unlike Lacinularia
socialiSi but with four bullae round its neck like Megalotrocha
alhqflavicans. A Rotifer has been found with a corona distinctly
that of Megalotrocha, but with no bullae round the neck. It
constructs for itself also a mucous tube — a Megalotrocha or
Lacinularia (I have not quite decided which), the ventral
surface of which is covered with prickly spines. Also a new
Notops. Megalotrocha semibullata swarms in nearly all the
ponds here. Now I have to confess an error. I have found
once again Bhinops (?) orbiculodiscus. It possesses a deeply-set
dark crimson eye. How on earth I came to overlook it when I

A LETTER FROM DR. V. GUNSON THORPE. 227

foand this Rotifer in Ireland I cannot conceive. Of course it is
not a Rhinops, and as far as I can see at present it ought to be
placed in a genus by itself. The only excuse for my error is
that at first I did not possess an Abbe condenser, which I do
now, and which, of course, makes everything more distinct
under high powers. The Rotifer is a very small one dro" ^^
length). Some of the clusters of the Chinese Lacinularia and
Megalotrocha are simply enormous, quite a quarter of an inch
across, hanging like white bits of wool from the stems of the
water plants. I should say thac some consisted of quite 200
individuals. I think the time is not far distant when some-
thing will have to be done with these two genera ; probably
one of them will have to be done away with, and the two
amalgamated. If you care to make any use of this letter at the
Quekett Club you are quite at liberty to do so. ... I always
look back with pleasure to the evening I spent at the Club,
where I met so many interested in the same pursuit. . . . The
Journal which reaches me regularly gives me a good deal of
information of your excursions. I wish I could join you. . . .

228

An Improved Form of Dr. Edinger's Projecting Apparatus.
By E. M. Nelson, F.R.M.S.

(Read November \Uh, 1892.J

This instrument, which has been made for me by Mr. Curties,
is similar to that suggested by Dr. Edinger in the " R M.S.
Journal," 1891, p. 812. I have, however, made one or two
trifling alterations, by which an increase in the illumination of
the image is secured, which adds to its efficiency. It consists of
an upright brass rod* holding a short horizontal tube, at the
end of which a mirror is placed at an angle of 45°. Below this,
for a condenser, is fitted one of my aplanatic bull's-eyes, the
elements of which can be used either singly or together as
occasion requires. The stage, which is also horizontal, is
placed below the condenser, and is fixed to a separate piece,
which carries also the projection lens with its rack work.
This arrangement permits both the stage and projecting lens
to be together moved from the condenser, while the projecting
lens has an independent movement to and from the stage. A
wheel of diaphragms is placed above the stage. The source of
illumination should also have an aplanatic bull's-eye, and should
be one foot distant from the condenser.

This instrument not only shows low power objects very
e;ffectively, but also is most nseful for drawing them. As the
image is inverted and transposed the drawing will be precisely
like the original.

* The brass rod has since been altered to a wooden board.

229

N'OTE ON THE CONSTRUCTION OP THE LORICA IN THE GeNUS

Brachionus.

By Surgeon V. Gunson Thorpe, R.N., F.R.M.S.
(H.M.S. "Peacock," China).

After careful examination of many of the known species of
Brachioni, as well as many new species and varieties found in
tropical countries, I have come to the conclusion that the so-
called dorsal surface of the lorica in reality consists of two
plates, instead of the one antero-posteriorly curved plate as
generally received. This doctrine, it seems to me, has been
strengthened by many new discoveries since the valuable
monograph on the "Rotifera" was first issued. My proposition,
therefore, is this, that the lorica of a Brachionas be in future
described as consisting of a ventral, a dorsal, and a hasal plate,
the latter two constituting what is now known as the dorsal
surface. I consider that I am supported in this view by the
following considerations : The so-called dorsal surface of the
lorica in B. ruhens (Fig. 1), B. urceolaris, and other species is
divided in the majority of individuals by a very sharp line of
demarcation at the junction of the upper two-thirds wdth the
lower one- third, where the lorica curves to join the ventral
surface posteriorly. No doubt there are cases in which the
division of the dorsal surface into a dorsal and basal plate is not
so well defined (Fig. 3), but I think that these cases are in a
minority. In B. militaris (Fig. 2) and also in B. quadrahis one
sees the basal plate extremely well defined. But the argu-
ment is still further strengthened by the fact that I had the
good fortune to discover in 1890, at the Cape of Good Hope, a
Brachionus {B. ftirculatus), in which the dorsal plate was pro-
longed posteriorly (Fig. 6) so as to form a wedge-shaped space
between the lower portion of the dorsal plate and the basal
plate, in which space parasitic infusoria took up their abode.*
Since then I have come across in Ceylon and China transitional

* " Journ. R. Micros. Soc.," 1891, p. 302.

230

V. G. THORPE ON THE LORIGA IN THE GENUS BRACHIONUS.

stages of this construction. In a Brachionus (Fig. 5) found in
Colombo the dorsal plate was distinctly ^^rolonged, but only to
the very slightest extent, whilst the basal plate was well
defined, evidently the first stage in the production of a distinct
species. Such a prolongation of the dorsal plate, concurrently
with the existence of a basal plate, would obviously be impos-
sible, unless each were separately developed.

I venture to send this note on the subject in the hope that by
discussion, and more especially by a careful examination of
varieties, a solution to a puzzling problem may be attained.
In addition to sketches, 1 beg also to forward a rough paper
model of the lorica of a Brachionus found in China, Australia,
and Ceylon as a typical specimen.

V. G. Thorpe, det

Explanation op Plate.

D. Dorsal plate. B. Basal plate. Y. Ventral plate.

Fig. 1. — Dorsal surface of Brachionus ruhens, showing the
division into dorsal and basal plates.
, 2. — Side view of Brachionus militaris.

V. G. THORPE ON THP] LORICA IN THE GENUS BRACHIONUS. 231

Figs. 3, 4, 5, and 6. — Diagrammatic longitudinal antero-pos-
terior sections of : —

Fig. 3. — B. rubens ; line of demarcation between dorsal and
basal plates ill-defined.
„ 4. — B. rubens; line of demarcation between dorsal and

basal plates well-defined.
,, 5. — A species of BracMonus found in Ceylon, with com-
mencing prolongation of dorsal plate.

„ 6. — BracMonus furculatus from South Africa; the dorsal
plate greatly prolonged.

232

Fraunhofer Applies his own Diffraction Theorem to the
Microscope.

A Note by Edward M. Nelson, F.R.M.S.

The following very important quotation with regard to the
above subject will be found in the article "Light," by Sir John
Herschel, Bart., in " The Encyclopaedia Metropolitana " (1845),
Vol. ii. (Mixed Sciences), p. 490, art. 758 :—

After a description of the means employed by Fraunhofer to
measure the angular divergence of diffraction spectra, there
follows a discussion of his well-known law, derived from those
measurements, where it is shown that, when the elements of
which a grating is composed are at a distance less than one
wave length from one another, sin 6 becomes greater than
unity, an impossible quantity, so that when the medium is air
and the pencil is direct, i.e., perpendicular to the plane of the
grating, no spectrum can be given off.

Sir John Herschel then says : " Mr. Fraunhofer seems
inclined to conclude further, that an object of less linear
magnitude than X can, in consequence, never be discerned by
microscopes as consisting of parts, a conclusion which would
put a natural limit to the magnifying power of microscopes,
but which we cannot regard as following from the premises."

From this passage I judge that Fraunhofer had discovered
that the admission of spectra of the first order within the
aperture of a microscope was essential for the visibility of
resolvable detail.

233

h\ ifHemoiiam^

HENRY F. HAILES,

BoKN September 13th, 1827: Died October 21st, 1892.

Since the issue of the last miniber of the Journal of the Club,
we have lost, by death, the services of our esteemed Editor and
Honorary Foreign Correspondent, and it would not be fitting
that this, the first number issued since his death, should reach
the hands of the members of the Club without containing some
tribute to his worth. It would have been extremely easy to
find a member of the Club much better fitted than myself to
write such a tribute, but it would be difficult to find one who
entertained a warmer regard for Mr. Hailes, or who was under
greater obligations to him .

Henry F. Hailes was born at Camden Town on the 13th
September, 1827. His father does not seem to have taken a
great deal of trouble either about his education or about giving
him a start in any business. Most of the large store of know-
ledge, upon many subjects, that he possessed, seems to have
been acquired here and there and by following the bent of his
own inclinations. His oldest friend was a Mr. William Croft,
and, as the story of the way in which their acquaintance was
formed reveals somewhat of Mr. Hailes' character and pursuits
at the time, I may be pardoned for telling it here. Croft and
Hailes, both boys, lived near together in Camden Town. One
day the former laid a train of gunpowder upon a garden wall,
and was about to fire it, when Hailes came up on the opposite
side of the wall and blew the gunpowder away. Croft jumped
over the wall, and, although much the smaller boy, commenced
to belabour Hailes, when the latter, who was very fond of
experimental chemistry, said, " Don't let us fight, and I will
tell you how to make gunpowder." This he did, greatly to the
delight of the younger boy. The two became fast friends from
that day and continued to be so up to the time of Hailes' death.

234 IN MEMORIAM.

Mr Croft, in telling the story, adds that the reason Hailes gave
for not defer ding himself was, that he was always afraid to
strike a boy smaller than himself lest he might injure him.

Mr. Hailes' first entry upon a settled occupation seems to
have been made when he went to Collard's as a substitute for
this same Mr. Croft to complete his apprenticeship, Mr. Croft's
health having broken down and his finding a substitute being
the condition of his release. Here he acquired that skill in the
use of tools and that liking for mechanical work which not
only helped him immensely in the business he subsequently
followed, but was to him a never-ending source of pleasure and
profit at home. Many a time have I, too, profited by this
mechanical skill, both by receiving advice and instruction upon
work I have myself had in hand and by getting parts of it
which were beyond my skill done for me. Fond, however, as
he was of mechanical work, I don't think my friend was
altogether happy at Collard's. He, however, made the
acquaintance of a Mr. Basire, who gave him some lessons in
mechanical drawing, and Hailes and his friend Croft (who was
then in Collard's tuning department) diligently worked at this
subject together. When he had acquired a good deal of skill
in this way, Hailes, then about twenty-five years old, answered
an advertisement for a draughtsman in Messrs. Newton's office
in Chancery Lane. He obtained this appointment, gave up the
pianoforte making, and remained with Messrs. Newton down
to the time of his death.

Mr. Hailes was one of the eleven men who attended the first
meeting of the Clab at Piccadilly on the 14th June, 1865. Of
these original members only three now remain upon the Club
list, namely, Mr. W. M. By water. Dr. M. C. Cooke, and Mr.
Edward Jacques. Some of the others are still living, but do
not retain their membership of the Club. During the twenty-
seven years of the Club's existence Mr. Hailes held some office
in the Club in every year except the first, on many occasions
fielding two offices at once. He has been Vice-President
(twice), Member of Committee, Member of Exchange of
Slides Committee, Curator, Honorary Secretary (with Mr.
Ingpen), Honorary Secretary for Foreign Correspondence, and
for the last nine years (while still filling the latter office) has
ably edited the Club's Journal. In the first year of the Club's
existence his name appears among the donors of slides, and he

IN MEMORIAM. 235

has given many others at intervals since that time. He
designed the lamp shade which, in a modified form, is still in
use upon microscope lamps, and, in 1877, designed and brought
before the Club a very useful machine for cutting both hard
and soft sections. Although interested in every branch of
microscopy, and possessing more or less knowledge upon every
branch, he had devoted himself for many years almost entirely
to the study of the Foraminifera, and of beautifully mounted
slides of these, as well as of foraminiferous material, he
possessed a large and valuable collection.

Until attacked with the disease which caused his death he
does not seem ever to have had any very serious illness, at any
rate after his marriage. He had, however, for years suffered
intensely, and at somewhat frequent intervals, from hemicrania,
and was often quite prostrated by the violence of these attacks
of headache. On Saturday, the 15th October last, he returned
home from the City apparently in his usual health. A window
had been broken at the back of the house in which he lived,
and Hailes, who liked, as far as possible, to do all the work
about his home for which most people employ the British
artisan, set to work to repair the damage. A cold north-east
wind was blowing, and the job occupied rather longer than
usual because of his breaking one pane of glass and having to
get another. It was, doubtless, while doing this that he caught
the chill which caused his death. On Sunday he did not go
out all day, feeling less well than usual, and being troubled
with toothache ; but on Monday he felt better and got up to go
to business as usual. Before starting, however, he had a
violent fit of shivering and returned to bed. On Tuesday he
again got up ; but the doctor, who was then called in, sent him
again to bed. An examination showed that he was suffering
from a sharp attack of pleurisy and pneumonia, and that his
heart was also weak ; at that time, however, the doctor hoped
to be able to save his life. On Wednesday he was much worse,
and on Thursday afternoon he evidently felt that his end was
near. He then took leave of all his family, being quite con-
scious, and speaking to each one individually. In the evening
he rallied a little, though breathing was extremely difficult,
and the heart was not only weak, but had become displaced by
his starting up in bed. During the night, however, he became
weaker until, just before eight on Friday morning, he passed

236 IN MEMORIAM.

away. Although wandering in his mind occasionally, he was
conscious and sensible at intervals to within half-an-hour of his
death, and, even when his disease had made great progress, was
still anxious about his duties in connection with the next issue
of the Club Journal. He was buried at I^ew Southgate
Cemetery on the 25th October, in the grave in which his
mother had been laid only about a year and nine months before.
From no one of its members has the Club received services
as varied and continuous as from Mr. Hailes, and no member
of the Club has ever been more ready to place his knowledge
at the service of beginners in microscopy than he. I, like
many others, received my first start with the microscope as
well as much subsequent help and guidance at his hands. In
connection with " The Crouch End Scientific Society " he
started a class of instruction for beginners in microscopic work,
and this was only abandoned when it became evident that its
members lacked either the time or the inclination to apply
themselves seriously to the business in hand. Nothing but
dire necessity ever kej^t him away from the meetings of the
Club, and it will be long before members will cease to miss his
presence and help. His abundant knowledge upon all those
matters which belong to what one may call the practical side
of life, was always at the disposal of the Club or of any of its
members who needed it ; and he was constantly telling one
where to buy this, and another how to do that. He was of a
very modest and retiring disposition, full of quiet humour, and
possessed the most even temper of any man of my acquaint-
ance. Whether at home or abroad, ill or well, busy or at
leisure, he was always the same, always ready to be of service,
always pleasant and agreeable. To the business of the Club
he was most devoted, and, fond as he was of cycling in a quiet
way, he could not be persuaded to indulge in a ride until all
demands of this nature had been met. With him I have
visited most of the prettiest spots in North Middlesex, South
Essex, and South Herts, and his keen appreciation of their
beauties added much to the enjoyment of these visits. When
they are repeated the pleasure will be greatly diminished by
being unshared. Our friend's place is emptj^ and will be
difficult to fill.

Charles Emery.

237

PROCEEDINGS,

June 3rd, 1892. — Conversational Meeting.

The following objects were exhibited : —

LopJiopus ...

Diatoms from Guatemala

Teeth of Leech, Hirudo medicinalis

Asplanchna BrightiuelUi ...

Ahies grandis, Trans, and Long. Sec.

Crystalloids of undescribed Tunicated ^

Ascidian, from Australia, unique [ Mr. B. W. Priest.

specimen ... ... ... J

Mr. F. W. Andrew.
Mr. A. Ashe.
Mr. E. T. Browne.
Mr. W. Burton.
Mr. G. E. Mainland.

June 17th, 1892. — Ordinary Meeting.
Dr. W. H. Dallinger, F.R.S., President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following members were balloted for and duly elected
members of the Club : — Messrs. Charles Bates, Ernest Benest,
Geo. Chaloner, F.C.S., Thomas Davies, L.R.C.P.Ed., M.R.C.S.,
Daniel Finlayson, Arthur B. Hoskings, A.M.Inst.C.E., F. R.
Dixon Nuttell, Edward B. Pressland, and Charles Turner.

The names of four candidates were read and suspended until
the next meeting.

The additions to the library were announced.

The Secretary said he should like to direct the attention of
members to some little books published by M. Paul Dupont, 4,
Rue de Bouloi, Paris. They were pocket floras, and three had
been issued up to the present. 1. " A General Flora of the
Paris District ; " 2. " Flore des Champignons ; " and 3. " Flore
des Mousses." The two latter, he thought, would be found
yery useful. There was a general introduction, and a complete

JouRN. Q. M. C, Series XL, No. 32. 16

288

diagnosis of the genera and species, illustrated by very numerous
tiny, but exceedingly clear figures. The printing also was most
beautifully done. These books could be obtained at Messrs.
Dulau's, Soho Square, and were quite inexpensive — five or
six francs — and easy to read. Other volumes were to follow.

Mr. H. W. King read a paper on Monstera deliciosa, a
climbing plant of the genus Aracese, order Spadiciflor^, possess-
ino- some peculiarities of structure, of microscopical interest.
The paper was illustrated by well-executed coloured diagrams.

The President said Mr. King's communication was of con-
siderable value, and had evidently been very carefully worked
out ; but from the great detail in which the interesting points
had been examined, some amount of study was necessary to
quite follow it out, which they would be able to do when
printed in the journal, and he was sure those who had listened
with attention to Mr. King's paper would desire to pass him a
very cordial vote of thanks for it, which was done.

Mr. Ingpen read a note on Mr. Wenham's method of obtaining
oblique illumination of structures, such as scales and diatoms,
under high power. This was brought out as long ago as 1875,
and by reminding the members of it, perhaps some of them
would further experiment with it. The simple apparatus was
exhibited, and its use explained by a drawing on the board. Mr.
Ingpen said there was another small appliance, which, he
thought, had undeservedly fallen out of use, viz., Marshall's
zoophyte trough or life-cell. It was made by fixing any sized
circular cell to a slip, and cementing over one-half of this cell a
semi-circular piece of thin glass, thus it could be used as an
ordinary trough when inclined, or an open cell when lying flat.

A Member thought perhaps it had been neglected from the
difficulty there might be in cleaning the covered in part ; but
Mr. Ingpen said it was quite easy to clean under the thin glass
by a camel-hair brush or strip of blotting paper.

A vote of thanks was passed to Mr. Ingpen.
The President reminded members that this was the last
meeting of the session, and he wished them all a pleasant
vacation, with the hope that it would be spent in providing
material for discussion on future occasions.

The usual announcements were then made, and the proceed-
ings terminated.

239

The following objects were exhibited : —

Plumatella . . . ... ... ... ... Mr. F. W. Andrew.

Noteus quadricornis ... ... ... Mr. W. Burton.

Diatoms shown with Wenham's ")

oblique vision method ... ) ... ngpen.

Notops ruber, Hood, n. sp. ... ... Mr. C. J. Machin.

A new coloured Rotifer was exhibited by Mr. G. Western.

July 1st, 1892. — Conversational Meeting.

The following objects were exhibited : —

Madreporic Plate of Asterias rubens ... Mr. E. T. Browne.
Hydalina senta ... ... ... ... Mr. W. Burton.

Notops ruber ... ... ... ... Mr. C . Rousselet.

July 15th, 1892.

The following objects were exhibited : —

Draparnaldia glomerata ... ... ... Mr. F. W. Andrew.

Stephanoceros EicJiornii ... ... ... Mr. W. Burton.

Section of some Calamarian Fruits ]

from Lower Coal Measures of I Prof. Williamson.

Lancashire and Yorkshire ... I

August 5th, 1892. — Conversational Meeting.
The following objects were exhibited : —
Megalotrocha albo flavians ... ... Mr. F. W. Andrew.

Marrow-bone Starch Grains oi Euphorbia ")

f Mr. H. Morland.

September 16th, 1892. — Ordinary Meeting.
Dr. W. H. Dallinger, F.R.S., President, in the Chair.

The minutes of the meeting of June 17th were read and con-
firmed.

The following gentlemen were balloted for and duly elected
members of the Club :— Mr. F. W. Eyre, Mr. W. H. Hardy,
Mr. Stanley von Losecke, and Mr. H. S. Martin,

240

The following were proposed for membersliip : — Mr. J.
Luscombe Luscombe and Mr. Thomas W. Hinds.

The following donations were announced : —
"Proceedings of the Geologists") j,^^^ ^j^^ Association.

Association" ... ... ...J

"American Monthly Microscopical "I Fd'f

Journal " (two numbers) ... . . . j

"The Botanical Gazette" (twoj in Exchange.

numbers) ... ... ... ...}

" Proceedings of the Belgian Microscopical Society."

" The Microscope " (two numbers)

" The Essex Naturalist " (two numbers)

The thanks of the Club were voted to the donors.

The President said that the agenda that evening did not
present any plethora of matter, very few communications having
yet been received, many members being, no doubt, still absent
on their holidays.

Mr. David Bryce read a paper " On a new species of Adinetae,"
from Moss.

The President, in proposing the thanks of the Club to the
author, said he was sure the subject was one which would prove
of great interest not only to the members of the Society, but to
all who had made the Botifera their study.

Mr. J. E. Ingpen wished to call attention to a note which
was printed in the last number of the Journal as to one of the
high refractive media for diatom, mounting. It was a variation
made by Father Thompson on Professor Hamilton Smith's
medium. It was first made some years ago, but the formula
was not at the time disclosed, but after some little persuasion
it had been communicated, and was published, as mentioned,
but (to save time) without having previously been before them
at a meeting. He therefore referred to it in order that it might
appear on their minutes. From experience it certainly seemed
to have stood remarkably well though its refractive index was
so high, and he thought they were to be congratulated in being
now in the possession of as fine a mounting medium as anything
which Professor Hamilton Smith had himself made.

Mr. H. W. King read a paper entitled " Brief observations
on Pond Life from the West Indies," the subject being illustrated
by diagrams.

241

The President said they had in this paper an instance of how
much was sometimes to be gained by observations in even the
most unlikely quarters, for it might well have been supposed
that water of that kind after travelling so far would not be
likely to furnish much of any interest.

Mr. Western said thit the subject had particularly interested
him because he had repeatedly found Bdelloid Rotifers living in
tubes which they had built for themselves. He could not
account for this habit because they were not breeding, and he
had found quite as many free swimming as tube building, but
no eggs or embryos. He had found tubes built by Rotifer
marcrurus, and also by Botifer vulgaris.

Mr. Bryce said that it was recorded by Gosse that Furcularia
forficula was sometimes found living in tubes, and he thought
there was also a record as to Rotifer vulgaris in the " Q.M.C.
Journal." He rather inclined to the idea that the case was
more an aggregation of odd atoms than one regularly designed
and constructed as was seen amongst the Melicertidge, and that
such atoms drawn together by the action of the ciliary organs
were caused to adhere from contact with some sort of saliva or
secretion. It was very interesting to find the same thing
occurring in these specimens from the West Indies.

Mr. Western could not think that the formation of these
tubes was merely accidental, though they might, like those of
CEcistes, be partly formed of extraneous matters which became
attached to them ; but the way in which the Rotifer retired
into its tube when alarmed and then came out again to feed
was, he thought, evidence that the tube was designedly con-
structed.

Mr. Grrenfell noticed that the authors of both papers had
made reference to the drying up of Rotifers, but if they were
revived it would show that they "were not dried up — though
what they had seen might have come from eggs. The subject
had been recently dealt with in " N^atural Science," and there
it was shown that they could not be revived.

Mr. Western said he had no doubt at all as to the possibility
of drying up Rotifers and then reviving them. He had fre-
quently had them dried upon paper and had revived them under
the microscope, and had been able to revive Rotifers after being
dried for two years.

242

Mr. Bryce said the question raised in " Natural Science " had
more particularly to do with Furcularia forficula, and he could
not speak from experience as to that ; but as regarded Philodina
Roseola^ he was sure that it could be revived after long periods
of drying.

Mr. Hailes said there could be no doubt about the matter
because it had been seen over and over again.

The President noticed the statement in " Natural Science,"
and thought it was certainly too dogmatic, because the facts
were very well known to numbers of microscopists who had
made the experiments for themselves.

Mr. Ingpen was rather surprised that any question should be
raised about this matter, because the experiments made by Mr.
Henry Davis many years ago were quite conclusive.

Mr. Bryce said that Mr. Davis read a paper on the subject
before theR.M.S., which was pablished in the " Monthly Micro-
scopical Journal " for 1873. The experiments detailed were
commented upon by Dr. Hudson and regarded by him as fully
explaining the facts. Mr. Davis found that the apparently dry
balls were really moist inside, being protected from complete
desiccation by the hardened gelatinous coating. With regard
to the Rotifers and their tubes, he thought that those which had
become used to living in this way would no doubt seem nervous
if turned out of them. He did not mean to imply that they
had no purpose in making them, but his contention was that
the secretion given off from the lips would naturally cause
particles to adhere to one another around the Rotifer, and there-
fore, though the construction of the tube might not be in the
strict sense purely accidental, it was accidental to the process
that it should come to be largely formed of extraneous matter.

Mr. King said that these Rotifers did not construct their tubes
by drawing matter towards them and working it up for the
purpose, but they simply took such material as they found
ready, and adapted that to the formation of a dwelling. He
had isolated the one which he had described and kept it
thoroughly under observation.

The President said the paper had proved to be an interesting
one, and had led to discussion which had brought out some
useful points. Their thanks were heartily accorded to Mr.
King for his communication.

243

Anuouiicemeiifcs of meetings, etc., for the ensuing month were
then made, and the proceedings terminated with the usual con-
versazione.

October 7th, 1892. — Conversational Meeting.
The following objects were exhibited : —
Zoothaminium arhuscula Mr. F. W. Andrew.

Bistyla mermis ") ^i/r -r^ -r.

n ii'j- -n f n. sp. Mr. D. Bryce.

Pedalion mirum Mr. W. Burton.

Thunbergia alata, Section Mr. G. E. Mainland.

AmphipJiora elegans Mr. H. Morland.

October 21st, 1892. — Ordinary Meeting.
E. M. Nelson, Esq., F.R.M.S., Vice-President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
Members of the Club : — Mr. J. L. Luscombe and Mr. Thomas
W. Hinds.

The Secretary said he felt sure that every member of the
Club would hear with extreme regret the announcement of the
death of their esteemed friend and the Editor of their Journal,
Mr. H. F. Hailes, which occurred only that morning. His own
connection with Mr. Hailes had for many years been a very
close one, and he felt the loss to be a peculiarly personal one ;
but the members of the Club generally to whom Mr. Hailes
had so long been known would, h^ knew, very largely share in
that feeling. Of course the Committee at their meeting that
evening had taken special notice of this sad event, and had
passed a resolution of sympathy, which would be forwarded to
the family of their late friend. The resolution was as follows :
" The Committee of the Quekett Microscopical Club have heard
with deep regret of the death of their esteemed colleague, Mr.
Henry F. Hailes, one of the original members, and for many
years Foreign Secretary and Editor of its Journal, and they

244

desire to express their profound sympathy with his family in
their bereavement."

The Chairman said that they met that evening under circum-
stances of great sorrow. Although he had not "been brought so
much into personal relation with Mr. Hailes as Mr. Karop
had, yet he had known him for a great number of j^ears, and
could say that in all his business transactions with him in connec-
tion with the Journal he had never met with anyone more ready
to give his help whenever he went to him for his advice or assist-
ance in any matter connected with the Club, and looking back
upon his connection with them, he could not recollect a single
meeting when Mr. Hailes was not present. He could only feel
with others that a terrible blow had fallen upon the Club.

Mr. J. G. Waller inquired if the resolution which had been
agreed to by the Committee could not be adopted by the whole
of the meeting ? He thought this would be a course which
would strongly recommend itself to the members who were
present.

The Chairman at once agreed to this suggestion, and having
put the resolution to the meeting, declared it to be unanimously
carried.

The following donations to the Club were announced : —
" The American Monthly Microscopical ) j^ Exchang

Journal" ... ... ... ... J

" Science Gossip " ... ... ... ... „ ,,

" Annals and Magazine of Natural ^ P . i r]

History" ... ... ... ... )

" Journal of the Royal Microscopical -^ ^ f] S ' f

Society" \ ""^"^ ^^ '''^'^^*

" Report of the Brighton and Sussex

Natural History Society" ...
" Bulletin of the Minnesota Academy of )

Natural Sciences " ... ... ... )

" The Essex Naturalist " From the Editor.

*' Proceedings of the Royal Society " ... From the Society.

" Le Diatomiste " ... ... ... ... From the Editor.

" Proceedings of the Croydon Natural )

History Society " ... ... ... j

" The British Moss Flora," Part XIY.
" La Nuova Notarisia "

1

245

The thanks of the Club were voted to the donors.
Mr. Karop exhibited and described a microscope made by
Messrs. Swift almost entirely of alumininm, with the result that
the weight was reduced from 71b. 13oz, in the brass model to
21b. lOJoz. in the instrument before them. He believed this
was an absolute novelty, and would commend itself at least to
those persons who were much in the habit of carrying their
microscopes about with them. Certain parts, such as rack and
pinion, and screws, had necessarily 'to be made of another metal,
and some trouble had been experienced in the matter of soldering
and polishing. The price could not at present be stated.

The Chairman congratulated the makers upon their achieve-
ment ; this was certainly the lightest microscope he had ever
handled, and he had rarely seen anything more beautifully
finished.

Mr. Morland said he believed a means of soldering aluminium
had recently been discovered. It w^as mentioned in the " English
Mechanic ; " he thought it was some preparation of chloride of
silver which was used. It could also be united by a process of
electric welding. It was coming largely into use for soldiers'
accoutrements on account of its extreme lightness.

The Secretary said he had received from Mr. Stevens a small
sample of Diatomaceous earth from under the market-place at
Christchurch, New Zealand, which had been handed to Mr.
Morland for examination.

Mr. Morland said the Christchurch deposit contained a
quantity of Surirella contorta and other forms. It was rather
sandy, and therefore not very easy to pick out ; but some good
specimens could be got with patience.

The Secretary said he had also received a batch of communi-
cations from Dr. Arthur Meade Edwards, which he should
have been glad to have read if possible, but, unfortunately,
having been written with an electric pen or some similar con-
trivance, the result was so far illegible that it was hopeless to
attempt to decipher it.

Mr. C. L. Curties exhibited a small stand carrying a bottle
with polished sides, intended for filling wdth different solutions,
for the purpose of obtaining monochromatic light; also two
slides of Bhomboides, one mounted in quinidine and the other in
styrax. For photography there was some advantage in quini-

246

dine over styrax, but he found that it was difficult to keep.
The specimen shown had crystallized after the first month, but
when remelted it was quite restored.

Mr. Karop said that what remained of the Whomhoides in his
slide certainly came out very well.

The Chairman said that quinidine was a substance which
seemed to him to have the greatest possibilities ; it certainly
was the most brilliant resolving medium with which he was ac-
quainted, and he hoped that all who could work at it would do
their best to try and find some means of securing its permanence.

Mr. Morland said that if after a time it was found to re-
crystallize all they had to do was to warm it up again, and it
would be all right.

Mr. C. L. Curties pointed out the necessity for not "ringing"
slides so mounted, otherwise when warmed the varnish would be
likely to run in.

The Chairman exhibited and described a new form of sphero-
meter, made from his own designs, for the purpose of measuring
the curvatures of lenses of various sizes.

Mr. Ashe being unable from cold to read his paper " On the
Determination of Optical Tube Length," it was read by the
Secretary.

The Chairman thought this was a valuable communication
giving them an original and very simple formula for getting the
equivalent of the tube length, and he would advise every micro-
scopist to write it on the first page of his note-book. It fur-
nished them with a ready means of getting the arithmetical
equivalent, and from that they could always ascertain the power
of an unknown objective. The only previous way was to find
the diameter of a projected image at a great distance — say five
feet — by which any small error in the distance would be
absorbed; but the manner suggested by the paper was very
much more simple, and it had only to be known and appreciated
to ensure its being used every day.

Mr. Western read his " Notes on Rotifers," illustrating the
subject by drawings on the black board.

Mr. Bryce congratulated Mr. Western on having been able to
clear up some doubtful points, and thought it was a great help
to those who took an interest in such matters to get them so
nicely described.

247

The thanks of the Club were cordially voted to those gentle-
meii who had communicated papers, etc., to the meeting.

The Secretary said that in consequence of the death of their
Editor the Committee had been placed in some difficulty with
regard to the Journal, but he was glad to be able to announce
that Mr. Nelson had very kindly come to their assistance by
undertaking the duties of Editor pro tern.

Mr. Nelson said he should be very glad to render what service
he could in the matter ; but they might be sure he would not
have undertaken the work had it not been for the assurance
that he should have the kind assistance of Mr. Karop in con-
nection with it.

Announcements of meetings for the ensuing'month were then
made, and the proceedings terminated with the usual conver-
sazione, at which the following objects were exhibited : —

Cheap German Lens by Leitz

Fredericella sultana

Stem of Juniper, Trans. Sec.

EucManis diletata ...

Nav. Rhomhoides, in Quinidine

„ „ in Styrax

Chcetoceros, sp., in very remarkable

and hitherto undescribed sheaths,

apparently membranous
Brachionus hrevispinus, Ehr., new to

England
Crystals of Cinchonidine, Mount 20

years old ... ...

}

Mr. A. Ashe.
Mr. F. W. Andrew.
Mr. W. J. Brown.
Mr. W. Burton.

Mr. C. Lees Curties.

Mr. J. G. Grenfell.

Mr. C. Rousselet.

Mr. Geo. J. Smith.

November 4th, 1892. — Conversational Meeting.
The following objects were exhibited : —

Macrothrix laticornis ... ... ")

Euchlanis triqueta j Mr. W. Burton.

Hemiaulus alatus ... ... ... Mr. H, Morland.

Funaria hygrornetrica, with pseudo-
scopic binocular

Mr. Alpheus Smith,

248

November 18th, 1892, — Ordinary Meeting.
E. M. Nelson, Esq., F.R.M.S., Yice-President, in the Chair.

The minutes of the preceding meeting were read and con-
firmed.

The following gentlemen were balloted for and duly elected
members of the Club: — The Rev. J. C. Pratt, Mr. Leonard
Sandall, Mr. A. S. Ussher, and Mr. Frank Orfeur.

The following donations to the Club were announced, and the
thanks of the meeting were given to the donors : —
"Proceedings of the Geologists' I From the Association.

Association" ... ... ... J

" The Essex Naturalist " „ Editor.

"The Botanical Gazette" „ Publisher.

" The Microscope " ... ... ... „ „

" The American Monthly Microscopical)

Journal" ... ... ... f

"Proceedings of the Belgian Micro- ^ (^ • ,

scopical Society" ... .".. j

r 55 55

"Proceedings of the Brighton and|

Sussex Natural History Society" /
" Journal of the Royal Microscopical

Society"
" Science Gossip " • ... ... ... „ Editor.

" Annals of Natural History " ... ... Purchased.

" Practical Photo-Micrography," Bous- 1 j.^,^^ ^^^ ^^^^^^

field 3

The Chairman called attention to a new book by Mr. Bous-
field, " On Photo-Micrography." He had not yet had the
opportunity of reading it, but, so far as he could see from
glancing through, it seemed to be a work well worthy of the
attention of all who were interested in the subject.

Mr. Karop caused considerable amusement by reading some
extracts from a newspaper report of the recent Soiree of the
Ealing Microscopical Society, taken from the "Middlesex
County Times," of November 5th, which afforded a striking
illustration of the knowledge possessed by the average news-
paper reporter, and his methods of expressing it where
scientific matters were concerned. According to this report,

249

amongst many remarkable things shown by Members of the
Quekett Club, they were informed that "Mr. E.Bartlett caused
his microscope to disclose that which lay concealed in the
inside of heather," "Mr. T. Simpson enlarged the vision of
the human skin," and " Mr. F. A. Parsons illuminated the com-
position of bog-moss." The climax was, however, reached by
the statement that "in addition to illustrations under the
microscope, Mr. C. Jones brought an achromatic spectroscope''
this being what Mrs. Malaprop would call " a nice derangement
of epitaphs."

Mr. Watson exhibited and described a new form of the
" Edinburgh Student's Microscope," in which this well-known
instrument was mounted upon a tripod base.

Mr. Karop thought that in the form now shown this was
certainly a very nice microscope, but he could hardlj^ see why
it should be cat away so much at the back ; possibly this did
not actually affect its strength, but it had the appearance of
weakening it.

The Chairman said this microscope had been some time in
his possession, having been sent to him specially that he might
examine the fine adjustment, which had been somewhat
severely criticized at a meeting of the Royal Microscopical
Society some time ago. His opinion was asked about it at the
time, but he had not then any opportunity of- examining it, but
the adverse remarks were then made on the assumption that
the fine adjustment was made on the Zentmayer plan, which it
seemed had always gone wrong after a short time in ordinary
use. It appeared, however, on examination that this differed
very materially from Zentmayer's, inasmuch as the groves were
thoroughly sprung, so that if it began to show signs of wear it
could always be tightened up again by turning the screws.
There seemed to be no difference^ in construction between this
and the similar pattern of Messrs. Swift, except that the lever
in one was placed vertically, and in the other it was at right
angles. He considered this to be a very nice instrument with
its present stand ; the horse-shoe foot was always very heavy,
and for all that it was easily thrown over, so that both for
lightness and steadiness he greatly preferred the tripod.

The Chairman exhibited a simple apparatus for projecting
the image of any large object under low power upon paper

250

placed below it, so as to enable anyone to draw it. The striic-
tore of the arrangement and the method of using were
described. In reply to a question it was explained that the
image obtained was inverted and transposed, as seen in the
microscope, and not as was the case with drawings made with
the camera lucida, which corrects the inversion, but leaves the
transposition.

Mr. Western read some interesting extracts from a letter
received from Surgeon Gunson Thorpe, R.N., whose ship at the
date of writing was lying in the Yangtze-Kiang river, on the
China Station. The writer mentioned the extreme richness of
the fresh water pools of the district as regarded Rotifers, and
promised in a future communication to send detailed descrip-
tions of some new and remarkable forms of Melicerta, Trocho-
sphera, and Lacimilaria which he had recently met with.

Mr. Scourfield read his paper "On the Entomostraca of
Wan stead Park."

The Chairman was sure all present would agree with him
that Mr. Scourfield had given them a most excellent paper, in
which the subject had been treated in a most masterly way.
The publication in the Journal of the curves, which had been
drawn in illustration of the abundance of various species at
different times in the year, would add greatly to the interest of
the paper when printed.

Mr. Karop was very glad that Mr. Scourfield had come
forward with this paper on a subject which had been so
little touched upon. When he read his last paper the hope
was expressed that he would follow it up by others, as it
appeared that they had never before had a paper read at the
Club on the Entomostraca.

Mr. T. F. Smith read a paper " On Photo-Micrography, with
Iso- Chromatic Plates," the subject being illustrated by a
number of photographs, which it was explained had been taken
by Messrs. Swift's latest series of objectives made with Jena
o-lass. In the case of the Jin. no eye-piece had been used.

The Chairman thought some of these photographs were very
beautiful ; so good, indeed, that they bore examination with a

lens.

Mr. Karop said he had been also