Jvojjal Sorictp of :llrfs.

THE JOURNAL

OP THE

d|i«lt^tt

Microscopical Club

EDITED BY
A. W. SHEPPARD, F.R.M.S.

SECOND SERIES.

VOLUME XIII.

1916-1918.

♦•••#•»•••

[Published for the Club]
WILLIAMS AND NOKGATE,

14, Henrietta Street, Covent Garden, London.

PRINTED BY

HAZRLL, WA.T30N AKD VDfEY, LD.,

LONDON AND AYLESBURY.

Ill

CONTENTS.

PART No. 78, APRIL 1916.
Papers.

PAGE

A. E. Hilton. On the Formation of Sporangia in the Genus

Stemonitis (Plate 1) . . . . . . .1

James Burton. On a Species of Aleurodes .... 7

G. T. Harris. The Collection and Preservation of Desmids . 15
Arthur Dendy, D.Sc, F.R.S. Presidental Address — Some

Factors of Evolution in Sponges . . . . .27

W. Milne, M.A., B.Sc, F.R.S. E. On the Bdelloid Rotifera of

South Africa. Part 1. (Plates 2-6) . . . .47

Notes.
J. T. Cook. A Simple Trough for Pond Life (Figs. 1 and 2) . 85

Proceedings, etc.

Proceedings from October 26th, 1915, to February 22nd, 1916,

inclusive ......... 87

Fiftieth Annual Report, 1915 . ...... 99

Treasurer's Report, 1915 . . . . . . . 105

PART No. 79, 'NOVEMBER 1916.

Papers.

Chapman Jones. The Secondaries or Dotted Structure in

Pinnulariae (Plate 7). . . . . . .107

A. A. C. Eliot Merlin, F.R.M.S. On Nitzschia singalensis as a

Test-Object for the Highest Powers (Plate 8) . . .111

M. A. AiNSLiE, R.N., B.A., F.R.A.S. Nitzschia singalensis : A

Note on Mr. Merlin's Paper . . . . . .113

H. Wallis Kew. An Historical Account of the Pseudoscorpion-

famia of the British Islands (Figs. 1 and 2 in text) . .117

A. E. Hilton. On Sporangial Characters of Mycetozoa and

Factors which influence them (Plate 9. Figs. 1 and 2 in

T'OXuj ■ • « • • • • • • • k O i

W. Milne, M.A., B.Sc, F.R.S.E. On the Bdelloid Rotifera of

South Africa. Part II. (Plates 10-14) , . .149

iv CONTENTS.

Proceedings, etc.

'}

PAGE

Notices of Books . . . . . . . . .185

Proceedings from March 28th to June 27th, 1916, inclusive . 188

Obituary Notices :

B. T. Lewis, F.R.M.S 201

Feedeeic Enock, F.L.S., F.R.M.S., F.E.S. . . .203

PART No. 80, APPvIL 1917.
Papers.

David Beyce. Notes on the Collection of Bdelloid and other

Rotifera. (Figs. 1 and 2 in text) ..... 205

Aethur Dendy, D.Sc, F.R.S, The President's Address. The
Chessman Spicule of the Genus Latrunculia ; a study in
the origin of specific characters, (Plates 15-17) . . 231

G. T. Hareis. The Desmid Flora of Dartmoor. (Plates 18 and

19) 247

C. D. Soar, F.L.S., F.R.M.S. Two New Species of Hydracarina
or Watermites, Dartia Harrisi and Eylais Wilsoni (Plates
20 and 21) 277

Proceedings, etc.

Notices of Books ......... 283

Proceedings from October 24th, 1916, to February 27th, 1917,

inclusive ......... 287

Fifty-first Aimual Report (191 6) 298

Treasurer's Report ........ 305

PART No. 81, NOVEMBER 1917.

Papers.
W. M. Bale, F.R.M.S. Note on the Measurement of Magnifying

Powers. (Fig. 1 in text) ...... 307

Maurice A. Ainslie, R.N., B.A., F.R.A.S. The Measurement

of Magnifying Power. A Note on Mr. Bale's Paper . 315

C. F. Rousselet, F.R.M.S. Some further Notes on Collecting

and Mounting Rotifera . . . . . .321

Notes.

Technical Optics ......... 329

Notices of Books :

On Growth and Form : D'ArcyW. Thompson . . . 333

Proceedings, etc.

Proceedings from March 27th, 1917, to June 26th, 1917, inclusive 336

Obituary Notices :

Robert Beaithwaite ....... 350

Alpheus Smith (Portrait) 351

CONTENTS.

PART No. 82, APRIL 1918.
Papers.

PAGE

A. B. Rendle, M.A., D.Sc, F.R.S. The President's Address :
The Use of Microscopical Characters in the Systematic
Study of the Higher Plants . . . . . .353

'G. T. Harris. On Schisfostega osmitndacea Mohr. (Plates 23

and 24, and Figs. 1-3 in text) . . . . .361

W. Williamson, F.L.S., F.R.S. E., and Charles D. Soar, F.L.S.,

F.R.M.S. Lebertia sejveiV^&XiQv. (Plate 25). . . 375

Notes.

Edward M. Nelson, F.R.M.S. On the Measurement of Magni-
fying Power ........ 379

Edward M. Nelson, F.R.M.S. Carl Dietrich Ahrens . .381

Prof. Frederic J. Cheshire, C.B.E. Carl Dietrich Ahrens . 383

Proceedings, etc.

Proceedings from October 23rd, 1917, to March 12th, 1918,

inclusive ......... 385

Fifty-second Annual Report (1917) ...... 399

Treasurer's Report (1917) ....... 405

Table for the Conversion of English Metrical Linear Measures . 406

PART No. 83, NOVEMBER 1918.

Papers.
Sir Nicholas Yermoloff, K.C.B., K.C.V.O., F.R.M.S. Notes

on some Intermediate Forms of the Genera Navicula and

Cymbella. (Plates 26-28) 407

Prof. G. S. West, M.A., D.Sc, F.L.S. A Further Contribution

to our Knowledge of the Two African Species ot Volvox.

(Plates 29 and 30) 425

Edward M. Nelson, F.R.M.S. The Binocular Microscope . 429

Notes.

Edward M. Nelson, F.R.M.S. Microscope Eye-pieces . . 437

Edward M. Nelson, F.R.M.S. Oil-immersion Dark-ground

Illuminator (Fig. in text) ...... 438

Proceedings, etc.

Proceedings from April 9th, 1918, to June 11th, 1918, inclusive . 439
Index to Vol. XIII 449

Vll

LIST OF ILLUSTRATIONS.

PLATES.

Portrait of the late B. T. Lewis, F.R.M.S., facing page 107.

1. Phases in the formation of Sporangia of Stemonitis.

2-6. Bdelloid Rotifera of South Africa.

7. The Secondaries of Pinnulariae.

8. Nitzschia singalensis.

9. Typical Sporangia of Mycetozoa.
10-14. Bdelloid Botifera of South Africa.

15. Development of Discorhabd in Latrunculia bocagei B. and D.

16. Development of Discorhabd in Latrunculia apicalis B. and D.

17. The Discorhabd of Latrunculia apicalis B. and D.
18-19. Desmid flora of Dartmoor.

20. Dartia Harrisi gen. et sp. nov.

21. Eylais Wilsoni sp. nov.

22. Portrait of Alpheus Smith.
23,24. Schistostega osmundacea Mohr.

25. Lebertia sefvei Walter.

26. The " Monmouthiana Integral."

27, 28. Variation in the Genera Navicula and Cymbella.
29, 30. Volvox Bousseletii et ajricanus G. S. West.

FIGURES IN THE TEXT.

Page 53. Mastax of Monoceros falcatus sp. nov.

,, 85. A simple trough for pond-life.

,, 118. Beduced outline of the "crab-like insect" of Hooke, pi.

xxxiii. fig. 2 [= Cheiridium museorum (Leach)].

,, 119. Cheridium museormn (Leach), from Kew, pi. v., fig. 13,

,, 140. Conventional figures of sporangia of Mj^^cetozoa.

,, 144. Phases in development of sporangia of Comatricha nigra.

,, 227. Apparatus used for collecting, etc., bdelloid Botifera.

,, 229; Apparatus used for collecting, etc., bdelloid Botifera.

,, 301. Diagram : Measurement of magnifying powers.

,, 303. " The Shepherd's Hut,"

,, 368. Photo- synthetic system of light.cells (after Noll).

,, 371. Diagram of light rays in obconical cell (after Noll).

,, 438. Oil-immersion dark-ground illuminator.

<f^^¥i^

THE JOURNAL

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OF THE

^uekctl M^icrosc apical dt^htb.

ON THE FORMATION OF SPORANGIA IN THE

GENUS STEMONITIS.

By a. E. Hilton.

{Read October 26th, 1915.)

Plate 1, Figs. 1-4.

One of the most aoandant forms of Mycetozoa in all parts of the
world is Stemonitis ; a genus easily recognisable by the dark-
brown sporangia, usually 0*5 to 0*75 of an inch high, generally
crowded together, which look something like diminutive bull-
rushes, on slender black stalks.

Familiar as these are to some of our members, it is probable
that not many have had an opportunity of watching the actual
transformation of a plasmodium into sporangia. This process
is so interesting that you will, I think, like to have a description
of it, taken from my notes made at the time of a recent obser-
vation. By way of preface, it is well that I should remind
you that in Stemonitis the stalk is continued upward as a
columella nearly or quite to the apex of the sporangium. From
this columella the capillitium branches in all directions, and
surrounds the sporangium with a surface network of extremely
delicate meshes, through which the spores finally escape.

In the middle of August last, after six weeks of frequent heavy
rains, I took advantage of unusually favourable conditions, and

JouRN. Q. M. C, Series II.— No. 78. 1

2 A. E. HILTON ON THE FORMATION OF

searched for Mycetozoa in the Highgate Woods. An old tree
stump to which I came was hidden by the leaves of branches
which had sprouted from it ; but on drawing the branches aside
I made a welcome discovery. Near the top of the stump were
the blackened remains of an old and leathery fungus ; and on
these sooty-black and fairly level platforms there were several
patches of milk-white plasmodium which appeared to have
oozed from the stump. The smallest patch was about 0*125
inch, and the largest about 1'125 inch in diameter; all being
probably portions of the same plasmodium, which had found
its way to the surface of the fungus by different channels
and in varying quantities. Carefully severing the fungus from
the stump, I transferred the treasures to my collecting-box. It
was on the stroke of noon, and I had found them only just in
time, as developments began almost immediately.

The plasm was in a semi-fluid condition, and consequently
the patches were, at first, of a somewhat rounded and flattened
cushion-shape (PL 1, fig. 1). The surfaces soon assumed a frothy
appearance, and in about a quarter of an hour the cushions
were covered with bubble-like hemispheres, of uniform size,
somewhat translucent, close together, and slightly angled by
mutual pressure. In this condition they were charming objects,
resembling nothing so much as tiny blanc-manges, moulded
into perfect shape (PL 1, fig. 2).

Here let us pause a moment to inquire what, so far, had really
happened. A simple question, but in biology everything is com-
plex, and of complicated phenomena only abbreviated accounts
can be given. Bear in mind that in the Mycetozoa, spore-
formation is essentially a process of rejuvenation by purifi-
cation. A Plasmodium about to form sporangia includes not
only its own proper nuclear elements and their cytoplasm, but
also an excess of fluid, and substances, more or less dissolved,
which have to be either secreted or excreted before this renewal
of youth can be effected. The excess fluid gradually evaporates,
and of the superfluous substances the cruder elements are

SPORANGIA IN THE GENUS STEMONITIS. 6

the first to be precipitated. In the case before us it is evident
that secretion and evaporation had sufficiently advanced for the
partially purified plasm, in accordance with the laws of colloidal
physics, to begin dividing into smaller masses ; each separating
mass being indicated by one of the surface hemispheres, and
furnishing the material for a distinct sporangium. While these
results were coming to light, other developments commenced
which were to appear later on.

To proceed. By 4 p.m. the whiteness of the upper surfaces
had changed to a creamy tint, or more correctly to a very light
pale brown. Also the area covered by the hemispheres was
contracting and at the same time rising to a higher elevation.
That is to say, each aggregation of plasm-masses was growing
taller and beginning to assume a somewhat conical shape (PL 1,
fig. 3). The lower two-thirds of the plasm had become columnar ;
the mass immediately beneath each surface hemisphere being
now at the summit of a pillar, forming as it were its capital.
The pillars were milky- white, semi-transparent, and of smaller
circumference than the tinted capitals which crowned them.
This means that although the plasm masses of the upper third
were still crowded together, there were clear spaces between
the pillars which supported them. The artistic effect was
strangely beautiful. Each cluster of the half -formed sporangia
now seemed to be a miniature temple of surprising loveliness
not easily forgotten when once seen.

In another half-hour black stalks were visible at the centres
of the pillars. At 6 p.m. the sporangia, now obviously those
of Stemonitis, were nearly half an inch in height ; and by
8.30 the whole of the plasm had risen clear of the fungus, and
was resting on a forest of stalks, 0*125 inch long. On the
surface of the fungus from which it had ascended, the plasm
had left a whitish sedimentary deposit, which formed a mem-
branous hypothallus ; and this subsequently assumed a silvery
hue. On the tops of the clusters of sporangia some watery
plasm was all that remained of the hemispheres, which had

4 A. E. HILTON ON THE FORMATION OP

melted into, and been absorbed by, their respective pillars, as
tlie sporangia lengthened upwards to their full height. At
this stage the general appearance of each cluster suggested a
diminutive canvas tent with a flattened top, spreading con-
siderably towards the bottom, and held in position by black
cords (PL 1, fig. 4). Very striking indeed were these successive
developments.

Again we pause to ask, as before, what had really happened.
What were the inward facts of which these metamorphoses were
the outward signs ? The essential process, the clarification of
the plasm, was evidently proceeding apace. That was shown
by the excretion of the hypothallus and the secretion of the
stalks ; and was further emphasised by the alteration in the
colour of the plasm. For the creamy or light-brown tint
now prevailing indicated that finer secretions from purer plasm
were also being deposited to form the branching capillitia and
the delicate superficial nets enveloping the sporangia. The
elimination of these materials, concurrently with loss of fluid
by evaporation, would inevitably alter the physical strains of
the colloidal plasm ; and the formation of the columns, and
the climbing of the plasm up the stalks, in spite of gravitation,
was plainly a shrinkage movement caused by a progressive
strengthening of the surface tensions. Thus far, however, the
processes were all preliminary ; the most important change was
impending.

At 10 p.m., ten hours after the emergence of the plasmodium
from the tree-stumps, the sporangia had practically attained th«ir
ultimate shape, and were a shade darker, though still of a light
brown or buff colour. By 8 a.m. next day they were nearly
black ; and by 8 p.m. on that date they were a dark purplish
brown. The colour became a little lighter, or rather browner,
as the sporangia subsequently dried off ; but the beauty had
gone.

What had occurred in this closing stage ? The living plasm
had lent its charm to all the previous phases. Why had it now

SPORANGIA IN THE GENUS STEMONITIS. O

witlidrawn from sight behind so dark and dull a screen ? What
had happened was this : it had achieved its purification, gained
its end, and passed into a state of rest ; ready, on reawakening
under suitable conditions, to recommence its vital activities
with all the vigour of youth perfectly renewed. In other words,
the extrusion of its impedimenta had made it possible for the
nuclear elements of the plasm to adjust themselves to the
process of spore -formation. Immediately before the actual
formation of spores, the multitudinous nuclei in the plasm
greatly increase in number, the clarification of the plasm clearing
the way for the growing nuclei to divide. An equilibrium of
balanced colloidal conditions then ensues ; the nuclei becoming
suspended in geometrical order, and at equal distances from
each other, throughout the entire mass. This is brought about
by the mutual opposition of their radiating energies. Each
nucleus thus becomes the centre of an individual spore. By a
final act of purification the remaining impurities are expelled
to the boundaries of the spheres of nuclear influence, where
they harden into spore-cases. This is followed by further
drying and shrinking ; each case containing its nucleated plasm-
speck is separated from the rest, and the process of spore-for-
mation is complete. The life of an individual plasmodium passes
into the lives of innumerable spores ; the problem of individu-
ality, as thus presented by the Mycetozoa, being one you can
ponder at leisure.

A word of warning is perhaps necessary. In principle, the
methods of spore-formation are analogous throughout the
group ; but not always do the inward processes find such striking
expression as in the forms we have been studying. We must
not, however, regard these forms as having any special or excep-
tional significance. They are but transient phases of the plastic
plasm, which arrest us by their beauty and disappear. Even
the beauty is in this, as in other cases, the lover's gift ; and
to the numberless spores it matters not at all what the shape of
the sporangium may be. The delicate network of the capillitium

6 A. E. HILTON ON THE FORMATION OF SPORANGIA

of Stemonitis is a good object for the microscope ; but it is
only a by-product, and of no biological importance. When the
spores disperse to fulfil their next function, all other structures
are left behind to perish ; but we know that if the life which
created them survives, the forms we have admired will reappear.

Description of Plate I.

Fig. 1. Pulvinate form of plasm-masses at 12 noon, x 3.
,, 2. Frothy surface appearance at 12.15 p.m. x 3.
,, 3. Semi-columnar form at 4 p.m. x 3.
,, 4. Cluster of stalked sporangia developed by 8.30 p.m. x 3.

Journ. C^uekelt Microscopical Club, Ser, 2, Vol, XIII,, No. 78, April 1916.

JOURN. Q. M. C.

Ser. 2, Vol. XIII., PI. 1.

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ON A SPECIES OF ALEURODES.

By James Burton.

{Head December 2Sth, 1915.)

1 AM desirous of bringing under your notice a few facts concerning
an interesting little fly belonging to the genus Aleurodes. I am
not quite sure of the specific name, not having access to detailed
and descriptive lists of the species, but probably it is ^. hrassicae,
a not uncommon form and, as its specific name implies, found on
cabbages. The definition of the family given in the Cambridge
Natural History Ls as follows : " Minute insects with four mealy
wings; seven-jointed antennae; two jointed feet, terminating in
two claws and a third process." It is not quite a new subject to
the Club, as Mr. Lewis some years ago described and beautifully
figured a species that had been sent to him from South Africa.
This was a new species, and was named by Mr. Maskell — an
authority on the group — Aleurodes aspara/ji, as it was found on
a species of Asparagus, grown in Natal, Mr. Lewis's paper
will be found in vol. vi. 2nd series of the Journ. Q. M. C. The
paper was read in April 1895, and is most useful, in fact it is
the only description in any detail w^ith which I am acquainted.
Mr. Lewis has been so kind as to lend me some of his mounted
specimens.* The pupae of A. asparagi are especially interesting,
as they differ in several important respects from those which I
have found. These pupae have handsome plumes composed of a
wax-like substance secreted by the insect, arranged in rows along
the back and sides ; these are entirely absent in my specimens,
which have only a kind of frill — of the same structure, however —

* Mounted preparations of Aleurodes hrassicae were exhibited as well
&9 Mr. Lewis's preparation of A. asparagi from South Africa.

8 JAMES BURTON ON A SPECIES OF ALEURODES.

round the lower edge of the body; this is also present in A. asparagi^
though hidden by the more handsome side plumes.

The occurrence which made me wish to bring the subject
before you has only recently happened, and is so interesting that
it seems worth recording.

During most of the summer a fuchsia remained on an inside
window-ledge. In September it was condemned to the garden,
and on carrying it out a quantity of honey- dew was noticed on
many of the leaves. As there is a connection between the presence
of honey-dew and certain fungi, and this being of interest to me,
I at once looked the plant over carefully. As soon as the leaves
were disturbed, several of these little white flies rose up, and they
proved to be quite numerous on the plant. Ever since at inter-
vals it has been possible to find a few on the leaves, and only
yesterday, without any thorough search, two living Aleurodes
were detected.

The fly is a very small and fragile creature ; when living it is
almost exactly 1 mm. long. It has an orange-coloured body,
with well-marked head, thorax and abdomen. There are two
dark-pink compound eyes, which are worth notice ; they are oval
in outline, each with a constriction across the long axis, but
which does not completely divide them. There is a small simple
eye above each of the compound ones. The antennae are seven
jointed, the two basal segments larger than the others. There are
four membranous wings, without nervures ; apparently these,
like the body, legs and antennae, are thickly covered with a
mealy white substance, and there seems little doubt that this
is a waxy exudation. The legs and feet are slender, the
tarsus with two joints, and terminating with two rather long and
slender claws, and a third process. Beneath the head is a curved
sword-like piercing and sucking rostrum, almost the length of the
thorax ; the end is sharp pointed and dark in colour. With this
the insect pierces the leaf of the host plant and sucks the juices,
just as do the Aphides, the well-known green flies, and the nearly

JAMES BURTON ON A SPECIES OF ALEURODES. y

related Coccidae or Scale-insects. The meal with which the whole
insect is covered is a troublesome feature in mounting, as it resists
water or weak spirit, and the use of stronger spirit usually results
in the waxy secretion being removed at the last stage of the
mounting and it then looks like dirt in the finished slide. With
turpentine, etc., for balsam mounts it is dissolved. On the dorsal
aspect of the last segment of the body there is a peculiar organ of
some interest. It is very well shown in the plates illustrating
Mr. Lewis's paper referred to above, but it is not easy to make out
distinctly in mounted specimens. The Aphides, as is well known,
secrete a large quantity of the sticky sweet substance known as
" honey-dew," and the Aleurodes do the same. In most species
of Aphides the organs which emit this substance are easily seen,
and consist of two tubes near the end of the body set one on each
side pointing upwards and backwards. It has been suggested
that possibly the organ in Aleurodes on the last segment may
serve the same purpose, but it seems scarcely likely considering
its structure. It is formed of a short, hollow, crater-like base,
from which projects a sort of papilla covered with hairs. On one
occasion I was examining a leaf with many pupae upon it, when I
was called away for about an hour. On my return a fly had
emerged, its wings were not quite perfectly extended. It was
covered with a glass and a drop of chloroform was run under,
and almost immediately that the creature felt its influence it
emitted a large drop of honey-dew. It was impossible to see the
precise spot from which it came, but it was between the wings
towards the anal end of the abdomen, and might have come
actually from the anus.

Aleurodes was formerly classed with the Scale-insects, but the
genus now forms a separate family under the name of Aleurodidae,
placed between the Aphides and the Scale-insects. There are
several reasons for this arrangement. The Aphides are not winged
except in the sexual stage. In the Scale-insects the male has two
wings only, the female none, while the imago of Aleurodes has

10 JAMES BURTON ON A SPECIES OF ALEURODES.

always four wings, in both male and female. But the chief diSer-
ence is in the metamorphosis which the insect passes through. As is
well known, much the greater number of Aphides are produced
viviparously from unfertilised females, and no true metamor-
phosis occurs, though there is some change as the insect develops.

Dr. Sharp in the Cambridge Natural History, vol. vi., says :

" These minute insects are at present a source of considerable
perplexity owing to the curious nature of their metamorphosis,
and the contradictory accounts given of them. In the earlier
stages they are scale-like and quiescent, being fixed to the under-
side of the leaf. The French authors Signoret and Girard state
that the young are hatched having visible appendages and seg-
mentation, but that after they are attached to the leaf the organs
gradually atrophy. Maskell states the opposite, saying that the
organs in the earliest stages are not usually recognisable, but
become visible after the growth of the insect.

" Heeger states that the larva undergoes three ecdyses, and he
gives the figures reproduced in the Cambridge Natural History.
If he is correct it would appear that the nymph undergoes a great
development. Reaumur, on account apparently of their great
metamorphosis, treated the species known to him as lepidop-
terous, though he correctly pointed out their distinctions. At
present we can only conclude that the Aleurodidae undergo a
metamorphosis of a kind peculiar to themselves, and requiring
renewed investigation

" Maskell has increased the number of species to about sixty.
We have three or four in Britain, one of which, A. brassicae, is ex-
tremely abundant on various kinds of cabbage in certain years."

I have quoted this account because, so far as the species which
I have had under observation are concerned, I am able to
supply some definite information on doubtful points.

A writer in The Journal of Micrology says :

" Another lodger is a very pretty moth-like fly. Its wings are
pure white except for a dusky marking on each ; they are covered

JAMES BURTON ON A SPECIES OF ALEURODES. 11

with exceedingly small scales which are fastened to the membrane
with a ' quiir as in the moths. When the fly is ready to deposit
her eggs, she selects a depression in the under side of an outer
cabbage leaf, and then lays from six to twelve dark- coloured eggs
in a group, while all around are strewn scales from the wings and
body. And yet the fly looks none the worse ! What happens
next is not quite clear, but a white fringe appears all around the
egg which fastens it to the leaf ; and upon turning it over I find
a tiny grub underneath, furnished with six legs, each armed with
a bent claw and a long stiff hair. The abdominal segments can
just be distinguished. From the thorax (?) projects a long,
straight sucker, which is driven deep into the leaf. I am not
quite sure whether the insect uses its egg shell for its first covering.
or whether it makes a scale ; but in a day or two the fringe dis-
appears, and the grub and its covering grow rapidly, until it looks
like a tiny Brazil nut, with the sharp edge upwards. Then one
day the ' nut ' splits along the edge and the perfect imago emerges.
During the time the grub was feeding it moved only about half
an inch from the spot where was laid the egg from which it de-
veloped. This fly is known as the Cabbage Powdered- wing Fly —
Aleurodes 'proletella.^^

This description tallies in most respects with what I have
observed. First, however, it may be said that the mealy substance
does not consist of scales with a quill as in the moths. I have
been very careful in the matter ; the mealy substance consists
of very short curved rod-like pieces. One might almost consider
them to be minute rods of wax forced out from pores and
curving in the process. There was nothing like a scale or a quill
to fasten it. In A. hrassicae the egg was a short cylinder slightly
curved with rounded ends, pale yellow in colour, with a darker
orange spot at one end. The young larva has legs, antennae, two
pink eyes, some few hairs or bristles but not of great length ; it is
of a pale transparent yellow with an orange-coloured patch, seg-
ments just visible ; it moves feebly, and probably does not move

12 JAMES BURTON ON A SPECIES OF ALEURODES.

far away from its first position. In the next stage it has settled
down, and thrown out a delicate fringe of waxy filaments round
the lower edge of the body, which seems to fix it to the leaf. It
now much resembles a Scale-insect. From this stage it appears to
increase in size, and develops a number of long glass-like brittle
processes from the back and sides, about twelve in number, and
becomes box-like, oval in outline, with sides of considerable depth ;
the side of the box is composed chiefly of the wax fringe, and the
edges are ornamented with curved glass-like hairs, shorter than
those already spoken of. The imago becomes gradually more
clearly visible in this which is the pupa stage ; at last the top of
the box is rent, usually across, but sometimes the lid is forced off
at one end, and the fly emerges a beautiful and delicate little object,
especially for the binocular microscope. I have tried to dry
them for opaque illumination, but they shrivel up and become
distorted and useless.

Like the green flies and the Scale-insects, no doubt Aleurodes
does damage to plants by sucking their juices, and when the
number present is great of course the damage would be consider-
able. But another, though somewhat indirect injury results from
the presence of any of these insects. The honey-dew secreted falls
chiefly on the upper surfaces of the lower leaves of the plants upon
which they are living, or upon the leaves of any plants growing
beneath them, and this honey-dew forms the substratum upon
which one or more species of fungi flourish. Mr. Massee in his
Text-hook of Plant Diseases refers to the sooty mould following
the white fly Aleurodes citri. One species is recorded as attacking
coconut trees, and is named Aleurodes cocois. A. hrassicae and A.
proletella both occur on cabbages, while A. citri is very injurious
in many parts of the world on trees of the Citrus group, doing
great damage to orange and lemon fruit. Mr. Lewis's specimens
occurred on a species of Asparagus, apparently grown for orna-
mental purposes in Natal. The sooty fungus Fumago vagans is
extremely common, flourishing on the honey-dew secreted by the

JAMES BURTON ON A SPECIES OF ALEURODES. 13

green flies on very many kinds of trees and shrubs. In the
autumn the lower leaves of limes, oaks and shrubs growing
under them may be seen to be covered with a black soot-like
deposit, which upon examination proves to be a fungus. It is
opaque and of course obstructs the influence of the light on the
chlorophyll in those leaves on which it appears. Oranges which
usually arrive in this country in the spring are often covered
with a black deposit near the remains of the flower ; this is some
species of Meliola or Capnodium, fungi which flourish on the
excrement and secretion of the Scale-insects and no doubt of
Aleurodes also.

In a book published last spring, Insects and Man^ there is a long
account of almost heroic efforts which have been made to reduce
the loss caused to the Citrus growers of Florida by the depreda-
tions of Aleurodes citri, and the injury caused by the fungus which
almost always develops on the honey-dew secreted by the fly.
It is there stated that " the fungus does more harm to the plants
than the insects themselves, pervading, as it does, not only
the leaves, but the branches and even the fruit itself. More
than 45 per cent, of the Citrus groves of Florida are infested with
the fly, estimated to cause a loss of from 45 per cent, to 50 per
cent, of the value of an orange crop."

From experience obtained in other cases it was determined to
endeavour to find some insect, such as an ichneumon fly, or some
species of lady-bird, which would prey upon the Aleurodes. The
American Congress made a special grant towards a world-wide
search. At last the commissioners found in India a small reddish-
brown lady-bird about one-tenth of an inch long, and also a minute
hymenopterous parasite, both of which preyed upon the Aleurodes.
Efforts were made to get a supply of these foes upon the scene, but,
notwithstanding every endeavour, some difficulty always arose
which rendered it unsuccessful. Wardian cases were made in
which to bring over young citrus trees, with the Aleurodes fly upon
them, infested with the parasite ; and also the lady-birds from

14 JAMES BURTON ON A SPECIES OF ALEURODES.

whicli SO much was hoped, but only a few of the insects survived
the journey. In one instance it was found that twenty-eight lady-
birds had survived the journey ; they arrived in December, but at
the end of the winter only two were still alive. On examination
these proved to be both females, so obviously not much in the
way of reproduction could be expected. The whole account is
deeply interesting ; and it is to be hoped that sooner or later the
attempt will receive the reward it merits, even if the result should
be an extermination of the little Aleuiodes fly.

Journ. Qtiekett Microscopical Club, Ser. 2, Vol. XIII., No. 78, April 1916.

15

THE COLLECTION AND PRESERVATION OF DESMIDS.

By G. T. Harris.

{Read January 25th, 1916.)
. Communicated by James Burton.

The publication by the Ray Society of Prof. West's Monograph
of the British Desmidiaceae has induced so many microscopists
to concentrate their attention on this beautiful group that I feel
no apology is needed for describing methods that have proved
advantageous in my hands, both in collecting the material and
in dealing with it when collected. I am aware that the litera-
ture dealing with the collection and preservation of desmids is
not inconsiderable, and that formulae for mounting media have
been given with a generosity only equalled by their shortcomings ;
yet the hope that one may perhaps contribute some method that
shall prove more or less useful overcomes the reluctance to add
yet further to the burden of contributed matter on the subject.
The complaint not infrequently made by the uninitiated of
their lack of success in obtaining desmids may be due more to
their method of collecting than to the absence of desmids. The
orthodox ring-net will, of course, collect a considerable number
of unattached specimens, but the bulk of desmids are usually
attached by their gelatinous secretion to objects that are more or
less stationary, hence the ring-net misses these unless it happens
to brush them off and they find their way into it. The habitats
of desmids also are probably of much greater diversity than the
average microscopist realises, and vary from a roadside ditch
with merely a few inches depth of water in it to a moorland tarn ;
from the wet, moss-grown trunk of a tree to the dripping face
of some perpendicular rock. Last spring in a roadside ditch near
Sidmouth, with barely a quarter of an inch depth of water, was
a perfect film formed of individuals of Closterium Ehrenbergii, in
extremely fine condition. The only way to collect them was to

16 G. T. HARRIS ON THE COLLECTION AND

skim them off the bottom with a spoon, collecting as little mud as
possible in doing so. On another occasion when crossing a boggy
field in East Devon, a small cup-like hollow was noticed filled with
bog water that had a greenish appearance ; on filling a 3 in. by
1 in. tube with the water the colour was found to be due to
Euastrum oblongum in such prodigious numbers as almost to
allow of the term " desmid soup " being applied to the gathering.
These are the " pure gatherings " the authorities refer to. My
fate, however, has usually been to meet them so closely associ-
ated with their environment that the purity of the gathering from
a mounter's point of view has not confirmed the appropriateness
of the term. It is, of course, easy to understand these congested
associations of individuals of one species by reflecting that when
conditions are favourable, and division is actively taking place,
concentration must result unless the water has sufficient motion
to distribute the plants.

Wherever a thin growth of conferva spreads itself on stones in
slow-running streams, or over the surface of submerged woodwork,
desmids may be expected to occur, and the film should be care-
fully removed and bottled. The flocculent matter that collects
around the stems of aquatic plants in ponds and the back-waters
of streams may be collected by Prof. West's trick of clipping
the stem below the surface of the water between the closed fingers
and making of the hollowed hand a cup in which the flocculent
matter is collected by drawing the hand upwards. Masses of
Spirogyra may be lifted out of the water, drained, wrapped in
waterproof paper and deposited in a vasculum ; desmids will
generally be found entangled among their threads and may be re-
moved at home. Mosses from wet tree trunks are best separated
and the stems washed vigorously in a dish, when the desmids, if
present, will be washed away from the moss. Generally speaking,
moss habitats are not prolific hunting-grounds, the species
occurring amongst them being principally those of the genus
Mesotaenium. Swift mountain streams at first sight do not strike
one as likely hunting-grounds, but the confervae attached to
the rocks often contain many good species. My introduction to
the comparatively rare Closterium didymotocum took place at the
head waters of the River Teign on Dartmoor, where it occurred

PRESERVATION OF DESMIDS. 17

somewhat plentifully, growing among tlie algae on the rocks,
and associated with it large numbers of Netrium Digitus. It is
obvious that the ring-net is of little use in such localities ; the
better way is to collect a tuft of algae by hand and wrap it in
waterproof paper or place it in a tube filled with the water in
which it grows.

If the collecting excursion be one of a day's duration only, the
ordinary supply of tubes and bottles will suffice for all the material
likely to be collected, and it may be brought home in the water
in which it was found ; but with an extended excursion away
from home the number of bottles and tubes necessary for several
weeks' collecting would mean a considerable amount of very
careful packing. In addition, to bring home the bottles filled
with the miscellaneous gatherings that are more or less inevitable,
would be to invite certain disaster. Aquatic larvae will intrude
into gatherings of desmids, and when bottled will die, and when
dead will decompose, and the opening of such a collection at home
some weeks later is not a fragrant operation. When planning a
collecting trip of some five or six weeks' duration over Dartmoor
I duly considered these drawbacks and sought some way of
obviating them. After considering and rejecting several methods
I decided to preserve the gatherings on the spot. My object was
to work a certain district of the moor thoroughly, and to keep
the gatherings as far as possible separate. The method I finally
adopted, and which gave me complete satisfaction, was to obtain
material from each bog, moor-pool, etc., and kill and fix the
plants (and incidentally what was with them) on the spot. The
details of this method may be of interest, and possibly of use, to
some of the members.

A small funnel to support the filtering material is essential.
This may be of ebonite, or tin ; glass is inadvisable. For my
own use I make them out of a piece of " ferrotype " metal, cut
to the shape of the collector's net ; three small holes cut in one
side and three metal buttons fixed on the other enable the piece
of metal to be converted at once into a filter support, which un-
buttoned when not required becomes again a flat piece of metal
occupying little space in the collecting-case. After trying many
materials for filtering purposes I found nothing so good as chamois

JouRN. Q. M. C, Series II.— No. 78. 2

18 G. T. HARRIS ON THE COLLECTION AND

leather. Even the filter papers specially made for filtering under
pressure proved useless after a little use. Chamois leather has
the great advantage that it allows of the residue being entirely
removed with a spatula without the risk of tearing it and thus
losing part of the collection. Any material that I have tried
becomes slow in action when thoroughly saturated with water,
and for this reason, if considerable collecting is done during the
day, two, or even three, filters in operation at the same time are
not too many. At least this was my experience when collecting
on Dartmoor. My collecting-case for a day's work contained a
dozen 3 in. by 1 in. tubes, the corks numbered in large numerals
of white paint 1 to 12. Smaller tubes also were carried, and
several 4- ounce wide-mouthed bottles. A blunt- edged knife or
spatula for scraping of! the residue was also carried, and a small
supply of waterproof envelopes, about " court " size, for containing
tufts of algae. The ring-net for bog collecting is indispensable,
but after breaking six tubes in one day's collecting against sub-
merged and hidden stones, I substituted for the glass tube attached
to the net a zinc one. It really is not necessary to examine the
contents with a lens, as it would be quite impossible to make any
useful determination of the smaller species. On arriving at the
bog I propose to work I select a suitable furze or heather bush
contiguous to the bog and support my filter funnels securely in
the topmost twigs so that drainage from the filters is unimpeded.
The bog is now worked with the net and each tubeful collected
transferred to the filters. Tufts of sphagnum may also be col-
lected and the bog water contained in them squeezed into the
filter to extract any desmids growing amongst them. When
sufficient has been collected the residue is drained, then scraped
off the chamois leather with the spatula and transferred to one
of the numbered tubes ; the name of the bog and whatever details
are deemed necessary being entered against a corresponding
number in a notebook. After the residue has been placed in
the tube, clear bog water is added and about 4 c.c. (for a 3 in. by
1 in. tube) of the following killing and fixing solution :

Cupric sulphate (10-per-cent. solution) . . . 100 c.c.

Mercuric chloride (saturated solution) ... 10 c.c.

Exactitude in the amount of preservative added is unnecessary,

PRESERVATION OF DESMIBS. 19

and a little practice soon enables one to estimate about tbe rigbt
amount. In connection with this method of filtering in the field
I have one more accessory to mention which may appear trivial
to those unaccustomed to moorland collecting. This takes the
form of a light wand about 6 feet in length, which is stuck in the
bushes containing the filters ; a hazel stem cut from the hedge-
row on the way answers every purpose. The object is to enable
one to find the filters readily when collecting operations lead one
unconsciously some distance away. It may appear unnecessary,
and I do not insist on it ; but one morning on Dartmoor when
working a somewhat extensive bog it took me an hour's diligent
searching to find the heather bush containing my filters, which
were eventually found on quite the opposite side of the bog from
the one about which I had been searching. Several collecting
articles I have never found, owing largely to the similarity in
appearance among heather bushes when dotted about extensive
moors.

As regards the results obtained by the collecting method just
described, when I state that from about 10 c.c. of material taken
from one small unimportant bog I obtained over one hundred
species and varieties it will be seen that it is a very practical and
productive method. From large, old-established bogs the result
in individuals and species is really very remarkable, and from the
collections made during a summer excursion on the north-eastern
part of Dartmoor I have obtained four hundred species and
varieties, and have still a large quantity of material remaining
unexamined. For the benefit of those unaccustomed to moor-
land collecting a warning may be given as to the character of the
bog. If a collecting excursion were made to a moor like Dart-
moor in late spring or early summer a good deal of disappoint-
ment might be experienced from working impermanent bogs.
These form during the winter seasons, and as summer advances
dry up. The collecting in them is seldom remunerative. It is
the old, deep and permanent bogs that yield the best collections^
and one of the tests that I apply to a bog is the presence or absence
of Sphagnum cuspidatum, this species rarely occurring in any but
permanent bogs. Moorland pools are always w^orth the col-
lector's attention, and often yield quite different species from

20 G. T. HARRIS ON THE COLLECTION AND

those of the bogs. A feature that strikes one in connection with
them is that they are often occupied almost exclusively by one,
or at least a very few, species. One moorland pool I examined
on Dartmoor was so filled with Staurastrum hrachiatum that
from every part of it the net was crowded with specimens, and
another small pool was quite green with the rod-like threads of
Hyaloiheca dissiliens, and practically nothing else occurred there.
Yet another pool was the exclusive preserve of Xanthidium
variahile.

It is obvious that by adopting this method of collecting, bottles
might be altogether dispensed with, the residue of the filtering
being saturated with the preservative, drained and wrapped in
waterproof paper. This would be a very convenient method for
anyone wishing to cover a considerable district during a holiday
without being encumbered with storing appliances.

One drawback is associated with the material collected in the
manner just described ; it is so concentrated, and is such a
heterogeneous mass, that when it comes to mounting the desmids
contained in it the difficulty of isolating them from the debris
of sphagnum, the aquatic larvae, rotifers, entomostraca and a
multitude of denizens that constitute a bog fauna, the mounter
may be excused if he loses patience with such material. Unfor-
tunately I have no remedy to oiler, in spite of the many endeavours
to devise some method which should, even partially, separate the
desmids from their surroundings. The best method I can suggest,
and the one I myself use, is to take a small portion of the material
in a pipette, place it in a shallow tray and well dilute it with water ;
then with a very fine pipette the desmids can be picked out with
a minimum of bog debris. They are transferred to a watch-glass
containing clear water, and if necessary to a second and a third,
obtaining clean desmids eventually by a process of elimination-
Of course the gelatinous secretion of desmids would in any case
make perfectly clean mounts very difficult to achieve.

Mounting desmids is admittedly both a tedious and an uncer-
tain process. I have used practically all the formulae I could
find for mounting media, and however divergent the formulae^
in one particular they all agreed, the chloroplasts sooner or later
were distorted in shape. I quite soon formed the opinion (hetero-

, PRESERVATION OF DESMIDS. 21

dox, I fear) that to seek success by mounting a desmid in a preser-
vative many times denser than its natural medium was a some-
what fatuous quest ; also I saw no reason why desmids should be
exempt from another laboratory process, that of killing and fixing.
After trying several agents prescribed by the textbooks for fixing
vegetable structures, I adopted Hermann's platino-aceto-osmic
solution with very satisfactory results. It fixes and preserves
the histological elements in an admirable manner, and at the
present time there is no shrinkage or alteration of form in some
mounted eighteen months ago. There is, naturally, a little altera-
tion in colour, the chlorophyll becoming browner, but very much
less so than when osmic acid itself is used. Personally, as long
as the histological elements are well preserved I do not attach
much importance to alteration of colour. A few drops of Her-
mann's solution are added to the desmids in half a watch-glass
of water, and allowed to act for two or three minutes, then the
desmids are transferred with a pipette to fresh water two or three
times and washed, and are finally mounted in a saturated solution
of thymol. This is merely distilled water which has taken up as
much thymol as it will dissolve. With this fixing agent I have
been able to get perfectly satisfactory mounts of Netrium Digitus,
which appears to be a very difficult desmid to obtain well fixed,
its chloroplasts becoming distorted and the cell contents contract-
ing on the least interference with it. Hoping to avoid the tedious-
ness of fixing and washing, w^ith the almost inevitable loss of speci-
mens when transferring from one watch-glass to another, for a
short period I mounted the desmids straight away into IJ-per-
cent. formalin. Most of the slides then mounted became useless
from one cause and another — in some species the colour bleached
quite out, in other species the histological elements broke up ; so I
decided that formalin was useless, except perhaps for a few robust
species. Ripart's solution of copper acetate and chloride, which
at one time I used extensively, is another excellent fixing and pre-
serving agent, and the colour of some species is well preserved by
it. A few drops added to the desmids in half a watch-glassful
of water seems to be sufficient.

So much insistence has been laid by mounters on preserving
the green colour of desmids, and the formulae published for

22 G. T. HARRIS ON THE COLLECTION AND

mounting fluids so obviously have this end in view, that it was
only a matter of time for my resistance to break down and com-
mit me also to the quest of a formula that should achieve this
desirable end. I have already stated my indifference to the
preservation of colour so long as the cell contents remained un-
altered. The colour if lost or degraded can always be simulated
by interposing between the slide and radiant a green filter, which
really satisfies the colour sense almost as well as having it in the
desmid. At the same time it is somewhat of a tour de force if
the colour can be retained without sacrificing essentials in cell
structure. To fix and preserve histological detail in desmids is
undoubtedly far easier than to preserve their colour. Chloride
of gold, which is a most delicate and admirable fixative for des-
mids, stains the cell contents blue, but leaves them in perfect
condition for study. Osmic acid by itself colours them deep
brown, unless cleared by hydrogen peroxide ; Hermann's solu-
tion destroys some of the blue in the green of the chlorophyll,
leaving it rather yellow-green. In some species, Closterium cos-
latum, Closterium striolatum, and others naturally somewhat
yellow, the alteration in colour is negligible. The most promising
results as regards combined fixing and colour preservation were
got when I adopted the method of collecting already described.
Desmids collected and preserved by that method nearly twelve
months ago have retained their natural colour although killed
and fixed. This, I am aware, is not a period of time suggestive
of indefinite permanence, it is merely promising. When one has
seen the colour of mounted desmids disappear utterly in about
ten days, twelve months is, naturally, gratifying. I have always
found Micrasterias rotata to be a most impossible desmid to pre-
serve the colour of, and the only time I have approached success
with it has been when collecting and preserving it on the spot.
As it grows readily in a small tank I have usually a good supply
of healthy individuals upon which to experiment, and have done
so rather extensively. With IJ- per- cent, formalin the colour of
this species fades completely in two days, and even when mounted
in such a mild preservative as thymol water the colour gradually
disappears. Hence I look upon the fact of this species having
kept its colour for upwards of twelve months as promising useful

PRESERVATION OF DESMIDS. 23

results. When a large number of species from various genera are
collected and preserved at the same time and in the same medium
it enables one to make very useful comparisons, and I have prob-
ably learnt more with regard to colour preservation from looking
over the preserved material than from numerous, and I fear some-
what empirical, experiments. The following observations on
the present condition of desmids refer to material collected about
nine months ago and preserved on the spot. The species of the
genus Closterium keep both detail and colour remarkably well in
the preserving solution already given, with the exception of
Closterium Ehrenbergii, with which I have never been very suc-
cessful ; the colour is preserved excellently, but considerable
contraction of the endochrome takes place. The Euastra also
seem to retain their colour well. Species of Micrasterias are un-
certain. Micrasterias oscitans preserves excellently unless the
plants are aged. I have already alluded to the difficulty of fixing
Netrium Digitus satisfactorily, and it is rather a curious fact that
in the copper preservative solution the green of the chlorophyll
in this species nearly always turns some shade of red. It is, how-
ever, in specimens I have collected rarely a deep-green colour,
more often quite yellow-green. The filamentous genera, such as
Hyalotheca, and Desmidium, preserve excellently, both colour
and form. One of the species I have hitherto failed utterly with
is the beautiful Spirotaenia bispiralis. It is quite unrecognisable
a few weeks after placing it in the preservative. A fixing agent
of the nature of Hermann's solution might, however, effect its pre-
servation, but of course at the sacrifice of its delicate colour. I
gathered it frequently on Dartmoor in considerable numbers, but
have never come across a single specimen when looking over the
material, so I conclude that the fixing agent was unsuited to it.
The larger species of Cosmarium, Cosmarium Brehissonii, Cos-
marium Ralfsii, Cosmarium fyramidatum, etc., are generally well
preserved. The larger Staurastra also make good mounts, more
especially Staurastrum tumidum. Netrium interrwptum keeps
its fine colour magnificently, then flouts one by its endochrome
assuming the appearance of a pneumatic tyre with a puncture.
Tetmemorus Brehissonii is almost invariably finely preserved, and
its colour unimpaired ; in fact all the species of Tetmemorus

24 G. T. HARRIS ON THE COLLECTION AND

keep well. The fine species Xanthidium armatum turns rather
yellow-green when old cells are mounted.

On one point I have no doubt whatever, which is, that it is of
very considerable importance to store the desmids in the water in
which they are found growing, and I am quite prepared to admit
that the colour preservation in my specimens may be due as
much to this fact as to the particular preserving agent used. Bogs
are usually massed with sphagnum of one species and another,
and it has been stated that the sphagnol present in them is a
powerful antiseptic. If this is so, and if sphagnol is soluble in
water, it might be possible to dispense with a preserving agent
and rely on bog water pure and simple. However, I do not advise
anyone risking their material by relying altogether on the anti-
septic properties of " sphagnol," as I am quite certain that the
aquatic life generally captured with the desmids would have the
last word. In support of the sphagnol theory, however, it is a fact
that the zone of decayed matter in a bog is in a very different
condition from the floor of a weed-grown pond. It is unpleasant
of course to plunge into a bog over one's knees and emerge coated
with brown slime, but at least one is spared the unmistakable
bouquet that such an experience in a pond would entail.

The fact that some individuals in the same gathering and
preservative retain their colour, while the colour of others has
deteriorated, is due most likely to the age of the plant, and prob-
ably also to some pathological condition of the cell. Naturally,
the most vigorous plants would be the better preserved, and it
only remains when mounting to pick out those that seem to be
deeper in colour than the others. This is very noticeable in
Micr aster ias rotata, where some individuals may be deep green and
congested with chlorophyll granules, while others are extremely
pale and semi-transparent — in other words, probably decaying
plants.

The fluid in which the desmids are mounted is sipiply the bog
water to which the preservative was added at the bog side. Usually
when filling up the tubes and bottles a certain amount of the fluid
is superfluous. On reaching home this supernatant clear portion
in each bottle is laid under contribution to accumulate a stock
solution, which is filtered and forms the mounting fluid. It will

PRESfiEVATION OF DESMJDS. 25

be seen that the desmids are mounted in their own bog water,
plus a small proportion of fixing agent ; and if " sphagnol "
is a laboratory fact they also have whatever benefit it confers.
As far as the preservation of the green colour of the plant is con-
cerned, nothing that I have tried- has given me such good results,
but twelve months is far too short a period to be a satisfactory test,
and it may be that this method also will be merely a contribution
to the melancholy collection of unreliable formulae.

One hint I may give to intending mounters of desmids which
I have learned in the very practical school of experience ; it is, to
avoid the use of too shallow a cell for mounting them in. As a
good number of species require the use of fairly high powers, there
is the temptation towards the use of very shallow cells ; at least
this was so in my own case, and the result has been that although
the cells were carefully sealed the extremely small amount of
fluid has evaporated or been absorbed, and many slides made at
great trouble are now finding their way to the waste box. Deeper
cells containing the larger species and an appreciable amount of
fluid seem exempt from this trouble.

I cannot conclude these hints on collecting and mounting des-
mids without allowing myself the reflection that it is unlikely
that a systematic student of the Desmidiaceae will spare the time
necessary for making slides of these plants. The amount of time
involved in getting even fairly decent slides of the various species
is very great, and it is a question if mounted specimens are of
much value to the student. Specific determination of the bulk of
desmids can only be satisfactorily made by studying them in
three aspects, and unless a cell of considerable depth were used
this could not be ensured. A former president of the Quekett
Microscopical Club asserted that the best record of a desmid was
obtained " by the free use of camera lucida," and I imagine that
this dictum has to be accepted even now. Moreover, however
attractive specimens may be which retain their life-like appearance
when mounted, the fact that the cell wall cannot be adequately
studied when the cell is filled with its endochrome seriously dis-
counts the value of a mounted specimen. Identifying specimens
in the genus Cosmarium is almost impossible unless the empty cell
can be obtained, and the same may be said of a large number of

26 G. T. HARRIS ON DESMIDS.

species in the genus Closterium. Penium spirostriolatum is
really only interesting when the empty cell can be procured.

It may appear somewhat paradoxical, while holding the view
that the interest of a mounted desmid is really very limited, that I
should ask the Club to accept for its Cabinet a small collection
of mounted desmids. The reason is, I hope, sufficiently obvious.
Many microscopists without becoming serious students of a group
are sufficiently interested in it to desire an acquaintance with its
principal forms. Further, the variety of species obtainable in the
collecting districts around London has no comparison with those
to be got from alpine and sub-alpine situations, so that species of
very considerable interest may never come in the way of the
metropolitan collector unless he sees them as mounted slides. My
only hope is that some measure of useful life may be granted to
the small collection of slides I ask the Club to accept.

Journ. Qwkett Microscopical Club, Ser. 2, Vol, JIII,, iVo. 78, April 1916.

27

THE PRESIDENT'S ADDRESS.
SOME FACTORS OF EVOLUTION IN SPONGES.

By Arthur Dendy, D.Sc, F.R.S.

Professor of Zoology in the University of London.
{Delivered February 22nd, 1916.)

There is, I believe, at the present day, an unfortunate tendency
on the part of a certain school of biologists to underrate the
importance of systematic zoology as compared with other
branches of biological investigation. Professor Bateson, indeed,
has expressed the opinion * that biologists in general " have
abandoned systematics altogether," but our estimate of the cor-
rectness of this assertion must obviously depend upon how we
choose to define the term "biologist." Some of us think that the
science of biology includes the study of the whole of the organic
world in all its aspects, and that the systematic description and
arrangement of plants and animals constitutes an indispensable
part of the foundation upon which all biological theory must
be based. Indeed, I would go further, and even say that no
biologist without some considerable experience of systematic
zoology or botany is really competent to form a judgment on
such problems as the nature and origin of species and varieties.
I have, it is true, little sympathy with the systematist whose
sole object is to name his specimens and put them away on the
appropriate shelves in his museum, in the hope, perhaps, of
ultimately gathering together a larger collection of " species "
than his neighbour. The labours of such a one, except in so far
as they may afford material for the investigations of those who
are better able to make use of it, hardly rise above the level
of the efforts of the schoolboy who amuses himself by collecting
tradesmen's labels. Such a man, indeed, has no right tO call

* Problems of Genetics, 1913, p. 10,

28 THE President's address.

himself a biologist, for his work is barren and soulless. The
true systematist, on the other hand, is just as much inspired
with the enthusiasm of research and the thirst for knowledge as
the experimental biologist. The difference between the two
lies in the fact that the experimental biologist confines his
attention to the solution of certain fixed and definite problems
suggested by his own very limited knowledge of the organic
world, while the systematist studies the results of the infinitely
varied experiments which Nature has been performing upon
living organisms ever since they first appeared upon our planet.
The experimenter has undoubtedly the advantage of limiting
his problems so that they become more or less manageable and
of performing his experiments under more or less accurately
known conditions, but, on the other hand, there are many
problems with which he cannot deal at all and the solution of
which is no whit less important than that of the problems to
which he is obliged to restrict himself. Evolution is slow, but
human life is short, and slow changes may well be taking place
which we have no means of detecting by means of experiment or
direct observation.

Professor Sollas has estimated the time actually occupied in the
evolution of the modern horse from its remote ancestor Eohippus
at some five or six millions of years. During this period the horse
has increased in height by 53 inches, or, allowing five years for
each generation, at an average rate of 0*00005 inch per genera-
tion. This is a rate of change which, supposing it to have taken
place gradually and not by a series of jumps, we could not hope
to detect by direct observation of living horses, especially when
we remember the fluctuations which must be occurring all the
while. Nevertheless it has led to extremely important results
in the course of time. The experimenter, again, could hardly
hope to observe the transitions by which a normal limb-bearing
lizard might pass into a limbless form such as the blind-worm.
The systematist, however, knows that in both cases intermediate
forms occur and is quite satisfied that, whether gradually or
otherwise, the transitions have actually taken place.

There are, in short, many evolutionary problems which the
e:sq)erimentalist cannot touch but which t*he systematist may

THE president's ADDRESS. 29

fairly hope to solve, just as there are many with which the
experimentalist alone is capable of dealing. Both branches of
biological investigation are essential to satisfactory progress, and
it is in large measure the failure to recognise this fact that has
led to the one-sided and apparently contradictory views on the
subject of evolution that are so prevalent to-day.

Take, for example, the strongly contrasted opinions of
Darwin and de Vries with regard to the origin of species and,
indeed, with regard to evolution in general. Darwin, as is well
known, laid the chief stress upon what he called slow, successive
variations, accumulating in definite directions under the influ-
ence of natural selection. De Vries, on the other hand, con-
siders that species originate suddenly, in apparently spontaneous
variations of an abrupt character, or, as he terms them, mutations.

Now it is very easy to observe the occurrence of mutations,
or even to cause them to appear experimentally, as Tower has
shown in the case of the potato-beetle. On the other hand it
is impossible, owing to the extreme slowness with which the
necessary changes take place, to demonstrate the actual tran-
sition of one species into another by slow, successive, or, as we
now call them, fluctuating variations. Breeding experiments with
regard to mutations give positive results, with regard to fluctua-
ting variations they will probably give negative results, but that
does not prove that fluctuating variations have played no part in
evolution. We must seek other evidence on this point, and that
other evidence is supplied by the labours of the systematist.

The most convincing instance of the part played by slow,
successive variation in the production of new species with which
I am acquainted is that of the flightless birds on oceanic islands.
All zoologists are agreed that these birds are the descendants of
ancestors which reached the islands in question by flying, and
which must, consequently, have had well-developed wings.
The loss of the power of flight can only be explained as due to the
disuse and consequent degeneration of the wings, flight being no
longer necessary as a means of escape from enemies. Now
degeneration, resulting from disuse, appears to be a gradual
process and, so far as I know, never takes place by mutation.
Yet this process, continued for many generations, has resulted

30 THE PRESIDENT S ADDRESS.

in the evolution of such remarkable forms as the extinct moa, in
which the wings had completely disappeared, and the surviving
kiwi, in which they have become reduced to mere vestiges. This
case is greatly strengthened by the fact that precisely the same
result has been arrived at by many birds belonging to quite
different families and in many widely separated islands. In
all these instances the same causes have, as was to be expected,
produced the same effect, and there is not the slightest ground
for supposing that mutation has had anything to do with the
matter. At the same time no zoologist would dream of main-
taining that the flightless kakapo, for example, is not specifically
distinct from the flying parrot from which it must have originated.
We can hardly believe that such species have arisen otherwise
than by slow, successive variation.

I propose to-night, however, to seek evidence from the syste-
matic investigation of a very different group of animals.

There is perhaps no phylum in the animal kingdom that can be
compared with the Sponges as regards the remarkable evolu-
tionary series exhibited by still surviving forms. I have already
dealt with one aspect of this phenomenon in a previous presidential
address, in which I had something to say about the evolutionary
series met with in the siliceous spicules of the Tetraxonida.
You will remember that in this group all the manifold forms
of spicule that occur can be derived from one and the same
fundamental type — the primitive tetract, with its four rays
diverging at equal angles from a common centre. By enlarge-
ment, diminution, branching, fusion, bending and so forth, of
one or more of the original rays, and sometimes by complete
suppression and sometimes by multiplication of rays, an endless
diversity of form has been produced, and the difl'erent forms
for the most part can be arranged in beautifully graduated series.
The same is true, to a lesser degree, of the other group of
siliceous sponges, the Hexactinellida, and also of the Calcarea,
in which the spicules are composed of carbonate of lime. Again,
in the case of the true horny sponges, or Euceratosa, we find a
beautiful evolutionary series leading up from the simply branched,
tree-like skeleton of Aplysilla to the complex reticulate skeleton
of the bath sponge.

THE president's ADDRESS. 31

If you ask wliat justification we have for arranging the series
as we do and for assuming that they represent actual stages
in evolution, I can only reply that we have exactly the same
justification as in the case of any other group of organisms.
Where we find a graduated series leading from simple to com-
plex it is difficult to account for it on any other hypothesis, especi-
ally when, as is actually the case in sponges, the various stages
exhibited by one system of organs are correlated with correspond-
ing stages exhibited by other systems. Thus in the tetraxonid
sponges the evolution of spicular form is accompanied by evolu-
tion in the arrangement of the skeleton as a whole and also in the
arrangement of the canal-system, and again in the Euceratosa
the correlation between the degree of complexity attained by
the skeleton and that attained by the canal-system is very striking.
Moreover we can, in some cases, appeal to the facts of ontogeny
or individual development. One of the most highly modified
forms of spicule found in tetraxonid sponges is the discotriaene
of the genus Discodermia. This spicule resembles nothing so
much as a carpet nail, the disc being formed by three of the rays
of the primitive tetract form expanded and fused together,
as is shown conclusively by the fact that the young spicule
passes through a stage in its development in which all three
rays are separate and it is, in short, an ordinary tetract. Plenty
of awialogous cases could be mentioned, and many more will
doubtless be brought to light as our knowledge of the subject
increases.

Palaeontological evidence, unfortunately, teaches us but little
with regard to the evolution of sponges, for most of the fossils
known are highly specialised forms which owe their preservation
to the peculiar manner in which the spicules have become
united together in a coherent framework. For some unknown
reason, however, it appears that most of the evolutionary stages
through which recent sponges have passed are still represented
by existing forms, and that is why the group is so exceptionally
suitable for the study of evolutionary processes.

When we come to consider the factors involved in the pro-
duction of these evolutionary series we have to note in the first
place that we can distinguish between two types of modifications —

3^ THE president's ADDRESg.

those which are obviously adaptive in character and those which
seem to have no sort of relation to the requirements of the
organism in which they occur. This point is very well illus-
trated by the form and arrangement of the spicules.

It is obvious that spicules, being secreted by the living pro-
toplasm of mother-cells or scleroblasts, can only make their
appearance in situations where such cells occur — that is to say,
speaking generally, the mesogloea or middle layer of the sponge-
wall. Hence, in the simplest calcareous sponges, of the genus
Leucosolenia, where the entire body consists of a single thin-
walled tube, we find the skeleton composed chiefly of a system
of triradiate spicules lying in the middle layer of the wall, where
their interlacing rays form a kind of lattice-work. In the inter-
vals of this lattice-work lie the inhalant pores or prosopyles,
and the form of the triradiate spicule is obviously related
to the arrangement of these apertures in the wall of the tube,
the rays being extended in the intervals between the pores
and, at the same time, where necessary, becoming curved so
as to follow the curvature of the wall of the tube. The ar-
rangement of the skeleton as a whole, then, and the form of
the principal spicules alike appear to be determined in the
first instance by the arrangement of the canal-system and to
be due to easily understood mechanical causes. Even in such
simple forms as Leucosolenia, however, we usually find two
further adaptive modifications of the skeleton. Some of the
triradiate spicules may develop a fourth or " apical " ray,
which springs from the centre of the spicule and projects
into the cavity of the tube (gastral cavity), where it serves as
a protection against internal parasites. A corresponding protec-
tion of the external surface is effected in a different manner, by
the development of a monaxon spicule pointed at both ends,
arranged so that one end projects obliquely outwards and up-
wards, giving a prickly or sometimes hairy character to the
surface. The relations of the monaxon form to the triradiate are
somewhat obscure, but we know from the researches of our late
President, Professor Minchin, that the triradiate of the calcareous
sponges is not a simple spicule but a spicule-system, formed
by the union of three monaxons each initiated by a separate

THE president's address. 33

mother-cell, and that the apical ray of the quadriradiate is
another unit added to the system by yet another mother-cell.
It is difficult to explain the origin of the monaxon and quadri-
radiate spicules, but it seems quite possible that each arose as
a mutation, which, proving advantageous to the sponge, was
fostered by natural selection.

If time permitted it would be easy to show you in detail how,
from this simple type of skeleton, various adaptive modifications,
the nature of which has been determined largely by mechanical
requirements, have led up to the far more complex skeleton in
each of the higher families of Calcarea, but we must content
ourselves with only a few of the numerous interesting facts that
recent researches have brought to light. It is clear that the
arrangement of the skeleton must always be conditioned to a
great extent by that of the canal-system, and, at first at any
rate, the canal-system has certainly led the way. Progressive
evolution has been brought about in this case by those processes
of colony-formation and integration to which I referred in my
last presidential address. Radial budding from the simple
tubular body of a primitive Leucosolenia gives rise to the
Sycon type, in which the collared cells that originally lined
the whole of the gastral cavity become restricted to the radial
tubes or chambers. The skeleton of the central tube becomes
more or less specialised to form the gastral cortex. In the walls
of the radial chambers the triradiate spicules take on a more
definite orientation. One ray becomes elongated and directed
towards the distal end of the chamber, and the other two tend to
surround the chamber, with the angle between them facing the
opening into the central cavity. The entire spicule thus becomes
" sagittal," with differentiated basal and oral rays, and inas-
much as the oral rays tend to form a series of rings around the
chamber the arrangement of this part of the skeleton is said
to be articulate. The monaxon spicules are confined to the
blind end of the chamber, where they form a projecting tuft, and
as all the ends of the chambers lie at approximately the same
level a new dermal surface is formed, protected by the projecting
monaxons.
In the meantime the walls of adjacent radial chambers come
JouRN. Q. M. C, Series II.— No. 78. 3

34 THE president's address.

into contact with one another more or less throughout their
length and fusion takes place. Thus the originally continuous
system of interspaces between these chambers becomes broken
up into more or less sharply defined intercanals, or inhalant
canals, through which water gains access to the prosopyles
in the chamber walls. The openings of these inhalant canals
appear as gaps between the blind distal ends of the radial
chambers.

The next important stage in the evolution of these sponges
is the development of a dermal cortex, and it is not difficult
to see how this has taken place. We find the beginning of the
process in some species of Sycon, in which the external opening
of each inhalant canal becomes covered over by a delicate
membrane pierced by secondary inhalant pores, or dermal
pores, analogous to the prosopyles in the walls of the radial
chambers but quite different in their mode of origin. This dermal
membrane is an entirely new development, but it has evidently
been formed in a very simple manner by extension of the outer
layer of the walls of the radial tubes. It is at first very thin
and delicate, without any supporting skeleton of its own, and
merely serves as a kind of sieve for filtering the stream of water
as it enters the sponge and perhaps, by appropriate contraction
of the dermal pores, as a means of regulating the rate of flow.
Its appearance, however, gives rise to new possibilities in the
way of skeletal development. These are realised chiefly in the
appearance of a definite cortical skeleton, composed principally
of triradiate spicules arranged tangentially as regards the dermal
surface. The development of such a dermal cortex is charac-
teristic of all the higher families of Calcarea.

With the appearance of both gastral and dermal cortex new
mechanical principles come into play in the formation of the
skeleton. Up to this point the skeleton of each radial chamber,
or tubar skeleton, as it is termed, has been an independent
structure developed in the walls of that chamber and in relation
to that chamber alone. Now, however, that the originally
separate chambers have all become intimately connected together
so as to form, with the dermal and gastral cortex, a kind of
secondary, and of course much thicker, wall to the central gastral

THE president's ADDRESS. 35

cavity, we find that further progress in skeletal development
is determined by the requirements of the wall as a whole, and
no longer by those of the individual radial chambers. We have
here a beautiful example of integration.

In some cases the dermal and gastral cortices become, as it
were, bolted together, across the intervening chamber layer,
by a special system of large subdermal and subgastral spicules,
whose principal rays extend in opposite directions from the dermal
and gastral cortex respectively, so as to interlock with one another
in the chamber layer. At the same time there is a more or less
strongly marked tendency towards reduction of the articulate
tubar skeleton of the individual radial chambers, which is replaced
functionally by the so-called inarticulate type developed in
relation to the sponge-wall as a whole.

The evolution of the inarticulate type of skeleton appears to
have followed a different course in the two families Heteropiidae
and Amphoriscidae. The case of the Heteropiidae is the more
remarkable and forms a very curious illustration of adaptability
to special requirements in both form and arrangement of the
spicules concerned. We have all stages of the process represented
in existing species, and there can, I think, be no doubt as to the
facts of the case, which have been described by my colleague
Mr. Kow and myself in our paper on the Classification and
Phylogeny of the Calcareous Sponges,* nor as to the interpreta-
tion of those facts at which we have arrived. Briefly stated,
the sequence of events has been as follows.

In an ordinary Sycon the blind distal extremities of the radial
chambers are conical in shape and, in conformity with the
curvature of the wall of the chamber, the outwardly directed
basal rays of the most distally situated triradiate spicules
become tilted towards the apex of the cone. One of the paired
oral rays now becomes directed more towards the gastral cortex,
while the other grows away from the chamber-wall into the
newly developed dermal membrane. With the development of
a true dermal cortex the basal ray and the last-mentioned oral
ray both take up their position in this cortex, lying parallel to
the dermal surface, while the first-mentioned oral ray becomes

* P.Z.S., September 1913.

36 THE president's address.

directed vertically inwards towards the gastral cortex and in-
creases greatly in length.

We thus have a complete reorientation of the spicule in ques-
tion, and a new symmetry established as regards its rays. We
have what we term a pseudosagittal spicule, superficially re-
sembling the ordinary sagittal spicule, but in which the indi-
vidual rays do not correspond as they appear to with those of
the latter. The apparently unpaired and very strongly de-
veloped ray (which we may now call the centripetal ray) is one
of the original paired (oral) rays, and one of the apparently
paired rays (which we may now call the outer or dermal rays)
is the original unpaired (basal) ray. The new symmetry never,
so far as we have observed, becomes perfect, for the outer or
dermal rays usually differ from one another in shape. Some-
times one is straight and the other curved, and the straight one
represents the original basal ray. The centripetal ray grows
much longer than the dermal rays and may even reach the
gastral cortex.

In the meantime the sagittal triradiates of the chamber
skeleton which lie nearest to the gastral cortex have become
specialised as subgastral sagittal triradiates. This change
involves little, if anything, more than increase in length of the
centrifugally directed basal rays, which interlock, as already
explained, with the centripetal rays of the subdermal pseudo-
sagittals. By disappearance of the remaining spicules of the
original articulate tubar skeleton the transition to the " inarticu-
late " type is completed.

The second way in which an " inarticulate " type of skeleton
may arise is seen in the Amphoriscidae. Here the subdermal
spicules are quadriradiates, the large centripetal ray being an
apical ray added to an ordinary triradiate whose three facial
rays lie tangentially in the dermal cortex. Obviously such a
skeleton could not arise until the dermal cortex had become
well established. Here, then, we have a beautiful example of
convergent evolution, the same mechanical result being broughr
about in two totally different ways in the two families Heter/
piidae and Amphoriscidae.

It is extremely interesting to observe that after the skeleton

THE president's ADDRESS. 37

has once been adapted in relation to the sponge-wall as a whole
rather than to the individual radial chambers, the canal-system
may undergo further evolution without affecting the skeleton
arrangement. This is true not only of the Heteropiidae and
Amphoriscidae, but also of the Grantiidae, In all these families,
by a complex process of folding of the chamber-layer as a whole,
sometimes accompanied by branching of the chambers them-
selves and reduction in their size, the radial arrangement may
become lost and the well-known transition from the syconoid
to the sylleibid and perhaps even the leuconoid types of canal-
system be effected.

The entire series of skeletal modifications which we have so
far considered are evidently of an adaptive character, suited to
meet the new requirements arising in the course of the evolution
of the sponge as a whole through the processes of colony-
formation and integration. Many other illustrations of the
same type of evolution might be selected from other groups of
sponges. In this connection I may again refer very briefly to
the evolution of tetraxonid siliceous spicules. In this group
we never find a canal-system with elongated flagellate chambers
arranged radially around a central gastral cavity, and the
siliceous skeleton does not seem to have made its appearance at
all until the canal-system had reached a stage corresponding to
the most advanced type of arrangement met with amongst the
Calcarea, with numerous small spherical chambers scattered
through the thickness of the sponge-wall and a branching system
of inhalant and exhalant lacunae. It has been supposed that
the primitive tetraxon spicules were originally developed in
the three-dimensional intervals between the chambers, just as
I have suggested that the primitive triradiates of the Calcarea
were developed in relation to the two-dimensional intervals
between the prosopyles of a primitive Leucosolenia. However
that may be, the primitive skeleton of scattered tetracts appears
to have given rise along various lines of evolution to an immense
variety of skeletal types both as regards spicule form and spicule
arrangement. Many of these types are as clearly adaptive in
character as in the Calcarea. I need only mention such cases
as the development of triaenes and their specialisation for

38 THE president's address.

various different purposes, such as the protection of the dermal
surface by discotriaenes and the anchoring of sponges which
live on a muddy bottom by means of " grapnel spicules."

As regards such adaptive modifications it really seems as if
the sponge were able to do anything that may be required with
the inherited material at its disposal, to convert a calthrops into
a pitchfork, a grapnel or an armour plate as occasion demands.

There are, however, as I have pointed out to you before, other
series of skeletal modifications which seem to have no adaptive
significance whatever. These are perhaps best seen in the
extraordinary forms assumed by so many of the microscleres in
the Tetraxonida, all of which may be derived, through more
or less complete series of known intermediates, from the primi-
tive tetract. It is quite impossible, for example, to assign any
useful purpose to those extraordinary and singularly beautiful
spicules which we call chelae, so characteristic of the family
Desmacidonidae. Yet these chelae exhibit such definite and
constant forms, and at the same time occur under so many
different modifications, that they afford some of the most
useful criteria of specific distinction in this group. The reason
for the existence of their divers modifications is at present
a complete mystery to us ; we can only say that they must
be, to use a mathematical expression, functions of heritable
modifications in the constitution of the protoplasm of the
germ-cells, the nature of which is as yet beyond reach of
investigation, and that they are perhaps correlated with other
characters which are of real value to the sponge.* It seems
to me probable that they originate in most, if not in all, cases
as mutations, for they seem to be just the sort of characters
that are known to originate in this way in other groups of
the animal kingdom ; but there is, I think, better evidence
of the occurrence of mutations in sponges, though unfortunately
it is as yet impossible to put the matter to the test of breeding
experiments.

In attempting to draw up a scheme of classification, whether
it be of the Calcarea or of the Tetraxonida, we find certain very

* Cf. my previous address on "By-Product j of Organic Evolution,"
Journ. Q.M.C., vol. xii. p. 05.

THE president's ADDRESS. 39

well marked characters appearing again and again, in a sporadic
fashion, in widely separated groups, and it is impossible to
arrange our material in such a way that this shall not take
place. I do not, of course, refer to cases of convergence due to
adaptation to similar conditions of life, which are common
enough in sponges as in other animals. The characters in ques-
tion are again evidently non-adaptive. Take, for example, the
distribution of what are termed trichodragmata amongst the
Tetraxonida. The trichodragma is a bundle of short, hair-like
spicules, apparently all originating in one and the same mother-
cell. They occur scattered through the soft tissues of the sponge
without any relation to other structures, and it is impossible, at
any rate in the present state of our knowledge, to assign to them
any useful function. They sometimes occur in a whole group of
evidently closely related species and have in several cases been
used as the chief distinguishing character of genera. In the
genus Cinachyra, on the other hand, they occur in only a single
one of the twenty species recognised. They occur, again, in
such widely separated families as Stellettidae, Tetillidae and
Desmacidonidae, and, wherever they are met with, they exhibit
an extraordinary uniformity of structure. A precisely similar
phenomenon is observable in the case of the small monaxon
spicules known as microxea amongst the Calcarea.

Now we know that mutations are discontinuous in their mode
of origin and that the same mutation may occur again and
again. Discontinuity in the present distribution of trichodrag-
mata and microxea almost certainly implies discontinuity in
origin. Probably these spicules have arisen suddenly, and on
many occasions, as the result of some unknown change in the
constitution of the germ-plasm. It is, no doubt, more a
chemico-physical than a biological phenomenon, and that, I
believe, is true of all mutations.

Let us now consider briefly some examples of what are prob-
ably to be interpreted as mutations in the case of megascleres.
It is well known that derivatives of the primitive tetract not
infrequently exhibit meristic variations as regards the number
of their rays. It is very doubtful whether all of these can be
regarded as mutations, for in many cases we find great varia-

40 THE president's ADDRESS.

tion in the degree of degeneration of individual rays. I have
recently, however, come across a case — not, indeed, unique —
in which I think the variation in the number of rays must
have originated discontinuously, or in other words, by mutation
One of the most characteristic spicules in the genus Tetilla is
the anatriaene or grapnel spicule, a modified tetract which
usually has a very long, slender shaft and three short,
recurved, hook-like cladi. In Tetilla pilula, although the
entire sponge is very small, there are probably some thousands
of these grapnel spicules in a single specimen, but they are
not typical grapnels, for in every case observed only a single
cladus is developed, the other two have disappeared, without
leaving the slightest vestige to indicate their former presence.
Only three specimens of this sponge are known, but all agree
in this peculiarity, the anatriaene has become an anamonaene.
Another form of triaene, the protriaene or pitchfork, occurs in
the same species, and these retain the full number of cladi.

In the closely related genus Cinachyra similar triaenes occur,
and in a species which I have recently been investigating and
shall shortly describe under the name Cinachyra vaccinata, three
kinds are found, ana triaenes and large and small protriaenes, and
all exhibit a striking peculiarity in that the apex of the shaft,
which in other species tapers to a fine point, is conspicuously
enlarged like a handle. I have two specimens, each containing
an enormous number of these spicules, and I have seen no excep-
tion to this rule.

One more illustration must suffice. Species of the genus
Esperella (Mycale) possess a somewhat varied assortment of
spicules. The typical megasclere is a style, with rounded or
enlarged base and evenly pointed apex. Amongst the micro-
scleres occurs the widely distributed sigma, a C-shaped or S-shaped
hook, pointed at each end. In the closely related genus
Paresperella the back of the hook, just where it curves round
at each end, is provided with teeth like a saw, and, curiously
enough, in one of the two species which I have examined, the
apex of the style is usually provided with two teeth, and in the
other with one. There seems to be a correlation here between
the modification of the si^ma and that of the style, just as in

THE president's ADDRESS. 41

Cinachyra vaccinata there is a correlation between the modifi-
cations of the three kinds of triaene.

Such variations as these strongly suggest the existence of
definite factors in the germ plasm, upon which the modification
depends. It appears also that in some cases a factor may influence
in the same kind of way the form of more than one type of spicule.
On the other hand, the facts with regard to the meristic varia-
tion of the triaenes suggest that each ray may be influenced by
a separate factor.

The factorial hypothesis appears to be further supported by
certain very definite conclusions at which we are arriving as
to the general course of evolution followed by the Tetrax-
onida. On the whole, evolution seems to have been pro-
gressive, accompanied by increasing complexity of structure,
manifested especially in the skeleton. Along certain lines of
descent, however, it appears that the culminating point has been
passed and regressive evolution has taken place, resulting in
simplification of structure. This simplification seems to have
been effected by the complete dropping out of certain types of
spicule. This is strikingly exemplified by the case of the great
family Stellettidae and its derivatives. The progressive evolu-
tion of the stellettids was marked by a strong development of
triaenes of various kinds, accompanied by a beautiful series of
astrose microscleres, many of which have very remarkable and
easily recognisable forms. In his report on the Tetractinellida of
the Challenger Expedition Professor Sollas proposed the family
Epipolasidae for a number of species which differ from the
stellettids only in the total absence of triaenes. We know now
that this group is not a natural family, but consists of a hetero-
geneous assemblage of stellettids which have independently lost
their triaenes, and in some cases we can tell with certainty, by
the characteristic form of the asters, from what particular stel-
lettid genus an epipolasid species has been derived. We can even
do more than this, for in the genus Aurora there are three per-
fectly distinct triaene-bearing species each with a closely corre-
sponding epipolasid species. The genus Chondrilla, again, ap-
pears to have arisen from^stellettid ancestors by loss of all the
megascleres, and, finally, in Chondrosia, microscleres as well as

42 THE president's address.

megascleres have disappeared, so that these sponges bear a
strong superficial resemblance to the primitive skeletonless
Myxospongida — an excellent example of convergent evolution.

The loss of spicules to which we have been referring cannot
be looked upon as an adaptive modification, nor can we explain
it as due to mechanical necessities. We know of nothing in the
conditions of life to account for it, and can only suppose that
it is due to some change in the germ- plasm affecting the
power of the sponge to produce the particular spicules in
question.

How can we reconcile these facts with the belief that evolution
has taken place, in the main, by slow, successive modifications
rather than by sudden mutations ? The conception of factors is
intimately bound up with that of mutations, and the existence
of the one would seem to imply the occurrence of the other. We
must remember, however, that the modifications which seem to
be due to separate factors are only rarely and accidentally of
value to the organism, so that they hardly ever, in themselves,
lead to progressive evolution, and the fact, if it be a fact, that
progressive evolution is accompanied by an increase in the
number of factors in the germ-plasm is no sort of proof that
the factors themselves are of primary importance in determining
the course of that evolution.

If we look at the progressive evolution of the sponges as a whole
we see that it has been a gradual process of increase in complexity
of structure due to colony formation and integration, in which
branching and budding, folding and secondary fusion, have played
the chief parts, while the skeleton has constantly become adapted
to suit the new mechanical requirements. If, in the course of
this evolution, certain categories of spicules have been influenced,
even to their disappearance, by certain factors in the germ-
plasm, this does not necessarily imply that the evolution of these
spicules in the first instance took place by way of mutation. A
great cathedral may develop slowly and gradually for centuries
under the hands of successive generations of architects and
workmen, and in the end it may be destroyed in a few hours
in consequence of a sudden outbreak of hostilities. Similarly the
loss of characters in living organisms may be due to the appear-

THE president's ADDRESS. ' 43

ance of destructive ratlier than to the disappearance of construc-
tive agents.

We find then, in sponges as in higher groups of animals,
many characters that are obviously adaptive and many others
that appear to have no such significance, and characters of
both categories are used by systematists as indices of genetic
affinity, for the purpose of constructing a natural, phylogenetic
arrangement of the organisms in question.

As to which set of characters is to be regarded as the more
important from the point of view of the student of progressive
evolution there can, I think, be little doubt, but how far the
division into adaptive and non-adaptive corresponds to the dis-
tinction between fluctuating variation and mutation is a different
question. Certainly the chances are greatly against a mutation,
when it first appears, having any adaptive significance. The
apical ray of a calcareous quadriradiate may perhaps arise as a
mutation, at any rate there seems to be no mechanical necessity
for its appearance. It may remain quite short and without
obvious significance for the well-being of the sponge, as in the
dermal quadriradiates of some species of Leucetta, but, in other
cases, it may be seized upon," so to speak, as a new weapon in
the struggle for existence and used as one of the most important
constituents of the skeleton, as in the Amphoriscidae. Many of
the specific characters of the microscleres, again, may have arisen
as mutations, but they seem to have remained entirely meaning-
less from the point of view of function.

It seems to me incredible that the long series of adaptive changes
which have taken place in the evolution, say, of the skeleton of
the higher Calcarea, and which are so closely correlated with
one another and with the evolution of the canal-system, can
have been entirely or even mainly dependent upon the accidental
occurrence of mutations, which are supposed to take place in
all directions and without any relation to the necessities of the
organism. When, for example, the dermal cortex appeared
no doubt scleroblasts wandered into it as is their wont, and there
gave rise to triradiate spicule-systems tangentially arranged.
The whole process is obviously determined chiefly by mechanical
conditions. The establishment of one modification gives oppor-

44 THE president's address.

tunity for tlie occurrence of another, and there is no reason to
suppose that mutation has had anything to do with it beyond
occasionally and accidentally providing the organism with
some new character capable of being developed- into something
of value.

In my opinion the slow, successive variations of the Dar-
winian theory have had far more to do with the evolution of
sponges than the process of mutation, and are mainly respon-
sible, under the guidance of natural selection, for adaptive modifi-
cations.

This is perhaps nowhere better seen than in the root-tufts of
anchoring spicules so characteristic of those species of Tetillidae
that live on muddy sea-bottoms. The starting-point for the
development of such a root-tuft is, of course, provided by the
anatriaenes or grapnel-spicules, whose distal ends, bearing the
three recurved hooks, frequently project beyond the surface
of the sponge. The only thing necessary for the development
of an efficient anchoring tuft is the elongation of the shafts of
those anatriaenes which project from the lower part of the sponge,
and such elongation is exactly what might be expected to take
place as the result of fluctuating variation under the influence
of natural selection. Exactly the same kind of thing is seen
in those curious Trichostemma- and Crinorhiza-forms which
support themselves, parachute-like, on soft ooze by throwing
out a fringe of long spicules or spicule-bundles, radially arranged,
like the ribs of an umbrella. If the intermediate forms happen
to disappear, such characters as these may of course be used
by the systematist for the discrimination of species just as well
as characters that are supposed to arise by mutation.

In my Presidential Address to the Zoological Section of the
British Association for the Advancement of Science, at the
Australian meeting in 1914, I had occasion to observe that " it
seems likely that mutation has had a great deal to do with the
origin of species, though it may have had very little to do with
progressive evolution." My friend Dr. Dixie, in a recent article
in the Church Quarterly Review, seems to regard this statement as
indicative of inconsistency on my part, as I had previously
admitted that mutation might be one of the factors of divergent

THE president's ADDRESS. 45

evolution. He suggests that I should" perhaps seek to reconcile
the statements by insisting on the distinction between ' diver-
gent ' and ' progressive ' evolution." Certainly no such idea
of reconciliation was in my mind. I thought I had made my
position clear in the succeeding paragraph, in which I remarked
that " just as we have learnt to regard individuals as the tempo-
rary offspring of a continuous stream of germ-plasm, so we must
regard species as the somewhat more permanent but nevertheless
temporary offshoots of a continuous line of progressive evolution."
As I have evidently not succeeded in my intention, I may
perhaps be allowed to make a fresh endeavour to relieve myself
of the charge of inconsistency, and to illustrate my meaning once
more from the great storehouse of facts derived from the study
of sponges. A very large number of species in this group are,
as I have already indicated, distinguished from one another by
minute but constant differences in the form of the spicules,
especially of the microscleres, which have no conceivable value
from the point of view of adaptation and have in all probability
arisen as mutations. Such specific characters may be afforded
by the number and form of the teeth on a chela, or by the
ornamentation of some other form of microsclere, which can only
be made out under high powers of the microscope. Characters,
on the other hand, which are obviously adaptive in nature, such
as the arrangement of the skeleton as a whole and its relation
to the canal-system, which seem to have developed, if not to
have originated, by slow, successive variation under the influence
of natural selection, are usually common to many species in the
same genus ; they are not, as a rule, specific characters. Hence,
though species seem frequently to have arisen as mutations in
trivial and non-adaptive characters, evolution on the whole
seems to have taken place by a process of progressive evolution,
in which mutation has played a comparatively small, though
by no means negligible part. In the vast majority of cases a
specific character appears to bear much the same relation to
the organism that exhibits it as the colour of a motor-car bears
to the car itself. The colour has nothing to do with the efficiency
of the car, and plays no part in the evolution of motor-cars, but
^t affords a very convenient means of distinguishing one car from

46 THE president's address.

another. If all cars of the same kind were painted of the same
colour the analogy would of course be more complete.

In conclusion, if any one should ask me how I should propose
to define the term " species " as applied to sponges, I could only
reply that, at any rate in the present state of our knowledge, no
satisfactory definition is possible. In practice we give the name
to any group of individuals that closely resemble one another
and are at the same time distinguishable from any other
group by one or more characters that they possess in common.
Such groups may have arisen in divers ways, as by sudden
mutation or by the dying out of connecting links in the course of
gradual divergent evolution, and it is quite possible that
hybridisation has also played a part. It is more than probable
that many groups now regarded as distinct species will ulti-
mately be found to be connected by more or less perfectly
graduated series of intermediate forms. This probability, how-
ever, has no terrors for the philosophical systematist, for one of
his principal objects is to reconstruct the phylogenetic tree and
demonstrate the genetic relationships of all the members of the
group on which he works, and from this point of view the more
connecting links he discovers the better he will be pleased.
Whether his species are good, bad, or indifferent, is a matter of
secondary importance, though of course every reasonable worker
will avoid as far as possible the unnecessary multiplication of
specific names.

Journ. Quekett Microscopical Club, Ser. 2, Vol. XIII., No. 78, April 19l6i

47

ON THE BDELLOID ROTIFERA OF SOUTH AFRICA.

PAET I.
By W. Milne, M.A., B.Sc, F.E.S.E.

{Read March 28th, 1916.)

Plates 2-6.

The material for this paper lias been gathered intermittently
during the last ten years. A few of the species described are
aquatic, but the large majority are moss-dwellers. The aquatic
species are probably very numerous in South Africa, but little
attention was paid to them.

Only a few meagre lists of South African Bdelloida, with no
description of new species, had been published when in 1911
Murray's Bdelloid Rotifera of South Africa (11) * was issued.
He mentioned fifty-three species as having been found, and
tabulated forty which he had himself seen. Of these forty I
have seen all but seven, and of the other thirteen I have seen ten.

I have been enabled to widen the scope of this paper by the
help of several friends, who provided moss from parts inaccessible
to me, and I have much pleasure in naming species after them.

I have had much correspondence with Mr. Bryce, and feel
greatly indebted to him for assistance freely given. I received
also from Mr. James Murray many helpful suggestions.

Mr. Bryce (6) has done a great service to students of Bdel-
LoiDA in publishing his new classification. He has brought
order out of what was fast becoming chaos. His classification
is an excellent piece of work. I have only one small objection
to make, and that is to a name. Mr. Bryce has proved conclu-
sively that C. elegans (Ehr.) was certainly different from the
short-footed species, which have usually been termed Callidina,
therefore it follows that the genus Callidina, founded on that
species, cannot include the short-footed ones. At one time I

* Note. — The figures in brackets refer to the Bibliography.

48 W. MILNE ON THE

(2) thought C. elegans (Ehr.) was really Adineta. That is prob-
'ably a mistake. At any rate I was satisfied that Callidina (Ehr.)
could not include the short-footed species, and so I constituted
a genus, Macrotrachela, for them. Ehrenberg's genus is not
necessarily done away with.

The definition for Macrotrachela first given still applies, with
an addition rendered necessary owing to Mr. Bryce's removal
of the pellet-makers into a new genus — a thoroughly sound
proceeding — Macrotrachela : — Bdelloida having three toes ;
foot shorter than the pre-intestinal part ; oviparous ; and not
pellet-makers.

I shall in this paper, therefore, place all species which answer
to this definition under the above genus.

Harring (12) has taken the same view with regard to the name
of the genus.

The genus Habrotrocha is growing into a very large and un-
wieldy group, so I have taken this opportunity to separate some,
and place them in a new genus, Otostephanos. They are different
from all the others in that they possess a ring of fair thickness
round the corona, with short breaks ventrally and dorsally.
Murray's H. auriculata (10) which I have known for several years,
is one of them. I have three other species to describe.

In the description of species I generally mention the nature of
the lamella. Some writers consider that there are two separate
lamellae, at least in some species. I have never been able to
make out more than one. There are several undoubted instances
of a single hood-like lamella, without any indentation whatever,
as in H. cucullata (Murray). The common form has a sharp fold
in the middle of the lamella, giving it a double appearance, but
not with two separate parts. There are some which seem to me
to have a double fold, giving in certain positions a triple lamella,
as in P. grandis ; and others with a triple fold giving a quadruple
lamella, as in M. russeola and M. Ehrenbergi. The ear processes
mentioned by Janson (3) as part of the rostral sheath in the
latter, are part of the lamella.

I have made some general remarks on the jaws of Philodina,
which will be found under the description of Monoceros falcatus.

In 1906 my attention was drawn to a small animal, chiefly
through the odd appearance of a bunch of large appendages,

BDELLOID ROTIFERA OF SOUTH AFEICA. 49

posteriorly. It was soon apparent that there were other abnor-
malities about the creature, and that it was so aberrant — although
an undoubted Bdelloid — that it could not be placed in any of the
three families as given in Bryce's classification of the Bdelloid a
I have therefore constituted a new family for this animal :

MoNOCEROTiDAE fam. nov.,

Bdelloida having, on the penultimate segment of the foot,
one spur only.

The MoNOCEROTiDAE differ from all other known Bdelloida
in possessing only one spur. That they are Bdelloids, I think
there can be no doubt. In their habits they resemble Micro-
DiNiDAE and Adinetidae, but on the whole come nearest to
MiCRODiNiDAE ; but the differences are very great. The jaws
in each are abnormal, but not of the same type. The corona is
very meagre in Monocerotidae, but wanting altogether in
MicRODiNiDAE. Both possess four toes, but in Monocerotidae
the toes have each a separate external sheath.

In all other details, not already referred to, there seems to be
no great difference from Bdelloida in general.

MONOCEROS gen. nov. *

Generic Characters. — Having one spur only ; fouEr toes, and a
fully developed rostrum. The corona is inconspicuous or obscure.
Jaws are abnormal.

Two small circular arrangements, with not the slightest
semblance of pedicels, situated on a prone face, represent the
corona in Philodina. The gullet is extremely short.

Monoceros falcatus sp. nov.

PI. 2, figs. l-ld.

Specific Characters. — Rostrum well developed, with strong
cilia. Corona inconspicuous — a sessile rotulate arrangement
bearing rather feeble cilia on the rims and possibly no cilia

* Since the above was in type I have learned that the generic
name Monoceros is already pre-occupied and according to the rules
of nomenclature is ineligible ; this also applies to the ordinal name
as well. It is intended to rectify the error in Part II of this paper.

JouRN. Q. M. C, Series II.— No. 78. 4

50 W. MILNE ON THE

posteriorly. Gullet extremely short. Jaws quite abnormal. A
short tube from the mastax, dorsally, leads into a large stomach
mass. The foot is very stout, and tapers very little — possibly of
four segments. Toes four, sickle-shaped, exceptionally long,
each in its own large sheath. One large spur, dorsally placed ;
broad at the base, curving outwards slightly and then inwards
to a point.

Antenna about as broad as long — with scrubby setae. There
is a large brain mass, situated above and behind the mastax,
branching off anteriorly into the antenna and forward, apparently
into the rostrum. Intestine large, and contractile vesicle not
very conspicuous. Foot glands are large. Size, l/120th inch.

Monoceros falcatus is quite small and of a pale glaucous colour.
The most striking feature is the posterior of the foot, with its
four great sickle-shaped toes and the large spur ; looking, when
all planted downwards, as if supported on a banana-like bunch
of props. I should probably have overlooked the first specimen
had it not been for this odd appearance. The extended toes
and the spur are not unlike each other, and at first I thought there
were three spurs and two toes. They look altogether too big for
the animal, and give it a far from graceful appearance. The
spur and the extended toe are of about the same length, and equal
to about one-eighth of the out-stretched animal. When feeding
in the open, it may be seen with all four toes extended and planted
on the glass ; it has then a very peculiar appearance, as if resting
on four props or stilts ; and stranger still is the appearance when
it uses the spur as a fifth prop. It occasionally may be seen
balanced on the spur alone, but very rarely are the toes all with-
drawn at the same time ; two is the commonest number extended,
and these the two next the spur. The tip of the toe is very small,
and when it is withdrawn the sheath invaginates to about half its
length, when it reminds one of a cylindrical bag, or a suspended
knickerbocker leg, slightly longer than broad. It is a rather
grotesque sight to see the four great cylindrical bags pendant
alongside each other. The toe tips may usually be seen peeping
out in the middle. Occasionally a toe may be shot out with
great force. The toe muscles are exceedingly strong, and when
extended the whole is very taut and rigid. Each toe has its own
sheath, and can act independently of the others. When exserted,
the toes are planted well apart, and can be seen projecting outside

BDELLOID ROTIFERA OF SOUTH AFRICA. 51

the body width, and the tips form the corners of a figure, almost
a square. The convex bend of each sickle is outside, and the
inner concaves face each other diagonally. The spur is of ellip-
tical form, and is motile at the base, at least it can be bent down-
wards.

The rostrum is of the usual Philodine type, and is short and
stout. It has a double frontlet, and bears long cilia, which are
more powerful than those of the corona. It is capable of taking
an extremely firm hold. When the animal is feeding, the rostrum
is not tossed over.

The corona might be looked on as decadent, with the whole —
wheels and pedicels — reduced to thin discs ; or — what is much
more probable — as rudimentary, and advanced half-way in the
evolution of a corona of the Philodina-tyi^e, from a prone face of
the Diglena-type.

On the ventral face of the post-rostral segment, is seen a double
rotulate arrangement, somewhat like two thin discs inset in the
surface, and barely rising above it. These project very slightly,
right and left, over the segment, and probably bend slightly
towards each other. There is a narrow space or alley between.
Along the rims of these discs, cilia are borne up the centre and
round towards the posterior, where the discs are not well defined
and the cilia are not visible. Just here — at the back of the
wheels — the body depth increases in the ventral direction, and,
projecting almost over the posterior of the discs, prevents a clear
view of the back of them. This high boundary determines the
oral entrance, into which the alley between the discs leads. This
alley, down which the current streams, would thus be analogous
to the sulcus in Philodina.

The gullet is extremely short, as the jaws come almost to the
orifice, but do not project. There is a short oesophagus, similar
to that seen in some species of Ploima between the mast ax and
the stomach.

M. falcatus is closely plicate, and many samples are so wrinkled
and reticulated that the optical difficulties are increased to such
an extent as to make it almost impossible to see the internal
parts. These wrinkled specimens are usually seen after the
water has been kept for a day or so. Seldom are live specimens
found after the second day in the bottles, even when the water
has been aerated periodically. This, taken with the fact that

52 W. MILNE ON THE

their habitat is in rushing water, seems to indicate that a
plentiful supply of oxygen is necessary.

The shape is variable ; even when creeping it may keep the
trunk fairly stout, or may attenuate it to a very considerable
degree.

M. falcatus has two methods of progression. It has the
ordinary leech-like manner of creeping, when it takes a very firm
hold with the rostrum, draws up and plants the foot with a rabbit-
like hop, and then shoots forward the head again. Its speed is
by no means great, and in the open it usually takes but one or
two hops at a time, then squatting on two, or it may be four toes,
it keeps on swaying the head only, up and down and all round in
a restless way, with the cilia of the corona and rostrum vibrating
energetically, and the jaws in motion. It can also proceed by
swimming, but in a rather helpless rolling sort of way. It aids
the effect of the cilia by contractions of the body, and even then
the motion is little more than visible. In its habitat, where the
water flows swiftly, its power of swimming would be practically
useless to it when dislodged from the moss.

It seems to be most at home when creeping about in the moss.
It hops from branch to branch, the head searching tirelessly all
about. Every now and then the rostrum is pushed hard against
the moss, when with a decided snap it may be successful in
breaking off some particles ; it then bends the rostrum down over
the corona, and thus with the aid of the cilia, which vibrate
furiously, guides the food towards the oral entrance. Frequently
when exploring the moss, it jerks back its head at the most un-
expected times, a most irritating habit, which also characterises
the Adinetae, whose manner of feeding is somewhat similar. It
is a great gymnast and seems to enjoy itself most thoroughly
when, attached by perhaps two toes high up on the rubbish, it
happens to throw its head and body out into the open. It
squirms and contorts itself into most fantastic shapes, without
the least impression on the foothold. The muscles of the toes
and the robust foot are so powerful that it can maintain itself for
any length of time, straight out and tense — with no support
but the toes — notwithstanding the extraordinary contortions of
neck and trunk indulged in ; and quivering all the while with
excitement and pure pleasure. At times it sways round with
the toes as a pivot, and without the slightest sagging in the general

BDELLOID ROTIFERA OF SOUTH AFRICA. 53

horizontal direction. Without losing its hold, it may even bend
its body quite round on itself, and search with the rostrum along
the moss and rubbish to which the toes are attached, scraping off
particles as already described. It can search in this way, without
once shifting its hold, a circle of which its body is the radius — a
provision of great service to it, as it lessens the chances of its
being swept away by the swift current in which it lives.

There are the usual telescopic joints on the foot and neck,
and though these slip out and in at times, I do not remember
ever having seen one contracted into a ball. Dead specimens
are always fully extended, with two toes showing the sickle shape,
and two contracted into their sheaths.

The jaws at a first glance seem to be of the nature of some of
the Ploima, but are quite different. They are in two parts (right
and left) exactly alike, without any connecting single fulcrum.
The mallei are of the simplest, consisting of two rods jointed
together, both mallei being in the same plane. In the normal
jaws nearest in general appearance, e.g. Albertia, the central
rami and fulcrum are united together and form one part. In
M. falcatus, however, the fulcrum has been, as it were, cut in two.
There are thus two exactly similar portions (right and left) quite
separate from each other, and
accordingly different from any y

arrangement obtaining among ^

the Ploima. Each fulcrum has
become an exceedingly short and
minute rod, visible only under
very favourable circumstances.
It is transposed to the anterior
and lies between the uncus and
ramus ends, articulated or mus-
cularly attached to each. There
is evidently a glassy plate con-
necting ae and ce^, for in some of the larger examples several
fine striae were seen between, thus indicating a link with the
Philodina jaws.

The jaws seem to have two actions : a blinking, pecking action,
somewhat like that of some of the Notommata ; and a slightly
rotating one, a little approaching that of Philodina, but jerky
jiistead of the even, steady motion of the latter.

54 W. MILNE ON THE

The nibbling, pecking action would be produced by the shooting
forward of the two halves towards d, without any rotation or
alteration of the direction of the planes a c e e^\ and then
reversing the action. The rod ah has considerable freedom
at the point h.

The second action seems to be produced in something like the
following way. When the rods ae are pushed inwards and
downwards, the rami ce^ will bear on each other at the top ends,
and as the pushing is continued will rise upward and forward —
acee^ being rigid planes — and h will be shot forward towards
d ; the whole action producing a grinding, rotating and forward
movement at the fi'ont of c e^. The point e in the above action
apparently approaches e^ but does not in reality, for as e goes
down e^ rises, giving the rotating movement which would not
be possible if the planes a c e e^ were not rigid.

When the reverse movement takes place, 6, 6 may be brought
down as far as to bring the unci in a straight line, throwing par-
ticles that may have been caught on to the grinding surfaces of
the front ends of the rami and possible parts of contact below.

It seems to me that there are here all the elements of the
Philodina jaws. The two halves of the jaws of M. falcatus re-
present the framework of the Philodina subquadrate parts ;
all the evolution required would be a thickened margin to the
glassy plate between, and soldered on to e and e^ ; the joints
in the mallei soldered ; the rami and unci points muscularly con-
nected ; and the minute rods thrust under, and thus taking the
position of the double fulcrum in the Philodina jaws.

In the Philodina jaws the only parts soldered together at the
front and back of each half are the borders of the surface which
carries the teeth, they at least appear so. The ends of the
rami are only muscularly attached. I can find nothing at all
that could be considered a fulcrum where Gosse (1) represents it
to be. The fulcrum of Ploima is represented here by two chisel-
faced teeth (PL 3, fig. 3e) opposing each other, one on the keel
of each ramus about one-third back from the anterior. Strong
muscles connect them with the front of the jaws. The outside
borders of the surfaces carrying the teeth and the striae are the
mallei, and the inside opposing faces, each of which appears some-
what like a triangular file in shape, represent the rami. Round
the jaws are three great muscular masses, two from the front

BDELLOID ROTIFERA OF SOUTH AFRICA. 55

round the shoulders aud backwards, and one from behind and
under. I have seen what I took to be a muscle attached to the
bottom mass and branching upwards into two which are fixed,
one each, to the posterior ends of the rami. When the jaws
begin to act, the first motion is usually a downward one in the
centre. This would be caused by the pulling of the branching
muscle referred to. As the pulling is continued, the chisel-faced
teeth are ground against each other and downwards, and throw
up the mallei. Then the muscles from the shoulder muscular
masses act, and pull the mallei down ; the chisel-faced teeth
oppose each other at their lowest points, and th^ow the inside
faces of the jaws (rami) up and away from each other with a slight
rotation, as the front ends of the jaws are muscularly connected
while the posterior ends are free. The jaws separate so far in
P. grandis that when open the chisel-faced teeth can be seen
between them from above. In each up-and-down motion the
shock can be observed, just when the full pressure comes to bear
on the opposing chisel faces. The resulting slight rock on the
point of pressure can be seen.

The position of Monoceros falcatus seems to be somewhere
between Ploima and Philodina. There are features which seem
to show that it might very well have been evolved from free-
swimming ancestors among the Ploima. The jaws, corona and
spur might have come from some tailed form of Pleurotrocha.
Probably there were parallel roads attempted from Ploima to
Philodina. M. falcatus on one of these failed to get all the way,
and Microdina paradoxa also failed on another road.

One is tempted, at this stage, to look for signs, among the
Bdelloida, of any links towards other branches of the Eotifera.
There are the horn-like processes of the corona of Ceratotrocha
cornigera, which might point the way to the Floscularia, possibly
the farthest advanced of the Eotifera, as one of them, F. moseli
(5), has rudimentary kidneys and is thus probably the highest
of all.

Habitat. — Not far from Algoa Bay, to the west along the coast,
are the grass-covered Cape flats. Walking across these flats
uear the farm of Draaifontein, one suddenly comes on a narrow,
deep ravine, whose existence was quite unsuggested by the flat
surroundings. On descending to the bottom, through the scrub
and treeg, b, little stream is found, whose bankg a,re covered

56 W. MILNE ON THE

with maidenliair and other ferns. The ravine is not long, and
meets with another larger one at right angles. Within a few
feet of the junction, a large rock crosses the bed of the smaller
ravine, and slopes steeply down stream. Over this declivity,
which is covered with moss, the water glides swiftly. On this
moss-covered slope is the home of Monoceros falcatus, and there
it literally swarms. For several years I found it there without
fail ; then for two or three years I thought it had disappeared, as
I could not find a single specimen in the moss brought to me from
the ravine. It then occurred to me that the waterfall had been
missed, so on the next opportunity I had the moss taken from the
rock, and sure enough the animal was again found in abundance.
It seems that it requires swiftly flowing water to thrive, at any
rate this rock was the only place where I found it flourishing.

Family Philodinidae.

DIDYMODACTYLOS gen. nov.

Generic Characters. — Bbelloida, having two toes only.

Didymodactylos carnosus sp. nov.

PI. 2, figs. 2-2c.

Specific Characters. — Large and massive; corona one-half
wider than collar. Antenna very short ; no eye-spot. Invest-
ment of stomach yellowish. Foot very short, of four segments.
Spurs short, straight cones rising out of great globular or spherical
bases without interspace. Toes, two. Teeth, four or five. Size,
l/50th inch.

This is a handsome animal, so Philodina-looking that I took it
for one without suspicion, until I caught sight of the toes, and
became aware that it had only two, distinct and well developed,
and with no signs of any reduction. They are extruded from
a narrow rectangular orifice, and can be seen extending through
the sheath (PL 2, fig. 26). In 1886 (2) I pointed out that the
number of toes formed a very natural means of generic distinc-
tion ; and as that method has been utilised by Bryce in his classifi-
cation, it followed that a new genus was rendered necessary for
this animal.

The corona is very wide and attractive, and equal to about one^
fourth of the length of the animal when creeping and fully eX'

BDELLOID ROTIFERA OF SOUTH AFRICA. 57

tended. It is one-lialf wider than the collar and twice as wide as
the neck. The sulcus width is about three-fourths that of each
disc, and is fully occupied by the boldly outlined and charac-
teristic upper lip, consisting of two fine lobes and an intervening
part with a boldly notched anterior border. It is rather difficult
to get a good view of the corona, as the head is kept moving cease-
lessly when feeding. Even when creeping, it has a restless,
jerky, fussy manner. Though it does not get over the ground
very fast, it is very forceful, and brushes its way under and
through the rubbish with great vigour.

The rostrum is stout and fairly long, and has a triple arrange-
ment of the lamella. There is a well-marked rosette round the
closed mouth. The antenna is a mere stump, about one-sixth
of the neck width. There are no eye-spots on the rather large
brain mass.

The jaws are relatively small, and are crossed by four or five
teeth of no great size. There is great difficulty in making quite
sure of the number of teeth, on account of the restless habits of
the animal and the density of the integument and parts overlying
the dental bulb. There is a large gland below the mastax, darker
in colour and finely granulated. The lumen is narrow and has
a yellow investment. The intestine is large, and the contractile
vesicle small and of short period.

The rump is well marked off from the trunk and is heavy.
The foot is cleanly modelled, very short and equal to about one-
twelfth of the total length. The second and third segments are
each very short. The foot glands are very heavy and extend well
up through the anal segment. The spurs are very distinctive and
handsome ; the great globular bases are quite unique, and the
short cones seem set into them.

The foot and trunk are delicately and closely stippled.

The only Bdelloid nearly related to this is Mniobia tetraodon.
In some points there is a considerable resemblance between the
two. The samples of M. tetraodon which I have seen agree with
those found by Bryce in the upper lip and size, but are more in
accord with Janson's account (3) in the spread of the corona. I
find cases of corona to collar as 15 : 14. In some the proportion
was slightly greater, but none showed so great a proportion
as Bryce mentions. The upper lip in mine agrees with Bryce' a
description (4). The upper lips in the two species are not very

58 W. MILNE ON THE

different and each has a very short antenna. D. carnosus has a
wider spread of corona, a more opaque integument, and is more
massive, more especially towards the rump. It has four segments
in the foot, while M. tetraodon has three as stated by Janson. The
bases of the spurs in M. tetraodon are not globose but irregularly
swollen, seen best ventrally towards the middle, and are relatively
smaller. The spurs of M. tetraodon are curved and longer. In
D. carnosus the two toes are distinct (fig. 2c) ; in M. tetraodon there
is but a suggestion of two toes, caused by a slight pinch on one
side, but the two parts on either side of this pinch never alter their
relative positions towards each other, Avhen exserted, which they
would do if there were two toes. D. carnosus is of a much
livelier disposition. M. tetraodon would seem to be a divergence
from D. carnosus or some common ancestor.

Habitat. — Ground moss found growing very sparsely in grass
at Springfield near the river, Uitenhage district. It was exposed
to the broiling sun, and subject to long droughts. Very rare.

Genus PHILODINA (Ehr.).
Philodina praelonga sp. nov.
PI. 4, figs. 5-56.

Specific Characters. — Of a fairly deep yellow colour, tinged with
red in the alimentary tract. Long and narrow ; the rump and
foot taper gradually from the end of the trunk, which is almost
uniform in width. Corona is very wide relative to the body ;
about one-half wider than the collar, and more than one-fourth
of the animal when creeping. Antenna is equal to nearly three-
fourths neck width. Two lemon-coloured eye-spots on a small
brain mass. Jaws not large, squarish ; teeth, three large and one
small. Foot has four segments. Spurs short, practically parallel,
with short, straight interspace. Toes, four ; two front ones stout
and long, the other two quite small. Size, l/50th inch.

This is a long, narrow animal which does not broaden out any-
where when creeping, and very little when feeding. It creeps
with a sort of dead pull and progresses rather slowly. It swims
very freely, as might be expected, seeing its home is in pools. The
corona is most elegant and attractive, and is very wide-spreading.
Corona, collar and neck are to each other as 35, 25 and 15, and
in some cases the corona is as much as oae-half wider than the

BDELLOID ROTIFERA OF SOUTH AFRICA. 59

collar. The wheels are very shallow and practically circular in
shape, and the rims bearing the cilia form complete circles except
for the gap over the sulcus, which is very small owing to the
slight depth (dorsal to ventral) of the sulcus. The sulcus (right
to left) is wide and the bottom boundary of it is a sharp, thin
ridge.

When the animal is feeding, the head is placidly swayed up
and down and round about, each great wheel with its vibrant
cilia flashing out brilliantly, in varying shades of yellow, as the
incidence of the light changes ; now a circle, now some form of an
ellipse. The effect is heightened by the lifting or screwing up,
at times, of the outside boundaries of the wheels farthest from
the sulcus, bringing them more towards the position facing each
other, and foreshortening the view of the wheel. The cilia flash
in great waves, and the whole effect is most striking and
beautiful. When viewed from above, the discs give almost
the best representation of two revolving wheels of any species.

Slight prominences on each disc bear two long setae. On
account of the shallowness of the corona, the borders of the
upper lip are very flat. The lateral borders have to rise very
little from the collar to reach above the sulcus bridge. There
they bend round at sharp angles between which the anterior
border sags a little, so as to be slightly concave. The sulcus
ridge, with its ends elbowing up into the discs, often shows
over the upper lip, almost parallel.

Brushes of scrubby setae protrude from the long antenna. Two
eye-spots, very distinct, are seated on the brain mass, which is of
an inverted pear shape, well defined, but very small for such a
large animal. Jaws of medium size, and rather square in outline,
show on each side three large and clearly defined teeth and one
smaller, not greatly larger than the striae, but whose point can
be distinctly made out. Jaws and borders are often stained
deep yellow.

The rostrum is stout and has a double lamella. From the
posterior of the rostrum back to the end of the trunk, the width
is practically uniform when creeping ; there is just a gentle
inward curve between the antenna and mastax. No swelling is
visible in the lumbar region, its outline tapers gently into the foot,
and this tapering is continued down to the spurs. At the ankle
there is a slight sudden narrowing. The outside edges of the spurg

60 W. MILNE ON THE

are practically parallel — the width at the ankle being 4*5, and
across the spur points 5. A straight interspace, nearly half the
width of the spur base, separates the short spurs, which are rather
less in length than the width of the ankle. For a very short dis-
tance from the interspace, the inner border of the spur proceeds
parallel to the outside edge, and then diverges straight to the apex.
I have frequently seen the spurs clipped together in an inward
direction, but have never observed the points farther apart than
the normal. The spur segment is continued well back from the
spurs to the toes. Very noticeable is the difference in size of the
toes (fig. 56), the front ones having at least twice the diameter
of the back ones, and being much longer. About the middle of
the toes, the diameter is greatest, and from there they narrow
slightly to the extremities, which are terminated by peculiar
cylindrical brushes. Muscular threads proceeding upwards from
the toes are seen very distinctly.

The trunk is widely plicate.

Young specimens have seldom any yellow colour.

P. fraelonga can be kept for a considerable time in the bottles,
provided the water is renewed frequently ; and the eggs hatch
out. They do not seem to remain long healthy in an ordinary
slide.

Habitat. — Draaifontein farm ravine, along with M. falcatus ;
also abundant in some of the pools in the larger ravine below.

Philodina grandis sp. no v.

PI. 3, figs. 3-3^.

Specific Characters. — Body long and stout ; bright yellow in
trunk, but paler towards extremities. Corona very large and
widespread, equal to well over one-fourth of the fully extended
animal. The sulcus is nearly as wide as the disc. A stout peg
on each wheel carries at least three setae. Rostrum stout, with
trifid lamella. Antenna long and stout, equal to one-half of neck
width. Jaws very large, heart-shaped with four very large teeth
and one smaller. There are no eye-spots. Foot is long and fairly
stout. Spurs narrow and equal to width of ankle, with narrow
convex interspace. Two of the toes are very large. Trunk and
rump are very closely stippled. Size, l/50th inch with frequent
samples up to l/40th inch.

feDELLOID ROTIFERA OF SOUTH AFRICA. 6l

This is the species of Philodina referred to by Murray (10), who
gave some figures of it. The colour is sometimes light lemon,
but usually is bright yellow in the trunk. The ovary frequently
shows a red tinge. It is a very large and powerful animal, one of
the largest of the moss-dwelling species ; and though not very
much longer than P. fraelonga, is much more massive. It quite
rivals M. russeola, but is not quite so heavy in the rump and foot.
It creeps very steadily with long strides, planting the toes well up
under the head, and without any jerky action. When feeding, it
keeps on ceaselessly swaying the head round about, and up and
down, in a very lazy sort of way, so that the focus is being con-
tinually slowly altered.

The corona is of very great size — up to 1/1 35th inch in the largest
examples — it is larger, and even more striking and handsome than
that of P. fraelonga, with equally circular discs. On account of
its wheels being so round and wide, and the ciliated rims stand-
ing out so clear of the pedicels, there is presented the most perfect
illusion, in any rotifer, of two cog wheels in motion. There seem
to be about fifteen cogs or triangular bunches of cilia on each
wheel. Some friends, on being shown the wheels, could hardly
be persuaded that there was no rotation. The corona, collar
and neck are to each other in the proportions 45, 30 and 20.

On each wheel is a stout peg bearing a bunch of, at least, three
long Setae. On the ventral side of the sulcus, just between the
pedicels, there is a ridge or membrane with a deep gap, which
evidently exercises a selective action on the particles streaming
past. The sulcus is nearly as wide as the disc, but the discs lie
so close on to the sulcus that the great cilia play in and round it
in such a way as to interfere almost completely with a view of
the borders of the upper lip, and to make the sulcus look narrower
than it really is.

The pedicels move independently of each other ; one wheel may
be seen being twisted round or bent over, while the other re-
tains its position. Both wheels may be turned over in the one
direction, till they appear to revolve in parallel planes. Some-
times they are pushed towards each other till the straight front
margin of the upper lip becomes a deep serrated V. A very
common position is with the extreme ends of the corona bent,
symmetrically, well down.

At the first glance the upper lip seems a very simple one, but to

62 W. MILNE ON THE

realise all its intricacies takes a prolonged inspection, aided by
a good deal of luck in getting tlie animal to turn its wheels in
particular directions, so that views may be bad under the great
cilia wbicb lasb down into the sulcus, especially just under the
dorsal termini of the primary and secondary wreaths. When the
head is in the usual position it is practically impossible to see the
corners under these termini.

The secondary wreath is well developed, and passes round,
laterally, on a considerable projection which is continued lower
down towards the neck. The lower boundary of the latter pro-
jection continues round dorsally (still standing out) to the sulcus
in a wavy curve, and just under the end of the secondary wreath,
bends down and round in a tongue-like part (PL 3, fig. 3^), and is
continued in a large scalloped curve s round and up to near the
corner of the upper lip. All round the lower rim of this projec-
tion, the tongue part, and the scalloped curve, is a narrow,
glaucous, fleshy-looking band. This cannot be considered part
of the upper lip, I think, as it does not start from what is usually
considered the collar. Just below the lateral projection is the
collar, and from it there proceeds a band r (placed lower in the
figure than its real position to show more clearly), usually shadowed
or covered by the projection above. When the wheel is screwed
up and forward, the band can be traced up to the middle of the
tongue part t already mentioned. There it seems to stop, but
as it looks to be at a lower level, it evidently passes under. From
the front corner of the upper lip there passes back a thin fleshy
border — highest in the middle — down close to the other side of the
tongue part. This is apparently continuous with the band already
traced to the under side, but a good view is very rarely had
owing to the play of the coronal cilia, and even at the best is not
quite free of interference. This band, then, which apparently
passes under the tongue part, is evidently the border of the
upper lip, whose front margin is nearly as wide as the sulcus, and
practically straight.

There is another line which starts from the collar alongside the
first, and half-way towards the sulcus begins to widen out into a
broad band u, which passes close to, and is often in contact with,
the tongue part, and then bends across immediately in front of
the rostrum. This band does not seem to lie flat, but is raised a
little anteriorly.

BDELLOID ROTIFERA OF SOUTH AFRICA. 63

The rostrum is stout and has four or five setae on each side,
two of the longest have bulbous roots and are quiveringly vibra-
tile. The lamella is trifid (fig. 3/), but only so seen when the
rostrum tip is fully exserted, and pressed firmly against the cover-
glass preparatory to pulling it away. Murray (10) states there
are two separate lamellae, but the appearance of two is due to
the middle part being hidden when the tip is only just showing.
Before the grip of the glass is taken, the lamella is clearly seen
with a fold in the middle, and not two separate parts. When the
rostrum is tossed back, it has a peculiar appearance — two roundish
parts in an almost rectangular casing.

There is a curious ribbon of thin skin, of considerable width,
extending forward from the posterior of the rostral segment, and
right round, at least dorsally and laterally. It stands clear of
the segment at its front. Murray's figure seems to show it.

The antenna is stout and long, and equal to one-half of the
neck width. There are three knobs across the top, and three
brushes of short setae protrude ; muscle or nerve threads pass up
the middle. It is independently motile and it frequently gives
a decided bend, the top segment also does so by itself. It is
evidently very sensitive ; for preparatory to exserting the head
when the body is contracted, the antenna is gently protruded,
and if it should meet an obstacle is drawn back, but again a
second or even a third time it may be quietly pushed up to the
obstacle, as if to ascertain its nature. The animal has evidently
two very sensitive feelers : the antenna, and the cilia with the
bulbous roots in the rostrum.

There are no eye-spots on the medium-sized brain mass.

The jaws are extremely large — l/520th inch — and somewhat
heart-shaped ; and the borders are thickened with rough brush-
like extensions (PL 3, fig. 36) often stained bright yellow. The
four large teeth are pointed, and of a peculiar shape — swollen
towards the inner ends and tapering off outwards. The fifth
tooth is quite half the size of the largest, and the striae are very
large. The double fulcrum (PL 3, fig. 3e) can be seen, during
feeding, when the jaws are horizontal and open.

The vascular canals are prominent in the neck and are sur-
rounded by a large amount of floccose matter, and there are at
least five vibratile tags on each side. There may possibly be more,
as the internal structure is not easily discernible on account of

64 w. MILNE On the

the refractive, muscular, thick, fleshy integument, the deep
plicae, and the small oil globules in the stomach investment.
There are also minute round particles, like those so common in
Floscularia, floating in the perivisceral fluid and streaming with
every movement of the body. These often collect at parts and
cause a reddish-brown appearance.

The rump is fairly long, but the anal and pre-anal segments are
not well marked off from each other ; the lumbar plicae, however,
give some idea of how far the pre-anal segment extends (PI. 3,
fig. Sd). The intestine and contractile vesicle are thick- walled,
but not particularly large for the size of the animal. Heavy
foot glands and muscles penetrate through the anal segment ;
and two curious muscles seen over the contractile vesicle (fig. 3d)
are apparently part of it, as they are pushed on to each other as
the vesicle contracts.

The foot is longer than usual in the moss-dwelling Philodinae.
There are four segments, through which pass two great glands and
strong muscles. The spurs are characteristic, the interspace is
slightly convex and equal to the width of the base of the narrow
spur. The length of the spur is equal to the width of the segment
at the point of attachment, but the spurs are attached not to the
widest part of the segment, as is usual, but below it. I have
never seen the form which has spurs exactly like M. russeola
as figured by Murray. The toes are not far separated, the front
two are enormous, and the other two much smaller. Cord muscles
from each toe are very distinct, whether taut, or slack in loops.

The body is stippled in the most delicate and beautiful way.
The stipples are exceedingly small and are arranged in rows so
close together that, viewed at certain angles, as against the inside
of a ridge, these rows look like delicate striae on a dental bulb.
When the surface is viewed at right angles, the stipples are seen
to be minute dots arranged in rows excessively close together.
When the focus is slightly lowered, the appearance is that of
hollows or tiny cells, and lower still the dots reappear. The
middle focus — in good specimens — gives a brilliant effect, the
perfect similitude of a miniature honeycomb whose cells have
been reduced to almost infinitesimal dimensions. The stippling is
difficult to make out on some specimens, but in general it is
quite easy. Occasionally it can be seen most brilliantly on a
dead shell or skin.

BDELLOID ROTIFERA OF SOUTH AFRICA. 65

Philodina grandis is found in enormous numbers, occasionally,
in isolated small pieces of moss. When there happened to be
many on a slide, it was generally found that after a time they
managed to congregate together in groups, as if fond of company.
I have had as many as two dozen in view at once under the one-
inch objective. They were lying stretched over and all about
each other, some on moss with their heads down, others below
with their heads stretching out, and nearly all feeding at
the same time. Their coronae, all unfurled, swaying here and
there, formed in the artificial light a most entrancing sight, flash-
ing golden yellow amidst the green moss, and setting particles
floating about in a perfect whirlpool. They seemed to take no
notice when struck by a fellow Philodine, but decidedly objected
to the impact of a swirling piece of moss.

Habitat. — Ground and rock moss. Uitenhage (Euphorbia
Kloof), Grahamstown and Somerset East. Widespread and very
numerous in isolated fragments of moss.

Philodina childi sp. nov.
PL 3, figs. 4-46.

Specific Characters. — A very large and remarkably bulky
Philodina ; trunk of a dark brownish appearance. Rostrum
stout. Antenna rather less than half the width of the neck.
Trunk quadrate. Foot short and narrow — of five segments.
First segment has two spurs set near each other. Toes four,
short. Corona very large. Jaws large, teeth J 2 J. Very
delicately and clearly stippled. Size l/40th inch.

This is, I think, the largest Bdelloid I have seen. I took it,
for some time, for an overgrown variety of M. quadricornifera, as
there is a considerable resemblance in general appearance. To
my great surprise, however, when I observed it, after a time,
creeping with its foot against the cover-glass, I discovered that it
had four toes, and so was not a Macrotrachela after all.

Its length and bulk are both remarkable. It has a strong,
thick muscular integument so that its shape retains wonderful
uniformity, and varies little in outline. The lumbar region and
posterior trunk are rather dark in colour, and almost opaque.
It is a slow, laborious creeper and feeds freely. The rostrum is
stout and has a large double lamella, each side of which has three

JouRN. Q. M. C. Series II. — No. 78. 5

66 W. MILNE ON THE

straight setae which quiver, but do not lash, and some shorter
ones which were not seen to quiver.

The antenna is stout and fairly long, and the brain mass is
small, far back and without eye-spots. Flocculent matter sur-
rounding the vascular canals makes them very prominent in the
neck. The jaws are elongated and bear four teeth on each side ;
two of these are very broad and large, and two — one on each side
of the large ones — smaller but considerably larger than the extra-
ordinarily large striae, and with well-defined points.

There are three ventral nucleated glands under the mastax,
probably gastric; Two or three decided lateral ridges can be
seen on the trunk, but there is no wrinkling when creeping.
Quite characteristic is the shape of the lumbar region with stifi
borders, and the anal and pre-anal segments not well marked off
from each other. A long and convoluted stomach ends in a round
and not very large intestine. The contractile vesicle is large and
of fairly short period when feeding, and when it contracts crumples
in towards the middle slowly. For so big an animal the foot is
narrow ; the spurs on the first segment are flat and triangular,
and set very near each other. Somewhat similar to those of M,
quadricornifera are the ordinary spurs, but less deeply cut between
the tips, and more approaching a straight line. The four toes
are short and stubby and not far separated from each other, the
front two are the thicker (fig. 46).

The corona is very wide-spreading and well over one-fourth of
the length of the fully extended animal, and nearly as wide as
that of P. grandis. The sulcus is slightly narrower than the
wheel. A thin ridge or membrane with a V-shaped gap was seen
ventrally between the pedicels, similar to that in P. grandis.
Corona, collar and neck are to each other as 43, 31, 24.

The striking upper lip is rather complicated and will be best
followed from the figure (PL 3, fig. 4a). No central setae
were noticed on the wheels. P. childi is stippled in a manner
precisely like P. grandis; the stippling is equally beautiful, with
the same honey-comb appearance, and it is never difficult to make
out ; the trunk, lumbar region and spurs are the parts stippled.

An egg, very large, broadly oval, and dark in colour, was
deposited on the slide five days after the animal was enclosed,
and the division of the cells watched for some time.

There is another animal almost as large, which I have thought

BDELLOID ROTIFERA OP SOUTH AFRICA. 67

miglit prove to be a variety of P. childi. It has a differe nt upper
lip, though it resembles it in several details, but I was unable to
study it sufficiently.

Habitat. — Grahamstown. Very rare. Mr. Child, formerly
of Uitenhage, used frequently to bring me moss from different
places, and on one occasion brought the small piece of moss from
Grahamstown which contained this animal, and I have named it
after him.

I have never met with P. childi since, though I have had moss
very frequently from Grahamstown.

Philodina nitida, sp. nov.
PL 5, figs. 9-9a.

Specific Characters. — Trunk rectangular ; occasional specimens
attain a large size. Lumbar region and foot rather light. Colour
yellow, fairly deep in the older specimens. Furrowed longi-
tudinally, but has a very smooth skin. Two large lemon-yellow
eye-spots. Antenna long, between one-half and two-thirds neck-
width. Jaws very large, with three great teeth and a fourth
just smaller. Spurs of similar shape to those of P. rugosa, but
held at different angles. Corona large ; sulcus rather less than
the disc ; upper lip clear cut, distinctive. A seta on small
pimple on each wheel.

Size, first samples, l/70th inch, later examples up to l/50th inch.
This is an attractive, neat and dapper animal, modelled and
built on clean lines, and has a clear, smooth skin giving a brilliant
shining appearance. In the large specimens the colour is a deepish
yellow all over, except the foot and lateral plicae, which latter are
glassy-looking and fleshless. Frequently the deep shade occurs
only in the alimentary track. Ovaries were seen of a pink tinge,
and occasionally the wheels showed saffron.

It has a double lamella, rather small, and not so transparent
mica-looking as usual ; attached to the base of the lamella is a
fleshy rim, also double, on which are situated a considerable
number of setae, hardly, except two, projecting beyond the rostral
sheath. These two and other two have bulbous roots, and have
a quivering motion. The neck is very heavy and widens con-
siderably at the dental bulb.

Scrubby setae are borne on the long antenna, whose two seg-

. 68 W. MILNE ON THE

ments are nearly of equal length. Very large jaws — l/780tli inch
— carry four teeth each ; three are very large and the fourth only
just smaller ; the striae are also large.

A good presentment of a fox's face is given by the brain mass,
with its two large eye-spots. The trunk is rectangular — not
much longer than broad in the earlier examples found — and
has deep and numerous longitudinal furrows. The lumbar region
is comparatively light for such a large animal, and has a thick-
walled intestine, oval and very long ; and a contractile vesicle
which is fairly large.

The foot consists of four segments, and has spurs which are not
unlike those of P. rugosa in shape, but more bent and decurved.
Each spur is as long as the width of the ankle ; a straight or
scarcely perceptibly convex interspace separates the spurs, and is
almost equal to twice the width of the spur base. The spurs
seem to be feeble, and in all the earliest specimens one was twisted
and not symmetrically placed with the other. Afterwards, the
commonest form had the two spurs parallel, the outside border of
one convex and the other concave. In one or two of the large
examples last seen, the spurs were both convex on the outside
borders.

No great distance separates the toes ; the front ones are thick
and fairly long, the back ones thin and short.

A large and well- developed corona is one-fourth of the length
of the fully extended animal, and bears long cilia which play in
great waves. In one giant example the corona was l/180th inch
wide, but the average width was about l/250th inch. The pro-
portions of the corona, collar and neck, are to each other in
average specimens as 25, 20 and 15. The upper lip is distinctive.
A lobe from the wheel meets the highest point of the upper lip ;
and occasionally a tooth jag or two show in the middle notch, but
probably belong to the sulcus. A seta rises from a pimple on
each wheel.

It creeps at a fair speed, and sometimes hitches the foot round
and forward, with a swing. It feeds freely and usually lies back
over the foot when feeding.

A long tongue-shaped gland lies below the mastax, ventrally.
Heavy foot glands run high up into the anal segment.

Habitat. — Ground moss, the Hatchery, Stellenbosch. Found
in fair abundance.

BDELLOID EOTIFERA OF SOUTH AFRICA. 69

Philodina nitida var. decens.
PL 5, fig. 10.

This animal differs from the species in several points, but comes
sufficiently near in jaws, upper lip and spurs to be considered a
variety.

It is of a very elegant shape when creeping. It is large and
stout, and has a heavy neck and fairly heavy rump. There is a
large brain mass with two large yellow eye-spots.

The foot is short, and contains heavy glands. The spurs are in
shape like those of P. nitida, but symmetrically placed ; and of
the toes two are large, and the other two much smaller. The
rostrum is stout, and the double lamella, which is not very easily
seen, bears several stiff setae. The antenna is rather thin and
about one-half the neck width.

The teeth are exactly like those of P. nitida, and the striae
are very large and easy to count — 10 behind the teeth. There
is a long tongue-shaped gland below the mastax.

There is little distinction between the anal and pre- anal seg-
ments. The intestine is oval and very long.

The corona is large and beautifully balanced ; and the propor-
tions of corona, collar and neck are to each other as 30, 20 and
15. The upper lip consists of two rounded lobes with a fair
interspace. The wheels are frequently screwed, or brought nearer
each other, causing serrations in the upper lip interspace. There
is a slight prominence bearing a seta on each wheel.

The colour is faint pink and in some pale yellow. The pink
colour is little more than a tinge, but the changing shades are
wonderfully fine, as the animal doubles up and shows greater or
less depth of flesh at parts, especially in the dental segment.
Size, l/50th inch.

Habitat, — Stellenbosch in ground moss.

Philodina inopinata sp. nov.

PI. 4, figs. 6-66.

Specific Characters. — Of small size, with long narrow foot,
narrow cylindric trunk and stout neck. Antenna slightly
longer than neck width. Of a glaucous colour. Two eye-spots.
Teeth, three. Foot has five segments. Spurs of medium length,

70 W. MILNE ON THE

narrow, almost parallel. Toes sliort. Corona scarcely wider
than collar, sulcus narrow, upper lip triangular. There is a rect-
angular flap -like projection at the anus, which works as if on a
hinge. Size, l/90th inch.

The upper lip of this species is most difficult to examine, as the
animal when feeding nearly always stands upright on its toes, and
whirls round and round on its vertical axis ; or swims about at
great speed. It is a very timid feeder when moored, the corona
is unfurled and almost instantly closed again, and this is repeated
again and again, so that the merest glimpse, of the upper lip is
had. The corona is scarcely wider than the collar ; the collar
rises high up, and the pedicels are very short, causing some
interference between the cilia of the primary and secondary
wreaths. The upper lip is of an uncommon shape for Philodina.
It is in shape a triangle extending as high as the discs, and lying
well back into the sulcus. The stoutest part of the animal is that
between the short, broad rostrum and the trunk — the dental seg-
ment is slightly the widest — and the trunk never gains the same
dimensions as the neck, until after heavy feeding. It is a rather
slow, deliberate creeper. The antenna is very long and generally
hangs backward, with the terminal segment bending over, and
when creeping gives a side view reminding one of that of a hare's
head with the ears laid back. Some species of the genus Rotifer
also have this appearance. Long setae are borne on the antenna,
which is thickest half-way between the base and the second seg-
ment, as if swollen there.

There are brilliant eye-spots on the brain mass, well apart,
slightly elongated and set obliquely. The trunk is closely plicate.
Right from the trunk, the lumbar region and foot taper very
gently all the way to the spurs.

Quite characteristic is a very peculiar process at the end of the
anal segment. It is a thin, almost membranous, rectangular
flap, somewhat bent in and over, on the top, so that the side view
is that of a hook. When the animal is stretched to the full, the
flap lies flat down, pointing forward over the contractile vesicle.
As the animal relaxes, it stands upright, and turns down in
the opposite direction when the foot is being planted. It almost
seems as if the flap worked on a hinge. It is of the same colour
as the foot, and thus easily overlooked. It was some time after
finding the animal that I noticed it first.

BDELLOID ROTIFERA OF SOUTH AFRICA. 71

The foot is a longish one of five segments, and bears on tlie
penultimate segment spurs which are only just noticeably diver-
gent, very narrow and acuminate, with narrow straight inter-
space, and equal in length to the ankle. The four toes are short
and stumpy.

Habitat. — Draaifontein farm ravine pools, in company with
P. praelonga. Found in abundance.

When I was examining the habits and characteristics of P.
inopinata, I had rather a surprise on comparing my notes after
having examined a good many specimens. The statements as to
the spurs agreed fairly well, but those on the number of segments
in the foot were sometimes five and sometimes four, on the
number of the teeth sometimes three and sometimes two ; and the
length of the antenna was in some cases stated to be longer than
the neck width, and in others shorter. In some, indications were
noted of a triangular upper lip, in others not. It looked as if I
had had, inadvertently, two species under observation. That
there were two species turned out to be the case, but so alike
in general appearance, habits, size and colour, that I had not even
a suspicion of the fact until I noticed these conflicting details.
Yet they are two very distinct species. P. inopinata has the
spurs slightly more divergent, a longer antenna, one foot segment
more, a tooth more, a narrower corona and sulcus, a different
type of upper lip, and shorter toes. It has the flap near the anus,
the other has not. It is quite extraordinary to find two species
living together, so alike in general appearance and habits, and yet
so distinct in almost every detail.

I have never met with P. acuticornis, but I think the second
species referred to above might be considered a variety and I give
a description under the name odiosa.

Philodina acuticornis Murray, odiosa var. nov.

PI. 4, figs. 7-76.

Specific Characters. — Neck short, trunk narrow, cylindrical ;
lumbar region and foot taper gradually from trunk to spurs.
Foot consists of four segments. Spurs of medium length, practic-
ally parallel. Toes long, sharp, about equal in length, though
possibly back pair rather longer. Eye-spots distinct. Antenna
practically equal to neck width ; with longish setae. Teeth, two

72 , W. MILNE ON THE

in squarisli jaws. Corona rather wider than collar. Collar has
flap extensions. Upper lip has a wide front gently sagging in
the middle. Size, l/90th inch.

Its habits when feeding are similar to those of P. inopinata,
but if anything more provoking. The corona is rather wider, but
the upper lip is more difficult to see, on account of its less sharp
outline and its greater transparency. It rises about one-third
up the sulcus. The rostrum is not very large, and the double
lamella is far from prominent. The eye-spots are brilliant,
somewhat elongated, and set rather closer together than those
of P. inopinata.

The spurs are equal in length to the ankle width, and narrow
to a sharp point, while the interspace is equal to the width of the
spur base. Towards the points, the spurs curve upwards slightly
but distinctly, a very uncommon occurrence.

It has a habit, when creeping, of throwing itself backward head
over heels, with the four toes fully extended and gripping. Some-
times the two back toes are seen extended alongside and almost
parallel to the spurs, and seem to be nearly as long (PL 4, fig. 7).
All four toes are pointed.

This variety seems hardier than P. inopinata as it persists in
the water and on the slides after the latter has died out, but loses
much of its energy after a few hours on the slide.

Habitat. — Draaifontein farm ravine pools. Fairly abundant.

Philodina patula sp. nov.

PL 5, figs. 11-lla.

Specific Characters. — Stout, but not of great length. Colour
lemon yellow, but only the merest tinge. Antenna equal to
two-thirds neck width. Jaws not very large ; teeth, two. Brain
mass large, but no eye-spots. Lumbar region not heavy. Foot
fairly stout, of four segments. Spurs parallel, very short, and
without interspace. Corona very wide — almost twice collar
width ; sulcus rather wider than disc. Upper lip with a slight
indentation. Size, l/80th to l/75th inch.

This is a vigorous animal and a very free feeder. The rostrum
is long and stout, with a double lamella, and carries several long
setae. The antenna is long and has a considerable tubular hollow

BDELLOID ROTIFERA OF SOUTH AFRICA. 73

inside. The trunk laterally is slightly convex, and the posterior
boundary always shows straight across with sharp corners. There
are deep furrows laterally, the ridges not showing fleshy, but
having a mica-like appearance ; the dorsal furrows are broad
and shallow. There is practically nothing to distinguish between
the anal and pre-anal segments, which make up a comparatively
light lumbar region. Both the intestine and the contractile
vesicle are rather small. The foot is fairly stout, and the first
segment is long and of a distinctive shape. It curves in and then
out, ending in a distinct flange, which overlaps, laterally, the
second segment. There are three of these flanges, and a good
view can be had of them, when looking down the dorsal boundary,
while the animal is feeding in a nearly perpendicular position.
The first is at the posterior end of the trunk, and stands out very
clearly ; the effect is heightened by a broad hollow just in front
of it. The second flange is at the back of the anal segment, and
also stands well clear of the surrounding parts. The third is the
one already described at the back of the first foot segment. They
are very distinctive, and add to the general effect of the many
graceful curves shown in the outline of this animal.

The spurs are very short, slightly blunt, parallel, and having
an almost concave boundary between the tips.

The corona is an elegant one of large dimensions proportion-
ately, the width being rather more than one-fourth of the fully
extended animal. There is a single seta on each wheel, rising
from a very small peg. Short pedicels support the wheels. The
corona is to the collar as 22 : 13.

When the animal is feeding in a perpendicular position, and the
upper lip looked down upon, the front margin of the latter shows
two thick lobes, but when the animal is horizontal the anterior
border approaches more nearly a straight line. This would seem
to indicate that the lobes are much thicker, or deeper, laterally,
and thin out towards the middle. There are two green granules
in front of the rostrum, visible when the corona is unfolded.

The two teeth are not of great size. In some cases there is a
third one, not much larger than the striae, but having a point
which can be defined.

When the animal was anchored and feeding, the first two
trunk segments were always seen with the peculiar frill arrange-
ment shown in the drawing (PI. 5, fig. 11).

74 W. MILNE ON THE

The egg is a flat oval, with thirteen lateral prominences, or
rather gentle swellings, three at the end are larger than the others.
It is not unlike the egg of P. plena.

The only species at all like this one is P. plena. They are both
tubby-looking animals when feeding, and have spurs and upper
lips somewhat similar ; but the peculiar shape of the foot and also
of the first two trunk segments, the proportions of the corona,
and the presence of the flanges, easily serve to distinguish P.
patula from P. plena.

Habitat. — Ground moss, Grahamstown and Springfield Uiten-
hage district. Found abundantly, on one occasion only from
each place.

Philodina rapida sp. nov.
PL 4, figs. S-Sa.

Specific Characters. — Of fairly large size ; yellowish in colour.
Heavy neck and lumbar region, with short stout foot. Antenna
stout, and equal to one-half neck width. Teeth, three, medium
size. Intestine very large. Foot consists of three segments.
Spurs parallel and very short. Corona large with wide sulcus.
Upper lip trifid. Size, l/70th inch.

This species in general appearance is not unlike a Macrotrachela.
Its heavy lumbar region and stout short foot chiefly contribute to
the resemblance. It also creeps fairly fast after the style of a
Macrotrachela. The rostrum is fairly stout and has several long
setae, a double but rather small lamella, and cilia which have a
habit of moving slowly when the animal is feeding. A thick
antenna bears short stubby setae. There are three medium- sized
teeth in the dental bulb, which is not very large.

The trunk is plicate and strongly muscular. Large glands
extend through the foot and far up into the lumbar region. The
intestine is extremely large, and the contractile vesicle of medium
size, with a not very short period. The spurs are very short and
parallel, with a concave line joining their tips. They very much
resemble those of P. patula. The foot is very short, and of,
apparently, three segments, and the toes are also short.

The corona is a handsome one, and large — about one-fourth
of the extreme length of the body — while the sulcus is rather
wider than the disc (7 : 6'5). Corona to collar is as 20 : 13.

BDELLOID ROTIFERA OF SOUTH AFRICA. 75

The upper lip is broad anteriorly and has three lobes, or rather,
small conical protuberances. "

Habitat. — Rock moss, Euphorbia kloof, Uitenhage district.
Rare.

Philodina proterva sp. nov.
PL 5, figs. 12-12a.

Specific Characters. — Of rather small size ; glaucous in colour.
Trunk heavy, but extremities rather light. Lamella fairly large
and very transparent. Antenna short, about one-third of neck
width. Brain mass large, without eye-spots. Dental bulb small
with two medium-sized teeth. Lumbar region not very heavy ;
foot narrow and short, of four segments. Spurs very distinctive.
Corona not wide-spreading, with sulcus about two-thirds of disc
width. Upper lip wide in front and almost straight across.
Size, l/80th inch.

This is a very active and vigorous animal. It moves at very
great speed, and is most restless, making it extremely difficult to
examine. The trunk is not very transparent on account of the
number of oil globules. It feeds voraciously — a perfect pig — and
swells up into a barrel in a short time. It soon becomes so swollen
and heavy that it has great difficulty in creeping, sometimes
swinging right over sideways, as it tries to plant its foot forward.
When feeding, it occasionally bunches part of the trunk forward,
forming a constriction in the middle. The jaws work at such a
tremendous pace, that one cannot even catch the flash of the
teeth passing up and down.

Great circular muscles can be seen on the trunk and lumbar
region, and some half-dozen longitudinal ones passing up into the
cervical. The circular ones are very plainly visible, dorsally,
over the ovary and eggs, but the stomach investment is too
dense to show them well. There are some eight or ten in the
trunk and lumbar region. The glistening of the muscles gives
the trunk a very peculiar appearance in some specimens.

It has rather a short rostrum with great cilia. There is a large
hemispherical granulated gland, attached to the posterior of
the dental bulb. The contractile vesicle is large and of short
period. The foot is short, and has four segments, the second
and third being very short. Heavy foot glands extend far up into

76 W. MILNE ON THE

the pre- anal segment. The spurs are convex on the outer borders
and slightly divergent. There is a nick cut out in each inner
border, and a bold convex interspace separates the spurs.

The corona is not wide, and not quite to collar as 5 : 4. Two
membranes from the wheels come down into the sulcus, which is
about two-thirds of the disc width. The upper lip is very difficult
to trace, on account of its faintness, the refringent matter below
and the rostrum generally overlying it. The restless waving
motion also adds to the difficulty.

Habitat. — Ground moss, Salisbury, Rhodesia. Abundant in
the one very small piece of moss I got from Salisbury. I have
not seen it from anywhere else. It is very prolific. Along with
this were two other species which had practically the same spurs ;
one a variety of M. quadricornifera, and the other a variety of
M. musculosa.

Philodina scabra sp. nov.
PL 6, figs. 13-136.

Specific Characters. — Of extremely small size, short and stout ;
of no distinctive colour. Trunk roughly furrowed, of gnarled
bark-like aspect. Skin of trunk is evidently viscid, as particles
adhere to the trunk. Corona narrower than collar, sulcus ex-
tremely narrow. Upper lip a flat curve with a small fleshy sharp
peg-like protuberance in the middle. Antenna is equal to about
one-half neck width. Foot short with four segments. Spurs
are very distinctive and there are four on the penultimate
segment. The dental bulb lies well back, and bears two teeth.
Size, l/180th inch.

This extremely minute animal, in general appearance and in
details, corona and foot, looks much more like a species of Macro-
trachela than a species of Philodina. I have it, in my notes,
included among the Philodina, but have not made a distinct state-
ment about the number of toes, as I usually do. I evidently,
from my figures, did make out the number, but unfortunately
omitted to state it, and as I have not seen the animal since 1908
I cannot now remember about the number of toes ; or whether
it could have been placed among the Philodina by a slip, though I
hardly think so. When the number of its toes is next made out,
it may mean transfer to Macrotrachela,

BDELLOID ROTIFERA OF SOUTH AFRICA. 77

It is rather slow in its movements, and prefers to keep under
the rubbish, so that it is most difficult to find one when searching
for it. It is practically a matter of chance to find one, even when
one has got the moss containing it, as it is so small and generally
has rubbish adhering. Evidently there were very few in the
moss.

It is of shuttle shape, but not slender. The rostrum is fairly
stout, with prominent setae under the double lamella. The rump
and foot are stout, but do not give a heavy appearance. On the
usual spur-segment there are four spurs of moderate length. The
upper two are broad at the base and narrow to sharp points, and
have an outside convex bend. Just below this pair, and a little
inside, are two other spurs, about the same length but narrower
at the base, gradually narrowing to sharp points, and straight.
This is the only example of a Bdelloid having four spurs on one
segment.

The corona is slightly less wide than the fairly prominent
collar, and has an extremely narrow sulcus, and short pedicels.
The upper lip is rather a flat curve rising up in the middle into a
minute fleshy spike.

Habitat. — Tree moss. Van Staaden's pass, Uitenhage district.
Rather rare.

Genus MACROTRACHELA.

Macrotrachela petulans sp. nov.
PI. 6, fig. 14.

Specific Characters. — Of moderate size, but stoutly built.
Colour hyaline, with pellucid granules on trunk, not very close
together. Corona equal to collar, and sulcus to four-fifths of disc.
Upper lip rounded, bifid with gentle dent. There is a seta on
each wheel. Antenna stout, equal to one-third neck width.
Jaws squarish; teeth three, large and well apart. Stomach a
wide oval ; intestine very large, oval. Foot stout, short, of three
segments; last segment expanded into thick circular disc,
wider than ankle. Spurs very small, divergent, with wide inter-
space slightly convex. Size, l/90th inch.

The most outstanding feature of this sturdy little animal is the
large, prominent, thick-walled, perfectly oval stomach. I have

78 W. MILNE ON THE

seen notMng like it in any other Bdelloid. The wall is not rigid,
nor strong enough to prevent it wrinkling when empty. It
evidently discharges the contents under the shock of being placed
on the slide, but before the slide can be examined all the speci-
mens, perhaps dozens, are feeding vigorously, and soon are
practically buried under a cloud of floccose matter. In less than
a quarter of an hour the stomachs are all showing up as regular
ovals, fully as broad as one-half the trunk width, each oval perfect
and extending from mast ax to intestine. Sometimes when In-
fusoria are devouring the contents of a dead specimen, the stomach
and intestine, then evidently rigid, can be seen being knocked
about, like a full-blown bladder with a smaller one attached, the
walls quite distinct with a narrow connection between the two.
This connection seems to be a thick muscular stricture of the
walls of the stomach and intestine. When the stomach empties,
the walls sag in ; and when feeding again takes place, the walls
behave pretty much as those of an elongated bladder when being
slowly filled with air. After being a few hours on the slide the
animals grow sluggish, seldom move away from their position
and feed little. Some I could persuade to begin feeding at once
by the addition of a little water.

It is a steady, fairly fast creeper, and with long strides plants
its foot well under the head, and without any jerking.

The rostrum is short, but not particularly so. The lamella is
double, but not very prominent, and being very diaphanous is
not easily seen. There is a raised part surrounding the antenna,
and sloping down to the lateral borders of the segment, and the
antenna protrudes only a short distance outside this.

There is a large wide brain mass. The teeth are quite large,
widely separated, and easily defined. In no specimen did I
ever see any departure from three as the number of teeth.

The trunk and rump are granulate with not very large granules,
which are pellucid or pearly-looking and accordingly not very
conspicuous, nor difficult to overlook. These granules are not
very close together and are rather irregularly arranged.

The lumbar region is fairly heavy, but not swollen-looking, and
the contained contractile vesicle is round and very large ; and
when expanded fills up practically the whole of the anal segment.
The spurs are very small and very divergent. In some positions,
the interspace forms practically a straight line with the inferior

BDELLOID ROTIFERA OP SOUTH AFRICA. 79

borders of the spurs, but usually tbe wide interspace curves just
enough to appear convex.

The corona is bold, with a sulcus equal to four-fifths of the
disc, and the relative proportions of the corona, collar and neck
are 11, 10, 8 J. The rounded upper lip has a gentle depression in
the front margin, and just covers the bridge of the sulcus when
the animal is horizontal. There is a small fleshy tooth in the
sulcus, generally hidden, and two membranes come down from the
wheels to near the middle of the sulcus bridge. There is a distinct
lip flap at the collar.

The only Bdelloid at all near to this is C. as ferula Murray (8).
In general appearance and in some details they are very similar.
M. petulans, however, has a distinctly different type of spurs ;
has not got an exceptionally short rostrum ; has not the sharp
points on the upper lip, nor any peculiar shape of the first trunk
segment. It has a visible lamella, and the teeth never were
found to vary in number from three ; nor do the jaws show any
constriction. The most essential difference, however, is in the
character of the stomach. Murray had evidently paid particular
attention to the width of the lumen, as shown in his descriptions
of C. armillata, C. lepida and C. microcornis (7, 9). Having
thought it worth while to note these not very greatly enlarged
instances, he was not likely to have overlooked such a departure
from the common, had it existed in C. asperula. With regard to
C. asferula he neither mentions nor shows in his figure a wide
lumen ; besides, he had previously seen my sketch of M. petulans,
and would have kept an outlook for this distinctive feature.

Habitat. — Tree and rock moss. Widely spread and abundant
at times. Grahamstown ; Uitenhage district at Bulk River,
Springfield, Van Staaden's pass and Draaifontein farm.

Macrotrachela cuthberti sp. nov.

PL 6, figs. 15-156.

Specific Characters. — Of moderate size, and rather under
medium stoutness. Antenna very short, equal to one-fourth
neck width. Jaws small, square with three strong teeth. Con-
tractile vesicle large. Foot short, of apparently three segments.
Spurs small, sharp and scarcely divergent. Corona just visibly

80 W. MILNE ON THE

wider tlian the collar. Sulcus narrow. Upper lip quite distinc-
tive. Size, l/90tli inch..

This is a vigorous, active animal and feeds freely, and is of a
pale hyaline colour. It is of a semi-muscular type, for while the
muscular integument is sufficiently strong to keep a fairly regular
shape when creeping, yet occasionally the trunk loses its ovoid
form when feeding.

The corona is bold and handsome. It is hardly wider than
the collar, has a narrow sulcus and rather high pedicels. It is
difficult to get a good view of the upper lip on account of its
smoothness and glassy colour, and of the restless habits of the
animal. The part of the upper lip which rises up from the flat
curve looks somewhat like two stout rose thorns set against each
other. The small tooth process in the middle of the curve be-
tween is not always seen, and this probably indicates that it is
on the sulcus bridge. Lateral flaps are seen at the collar, and
there is a large oral entrance with a spout-shaped under lip.

The rostrum is fairly stout, and the double lamella prominent.
The antenna is very short, about one-fourth the neck width, and
almost as broad as long. Quite characteristic is the small, square
dental bulb, with very broad, thick even outline or borders, and
it carries three strong, thick teeth set well apart.

The rump is not heavy, and the pre-anal segment has a wrinkled
mark on each side. The contractile vesicle is very large. The
foot is short, and its spurs are sharp and practically not divergent.
From tip to tip, the outline is a rather flat concave, but at times
the appearance is of two short cones with a short, straight
interspace.

Habitat. — Fairly common in ground moss from Stellenbosch
and Mulder's Vlei.

I have named this species after Mr. J. R. Cuthbert of Stellen-
bosch, who kept me supplied with moss from his neighbourhood.

Macrotrachela macmillani sp. nov.

PI. 6, figs. 16-16fl.

Specific Characters. — A plump little animal, of glaucous colour,
with a slightly yellowish stomach investment. Each longitu-
dinal ridge on the trunk has four deep bends in it ; these deep
dents seem to connect crosswise, giving the appearance of five

BDELLOID ROTIFERA OF SOUTH AFRICA. 81

transverse rows of tiles or overlapping plates on tlie trunk. Ros-
trum very stout. Antenna short, about one-third neck width.
Teeth, 3/4. Foot of four segments. Spurs short, sharp with
wide, flat interspace. Corona slightly wider than collar. Upper
lip has a broad front margin with a gentle indentation. Size,
1/lOOth inch.

This little animal has a most extraordinary yet attractive
appearance. Viewed from the front and looking downwards,
the trunk seems protected with five transverse rows of tile-like
parts overlapping posteriorly. These parts are not excrescences,
or foreign to the trunk as in M. incrassata, but the true skin,
ridged and bent into these little oblongs, as is made apparent
by the alteration of their shape with every movement of the
body, especially when creeping. If looked at sideways, when the
animal is feeding horizontally, the dorsal crests and hollows can
be seen, and it can be noticed also that the borders of the crests,
instead of curving down gradually to form the hollows, suddenly
bend straight down or even backwards, causing the appearance,
already mentioned, of tiles overlapping. The top edges or rims
of the ridges are easily focused, and are of a glaucous green colour,
contrasting sharply with the grey between. These loops appear
also on the rump with a little variation, but of a permanent
character, and are triple in the anal segment.

M. macmillani is a fast creeper, with a short glide or slither
with each step ; and it feeds freely and quietly.

The rostrum is stout with a double lamella which stands out
clearly. The antenna is short and exceptionally broad at the
base. The jaws are not very large, are winged and have three
teeth in the one and four in the other. When the animal is creep-
ing, the neck shows quite a distinctive shape. There is a gradual
curve from the rostral to the dental segment, the narrowest part
being about half-way between.

The rump seems to have three divisions, but not very markedly
so, and it is somewhat doubtful what belongs to the anal and what
to the pre- anal segments, though probably the anal is very large
and consists of two of these apparent divisions. The intestine
and contractile vesicle are both large. The spurs are short with
a wide, flat interspace. There is a short foot of four segments,
and on the last segment there is a ring expansion, but not large
enough to show outside the ankle, as in M. petulans.
JouRN. Q. M. C, Series II.— No. 78. 6

82 W. MILNE ON THE

The corona is bold, and lias a sulcus rather wider than half
the disc, and the proportions of the corona, collar and neck are
to each other as 10, 9, 7.

The upper lip rises above the sulcus bridge, has a broad
front, with rounded corners and a shallow indentation in the
middle. There is a thick, short, fleshy tooth in the sulcus.

The trunk is stippled.

The egg is broadly oval, with round knobs somewhat like those
in P. flena, but more numerous — about fourteen.

Habitat. — Eock moss, Grahamstown. On the first occasion
when I found this species I saw only some three or four, and put
my notes aside, lest it should prove a freakish or unstable variant ;
but on a second occasion it was found in great numbers, and
frequently as many as a dozen were seen on a slide. It does not
seem, however, to be widespread, as out of the large number of
pieces of moss examined only one small piece on each of the two
occasions contained any.

Professor Macmillan, Grahamstown, sent me the moss on both
occasions, and I have named the species after him.

Bibliography.

1. GossE, P. H. : On the Structure, Functions and Homologies

of the Manducatory Organs in the Class Eotifera, Phil.
Trans., vol. cxlvi., pp. 419-452. 1856.

2. Milne, W. : On the Defectiveness of the Eye-spot as a

Means of Generic Distinction in the Philodinaea, Proc.
Phil. Soc, Glasgow, vol. xvii. pp. 134-145. 1886.

3. Janson, 0. : Versuch einer Uebersicht iiber die Rotatorien-

Familie der Philodinaeen. Bremen, 1893.

4. Bryce, D. : Further Notes on Macrotrachelous Callidinae,

Journ. Quekett Micr. Cluh, Ser. 2, vol. v., pp. 436-455.
1894.

5. Milne, W. : On the Function of the Water- vascular System

in Eotifera, with Notes on some South African Floscularia,
vol. xxxvi., pp. 118-127, Proc. Roy. Phil. Soc.^ Glasgow,
1905.

6. Bryce, D. : On a New Classification of the Bdelloid Eoti-

fera, Journ. Quekett Micr. Club, Ser. 2, vol. xi., pp.
61-92. 1910.

feDELLOID ROTIFEKA OF SOUTH AFRICA. 83

7. Murray, J. : Australian Rotifera, Journ. Micr. Soc, pp. 164-

174. 1911.

8. Murray, J. : Canadian Rotifera, Journ. Royal Micr. Soc,

pp. 285-297. 1911.

9. Murray, J. : Rotifera of New Zealand, Journ. Royal Micr,

Soc, pp. 573-583. 1911.

10. Murray, J. : Some African Rotifers, Journ. Royal Micr. Soc,

pp. 584-587. 1911.

11. Murray, J. : Bdelloid Rotifera of South Africa, Ann. Trans-

vaal Mus., Pretoria, vol. iii., pp. 1-19. 1911.

12. Harring, H. K. : Synopsis of tlie Rotatoria, U.S. Nat.

Mus., Bui. 81. 1913.

Description op Plates.

Plate 2.

Fig. 1. Monoceros falcatus, side view,
la. Monoceros falcatus, dorsal.
16. Monoceros falcatus, head, ventral.
Ic. Monoceros falcatus, jaws.
Id. Monoceros falcatus, toes and spur, ventral.
2. Didymodactylos carnosus, dorsal.
2a. Didymodactylos carnosus, corona.
26. Didymodactylos carnosus, spurs, and toe orifice.
2c. Didymodactylos carnosus, toes exserted.

Plate 3.

Fig. 3. Philodina grandis, dorsal, feeding.

3a. Philodina grandis, ventral, creeping.

36. Philodina grandis, jaws.

3d. Philodina grandis, rump, dorsal.

3e. Philodina grandis, jaws after treatment with potash.

3/. Philodina grandis, lamella and setae.

3gr. Philodina grandis, left side corona, more enlarged.

4. Philodina childi, dorsal.

4a. Philodina childi, corona.

46. Philodina childi, toes and spurs.

>>

J)

9)

84 W. MILNE ON THE BDELLOID ROTIFERA Of SOUTH AfRlCA.

Plate 4.

Fig. 5. Philodina fraelonga, dorsal, feeding.
5a. Philodina praelonga, dorsal, creeping.
56. Philodina praelonga, toes extended.

6. Philodina inopinata, dorsal, feeding.
6a. Philodina inopinata, dorsal, creeping.
66. Philodina inopinata, jaws.

7. Philodina acuticornis Murray, var. odiosa, dorsal.
7a. Philodina acuticornis Murray, var. odiosa, jaws.
76. Philodina acuticornis Murray, var. odiosa, toes extended.

8. Philodina rapida, dorsal.
8a. Philodina rapida, corona.

Plate 5.

Fig. 9. Philodina nitida, dorsal, feeding.
9a. Philodina nitida, dorsal, creeping.

10. Philodina nitida, var. decens, corona.

11. Philodina patula, dorsal, feeding.
11a. Philodina patula, dorsal, creeping.

12. Philodina proterva, dorsal, creeping.
12a. Philodina proterva, corona.

Plate 6.

Fig. 13. Philodina scahra, dorsal, feeding.

13a. Philodina scahra, spurs, dorsal.

136. Philodina scahra, spurs, side view.

14. Macrotrachela petulans, dorsal.

15. Macrotrachela cuthherti, dorsal.
15a. Macrotrachela cuthherti, corona.
156. Macrotrachela cuthherti, jaws.

16. Macrotrachela macmillani, dorsal, feeding.
16a. Macrotrachela macmillani, dorsal, creeping.

Where proportional numbers are given in the text, each unit
represents l/6000th inch.

Journ. Quekett Microscopical Club, Ser. 2, Vol. XIII., No. 78, April 1916.

JOURK. Q.M. C.

Ser. 2, Vol. XIII., PI. 2.

2a

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Bdelloid Rotifera of South Africa.

JOURN. Q. M. C.

Ser. 2, Vol. XIII., PI. 3.

3.

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J. Miln-t del. ad- rutt.

Bdelloid Rotifera of South Africa.

JOURN. Q. M. C,

Sei. 2, Vol. XIII., PI. 4,

Bdelloid Rotifera of South Africa.

JOURN. Q. M. C.

Set. "2, Vol. XIII., PI. 5.

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JOURN. Q. M. C.

Ser. 2, Vol. XJII., PI. 6.

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Bdelloid Rotifera of South Africa.

85

A SIMPLE TROUGH FOR POND >-IF;^v

By J. T. Cook.

{Read December 2Sth, 1915.)

Figs. 1, 2.

The little piece of apparatus figured below is intended for use
as a- trough for pond life, and is suitable for low powers. The

Fm. 1.

Fig. 2.

following details may enable any one so desirous of constructing
a number for himself. Take a glass slip, 3x1 in,, and cut it

86 J. T. COOK ON A SIMPLE TROUGH FOR POND LIFE.

in halves ; also a piece of hard wood, such as mahogany, f in.
thick, and from this cut a piece 6 in. long and 1 in. wide. Next
cut a shallow groove about | in. deep along one of the edges just
sufficiently wide to take the two pieces of glass. Then divide
the slip of wood into six sections, which will provide material
for three troughs. A small rubber ring, preferably square in
section, is placed between the glass slips in the position shown
in the figure, and the edges of the glass slips are then fitted into
the grooves in the edges of the square of wood, in such a way
as to hold the rubber ring in position and to render it water-
tight. Should the grooves be insufficiently wide to receive
the glass slips, they may be increased slightly in width by the
use of a flat file. The writer has kept specimens of pond life
in these troughs for many weeks simply by adding a small
quantity of fresh water every other day. The lower figure
represents a trough in which the glass slips used are 3 x IJ in.,
and by their use a larger trough is obtainable. Of course, in
this case the original slip of wood is 1| in. wide instead of 1 in.
as in the smaller size described above. They are only intended
for use with low powers up to say J in. ; but as much of the
work on pond life is done with 1-in. objectives, they will be
found very useful. The advantages of such a trough are found
in their extreme simplicity and cheapness ; any one can make
them, also they can be taken to pieces for purposes of cleaning
without any fear of breaking.

Joum. Queketl Microscopical Club, Ser. 2, Vol, XIII., No. 78, April 1916.

87

PROCEEDINGS

OF THE '

QUEKETT MICROSCOPICAL CLUB.

At the 510th Ordinary Meeting of the Club, held on October 26th,
1915, the President, Professor Arthur Dendy, D.Sc, F.R.S., in
the chair, the minutes of the meeting held on June 22nd were
read and confirmed.

Mr. Ernest Quarry Bilham was balloted for and duly elected
a member of the Club.

The President announced that for the present it had been
decided by the Committee to commence the business of the
Meetings at 7.30 p.m. instead of 8 o'clock. The Committee
will meet at 7 o'clock p.m.

The President paid tribute to the memory of the late Prof.
Edward Alfred Minchin, M.A., F.R.S., who was a former President
of the Club, and who died at Selsey on September 30th, 1915.

He stated Prof. Minchin was the most conscientious investi-
gator he had ever met. In the study of Spongology, his most
striking contributions were on the histology and embryology of
the Calcarea, especially those dealing with the triradiate spicules,
or rather spicule-systems, as he proved them to be. His most
important memoirs on Sponges were produced while he occupied
the chair of Zoology at University College, London. Before
resigning this chair and accepting the newly-created chair of
Protozoology in the University of London, and making his
headquarters the Lister Institute of Preventive Medicine, at
Chelsea, he visited Uganda as a member of the Royal Society's
Commission on Sleeping Sickness. His Introduction to the Study
of the Protozoa, published in 1912, will long remain the standard
treatise on this important subject. Besides being President of
the Club, he was also Vice-President of the Zoological Society,
and latterly Zoological Secretary to the Linnean Society.

A resolution of deep regret was passed by the members, who

88 PROCEEDINGS OF THE

also expressed their sincere sympathy with Mrs. Minchin in
her great loss.

Mr. A. E. Hilton then read a paper on the " Formation of
Sporangia of Stemonitis."

This form of Mycetozoa is one of the most abundant in the
world. It is easily recognised by the dark brown sporangia,
usually 1/2 to 3/4 in. high, generally crowded together on slender
black stalks.

In Stemonitis the stalk is continued upward as a columella
nearly or quite to the top of the sporangium. From this the
capillitium branches in all directions and surrounds the sporan-
gium with a surface network of extremely delicate meshes,
through which the spores finally escape. The specimen described
here was gathered last August, after the heavy rains, in Highgate
Woods, from an old tree stump, near the top of which appeared
an old black and leathery fungus with patches of milk-white
Plasmodium, which seemed to have oozed from the stump.

The paper was illustrated by sketches and photographs showing
the various stages of development and specimens of the same
were exhibited.

A vote of thanks was accorded Mr. Hilton for his description
of the interesting observations he had made.

The President said that being interested in the subject himself,
he was very anxious that some of his fellow members should
also be interested in the study of sponges, and with the idea of
awakening such interest, he proposed to give a series of short
addresses on the subject, and with a view of stimulating examina-
tion he proposed to bring some material to the meeting for
distribution amongst the members, and hoped they would have
a flood of light thrown on the subject of sponge spicules. He
had often thought that very much work was done in connection
with diatoms amongst the members, and he thought that if
some of the energy expended in this direction was put into the
study of sponge-spicules, some good results might follow. The
matter had been brought before the Committee, who had decided
-that at the next Ordinary Meeting of the Club the first of these
addresses should be given.

In the absence of the author through ill-health, the Hon.
Secretary then read a paper on " Five New Species of Rotifera,'*
by Mr. David Bryce,

QUEKETT MICROSCOPICAL CLUB. 89

They are all of the genus Habrotrocha, and are named : H.
insigniSy H, sylvestris, H. pavida, H. fiava, H. longula.

The President complimented Mr. Bryce on having added
five new species to the Bdelloid fauna, and a vote of thanks
was accorded him by the members for his paper.

At the 511th Ordinary Meeting of the Club, held on
November 23rd, 1915, the President, Prof. Arthur Dendy,
D.Sc, F.R.S., in the chair, the minutes of the meeting held on
October 26th were read and confirmed.

Messrs. Geo. W. King, John Geo. Bradbury and Arthur P.
Drake were balloted for, and duly elected members of the
Club.

A letter was read from Mrs. Minchin in acknowledgment of
the resolution of sympathy transmitted to her from the last
meeting.

Mr. W. R. Traviss exhibited and described a new adaptation
to Swift's well-known portable microscope. He stated that
from time to time various modifications had been effected in
the instrument, always keeping in view, however, the retention
of its portability. The latest was that of a binocular body.
This is effected in a very novel and ingenious manner, which
allowed the instrument to be folded up so that it required only
the same small leather case as the monocular. The eye-pieces
are of the usual Continental size. The draw tubes pull out
separately for adjustment to the different inter-pupillary distance
of the user's eyes, and are marked in millimetres, thus enabling
the distance to be registered for future reference. The Wenham
Prism is that known as the short body prism. He also exhibited
another prism which can be supplied for placing over the eye-
piece, which effects a more comfortable adjustment in some
cases, and by a slight rotation remedies a not uncommon defect
in observers' eyes, where there is a want of agreement in the
visual planes. Several members spoke with much approval of
the arrangement. Mr. Ainslie thought the instrument was a
very beautiful little thing, and congratulated Mr. Traviss on the
design. He especially praised the prism adjustment, which he
had found enabled him to use the binocular with great comfort,
and had no doubt that many who experienced a difficulty in

90 PROCEEDINGS OF THE

using a binocular would find it of great service to them. The
President proposed a vote of thanks to Mr. Traviss for bringing
the model to the notice of the meeting. This was carried unani-
mously.

The President then invited Vice-President D. J. Scourfield to
take the chair.

Prof. Dendy said he did not intend to give a formal lecture,
but hoped to give a series of short addresses, as opportunity
occurred, on sponges, especially from the point of view of micro-
scopists. Although sponges are undoubtedly animals, there is
some controversy as to their position in the animal kingdom.
Some have held that they are Protozoa ; in Germany they are
considered as a group of Coelenterates. Prof. Sollas styled
them " Parazoa." No doubt they form an isolated group,
and do not link on to any of the other groups very closely.
They have affinities with the Protozoa, but may be regarded as
taking a higher position. They form a large group ; it is im-
possible to say how many species there are, but it is an enormous
number, almost comparable to the insects in diversity of form
and structure. They are of particular interest because we can
trace out in them the lines of evolution, and he wished to treat
them from this point of view, especially as regards the spicules.
The Calcareous sponges include the simplest of all the types
(Leucosolenia). This is a tube whose wall is composed of three
layers. The outside one, called the ectoderm, is generally found
to be formed of flat cells ; these pavement cells may become
amoeboid. The inside layer — the endoderm — is the most
characteristic feature ; it is composed of collared cells. These
are in structure like the collared flagellate Protozoa — the
Choanoflagellata. Between these two layers is a stratum of
mesogloea with cells embedded in it, some of which secrete the
skeleton composed of the spicules which support the body. In
the Calcarea these are formed of carbonate of lime and are of
various shapes. In life a stream of water is taken in through
small pores in the body wall, and is ejected through the large
terminal opening or osculum. This stream is maintained by
the action of the collared cells. The water is swept out of the
gastral cavity, removing waste products, while the incoming
current brings in particles upon which the cells feed and also
oxygen for respiration. This is a very simple form, and com-

QUEKETT MICROSCOPICAL CLUB. 91

plication arises chiefly from budding and colony formation.
The degree of complication of the canal system may be taken
as an indication of the degree of evolution of the whole sponge.
An ordinary bath sponge is a more complicated organism and
it is impossible to say how many individuals it represents.
You cannot define individuality. Sponges may be divided into
five great groups : first, those with calcareous spicules, the
Calcarea ; second, those which have no skeleton at all, the
Myxospongida, very primitive forms ; third, the Triaxonida,
with skeleton composed of siliceous spicules having three
axes and six rays ; fourth, the Tetraxonida, with siliceous
spicules having four axes and four rays, radiating at equal
angles from the centre ; fifth, the Euceratosa, in which the
skeleton is composed of horny fibres and there are no spicules.
The spicules originate in mother cells. The mother cells
are found in the mesogloea, the substance between the ectoderm
and the endoderm. They are not always the product of one
cell only. There is a spicule which reaches the length of 3J
feet, and is of nearly the thickness of a lead pencil. One
mother cell could hardly give origin to this, and it is not known
how it arises. Siliceous spicules are formed of opal, secreted
by the protoplasm of the cell. They are arranged in a scattered
manner in the simplest cases. By reference to diagrams, it was
shown how from the primitive tetraxonid form with four rays
— like a calthrops — a great number of shapes are derived. One
ray may be elongated while the others remain short (triaenes) ;
three rays may be suppressed, leaving only one, which may
acquire a head. Many other varieties were described and illus-
trated by sketches and by large diagrams. In most sponges
the spicules are divided into two categories, skeleton spicules
(megascleres) and flesh spicules (microscleres). Flesh spicules
are of interest because it is so difficult to conjecture what can
be their use. They are very beautiful and constant in form.
A great number of shapes were pointed out on the diagrams,
the method of their origin from simpler forms being described
and illustrated on the blackboard. Prof. Dendy had brought
for distribution among the members a tube containing a sponge
from the Indian Ocean — Dercito'psis minor — ^which would afford
interesting examples of some of the more primitive tetraxonid
spicules.

92 PROCEEDINGS OF THE

At the invitation of the Chairman many of the members
asked the President questions on various points, to which he
replied. Mr. Scourfield said the President had given them a
most interesting communication, and the study of the material
would afford them plenty of work. Such a paper was quite a
new feature in the proceedings of the Club, and a very welcome
one. He proposed a very hearty vote of thanks to the President,
which was carried by acclamation.

At the 512th Ordinary Meeting held on December 28th, Vice-
President C. F. Eousselet, F.R.M.S., in the chair, the minutes
of the meeting held on November 23rd were read and confirmed.

Mr. John Syer was balloted for and duly elected a member
of the Club.

After the usual preliminary business had been gone through,
Mr. J. T. Cook exhibited a novel form of trough for pond life
which he had designed, and from considerable use had found
very successful. It may be made of almost any size that is
desired, but dimensions that can be constructed from the ordinary
3 X 1 in. slips are advantageous, as every microscopist has these
at hand. Two slips should be taken, and between them an
indiarubber ring, such as is used for putting round papers, etc.,
should be enclosed. It may be left entire with a part projecting
above the top of the slips, or a segment can be cut of a suitable
size which will lie wholly within their breadth. The ends of
the slips are then clipped together by a piece of hard wood,
about 1 in. square, in which a groove had been cut of the requisite
width to hold together the glass slips and put some slight amount
of pressure on the rubber ring, and so prevent leakage. Obviously
the ring may be of greater or less thickness, thus varying the
capacity of the water space from front to back, while a broad
or narrow space can be obtained by its adjustment to suit the
purpose in view. Mr. Cook showed a variety of sizes, with differ-
ent shapes of internal construction. He stated that among
the advantages of this trough are that they are so simple that
any one can make them ; cheapness — the cost of the materials
being altogether negligible ; ease of cleaning — the only requisite
being to slip ofE the wooden clips, when the glasses can be wiped,
and all replaced with a minimum of trouble ; and, perhaps

QUEKETT MICROSCOPICAL CLUB. dS

greatest of all, their ready construction of any suitable form and
size for the requirements of a particular case. The only part
to wear out is the rubber ring, and that will last a considerable
time. Mr. Cook had frequently had a trough in use for many
weeks, containing organisms whose development he wished to
watch. Several members spoke in appreciation of the advan-
tages of the little apparatus, and a hearty vote of thanks was
passed to Mr. Cook for bringing it before the meeting.

Mr. Burton then read a short paper, " Notes on the Aleurodes
Fly." The Cambridge Natural History definition of the family
is, " Minute insects with four mealy wings, seven-jointed antennae,
two-jointed feet, terminating in two claws and a third process."
Mr. Burton said the subject was not quite new to the members,
as Mr. R. T. Lewis, in 1895, described and figured a new species
that had been sent to him from Natal. It was named Aleurodes
asparagi, having been found on plants belonging to the genus
Asparagus in Natal. The paper was a most useful one, and
gave more detail than any other with which he was acquainted.
It will be found in the Quekett Microscopical Club Journal, vol. vi.,
second series.

Mr. R. T. Lewis said, with reference to the destruction of a
pest by the introduction of its enemies, a case in point occurred
in connection with the notorious Icerya purcJiasi, which, having
been introduced into South Africa, had affected the orange
and lemon trees over a district of 800 square miles. Laws were
passed requiring infected trees to be cut down and burnt ; but
the inhabitants, whilst they cut them down, dragged them through
the villages for firewood, and so distributed the insects still
further. The discovery of the male determined that it was
the Australian species which had been imported, and, finding
that in Australia the Icerya was kept down by a species of
Rodolia (one of the Lady- bird tribe), large numbers of these
insects were imported, and now the pest was reduced to manage-
able limits.

A vote of thanks was passed by the members for Mr. Burton's
paper and interesting exhibits.

At the 513th Ordinary Meeting, held on January 25th, 1916, the
President, Prof. Arthur Dendy, D.Sc, F.R.S., in the chair, the

94 PROCEEDINGS OF THE

minutes of the meeting held on December 28th were read and
confirmed.

Mr. Theodore Stephanides was balloted for and duly elected
a member of the Club.

A list of the officers nominated bv the Committee for the
coming year was read. As far as possible they were the same
as in 1915, with Prof. Dendy again President. This announce-
ment was received with marked satisfaction by the members
present. Nominations for filling the vacancies in the Committee
were then made. Mr. Grundy was proposed by Mr. Wilson and
seconded by Mr. Beston ; Mr. Gabb was proposed by Mr. Rous-
selet and seconded by Mr. Brown ; Mr. Paulson was proposed
by Mr. Sheppard and seconded by Mr. Bryce ; Mr. Soar was
proposed by Mr. Perks and seconded by Mr. Grundy ; Mr.
Ainslie was proposed by Mr. Watson-Baker, Jr., and seconded
by Mr. Offord.

The President said he regretted to have to announce the
recent death of one of their members. Mr. G. K. Dunstall
joined the Club in 1910, died on January 9th. He was chiefly
interested in Rotifers.

It was moved by Mr. Wilson and seconded by Mr. Bryce
that a vote of condolence be sent from the club to Mrs. Dunstall.
This, having been put to the meeting by the President, was
unanimously agreed to — all standing.

The hon. secretary read a paper by Mr. G. T. Harris, of Sid-
mouth, " On the Collection and Preservation of Desmids." The
paper referred to the frequent complaint of the uninitiated of
their lack of success in obtaining desmids. It was remarked
that this was probably due rather to the method of collection
than to any actual scarcity in the objects. Their presence in
various situations was noted, and the fact that the ordinarv
ring-net, as used by collectors of microscopic organisms, was not
well fitted for use in many of them. Prof. West's suggestion of
clipping the stems of aquatic plants under the surface of the water
between the closed fingers and drawing the hollowed hand carefully
up, making of it a cup in which the flocculent matter is caught, was
approved of. If the collecting excursion is of a day's duration
only, the ordinary supply of tubes and bottles will suffice, and
the material may be brought home in the water in which it
was found. If the excursion is more extended, however, the

QUEKETT MICROSCOPICAL CLUB. 95

number of tubes and bottles required becomes inconvenient
and subject to disaster by breakage. Under these circumstances,
therefore, the author had adopted the plan of killing and fixing
the desmids where they were collected, and he had found this
quite satisfactory. The method is as follows : A small funnel
to support filtering material is essential. It was found that the
best material for the filter was chamois leather, which has the
advantage that it allows of the residue left, after the water
has run off, being scraped up with a spatula without risk of
tearing the filtering material. The filtered residue may then
be placed in tubes (3-in. by 1-in. is a convenient size), each
numbered to correspond with notes giving the name of the
locality and the habitat, as bog, moor pool, pond, etc., with any
other desired particulars. When what is deemed a sufficient
amount has been placed in the tube, this should be nearly filled
with clear water and about 4 cubic centimetres of the following
killing and fixing solution should be added :

Cupric sulphate (10 per cent, solution) . . , 100 c.c.

Mercuric chloride (saturated solution) ... 10 c.c.

Extreme accuracy in the quantity added is not necessary,
and a little practice soon enables one to estimate the right amount.
The only drawback connected with this method of treatment is
that the material is apt to become too concentrated. Care,
therefore, should be taken not to place too much in a tube.
As in about 10 cubic centimetres of filtered material obtained
from one small unimportant bog over one hundred species and
varieties of desmids were found, it is obvious that this is a very
practical and productive method. Large, old-established bogs
yield the best results, both as to individuals and species, and
bogs which form during the winter and dry up in the summer
should be avoided ; they are seldom remunerative. Moorland
pools are always w^orth the collector's attention, and often yield
quite different species from those of the bogs. A feature that
strikes one in connection with them is that often they are occu-
pied almost exclusively by one, or at most a very few, species.
One moorland pool examined on Dartmoor was so filled with
Staurastrum hrachiatum that from every part of it the net was
crowded with specimens, and another small pool was quite
green with the rod-like threads of Hyaloiheca dissiliens, and

96 PROCEEDINGS OF THE

practically nothing else occurred there. Yet another pool was
the exclusive preserve of Xanthidium variahile.

The paper was greatly appreciated for its practical and useful
character, and at its conclusion considerable discussion took
place, in which Messrs. Wilson, Scourfield, Brown, Gabb, and
others joined. Mr. Burton, who had had some experience in
mounting desmids, while admiring greatly the perfection with
which Mr. Harris had preserved the natural colour of his speci-
mens, expressed a preference for staining methods which, if
successful, differentiated the tissues more distinctly than the
other. At its very best the natural colour could only be retained
in the chloroplast, where alone it existed, leaving the rest of the
specimen undifferentiated. He also feared as to the lasting
powers of mounts in somewhat deep cells where the medium was
practically water only, which always sooner or later acted on
the cement. In his own mounts, which were in glycerine, he
endeavoured to employ as dense a fluid as it was possible to use
without contracting the protoplasm. A hearty vote of thanks
was passed to Mr. Harris for his interesting and useful paper.
A number of specimens of desmids mounted by Mr. Harris in
the way described were exhibited under microscopes on the
table, and were greatly admired, especially for the beautiful
way in which the natural colour was preserved.

At the 514th Ordinary Meeting, which was also the fiftieth
Annual Meeting, held on February 22nd, the President, Prof.
Arthur Dendy, D.Sc, F.R.S., in the chair, the minutes of the
meeting held on January 25th were read and confirmed.

Messrs. Charles H. Bocock and J. J. Jackson were balloted
for and duly elected members of the Club.

A series of micro, objects were exhibited by Mr. W. E. Watson
Baker to illustrate the results of some new mounting methods.
In view of the President's recent addresses on sponge spicules,
three specimens, viz. : A type slide of sponge spicules, a group
of sponge spicules from St. Peter, Hungary, and a section of
Euplectella mirahilis were exhibited. The first two are rather
rare, the mounter having died some years ago, and no one having
taken up the work since. A slide of an unusually perfect specimen
of Filaria nocturna, stained with Giemsa and mounted in neutral
balsam, which displayed the details of the object remarkably

QUEKETT^MlCROSCOPICAL CLUB. 97

distinctly, was shown. There were three slides of test diatoms,
Pleurosigma sinense and Nitzschia rahenJiorstii to illustrate a new
arrangement in which the longitudinal and transverse striae of
each specimen are counted and marked on the slide. By this
means it is hoped to standardise the use of these objects for
testing objectives. Another was a type slide of sixty-four
specimens from a deposit at Atlantic City, New Jersey. It had
been found that specimens of the same species from different
localities showed a variation in the fineness of the markings.
In order, therefore, to get a record of any variations from
these localities, a series of slides was being collected and
mounted, which it was hoped would be of particular value to
diatomists. Mr. Baker stated that, since the death of Mr. Elcock,
of Belfast, he did not know of any professional mounter of
Foraminifera type-slides except Thum, of Leipzig. Recently,
however, an English mounter had taken up this work, and two
of his slides, one of thirteen and the other of thirty-two species,
were exhibited. These were much admired for the perfection
and cleanness of the specimens. The special mount in which
they were put up allowed them to be taken out for photographic
use, and they could be examined without a cover-glass, thus
overcoming entirely the reflection from the cover which is so
often troublesome. At the suggestion of the President, a hearty
vote of thanks was accorded to Mr. Watson Baker for his exhibit
and interesting remarks respecting the specimens.

The special business of an annual meeting was then proceeded
with. The President requested two members to act as scrutineers,
and the ballot was taken for the officers, and to complete the
number of the Committee after the annual retirement. The
result was announced later, as far as possible those appointed
being the same as previously. The Hon. Sec. read the Com-
mittee's report, which disclosed a very satisfactory condition
notwithstanding the many difficulties caused by the war. In
spite of the darkened streets, the restricted means of conveyance,
and the large number of the younger members engaged in military
matters, the attendance at the meetings was only slightly less,
while there was even a small increase in the list of members.
The reports of the Librarian, the Secretary of the Excursions
Sub-Committee, and the Curator were all good. The Treasurer's
balance-sheet, though obviously affected adversely by the war,

JouRN. Q. M. C, Series II.— No. 78. 7

^8 PROCEEDINGS Ot* TSE QUEKETT MICROSdOPICAL CLUfi.

and by some unusual expenses, was perfectly satisfactory. These
were all adopted and passed by the meeting.

After requesting Vice-President D. J. Scourfield to take the
chair for the occasion, the President then delivered his annual
address, which was entitled " Some Factors of Evolution in
Sponges." It dealt largely with the development of the spicules
in the various classes of sponges, and necessarily was of a dis-
tinctly technical character. At its conclusion the Chairman,
after some comments on the value and interest of the address,
requested the President to allow it to be printed in the Journal^
and proposed a vote of thanks to him. This was accorded by
acclamation by those present. Prof. Dendy cordially gave his
consent to the request, and resumed the chairmanship of the
meeting. A vote of thanks to the scrutineers of the ballot and
to the auditors of the balance-sheet was proposed and carried ;
as was also the same to the Officers and Committee, with some
appreciative remarks on the care and hard work that must have
been requisite to produce such satisfactory results during the
difficult period of last year. The Treasurer, Mr. F. J. Perks,
made an appropriate reply.

The President then read out the result of the ballot for Officers
for the ensuing year :

As President

• •

As Four Vice-Presi-
dents.

As Treasurer

, Secretary .

, Foreign Secretary

, Reporter .

, Librarian

, Curator .

, Editor

As Five Members of
Committee.

Prof. Arthur Dendy, D.Sc, F.R.S.
fC. F. Rousselet, F.R.M.S.

D. J. Scourfield, F.Z.S., F.R.M.S.
IE. J. SpiTTA.,L.R.C.P.,M.il.C.S.,F.R.A.S.
VDavid Bryce.

Frederick J. Perks.

James Burton.

C. F. Rousselet, F.R.M.S.

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

S. C. Akehurst, F.R.M.S.

C. J. SiDWELL, F.R.M.S.

A. W. Sheppard, F.Z.S., F.R.M.S.
fC. D. Soar, F.L.S., F.R.M.S.

R. Paulson, F.L.S., F.R.M.S.

G. H. Gabb, F.C.S.

M. A. AiNSLiE, R.N., B.A., F.R.A.S.

Jas. Grundy, F.R.M.S.

99

FIFTIETH ANNUAL REPORT.

Your Committee in making their Eeport for the year ending
December 1915 may be allowed to remind members of the many
difficulties and drawbacks that have been encountered owing to
the continuance of the war. Taking these into consideration,
they feel justified in congratulating the Club on the results which
have been achieved. Twenty-three new members have been
elected, sixteen have resigned, and five have been lost through
death, giving a net increase of two, and a total membership of
449. The number elected and the total increase are considerably
below those of recent years, but nothing else could be anticipated
in the circumstances.

Having regard to the darkness of the streets, the lessened means
of conveyance, and the quite reasonable reluctance of many to be
absent from home after dark, owing to the possibility of air raids,
and also to the fact that a considerable number. of members are
at the front, or engaged on Government work, it might have
been expected that the attendance at the meetings would be
seriously affected ; and it is most encouraging to find, on com-
paring the numbers present during the past year with those of
1913, that the reduction in numbers attending the Ordinary
Meetings has amounted to an average of eight only ; and the
attendance on the Gossip nights has been an average of only six
less than in 1913.

The Club has to deplore the death of Past-President Prof.
E. A. Minchin. His last lecture was given in January, and was
accompanied by a gift of mounted specimens. He was present
at the Annual Meeting in February, and took the chair while
Prof. Dendy delivered his Presidential Address ; this was his last
evening with us. An obituary notice and portrait appeared in
the Journal for November.

In February the death of Mr. F. W. Millett took place. He was
one of the original members, having joined in July 1865. Owing

100 FIFTIETH ANNUAL REPORT.

to his residence in Cornwall and his advanced age (he was in his
eighty-second year at the time of his death), he had not been
able to attend the meetings for a long time. An obituary notice
appeared in the April number of this Journal. In June the death
of Mr. G. Yogeler occurred ; he had been an active member of
great assistance, especially in the Curator's department. A former
member, Mr. B. AV. Priest, died in September ; he had not been
to the meetings for many years, but with a kindly remembrance
has bequeathed a collection of sponge preparations to the Club.
The papers and exhibits during the year were as follows :

Papers and Exhibits during 1915.

January 2Wh. — Prof. E. A. Minchin : Notes on the Anatomy of
the Eat Flea — Ceratophyllus fasciatus.

February 23/y7. — The President : The Biological Conception of
Individuality.

March 23rrf. — C. D. Soar : British Hydracarina — Genus Lehertia.

March 2Srd.—J. AV. Gordon : A " New " Object-glass by Zeiss.

March 23rcf. — G. T. Harris : Microscopical Methods in Bryo-
logical Work.

April 21th. — M. A. Ainslie : An Addition to the Objective.

April 27th.— A. A. C. Eliot Merlin : Notes on Diatom Structure.

May 26th. — J. Grundy : Exhibit — A Fly's Wing, showing crystals
formed in the mountant.

May 26th. — A. E. Hilton : Further Notes on the Cultivation of
Badhamia utricularis.

May 2bth. — E. M. Nelson : Various Insect Structures.

May 26th. — J. Burton : Hydrodictyon utriculatum.

May 26th. — Seabury Edwards : On mounting Diatoms in Phos-
phorus.

June 22nd. — Dr. John W. Evans : The Microscopical Examina-
tion of Minerals.

October 26/A. — A. E. Hilton : The Formation of Sporangia in
Stemonitis.

October 26M. — D. Bryce : Five New Species of Bdelloid Rotifers.

November 2?>rd. — W. R. Traviss : Exhibit — A Binocular Addition
to Swift's Portable Binocular.

November 2?>rd. — The President : On Sponges, General Structure,
and Spicules.

FIFTIETH ANNUAL REPORT. 101

Deccmher 2Sth.—J. T. Cook : Exhibit— A New Form of Trough

for Pond Life.
Decemhcr 28th. — J. Burton : Notes on a Species of Alcurodes.

Your Committee wishes to thank the authors on behalf of the
members for these interesting communications.

The Fiftieth Anniversary of the foundation of the Club occurred
in June. It had been intended to mark the event by some cele-
bration, but it was felt by many that in the circumstances of the
war such a course would not be appropriate. The President at
the Ordinary Meeting on the 22nd, however, called the attention
of the members to the event ; a full account of the proceedings
appears in the Journal for November. In November the Presi-
dent gave an address on Sponges — the first of a series of short
addresses which he is kind enough to propose to deliver at inter-
vals during the session. Material for distribution, that the
members might follow out the subject by making their own pre-
parations, was also provided by Professor Dendy. The Gossip
Meetings have not only been well attended, but there has been
almost no diminution in the number of objects of interest ex-
hibited, and in the enthusiasm of those displaying and explaining
them. The Committee thank those who, often at considerable
personal trouble, have done so much to render these meetings a
success ; and would press upon all those able to do so the desira-
bility of their taking part in the good work.

The new catalogue of the Library issued to the members in
1915 has no doubt helped to maintain and increase an interest in
the Library, with the result that 160 volumes have been issued to
the London members, during the year. The arrangements made
to post books to country members have not been taken advantage
of, only one application having been received since the scheme
came into force. To give members an opportunity of ready access
to those books, available for reference only, a selection of such
works has been placed on the table on Gossip nights for examina-
tion, and this arrangement, which has been much appreciated,
will be continued in the future.

102 fiftieth annual report.

List of Books Purchased and Presented from January

1915 TO January 1916.

Purchased.

A Monograph of the British Marine Annelids. By Prof.
W. C. Mcintosh. Vol. iii., pt. 1. Text. Polychaeta.

iVPHELIIDAE to AmMOCHARIDAE. 1915.

IcoNES Plantarum Asiaticarum, Part I. 1847.
Handbook of Photomicrography. By H. Lloyd Hind and
W. Brough Randies, 1913.

Presented.

Les Diatomees du Monde entier. By J. Tempere and H.
Peragallo, 2nd ed., 1915.

American Hydroids. By C. C. Nutting. (Smithsonian Insti-
tute. Special Bulletin.)

Miscellaneous Papers on Eotifera. By C. F. Rousselet.

Reports of the Clare Island Survey, Proceedings of the
Royal Irish Academy, vol. xxxi.

Elementary Photomicrography. By W. Bagshaw, 3rd ed.,
1915.

Contributions a l'etude des Rotateurs du Bassin du
Leman. By G. Montel.

List of Periodical Publications Received for the Year

ENDING December 1915.

Academy of Natural Science, Philadelphia.

American Microscopical Society.

Bergen Museum.

Botanical Society of Edinburgh, Proceedings and Transactions of.

California, University of.

Geologists' Association, Proceedings of.

Glasgow Natural History Society.

Hertfordshire Natural History Society, Trans, of.

Indian Museum, Calcutta.

Manchester Literary and Philosophical Society.

Manchester Microscopical Society, Trans, of.

Micrology, The Journal of.

Microscopical Science, Quarterly Journal of.

Fiftieth annual report. 103

Missouri Botanic Garden.

Nyt Magazine.

Philippine Journal of Science.

Redia.

Royal Institution of Great Britain, Proceedings of.

Royal Microscopical Society, Journal of.

Royal Society of London, Proceedings of. B Series.

Royal Society of New South Wales.

Smithsonian Institute.

Victorian Naturalist.

Wisconsin Academy.

During the year twelve excursions were held, the average
attendance was 17*6 ; this is very good when the number of our
members serving their country abroad or at home is taken into
consideration. The difficulty of finding suitable localities for
the Saturday afternoon excursions was increased by some cur-
tailment of excursion trains, as well as by the fact that owing to
war conditions it was not possible to visit the East London Water
Works or the Surrey Commercial Docks. The excursion to
Northolt and Ealing under the guidance of Mr. Offord was highly
successful, and a very pleasant outing was brought to a close by
the kindness of Mr. and Mrs. Offord in entertaining the members
to tea at their house. We were indebted again to Sir Philip
Sassoon for permission to visit the private waters in Trent Park,
and to the Royal Botanic Society for their usual kindness in
allowing us to visit the gardens in Regent's Park.

The Curator reports that a larger number of slides has been lent
than during the previous year, and 173 preparations have been
added to the Cabinet. The principal of these are twenty-four
beautiful and instructive dissections of the Rat Flea, kindly given
by the late Prof. Minchin, which, in conjunction with a reprint
of his paper, are available for borrowing as one of the descriptive
series. A welcome addition was the donation of seventy-seven
slides of Mosses from Mr. G. T. Harris, which should prove
valuable to any member taking up the study of this interesting
family. Another addition has been the purchase of a type-
collection of forty slides of Palaeobotany, prepared by the well-
known expert, Mr. Lomax. These are remarkably fine speci-
mens, and the majority of them are described and illustrated in

104 FIFTIETII ANN'UAL REPORT.

Dr. Scott's Studies in Fossil Botany, a copy of which work is in
the Club's Library. The gift by Mr. Huish of a small set of
preparations of Mycetozoa has also filled a gap in the cabinets.
The Committee tenders its best thanks to Mr. Bestow for the
assistance he has given to the Curator in the issue of slides and the
work of the Cabinet, and to Mr. Todd, who as Assistant Librarian
has been full of energy in the work of the department. Also to
Mr. L. C. Bennett, who has been of the greatest service in making
visitors welcome and in introducing them and those newly elected
to the other members, and in thus promoting the social spirit
and friendliness for which the Club has always been notable.
Thanks are due to Mr. Robotham, who as Assistant Secretary has
supplied excellent reports of the meetings to the English Mechanic
on many occasions.

The Committee wishes once again to express their thanks, and
those of the general body of members, to the various officers for
their care and often hard work in conducting the affairs of the
Club with such efficiency during the trying period of last year.

Finally, they would call upon all if possible to increase their
efforts for continued success, by attending the meetings as often
as they can, by bringing a microscope with objects for exhibition
whenever possible ; and especially by making a communication
and taking part in any discussion at the Ordinary Meetings, and
by introducing the Club to the notice of anyone among their
friends who is likely to join it.

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JouRN. Q. M. C, Series II. — No. 78.

8

The late Richard Tho3ias Lewis, F.R.M.S.

faetat. 54.')
Frontispiece] [See page 201

107

THE SECONDARIES OR DOTTED STRUCTURE IN

PINNULARIAE.

By Chapman Jones.
{Read April 25th, 1916.)
Communicated by A. Morley Jones.

Plate 7.

About forty-five years ago Mr. Henry J. Slack contributed a
note to the Royal Microscopical Society * in which he remarks
that " at one time it was supposed that the Pinnulariae were
distinguished from allied forms by solid costae replacing beaded
bands," but " more recently this distinction has not been deemed
valid." He continues that " an examination of the Pinnulariae
on Moller's type-slide led to the belief . . . that instead of
broad irresolvable ribs, a truer view " of the costae " exhibited
fine lines of beads springing from the median band, with a furrow
between them, and in that furrow another line of beads at a
lower level." Mr. Slack obtained from Moller a series of Pinnu-
lariae mounted dry, and examined them by means of " a re-
markably fine immersion l/8th by Powell & Lealand on their
new system. The condenser employed is a 4/lOth one of Ross,
and the usual stop, one radial slot, aperture 109°. The most
serviceable eyepieces were C and D of Ross's scale." The twelve
species examined all showed, though some with much difficulty,
" the composite character of the so-called costae."

Quite recently, Mr. T. A. O'Donohoe f has produced a photo-
graph of a Pinnularia nobilis which shows excellently the presence
of a dotted structure. He used annular illumination and a
2 mm. apochromat. But in spite of these results, and perhaps

* The Monthly Microscopical Journal, xxxii., August 1871, p. 71.
I Journal of the Quekett Microscopical Club, April 1914, p. 309.

JouRN. Q. M. C, Series II.— No. 79. 9

108 CHAPMAN JONES ON THE SECONDARIES OR

other work on this subject, the nature of the dotted structure
and the reason for its elusive character do not appear to be
known. Having among my slides of Pinnulariae one in which
the valves have suffered much both mechanically and from
corrosion (I suppose in cleaning the material) I have searched for
information on these points.

I think that the photographs that I have the honour of laying
before the Club, as well as the examination of many other speci-
mens on other slides as well as this particular one, lead to the
following conclusions :

1, That finding the dots is not a matter of resolution as
ordinarily understood, but rather of rendering them more
conspicuous, except perhaps in some of the smaller valves.
The dots in Mr. O'Donohoe's photograph are of about the
same order of coarseness as those of Surirella gemma, and this
diatom cannot be called a very difficult one to resolve. I have
measured them as well as I can from the reproduction of his
photograph and find that their distance apart is equivalent to
from 60 to 70 thousand to the inch. The dots in the specimens
I have examined are not uniformly distanced in any one case.
In figure No. 1, which represents a part of a large valve, they
range from 32 to 40 thousand to the inch ; in figure No. 2, which
is a rather small valve, 50 to 70 thousand to the inch ; in the
other figures from 43 to 46 thousand. High-power dry objectives
of ordinary apertures have therefore quite sufficient " resolving "
power.

2. That the dots are not immediately connected with the
costae as Mr. Slack and others appear to have assumed.

3. When viewing a valve in the ordinary way, that is, with its
outside or convex side uppermost, it appears that there is a
dotted membrane under the costae, and a non-dotted if not
structureless membrane over the costae, and that the dots are
generally hidden by this upper membrane, unless special means
are taken to render the dots conspicuous.

4. This dotted membrane appears to be attached, at least in
some cases, to the girdle. This accounts for its absence from
some valves. On the other hand, it is sometimes attached to the
costae. Perhaps there is a strip of dotted membrane attached

DOTTED STRUCTURE IN PINNULARIAE. 109

to or forming a part of the girdle, and other dotted membranes
attached to the costae, but I have no direct evidence of this.

5. That the dots are concavities, as one might expect by
analogy, because fracture takes place across them, and when
seen sideways on the rounded edge of a curved membrane the
curve of the concave outline is obvious.

The photographs were all taken with a 2 mm. Holos. objective,
N.A. 1'36 ; X 8 compensating eyepiece ; a Holos. immersion
condenser diaphragmed down to N.A. TO, except for oblique
light, then at full aperture of N.A. 1'38 ; and with green light.
The specimens are mounted in "realgar."

Fig. 1. Pinnularia nobilis, x 1,300. Illuminated with a solid,
central cone N.A. 1*0. This shows dots through the costae and
along the whole length of each costa as far as the focus allows.
There is also evidence of out-of-focus structure between the
costae.

Fig. 2. P. nobilis, x 1,200. A much smaller valve than above,
and one that shows no trace of structure with central light. A is
focused for a slightly lower plane than B. Doubly oblique light.
The dots are clearly visible along the whole length of the costae,
as the focus permits, and also between them. The dots are
veiled, I suggest by the membrane that lies over the costae,
and to a certain extent confused by the material that they have
to be seen through.

Fig. 3. P. viridis, x 1,280. Illuminated with a solid central
cone, N.A. TO. The upper membrane here is missing in parts,
and where it is missing the dots show through the costae and also
between them.

Fig. 4. Part of a valve with its inner or concave surface upper-
most, X 1,250. Illuminated with a solid central cone, N.A. TO.
Portions of dotted membrane are adhering to the upper (really
the inner as regards the frustule) edges of the costae.

Fig. 5. These appear to be detached costae showing their
side faces, x 1,250. Illuminated with a solid central cone,
N.A. I'O. They show no sign of dotted structure.

Fig. 6. A detached strip of dotted structure, x 1,200. Illumin-
ated with a solid central cone, N.A. TO. The whole length of
the strip, only part of which is shown, agrees with the length of

110 CHAPMAN JONES ON THE SECONDARIES IN PINNULARIAE.

the Pinnulariae near it, and I do not find anything else on the
slide of which it might be a part.

A seventh photograph was exhibited, showing a girdle, x
1,250. Illuminated with a solid central cone, N.A. I'O. The
dotted membrane at the margin of the girdle is curved round
to approximately a right angle to the face of the girdle, so that
this might project into the frustule and thus lie under the
costae. Girdles like this are not rare.

Journ. Quckctt Microscopical Club, Ser. 2, Vol. XIII., No. 79, November 1916.

Jotjr:n. Q. M. C.

Ser. 2, Vol. XIII., PL 7.

The Secondaries of Finnulariae.

Ill

ON NITZSCHIA SINGALENSIS AS A TEST-OBJECT
FOR THE HIGHEST POWERS.

By a. a. C. Eliot Merlin, F.R.M.S.

{Read April 25th, 1916.)

Plate 8.

I AM indebted to the kindness of my friend Mr. E. M. Nelson for
a styrax mount of this very interesting diatom from Amherst,
Burma. Its minute structure is undoubtedly of a similar nature
to that of other and coarser varieties of the genus, but although
the form is large, the structure is so fine that hitherto only the
transverse striae have been seen by their discoverer, Mr. Nelson,
and up to the present most other microscopists have failed to
see them. Under these circumstances the photograph (PI. 8)
taken with a l/8th apochromat of 1*42 N.A. at a magnification of
3,600 diameters by means of oblique sunlight from a heliostat,
which clearly reveals the transverse striation, will, I venture to
think, prove of interest to many members of our Club, which
has done so much in the past in an unpretentious way to en-
courage advancement in all matters appertaining to the micro-
scope.

At present many of us must feel that our old friend Amphi-
fleura pellucida can no longer claim the proud position which it
so long held as the test for objectives of the highest power. As a
matter of fact, for many years past, any tolerable oil-immersion
lens of moderate aperture could be relied upon to reveal easily
its once elusive transverse striae (which run at from 93,000 to
100,000 to the inch) by means of oblique light. Keally good
objectives of 1*3 N.A. will reveal them in balsam without any
great difficulty with axial illumination, and I have photographed
clearly striae at 95,000 to the inch in a realgar preparation of
A. pellucida with central light from the edge of the lamp flame.

112 A. A. C. ELIOT MERLIN ON NITZSCHIA SINGALENSIS.

Thus the conscientious microscopist can no longer feel that he is
accomplishing anything requiring great manipulative skill when
he obtains distinct rendering of the transverse striae of an average
A. pellucida, although of course to show the dotted structure is a
far more difficult task.

With the Nitzschia singalensis the case is different, and any
microscopist who can clearly reveal the transverse striation may
justly feel satisfied with his optical appliances. I endeavoured
to count visually the striae by " stepping " with the cobweb
micrometer in the usual way, and noted 116,000 to the inch as
the result, but owing to their faintness the eye became rapidly
fatigued, and I could not feel any great confidence in the accuracy
of the count. Another and more certain method is available,
and the magnification at which the photograph (PL 8) was
taken was verified as exactly 3,600 diameters by the projection
of Grayson's rulings on to the camera screen with the precise
optical combination and camera extension used to obtain the
photograph. Now the striae on the photograph run at 32 to the
inch, which multiplied by 3,600 makes them 115,200 to the inch.
This may be relied upon as correct for the specimen photo-
graphed.

In practice I have found that the transverse striae of N.
singalensis can be revealed with a good semi-apochromatic
objective of 1*33 N.A. by means of axial light and a Gifford screen ;
and I should here like to record my conviction, as the result of
long experience, that a really well corrected and fine objective
will resolve fully as much with axial as with oblique light, although
it may need less skill and less keen sight when employing the
latter method. I also venture to suggest that, as a test for first-
rate objectives of the largest aperture, Nitzschia singalensis
must henceforth rank far above A. pellucida, and any failure
to resolve the transverse striae of the former with lenses of
1*30 N.A. and upwards will indicate a faulty objective or faulty
manipulation. Nevertheless, the test is severe, and when accom-
plished with axial light requires good eyesight in addition to good
optical means.

JOURN. Q. M. C.

Ser. 2, Vol. XIII., PI. 8,

NiTZSCHIA SINGALENSIS,

113

NITZSCHIA SINGALENSIS ! A NOTE ON MR.
MERLIN'S PAPER.

By M. a. Ainslie, R.N., B.A., F.R.A.S.

(Read April 25th, 1916.)

It has long been recognised that as a test for resolution, at any
rate with oblique light, our old friend Amphipleura 'pellucida
leaves something to be desired ; as Mr. Merlin says, the exhibition
of its transverse striae is no great feat at the present day.

I am inclined, however, to think that no resolution, even of
the most difficult diatom, when performed by means of oblique
light, affords any real criterion of the excellence of an objective ;
indeed, I have heard it whispered that at one time it was not an
uncommon practice with some opticians to correct their immersion
objectives to give the best possible resolution with oblique light,
without much attention being paid to the correction of the central
and intermediate zones, which would be more useful for general
purposes. So long as their customers were desirous of possessing
objectives "which will resolve A. pellucida,^^ and regarded the
performance of this feat as the principal duty of an immersion
objective, it was natural that opticians should make every effort
to gratify their wishes. I have myself obtained excellent resolu-
tion of the transverse striae, at any rate, of A. fellucida, with
objectives which were practically useless for ordinary purposes,
such as the examination of Bacteria, etc.

Something better is required at the present time ; and until we
have, as is much to be desired, specimens of N, singalensis
mounted in realgar, I am inclined to think that the resolution of
the transverse striae of A. pellucida in this medium, with a full
solid axial cone of illumination, remains the best existing test of
the all-round capacities of an oil-immersion objective ; at any
rate, in the course of the e.xamjnation of a great nujnber of

114 M. A. AINSLIE ON NIT ZSCHIA SINGALENSIS I

different objectives by various makers, I have always found that
a good, clear exhibition of these striae under the conditions
indicated was a sufficient guarantee of the excellence of the
objective for all-round work.

I do not forget, of course, that Mr. Merlin records that he can
see the transverse striae, both of N. singalensis and of A. fellucida,
with axial illumination ; in the latter case when mounted in
balsam. This appears to me to prove that Mr. Merlin is blessed
with a keenness of eyesight far above the average ; I have looked
in vain for the slightest trace of the striae under these conditions,
and even in the case of A. fellucida the utmost I have been able
to do with axial illumination is to see the transverse striae faintly,
but certainly, in monobromide of naphthalin, with an apochromat
of N.A. 1*40, and with a fluorite objective of N.A. r34. I do
not, of course, claim that my own eyesight is in any way re-
markable ; indeed, in the matter of the detection of fine dark
lines on a bright background — which is here in question — I have
reason to believe that my sight is not particularly keen. I am
strongly of opinion, however, that this test is, for the great
majority of observers, much too severe, and probably too severe
also for the great majority of objectives.

Mr. Merlin's opinion as to the resolving power of objectives with
axial light as compared with oblique is certainly in accordance
with theory ; but even with the very best objectives obtainable
I have frequently found that I could, with oblique light, detect
striae which were wholly invisible with axial illumination.

There is one point in Mr. Merlin's paper which leaves me a little
puzzled : he refers to the difficulty he experienced in " stepping "
the stri^.e on N. singalensis, owing to their faintness, while on
the other hand he sees them with axial light. As far as my
experience goes, if diatom striae are visible at all with axial light
there is never any great difficulty in measuring them with oblique ;
I have measured the striae on A. fellucida in balsam, although in
this medium they are, to me, wholly invisible with axial light,
without any special difficulty due to their faintness.

I am showing the transverse striae on N. singalensis, resolved
with a Leitz 1/lOth oil-immersion of N.A. (measured) r33, not only
because they are of interest in themselves, in connection with
Mr. Merlin's valuable paper, but because it so happens that they
afford an excellent example of the occasional utility of a device

A NOTE ON MR. "IVIERLIN's PAPER. 115

which, though known for many years past, has never received
any very great attention from microscopists ; I refer to the
enhancement of the resolution by the introduction of an analysing
Nicol prism into the path of the rays ; in this case, for con-
venience, between the eyepiece and the objective, although its
effect is apparently the same wherever it is placed. Without this
device, I have been unable to see the striae, even with the greatest
possible obliquity in the incident light, with a flame-edge in use ^
I have seen them faintly, but certainly, with a gas-mantle and
strongly with a Nernst lamp ; but the effect of the introduction
of the analyser is, in the present case, most striking ; the resolu-
tion is perfectly plain with any illuminant in use, and there is not
the smallest difficulty (due to their faintness) in measuring them ;
the result, in the case of the specimen shown, being 115,000 to
the inch.

The light diffracted by diatom striae is found to be partially
polarised, to an extent depending (according to Mr. Conrady) on
the nature of the structure, and on the angle between the incident
and diffracted beams — that is to say, on the fineness of the stria-
tion ; and it is by no means with all such objects that the effect
is noticeable. The same authority points out that the fact of
the diffracted beam being polarised proves that the object cannot
be considered to behave as if it were self-luminous, as is claimed
by some of the opponents of the Abbe theory of microscopic
vision. Probably the effect of the polarisation in enhancing the
visibility of the striae, in cases where resolution occurs, is due
partly to the reduction in the intensity of the direct beam, the
diffracted beam being little, if at all, affected ; and partly, no
doubt, to some relation between the planes of vibration of the
light-waves in the two beams. The prism is placed with its
longer dimension parallel to the length of the valve, and at right
angles to the striae ; and although, as said above, the effect is
by no means invariable, I think this device is at all times worthy
of trial in the case of difficult resolutions.

In effecting difficult resolutions such as the case under con-
sideration, it seems necessary to have an illuminant of consider-
able intrinsic brilliancy ; i.e. very bright in proportion to its
size ; and the beam of light directed on the object should be as
narrow as possible, and at the extreme margin of the back lens
of the objective. A Nernst lamp gives an excellent result, and

116 M. A. AINSLIE ON NITZSCHIA SINGALENSIS^

even the little " flash-lamp " does admirably, on account of
its presenting a very small area of intense brilliancy ; but the
edge of a flame, although its total light may be greater, has
much less intrinsic brilliancy.

Though I understand that the resolution of N. singalensis has
been effected by means of the light from a flame-edge, both by
Mr. Merlin and Mr. Nelson, I should like to warn any microscopist
who sets out to see these striae with this form of illumination,
and without the addition of the analysing prism, that he is quite
likely to be disappointed.

Journ. quekelt Aticroacopicil Club, Ser. 2, Vol, XIII., No. 79, November 19IB»

117

AN HISTORICALACCOUNT OFTHE PSEUDOSCORPION-
FAUNA OF THE BRITISH ISLANDS.

By H. Wallis Kew.

{Read June 21th, 1916.)

Figs. 1-2.

The False-Scorpions are almost world-wide in distribution and
one may be sure that they have been known to man almost
everywhere in all ages. But records of such knowledge, pre-
served and accessible to us, are scarce until comparatively recent
times ; and indeed they do not become numerous until within
the life-time of men now living. There are two references to
these creatures in the works known to us as the Histories of
Animals of Aristotle which have undoubtedly come down from
what we regard as a remote age. The animals are there stated
to be found in books. Next, towards the renaissance of the
sciences, there is a mention of them by Scaliger, in 1557, who
gives for them the same habitat, and tells us that he found one
in Aristotle's book itself. After this, if we pass over a restate-
ment of Aristotle and Scaliger by Aldrovandi, in 1602, there is
nothing antedating the work of Hooke, with which the present
account commences. The Royal Society's order for the printing
of this work is dated November 23rd, 1664, and the book was
on sale before the then end of that year.* It contains the first
detailed description and the first figure of any animal of this
Order.

* Cf. Pepys ; January 20th, 166 f : "To my bookseller's, and there
took home Hook's book of microscopy, a mojst excellent piece, ,"
The date on the book itself is 1665,

118

H. WALLIS KEW : AN HISTORICAL ACCOUNT OF

1. Hooke, R. — Micrographia : or some Physiological Descrip-
tions of Minute Bodies made by Magnifying Glasses. London,
1665.

Hooke writes of a " Crab-like Insect." He saw it walking on a
book he was reading ; and, having a microscope by him, lost
no time in making a description and drawing of it (fig. 1). No
locality is mentioned, but from what we know of Hooke, it was

Fig. 1.

Reduced outline of the "Crab-like Insect " of Hooke (1), pi. xxxiii.
fig. 2. [ = Cheiridium museorum (Leach)].

certainly in England, and presumably in London, that the
observation was made. He relates, amongst other things, that
the creature had ten legs, eight of which, AAA A, were those on
which it walked ; and the other two, BB, which were the fore-
most, were formed in the manner of crabs' claws, the ends of them
being furnished with a pair of pincers, CC, which the animal did
open and shut at pleasure ; nor did it want other hands, having
another pair of claws, EE, very near placed to its mouth, and

THE PSEUDOSCORPION-FAUNA OF THE BRITISH ISLANDS, 119

seemed adjoining to it ; etc. (cf . fig. 2) = Cheiridium museorum
(Leach, 1817).*

The next detailed account and figure are those of " Die Scorpion-
Spinne " of Frisch's " Beschreibung von allerley Insecten in
Teutsch-Land," viii., published in Berlin, in 1730. Linnaeus'
" Systema Naturae " appeared in 1735, at Leyden, and con-
tained a citation of one of these animals : " Scorpio- Araneus "
(under Acarus).

Fig. 2.

Cheiridivm museorum (Leach). From Kew (38), pi. v. fig. 13.

2. Albin, E. — A Natural History of Spiders and other Curious
Insects. London, 1736.

Among the " Spiders " illustrated is one, which was found
amongst some books, and had " in the place of feelers two
long things like the claws of a lobster." = Chelifer sp.

* The present paper is not a bibliography of British Pseudoscor-
piones ; but, among the books and papers cited, are all those which,
following Hooke (1), make additions to this part of our fauna ; and,
interposed in smaller type, are references to further works which,
with many others, occupy important positions in the general literature
of the Order.

120 H. WALLIS KEW : AN HISTORICAL ACCOUNT OF

Linnaeus' " Sy sterna Xaturae " ed. x. appeared at Stockholm
in 1758-9; and contained two false- scorpions : Acarus can-
croides (Europe) and Acarus scorpioides (America). In ed. xii.,
Stockholm, 1766-8, these species were transferred to Phalangium
and the name of the second was changed to acaroides. Linnaeus
ignored Chelifer, which had been proposed in Paris, by Geoffroy,
in 1762 ; and it was not till 1785 that Fourcroy, also in Paris,
first used the familiar combination Chelifer cancroides.

3. Martin, B. — The Young Gentleman and Lady's Philosopliy,
iii. London, 1782.

Contains a long account in dialogue-form, and a grotesque
figure, of a " Lobster Insect," found by some labouring men in
a public-house, and borne away by an ingenious gentleman,
from whom the author borrowed it. = Chelifer sp.

4. Adams, G. — Essays on the Microscope. London, 1787.
From this book it appears that the public-house above referred

to was at Waltham Abbey ; and the gentleman w^ho bore away
the specimen was John Adams of Edmonton. From him it
passed to the author under notice, whose new figure of it re-
sembles in some respects Chelifer (Chernes) nodosus Schr., 1803.
The author tells us, moreover, of another specimen, in the pos-
session of Mr. Marsham, who found it fixed by its claws to the
thighs of a fly, which he caught on a flower in Essex. This is
the first record, in these Islands, of the clinging of false-scorpions
to flies' legs, the first known and only earlier one being in
Poda's " Insecta Musei Grcecensis " (Gratz, 1761).

5. Shaw, G. — The Naturalist's Miscellany, iii. London, 1791.
Contains a figure of " Phalangium cancroides J^ = Cheiridium

museorum (Leach, 1817).

6. Donovan, E. — The Natural History of British Insects, vi.
London, 1797.

Among the finely engraved and beautifully coloured plates of
this work is one of " Phalangium cancroides " which is stated to
be the largest insect of the genus found in England that re-
sembles a scorpion. = Chelifer cancroides (Linn.).

7. Kanmacher, F. — In Adams, G. — Essays on the Microscope,
ed. 2. London, 1798.

F. Kanmacher, who edited this edition of Adams (4), was
acquainted with several of these animals. He refers to one

THEP8EUD0SC0RPION-FAUNA OF THE BRITISH ISLANDS. 121

found on a bottle of wine in saw-dust in a cellar in Percy Street
[London], and to another found by a botanist among some
plants. And lie had lately seen another, in which the two fangs
[chelicerae] were very apparent, being so large as to exceed
in diameter the thickest part of the claws [palps]. This is
Chthonius sp. ; and is a very early reference to a false-scorpion
of that kind. The only earlier one is by Preyssler who estab-
lished Scorpio tetrachelatus [Chthonius tetrachelatus] in his " Ver-
zeichniss bohmischer Insekten " (Prague, 1790).

The celebrated " Memoire Apterologiq-ae " of Hermann (who
had died in 1794 at the age of 25) appeared in 1804 at Stras-
bourg, and contained the first methodical account of a series of
these animals. Six species (from the local fauna), studied with
ample magnification, were ably described and figured ; and
Chelifer (to which they were referred) was divided into two sec-
tions, which foreshadow the two main divisions of the Order —
Panctenodactyli and Hemictenodactyli — of modern authors.

8. Montagu, G. — Descriptions of several new or rare Animals,
principally marine, discovered on the South Coast of Devonshire.
Trans. Linnean Society, xi. pp. 1-26. London, 1813.

In this memoir, which Montagu had presented to the Society
in 1807, the false-scorpions are retained in Phalangium. Chelifer
had been " very properly instituted," but it had been thought
proper, in that place, to afhx to these insects the titles by which
they were generally known.* " Phalangium cancroides " is
employed as the name of a small species, = Cheiridium museo-
rum (Leach, 1817), which the author was accustomed to see in
one of his cases of preserved birds. His principal object, how-
ever, was to make known similar animals of another sort. Of
these he had two kinds or more ; but they are referred together,
with a mark of doubt, to " Phalangium acaroides.^^ The one
which concerns us here (of which a figure is given) was from

* Sir J. E. Smith, purchaser of Linnaeus' collections and insti-
tutor of the Society, was still President, and others supposed to be
bigoted to the system of Linnaeus were prominent in the Society's
concerns. A spirit of restraint was, no doubt, rife at this time ; but
it has been exaggerated. Montagu, in any case, would be a willing
co-operator, being himself mistrustful, as we learn elsewhere, of at-
tempts to improve on the Linnaean plan.

122 H. WALLIS KEW : AN HISTORICAL ACCOUNT OF

Cornwall, taken on rocks contiguous to the sea. = Obisium
maritimum Leach, 1817.

9. Leach, W. E. — Crustaceology. In Brewster's Edinburgh
Encyclopaedia, vii. pp. 383-437. Edinburgh [1814 ?]. *

This is the first of several contributions to our subject by
Leach — less than 25 years of age at this time — a man unfettered
by the traditions that had kept our naturalists in the wake of
those of France, and a warm advocate for generic divisions
founded on the consideration of every character. He was the
first in these Islands to adopt Chelifer ; and the first to dismember
it by the establishment of a second genus. The species listed
are not necessarily British ; among them, however, is Chelifer
tromhidioides Latr. — Ohisium trombidioides Leach's MSS. — which
had been found by Montagu in Devonshire, and by Leach in
Surrey. = Chihonius sp.

10. Leach, W. E. — A tabular View of the external Characters
of Four Classes of Animals which Linne arranged under Insecta.
Trans. Linnean Society, xi. pp. 306-400. London, 1815.

In this memoir Leach characterizes Chelifer and Ohisium as
separate genera ; and describes " Chelifer fasciatus " : Habitat
sub cortice arborum ; but without locality.

11. Leach, W. E. — Annulosa. In Encyclopaedia Britannica ;
Supplement, i. pp. 401-53. Edinburgh, 1816.

He states here that " Chelifer fasciatus " inhabits beneath the
bark of willow and other trees and occurs sometimes near Lon-
don ; cf. Leach (12) = Chelifer (Chernes) cimicoides (Fabr.).

12. Leach, W. E. — On the Characters of the Genera of the
Family Scorpionidea, with Descriptions of the British Species
of Chelifer and Obisium. Zoological Miscellany, iii. pp. 48-53.
London, 1817.

This memoir comprises — according to a statement probably
by Leach himself — a valuable monograph on the British species
of Chelifer and Ohisium, illustrated with very accurate figures
of the whole.* It is the first attempt to present in such a manner
this part of our fauna ; and it is noteworthy that, except in the
work of Hermann already mentioned, no similar task had been

* Leach ? — In Samouelle's Entomologist's Useful Compendium,
London, 1819.

THE PSEUDOSCORPION-FAUNA OF THE BRITISH ISLANDS. 123

undertaken for the false-scorpions of any region. The British
fauna is believed to comprise eight species. They are not all
regarded as new ; but oddly they all receive new names, the
older names of Hermann and Latreille and " Chelifer jasciatus "
of Leach himself being reduced to synonyms. The classification
and nomenclature are as follows :

Family Scorpionidea.
Genus Chelifer.

Sp. 1. Chelifer Hermanni.
Sp. 2. Chelifer Latreillii.
Sp. 3. Chelifer Olfersii.
Sp. 4. Chelifer Geoffroyi.
Sp. 5. Chelifer museorum.

Genus Ohisium.
Sp. 1. Ohisium orthodactylum.
Sp. 2. Ohisium museorum.
Sp. 3. Ohisium maritimum.

These eight species are dealt with in synoptical fashion and
figured. The diagnoses, however, are meagre ; and the figures,
on copper plates by K. P. Nodder, are poor. Taken together
they are insufficient, except perhaps in the case of " Chelifer
museorum,^'' for the determination of the species. Thus it
happens that most of the names have been, by one author or
another, misapplied ; and in some cases the species intended,
having been redescribed, became widely known under other
names. The specimens on which the work was based, however,
are preserved in the British Museum (cf. Cambridge, 27). They
have been obligingly shown to m€ on several occasions — acknow-
ledgments must be made in this connection to Mr. R. I. Pocock,
Dr. W. T. Caiman, and Mr. A. S. Hirst — and detailed micro-
scopical examinations have been made of them. There are
eighteen specimens, representing the eight names above men-
tioned. They bear numbers corresponding to entries in the old
catalogue-book of Leach's collections, and one individual in
each case is indicated as the type. The specimens are dry,
i.e. set out on card, and while some are in poor condition, the
collection as a whole is well preserved.

JouRN. Q. M. C, Series II.— No. 79. 10

124 H. WALLIS KEW : AN HISTORICAL ACCOUNT OF

1. Chelifer Hermanni. One specimen. Britain. = Chelifer
cancroides (Linn.).

2. Chelifer Latreillii. One specimen. Britain. = Chelifer
Latreillii Leach.

3. Chelifer Olfersii. One specimen. Britain. Palps lost and
surface-sculpture obscured, not determinable with certainty.
Cambridge (27) regards it as identical or probably identical with
the next species.

4. Chelifer Geoffroyi. {Chelifer fasciatus Leach, 10, 11). Two
specimens. Britain. Both badly corroded ; but a trace of the
sculpture is visible. = Chelifer {Chernes) cimicoides (Fabr.).

5. Chelifer museorum. Three specimens. Britain. = Cheiri-
dium museorum (Leach).

6. Obisium orthodactylum. Habitat sub lapidibus, in Dan-
monia et Cantia vulgatissime. Four specimens. Devon and
Kent. Three of them = Chthonius Rayi L. Koch, 1873. The
remaining one, which is that indicated as the type, is uncertain
from its bad condition, cf. Kew (38), p. 56 ; it is smaller than the
rest and I have followed Cambridge (27) in regarding it as the
smaller less deeply coloured species = Chthonius orthodactylus
(Leach).

7. Obisium museorum. Four specimens. Mountains of Scot-
land. = Obisium museorum Leach. The name was misapplied
by Simon (22) ; but Obisium museorum Leach of most authors
appears to be correctly named ; cf. Kew (38), p. 54.

8. Obisium maritimum. Habitat in Anglia occidentali inter
rupes ad littora maris. Two specimens. W. England. Pre-
sented by C. Prideaux, Esq. = Obisium maritimum Leach.

13. 0. — A lobster-like Insect attacking the Leg of a House-
Fly. Loudon's Magazine of Natural History, iv. p. 94.. Lon-
don, 1831.

This writer inquired the name of a creature having claws like
a lobster by one of which it clung to the leg of a House-fly ; he
thus initiated a correspondence in which Professor J. S. Henslow,
Mr. F. C. Lukis, and others took part ; and this is the first of
many similar discussions which have appeared in our magazines.
The name given is '' Chelifer cancroides ^ = Chelifer {Chernes)
nodosus Schr. ?

THE PSEUDOSCORPION-FAUNA OF THE BRITISH ISLANDS. 125

14. Templeton, R. — Catalogue of Irish Crustacea, Myriapoda,
and Arachnoida, selected from the Papers of the late John
Templeton. Loudon's Magazine of Natural History, ix. pp.
9-14. London, 1836.

Contains the first records of false-scorpions in Ireland. Two
species are given in the additions to the Catalogue which bear
the initials R. T. The first, without locality, is " Chelifer
muscBorum Leach " = Cheiridium museorum (Leach) ; and the
second, from Island Magee, Co. Antrim, is " Chelifer parasitica
Herm.," and is described as having " spatulate bristles" ; cf.
Kew (40) = Chelifer (Chernes) duhius (Camb., 1892) ?

15. Westwood, J. 0. — (1) Cheliferidse. In British Cyclo-
paedia of Natural History, ii. p. 10. (2) Entomologist's Text
Book, pp. 145-6. London, 1836-8.

" Highly interesting . . I have captured the largest species

which I have hitherto seen of the group, under the bark of trees

in Windsor forest, in the act of devouring the hard-cased beetle

{Bitoma crenata).^^ = Chelifer (Chernes) cyrneus (L. Koch, 1873) ?

C. L. Koch's " Die Arachniden," x., published at Niirnberg in
1843, is the first big work on these animals. It contains descrip-
tions of 26 species, mostly German, and there are eleven plates
of them, engraved on copper and coloured, and comprising alto-
gether 32 figures. The work is in many respects well done, both
descriptions and figures affording evidence of close study ; and the
author gave attention to certain details which subsequent writers
would have done well to notice. Chthonius is estabhshed here.

16. Curtis, J. — Observations on the Natural History and
Economy of various Insects affecting the Potato-crops. Journ.
Royal Agricultural Society, x. pp. 70-118. London, 1849.

In this paper, written from Hayes near Uxbridge, Curtis
describes and beautifully illustrates, without mention of locality,
a false-scorpion which had occurred in numbers among decaying
potatoes : Chelifer incequalis sp. no v. = Chelifer (Chemes)
nodosus Schr.

The often-quoted memoir of A. Menge " Ueber die Scheeren-
spinnen, Chernetidae," appeared at Danzig (N. Schr. Natf. Ges.,
v.) in 1855. The text leaves something to be desired in certain
respects, and the figures are crude, but the work is noteworthy
from the fact that it deals with species fossil in amber as well
as with recent species and with internal as well as external struc-
ture. Cheiridium is established here.

126 H. WALLIS KEW : AN HISTORICAL ACCOUNT OF

17. Lubbock, J. — Notes on the Generative Organs, and on the
Formation of the Egg in the Annulosa. Phil. Trans. Royal
Society, cli. pp. 595-627. London, 1861.

An important, much overlooked, work ; with a section on
" Scorpionidae " containing much of value concerning " Chelifer "
and " Ohisium,^^ the former [ = Chelifer (Chernes) sp.] found
*' under some planks which were lying on a hot-bed in our
kitchen-garden " [in Kent].

18. Mclntire, S. J. — (1) On Pseudo-Scorpiones. Journ.
Quekett Microscopical Club, i. pp. 8-14. (2) Pseudoscorpions.
Hardwicke's Science-Gossip, v. pp. 243-247. London, 1868-9.

These papers are particularly noteworthy. The author was
an enthusiastic member of this Club, deriving entertainment from
the use of the microscope, and with a passion for making out
the external features and habits of small creatures. He was
more intimately acquainted with false-scorpions than were any
of our previous authors. Seven or eight species came under this
writer's notice ; and some were kept in captivity for long
periods, his observations on them being of much interest. He
was concerned for the most part with two species, of which he
presented specimens to the Club, and they are still preserved in
our collections. The first, named " Chelifer Latreillei,^^ was found
" in considerable abundance in a brewery at Theale, Berks., by
F. Blatch, Esq., inhabiting the dark corners of the ale-store."
= Chelifer (Chemes) Panzeri C. L. Koch. The second, named
" Ohisium orthodactylum,^^ was found by Mclntire, no doubt in
the London district, under stones, brick-bats^ etc., and in cellars.
= Chthonius tetrachelatus (Preys.).

19. Koch, L. — Uebersichtliche Darstellung der europaischen
Chernetiden (Pseudoscorpione). Niirnberg, 1873.

L. Koch undertakes, in this small work of vi -f- 68 pp., with-
out illustrations, a revision of the false-scorpions of Europe. He
recognizes 48 species and 9 genera ; and the work is of impor-
tance, nothing similar having been attempted by any previous
writer. He had received English specimens from the Rev. 0. P.
Cambridge ; and this fact is indicated for five species : (1)
Chernes Hahnii{C. L. Koch) = Chelifer {Chernes) cimicoides (Fabr.);
(2) Chthonius Bayi sp. nov. ; (3) Chthonius tromhidioides (Latr.)

THE PSEUDOSCORPION-FAUNA OF THE BRITISH ISLANDS. 127

= Chihonius tetrachelatus (Preys.) ; (4) Roncus luhricus gen. et
sp. nov. : " Evd. 0. P. Cambridge fand diese Art in England,"
= Obisium (Roncus) lubricum (L. Koch) ; and (5) Roncus Cam-
hridgii gen. et. sp. nov. : " Bis jetzt nur in England (Rvd. 0. P.
Cambridge) gefunden," = Obisium (Ideoroncus) Cambridgii
(L. Koch).

20. Stecker, A. — Ueber die geographische Verbreitung der
europaiscben Chernetiden (Pseudoscorpione). Arcbiv fiir Natur-
geschichte, xli. pp. 157-182. Berlin, 1875.

A worthless memoir by the notorious inventor of " Gihocellum.^^
Lists eight species as British, including " Chelifer Schaefferi " =
Chelifer Latreillii Leach ? ; and " Chelifer ixoides " = Chelifer
cancroides (Linn.) ?

21. Dale, C. W.— History of Glanville's Wootton, p. 392.
London, 1878.

Records " Chernes Reussii (C. L. Koch) ; rare, and new to
Britain." = Chelifer {Chernes) nodosus Schr. ?

22. Simon, E. — Les Arachnides de France, vii. Paris, 1879.
This volume (pp. 1-76 and three plates) contains a general

account of the false-scorpions and a particular account of the
French species. Acknowledgments are made to L. Koch (19) :
" Cette excellente revision nous servira de guide, et nous aurons
meme peu de chose a y aj outer, ayant communique, il y a quelques
annees, toutes nos especes au Dr. L. Koch, pour en donner les
descriptions " ; but the work contains much that is new, and
none has become more widely known or has been more often
quoted. England appears, in the extra-French distribution,
under several species ; e.g. Chelifer Degeerii C. L. Koch. = Cheli-
fer Latreillii Leach.

23. Crowther, H. — Chelifer Degeerii C. L. Koch, a species
new to Britain. Zoologist (3) vi. p. 465. Hardwicke's Science-
Gossip, xviii. p. 277. London, 1882.

Found at North Berwick. = Chelifer Latreillii Leach.

At this period our animals were being studied in several coun-
tries. Simon's account of the French species (22) has been re-
ferred to above. Tomosvary's " Pseudoscorpiones Faunae
Hungaricse," an important work of 122 pages and 5 plates, ap-
peared at Budapest in 1882 ; Canestrini's " Chernetides Italici,"
another important work with many illustrations, at Padua in

128 H. WALLIS KEW : AN HISTORICAL ACCOUNT OF

1885 ; and about this time, also, appeared the first contributions
to this subject by H. J, Hansen — master of essential detail and
inimitable draftsman — whose works were published at Copen-
hagen in 1884-5. His " Arthrogastra Danica : en monographisk
Fremstilling af de i Danmark levende Meiere og Mosskorpioner,
med Bidrag til sidstnsevnte Underordens Systematik " (Nat.-
hist. Tids. (3), xiv. pp. 491-544). and the beautifully illustrated
account of the same animals in " Zoologia Danica " (4de. Hefte,
Spindeldyr), though long neglected by " the arachnologists of
the great nations," far surpass in value anything previously done
in this Order.

24. Cambridge, 0. P. — Pseudoscorpions new to Britain.
Naturalist, x. p. 103. London, 1885.

(1) From Dorsetshire and Yorkshire : Chernes nodosus (Sclir.)
= Chelifer [Chernes) nodosus Schr. (2) From Dorsetshire, among
moss in woods in the neighbourhood of Bloxworth : Chthonius
tenuis L. Koch. (3) From Kent, received in 1880 from Mr.
W. P. Haydon, of Dover, found by that gentleman in his oil-
mills : Chelifer subruher Sim. = Chelifer (Withius) subruber Sim.
The last was almost certainly imported ; but it appears to have
established itself in Britain (cf. Kew, 38).

25. Cambridge, 0. P. — A Contribution towards the knowledge
of the Arachnida of Epping Forest. Trans. Essex Field Club,
iv. pp. 41-5. Buckhurst Hill, 1886.

Records Ohisium simile L. Koch, presumably from near They-
don Bois ; but the species intended is Ohisium muscorum Leach.
The explanation of this and other records of Ohisium simile as
British is that Simon (22) confused Ohisiuin simile L. Koch and
Ohisium muscorum Leach under the former name and applied
Leach's name to another species (cf. Cambridge, 27 ; and Kew,
38).

In 1887, L. Balzan commenced at Asuncion (Paraguay) his
" Chernetidje nonnullge Svid-Americange "; and, in 1888, pub-
Ushed his " Osservazioni morfologiche e biologiche sui Pseudo-
Scorpioni del Bacino dei Fiumi Parana e Paraguay." In 1888,
also, appeared at Moscow (Bui. Soc. Nat., n. s., ii. pp. 416-61)
Croneberg's " Beitrag zur Kenntniss des Baues der Pseudo-
scorpione " : a work of much service in the study of this Order.

26. Cambridge, 0. P.— On New and Bare British Spiders.
Proc. Dorset Natural History etc. Field Club, x. pp. 107-133»
Porchester, 1889.

THE PSEUDOSCOEPION-FAUNA OF THE BRITISH ISLANDS. 129

Kecords Chelifer peculiaris L. Koch [found by the Rev. F. 0. P.
Cambridge in an old building at Hyde, near Bloxworth] ; but
the species intended is Chelifer (Withius) subruher Sim.

In 1890, L. Balzan reissued and completed his " Chernetidse
nonnullae Sud-Americanse " (of which three parts only had
appeared) in a valuable memoir with a long series of illustrations :
" Revisione dei Pseudoscorpioni del Bacino dei Fiumi Parana
e Paraguay " (Genova, Ann. Museo Civ. st. nat., xxix. pp. 401-
451) ; and in 1891-2 this work was followed by his " Voyage de
M. E. Simon au Venezuela : Chernetes " (Paris, Ann. Soc.
ent., Ix. pp. 497-552) in which the author proposed an elaborate
classification. The two main divisions, Panctenodactyh and
Hemictenodactyli, first appear here.

27. Cambridge, 0. P.— On the British Species of False-
Scorpions. Proc. Dorset Natural History etc. Field Club,
xiii. pp. 199-231. [Also separately with the title : Monograph
on the British Species of Chernetidea, or False-Scorpions.]
Dorchester, 1892.

This work, of 33 pages and 3 plates, contains the first attempt
since Leach's time to describe and illustrate our False-Scorpions.
It possesses the distinctive charm of the writings of its kindly
author — then and now Rector of Bloxworth and withal one of
the two or three really learned arachnologists of this time — and
it has been much used and much appreciated by our naturalists.
Moreover, it was a genuine contribution to knowledge, for the
author calls attention to the existence in the British Museum
of Leach's types, and gives the results of his examination of
them, together with descriptions of two new species. The work
is grounded on L. Koch (19) and Simon (22) ; and suffers some-
what from not taking into consideration the important studies
published during the years which had elapsed since the publica-
tion of those works. Further, it is well to remember that the
author's studies in these animals were along a by-path from
which he would, no doubt, be eager to return to the main course
of his spider-work ; and the same consideration applies to
Simon — to whom specimens were submitted — for though " un-
doubtedly at the head of all living arachnologists," he had, as
he told us a little later, " depuis longues annees neglige I'etude
4es Chernetes pour nous occuper exclusivement de celle des

130 H. WALLIS KEW : AN HISTORICAL ACCOUNT OF

vraies Araignees." * The British fauna, according to the
present work, comprised 20 species. All of them are described
in pleasant non-technical fashion ; and all are figured, often
with enlargements of detail, from drawings by the author him-
self. The classification and nomenclature are as follows :

Order Chernetidea,
Family : CheliferidcB.
Group I. — Four Eyes.
f Chihonius orthodaciylus , Leach.
t Chthonius Rayi, L. Koch,
t Chthonius tetrachelatus, Preyssler.
f Chthonius tenuis, L. Koch.
t Obisium muscorum, Leach.

Obisium sylvaticum, C. L. Koch,
t Obisium maritimum, Leach.

Group II. — Two Eyes.
t Roncus Cambridgii, L. Koch,
t Roncus lubricus, L. Koch.

Chelifer Hermannii, Leach,
t Chelifer cancroides, Linn.

Chelifer meridianus, L. Koch,
■f Chelifer subruber, Sim.
j" Chelifer Latreillii, Leach.

Group III. — No Eyes. I
t Chernes nodosus, Schr.

Chernes insuetus, sp. n.
t Chernes cimicoides, Fabr.

Chernes dubius, sp. n.

Chernes phaleratus, Sim.
f Chiridium muscorum, Leach. §

* Simon, E. — Note sur quelques Chernetes de Ligurie. Genova,
Ann. Museo Civ. st. nat. (2), xvi. (1890), pp. 372-6.

X Cheiridium is incorrectly supposed to be eyeless.

§ Opportunity must here be taken to acknowledge anew my in-
debtedness to the author. In years gone by — and it is a sad reminder
of the flight of time that my first specimens were despatched thirty
years ago — he examined many of these animals for me ; and more
recently has not hesitated to lend me specimens from his collections.
During 190G-10, for instance, I was permitted to see the types of

THE PSEUDOSCORPION-FAUNA OF THE BRITISH ISLANDS. 131

The 14 species marked f were already known as members
of om' fauna. With regard to the other names : (1) " Ohisium
sylvaticum,^^ a single specimen badly mounted = Ohisium {Ron-
cus) luhricum (L. Koch); (2) '' Chelifer Hermannii^^ ^ Chelifer
cancroides (Linn.) ; (3) " Chelifer meridianus,^^ a single speci-
men from Bloxworth, = Chelifer (Chernes) cimicoides (Fabr.) ? ;
(4) Chernes insuetus, from Mr. Haydon's oil-mills, foreign to our
fauna ; (5) Chernes duhius, found by the author at Glanville's
Wootton and by the Rev. F. 0. P. Cambridge at Sherborne, =
Chelifer (Chernes) dubius (Camb.) ; (6) " Chernes fhaleratus,'"
found by Mr. W. F. Blandford under bark of trees in the New
Forest in May 1890, = Chelifer (Chernes) scorpioides Herm.

H. J. Hansen published at Copenhagen, in 1893-4, a valuable
memoir : " Organs and Characters in different Orders of
Arachnids" (Kjobenhavn, Ent. Medd., iv. pp. 137-251) con-
taining for Pseudoscorpiones a classification which improves and
simplifies that of Balzan. Many errors which had become current
— and are unfortunately still current — are exposed ; and the
then recent papers of H. M. Bernard are criticized. That author's
often-quoted " Notes on the Chernetidae " (London, J. Linn. Soc.
Zool., xxiv. 1894, pp. 410-30) is full of misconceptions; audit
is hoped that the practice of repeating them in our books will
be discontinued. All Bernard's Arachnida-work (done hastily
in connection with the controversy about Limulus) requires critical
consideration. Barrois' magnificent " Memoire sur le developpe-
ment des Chelifer " {^Garypus'], with a long series of illustrations, was
published at Geneva (Rev. Suisse Zool., iii. pp. 461-98) in 1896.

28. Carpenter, G. H. — [" Chernes phaleratus (Sim.) " in Ire-
land]. Irish Naturalist, v. p. 215. Dublin, 1896.

Taken at Woodenbridge, Co. Wicklow, by Mr. J. N. Halbert.
= Chelifer {Chernes) dubius (Camb.) ? *

Ellingsen's " Norske Pseudoscorpioner " (Christiania Vid.-
Selsk. Forh. 1896, No. 5, pp. 1-21) appeared in 1897 [Supple-
ment, Id., 1903, No. 5, pp. 1-19] ; and Tullgren's " Bidrag till
kannedomen om Sveriges Pseudoscorpioner " (Ent. Tidskr.
Stockholm, xx, pp. 161-82) in 1899.

Chernes insuetus and Chernes dubius, and the specimens recorded as
" Chelifer meridianus " and " Chernes phaleratus." That recorded as
*' Ohisium sylvaticum " had passed out of the author's possession ; but
facilities for examining it were afforded me by a mutual friend in
1909. Cf. Kew (38), pp. 41, 54.

* Cf. Kew, H. W. — Notes on the Irish False- Scorpions in the
National Museiun of Ireland. Irish Nat,, xviii. (1909), pp. 249-50.

132 H. WALLIS KEW : AN HISTORICAL ACCOUNT OF

29. Godfrey, R. — Chernetidea or False Scorpions of West
Lothian. Annals of Scottish Natural History, x. pp. 214-17.
Edinburgh, 1901.

Records " Chernes fhaleratus (Sim.) " from Northbank,
Bo'ness. = Chelifer (Chernes) duhius (Camb.).

30. Donisthorpe, H. — Notes on the British Myrmecophilous
fauna (excluding Coleoptera). Entomologist's Record, xiv.
pp. 14, 67. London, 1902.

Records " Chthonius Hahnii C. L. Koch " in nest of Lasius
fuliginosus at Oxshott. = Chthonius Rayi L. Koch ?

31. Evans, W. — (1) Chelifer (Chernes) tullgreni Strand in
Scotland. (2) Chernes duhius Cambr. ( = C. tullgreni Strand)
in Scotland. Annals of Scottish Natural History, xii. pp. 120-1 ;
249-50. Edinburgh, 1903.

This animal, which Mr. Evans allowed me to see in 1903, is
that from Bo'ness already recorded as " (7. phaleratus " by God-
frey (29). = Chelifer (Chernes) duhius (Camb.).

An elaborately illustrated work on the anatomy etc, of Pseudo-
scorpiones [in Russian] by J. P. Schtschelkanowzeff was pub-
lished in Moscow in 1903 (Gelehrte Schriften d. Moskauer Uni-
versitat, Nat. Abt.) Cf. the author's " Beitrage zur Kenntnis
der Segmentierung und des Korperbaues der Pseudoscorpione "
(Zool. Anz., xxvi., 1903, pp. 318-34).

32. Cambridge, 0. P. — On New and Rare British Arachnida.
Proc. Dorset Natural History etc. Field Club, xxvi. pp. 40-74.
Dorchester, 1905.

Records Chernes cyrneus L. Koch new to Britain [a grand
addition to our fauna ; found in Sherwood Forest, in 1900 or
1901, by Dr. G. W. Chaster*]. = Chelifer (Chemes) cymeus
(L. Koch). Also " Chernes rufeolus (Sim.) " from " the Holborn
Granary" and ''Chernes phaleratus (Sim.)" from Dagenham,
Essex ; both = Chelifer (Chernes) Panzeri C. L. Koch.

33. Cambridge, 0. P.— /n Dyer, W. T. T.— The Wild Fauna
and Flora of the Royal Botanic Gardens, Kew. Kew Bulletin,
Add. ser., v. pp. 53-65. London, 1906.

* Kew, H. W. — Chernes cyrneus in Nottinghamshire : a recent
addition to the known False-Scorpions of Britain. Nottingham,
Trans. Nat. Soc, 1905-6, pp. 41-6,

THE PSEUDOSCORPION-FAUNA OF THE BRITISH ISLANDS. 133

Records " Chihonius tetradactylus " found inside a flower in
the rockery. = Chihonius tetrachelatus (Preys.) ?

A big work by C. J. With : " The Danish Expedition to Siam,
1899-1900. Chelonethi : An Account of the Indian False-
Scorpions together with studies on the Anatomy and Classifica-
tion of the Order " (Kjobenhavn, Vid. Selsk. Skr. 7, iii. pp. 1-214)
was published in 1906 ; and about this time also several other
works by the same avithor appeared either in Copenhagen or
London : all of the first order of importance. With's grasp of
the subject is remarkable ; and, among all his brilUant work, the
studies in Chelifer s. 1. are particularly valuable. He availed
himself fully of the good diagnostic characters already used by
H. J. Hansen (whose pupil he was), and discovered many new
characters of wide practical importance. Hansen and With are
the institutors of the modern study of Pseudoscorpiones, and a
knowledge of their work is essential to the equipment of those
who attempt to deal with these animals,

34. Cambridge, 0. P. — On New and Rare Britisli Arachnida.
Proc. Dorset Natural History etc. Field Club, xxviii. pp. 121-
48. Dorchester, 1907.

Records Chernes minutus Ell. from Elmer's End, Beckenliam.
= Chelifer {Chernes) scorfioides Herm.

35. EUingsen, E. — Notes on Pseudoscorpions, British and
Foreign. Journ. Quekett Microscopical Club (2), x. pp. 155-72.
London, 1907.

An elaborate report on a collection received from me in
1906. Records (1) Chelifer Chyzeri (Tom.), from Burnham
Beeches (Buckinghamshire), two specimens found under the bark
of a beech-stump, in 1905, = Chelifer (Chernes) Chyzeri (Tom.);
and (2) Chelifer Wideri C. L. Koch, found at West Wickham
(Kent), and in Sherwood Forest, under the bark of old oaks,
in 1905 and 1906. = Chehfer (Chernes) Wideri C. L. Koch.

36. Godfrey, R. — The False-Scorpions of Scotland. Annals
of Scottish Natural History, xvii. pp. 90-100, 155-61 ; xviii.
pp. 22-26, 153-63 ; xix. pp. 23-33. Edinburgh, 1908-10.

The Rev. R. Godfrey, who had already contributed several
smaller papers to the " Annals of Scottish Natural History,"
gives here the final account of his Scottish field-work.* No

* Godfrey left Scotland for South Africa during the printing of
these papers, and continued there his work on this Order ; cf. EUing-
seji's " Pseudoscorpions of South Africa based on the Collections of the

134 H. WALLIS KEW : AN HISTORICAL ACCOUNT OF

additions to the British fauna are made ; but our knowledge of
the range northwards, more especially along the west coast, of
several species is greatly extended ; and the pages are crowded
with observations on the natural historv of the animals.
Chthonius orthodactylus (Leach), not seen by the author, is
erroneously listed for Scotland.

37. Kew, H. W.— (1) A Holiday in South- Western Ireland:
notes on some False-Scorpions and other Animals observed in
the Counties of Kerry and Cork. (2) On the Irish species of
Obisium [s. s.] ; with special reference to one from GlengarifE
new to the Britannic fauna. Irish Naturalist, xix. pp. 64-73 ;
10&-112. Dublin, 1910.

Records, from Glengariff, Co. Cork, a large Ohisium (0. mus-
corum Sim., nee Leach), found in 1909, on a rocky wooded
hill-side, in moulting- and brood-nests under the outer bark
of Arbutus-trees [and in 1910, in the same place, under the
same conditions, and in rock-crevices and among dead leaves].
= Obisium Caxpenteri nom. nov. The animal is unknown in
Britain.

38. Kew, H. W. — A Synopsis of the False-Scorpions of Britain
and Ireland. Proc. Royal Irish Academy, xxix. B., pp. 38-64.
Dublin, 1911.

This memoir, of 27 pages and three plates, attempts to place
our knowledge of the British and Irish species on a firm basis.
The classification is derived from Balzan, Hansen, and With ;
but gives less weight to the presence or absence of the " galea " ;
etc. Brief comparative descriptions, and outline figures (in-
tended primarily to illustrate the general shape of the palps),
are given of 22 species. One of them, found in manure-heaps
etc. and on flies' legs in several localities, is an addition to the
fauna : Chelifer (Chemes) Godfrey! sp. nov.

An able and adequately illustrated account of the false- scorpions
known in Switzerland : " Catalogue des Invert^bres de la Suisse :
Pseudoscorpions," by Dr. R. de Lessert, was published by the
Museum d'Histoire naturelle de Geneve, in 1911.

39. Standen, R. — The False-Scorpions of Lancashire and some

South African Museum, Cape Town " (Ann, S. Afric. Mus., x,, 1912,
pp. 75-128).

THE PSEUDOSCORPION-FAUNA OF THE BRITISH ISLANDS. 135

adjoining counties, with a preliminary list of records. Lanca-
shire Naturalist, v. pp. 7-16. Darwen, 1913.

Kecords Chelifer Wideri C. L. Koch (so identified by me) from
two localities in Lancashire ; but it has since been found that
two species had been confused under that name (cf. Kew, 40) ;
the Lancashire specimens (of which one is figured) = Chelifer
(Chemes) Powelli Kew.

40. Kew, H. W. — A Synopsis of the False-Scorpions of
Britain and Ireland : Supplement. Proc. Royal Irish Academy,
xxxiii. B., pp. 71-85. Dublin, 1916.

Contains a redescription of Chelifer {Chemes) Wideri C. L.
Koch, and descriptions and outline figures of Chelifer [Chemes)
Powelli sp. nov., found in several localities in Britain, and a
Chthonius, discovered in 1915 by Mr. J. N. Halbert, on the sea-
shore, at Malahide, Co. Dublin. = Chthonius Halberti sp. nov.
The latter species has since been found in Britain.

This part of our fauna thus consists, as far as is known at
present, of the 24 species whose names appear in heavy type
in the foregoing pages. The list of them as given in the last-
quoted paper is repeated below.

List of the False-Scorpions of the British Islands.

PSEUDOSCOEPIONES.
I. Panctenodactyli.

CHELIFERIDAE.

Chelifer.

1, Chemes.
) nodosus Schr., 1803.
) Godfreyi Kew, 1911.
) Chyzeri (Tom., 1882).
) scorpioides Herm., 1804.
) dubius (Camb., 1892).
) Powelli Kew, 1916.
) Wideri C. L. Koch, 1843.
) Panzeri C. L. Koch, 1836.
) cyrneus (L. Koch, 1873).
) cimicoides (Fabr., 1793).

1.

Chelifer

(Chernes)

2.

Chelifer

(Ch ernes)

3.

Chelifer

(Chernes)

4.

Chelifer

(Chernes)

5.

Chelifer

(Chernes)

6.

Chelifer

(Chernes)

7.

Chelifer

(Chernes)

8.

Chelifer

(Chernes)

9.

CheUfer

(Chernes)

10.

Chelifer

(Chernes)

136 H. WALLIS KEW ON PSEUDOSCORPION-FAUNA.

2. Chelifer.

11. Chelifer (Chelifer) Latreillii Leach, 1817.

12. Chelifer (Chelifer) cancroides (Linn., 1758).

3. Withius.

13. Chelifer (Withius) subruber Sim., 1879.

Cheiridium.

1. Cheiridium museorum (Leach, 1817).

II. Hemictenodactyli.

OBISnDAE

Obisium.

1. Ideoroncus.

1. Obisium (Ideoroncus) Cambridgii (L. Koch, 1873).

2. Roncus.

2. Obisium (Roncus) lubricum (L. Koch, 1873).

3. Obisium.

3. Obisium (Obisium) museorum Leach, 1817.

4. Obisium (Obisium) Carpenteri Kew, 1910.

5. Obisium (Obisium) maritimum Leach, 1817.

CHTHONIIDAE.

Chthonius.

1. Chthonius Halberti Kew, 1916.

2. Chthonius Rayi L. Koch, 1873.

3. Chthonius orthodactylus (Leach, 1817).

4. Chthonius tenuis L. Koch, 1873.

5. Chthonius tetrachelatus (Preys., 1790).

Journ. Qiiekett Microscopical Club, Ser. 2, Vol. XIII., No. 79, November 1916.

137

ON SPORANGIAL CHARACTERS OF MYCETOZOA
AND FACTORS WHICH INFLUENCE THEM.

By a. E. Hilton.

{Read June 21th, 1916.)

Plate 9, Figs. 1-2 in text.

It is perhaps not sufficiently realised that in the small group
of the Mycetozoa we have not only a convenient microcosm of
elementary biological phenomena, but also a clue to the solu-
tion of some of the problems which those phenomena present.
Applying to the Mycetozoa words used by an eminent physi-
ologist in a similar connection, it may be said of these primitive
organisms that they show with singular clearness how '* quite
simple combinations of well-known forces lead to the perform-
ance of complicated and apparently purposeful results." * In
the light of this luminous principle, which is true of all living
things, we will consider some of the sporangial characters of
Mycetozoa.

It is, of course, important that the principle so expressed
should not be misunderstood. It is not stated that complicated
and apparently purposeful results are brought about by simple
forces ; but by well-known forces in simple combination. The
distinction is vital. It is the combinations which are simple,
not the forces. The forces, though well known, are mostly
inscrutable.

In appearance, the sporangia of Mycetozoa present a strange

♦ Principles of General Physiology. By Professor Bayliss of Uni-
versity College, London, 1916. The passage is given as quoted in
the Times Literary Supplement.

138 A. E. HILTON ON SPORANGIAL CHARACTERS OF MYCETOZOA

variety, especially after the liberation of the spores. For ex-
ample, the enclosing wall of Diderma floriforme splits into strips
which curl backward and simulate the petals of a flower. In
the lovely genus Arcyria, the capillitia are expanding nets of
wonderful delicacy and beauty. Alwisia bomharda, found in
Ceylon and Jamaica, is a remarkable species with a capillitium
of stiff fibres, quaintly resembling a shaving-brush. Neverthe-
less, despite all diversities of ultimate shapes, the initial forms
from which they spring are not difficult to account for. Owing
to the surface tension of the plasm of which it consists, a
sporangium, in the first instance, is necessarily of a rounded
contour. Indeed, some sporangia are almost perfect spheres ;
the surface tension, in such cases, finding almost complete
expression, as in the familiar instance of a mercury globule, or
a soap-bubble floating in air. At the surfaces of liquids or
semi-fluids, the tension tends to produce spherical forms because
it behaves like a stretched elastic membrane seeking to con-
tract ; and a sphere has the smallest surface for the volume it
contains.

It will help us to comprehend the aberrations from the spherical
form which occur in the majority of the Mycetozoa if we bear
in mind other facts concerning this well-known force, which
plays so important a part in biology. Surface tension, as now
understood, is a manifestation of cohesive force ; that is, of
the mutual attraction between molecules. Interiorly, this at-
traction is equal in all directions, and therefore balanced ; but
molecules at surfaces are subject to the unbalanced pull of
interior molecules, and this produces the tension which results
in sphericity. The force varies with circumstances. The
denser the body the greater the strain at the surface ; the more
fluid it is, the less the strain. Changing temperatures, causing
expansions or contractions, produce similar effects. Cold
increases surface tension ; heat lessens it ; so also do electrical
charges. It is therefore easy to understand that changing
conditions of warmth and humidity, or electricity in the atmo-

AND FACTORS WHICH INFLUENCE THEM. 139

sphere, may modify the spherical tendency of the highly plastic
plasm of rising sporangia.

Other modifying influences are the ingredients of the plasmodia
producing the sporangia. These may be roughly classified as
colloids, colloidal solutions, and suspensoids. The purer colloids
constitute the essential plasm, the living substance which divides
into spores after being relieved of its impedimenta. The colloids
in solution are albuminous refuse resulting from metabolism.
In the developing sporangia, they gelatinise into pellicles, or
coagulate into cartilaginous membranes either at interfaces or
exteriors, where they are trapped by the surface tension and so
concentrated. The suspensoids are particles of mineral or
vegetable substances, gathered up by the plasmodia in their
amoeboid wanderings and held in more or less stable suspension
until deposited owing to concentration, or to being trapped, like
the refuse colloids, at surfaces or interfaces. These particles
are mainly of a calcareous or cellulose nature, and furnish
materials of which the supporting structures, viz. stalks, colu-
mellae and capillitia, are chiefly composed.

To the interaction of these varying factors we must add
capillary effects due to watery condition of the plasm, also
effects of gravitation and of any lateral pressure there may be
by reason of congested surroundings. Desiccation likewise gives
rise to many and often strange distortions, owing to unequal dis-
tribution of impedimenta in the plasm, and consequent unequal
shrinkage in drying. Putting all these considerations together,
we see that sporangial forms are functions of many variables,
and that the diversified results exhibited after desiccation and
rupture of sporangia walls are scarcely to be wondered at. We
already perceive that " quite simple combinations of well-known
forces lead to the performance of complicated and apparently
purposeful results." The results are indeed manifold, but the
purposes we read into them are usually imaginary.

To establish the proposition that sporangia of Mycetozoa
when not actually spherical are to be regarded as globular forms

JouRN. Q. M. C, Series II.— No. 79. 11

140 A. E. HILTON ON SPORANGIAL CHARACTERS OF MYCETOZOA

modified and often distorted by factors which resist the surface
tension of the plasm, we will analyse the genera of the group,
in order to weigh the influence of these factors and trace their
distribution. This we can do by adopting the following con-
ventional figures as representing typical forms, with inter-
mediate connections, and grouping around these conventional
figures the natural forms approximating thereto.

B

Fig. 1.

It will be seen that A and C are depressed and elevated varia-
tions of B ; that D and E are stalked varieties of B and C ; and
that F is E much elongated.

A. Depressed Forms. — These mainly illustrate the effects of
gravitation and low surface tension. Depressed symmetrical
forms are either simple sporangia or cushion-like structures con-
sisting of confluent sporangia combined into what is called an
acthalium. Other and unsymmetrical forms spread on the
substratum with an irregular outline. They are known as
plasmodiocarps and are often much distorted. The majority of
the sixteen genera of the Calcarineae present these flattened or
irregular forms, owing to the quantity of lime (calcium car-
bonate) which their plasm contains. Of the thirty-two other

AND FACTORS WHICH INFLUENCE THEM. 141

genera of the Mycetozoa, which are without lime, less than half
show such forms. These are due to the fluidity of their plasm,
or to the aethalial confluences resulting therefrom. The weaker
the surface tension the less support it affords to the mass, and
the greater the depression by gravitation. Capillary effects and
distortion by shrinkage in drying are likewise pronounced.

B. Globular Forms. — In these the spherical tendency of the
surface tension finds its clearest expression. If for a moment
we use the language of art rather than of science, we may say
that " the complete and consummate form " which is hinted at
by the Mycetozoa is a perfect sphere. These globular shapes
are exhibited by less than half the genera of the Calcarineae, the
lime often being an impediment. Of the remaining genera
about half exhibit them.

C. Cylindrical or Vertical Forms. — In this diagram the sphere
is distorted by being drawn upwards, the vertical axis gaining
length at the expense of the horizontal circumference. The
natural forms which group themselves round this conventional
figure are significantly few and diverse. Only two genera of
the Calcarineae, and six of the remaining genera, exhibit them ;
altogether but one-sixth of the forty-eight genera of Mycetozoa.
In most cases the more or less cylindrical sporangia are somewhat
curved ; in other instances they are clavate (club-shaped) or
pyriform (pear-shaped), much larger at the apex than at the
base. These latter suggest a tendency to form a stalk. In the
main these upstanding forms result from lateral compression,
the sporangia being so crowded on the substratum that in order
to relieve the side pressure the plasm is forced to extend upward,
that being the only direction in which relief is possible. In those
genera in which the sporangia stand singly, the upward exten-
sion is due to the surface strains being modified by unequal
distribution of interior deposits, or varying concentrations of
the plasm. The definite relation between interior densities and
surface tensions obviously affects the shape of a sporangium
when from any cause such densities vary throughout the mass.

142 A. E. HILTON ON SPORANGIAL CHARACTERS OF MYCETOZOA

D. Globular Forms with Stalks. — Here again, as in the sessile
forms B, the plasm follows to a great extent its natural tendency
to round off into spheres ; but not until it has deposited a stalk
on which it raises itself from the substratum by clinging to the
upper end and drawing up from the base. More than half of
the genera of the Calcarineae produce these forms, the lime left
behind in the stalks leaving the plasm at the summit more free
to assume a globular shape. Of the genera without lime about
half exhibit them, the stalks of these being chiefly of a cellulose
nature.

E. Cylindrical or Vertical Forms, Stalked. — As in the case of
the sessile forms C, the genera presenting these are compara-
tively few, comprising four genera of the Calcarineae and five
of the other genera. In one or two instances the sporangia are
clustered and therefore partially moulded by lateral compres-
sion, but more frequently the vertical lengthening is a result of
the stalk continuing upwards as a columella with branching
capillitia nearly or quite to the summit of the sporangium. In
other instances where there is no columella the sporangium is
moulded on a frame of closely packed capillitia which afterwards
expands into a light mass of fibrous network.

The feature which these stalked and lengthened forms pre-
eminently illustrate is the effect of inner structure upon outward
form. In rising sporangia the arrangement of the material
which forms the capillitium is primarily controlled by the plasm
which deposits it ; but as the process proceeds the secreted sub-
stances harden into a scaffolding of increasing firmness, and
control partially passes over from the plasm to the rigid struc-
tures, which largely determine the final shape of the sporangium.
Surface tension so far operates as to draw the plasm upwards
clear of the stalk, but the capillitium then arrests the climbing
movement, and the compromise between these two factors,
coupled with shrinkage effects of desiccation, lead to the charac-
teristic more or less cylindrical shapes.

F. Cylindrical Forms, Stalked and Elongated. — This diagram

AND FACTORS WHICH INFLUENCE THEM. 143

is similar to E but much elongated, and conventionally repre-
sents a few striking cases in which cylindrical forms are lengthened
to an extreme degree. The genera which produce them are
chiefly Stemonitis and Comatricha, which may almost be re-
garded as a single genus, the distinction between them being
ratherartificial, though convenient for classification. In Stemonitis
the sporangia are sometimes four-fifths of an inch in length
and fairly upright, but in Comatricha (C longa, found in Asia,
Africa and America) the sporangia are sometimes two inches
long, and are flexuose and drooping, owing to the weakness of
the columella. In both instances the fasciculate sporangia
mutually support each other during formation, but after drying
they are apt to separate and bend over. The only example in
the Calcarineae of a form at all similar is Erionema, a genus of
a single species. When sessile, the sporangia, which are very
small, frequently appear as branched plasmodiocarps ; but it
also presents stalked and lengthened forms, prone or pendant,
owing to weight of lime in the sporangium walls, and the weak-
ness of the capillitium which is merely an expanding network
of slender threads, unsupported by a columella. In all three
cases the form-giving effect of interior, deposits is accentuated in
the exceptional length of the sporangia ; but although sphericity
is lost, surface tension is still evident in their cylindrical round-
ness. Moreover, we must remember that whatever restraints
interior deposits may impose on the plasm while a sporangium
is forming, surface tension at last finds full and free expression
in the sphericity of the spores produced. In multitudinous
spore-cases of globular shape the whole of the clarified plasm
rests awhile till surroundings favour the renewal of its activities.
From this analysis we find that in the production of sporangial
forms, surface tension, free or restrained, is the dominant factor ;
that gravitation is strongly influential ; that lateral compression
helps to mould some of the vertical forms ; that capillary effects
are traceable ; and that desiccation affects more or less, and
sometimes much distorts, the maturing sporangia. It is un-

144 A. E. HILTON ON SPORANGIAL CHARACTERS OF MYCETOZOA

doubtedly true that simple combinations of these " well-known
forces " lead to " complicated and apparently purposeful results,"
but the supposed " purpose " always ends in simple spore-pro-
duction, however intricate the processes may seem to be.

In the case of sporangia which are not sessile, the formation
of a stalk becomes more intelligible when we realise the essential
fact that stalk and sporangium develop concurrently as the
dual result of one and the same process. A good illustration of
this is furnished by the well-known species Comatricha nigra,
the successive phases of which are indicated by the following
figures :

cy Gl

B

A. Cushion of watery plasm on surface of dead wood, from

interior of which it has just emerged.

B. Plasm more erect, with base of stalk visible at centre.

C. Stalk lengthening upward. Plasm still adhering to base.

D. Further extension of stalk. Plasm detached from base, and

being drawn upward by rounding action of surface tension.

E. Stalk at full length. Plasm rounded by surface tension.

Interior secretions from plasm forming capillitium branch-
ing from summit of stalk. Capillitium partly visible.
Sporangium becoming opaque.

F. Final shape of sporangium. Spherical form modified by

capillitium and effects of desiccation.
This is a fair example of the general process of stalk-formation
throughout the group, due allowance being made for specific
differences in the plasm, especially of those species containing

AND FACTORS WHICH INFLUENCE THEM. 145

lime. Both sessile and stalked sporangia are frequently produced
by one plasmodium, and in such cases the presence or absence
of a stalk evidently depends upon contingent rather than specific
conditions.

The morphological effect of the presence of lime in sporangia
is well indicated by the large proportion of species to genera in
the Calcarineae as compared with other genera and species. The
figures are :

Genera percent. Species percent.

Calcarineae 16 0'33 129 0*52

Other Endosporeae . . . 32 0-67 116 0*48

48 1-00 245 1-00

These figures show that more than half of the species belong
to the Calcarineae, although the genera containing them are
but one-third of the genera included in the group. Under the
varied conditions of environment in different parts of the world,
lime in sporangia tends to multiply the number of characters
regarded as specific. This is strikingly illustrated by the genus
Physarum, which is divided into fifty-seven species, whereas the
average number of species in a genus of Mycetozoa is five. From
the fact that only a portion of the group contains lime, and that
sporangia without lime are occasionally found even in the Cal-
carineae, we may conclude that calcium carbonate, although
utilised by the plasm in which it occurs, is not an indispensable
element of it. When afterwards eliminated it is deposited in
a variety of ways, sometimes as a central ball within the
sporangium, frequently in the form of a columella, generally in
the stalks or embedded in the sporangium walls, or forming an
outer crust of stellate crystals. There are two singular cases
which also present a contrast. In Physarella there are cal-
careous spines attached to the sporangium walls and pointing
inwards until the walls are ruptured. In Physarina the walls
are covered with calcareous protuberances pointing outwards,
resembling the spines of an echinus. It is appropriately named
P. echinocephala.

In all sporangia of Mycetozoa, probably without exception,

146 A. E. HILTON ON SPORANGIAL CHARACTERS OF MYCETOZOA

there is material of a cellulose nature ; and this must be re-
garded as an inevitable result of the metabolism of the plasm.
It is secreted in more perfect forms than the lime, and their
characteristics suggest that chemical as well as physical processes
are involved in their production. The minute spore-cases, of
different patterns, the slender threads of capillitia, often with
excessively jfine markings upon them, and sundry delicate mem-
branes, are all of this material ; and in combination with
albuminous refuse, also the result of metabolism, it enters into
the composition of cartilaginous stalks and sporangium walls.
Speaking generally, the lime deposits are coarser and conditional ;
the cellulose deposits inevitable and more specific. The cellulose
substance is in closer relation to the plasm ; but in the pro-
cesses of spore formation it is equally eliminated.

The visible changes of colour, significant of interior rearrange-
ments, which occur while sporangia are forming are remarkable.
In the case of the familiar Comatricha nigra, for example, the
plasm, at the outset, is watery or milky white ; but as formation
proceeds, the colour of the sporangium successively changes to
pink, light red, coral red, black and purple-brown. A specimen
of Dictydiaethalium plumbeum, watched by me during develop-
ment, appeared on a piece of branch first as a chalk-white layer,
then contracted into a cushion of brilliant rose-pink, and finally
matured into an aethalium of a drab-clay colour. Plasmodia
of Lamproderma are watery-white or colourless, but developing
sporangia, after turning brown or reddish-brown and then black,
finally become iridescent, bronze-like, or shining like burnished
brass. We find, indeed, that if we take into account the whole
range of sporangial forms of Mycetozoa, all the prismatic colours
are represented more or less closely, but in unequal degree. It
is noticeable that green, blue and violet, though not absent, are
in very small proportion. This suggests a tendency to absorb
the light rays of the upper half of the spectrum. Conversely, the
colours of the lower half of the spectrum, yellow, orange and
red, are more in evidence ; yellow tints preponderating, with

AND FACTORS WHICH INFLUENCE THEM. 147

shades of red in fair proportion. The yellows are probably attri-
butable to the albuminous contents of the plasm ; the reds are
more likely due to the cellulose substances. Both albumin and
cellulose are carbon compounds with hexonic bases ; and this
" ring-structure," as it is called in chemical symbolism, is re-
garded as particularly favourable to colour development.

Purely chemical features, however, are usually obscured by
changing physical conditions. In the early stages of sporangial
formation, the plasm is still watery and reflective ; and this, in
conjunction with the presence of lime, albumin and cellulose,
or any combination of them, gives rise to light and bright tints
of many shades of white, yellow or red. As condensation pro-
ceeds, and interior structures are increasingly deposited, there is
less reflection of white light, the colour effects of the secretions
within the semi-transparent plasm become more pronounced,
and the tones tend to deepen or darken. By the time the
sporangium walls have formed, but while they are still moist,
there is in numerous cases an almost complete absorption of
light, producing a nearly black appearance. On drying off,
colour reappears in most instances, but with a difference. Their
prevailing hues are now shades of black, purple or brown ; the
browns, in beautiful variety, being in the ascendant.

In the Calcarineae the general course of the coloration pro-
cesses is affected by the lime embedded in the walls, or masked
by lime-crystals encrusting the sporangia. When these fall
away, darker surfaces are seen. The iridescent or metallic
appearances presented by certain species, both of Calcarineae
and other genera, are due to prismatic or interference effects,
produced by mineral particles or surface membranes, hyaline
or translucent.

Here, for the present, our analysis ends. When we are asked
what is the use of studying Mycetozoa, our answer is that, so
far as we are able, it is our business, as microscopists and nature-
students, " to make each small thing unfold its secret, and in
so doing, perhaps, to unfold other and wider secrets."

148 a. e. hilton on sporangial characters of mycetozoa.

Bibliography.

DE Bary, a. : Comparative Morphology and Biology of the
Fungi, Mycetozoa and Bacteria, Eng. trans., Oxford. 1887.

Lister, A. : A Monograph of the Mycetozoa ; a Descriptive
Catalogue of the Species in the Herbarium of the British
Museum, 2nd Ed., revised by Gulielma Lister. London.
1911.

Minchin, E. a. : An Introduction to the Study of the Protozoa.
London. 1912.

Willows, E. S., and Hatschek, E. : Surface Tension and Sur-
face Energy and their Influence on Chemical Phenomena.
London. 1915.

Bradford, S. C. : Colour and Chemical Structure. Article
published in Science Progress for Jan. 1916.

Description of Plate 9.

A. *Fuligo septica^ \ nat. ■\Dictijdiaethalium plumbeuyn,

size. nat. size

B. *Badhamia foliicola, x 6. ■\Margarita metalUca, x 20.

C. *Diachaea cylindrica, x 8. IfHemitrichia vesparium, x 8.

D. *Diachaea splendens, X 11. 1[Lamprodermaarcyr{onema,x 12.

E. *Diachaea lencopoda, x 15. ^Lamproderma columbiniim, x 5.

F. -fStemonitis fusca, nat. size.

* Containing lime. f Without lime.

Joum. Quekett Microscopical Clitb, Ser. '2, fol. XIII., Xo. 79, yoveiiiber 1916.

JouRN, Q. M. C.

Ser. 2, Vol. XIII, PI. 9.

A

A. E. Hilton del.

Adlard 4" J^est Newman.

Typical Sporangia of Mycetozoa.

149

ON THE BDELLOID ROTIFERA OF SOUTH AFRICA.

PART II.
By W. Milne, M.A., B.Sc, F.R.S.E.

{Read October 24:th, 1916.)

Plates 10-14.

In a footnote * to Part I of this paper I stated that I had in-
advertently made use of a generic name (Monoceros) in the
description of a new Bdelloid genus, which was already pre-
occupied and therefore inadmissible.

I propose here to change the generic name Monoceros, with
its derivatives Monocerotidae and Monoceros falcatus, into
Henoceros, Henocerotidae and Henoceros falcatus.

In Part I, pp. 77-82, I gave descriptions of three new species
of the genus Macro trachela, and shall now complete my list :

Genus MACROTRACHELA.

Macrotrachela verecunda sp. no v.
PI. 10, figs. 1-lc.

Specific Characters. — Of small size. Trunk dark brown and
deeply ridged. Rostrum long and very narrow, with double
lamella. Antenna long and stout, equal to fully three-fourths of
neck width, and bearing long setae. Teeth two. Foot short
with narrow ankle and three stumpy toes. Spurs not very long,
of a distinctive shape. Corona equal to collar in width. Sulcus
very narrow. A slow creeper. Size, 1/1 20th inch.

This is a very small animal with a dark brown trunk and very

hyaline neck and foot. The trunk has uneven coarse ridges,

giving it an appearance resembling the surface of the rough bark

of a tree. The skin must be viscous, as fragments of the debris

* Journ. Q.M.C., ser. 2, vol. xiii. p. 49.

150 W. MILNE ON THE

were seen adhering to the trunk. It is rather a sluggish creeper,
with a very deliberate slow pull-up of the foot. It seems to avoid
the open, and to prefer to withdraw under shelter ; and on
account of this habit, and its small size, it is very difficult to
examine.

The rostrum is very narrow, but the double lamella is quite
prominent. The antenna is long and stout, and has very charac-
teristic brushes of setae. These brushes are extremely long, and
always show the same graceful curve, and so .clear are they that
they are easily distinguished with a 1 inch objective. There are
prominences on each side of the antenna, like those seen on the
spined varieties of Macrotrachela. The dental bulb is heart-
shaped and there are two teeth.

The foot is short and the ankle very narrow. The spurs are
rather short, and have their outer borders convex and the inner
curves concave, producing a converging effect.

The shape and character of the antenna brushes and the spurs
are very constant and distinctive.

The corona is equal in width to the prominent collar, and the
sulcus is extremely narrow on the ventral side, the wheels almost
approaching each other. The upper lip is glaucous, and re-
fraction from parts below causes optical difficulties. What
appears to be the upper lip consists of a triangle over an oblong.
It is not easy to make sure whether the oblong belongs to the
upper lip or is part of the rest of the corona. The apparent
upper lip shows fully higher than the corona, broad across.
A\^ien the lip is looked straight down upon — that is, when the
animal is feeding in a perpendicular position — the upper edge is
convex dorsally and shows three parts (PI. 10, fig. Ic). The
middle part seems to be the cross section of the triangular part
lying on the oblong. The triangular part was not always
well seen. The oblong may possibly be a high ridge from wheel
to wheel crossing the sulcus, and shown up by the triangular part.
The base of the upper lip is thick and raised like a frill.

Habitat. — Not very often seen, but possibly common enough,
as I saw samples from three different places. They are easily
overlooked on account of their small size and their habit of
resting under the rubbish.

Found in ground or rock moss Grahamstown, also Euphorbia
Kloof and Draaifontein farm, Uitenhage district.

BDELLOID ROTIFERA OF SOUTH AFRICA. 151

Macrotrachela smithi sp. nov.
PL 10, figs. 2--2a.

Specific Characters. — Of large size and elongated. Corona
wider than the collar, and sulcus equal to four-fifths of the disc.
Upper lip a bold semicircular curve with a narrow abrupt notch
in froi t. Antenna short, barely equal to one-third of neck width.
Teeth two, well apart. Heavy rump and short foot. Spurs
divergent with fairly wide convex interspace, distinctive. Toes
three, stout. Size, l/65th inch.

This is a large handsome animal. When fully extended, the
width from the rostrum to the rump very gradually and scarcely
perceptibly increases. The pre-anal segment is heavy, and is
distinctly marked o£E from the trunk. Older specimens seem to
creep rather laboriously, but the younger ones are active. In
some there were large oil globules in the stomach investment
extraordinarily liL'e pellets, but it was noticed that only granular
matter was voided. The trunk is freely ridged.

The rostrum is stout, and has a large prominent double lamella,
with several long setae, some of which are motile. When feed-
ing, the rostrum often lies over the upper lip, and whether so or
tossed farther back its cilia were always seen to be in rapid
motion. The short antenna has three little knobs at the end,
and has on each side of it a swelling or protuberance. Small,
roundish jaws bear two teeth, far apart. The contractile vesicle
is large and of slow period. There are probably four segments
in the foot, which is short, and ends in three stout toes. The
second segment is extremely short, and may possibly be the spur
segment. Spurs are of moderate length, about equal to three-
fourths of the ankle width. They are widely divergent, broad
at the base and narrowing suddenly on the inside half-way down,
becoming very attenuated and ending in very sharp points.
There is a convex interspace. An elegant appearance is given
to the spurs by the graceful lines bounding them.

There is a seta with a bulbous base on each wheel of the
handsome corona. The sulcus is wide and the collar prominent.
Corona, collar and neck are to each other as 14, 10 and 9. The
upper lip is semicircular with an abrupt notch in front, which
just breaks the bold outline.

152 W. MILNE ON THE

The egg is more oblong than oval, narrowing very little at
the two ends.

This Macrotrachela has a general resemblance to a species of
Philodina which I have seen in South Africa. The latter is
similar to, if not the same as, one which Mr. Bryce has named
P. patricia, but has not yet published a description of ; he kindly
sent me some specimens. The curve of the upper lip is not so
bold, and the spurs though similar are not the same in detail.

Habitat, — Ground moss, Kamaehs farm, Uitenhage. The
species was obtained from the one place only, but was seen on
different occasions. It has not been observed again recently.

Macrotrachela timida sp. nov.
PL 10, figs. 3-3a.

Specific Characters. — Of large size, hyaline except the stomach
investment, which is of a pale decided pink. In general ap-
pearance, more especially in the rump and spurs, it is similar
to M . plicata (Bvyee) . Deeply plicate. Rostrum long and stout.
Antenna equal to one-third neck width. Teeth two. Spurs
divergent and decurved slightly, and equal to ankle width.
Corona wider than prominent collar, with a seta on each wheel.
Sulcus equal to two-thirds disc. Upper lip rises, almost square
across in front. A fleshy tooth in sulcus. Size, up to l/60th inch.

This is an exceptionally handsome animal when feeding. It
has, like all having the type of rump of M. plicata, a most irritating,
jerky manner of creeping. But this one seems wanting in
pluck, and is easily stopped in travelling, by obstacles, and
contracts even when meeting with slight obstruction. It does
not feed readily in the open, and after a time all will have retired
into hiding. Some could be discerned feeding amongst the
debris, but of course details could not be made out. At last I
thought of washing the rubbish off them. Waiting a day or so
till they had quieted down and felt at home, I ran a drop of water
under the cover-glass ; this broke up the rubbish and carried it
down towards the other end, and generally left M. timida
uncovered, and feeding away gaily. They generally kept on
feeding for some time very quietly and steadily, before seeking
shelter again. In a few hours all would be once more hidden
from view.

BDELLOID ROTIFERA OF SOUTH AFRICA. ] 53

The rostrum is long and stout, and seems to have the quadruple
lamella, but of this I could not make quite sure. There is a large
brain mass. The dental bulb is winged and has two strong teeth.

The trunk is almost equal to the rest of the animal in length
and shows five clear divisions of about equal length. It has the
toughness and elasticity of skin of M. musculosa, which enables
it to keep a perfectly regular shape, whether extended or con-
tracted.

The lumbar region has what might be called the " crinoline "
type. The anal segment stands out with a sort of thin almost
rigid flange at bottom — one could almost imagine a wire support
inside — so that whatever tightening or alteration takes place in
front, the posterior maintains its wide and peculiar shape. The
pre-anal segment also keeps its shape as if it were stiffened.
Whether the animal is stretched or relaxed, the shape of the
rump is practically constant. The lumbar region, seen sideways,
looks the deepest part of the body, largely due to the lumbar
plicae standing up so high. These lumbar plicae, which look like
two firm smooth membranes with their lower edges deep down,
rise up above the surrounding surface ; the upper edges have a
convex curve longitudinally. There is an abrupt dip from the
anal segment to the foot. The intestine is a large oval, but the
contractile vesicle is rather small.

The foot has four segments, and has no boss. Of the segments,
the first is the longest and ends in a rigid rim, the second has also
a rim but smaller. The spurs are divergent and decurved, and
as long as the width of the ankle. There is a very short inter-
space, and a slight shoulder is usually apparent just below. The
spurs are often clipped together.

The corona is bold, and is to the collar as 14 to almost 11. The
upper lip is clear cut and of a glassy colour. It rather more
than covers the sulcus, and has a clean-cut almost straight
front margin. About half-way back there is a line or ridge
across the lip, and between this and the front margin on the
lateral borders are two curves, probably defining skin folds.
There is a short fleshy tooth on the sulcus bridge w^hich shows
in certain positions only, when the head is well up.

The egg is a broad oval, almost round, and has blunted narrow
prominences all over the surface, almost touching each other,

M, timida can be kept in a slide for a considerable time.

154 W. MILNE ON THE

Habitat. — Ground moss, Springfield and Euphorbia Kloof,
Uitenhage, also Sornerset East. They were abundant in one
sample of moss, but only a few were noticed in the other samples
where they occurred.

Macro trachela timida var. inquies.
PL 10, fig. 4.

Specific Characters. — Long and rather narrow, swelling slightly
towards the middle of the trunk. Rump has the crinoline arrange-
ment permanent in all positions. Foot is fairly long and very
narrow, of at least four segments and with a boss on the first.
Spurs fully longer than ankle, divergent, w4th short interspace
and a slight shoulder below. Rostrum long and narrow. An-
tenna short, about one-fourth neck width. Teeth two, not very
large. Corona scarcely wider than the non-prominent collar,
and with a seta in each w^heel. Upper lip rises high, practically
square in front. Size, l/75th inch.

This is a very fast, restless, jerky creeper. The corona collar
and neck are nearly equal in w4dth. The upper lip is thick and
fleshy, and rises as high as the highest part of the wheels. It
springs laterally from well above the widest part of the collar,
and lies almost against the secondary wreath. The front margin
is fairly broad and is practically straight across when the animal
is feeding in a horizontal position. Along the middle of the
upper lip longitudinally, the flesh is thicker and bulges up.
AMien the head is well below the horizontal, this elevation hides
the straight front margin, and gives the appearance of a rounded
margin. The pedicels are deep, and the rostrum lies far back
when the corona is unfurled.

The trunk is closely ridged.

Habitat. — Ground moss, Kamaehs farm, and tree moss, Bulk
River, Uitenhage.

Fairly common.

There are one or two other varieties, which differ chiefly in the
nature of the foot.

These wickedly restless creepers form quite a little group —
M. plicata, M. plicatula, M. ehrenhergii, M. timida and its varieties.
It is quite easy to go astray among them, as one gets as a rule
very little opportunity of examining all the details at a time,

BDELLOID ROTIFERA OF SOUTH AFRICA. 155

they being usually shy feeders, and one may chance on another
species next time when examining the field, as all are somewhat
alike while creeping. Besides their similarity in habits, all have
similar spurs, and the crinoline type of rump, either permanently
or to a certain degree when relaxed and sitting back on the foot.
M. plicata is the only one which has not got the unbroken front
margin of the upper lip, and which is not very shy in feeding.
The animal I take to be M. ehrenhergii has more segments than
eleven, but otherwise answers fairly well to the description (1).
The peculiar extensions of the rostral sheath or auricles described
by Janson are evidently part of the lamella, which appears
quadruple. The two inner folds were evidently taken by Janson
to be the whole lamella. M. flicatula as I found it had the pro-
jecting broad annulus on the posterior of the first segment of the
foot, and not on the second as given by Murray (6).

Macrotrachela faveolata.

PI. 10, figs. 5-5d.

Specific Characters. — Of large size. Stomach investment deep
yellow. Antenna stout. Dental bulb roundish with thick
comb-like edges, bearing eight large teeth. Stout lumbar region
and foot. Spurs and upper lip somewhat like those of M. russeola.
Corona just wider than the collar. Sulcus slightly over half the
width of disc. The main ridges of the trunk bear large warts
or knobs, and there are small warts and dots all over the surface.
Size, about l/60th inch.

I found this fine large species several years ago, but have
never met with it since. Mr. Murray also found it in some moss
I sent him from the same gathering in which I discovered it.
Unfortunately I have lost my notes on it, but from the sketches
I still have, and the sketches Murray sent me, and a few marginal
notes thereon, I am able to give sufficient data for purposes of
identification.

It is in some particulars like M. russeola — in spurs, upper lip
and general build — but it has a most extraordinary peculiarity,
the possession of three kinds of processes ; very large warts or
knobs along the trunk ridges, from five to seven in each ; and
smaller sub-hemispherical warts and fine dots in extraordinary
numbers all over the surface. The large warts consist of a bundle

JouRN. Q. M. C, Series II.— No. 79. 12

156 W. MILNE ON THE

of threads or possibly tubes, and are well seen from the side view
(fig. 5c). From the front view each has an alveolar appearance

(fig- 5d).

There is a curious growth in the neck.

Murray suggested the name Gallidina faveolata, so I have re-
tained it. I have no record of the nature of the toes, but I think
it quite possible that it may have to be transferred to the genus
Mniobia.

Habitat. — Rock moss, Euphorbia Kloof, Uitenhage district.

A fair number were seen in one gathering of moss. I have very
often examined moss from the same place, but never had the
good fortune to find the animal again.

Genus HABROTROCHA BRYCE.

Habrotrocha placida sp. nov.

PI, 11, figs. 6-6c.

Specific Characters. — Of moderate length, very narrow and
hyaline in colour. Narrow rostrum with double lamella. In-
closed wheels characteristic. Antenna very short — about one-
third neck width. Teeth about eight, very small. Spurs, short
cones without interspace. Corona is equal to two-thirds of the
width of collar, and the pedicels are extremely short. Upper lip
is bluntly triangular with large elbow-bends directed backward.
Trunk is lightly stippled. Size, l/90th inch.

This species is of a quiet, gentle habit. When placed on the
slide, it may not begin feeding for a very long time, but when it
does it will remain in the same position for hours, without any
swaying movements, but keeping the corona perfectly steady, or
shifting the head almost imperceptibly ; when it does creep it
does so gently and not with jerky motions.

The distinctive features are the corona and the upper lip. The
corona is to the collar as 4 : 6. Its wheels have scarcely noticeable
pedicels, and the primary wreath being thus so near the secondary,
the interference due to their vibrations makes it difficult to observe
the upper lip. The upper lip is triangular and is raised at a
slight angle to the wheels. A short distance from the front each
border makes an elbow-bend backwards, and uncovers its base,
which is seen as a straight line. The bends can be seen high
above the collar when viewed laterally. Sometimes when the

BDELLOID ROTIFERA OF SOUTH AFRICA. 157

animal is apparently anxious to feed, it may be seen hesitating
and evidently dubious about the advisability of unfolding the
corona. On these occasions the upper lip is pushed stealthily
forward, with its elbow bends compressed backwards into sharp
angles, and the ends of the collar apparently thrown forward
(fig. 6c). The corona is not yet unfurled, but the rostrum is
thrown back.

When creeping it appears long and narrow, and makes a short
gentle glide.

The inclosed wheels are a glaucous mass with a clear-cut
outline, small and round with a flattened front. The lateral
plicae are well marked ; and the cross dorsal marking, from
which the lumbar plicae spring, is unusually far forward.

When feeding, the front trunk segment usually stands well out
from the neck (fig. 6). It feeds in the open. The jaws are
large, but the teeth are very small and difficult to see clearly, and
are possibly more than eight in number. The lumbar region is
not unlike that of Otostephanos torquatus-amoenus, and indeed
it is difficult to distinguish between the two species when
creeping. I usually look first for the long setae at right angles
to the rostrum which characterise 0. torquatus-amoenus.

Habitat. — Ground and rock moss, Kamaehs, Euphorbia Kloof
and Springfield. It was fairly abundant.

Another rather smaller form and probably a variety of the
above was seen. The corona was very slightly wider, and in the
upper lip the front part of the elbow-bend — if bend there were —
could never be certainly made out. Otherwise it had the same
appearance. It was deeply stippled. The number of teeth was
probably seven.

Habrotrocha plana sp. no v.

PI. 11, fig. 7.

Specific Characters. — Short and broad with narrow extremities
of a bluish-grey colour. Lamella double with several long setae
under it. Antenna from one-third to one-half neck width.
Jaws large, teeth two, very small. Trunk very broad and slab-
like ; lumbar region of distinctive shape. Foot has possibly
four segments, a very narrow ankle and stout toes. Spurs short.
Contractile vesicle is large. Corona less than collar. Upper lip
triangular. Size, 1/lOOth to l/120th inch.

158 W. MILNE ON THE

This is a tremendously swift creeper, and slithers or glides
fully its own length before planting its toes. It is very steady
when feeding, and generally feeds in a fully extended position.
Every now and again, it suddenly glides along for a step or two
and recommences feeding, and may keep on repeating this per-
formance for a long time. The suddenness with which, on these
occasions, it unfolds its corona and is quietly feeding again is
almost startling. The pellets are often large and numerous, but
sometimes scarcely distinguishable in a glairy mass.

The trunk is very broad, and flattened dorso-ventrally ; and
seen sideways has a slab-like appearance. The rump is peculiar,
the fleshy parts are wrinkled inwards in two waves, leaving the
remainder empty and glassy looking.

The corona is to the collar as 9 : 10. It has a seta on a small
pimple on each wheel. When looking do^\^l on the sulcus a
cord-like rim can be seen on each side, running over the edge and
on to the w^heel, just showing and no more, an apparent clear
space between it and the wheel.

The upper lip is triangular, its two sides just visibly curved,
and does not rise far up the sulcus. It is clear and glassy,
and rises gradually from the two borders and the apex, towards
the middle of the front of the rostral segment, somewhat like
part of a dome. The rostral segment during feeding is very
rounded dorsally, it bulges up from the sides, up to and round the
rostrum, which occupies the greater part and stands well up, the
whole having a sort of inverted-saucer appearance.

The foot has very heavy glands which pass through the anal
segment. The spurs sometimes resemble a fish tail, but are
usually short cones, scarcely divergent, and without interspace.

//. j)ulchra (2) is the nearest to this, but differs in the
upper lip and the number of teeth.

Habitat. — Ground and rock moss ; common in Uitenhage
district ; also found in Grahamstown.

Habrotrocha iners sp. no v.
PL 11, figs. 8-8c.

Specific Characters. — Of moderate size with long neck ; hyaline
in colour. Rostrum very long and narrow ; lamella single.
Antenna very long, one-fourth longer than neck width. Teeth
three, fairly large and uniform. Lumbar region heavy. Foot

BDELLOID ROTIFERA OF SOUTH AFRICA. 159

very short, of three segments. Spurs fairly long, almost parallel.
Corona one-half wider than collar. Oral entrance has a great pro-
jecting spout form. Upper lip very distinctive. Size, l/80thinch.

This is probably a tube builder, but none was ever seen in a
case. The older specimens were very sluggish and hardly ever
moved from the place where they were first seen. They are far
from being of the 7nusculosa-tyi^e, as the trunk runs and streams
into all shapes when feeding. At first I decided it was a Mniobia.
In the first example observed the foot was planted against
the cover-glass and the spur segment was seen to have a slight
expansion at the end (PL 11, fig. 8c). There seemed to be clusters,
two or three, of very fine muscular sucker-like threads from the
end and no sign of toes. Later, however, a young specimen was
observed creeping against the cover-glass, and showed toes very
distinctly, two well spread out, and evidently a smaller one though
not well distinguished. It progressed at rather a slow rate, with
a rasping dead pull. The pre-intestinal part appeared fully as
long as the rest of the body.

The rostrum is somewhat of the nature and appearance of that
of Rotifer longirostris. It is as long as the width of the neck,
and is very narrow and of practically uniform width. The joint
in the middle is very distinct. In the older specimens when
attached, the rostrum has generally an empty appearance, and
the sheath is peculiarly mica-like. The skin of the neck occasion-
ally has this wrinkled mica appearance ; when young the neck
is fleshy, and the rostrum lacks much of this appearance. The
young was seen to bend the rostrum at right angles to the body,
and to twist it about easily, as if it were fitted into a socket.
The lamella is single and spoon-shaped. The inclosed wheels
are elongated. The antenna is very long — one and one-fourth
times the neck width — and it is very narrow from the joint to
the end ; and has a stout bunch of setae in the middle of the
extremity.

The antennal segment is longer than usual. Behind the
antenna, and not alongside, are two peg-like projections, ap-
parently cone-shaped in one view, and triangular in another.
They rise direct from the segment with no ridges or connection
between them. H. amfulla has similar prominences. The jaws
are long and rather narrow, and bear three teeth on each side,,
fairly large and uniform in size.

160 W. MIlNE ON 'THE

There is a large and round intestine, and the contractile vesicle
is rather small and of short period. The short foot consists of
three segments. Spurs are of moderate length, slightly shouldered
on the outside at the roots, and then proceed downwards with a
slight convex curve. They are not divergent.

The corona is a very pretty one, with strong cilia which play
to a considerable extent into the great oral entrance. In some
views it reminds one of some lily in bloom with its long stalk and
bulb ; the long rostrum and antenna standing out well, almost at
right angles, contribute to the elegant outline. The corona is
to the collar as 9 to 6 and is much inclined ventrally. When the
neck is bent dorsally, till the plane of the wheels is horizontal,
the ventral view shows the great oral entrance-spout standing
straight up, and well above the level of the wheels (PI. 11, fig. 8b).
This large spout-like mouth is very similar to that of H. angustu
collis (2).

The upper lip is a thin -looking, glassy, laminate plate, rising
well up, broad and curving slightly outwards, and crowned with
a flat triangle.

When the neck is bent, rings are formed simulating joints, and
even in the rostrum a false joint may appear. When the animal
is contracted into a ball, the head is seen attached to the front
of the trunk by about a score of delicate muscular threads,
parallel and stretched like piano strings.

A yellow case was seen frequently, and only where this animal
was found ; empty, except in one instance when there was an egg
inside. I did not see it hatch out, but soon after it did I found
a half-grown specimen on the slide, which I had not observed
before, and which probably came from the egg. The case is
almost round in shape, and has no neck. It has a hard thin wall
with granules in it, and there are about a dozen rings or bars
projecting on the inside, looking like lines of latitude on a globe.

Habitat. — Draaifontein farm ravine pools. Found in fair
numbers, on different occasions, but only from the one place.

Habrotrocha valida sp. nov.
PI. 13, figs. 16-16a.

Specific Characters. — Of small size, short and very stoutlv
built. Hyaline in colour, but older ones occasionally have the
stomach coating slightly brown. Eostrum short and thick;

BDELLOID ROTIFERA OF SOUIH AFRICA* 161

lamella single, undented. Antenna about one-fourth neck
width. Teeth large, six. Foot short, stumpy, of probably
four segments. Spurs very short cones without interspace.
Corona is narrower than the collar ; sulcus a mere slit. Upper
lip rises to the top of corona, large, with a broad straight front
margin and a parallel distinct ridge well back. Size, up to
1/lOOth inch.

This is quite a handsome sturdy little animal. It is fleshy
in appearance, and the distinction between the segments is not
always easily discernible. It is a voracious little creature, and
soon the dozens that may be seen in a slide settle down to feed,
and very quickly the trunks assume barrel-like forms, so that
when they then creep they have a trussed-fowl or penguin-like
appearance. The shape when feeding is characteristic, all being
alike. It is a fast traveller with a long stride, but usually it
moves about very little, and remains very quiet for long periods
when feeding, and is not easily disturbed. The rostrum is stout
and the lamella is single and undented, transparent and almost
semicircular. The dental bulb is comparatively large, and the
six closely set teeth can be readily seen.

The lumbar plicae are not very prominent. There are heavy
foot-glands, and the spurs are very short, non-divergent and
without interspace. Each has a very broad base, and quickly
narrows to a sharp point, with a straight line, or barely per-
ceptible double curve on the inner border.

The corona is small and has very short pedicels, and the outline
does not narrow in, on the lateral borders. There are two little
prominences on the wheels close to the sulcus ; these seem to be
small loops, or swellings on cords or ridges from the wheels,
running down over the inside edges just into the sulcus, which is
a mere slit. The corona is to the prominent collar as 5 to 7.
The upper lip rises, practically, to the top of the sulcus, with a
very broad, straight front margin, and there is a band or ridge
parallel to the front margin, and well back. This ridge seems to
rise up from the lateral borders of the upper lip. Both ridge
and front margin look bluish green while the rest of the lip is
colourless.

The egg is an oval, equally rounded at both ends and smooth.

Habitat, — Ground moss, Stellenbosch. Very abundant from
the one place only. Dozens were sometimes seen on a slide.

162 W. MILNE ON THE

Habrotrocha alacris sp. nov.
PL 12, figs. 14-14a.

Specific Characters. — Very small and narrow ; hyaline. Ros-
trum long and narrow, Avith double lamella. Antenna stout,
about three-fourths neck width. Jaws large with two large
teeth. Rump distinctly marked off from the trunk. Spurs short
cones. Corona is wider than collar. Seta on pimple on each
wheel. Sulcus equal to half the width of wheel. Upper lip a
small rounded segment on a flat curve. Size, 1/1 20th inch.

This little animal creeps fairly fast, but steadily and without
slithering. It assumes very graceful curves when feeding.

The dental bulb is large, and with its muscular investment
takes up, practically, the whole width of the segment. The
two teeth are also quite large. The trunk is very plicate. There
is a distinct marking oft' of the anal and pre-anal segments from
each other and from the trunk. The intestine is large and
elongated, but the contractile vesicle is small. Spurs are equal
to the ankle width, divergent and without interspace.

The corona is fully one-fourth wider than the collar, and the
pedicels are very long, so that the general appearance of the
corona is a little like that of H. eremita or H. acornis ; only the
distance between the pedicels inside does not increase upwards,
and the distance from the sulcus bridge to the top of the corona is
comparatively greater. There is a small round knob — not a
ligule — on the sulcus bridge. The semicircular upper lip rises
just up to the sulcus bridge ; and the collar, above which there
is a lateral expansion, shows very prominently.

Habitat. — Ground moss, Springfield, Uitenhage district. Not
common and found only in moss from the one place.

Habrotrocha elusa sp. nov.

PI. 11, figs. 9-9a.

Specific Characters. — Of moderate size, rather stoutly built
but not swollen looking ; keeps its shape well. Of a brownish
to dark lemon-yellow colour. Rostrum stout, lamella double
and prominent. Antenna short, equal to one-third neck width.
Teeth six. Skin smooth and thick. Shape of rump and first
segment of foot very characteristic and constant. Spurs two

BDELLOID ROTIFERA OP SOUTH AFRICA. 163

short cones, with flat interspace. Stippling heavy over all
trunk and foot, first segment of foot heaviest of all. Corona
fully equal to collar ; sulcus very narrow. Upper lip large,
right to top of corona, with a small notch in front. Size, up to
l/75th inch.

This is a stout and very symmetrical animal with thick, leathery
but smooth skin. It is of the musculosa-ty^e as regards the
quick response to the action of the muscles, so that in whatever
position it is the shape for that position is practically constant.
The neck is extremely stout and fleshy, and its outline is made up
of three graceful curves not broken by the joints.

The corona is fairly large, but is rather difficult to measure. My
measurements are, corona to collar as 9 to 9 up to 10 to 9.
The average would be about 10 to 9 J.

The rostrum covers a large part of its segment when tossed
back. There are six teeth on each side of the dental bulb, three
large and three small. The small teeth are difficult to count, but
in the instances where I could count them the number was three.
The trunk is fleshed right up into the ridges, and shows dense
round the borders, where a considerable depth of skin is seen
owing to the boundary bend. This dense leathery shell or
rind-like part contrasts with the interior, and has a dark-greenish
tinge, like that described in Otostephanos regalis. It often acts
in the same peculiar way as 0. regalis when, having stopped
creeping with the intention of feeding, as shown by the
working of the jaws, and as if too timid to decide, it starts a
panting sort of action with a queer little shake of the head
up and down, and may continue this for a long time, before it
unfolds the corona. When it feeds, the head is kept very
steady, and the foot is generally hidden under the rump.

The form of the rump is constant. There are three folds of
the thick skin on each side bulging out between the joints, or
apparent joints. The middle one looks something like the
prominence shown in the figure of H. crenata (Murray) (2, 3).
All the rump — bulges included — is heavily stippled or granulate.
I have never seen any crenate appearance even on the first
segment of the foot, which is the most heavily granulate part.
Evidently the granules are under the skin. The foot has four
segments ; the first is stout and curves out very delicately till
past the middle, and then curves inwards much more quickly.

164 w. MILNE ON m-E

The second segment is much narrower and very short, and seldom
much seen. Young specimens have seldom any colour, but can
"be identified by the foot. There is no boss on the foot; the
elegant dorsal curve of the first segment is quite unbroken, though
there is a thickening under the skin, like that described in
H. torquata (8). The spurs are short cones often stippled, very
diver«^ent, with a straight fairly wide interspace. Occasionally
the under border of the spurs may be seen in a straight line
with the interspace. The contractile vesicle is large, and flattened
posteriorly.

The egg is large, smooth and oval in shape, equally broad at
both ends.

I have known this animal for many years and have spent more
time examining it than any other species. For a long time I was
unable to form definite conclusions about some points, and not
until it was noticed that there were two species not very unlike in
several details. The second one, which turned up occasionally
with H. elusa, is paler and more lightly stippled, but for some
time I thought that the type varied and included both.

H. elusa is not sluggish, and when put on a slide creeps about
a great deal, and usually takes a long time to settle down to feed.
After hours, it may be, one may stop and feed for a short interval
and then resume creeping. It may be the second or third day
before it begins to feed steadily, and then it does so very quietly,
and in a characteristic position. If there be a bit of green moss
about, H. elusa is almost certain to take refuge on or below it,
and remain there. It is then almost impossible to get it clear.
I do not think I have ever noticed it take refuge under withered
moss. It feeds very freely on or under the moss, but there, of
course, it is not possible to observe it clearly. It is also found
feeding quietly in the open. I have often taken notes of one
creeping and been unable to see it feeding during the same
sitting. Before the next examination the specimen had pro-
bably retreated to the moss, or could not be found feeding. Then
perhaps what was taken to be but a paler example was found
feeding, and a sketch made, which when compared with former
sketches usually showed some difference, especially as to upper
lip and spurs. I changed my opinion several times with regard
to these until I distinguished between the two species. A diffi-
culty was, that one or the other was often not to be found when

BDELLOID ROTII'EilA OF SOUTH AFRICA. 165

wanted for comparison. Afterwards it became quite an easy-
matter to distinguish between the two, creeping or feeding.

H. elusa generally feeds with its head above the horizontal,
and the tip of the upper lip is not then seen projecting at the
front, but lies over the narrow sulcus, which usually shows a
black space owing to interference, when practically no details can
be made out. When the head is exactly on a level with the body
the peculiar nature of the upper lip may be seen, but as a rule
it requires much patience and needs much searching before one
is observed feeding at the right angle. The lip is fairly broad in
front with a small notch in the middle. Laterally there is a fold,
from the top corner to some distance down, turned in over but
not quite down on to the rest of the upper lip, leaving a space
below running into the corner.

The rump is very distinctive, with the triple folds of skin on
each side. The middle one is the largest and recalls H. crenata,
but the prominence in the latter does not seem to be a wide fold
of the skin — from the description — and is stated to be clear of
stippling, whereas the folds in H. elusa are heavily stippled like
the rest of the rump.

The first segment of the foot is sufficient to distinguish H,
elusa from other species.

I do not think I have ever seen H. crenata, but there is evidently
a resemblance in its general outline to that of H. elusa. The
different type of upper lip, however, is alone enough to show that
the two are distinct species.

H. elusa differs in many points from the description of H,
crenata by Murray.

The corona of the former is proportionately much wider, and
the front margin of the upper lip is quite different, having a
notch.

It has a decided colour, whereas H. crenata is colourless.

It never has a crenate appearance, and the stippling is most
pronounced on the first segment of the foot, while in H. crenata
it diminishes on the foot.

The rump has three folds of thick skin and all stippled. In
H. crenata there is but one round prominence, which is stated
to be free of stippling. H. elusa has no boss on the foot and its
spurs have a straight interspace. The inclosed discs are large.
The egg is not narrowed at the anterior end. H. elusa is not

166 W. MILNE ON THE

sluggish. Murray does not mention H. crenata as having been
found in South Africa. If it had been as common as H. elusa,
I think he was certain to have seen it.

Habitat. — Ground, rock and tree moss, Uitenhage district (all
over), Umtata, Somerset East and C4rahamstown . Very common.

Habrotrocha elusa var. vegeta.
PI. 12, fig. 10.

Specific Characters. — Active, rather small, colourless. An-
tenna short. Neck stout and fleshy, with same outline as
H. elusa. Teeth three large and four small ones — possibly more.
Trunk plicate ; stippled, as are also the rump and foot. Rump
fairly heavy, without prominences. Foot of four segments ;
first segment long wuth straight borders. Spurs short cones
without interspace. Corona less than collar. Upper lip narrow,
rounded in front and with a slight groove. Size, l/90th inch.

This jaunty little animal creeps fast with a short glide. It
usually does not take long to settle down to feed. It can be kept
healthy for a long time in a slide, and is generally seen actively
feeding. Its manner of feeding is very like that of H. plana.
It suddenly glides a step and is feeding again with startling
rapidity, and keeps on repeating this performance at short
intervals ; but also it may remain feeding in one position for a
very long time. The head is sometimes kept very steady, but
usually is drawn very slowly up and down, or round and back.

The upper lip is more difficult to observe than that of H.
elusa, being narrower at the front, and hardly projecting over the
sulcus. I only once or twice got a really good view, such as
made clear the details. Nearly always the blackness due to
refraction in the sulcus obscures the parts. The tip is bent
downwards, and there is a cross line or ridge, a little back.
From the middle of this a minute groove proceeds to the front ;
but it would appear as if the groove does not penetrate very
deeply into the substance of the upper lip, and probably does
not reach the bottom at the tip, so that at certain angles no
gap is seen in front, while at others a minute gap appears.

It nearly always feeds fully extended.

I find this animal in fair numbers in Aberdeenshire.

The chief differences between it and //, elusa are : The glide

BDELLOID ROTIPERA OF SOUTH AFRICA. 167

when creeping ; the want of colour ; the corona is, pro-
portionately, decidedly narrower ; rump has no prominences ;
foot has plain, straight outline ; spurs have no interspace. It
feeds with neck and foot fully extended, whereas //. elusa lies
over the foot, and always has the neck partially retracted, so
that each segment shows decidedly wider than the one in front.
Habitat. — Ground and tree moss, Umtata, and Uitenhage
district.

Habrotrocha tranquilla sp. nov.
PL 12, figs. 11-lla.

Specific Characters. — Large and shapely ; stoutly built. Ros-
trum stout with prominent double lamella. Antenna short,
about one-third neck width. Dental bulb large, oval. Teeth
seven. Trunk plicae well marked. Rump fairly heavy, narrows
quickly to foot. Foot narrow and short, of four segments.
Spurs sharp cones, divergent, and without interspace. Corona
slightly wider than collar ; sulcus narrow. Upper lip projects
over the sulcus, and has small gap in front. Size, l/60th.
inch.

This is a large handsome animal, and occasionally shows the
merest tinge of colour. The trunk is very long, and when feeding
swells out like a muscular sack ; the pre-intestinal part is com-
paratively short, and the post-anal very short. The posterior
of the trunk and the rump are eccentric, raised dorsally, so that,
if the toes miss the catch, the posterior swings round, and at
times, when welLie^, it seems compelled to shoot out the foot
sideways.

Of the seven teeth, four are large and three very small. The
corona to collar is as 13 to 10. The upper lip is fairly broad at,
the top and has a small gap. It projects over the sulcus, but
not quite so high as the outside parts of the wheels. The upper
half is almost oblong, and then the border bends quickly, in
two curves, to the collar. The front margin is somewhat like
that of H. elusa, but the details are more easily made out.

I find this species in Aberdeenshire with slight variations.
The corona is slightly narrower, and I counted nine teeth. There
was a boss on the foot. I might, however, have overlooked this
characteristic in the South African species, as I did not pay much

168 W. MILNE ON THE

attention to bosses at the time I found it. Otherwise, the two
agree extremely well.

Habitat. — Rock moss, Kamaehs farm, Uitenhage district.

Habrotrocha pertinax sp. no v.
PL 12, figs. 12-12a.

Specific Characters. — Very small, narrow at front and widening
gradually to the rump ; hyaline. Rostrum narrow with promi-
nent double lamella. Antenna short, about one-third neck
width. Teeth three to four, quite large for pellet makers. Rump
heavy. Foot of apparently three segments. Spurs sharp cones,
divergent, no interspace. Corona to collar as 4 to 7J. Sulcus a
mere slit. Upper lip a broad mass rising right up, and projecting
slightly over back of wheels. Trunk clearly stippled. Size,
1/1 20th inch.

This is an active little animal. It keeps on for a long time
creeping fast with a slither or glide, sometimes for hours without
resting. It is so small that it is quite easily overlooked, and
when searching particularly for it in a new slide I hardly think
I ever found it, as it apparently keeps out of sight in the debris,
or rolls up in a ball after being disturbed. Only after a day or
two, when examining the slide, by chance one might be caught
sight of in the open.

The corona is scarcely more than half the collar width. When
the head is thrown back it has the appearance of Scepanotrocha
(5), as then the edges of the wheels just show above the big
upper lip. Seen horizontally, the upper lip is a broad mass right
up to the top of the corona, but seems to turn slightly in at the
middle. The edge of the upper lip, rising up from the collar,
seems to just pass over the back of the wheels, and to form a
sort of cradle for the back of the corona. When it is feeding
— lying on its back — with the head bent up above the hori-
zontal, the square, broad outline of the upper lip can be seen
just above and behind the wheels, also the part mentioned above
appears triangular in outline over the wheels. It usually stands
straight up on its toes when feeding, and keeps in one position, or
very slowly turns its head ; it keeps stretching and stretching
till sometimes the length is considerably greater than the creeping

BDELLOID ROTIFERA OF SOUTH AFRICA. 169

length. It may keep on feeding for a long time, and different
views are obtained as it turns its head, but being so small the
details are not easily made out. There is no play of cilia dorsally,
but a great flutter round the pedicels towards the oral entrance,
and straight up above the corona.

Habitat. — Ground moss, Springfield. Only seen from one
place, and, from the number actually seen, apparently fairly
abundant.

Habrotrocha gulosa sp. no v.
PL 13, figs. 15-15b.

Specific Characters. — Of fairly large size ; hyaline in colour,
except that the pellets are usually bright yellow or green. Ros-
trum stout and long. Antenna as long as one-third neck width.
Teeth three, fairly large. Anal segment long, with large con-
tractile vesicle. Foot slender and short. Spurs short cones with
fairly straight interspace. Corona as wide as collar, with narrow
sulcus. Upper lip a wedge rising from a flat curve. A seta with
a bulbous root on each wheel. Trunk heavily stippled. Size,
l/75th inch.

This is a gluttonous animal, and in a very short time, when
feeding, becomes crammed with pellets. It is heavy towards
the end of the trunk and lumbar region, and when well fed
becomes very much so, and penguin-like. When it begins to
creep after a heavy meal, its balance is so disturbed that on
letting go with, the toes the lumbar region swings round, and
the toes catch on the right or left as the swing allows, and are
occasionally pulled quite up by the trunk falling right over to
the one side or the other. It is a laborious business on such
occasions for it to progress. At times it creeps fairly fast with
a glide. When feeding it sometimes starts off swimming at
tremendous speed, and may keep this up for some time.

The inclosed discs show a bold clear outline. I could not make
out more than three segments in the foot.

The corona bears strong cilia which vibrate swiftly, and often
make quite a haze round the wheels. The under lip is of a blunt
spout-like shape, and projects a fair distance. The upper lip
ja often hidden by the rostrum^ and is quite peculiar in shape.

170 W. MILNE ON THE

A narrow wedge-shaped ridge risfes up from the middle, just on to
the sulcus bridge. This ridge is not straight up and down, but
bends in with a sharp curve, at the top, over the sulcus.bridge.
The sharp edge of the wedge is dorsal, and curves round over the
top, so that looking down dorsally, with the animal horizontal,
a sectional view of the top of the wedge is got, looking like a very
short stout ligule, apparently on the sulcus. It was thought at
first to be a ligular process. Seen from the side the wedge shows
broader (fig. 15).

The egg is ovoid, both ends broad and equal.

Habitat. — Ground moss, Uitenhage commonage (Mosel Road)
and Springfield. Fairly common.

Otostephanos gen. no v.

Type. — Otostephanos auriculatus (Murray) = Habrotrocha auricu-

lata.

Generic Characters. — Bdelloida having a ring of fair thickness
round the corona with short breaks dorsally and ventrally.

Whether the ring is real or false, the appearance is so distinctive
that there is no difficulty whatever in identifying a species as
belonging to the group, after one is once known. It is easy
enough, with the 1 inch objective, to distinguish whether a
corona is ringed or not, even if it be one whose diameter is only
l/900th of an inch.

Bryce (8) is of the opinion that the ring is a ghost one. Murray
(7) thought it real ; to me it seems real enough. I cannot
satisfy myself that the explanation that the ring is due to inter-
ference is sufficient, as for one thing there are many coronae
which have no rings, whose disposition of the primary and
secondary wreaths appears in nowise different from that of those
which have. Also, as Murray states, there is no trace of motion
in the ring, and the outline can be very clearly defined.

There is difficulty also in accepting the ring as real. From
the lateral ear or loop appearance the ring seems to stand clear of
the corona, but the ring possibly has a connection through a
transparent membrane, the ring itself only being visible on
account of its thickness. The ring seems close to and connected
with the corona alongside the sulcus and also at the dorsal break.

BDELLOID ROTIFERA OF SOUTH AFRICA. 171

Otostephanos regalis sp. no v.

PI. 14, figs. 19-19b.

Specific Characters. — Large ; of a lemon colour generally.
Rostrum stout and long. Antenna fully equal to half neck
width. Dental bulb long and narrow, with six teeth. Heavy
rump and short stout foot of four segments. Spurs short cones.
Trunk deeply plicate, and stippled. Corona about one-fourth
wider than the collar ; sulcus narrow and shallow. A seta on
each wheel. Upper lip a semicircle set on a ba^se with a ligule
on the top. A steady feeder. Size, l/65th inch.

This is a large, powerful animal. It is a swift creeper, and a
bold feeder in the open ; and is very symmetrical, with a dis-
tinctive shape both creeping and feeding. It is of the musculosa-
type and recovers its bold curves and lines almost instantly, not
sagging anywhere, as the leathery skin is thick and elastic.
Focusing down to the middle-depth of the trunk, the outline,
owing to the depth of skin under view all round the margin,
stands out with a dark-greenish shade on account of its density,
and shows like the rind in a sliced citron fruit. The circular
muscles are very distinct.

The colour varies, usually lemon all over — deepest in the
ovary — but sometimes of a pinkish yellow. The trunk, rump
and foot including the spurs are heavily stippled, the first segment
of the foot more especially so.

Corona to collar is as 12 to 9 J. On each wheel is a short seta
with a bulbous base on what looks like a raised cone, but is
evidently a triangular ridge across the wheel. The setae are
inclined towards each other. There is a rosette round the closed
mouth.

The ring in 0. auriculatus, Murray (7),^s stated to have a break
or gap laterally. There is an apparent gap in the ring of 0. regalis,
but not a real one. The lower part projecting from near the
collar (dorsal view) does not belong to the ring, but is the secon-
dary wreath or rather the base supporting it ; and if it were
continued through the apparent gap, w^ould form a continuous
curve with the upper part, and thus accentuate the idea of a
break. The lower part (secondary wreath) is not a broken line,
but bends back almost on itself, or at most at a sharp angle, and

JouRN. Q. M. C, Series II.— No. 79. 13

172 W. MILNE ON THE

then across to the oral entrance. The upper part of the ring
comes down to near the bend of the secondary wreath and con-
tinues close, past and above it. When a slightly more ventral
view is had, the two can be seen alongside each other for a short
distance, but the continuation of eacK curve in its own direction
gradually separates.'Xhem. i.

The ventral view (fig. 19b) shows the real relative positions of
the lines well. The ring rises from the hollow below the shallow
sulcus, and can be followed round to the apparent gap, as can
also the base on which the secondary wreath is situated. The
two seem to approach each other towards the gap.

When the head is hanging down, well below the horizontal,
the three planes — top of corona, ring and secondary wreath — can
be seen projecting, one behind the other.

The upper lip is like no other I know. It shows like a clear
transparent semicircle, with a metallic sheen, set on or rising
from a flat curve from the collar. A stout peg-like ligule rises
from the top and is always present. The rostrum has its segments
marked very clearly, and the double lamella is very transparent
and sometimes not very well seen, though quite large. There are
several long setae and one or two thicker ones with bulbous roots.
When tossed back the rostrum stands up perpendicular to the
segment as a great mass and covers nearly all the segment ;
the cilia are generally in motion.

The dental bulb is long and narrow, and carries three larger
teeth and three, possibly four, very small ones. The first joint
in the neck posterior to the oral entrance is scalloped or serrated
roundly, ventrally ; and the anterior of the second trunk segment
has a similar appearance.

The pellets are occasionally seen fairly large, but generally
quite small, and at times can hardly be distinguished in a thick
glairy mass. The foot is very short ; the first segment is heavily
granulate, the second is scarcely noticeable, so short is it. The
spurs are slightly divergent short cones, but in one or two large
examples the inner borders showed a slight double curve. There
are heavy glands right up through the foot.

When settled and about to feed, it has a very peculiar quick,
panting sort of action, with a queer little throw-up of the head, the
jaws working all the time. It may keep this up for some seconds
before unfurling the corona.

BDELLOID ROTIFERA OF SOUTH AFRICA. 173

Habitat. — Rock and ground moss, Kamaehs, Springfield and
Euphorbia Kloof in Uitenhage district. Fairly common.

Hahrotrocha torquata Bryce I have never seen, but from the
•description take it to be one of the ringed group, and so it falls
Tinder the designation Otostephanos torquatus.

There is a ringed one, very common in bouth Africa, similar to
the above but differing in the upper lip. I shall describe it as a
variety.

Otostephanos torquatus (Bryce) var. amoenus.

PI. 14, figs. 20-20a.

Specific Characters. — Of moderate to small size ; spindle-
shaped ; trunk slightly grey, or bluish, transparent. Rostrum
long and fairly stout, has a very long seta on each side at right
angles. Antenna equals one-half neck width. Teeth very small,
seven, possibly more. Trunk plicate and finely stippled. Fairly
lieavy rump, and short foot of four segments. Spurs, short
■cones. Corona is equal to the collar ; sulcus very narrow and
shallow. Upper lip has three blunt points on it. A seta on each
•disc. Size, l/85th inch.

This animal generally creeps about a great deal at first, when
put in the slide, but eventually settles down to feed very quietly.
It is not a very fast creeper, and occasionally seems to have to
rasp its foot from the glass with a steady pull. The rostrum has
■several setae under the lamella, and there is one on each side at
right angles to the rostrum, fully longer than the width of the
Tostrum. Though pliable, they were not distinctly seen to be
motile. I think these setae cannot be borne by 0. torquatus, as
Eryce was hardly likely to have overlooked them if present. The
neck is stretched out when feeding, and generally with the head
hent up.

The dental bulb is small, and the teeth are so small that they
^re seldom distinguishable at all with a l/6th inch objective,
when the animal is feeding. The rump is fairly heavy and
•distinctive, and the first segment of the foot is also distinctive,
the sides being curved. The spurs have no interspace.

After some experience, it is not very difficult to identify the
creeping form. H. placida has a general resemblance, and is
often found feeding with it, but one has only to look for the

174 W. MILNE ON THE

long setae at right angles to the rostrum, which if present indicate
the variety amoenus.

The upper lip almost curves down for some distance from the
collar, then turns quickly upwards with a graceful curve to the
fairly broad front, which, when the head is on a level with the
body, shows three minute knobs. When the head is raised some-
what, a rounded part is seen in front, and also the triple part above
and behind it. The upper lip does not lie flat on the corona, but
stands up at a considerable angle, so that the rounded part
mentioned above may be the under side of the lip raised up and
backwards so as to come into view ; or, as I have sometimes
thought, there may be two parallel membranes, the front one
plain and the back one with the triple top.

The setae on the middle of the wheels turn outwards, while
in 0. regalis they turn inwards.

The inclosed wheels have a clear-cut border, forming a single
oval, with practically no trace of the usual double appearance.

Habitat. — Kock and tree moss, Uitenhage district and Stellen-
bosch. Abundant.

Otostephanos monteti sp. nov.
. PI. U, figs. 21-21a.

Specific Characters. — Of small size, short, plump and fleshy ;
of glaucous colour, with at times a very slight yellowish tinge^
Rostrum short and broad, with prominent double lamella.
Antenna very long. Dental bulb elongated, with eight small
teeth. Foot of four segments. Spurs, cones of moderate length.
Corona equal to collar, shallow, with prominent ring. Sulcus a
mere slit ventrally. Upper lip, rectangular with a ligule-like
extension on upper border. Size, 1/lOOth inch.

The two species last described are moss dwellers, but this one
inhabits pools. It is a rather slow creeper and has a laborious
movement of the foot, but plants it well forward ; it seems to
have a difficulty in attaching it to the glass. This animal is
most irritating when feeding. As soon as the wheels are out, it
begins whirling round and round on a vertical axis, at great
speed, and continues this for many minutes at a time, then
suddenly with a furious dart it swims clear away. Only once

BDELLOID ROTIFER A OF SOUTH AFRICA. 175

did I see a specimen feeding quietly with toes affixed, and that
not for very long. On several occasions I was hopeful of getting
another view, but hardly had feeding commenced when the
gyrations were once more started, before anything could be
clearly seen.

It is of a sturdy build. The neck is very stout and fleshy,
showing no lacunae ; and the throat is wide and long. The
inclosed wheels are a large clear mass, nearly circular in shape,
with a small break in a clear definite outline. The closed mouth
shows a well-marked rosette.

This is the only ringed form yet observed which has a very
long antenna. It was not noticed for some time that the antenna
was long, as seldom or never does it seem to have it at full stretch
when creeping. When attached to the cover-glass and about to
feed, and moving the head forward preparatory to unfurling the
corona, the antenna is pushed straight in front, and when at full
stretch is well ahead of the rostrum ; and when the wheels are
out it is seen projecting for a considerable distance in front of the
wheels and straight over the sulcus. It has been seen extended
to fully one and one-fourth times the width of the neck. When
the animal is whirling round and round, the antenna is held
outwards, with the end curving backwards, and gives a fleeting
glimpse, reminiscent of a pump handle, as it swings round. Of
the two segments of the antenna, the front one is not much
shorter than the basal one, and the front end with its brushes of
stubbly setae is very trident-looking. There is a large brain
mass. The jaws are long and somewhat oval, and bear eight
small uniform teeth.

The foot is stout and proportionately long, and consists of
four segments. The spurs are less than ankle width, scarcely
divergent and without interspace.

The corona is equal to the collar in width, and rather shallow.
The collar is high up but does not protrude, and there is no narrow-
ing-in of the neck from the collar backwards.

The upper lip is a low rectangle with rounded shoulders ; and
in the middle in front, extending up as a prolongation, is a long
spike with a broad base, which gradually attenuates to a sharp
point near the top of the corona.

This animal is easily distinguished from O.torquatus vaT.amoenus
by its long antenna, stouter build and its habits when feeding.

176 W. MILNE ON THE

I believe this is the same animal as the one described by Mile.
Montet (9) as a variety of H. torquata, but left unnamed.
Habitat. — Draaifontein ravine pools. Abundant.

Genus PLEURETRA Bryce.
Pleuretra reticulata sp. no v.

PI. 13, figs. 18-18a.

Specific Characters. — Of small size, widest near the middle and
tapering to both extremities. No spines on anterior border of
trunk. Dorsally, four transverse rows of spines on trunk, also
one pre-anal and one anal. One row ventrally near front of
trunk and two spines farther back. Rostrum has very long^
setae, especially two laterally projecting ones. Antenna stout,,
about three-fourths of neck-width, with long setae. Teeth two.
Foot of four segments, narrow, with boss on first segment. Spurs
distinctive. Transverse ventral ridges nine or ten. Corona to
collar (minus flaps) 10 to 12 ; sulcus narrow with sharp peg-like
ligule. Upper lip rounded with a notch. Stippled. Size,.
l/120th inch.

After examining this species carefully in 1914, and on looking^
over some older notes, I found a set which I had completely
forgotten on this very animal. Thus I was furnished with a good
opportunity for comparison, all the more fortunate in that the
spined species are notoriously variable. Evidently this is a very
stable form, as the sketches are practically identical. It re-
sembles Macrotrachela aculeata in shape, and differs from the
other spined species in not having the clumsy rump. Its shape
is elegant in all positions, and the spurs, which are always seen
when it feeds, finish off the appearance well. It is beautifully
stippled over trunk, foot and spurs.

At times it creeps quite fast with a glide, and moves more
quickly than the other spined species.

The anterior border of the trunk has no spines. The trunk
has four dorsal cross rows, with eight spines each in the first,,
second and fourth rows, and nine in the third. There are four
spines on the pre-anal segment and four on the anal. Just above
the last two rows of spines there is, in each case, in the middle of
the segment, a double blunt short thorn. The ventral row consists.

BDELLOID ROTIFERA OF SOUTH AFRICA. 177

of six spines plus two large lateral ones, and is situated on the
first segment of the trunk and about the middle of it. The other
two ventral spines are near the sides and opposite the first dorsal
row. In one set of notes it is stated that the two front rows are
incipient, just as if the bends of the ridges had grown out to
points. The other rows are similar but more developed.

The rostrum is long with a fairly prominent double lamella.
The setae are long, and noticeable when feeding ; two from
the corners are long, and like those of the variety amoenus (p. 173).
The brushes of setae in the antenna are about as long as the
antenna itself. There are two plates alongside the antenna. The
dental bulb is rounded with a quadrate upper margin, and the
two teeth are not far from the middle. The transverse ventral
ridges have a wavy appearance, more especially the first. The
spurs are longer than the width of the ankle, divergent and
decurved, almost sickle-shaped.

Each wheel in the corona bears a seta, and these two setae
cross each other in every case. The ligule is always present and
is a very short peg-like structure. The upper lip rises just over
the sulcus bridge, and is broadly triangular with a rounded front
margin, slightly notched. There are two ear-like flaps from the
lower lip, quite abnormal in size.

The longitudinal ridges are wavy and help to give a reticulated
appearance to the animal. The skin is not hardened nor sug-
gestive of a lorica. Apparently there are only three toes. The
opening of the sheath from which the toes protrude is round and
very small. When resting against the cover-glass, only three toes
can be seen and they appear to fill up the whole opening. The
back one may bifurcate, but I could not trace any sign, as the
toes when planted on the glass are unfortunately always in the
shadow of the trunk, and being so small cannot be well seen. I
never could get a proper side view of them.

The egg is broadly ovate and symmetrical, with sixteen or
seventeen small swellings, giving it a wavy outline. The spines
and ridges are visible in the egg, before the hatching takes place.

I found one specimen in Aberdeenshire which agreed extremely
well in all particulars with the South African ones. It gave the
same suggestion of three toes.

Habitat. — Ground moss, Draaifontein and Springfield, Uiten-
hage. Fairly abundant.

178 • W. MILNE OX THE

Genus SCEPANOTROCHA Bryce.
Scepanotrocha galeata sp. no v.

PI. 13, figs. 17-17b.

Specific Characters. — Of very small size ; very slender. Creeps
fast with a glide. Narrow rostrum, with single spoon-shaped
lamella. Antenna stout, very short, about one-third of the very
narrow neck. Dental bulb small, rounded, with four or five
teeth. Trunk deeply plicate ; lumbar region long. Foot
moderately long, apparently of four joints. Spurs of moderate
length, divergent, without interspace. Upper lip a heavy mass,
broadest at upper margin. Size, l/130th inch.

This is another very small species, only likely to be noticed
when in a favourable position. The most noticeable feature is the
overgro\vn helmet-like upper lip, which is broadest at the upper
margin, the front being straight or a very flat curve. Round
and towards the front the upper lip is thick.

The wheels could never be clearly made out. The wheel-whirl
is all in front and in a vertical direction. Only a very indistinct
or hazy view of the wheels can be got through the flare of the
cilia, but they seemed to be very small, possibly about two-thirds
of the collar. Only from one view did I get the impression that
the wheels were in the usual position. The indications on the
whole were in favour of the wheels being at a very considerable
angle to the usual position.

Sometimes there was an appearance as if there were a thin
laminate part between the upper lip and the wheels. It is a
dapper little fellow, and feeds usually with the neck bent grace-
fully, and holding the head well up in a gallant way. When
creeping, the neck shows three gentle curves on each side.

Habitat. — Rock moss, Euphorbia Kloof, Uitenhage. Rare.

Genus MNIOBIA Brvce.

Mniobia animosa sp. no v.

PI. 12, fig. 13.

Specific Characters. — Of moderate size ; spindle-shaped. Ros-
trum fairly stout. Antenna broad, very short, about one-fourth
neck-width, with a prominence on each side of it. Front of
dental segment wide. Dental bulb small, with three large well-

BDELLOID ROTIFERA OF SOUTH AFRICA. 179

•separated teeth. Lumbar region fairly heavy. Contractile
vesicle fairly large. Spurs short. Foot short, of five segments.
"Corona equal to collar. Upper lip a triangle. Deeply stippled.
Size, l/80th inch.

This is a rather keen-looking, graceful animal when feeding,
^nd generally feeds with the foot extended. It is deeply stippled
from and including the dental segment down to the spurs. The
front of the dental segment is wider than the part in front of it.
The anal segment looks double. The foot is smooth, and short,
though it has so many segments. Spurs are not very sharp, but
are decurved so that they look usually very short and very blunt,
like those of Mniohia ohtusicornis. There is a swelling, longitudin-
ally, along the first foot segment, which is short. The corona is
i;o the collar as 8 to 8. The sulcus is equal to about one-third
of the disc width. The upper lip is flat, rising abruptly near the
middle into a triangle whose base is as wide as the sulcus.

Habitat. — Ground moss, Grahamstown.

Genus ADINETA Hudson.
Adineta cuneata sp. no v.
PI. 14, figs. 22-22a.

Specific Characters. — Of large size, stout, hyaline. No setae
<or expansions on the rostrum. Antenna fairly long. Teeth two.
Hump has no distinctive shape. Contractile vesicle large and
elongated. Foot stout, of five segments. Deep constriction at
Ankle when foot is fully extended. Spurs short and at right
angles to foot, with a large convex interspace. Toes stubby.
There are large foot glands. Size, l/75th inch.

Murray (7) was well acquainted with this animal and con-
csidered it a good species. It has a short hopping sort of motion,
reminding one of the hop of a rabbit, when it is feeding and
mioving about slowly.

The only species near this is A. vaga. A. cuneata has a less
iclegant shape, and a slightly squarer head. It has a stouter foot
.and a segment more in it, and a narrower constriction at the
iankle when extended, which gives a distinctive appearance to
th.e spur segment. The part posterior to the spurs is shorter and
the toBs more stumpy in appearance.

180 W. MILNE ON THE

The two are easily distinguished from each other, at a glance^
by the shape of the spur-segment and the spurs.

Habitat. — Moss ; very abundant all over Uitenhage district,,
and in other parts.

Macrotrachela quadricomifera var. nov. rigida
PL 14, figs. 23-23C.

Specific Characters. — Very large and strong ; trunk black-
brown in colour ; skin extremely thick. Rostrum stout and.
fairly long, with double lamella. Antenna long and stout, equal
to two-thirds neck width. Jaws very large ; teeth two large
and two small. Neck very stout. Trunk deeply plicate later-
ally. Rump very distinctive. Foot long and narrow. Spurs
excised below. Corona bold and large ; sulcus wide ; a short
seta on each wheel. Upper lip complicated. Deeply and.
beautifully stippled. Size up to l/40th inch.

This is the animal mentioned in Part I (10) as possibly a
variety of Philodina childi, and is very likely the same as the-
CalUdina quadricomifera of very large size seen by Murray (4)
in moss from India.

Since I wrote Part I, I have seen a few good specimens, found
in moss sent me by Mr. P. Smith, Umtata. In all these I made
a careful examination as to the nature of the back toe. The
animal frequently crawls against the cover-glass, but it take*
such long strides that one has usually to move the stage in
order to see the toes planted ; and as the foot is sometimes
thrown to the side, and sometimes directly under, it is almost-
hopeless to try to anticipate where the toes will appear. The
back toe has a double appearance, something like two blunt
cones, sliced longitudinally almost to the middle and placed
against each other. There was an appearance of muscles up-
each half, but there might have been up the middle also though
not seen. I thought there might prove to be an incipient toe
orifice at the end of each half, but was unable to detect any
signs of it. The toe appearance varies in different specimens^
but fig. 23c gives a fair average. When the toes are almost with-
drawn, the orifice shows more like Philodina than Macrotrachela ►

It is a quiet, slow animal, deliberate in all its motions, and
can be kept in a slide for a long time. The chances are that

BDELLOID ROTIFERA OF SOUTH AFRICA. 181

when the slide is examined at any time, it will be found either
feeding freely, or completely contracted into a ball — less seldom
will it be found creeping. It sometimes lies for so long a time-
contracted that one has difficulty in deciding whether it is alive
or not. I once put one aside as dead, and on again examining
the slide in which it was, for some other purpose, found it feed-
ing briskly.

Its shape varies very little on account of the extremely thick
skin. There is never a wrinkle in the trunk, only, when it sits,
back feeding, the trunk widens out, but the shape is perfects
It has a habit when feeding of pushing forward the first trunk
segment towards the antenna, till it stands out like a frill.

The rump is the most distinctive part. It is not particularly^
heavy, and rises up — fairly flat across — for a considerable dis-
tance backwards, then dips sharply down forming an elbow
ridge, which is practically rigid owing to the stiffened material
bounding it. I have never seen the ridge obliterated, even
when the foot is fully extended. Fig. 236 gives a side view.

The corona is large and graceful, and the wide sulcus equal
to three-fourths of the wheel-width. Corona, collar and neck
are to each other as 37, 22 and 18. There is a comb-like ridge
which runs across the wheel, and extends well into the sulcus
with a bold curve. The central part of the upper lip front
margin (fig. 23a) is copied from the few samples lately seen,
and is rounded ; but in all the large number of specimens ex-
amined formerly, the central part is distinctly triangular with
a sharp apex. The Grahamstown examples were rather smaller
in size than the Umtata ones.

The dental bulb is extremely large — about 1 /500th inch —
and is surrounded by a heavy muscular mass. Two teeth are
very broad, and two, one on each side of these, are smaller,
about one-fourth the size of the others, but occasionally one of
these is wanting or scarcely noticeable. There is a large granular
gland behind the bulb.

The intestine is large and heart-shaped, and very thick
walled. There is a distinct, narrow, button-like muscular cinc-
ture between the intestine and the stomach (fig. 23).

The spurs, on the first segment of the foot, are blunt and
flat, and lie near each other.

The stippling is of the same nature as that of Philodina grandis^

:182 W. MILNE ON THE

(10). The stipples are larger, but are arranged in the same
manner, and have the same beautiful honeycomb appearance.

Habitat. — Tree and rock moss, Grahamstown and Umtata.
Fairly numerous.

A good many other species of Bdelloida were examined suffi-
ciently to see that they were different from any that have been
hitherto described, but owing to some detail or other being
absent from my notes I have not attempted to describe them.
There was one dainty, pert little Macro trachela, with a very
distinctive antenna equal in length to three times the neck
width, motile, and with a rhythmic beat in unison with the
motion of the jaws ; found on weeds in running water.

I intended giving a list of all the Bdelloida I observed in South
Africa, but find it impossible to do so at present. This list may
appear as an Appendix to the above on some future occasion.

Bibliography.

1. Janson, 0. : Versuch einer Uebersicht liber die Rotatorien-

Familie der Philodinaeen. Bremen, 1893.

2. Murray, J. : On a New Family and Twelve New Species

of Rotifera of the Order Bdelloida, etc., Trans. Roy.
Soc. Edin., vol. xli. 1905.

3. Murray, J. : The Rotifera of the Scottish Lochs, Trans.

Boy. Soc. Edin., vol. xlv. 1906.

4. Murray, J. : Some Rotifera of the Sikkim Himalaya, Journ.

Boy. Micr. Soc. 1906.

5. Bryce, D. : On a New Classification of the Bdelloid Roti-

fera, Journ. Quchett Micr. Club, Ser. 2, vol. xi. 1910.

6. Murray, J. : Bdelloid Rotifera of South Africa, Ann. Trans-

vaal Mus., Pretoria, vol. iii. 1911.

7. Murray, J. : Some African Rotifers, Journ. Boy. Micr.

Soc. 1911.

8. Bryce, D. : On Five New Species of Bdelloid Rotifera,

Journ. Quekeit Micr. Club, vol. xii. 1913.

9. MoNTET, G. : Contribution a I'etude des Rotateurs du

bassin du Leman, Bevue Suisse de Zoolorjie, vol. xxiii,
No. 7. 1915.
10. Milne, AV. : On the Bdelloid Rotifera of South Africa,
Part I., Journ. Quekett Micr. Club, Ser. 2, vol. xiii. 1916.

bdelloid rotifera of south africa. 183-

Description of Plates.

Plate 10.

Fig. 1. Macrotrachela verecunda, dorsal, creeping,
la. Macrotrachela verecunda, corona.
16. Macrotrachela verecunda, antenna.

Ic. Macrotrachela verecunda, top of corona with view oi'
upper lip.

2. Macrotrachela smithi, dorsal, creeping.
2a. Macrotrachela smithi, corona.

3. Macrotrachela timida, dorsal, creeping.
3a. Macrotrachela timida, corona.

4. Macrotrachela timida, var. inquies, foot and rump.

5. Macrotrachela faveolata, dorsal, feeding.
5a. Macrotrachela faveolata, jaw.
56. Macrotrachela faveolata, spurs.
5c. Macrotrachela faveolata, side view, large wart.
bd. Macrotrachela faveolata, front view, large wart.

Plate 11.

Fig. 6. Hahrotrocha placida, dorsal, feeding.

6a. Hahrotrocha placida, dorsal, creeping.

66. Hahrotrocha placida, top of corona with upper lip,

6c. Hahrotrocha placida, corona, beginning to unfold.

7. Hahrotrocha plana, dorsal, feeding.

8. Hahrotrocha iners, dorsal, feeding.
8a. Hahrotrocha iners, dorsal, creeping.

,, 86. ^a6ro^rocAa wers, corona, ventral, showing large spout-
like lower lip.

,, 8c. Hahrotrocha iners, spurs and toe segment as seen ixt>
adult against cover-glass.

,, 9. Hahrotrocha elusa, dorsal, creeping.

,, 9a. Hahrotrocha elusa, dorsal, feeding.

?>

5>
> J

Plate 12.

Fig. 10. Hahrotrocha elusa, var. vegeta, dorsal, feeding.
,, 11. Hahrotrocha tranquilla, dorsal, feeding.
11a. Hahrotrocha tranquilla, dorsal, creeping.
12. Hahrotrocha pertinax, dorsal, creeping.
12a. Hahrotrocha pertinax, corona, dorsal.

55
55

184 W. MILNE OX THE BDELLOID ROTIFERA OF SOUTH AFRICA

Fig. 13. Mniohia animosa, dorsal, feeding.
14. Hahrotrocha alacris, dorsal, creeping.
14a. Hahrotrocha alacris, corona.

Plate 13.

Fig. 15. Hahrotrocha gulosa, dorsal, feeding.
15a. Hahrotrocha gulosa, dorsal, creeping.
156. Hahrotrocha gulosa, side view, upper lip.

16. Hahrotrocha valida, dorsal, feeding.
16a. Hahrotrocha valida, dorsal, creeping.

17. Scej)anotrocha galeata, dorsal, creeping.
17a. Scepanotrocha galeata, corona, dorsal.
176. Scepanotrocha galeata, corona, ventral.

18. Pleuretra reticulata, dorsal, creeping.
18a. Pleuretra reticulata, corona, dorsal.

Plate 14.

Fig. 19. Otostephanos regalis, dorsal, creeping.
,, 19a. Otostephanos regalis, dorsal, feeding ; stippling rather

exaggerated.
,, 196. Otostephanos regalis, corona, ventral.
,, 20. Otostephanos torquatus (Bryce) var. amoenus, dorsal,

creeping.
„ 20a. Otostephanos torquatus (Bryce) var. amoenus, corona,
dorsal.

21. Otostephanos monteti, dorsal, creeping.
21a. Otostephanos monteti} corona, dorsal.

22. Adineta cuneata, head, dorsal.
22a. Adineta cuneata, foot, posterior with spurs.

23. Macrotrachela quadricornifera, var. rigida, dorsal, creep-
ing.

23a. Macrotrachela quadricornifera, var. rigida, upper lip.
236. Macrotrachela quadricornifera, var. rigida, rump, side

view.
23c. Macrotrachela quadricornifera, var. rigida, back toe.

i»

II

Where proportional numbers are given in the text, each unit
represents 1 /6000th inch.

Joum. Quekell Microscopical Club, Ser. 2, Vol. ZIII., No. 79, November 1916.

JOURN. Q. M. C.

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185

NOTICES OF BOOKS.

The Microscopy of Vegetable Foods, with Special Kefer-
ENCE TO the Detection of Adulteration and the
Diagnosis of Mixtures. By Andrew L. Winton, Ph.D.,
with the collaboration of Dr. Josef Moeller and Kate B.
Winton, Ph.D. xiv + 702 pages. 9J x 6| inches. 635 text
figures. (New York : John Wiley & Sons. [London : Chap-
man & Hall.] 1916. Price £1 75. 6d. net.)

This valuable contribution to applied analytical science has
for its purpose the identification of food products of vegetable
origin, by the microscopic structure and microchemical reactions
of their tissues and cell-contents. As the subject matter is
essentially a department of applied botany, the study and prac-
tice of it cannot be properly taken up until after a course of
instruction in vegetable histology or the microscopic anatomy
of phanerogamic plants. The practical study of food micro-
scopy should commence with a systematic study of the most
important seeds, fruits, leaves, flowers, roots and barks used as
foods, or food adulterants. This work should include : the
macroscopic anatomy; the histology of transverse (less often
longitudinal and tangential) sections ; the histology as studied
in surface preparations of the successive layers obtained by
scraping or stripping, and the microscopic character of the
powdered, pulped or macerated material. The surface pre-
parations provide the details of cell-structure most useful in
practical work, while the examination of the powdered material
■supplies the characters of isolated cell-elements which are im-
portant in diagnosis. Although the work of _^ microscopic ex-
amination is distinctly botanical, in many cases a satisfactory
idea of a material can only be obtained by combining the micro-
scopic with a chemical analysis.

The preparation of materials for examination, the principal
histological elements and the morphology of organs are all
■dealt with in the first part of the book. The following parts

186 NOTICES OF BOOKS.

are devoted to the special articles which are grouped together
under such headings as Grain, Oil Seeds, Legumes, Nuts, Veget-
ables, Spices and so on. This grouping may have some practical
utility, but it strikes one as unscientific and leads to the con-
stant use of a fairly full index. Each special article is divided
into : general and macroscopic details, histology, diagnosis and
bibliography. The histology is illustrated by over 600 figures in
the text giving the transverse section, surface view of the cell-
elements and other minute details which mav enable the analv-
tical histologist to name the seeds, roots, barks or other vege-
table products, from which the material under examination
was prepared. Although several of the special articles deal
with vegetable products rarely found on the English market,
the major part of the book cannot fail to be of very great service
to the microscopic analyst in this country. In addition to the-
special bibliographies already referred to, there is a general
bibliography and a glossary of technical terms. The labour
necessary for the production of such a book must have been
very great indeed, and the result reflects great credit on the
authors.

The Pkactical Principles of Plain Photomicrography. By
George West, xiv +146 pages, 8 plates, 5 text figures,
10 X 7J inches. (George West. Price 45. 6(/. net.)

The author of this excellent book rightly insists that the
beginner should commence with low powers and as he gains
experience proceed step by step to the use of the higher powers.
The book is not overloaded with detail, but well-chosen adapta-
tions are fully described only when they are found suitable
for the end in view. One chapter deals with the use of a land-
scape camera for taking photomicrographs. More importavjt
is the description of the method adopted by the author for
dispensing with the camera altogether. Here the author places
the source of light with the microscope in a light-proof chamber
through a hole in the wall of which the tube of the instrument
projects. The plate is placed on an easel in another chamber,
the dark room, where the exposure is made and the plate deve-
loped. The photographic apparatus is of the simplest form, no
camera or dark-slide being used. The practical microscopist could

NOTICES OF BOOKS. 187

not wish for a more accurate or easy method of obtaining reli-
able photomicrographs than those described by the author in
Part VII, who declares that by this method he has obtained his
best results. Certainly the plates 3-8 which reproduce some of
the author's work demonstrate the beauty of the results. There
is a table giving complete details regarding the taking of the
negatives for these illustrations. There is also included a chapter
on special methods of illumination, a list of photographic neces-
saries and a number of formulae for solutions, etc. Altogether
the book may be cordially recommended to the practical worker
with the microscope, and even the experienced worker in photo-
micrography may find very useful hints for his guidance.

Aids to Bacteriology. By C. G. Moor, M.A., and William
Partridge, viii -f- 278 pages. 6| x 4 inches. Third edi-
tion. (Bailliere, Tindall & Cox, London. 1916. Price,
cloth, 3^. 6d. net ; paper, 3*. net.)

This well-known vade-mecum of the bacteriologist has now
reached its third edition and nearly all parts of the book have
been revised and enlarged. The amount of information con-
tained in the compass of this small book is quite extraordinary,
covering as it does the whole range of bacteriology, using that
term in its widest sense. After an introductory chapter dealing
with the classification and biology of the bacteria, we have three
chapters dealing respectively with bacteriological apparatus, the
preparation and use of nutrient media and the microscopic
examination of bacteria. All the principal pathogenic bacteria
are dealt with in chapters V-XIII, and these are followed by
chapters dealing with the blastomycetes (yeasts), hyphomycetes
(moulds), and the principal pathogenic protozoa. The wide
scope of the book is indicated by the inclusion of chapters deal-
ing with the special bacteriology of water, milk and other foods,
air, soil and sewage, and the bacterial diseases of plants. A full
index is provided.

We may congratulate the authors on the success they have
achieved in compiling this useful and comprehensive little book.

JouRN. Q. M. C, Series II.— No. 79. 14-

188

PROCEEDINGS

OF THE

QUEKETT MICROSCOPICAL CLUB.

At the 515th Ordinary Meeting of the Club, held on March 28th,
1916, the Vice-President, D. J. Scourfield, F.Z.S., F.R.M.S., in
the chair, the minutes of the meeting held on February 22nd
were read and confirmed.

Messrs. Reginald H. S. Bevington, Henry Clarke Terry, Her-
bert H. Smith, Alfred Hardcastle, David Gillies, Reginald W.
Thomas, Georges Rasquin and John Tennant, M.A., were
balloted for and duly elected members of the Club.

It was announced that the son of the late Mr. Dunstall had
very generously placed at the disposal of the Club his father's
collection of slides of Diatoms, Insects and Botanical specimens,
for the curator to select any objects not already in our Cabinet.
The collection contains many useful additions, and the best
thanks of the Club are due to Mr. Dunstall for the donation in
memory of his father, who was such an enthusiastic member of
our Club.

The following additions were made to the Library :

Ray Soc. : British Marine Annelids, vol. iii., part ii., plates,
W. C. Mcintosh ; Principles of Plant Teratology, vol. i.,
W. C. Worsdell ; British Freshwater Rhizopoda and
Heliozoa, G. H. Wailes, vol. iii. Presented by Henry
Morland : Index to the Localities named in Plates
1-288 of Schmidt's Atlas der Diatomaceen-hande.
Presented by Alpheus Smith: Q. M. C. Register; Ele-
ments of Entomology, W. S. Dallas.

Mr. W. Milne, M.A., B.Sc, F.R.S.E., gave a paper, " On the
Bdelloid Rotifera of South Africa," Part I. Mr. Milne said the
material for the paper had been gathered intermittently during
the last ten years. A few of the species described were aquatic,
but the large majority were moss-dwellers. The aquatic species

PROCEEDINGS OF THE QUEKETT MICROSCOPICAL CLUB. 189

•■are probably very numerous in South Africa, but little attention
liad been paid to them. Only a few meagre lists of South
African Bdelloida, with no description of new species, had been
published when in 1911 Murray's Bdelloid Rotifera of South
Africa was issued. In it he mentioned fifty-three species as
liaving been found, forty of which he had himself seen. Of these
"forty Mr. Milne had seen all but seven, and of the other thirteen
lie had seen ten. He had been enabled to widen the scope of
his investigations by the help of several friends, who provided
moss from various localities, and some of the species were named
after them. Mr. Milne had corresponded with Mr. Bryce, and
Tiad received assistance and helpful suggestions from him, and
also from Mr. James Murray. Mr. Bryce had done a great
■service to students of Bdelloida in publishing his new classifica-
tion. He had brought order out of what was fast becoming
•chaos and his classification was excellent.

Mr. Milne's paper (Part I) treats of one new family, two
new genera, fourteen new species, and two new varieties of
South African Rotifera. In addition to the systematic defini-
tion, details of structure, habitats, mode of life, feeding, method
of swimming and crawling, and even their capacity for enduring
captivity are fully described. It was impossible to give all this
during one evening ; but Mr. Milne had prepared lantern slides
from the drawings illustrating the paper, and with their assis-
tance alluded to some of the most interesting points of a number
of species.

The Chairman expressed great appreciation of the paper,
with its description of such a large number of new species. He
invited discussion, and himself inquired whether Mr. Milne had
come across any males among the rotifers of South Africa.

Mr. David Bryce regretted the absence of Mr. Rousselet, who
would have enjoyed the paper. He said all would look forward
to the second part, containing the remainder of the species.
He was pleased to see Mr. Milne proposed to make a new family
for Monoceros, which was quite necessary. It was interesting
to know this species had been found in England — he had found
it in the river Lydd, and the late Mr. Dunstall had found it at
Xynton. He was sure we should all be pleased to have the
paper in the Journal.

Mr. Milne, in answer to the chairman, said he had not come

190 ' PROCEEDINGS OF THE

across any male rotifers in South Africa. He expressed his
gratitude to Mr. Bryce for the assistance he had given, and his
admiration for the system of classification he had originated*
At the suggestion of the chairman, a very hearty vote of thanks
was accorded by acclamation to Mr. Milne for his lecture. The
chairman also proposed a vote of thanks to Mr. Biss, of the
Photomicrographic Society, who had come at very short notice,
and notwithstanding the terrible weather, to take charge of
the lantern in the unavoidable absence of their own member
who usually undertook that duty. This motion was heartily
endorsed.

At the 516th Ordinary Meeting of the Club, held on April 25th,.
1916, the President, Arthur Dendy, D.Sc, F.R.S., in the chair,
the minutes of the meeting held on March 28th were read and
confirmed.

Messrs. Emile Topsent, Arthur W. Aldis and Rev. W. Francis
Deey, M.A., were balloted for and duly elected members of the
Club.

The President said the members would be sorry to hear he
had just received the news of the death of Mr. C. Lees Curties,
which occurred on April 24th. He and his father before him
had built up a unique business, and 244 High Holborn was
regarded by many as a rendezvous where one was sure to meet
some kindred spirit and to hear the latest scientific news. Mr.
C. L. Curties greatly extended the business by the establish-
ment of a factory where microscope stands are made, and of an
optical department for the construction of object glasses. He
had a thorough knowledge of the microscope, as well as a wide
and varied acquaintance with all sorts of scientific instruments.
He was always ready to place his expert knowledge at the
disposal of anyone who asked his advice. There can be little
doubt that his death was hastened by the heavy strain due to
extra work on account of the war, and to his persistent refusal
to give himself a much-needed holiday. Mr. Curties had been
a most useful member, always willing to give assistance to the
Club in every way, and his kindness and courtesy were known
to all. He was elected a member in June 1880 and F.R.M.S. in
1894. A formal motion of regret and condolence with the
relatives was passed.

QUEKETT MICKOSCOPICAL CLUB. 191

The list of Donations to the Library included four books
from the late Librarian, Mr. Alpheus Smith — for which the
■cordial thanks of the Club were returned.

Mr. Chapman Jones read a short paper on " The Secondaries
or Dotted Structure in the Pinnulariae." This explained and
described a series of photographs which he exhibited. He said
that about forty-five years ago Mr. H. J. Slack contributed
a, note to the Royal Microscopical Society, in which he remarks
that at one time it was supposed that the Pinnulariae were dis-
tinguished from allied forms by solid costae replacing beaded
"bands, but subsequently this distinction was not considered
valid. That an examination of the Pinnulariae on Moller's
type-slide led to the belief that instead of broad, irresolvable
ribs, a truer view of the costae showed fine lines of beads spring-
ing from the median band, with a furrow between them, and in
that farrow another line of beads at a lower level.

In a discussion which followed, Mr. O'Donohoe said he was
glad Mr. Chapman Jones had brought the subject before them.
When he had done so it was considered by a few members that
the structure had no real existence, but Mr. Chapman Jones
had quite confirmed his ideas on the matter.

There were seven photos exhibited, taken with a 2-mm. Holos
objective, N.A. 1*36, x 8 compensating eyepiece, and a Holos
immersion condenser. In some the effects of a solid central
cone of light were shown, while others were taken with oblique
light and a green screen. The magnification was from x 1,200
to X 1,300. In all of them the dots were visible and bore out
the author's contention that they occurred on a membrane,
which, under normal conditions, would form part of the struc-
ture of the diatom-valve as usually seen. The chairman ex-
pressed the gratitude of the meeting to the lecturer for his
interesting exhibit and the paper explaining it.

The Hon. Secretary then read a paper by Mr. A. A. C. Eliot
Merlin, F.R.M.S., on " Nitzschia singalensis as a Test Object
for the Highest Powers." Mr. Merlin had received from Mr.
E. M. Nelson a styrax mount of N. singalensis from Amherst
in Burma. Its minute structure is similar to that of other
varieties of the genus, but is extremely fine. The transverse
striae had been seen by Mr. Nelson, but most other micro-
scopists had failed to make them out. Mr. Merlin thought that

192 PROCEEDINGS OF THE

Amphipleura pellucida was no longer a sufficient test for objec-
tives of the highest power : for many years any tolerable oil-
immersion of moderate aperture could easily reveal its once;
elusive transverse striae by oblique light. Really good objec-
tives of rS N.A. will reveal them with axial illumination. Of
course, to show the dotted structure is a more difficult task..
" With Nitzschia singalensis the case is different, and any micro-
scopist who can clearly reveal the transverse striation may^
feel satisfied with his optical appliances." A very beautiful
photograph at 3,600 diameters taken with a l/8th apochromat-
of 1'42 N.A., by means of oblique sunlight from a heliostat,,
accompanied the paper. This not only showed distinctly the
transverse striae, but was a most artistic production, and wa&
greatly admired when passed round for the inspection of the
members.

In response to the President's request for a discussion on th&
subject, Mr. Ainslie said he quite agreed with Mr. Merlin that
A. pellucida as a test leaves something to be desired, and that
its resolution is no great feat at the present day. But as a-
result of his experience he thought that until we have Nitzschia.
mounted in realgar the resolution of the transverse striae of
Amphipleura with a full solid axial cone of illumination remains
the best test of the all-round capacities of an oil-immersion
objective. He considered that there is no doubt that Mr. Merlin
possessed unusually keen eye-sight, and thought that most micro-
scopists need not be surprised nor disappointed if they fail to-
see the striae of Nitzschia except under the most favourable
conditions of illumination and manipulation. Mr. Ainslie had
a microscope on the table, with a Leitz 1/lOth oil-immersion of
1'33 N.A., with which he was easily able to show the striae of
Nitzschia. He said not only was this interesting in connection
with Mr. Merlin's valuable paper, but also it served as an example
of the occasional utility of a device for the enhancement of
resolution by the introduction of an analysing Nicol prism into
the path of the rays. He found that a very small illuminant
was also an advantage.

The President said they were all much indebted to Mr. Ainslie
for his remarks on the paper, and the thanks of the meeting
were voted to the author.

The President invited Vice-President David Bryce to take

QUEKETT MICROSCOPICAL CLUB. 193

the chair, and proceeded to give a short address on the spicular
structure of a sponge, Geodia japonica, of which he exhibited a
dried specimen. His description was illustrated with sketches
on the blackboard of the various forms of spicules, with a tabular
list of their names. He said that on a former occasion he had
brought before the meeting a very different example. He
had then purposely chosen a very simple sponge — Dercitopsis ;
in the present case a much more advanced condition of the
skeleton was found. The general structure of the skeleton
in the genus Geodia is figured in Bowerbank's Monograph of the
British Spongiadae. Typical specimens of Geodia japonica are
cup-shaped ; but they are often irregular in form, and in the
specimen shown the cup-shape is not fully realised. It was
not intended to give a description of the soft tissues, which it
would be impossible to investigate satisfactorily in the dried
specimen. There are the usual inhalent pores and exhalent
oscula, but in this species these are covered over, and are not
conspicuous. In Dercitopsis there is no striking differentiation
into what used to be called skeleton and flesh spicules, now
known as megascleres and microscleres ; but in all the higher
members of the Tetraxonid sponges the difference is very marked.
The skeleton spicules are large, and of them the skeleton is
built up, while the flesh spicules are small, often very minute,
requiring high powers of the microscope to resolve them satis-
factorily. It is a curious thing that they are usually scattered
between the skeleton spicules, and seem to serve no important
purpose in the economy of the sponge. The types of spicules
do not differ much in the various species of Geodia. In G.
japonica, amongst the megascleres we have first a form belonging
to the triaene series, the orthotriaene ; this has one ray very
much elongated and three much shorter ones. The short rays
lie more or less at right angles to the long ones ; hence the name.
The second type is the anatriaene, in which the three short
rays curve backwards, making a grapnel form. The third type
is very frequent, and is called the oxeote, and consists of a long
shaft sharply pointed at each end ; it is sometimes as much
as 2 mm. long. The fourth kind of megasclere is a small oxeote.
Amongst the microscleres the first type is known as the oxyaster ;
it is a star with a variable number of rays, often five or six.
These are sharp-pointed and rather long : they are supposed

194 PROCEEDINGS OF THE

to be derived from the primitive tetract form by an increase in
the number of rays. The second type of microsclere is a very
small aster, with short, blunt rays, known as a pycnaster. The
third type is the curious form called the Geodia ball, or sterraster.
It is a curious spicule, consisting of an oval body, of larger size
than either of the others, and practically solid. It has a de-
pression on one side, supposed to mark the position of the
nucleus of the mother cell. Prof. Sollas has figured the Geodia
ball with a nucleus. It consists, like other siliceous spicules, of
hydrated silica or opal. The surface is covered with small
projections. If you take a section of a Geodia ball — an optical
section can easily be focused — you find it is composed of
enormous numbers of slender rods, radiating from the centre,
and each one terminating in one of the surface projections. The
development shows it to be a true aster. It starts as an ordinary
aster ; as it enlarges it becomes a form with slender hair-like
rays, radiating from the centre ; as they increase they thicken
till they meet one another, and finally a further deposit of silica
gives rise to the marks on the surface. The arrangement of the
spicules is as follows : Taking the megascleres first, we find
that if you look at ^ cut surface of the sponge, you notice to-
wards the outside a definite radial arrangement ; towards the
inside this is confused. The radial arrangement is due to bundles
of megascleres, which run towards the surface. The heads of
the orthotriaenes are extended beneath the cortex, whilst the
shafts run inwards for a long distance. Associated with these
are found the anatriaenes. The larger oxeote spicules tend to
form very loose bundles, but towards the interior they lose
this arrangement. The whole sponge is covered with a white
incrustation about l/3rd mm. thick ; this is composed entirely
of the Geodia balls. Here we have a case where certain of
the microscleres have a definite function, forming a protective
armour on the outside. The minute pycnasters are on the
extreme outer surface. The oxyasters are scattered throughout
the ground substance, between the main spicules of the skeleton.
It can be seen that there are canals ramifying through the body
of the sponge, but the minute structure of the canal system
cannot be determined from the dried specimen. This sponge
belongs to the Astrotetraxonida, as shown by the astrose charac-
ter of its microscleres.

QUEKETT MICROSCOPICAL CLUB. 195

The President had brought a number of carefully cut portions
of the sponge for distribution amongst the members ; the natural
-position and arrangement of the spicules could be studied by
•cutting sections of the specimen. For examination of the indi-
vidual spicules boiling with a 10% solution of hydrochloric or
nitric acid and washing are required, the spicules being finally
mounted in Canada balsam.

Vice-President Bryce expressed the thanks of the meeting
-to the President for his valuable and interesting address, and
-for his kindness in providing the material, which would be
•studied by the members with much pleasure. His remarks
-were heartily endorsed by all present.

At the 517th Ordinary Meeting of the Club, held on May 23rd,
1916, the President, Arthur Dendy, D.Sc, F.R.S., in the chair,
-the minutes of the meeting held on April 25th were read and
'Confirmed.

Messrs. Cyril F. Hill, F.E.M.S., John Eudd Leeson, M.D.,
Alfred George, Edmund A. Robins, and Alfred McEw^en w^ere
balloted for and dulv elected members of the Club.

Mr. J. E. Barnard delivered a lecture on "X-ray Research
into Organic Structure as Exemplified by the Foraminifera."
As an introduction to this and as an illustration of the capa-
bilities of Mr. Barnard's method, Mr. E. Heron-Allen, F.L.S. etc.,
President of the Royal Microscopical Society, projected on the
screen an interesting series of lantern slides of Foraminifera.
He remarked that Mr. Barnard had obtained results which to
him seemed most remarkable, and of the deepest significance.

Until Mr. Barnard had applied X-rays to the production of
skiagrams of microscopic objects, the only method a.vailable for
studying the internal structure of the opaque foraminiferal
tests was by the laborious and often unsuccessful method of
rubbing them down into thin sections on a hone, and after
mounting them in Canada balsam examining them by trans-
mitted light. This, though satisfactory in many cases, was
hardly practicable where one specimen only was available, as
the risk of accidental destruction, especially in the later stages
of this process, was very great. Among the arenaceous forms,
•svhere the test is built up of sand grains more or less firmly

196 PROCEEDINGS OF THE

held together by a kind of cement, the difficulty of avoiding."
injury in an attempt at rubbing them down is very great, while--
not a few cases occur where, though the shell is calcareous, it has.
embedded in its substance particles of sand of varying size and.
hardness. These examples were dealt with by Mr. Barnard's
process with a success which could be obtained by no other-
means, and numerous examples were thrown on the screen where,
the internal structure was admirably displayed, of course
without any chance of disturbance having taken place, as the
tests had not been interfered with mechanically in any way^
In Astrorhiza arenaria the branching tubular body-cavity w^as^-
perfectly sho^vn in spite of the incrustation of sand on the ex-
terior. Cyclammina cancellata gave a view of the labyrinthine-
wall-structure which could not otherwise have been obtained,,
quite free from any suspicion of alteration, and absolutely
without injury to the original specimen. Orhiculina adunca^
which is normally opaque, revealed its spirally wound coil of
chambers in the most perfect manner, notwithstanding the-
difficulty of the varying thickness of the shell in different parts^
Fossil forms even, such as Nummulites, were successfully dealt
with, and a quite remarkable amount of structure was shown
as still existing capable of demonstration.

Mr. J. E. Barnard said :

" Some previous work on the application of X-rays to the--
study of microscopic objects had been reported upon in the
Compter Rendus, but the methods adopted did not seem to pro-
mise very satisfactory results. As an outcome of the fine^
work of Laue, Friedrich and Knipping the molecular structure
of crystals was exactly demonstrated, and it was shown also that
X-rays were a form of light differing only in wave-length from
the Herzian rays or those of other parts of the spectrum. This
work was followed up by Bragg in this country and it con-
stitutes one of the greatest advances in physical science that
has been made in recent years. The important fact that X-rays
could be reflected from a crystal surface was one of the results
arising from these experiments.

" We are confronted with the fact that for the last thirty
years, with one exception, there has been little actual advance
in microscopic optics. We know, too, that theory and practice
are almost in agreement : that the optician has been able to*

QUEKETT MICROSCOPICAL CLUB. 19T

produce lenses so nearly perfect that they almost reach the
theoretical limit. The only method by which any substantial
increase in numerical aperture, and consequent resolution, has
been obtained is by the use of ultra-violet light. By this means
resolution has been increased beyond the utmost that can be
obtained in any other manner. When reading the records of
the work done on X-rays, I was impressed with the idea that if
we could in any way use these rays as a source of energy for
microscopic work it would take us a great deal farther. Assum-
ing that some means of utilising them to the full is found, it
should be possible to demonstrate structure and to obtain resolu-
tion that is inconceivable by any method at present available
The slides Mr. Heron-Allen has kindly exhibited were the out-
come of some experiments to determine how far one might be
able to go in obtaining direct radiographs of microscopic objects,
enlargements being obtained by photographic means. The
method adopted for producing the radiographs is quite simple.
The tube used is provided with a lithium glass window, so that-
the soft X-rays are freely transmitted. Ordinary glass ob-
structs these very seriously. The tube is enclosed in a lead-
covered box, so that the rays cannot pass out except in the
desired direction. There are two or more lead diaphragms
fixed in a tube placed above the lithium glass window, each
diaphragm having a small central hole. By this means an
approximately parallel beam of X-rays of very small cross-
section is transmitted. The object is placed in the path of this
beam, which passing through it impinges on a photographic
plate placed in actual contact with the object. The resulting
radiograph is of course the same size as the microscopic object ^
(unmagnified), and the enlargement to lantern-slide dimensions,,
or whatever magnification may be desired, is obtained by
ordinary photomicrography. One of the difficulties encountered,
was the necessity of obtaining plates with a sufficiently fine^
grain to record the extremely minute details and to allow of
effective enlargement. But that this and other problems had.
been successfully overcome was apparent from the beautiful
series of lantern photographs that had already been exhibited."
The lecture was followed by an interesting discussion in which,
the President and Messrs. Hilton, Ainslie and Blood took part,,
and by a hearty vote of thanks which showed the appreciation.

198 PROCEEDINGS OF THE

by the members of a most interesting and valuable demonstra-
tion and lecture.

At the 518th Ordinary Meeting of the Club, held on June 27th,
1916, Vice-President D. J. Scourfield, F.Z.S., F.R.M.S., in the
<jhair, the minutes of the meeting held on May 23rd were read
and confirmed.

Messrs. Henry Wood and Ernest A. Maitland were balloted
for and duly elected members of the Club.

The Chairman said he had a very painful announcement to
make. Since the last meeting one of their oldest members, Mr.
R. T. Lewis, F.R.M.S., died on June 10th, aged seventy-seven.
He joined the Club in April 1866, within a year of its founda-
tion. He was elected honorary reporter in the autumn of that
year, and had most ably carried out the duties of the office ever
since. His attendance was probably a record. At the 500th
meeting he was able to say that he had been absent from his
post on only eighteen meetings during the period, and almost
all of these omissions had been caused recently by a severe ill-
ness. In the earlier days of the Club he frequently read papers,
chiefly on entomological subjects. These may be found in the
older volumes of the Journal, often beautifully illustrated by his
skilful pencil. His presence was one of the most familiar to
the members. He was at the meeting in April, but was unable
to come to that in May, and passed away after about a month's
illness.

They had also lost one of their honorary members. Mr. F.
Enock died on May 26th, aged seventy-one. Mr. Enock was well
known for his studies in entomology. Some years ago he had
frequently attended their meetings and given occasional ad-
dresses on his favourite subject, but he had not been able to
be with them in recent years. The members assented to the
Chairman's motion that letters of sympathy and condolence be
sent to the relatives.

The Hon. Secretary informed the meeting that he had re-
ceived from Mrs. Priest, the widow of a former member, a
cabinet of micro-slides for addition to the Club's collection. Mr.
Priest was well known for his studies in sponges, and desired
before his death that the Club should be presented with a num-

QUEKETT MICROSCOPICAL CLUB. 199*

ber of his specimens. The Committee had accepted this very
kind gift, and had directed that a letter of thanks be sent ta
Mrs. Priest. He thought that the members would like to endorse-
the action of their committee. This proposal was heartily
assented to by those present.

Mr. W. Traviss exhibited and described an apparatus which
he thought would be useful in pond collecting. It consisted of
a hollow rod, about the length of an ordinary walking-stick, to
one end of which was attached a triangular scraper. This also
was hollow, and in communication with the interior of the rod.
The top of the rod being closed by a finger, and the scraper being-
drawn over brickwork, wood, and similar objects under water^
on removing the finger the water would rush into the tube
carrying with it any organisms that had been removed by the-
scraper, they could be then transferred to the collecting-bottle^
The action of the apparatus was similar to that of a dipping-
tube on a large scale. The Chairman considered that the
instrument would prove useful for the purpose for which it was
intended, and proposed a vote of thanks to Mr. Traviss for
bringing it before them, which was accorded.

The Chairman, introducing a paper by Mr. H. Wallis Kew^
entitled " An Historical Account of the Pseudo-Scorpion Fauna
of the British Isles," said Mr. Wallis Kew was a well-known
authority on these creatures, which were unfortunately not
much studied. The paper was a valuable one, and though
there was not time to read it on this occasion it would appear-
in full in the Journal. Thanks were accorded to Mr. Wallis^
Kew for his communication.

Mr. A. E. Hilton then read a paper on " The Sporangia!
Characters of Mycetozoa and the Factors which influence them."
He said : It is, perhaps, not sufficiently realised that in the
small group of the Mycetozoa we have not only a convenient
microcosm of elementary biological phenomena, but also a clue^
to the solution of some of the problems which these phenomena
present. Applying to the Mycetozoa words used by an eminent
physiologist in a similar connection, it may be said of these
primitive organisms that they show with singular clearness how
" quite simple combinations of well-known forces lead to the^
performance of complicated and apparently purposeful results."^
In the light of this luminous principle, which is true of all living.

200 PROCEEDINGS OF THE QUEKETT MICROSCOPICAL CLUB.

things, we may consider some of the sporangial characters of

Mycetozoa.

" When we are asked what is the use of studying the Myce-
iozosL, our answer is, that, so far as we are able, it is our business,

as microscopists and nature students, to make each small thing

imfold its secret, and in so doing, perhaps, to unfold other and
•wider secrets."

The Chairman said : The formation of the sporangia of the
Mycetozoa presented many important problems, and it had the
■advantage of lending itself to experimental work. No doubt
.surface tension plays a large part in the process, but it seems
•almost impossible to believe that such structures can be due
mainly to that force. Of course the globular forms are the
^direct outcome of it, but the origin of the stalks, for instance,
must require other factors. The whole subject is very inter-
"Csting, and should repay much study and careful experiment.

Many of those present joined in a discussion on various points,
•and Mr. Hilton replied to some questions. Dr. Rudd Leeson
recommended the study of several books as likely to throw
light on the subject, especially one by Professor Bayliss, The
Princifles of General Physiology, and a very useful and inexpen-
•sive little work by Prof. B. Moore, The Origin and Nature of
Life. At the suggestion of the Chairman a hearty vote of
thanks was given to Mr. Hilton for his interesting paper.

201

OBITUARY NOTICES.
RICHARD THOMAS LEWIS, F.R.M.S.

March 2lst, ISS9— June 10th, 1916.

IRiCHARD Thomas Lewis was born at Knightsbridge in the parish
of St. Margaret's, Westminster, on March 21st, 1839. He lived
an the house where he was born until 1882 and was ever proud
of being a Westminster citizen. There never was a truer Lon-
doner. He often said he had rather have a garret in London
iihan a mansion out of it. In middle life he served his parish
::as a Commissioner of the Duchess of Somerset's Charity and as
^a member of Committee of the first Free Library opened in
Xondon.

His education was begun by his uncle, Henry Lewis, who
liad a school at Colchester. At this time his school-chum was
J. Archer Spurgeon, younger brother of the more famous Charles,
^ho left the school soon after Richard Lewis entered it. Later,
lie went to a boarding-school in Stratford-le-Bow, where he
•learned from its inventor, Mr. John Freeman, the system of
>^shorthand which he used with such success throughout life.
Mt. Freeman aroused his interest in astronomy.

Early holidays were often spent with his maternal grand-
father, Robert Mummery, at Dover. During these he learned
tiO know and love the flora of the Downs.

In 1853-4 he studied at University College School, then
under the direction of Prof. Key. On leaving school he entered
business with his father, George Cyrus Lewis, but his leisure
-was filled with studies to which he turned eagerly, after days of
what was to him mere drudgery.

He attended Tyndall's lectures on Light, Heat and Electricity,
fgiven at the School of Mines, and had some correspondence
with the Professor on the apparent differences in the diameter
of the moon. An experiment which he suggested was quoted
3)y Tyndall in an article published in the Philosophical Magazine
oi May 1862.

202 OBITUARY NOTICES.

In that year he was lecturing on scientific subjects to the
parents of scholars at the Exeter Buildings Ragged School, off
Sloane Street, and was giving similar lectures at the Sloane-
Street Y.M.C.A., in which he took a keen interest. He wrote
the astronomical notes for the Bible Class Magazine for many
years and supplied it with articles on various subjects, including -
an account of his first visit to Switzerland in 1868. His Swiss^
holidays were the only real relaxation he allowed himself, and
after some thirty-five trips he was as keen as ever to see the^
beloved mountains again. His last journey was undertaken
in 1914, when, after a considerably longer stay than he intended^
he returned in a repatriation train and arrived home on the last-
Saturday of the fateful August. In 1866 he was elected a
member of the Quekett Microscopical Club, and from the end of
that year to April 1916 he acted as its Honorary Reporter..
In July 1878 the Club presented him with a valuable gold watch
which he always used. His chief papers are published in the-
Journals of the Club * and his chief interest in life centred
round the friendships and scientific work which his membership
brought him. About the same time he became a Fellow of
the Royal Microscopical Society, whose proceedings he reported-
for over thirty years.

In addition to his more serious scientific work, which brought.
him correspondence from every continent, he was deeply in-
terested in the scientific aspects of Temperance and gave many
lectures on the principles involved. He constantly throughout.

* The following is a list of the more important contributions Mr-
Lewis made to the Journ. Q.M.C. 1. On the Male of Icerya Purchasi
from Natal, vol. iv. p. 29 (1889); 2. On the Stridulating Organs of
Cystocaelia immaculata, vol, iv. p. 243 (1890); 3. On a New Species^
of Aleurodes — A. aaparagi, vol. vi. p. 88 (1895) ; 4. On a Stridulating^.
Organ in a South African Ant — Strehlognanthns aethropicus, vol. vi^
p. 271 (189C) ; 5. Notes on some Australian Ticks received froi»
Mr. C. J. Pound, vol. vii. p. 222 (1899); G. A Contribution to the-
Life-history of Ixodes reduvius (Linne), vol. vii. p. 381 (1900); 7. On-
an Undescribed Species of Chelifer — Chelifer sculpturatus, vol. viii. p.
497 (1902) ; 8. Note on the Larva of Mantispa, vol. xi. p. 213 (1911 ) ~
9. Note on Solpuga ferox, vol. xi. p. 507 (1912) ; 10. The Early His-
tory of the Quekett Microscopical Club, vol. xii. p. 425 (1915). Mr^
Lewis's papers were generally illustrated by beautiful drawings exo-
cuted by his skilful pencil. [Editor.]

OBITUARY NOTICES. 203

life wrote articles and gave lectures of a popular character,
chiefly on subjects of a scientific nature.

In 1884 he removed to Ealing and soon joined the Ealing
Microscopical and Natural History Society. He served on its
Council and acted as a Vice-President.

For twenty-six years he was secretary of the Haven Green
Baptist Church and only resigned when failing health compelled
him to lead a less strenuous life.

He went to live at Blackheath in 1914, but continued to go
to business, travelling daily to Paddington, up to within a
month of his death. After four weeks of acute suffering, only
partially relieved by an operation, he died on June 10th, 1916.

Emily J. Lewis.

FREDERIC ENOCK, F.L.S., F.R.M.S., F.E S.

April 17th, 1845— Ma^/ 2m, 1916.

It is with great regret we record the death of Mr. Enock, which
took place at Hastings at the age of seventy-one years. Mr.
Enock was born at Manchester in 1845 and was educated at the
Society of Friends' School, Ackworth, Yorks. He joined the
Birmingham Natural History Society in 1865 and was for some
time latterly the Father of the Society. He joined the Quekett
Microscopical Club in 1871 and was elected an Honorary Member
in 1912. Mr. Enock had become well known to many by his
popular lectures on Insects, Spiders, etc., illustrated by coloured
drawings of exceptional skill and beauty. He also contributed
illustrated articles on Entomology to the popular magazines.
His chief claim to scientific distinction is the work he did on the
till then little-known group of the Myrmaridae, minute hymenop-
terous insects which pass their larval stage as egg-parasites. A
monograph on this group of insects — " fairy-flies " as Mr. Enock
styled them — had been in preparation for some years and we
are informed was nearly ready for publication at the time of
his death.

It is very probable that Mr. Enock was the first to mount
insects for the microscope "without pressure." At the Loan
Collection of Scientific Apparatus, held at South Kensington
in 1876, he exhibited " A Collection of Entomological Prepara-

JouRN. Q, M. C, Series II.— No. 79. 15

204 OBITUARY NOTICES.

tions for the Microscope." The following explanatory note
appeared in the catalogue of the Exhibition : "Some of these
preparations are mounted in a deep cell and by being treated
in a peculiar manner their natural form is preserved and the
internal structure of muscles and tracheae seen in their natural
positions."

205

NOTES ON THE COLLECTION OF BDELLOID AND

OTHER ROTIFERA.

By David Bryce.

{Bead January 23rd, 1917.)

Figures 1 and 2.

Since the first discovery of Rotifera by the illustrious Anton van
Leeuwenhoek rather more than two hundred years ago, these
most interesting microscopic organisms have captured the atten-
tion and the admiration of generations of microscopists, who
have willingly devoted much labour and much midnight oil to
the investigation of their structure, of their habits of life, of
their relationships among themselves, and of their affinities with
other groups of the animal kingdom. They have found in them
a most remarkable diversity of form, allied with the most com-
plicated and specialised organs, an astounding variety and
activity of movement, an infinity of devices for the capture of
their food, and in every direction an intelligence as surprising
as it is undeniable.

So far as I have been able to ascertain, the first English
naturalist who published any original observations with regard
to the Rotifera was Henry Baker, whose name is so familiar to
us all in connection with the well-known species Brachionus
Bakeri, so named by the celebrated 0. F. Miiller in honour of
our countryman. In his Emfloyment for the Microscope (1753)
Baker gave exceedingly quaint descriptions of the very few
species known to him, and these attracted great attention among
continental microscopists of the eighteenth century. After
Baker's time there does not appear to have been any original
work done by English observers in connection with Rotifera
until the middle of the nineteenth century. The only works

JouRN. Q. M. C, Series II.— No. 80. 16

206 DAVID BRYCE ON THE

which appeared in this country during the long interval were
Pritchard's Natural History of the Animalcules, published in
1834, and the same author's History of the Infusoria, published
in 1842. These books were little more than compilations, the
latter especially being largely based upon Ehrenberg's magnum
opus of 1838, and I take it that the first distinctively English
work in this direction of the later school of microscopists provided
with instruments of the modern type was the short paper pub-
lished by Brightwell in 1848, and followed by papers in 1849
by Dalrymple and by Dobie, and in 1850 by Gosse. Since that
time the lamp of the English enthusiast in the study of Rotifera
has been kept continuously burning, largely owing to the en-
couragement afforded by the Royal Microscopical Society and
by the Quekett Microscopical Club since its foundation in 1865.
No very great progress, however, had been made, when Hudson
and Gosse published in 1886 their epoch-making monograph,
The Rotifer a or Wheel Animalcules, which, together with the
Supplement of 1889, brought into focus all that had been
ascertained with regard to these highly organised animals, and
provided workers at home and abroad with a new starting-point
for further researches and wider investigations. Although the
difficulties which had previously beset the English worker, who
had laboriously endeavoured to identify his captures from the
figures and descriptions given in the 4th Edition of Pritchard's
Infusoria (the best book available in the early "eighties"), were
not altogether dispersed by Hudson and Gosse's work, they
were very considerably lessened and the fascinating study of the
Rotifera received an impetus which can be measured not only
by the tremendous volume of later literature, but also by the
long and exceedingly useful lists of more recently described
species so carefully compiled by Rousselet, and published from
time to time in the Jouryial of the Boyal Microscopical Society.

The species comprised in these lists total approximately nearly
one and a half times as many as had been included in Hudson
and Gosse's monograph, even after making liberal allowance for
insufficiently described and for twice- described animals. This
fact can only be considered as remarkable, when it is remembered
that these authors had furnished particulars of practically all

COLLECTION OF BDELLOID AND OTHER ROTIFERA. 207

the commoner and cosmopolitan forms and of a great many of
the rarer species.

If, however, Eousselet's lists are examined from the stand-
point of the habitat in which the various new species have been
met with, it will be apparent that while undoubtedly much the
greater proportion of these recent discoveries have resulted from
collections in areas not previously searched, nevertheless quite
a large number of the species have been found in habitats which
are more or less outside the ordinary activities of the pond-life
worker.

These notes on the collection of Rotifera will accordingly deal,
not only with the customary methods of Pond work, but also
with some less usual methods and with work which has little
or nothing to do with ponds at all. The Rotifera which are
to be obtained by the latter methods belong principally, but
not exclusively, to the order of the Bdelloida, to which I have
given my greater attention for many years past.

In speaking of Pond work, I use the phrase in its most com-
prehensive sense. I include in it not only the collection from
pools and ditches of all sorts, sizes and positions, but also from
running waters, and especially the smaller streams, rivulets or
mere runnels, from lakes, reservoirs and canals ; and even
from rock-pools and brackish waters.

The methods of collection which I refer to as customary are
the use of the net, the use of the dipping bottle, and the selec-
tion of portions of water-plants. These several methods are to
some extent provided for in the ordinary pond collecting outfit,
and it seems needless to describe them in detail ; but some
suggestions with regard to the net and its use may be worth
consideration.

The most suitable form of net for the capture of Rotifera
depends largely upon the character of the body of water in
which it is to be employed, and upon the habits of the species
which it is expected or hoped to capture. The habits of the
Rotifera in their turn depend principally upon the nature and
abundance of their special food. Those species whose food
consists of smaller or weaker organisms, either swimming or
floating, mostly swim themselves in search of their prey, and

208 DAVID BRYCE ON THE

they swim near the surface or deeper down according to the
level or zone in which the food organisms are most plentiful.
Another extensive series of species feed on the microscopic algae,
which grow more or less thickly upon the stems and leaves of
all kinds of water-plants, and, while readily swimming if dis-
turbed, seem to spend most of their lives in carefully seeking their
food where it grows, creeping all over the plants and nibbling
here and there. Others, again, are fond of temporarily perching
upon plants or confervoid threads, and feeding upon the organisms
carried to them by the currents set up by the play of their own
cilia. It is for the capture of rotifera of these various habits
that the ordinary use of the net is most advantageous. In
large ponds, where vegetation is frequently scanty, the net will
mainly capture species which habitually swim. In small, shallow
ponds with many and various water-plants, the second and third
groups may be expected to predominate. Such weedy ponds
frequently yield a much greater variety of species than the
larger ponds, especially if the net be roughly worked among the
vegetation to disturb those rotifers which may be creeping or
resting upon the plants.

Judging from recent photographs of happy Quekett excursion
parties, the net mostly employed in such pond work is a quite
small, single net of about the shape of an ordinary funnel. I
have rarely used a net of this small type, and cannot therefore
speak positively as to the results obtainable by its use. But it
seems to me to be only useful for the capture of such rotifers as
swim quite near the surface, or for use in very shallow ponds.

Now it has been shown by Dieffenbach * that in ponds of
moderate depth the swimming rotifers are throughout the day-
time in greatest abundance at a depth of about half a metre (say
20 inches) ; whilst during the night their distribution in the
water is practically uniform. It follows from this that the col-
lector who confines his use of the net in such ponds to the sur-
face of the water simply limits thereby the range of his captures.
The general object in using a net is not to capture a crowd of

* H. Dieffenbach and R. Sachse, Biologische Untersuchungen an
Riidertieren in Teichgewassern, Internationale Revne der gesamten
Hydrobiologie und Hydrographies Leipzig. Biol. Suppl. 1U12.

COLLECTION OF BDELLOID AND OTHER ROTIFERA. 209

rotifers of a very few species, but rather to secure representa-
tives of as many species as possible of those inhabiting the pond
at the time of collection. I prefer therefore a larger net, which
can be used not only for surface dipping, but also for deeper
work, as well as in larger bodies of water, where rotifers are
generally present in much fewer numbers. For this more general
use, I think that the depth of the net should be not less than
one and a half times the diameter across the mouth. When
collecting at a depth of several feet below the surface, it is easy
to turn such a net so that little water can enter it before it
reaches the desired depth ; it can then be opened fully, and
again closed before withdrawal.

The diameter of the net has also some importance ; a very
small net-ring would be of little use in working large bodies of
water, or for the plant-washing methods employed by Murray
to which I shall presently refer. For general work I prefer a
ring of not less than six inches diameter, as large, in fact, as will
easily enter a side pocket, and an oval outline is perhaps more
convenient than the round. In these days the net material is
usually Swiss "bolting silk" of suitable gauge (No. 14 or 15),
but Harring (who also, I think, prefers a large net) has used
China silk, and I have found Indian silk fairly satisfactory.

To the single net generally employed I have the objection that
it admits into the catch too many Entomostraca, larvae and
other unwelcome guests. I cannot affirm that I have at any
time seen Entomostraca attack rotifers, but I am certain that
they consume quantities of food which would otherwise be
available for the latter. If it is desired to keep the captured
rotifers alive, the Entomostraca, larvae, water-worms, etc., are
better left in their native pools. In recent years I have there-
fore made use of a double net of two different textures, the outer
of the customary material, and the inner of muslin sufficiently
close to act as a coarse filter to keep out, at least, the larger of
the objectionable intruders, while permitting rotifers to pass
through.

This double net had, however, the disadvantage that it was
impossible to get at the " catch " unless the inner net was un-
attached to the net-ring on one side. I happened to mention

210 DAVID BRYCE ON THE

this difficulty to Mr. Harring, of Washington, and he most kindly-
sent me a special metal tube, to take the place at the foot of the
net of the customary glass tube. The metal tube measures
3J inches in length, and IJ inch in diameter. At the lower
end it is closed. At the upper end it is provided with an easily
detachable and closely fitting rim, which is permanently attached
to the outer net in the same way as the usual glass tube or bottle.
The body and the rim of the metal tube are held together by
two bayonet catches (one at either side), which can be readily
disconnected, thus allowing the contents of the tube to be
poured into another receptacle. The metal tube has the further
advantage of avoiding the risk of breakage of the glass tube —
always at the least opportune moment— when the net is used
in ponds with a stony bottom. The whole arrangement is easy
to work and is effective in permitting the contents of the tube
to be secured without displacing or leaving unfastened the inner
net.

I believe that a fitting has been devised whereby the " catch "
is received into a short metal tube provided with a stop-cock,
but as a part of the latter projects considerably beyond the
surface of the tube, I imagine the arrangement to have disad-
vantages as compared with that now described.

But while the single or double net will secure a large propor-
tion of the species of Rotifera living in a given pond, it will not
secure all. Besides those species which swim, or which creep
over or perch temporarily upon water-plants, there is the impor-
tant and interesting group of rotifers which take up a per-
manent position on suitable plants, in many cases secreting or
constructing for themselves a sheltering tube ; and again another
group, which seek their food among the detritus at the bottom
of the pond. The former group are usually captured by bring-
ing home portions of water-plants, and for this purpose a selec-
tion of suitable portions is generally made at the pond-side with
the help of a pocket lens. There is perhaps no method of col-
lecting rotifers which requires more judgment and experience.
Great assistance is given by the use of a suitable receptacle for
the plants that are thus being looked over. One of the most
prominent members of our Club some thirty years ago used for

COLLECTION OF BDELLOID AND OTHER ROTIFERA. 211

this purpose what became known after him as the " Hardy flat
bottle," which can be easily made in the manner described later.

The aquatic plants most productive are those with finely
divided leaves, such as the various water Ranunculi, Cerato-
phyllum, Myriophyllum, etc. The ubiquitous Elodea canadensis
(better known perhaps as Anacharis) is also a favourite plant,
and the humble Duckweed Letnna minor should not be despised,
as it is much favoured by the plant-loving rotifers, and some
of the very earliest discoveries of such forms were made from
the examination of the pendant roots of this floating species.
The ivy-leaved Duckweed, Lemna trisulca, I have not found to
be so useful.

The portions of water-plants brought home can be kept alive
in glass jars or aquaria for periods varying according to the
plants themselves, some enduring under such conditions for
'months, others only a few days. It is desirable to have at the
bottom of such receptacles a moderately thin layer of muddy
sand to provide food for the small protozoa which in their turn
form the principal food of many of the Rhizotan Rotifera.

Of those species which habitually feed on the broken-down
vegetable substances at the bottom of the pond, ordinary pond
work with the net will only capture stray individuals. By the
use of the dipping bottle a better selection can frequently be
secured, either by taking home a single bottleful, or by passing
several bottlefuls through the net and taking the results home.

These bottom-feeding species are usually accompanied by
several species of the Gastrotricha, which are mostly of the same
habit. Dr. Voigt, a very successful collector of Gastrotricha,
during two years spent at the Plon Biological Station, made use
of the following more elaborate method :

A narrow-necked bottle of suitable capacity had its lower end
fixed into a canister partly filled with lead. To the canister
were attached two cords which were brought together in a ring
above the neck of the bottle. The whole was knotted to a line
and was then ready for use. The adjustment of the various
cords was so arranged that when the bottle was dropped into
the water at the desired spot, the mouth could be caused to lie
close above the muddy bottom, when the gradual filling of the

212 DAVID BRYCE ON THE

bottle could be judged from the rising bubbles. Some fifteen to
twenty such bottlefuls were thus collected and filtered at the
pond-side through a No. 16 silk net, and the small remainder
of water taken home. There it was first passed through a
coarse filter and then through a No. 18 silk. The new remainder
left upon the latter was next diluted with 1 to 2 c.c. of water
and examined drop by drop under the microscope. When Gas-
trotricha were in greatest abundance, two or three individuals
would be found in each drop. Dr. Voigt states that in the pond
to which he refers the water thus collected from the bottom
was very foul and smelt strongly of sulphuretted hydrogen.

I have not yet had an opportunity of trying this method, but
it seems likely to produce better results than can be obtained
with the dipping-bottle as commonly used, and although specially
devised and useful for Gastrotricha, it would probably answer
equally well for bottom-feeding Eotifera. It certainly has the
advantage that it can be used at a greater distance from the bank.

In some ponds where there are floating masses of confervae,
it is exceedingly useful to squeeze handfuls into the net, as many
species, notably of the Eattulidae, habitually feed either upon
the contents of the living cells or upon the semi-decayed and
broken-down portions. A small quantity of such algae may
be taken home to provide food for Rotifera in tanks or other
receptacles.

In working rock-pools it is desirable to shake in the net
handfuls of the more filamentous algae, but it must be remem-
bered that marine algae are extremely fragile and that their
decay is much more rapid than that of the fresh- water forms.

In searching for Rotifera in the Scottish Lochs, where vegeta-
tion is commonly very scanty, James Murray made use of a
similar method to obtain these and other microscopic animals
free from debris or larger intruders. In The Botijcra of the
Scottish Lochs he thus describes his plan : " Water-plants of any
kind, especially mosses and the finer- leaved flowering plants,
are collected along the margin of the lake. They are placed
inside a conical net of No. 6 Swiss bolting silk (an ordinary tow-
net). This is put inside another net of very fine silk (say No. 17
to 20). The whole is then immersed in the loch with the rims

COLLECTION OF BDELLOID AND OTHER ROTIFERA. 213

of the nets an inch or two above the surface. The water- weeds
are then stirred and shaken about and washed in the net as in
a bucket in order to detach the organisms which adhere to them.
The plants are then thrown away and the coarse net lifted out-
of the fine one and allowed to drip into it. We then have in
the fine net only microscopic organisms and fine sediment. It
has been found by experience that even very large Kotifers
will readily pass through the No. 6 net. Possibly giants like
Stephanoceros would not pass through, but such animals are
found by the direct examination of portions of water-plants
under the microscope."

Where the broad leaves of water-lilies, or even the floating
leaves of Potamogeton occur, it is worth while to gently scrape
the under surfaces, placing the result in a separate receptacle
for home examination. It is also worth while to occasionally
examine the egg-masses of w^ater-snails, when these are available
either in freshly collected weed or on the sides of aquaria.

In ponds, ditches, canals, rivers, etc., there is sometimes a
stone-faced bank or other stone- or woodwork in the water.
When it is possible I make it a rule to put my hand below the
surface to feel if there be a submerged growth of any kind upon
the accessible portions. Sometimes one finds short-stemmed
mosses, sometimes a thick furring of thread-like algae, some-
times only a slimy coating. Any of these are worth taking home
for examination. One can either pick off a little with the finger
and thumb or use a flat-sided tobacco tin to scrape off a square
inch or two. Several species of the Bdelloida (for instance, the
elusive Philodina erythrophthalma) are best got by this method,
which for a long time I thought had not been employed by
earlier w^orkers. Recently, however, I read in Eichhorn's in-
teresting book that he was accustomed to collect such material
about a hundred and forty years ago.

In some places it is possible to scrape from the upper portions
of partially submerged stone a dried encrustation of algae, which
had been submerged when the water was at a higher level.
Samples of such crusts should be taken, and treated as will be
presently described for dry mosses.

One more method of pond work should be kept in mind. It

214 DAVID BRYCE ON THE

is the examination of sucli animals as Asellus and Gammarus,
Nepa, Caddisworms and all kinds of larvae and water-worms,
and of various algae for those species of Rotifera which infest
them either as a source of food, as a means of transport or
merely as a shelter. It would occupy too much time and space
to enter into particulars of the various grades of parasitism
shown by such Rotifera. It suffices to say that some, indeed
most of them, are of the most interesting nature, and that here,
as in other matters, " it is the unexpected that happens." As
an instance of the " unexpected," I may mention the discovery
about fifteen years ago, by a young Italian student, in the course
of his studies for the Degree of Doctor, of three unknown species
of parasitic Rotifera in the gill-cavities and actually upon the
gills of the Freshwater Crab. Two of the species belonged to
the Bdelloida, and the third was a member of the genus Distyla,
a genus usually associated with weedy ponds and sphagnum bogs.
I think it is more than possible that if one of our younger
men would take up the study of parasitic Rotifera, as a special
line of investigation and in a systematic fashion, he would make
some very interesting and valuable discoveries. In the case of
Asellus and Gammarus, nearly every individual carries with it
several parasitic Rotifera, and the former animal is the usual
host for at least half a dozen different species. If an Asellus or
Gammarus be confined in a live box so that it cannot move
freely, the Rotifera will presently leave their positions. It is
then easy to remove the Asellus and to isolate the rotifers for
closer examination. Another method is to place several Aselli
or Gammari in a small, wide-mouthed bottle half filled with
water. The bottle is then well shaken, and the rotifers forcibly
detached from their hold. By pouring of! the water into a
stage trough, the rotifers, being carried with it, can be easily
picked out under the microscope and isolated. Asellus is usually
found among water-plants in weedy pools — Gammarus more
frequently in muddy ponds. In running water, however, the
latter can sometimes be found by lifting stones from the bottom.
Both of these hosts should be collected from as many different
localities as possible, and the results carefully noted for com-
parison one with another. The rotifers which are parasitic upon

COLLECTION OF BDELLOID AND OTHER ROTTFERA. 215

these two animals, and especially the Bdelloid species, are ex-
ceedingly difficult to keep alive after removal from their host.
Being apparently merely " lodgers," they do not in any way
feed upon their hosts, but I have no doubt that they derive
some direct benefit from the water-currents set up by the
branchial movements of the latter. When deprived of these
currents, and confined in a small cell, they rarely feed and soon
perish.

I come now to the work which I have referred to as outside
the ordinary activities of the pond worker, viz. the collection
and examination of moss.

The occurrence of certain Bdelloid Kotifera in moss had been
noted by Ehrenberg many years ago, in the Transactions of the
Berlin Academy, but only in scattered papers, all, I think, sub-
sequent to the publication of his great wovk Die In fusionsthiercheyi
in 1838, and these few and unemphasised references seem to have
escaped attention either in Germany or elsewhere. The re-
discovery by Milne and by Zelinka independently, about 1886,
that moss is a favourite home or shelter for such Rotifera, has
led to its being more systematically collected for examination,
and thus to the discovery of very numerous species which had
otherwise in all probability remained unknown.

Since 1886, the work of searching for moss-dwelling Rotifera
has been carried on steadily by several workers, and notably
by James Murray, whose untimely loss in the ill-fated Steffansson
Expedition is still fresh in our minds. Murray's magnificent
use of the opportunities afforded him by the Lake Survey Trust,
by the Shackleton Expedition to the Antarctic, and by the
Bolivian Boundary Commission has enriched our knowledge of
the Rotifera by over a hundred species, gathered in all quarters
of the world, and of these the greater number had been met
with in more or less direct connection with moss.

The work which has already been done by the various moss
enthusiasts has made a very notable alteration in our concep-
tion of the Rotifera in general, and of the Bdelloid Rotifera in
particular. Before 1886 the Bdelloida were looked upon as
being, like the majority of other Rotifera, inhabitants principally
of pools and ditches. It has now become well established, that

216 DAVID BRYCE ON THE

only a minority of the Bdelloida pass their lives in such habitats,
and that the greater number of the species of this group habi-
tually live in all sorts of situations, under all kinds of conditions,
away from pools and ditches, and are quite able to sustain life
and to thrive, if occasionally supplied with water by the fall
of rain, or even by the evening fall of dew. The knowledge of
such potentialities, not in one or two animals, but in a long
and constantly increasing array of species, must considerably
affect our estimate of the importance of Eotifera in the animal
kingdom.

Under the heading of Moss work I include the collection of
Fontinalis or similar mosses found occasionally in masses in
running waters in hilly districts, and of those finer-leaved forms
sometimes found in ponds ; of mosses growing on submerged
stones or wood ; of all bog-mosses, and especially Sphagnum,
whether in bog-pools or elsewhere ; of all mosses from dripping
rocks or wet banks ; of all tree-mosses and mosses on tree-
stumps ; of roof-mosses, wall-mosses and ground -mosses, and
even, and by no means least, of pavement -mosses. To put it
more briefly and comprehensively : of mosses from anywhere
and from everywhere. I also include the collection of liverworts
and even lichens, although the latter have only occasionally been
found to harbour Rotifera. For the present purpose it will be
convenient to divide these various mosses (and liverworts) into
two categories : the wet mosses, including all those which are
found growing in positions usually wet ; and the dry mosses,
comprising those which grow in positions usually dry — that is,
in dry weather. As the wet mosses are in some respects the
easier to deal with, I refer to them first.

Such mosses as Fontinalis are generally found growing in
some quantity and are frequently very j^roductive. Some hand-
fuls should be washed in the net and the results placed in a
separate bottle, as they must be looked over as soon as possible,
the water being so overburdened with impurities that it will
not remain sweet for long. I also take home a moderate supply
of the wet moss in a metal box, first allowing the water to drain
off, and then packing the moss very loosely. If thus treated
and kept in a cool place, even these coarse yet tender mosses

COLLECTION OF BDELLOID AND OTHER ROTIFERA. 217

will remain in good condition for some weeks, and thus provide
material for later examinations. If desired, some of the wet
moss can be placed in a glass jar with water, and this will live
well for some time. When an opportunity arrives for the ex-
amination of the moss stored in the metal box, a portion should
be placed in a wide-mouthed bottle of 4 to 8 oz. capacity,
and the bottle half filled with water. To dislodge any animals
attached to it, the moss is then stirred vigorously about with
the butt of a penholder or other suitable weapon, and afterwards
removed. After allowing the water in the bottle to settle, a
portion is poured into a stage trough and searched under a low
power for swimming species. The trough should be large enough
to permit of the introduction and free use of a fine pipette. If
no swimming species are present, or those seen are not wanted,
I pour away the greater part of the water from the bottle, and
after shaking up the remainder, refill the trough. The latter
is placed in a sloping position, so that the sediment may settle
on one side. When the water has fairly cleared, the trough
is transferred to the stage of the microscope (which, it is under-
stood, is inclined at a convenient angle), that side of the trough
on which the sediment has fallen being kept underneath. Any
Rotifera present will mostly be found moving among the sedi-
ment, and individuals desired for closer examination can be
picked out with the pipette. If the sediment lie thickly, it is
sometimes desirable, after some minutes in the inclined position,
to stand the trough upright, when most of the sediment will
fall to the bottom, leaving many of the rotifers attached to the
glass side. With a little care it is not difficult with the tip of
the pipette to push the rotifer from its hold without injury, and
to draw it into the pipette before it can regain its position. The
operation requires a little practice, as it must be done while the
trough is on the stage of the microscope. The trough is held
firmly with the left hand, and the pipette managed with the
right. For all preliminary work in searching through pond
gatherings or moss washings I use a 1-inch objective with an
A or No. 1 eye-piece. The further treatment of the selected
specimens will be described later.

When the contents of the trough have been sufficiently searched,

218 DAVID BRYCE ON THE

and all the desired specimens picked out, the trough can be
emptied and refilled from the stock bottle and so on. If further
examination of the stock is to be deferred to another occasion,
I pour away gently the greater part of the remaining water,
and replace with clean water before placing the stock aside.

I have not myself met with Fontinalis in the London district,
only in really hilly country. In some of the Epping Forest
ponds I have occasionally found masses of finer-leaved mosses,
which I have treated in the same way.

A more easily obtainable moss is Sphagnum, which lingers on
in greatly reduced quantity in some parts of Epping Forest,
whilst on the moors of the north and west country it is generally
abundant wherever there is boggy ground. Although several of
the Rotifera which frequent this moss are also found in mosses
growing in dry situations, there are a few species, such as Hahro-
trocha angusticollis, H. lata, Scepanotrocha rubra, Stephanops
stylatus, S. tenellus and Distyla agilis, which are very rarely
found elsewhere. Besides these there are at least two species
that habitually live in those remarkably large cells which form
the cortical layer of the stems of the side-branches of
Sphagnum. Each of these cells is provided by nature with
an external opening, which admits the water within the cell-
cavity. In the dim ages of the past, Hahrotrocha Roe/peri and
HahrotrocTia reclusa have discovered the possibilities of such
cells for the purpose of shelter, and they have, in fact, become
tenants at will of these single-roomed, self-contained residences,
taking possession by simply squeezing through the doorway —
the natural orifice of the cell. Once inside, the rotifer finds itself
in sufficiently roomy quarters, where it can turn about, and if
all goes well, lay its eggs, and, so to speak, bring up its family,
living at peace and paying no rent. When it is hungry it pushes
its head and neck through the orifice and commences to feed.
To find these animals in situ it is necessary to strip the leaves
off the side-branch. It is not known definitely whether they
inhabit all kinds of Sphagnum. I have seen some forms in
which the cortical cells had openings which seemed too small
to permit the entrance of the rotifer.

The general treatment of Sphagnum differs somewhat from

COLLECTION OP BDELLOID AND OTHER ROTIFERA. 219

that necessary for the Fontinalis group of mosses. Sphagnuni
should not be washed roughly in the net, it is too fragile for
that method. It is better to simply squeeze handfuls into the
net, and it is also useful in suitable places to turn up one's sleeve
and plunge a bottle deep down among the long roots and there
fill it with the water and to empty it into the net a few times.
Sphagnum frequently harbours several species of Ploima, and
especially members of the family of Cathypnidae, even when it
is not growing in or alongside a pool. The swimming species
are most plentiful in Sphagnum growing in bog pools, and are
mostly species which rarely or never occur in the ordinary
pools and ditches. The rotifer worker should make a point of
searching Sphagnum wherever he finds it growing. The results
of moss squeezing should be examined as soon as possible, as
the swimming species are mostly delicate forms which do not
live well in confinement. Sphagnum should also be brought
home, and if lightly packed in a metal box will keep in good
condition for some weeks. It should not be squeezed before
packing, and it must not be allowed to get dry. I think it best
to wash it in very small quantities when making a stock, and
treating it comparatively gently. I have also had good results
from packing it fairly tightly in a bottle, adding sufficient water
to thoroughly soak it. When I desired to examine it, I shook
the bottle and then poured some of the water into the stage
trough. But with this method there is some risk of the
Sphagnum fermenting, with fatal consequences to all Kotifera.
Wet mosses from dripping rocks or wet banks should be dealt
with in the same way as the dry mosses to which I next refer.
They should be stored in metal boxes or in bottles, and not
allowed to become dry.

Mosses which grow in positions usually dry should not be
gathered during rain or even shortly after being wetted by rain
or dew. They can be kept either in metal boxes or in paper
bags. The grease-proof paper now so generally employed
makes a good wrapping for small packets.

The possibility of getting living rotifers from dry material is
a consequence, fortunate for the microscopist, of the wonderful
capacity of certain Rotifera of retaining their life in spite of

220 DAVID BRYCE ON THE

being apparently absolutely dry. In some books of reference
I have seen statements which implied that all Kotifera could
submit to desiccation and still survive. The real fact is that
this remarkable property is practically confined to the Bdelloid
Rotifera. In all the numerous samples of dry material which
I have examined, I have been able to find and to revive only
four different species which did not belong to the order of the
Bdelloida, and even in this order the property is by no means
universal. As is well known, the reproduction of Bdelloid
rotifers takes place in two distinct fashions : in some genera the
various species produce living young ; in the other genera the
various species produce eggs, whose segmentation does not com-
mence until after their extrusion by the parent. It is found as
a general rule that viviparous species do not live in situations
where they are liable to be frequently dried up. Such places
are almost exclusively inhabited by species which are oviparous.
There is thus presumption of a direct connection between the
habitat and the method of reproduction. In dry mosses one
expects therefore to find only oviparous species, and very few
exceptions to this rule are known.

The process of preparing themselves for their recurrent
passive condition can be shortly described. By some means
or another the animals are sensitive to the approach of the
danger point of the evaporation of the water in which they
are living. When thus warned they become restless, and
finally utilise the telescopic capacities of their structure to
withdraw the head and neck, and the foot, within the skin
of the central body. From the skin now remaining ex-
posed is exuded a liberal covering of some secretion, which
hardens into an airproof coating as the animal is gradually left
dry by the vanishing water. To be effective, the operation
of exuding the secretion seems to demand a certain amount of
time. If the animal be allowed to dry up quickly, it invariably
fails to revive again if kept more than a very few minutes before
being remoistened. On a glass slip that is free from sand or
fragments of detritus, the drying takes place too rapidly. If,
however, there is present a little sand around which the water
clings, the rotifers have a better chance of assuming their air-

COLLECTION OF BDELLOID AND OTHER ROTIFERA. 221

proof investment. Under natural conditions there is of course
plenty of sand or vegetable fibres.

Once safely covered with his " airproof," the rotifer can
endure months of desiccation, and in some cases they have been
revived after several years. But the longer the period of
desiccation, the smaller will be the proportion of the individuals
that revive. In other words, the best results are obtainable
from dry mosses when they are freshly gathered or, at least,
not more than three or four months old.

When " wet " mosses are washed, the rotifers are active at
once when the moss is placed in water ; they have, in fact,
never ceased their active life. They may have contracted
themselves and may be lying motionless, but that is because
they have been disturbed, and are temporarily frightened or
simply timid and cautious. When " dry " moss is washed,
some time must be allowed for the water to dissolve the protec-
tive coating, and to stimulate the dormant life to a renewal of
activity. The time varies according to the period which has
elapsed since the moss was collected. In the case of mosses
recently gathered, it may be as short as ten minutes ; in that
of mosses which have been in hand for many months, it may
be several hours before the animals begin to show signs of re-
turning animation. Whatever be the period, part of it can be
usefully employed in " clearing " the water of the " stock."

Mosses from wet banks and all dry mosses should be gathered
with as little earthy matter about their roots as can be managed
without dislodging animals adherent to the stems and leaves.
With short-stemmed mosses some thickness of earthy material
is unavoidable. Before washing such material, I generally shave
or scrape off the moss-fibres just above the surface of the soil,
to avoid putting the latter in the water. Even then a consider-
able proportion of dirt particles in the stock must always be
expected in washing dry mosses. Most of it is usually sand,
which will settle quickly when the stock is stirred or shaken up,
and is not harmful. But there is always a proportion of very
finely divided particles which remain suspended in the water after
the sand has settled. These finer particles doubtless include
great numbers of bacteria and much decaying organic matter.

JouRN. Q. M. C, Series II.— No. 80. 17

222 DAVID BRYCE ON THE

If these fine particles are not removed from the water, the
stock goes quickly sour and every rotifer present is poisoned.
It is therefore essential that the water should be cleared ; and
this process, and the time which elapses before the rotifers regain
activity, constitute the main differences in the treatment after
collection of dry mosses as compared with that of wet mosses,
such as Fontinalis or Sphagnum.

The moss is placed in a wide-mouthed bottle which is then
filled nearly full with water. The capacity of the bottle may
range from two ounces upwards according to the quantity of moss
to be dealt wdth and its condition as regards adherent dirt.
Clean mosses such as are gathered in woods and from tree
trunks can be washed in larger quantities than short-stemmed
mosses from the ground or from walls. As a rule, the moss
should not more than cover the bottom of the bottle. When it
has become thoroughly soaked, the moss is well stirred about
and removed. The water in the bottle is allowed to settle for
two minutes, in which time all sand and all rotifers will fall
to the bottom, leaving the water more or less cloudy or even
opaque. Some two-thirds is to be carefully poured away, and
the bottle refilled. The procedure is repeated until, on refilling,
the water is not perceptibly cloudy. After another two minutes
the greater part is poured away, leaving only a remainder to be
searched through as already described. A stock prepared in
this way will generally keep in good order for some weeks, giving
time to make a very thorough examination of the material, if
it is found to be productive. A simpler plan is to place some
moss in a bottle with a little water, and after allowing time for
the rotifers to revive, to shake the bottle and then pour off the
water into the stage trough. This plan answers quite well up
to a point with fairly clean moss, but according to my experience
the stock does not keep nearly so well as that which has been
systematically cleared.

The sandy sediment which collects in roof-gutters, whether
in town or country, nearly always harbours some species of
Bdelloid Rotifera, and these can be secured by treating the
sediment in the same way as dry mosses. In town samples the
stock is usually very foul, and the water has to be changed many

COLLECTION OF BDELLOID AND OTHER ROTIFERA. 223

times before the stock is fit for examination. I have also on
some occasions obtained Bdelloida by washing dead leaves, and
even from tufts of the common Thrift. I have no doubt that in
wet weather and in places where disturbance of the surface soil
is infrequent, Bdelloid Rotifera, and especially young individuals,
creep about more freely over the ground than has yet been sus-
pected. Moss therefore, although the most convenient for the
purpose of the student, is not to be regarded as the only habitat
of those Bdelloid Rotifera which live away from pools and ditches.
In this connection I may mention some very curious habitats
which have been brought to my notice. Some years ago Mr.
Paulson handed me some specimens of a Lichen, Parmelia
revoluta concentrica, which has the abnormal habit of growing
concentrically all round some suitable loose core and thus pro-
ducing an egg-shaped or spherical ball which is blown hither
and thither by the wind on the open downs. In examining
some examples collected on the South Downs, Mr. Paulson had
discovered some Bdelloid Rotifera sheltering within the inner
recesses. These rotifers proved to belong to the species Macro-
trachela nana, a form usually met with in ground-mosses. At
a later date I received from Mr. Harring a tube of soft fragments
of rotten wood in which rotifers had been found by one of his
friends. On first examination I was unable to find anything
alive except some eel-worms, but I kept the material moist, and
some six months later a second examination revealed numerous
examples of the same species, Macrotrachela nana, which had
been found in Mr. Paulson's specimens of Lichen. These two
instances give ample proof of the potential adaptivity of the
moss-dwelling Bdelloida.

Again, it will be remembered that Mr. Scourfield made re-
cently some investigations as to the inhabitants of certain small
collections of water among the exposed roots of trees, and that
in the small receptacles formed by the natural twistings, etc.,
of the main roots he discovered a water- flea previously unknown.
He also found numerous Bdelloid Rotifera, which I was able to
identify as the rare Habrotrocha hidens (Gosse), and this species
occurred dominantly in two different gatherings.

I come now to the after-treatment of the rotifers selected by

224 DAVID BRYCE ON THE

means of the pipette from the various gatherings or washings
examined in the stage trough. When picking up the rotifer it
is desirable to take with it as little water as possible. This can
be attained to some extent (1) by the use of a very fine pipette
of the form shown in fig. 1, e ; (2) by not filling the stage trough
more than 1 inch deep. Having captured the rotifer wanted,
I gently blow out the contents of the pipette upon a specially
prepared cell-slide (fig. 1, d), depositing the water near the centre
of the cell. It is essential that when the cover-glass is placed
in position, the film of water should not much exceed J inch
in diameter, and that it should not at any point reach the cell-
wall, the effect of these conditions being not only to provide in
the cell a supply of air, but also to very considerably retard
evaporation of the fluid contents. In most cases the water
taken up by the pipette and deposited in the cell exceeds the
desired modicum, and some must be withdrawn. The use of
blotting paper for this purpose I find to be slow and risky. The
first step is to remove with a forceps to another cell any coarse
sand or large fragments of plant or moss. This done, I generally
draw up the surplus water into the pipette by capillary attrac-
tion only, ensuring that the inflow is very slow by keeping my
finger lightly pressed on the upper orifice. The water removed
is deposited in another cell, in case, by misadventure, the rotifer
may have been caught up as well. If the captured animal is a
Bdelloid, it has probably contracted itself when first picked
out, and it is well to wait a few minutes before removing the
surplus fluid, to give it time to re-extend and regain its foot-
hold. But even with all possible care, the animal will some-
times get stranded in the pipette. Therefore, when the capture
is of more than ordinary importance, I adopt a slower but safer
method. Placing the cell-slide flat ujion my table, I take an-
other similar slide, and lower it in a horizontal position, face
downwards, over the flrst until it rather more than touches the
drop of water. It is then carefully raised and brings with it a
small portion of the fluid, and this is examined under the micro-
scope to make sure that the rotifer has not been picked up. The
procedure is repeated until the water is sufficiently reduced. If
the rotifer be a " free-'swimmer," it may be desirable to restrict

COLLECTION OF BDELLOID AND OTHER ROTIFERA. 225

its movements, and this can be effected either by placing in
the water a very few fibres of ordinary cotton wool or a few
threads of Spirogjrra or similar Algae. When the cover-glass
is placed in position the water-film should be intersected by a
thin network of fibres and broken up into numerous small en-
closures within one of which should be imprisoned the rotifer.
When the captive is a Bdelloid, this procedure is unnecessary.
For ordinary observation Bdelloida must never be held in any
degree, or they wall not display the corona. In the cells which
I use they have plenty of room. The water having been sufii-
ciently reduced, the cover-glass is put on carefully and the slide
placed on the stage of the microscope to make sure that the
water-film does not reach the cell- wall. If it does, the cover-
glass must be taken off and put on again until all is right. In
such cases it is often advantageous to turn the cover-glass partly
round before replacing it. When successfully carried through,
the operation, which takes so many words to detail, occupies
very little time. I have described the procedure as if dealing
with a single rotifer, but in practice I generally pick out several
examples and place all in one cell before removing the surplus
water. I have had as many as seven different Bdelloid species
living happily together for weeks in the same cell, having been
introduced one by one in the way described.

With my cells I use 1-inch square cover-glasses, that size
being much more easy to manage when the cover has to be
temporarily taken off.

Many Bdelloida are much scared when transferred to a cell,
and either remain obstinately contracted or march about rest-
lessly and vigorously. As many species cannot be identified
with certainty unless seen when feeding quietly and well placed,
I find it best to leave such animals undisturbed in the cell for
examination on another evening.

I have not attempted to keep any Rhizotan species in these
small cells, and I find that very few of the free-swimming Ploima
will survive in such restricted quarters for more than a few
hours. When examination of these animals is finished, it is
best to restore them to the original gathering. Such exception-
ally hardy forms as Diaschiza gracilis, Metopidia lepadella,

226 DAVID BRYCE ON THE COLLECTION OF ROTIFERA.

Monostyla cornuta and Distyla inermis will live for a few days if
some fragments of plants, etc., are left in the cell to provide
some food for them. Nearly all the moss-frequenting Bdelloida
will live for at least a month under the same conditions, but
the larger pond-dwelling species of the genus Rotifer seldom live
more than a few days. Hitherto I have not supplied the cap-
tives with food to supplement that present in the cell, merely
replacing when necessary the water lost by evaporation. I am
now experimenting upon the results attainable by the supply
at intervals of small quantities of microscopic algae of the
nanno-plankton type, but so far with indifferent success.

The method I have indicated of placing the droplet of water
(containing the rotifer) near the centre of the cell, and on no
account permitting the fluid to extend to the cell-wall, is so far
effective in retarding evaporation that even during summer
temperatures the cells can be left in any cool place from one
day to another without danger to the contents. For longer
periods it is desirable to store the cells in a " damp chamber."
That which I use (fig. 2) consists of three parts : an ordinary
bell glass of about 7J inches diameter and 8 inches high, a
shallow basin of about 8 inches diameter at the bottom and a
staging of galvanised wire (fig. 2, d), on which there is room for
some thirty glass slips laid horizontally. The bottom of the dish
is filled with water and old moss. In this chamber I have re-
peatedly kept cells undisturbed for more than three weeks,
without their contents being dried up or the captive rotifers
killed.

The advantages offered to the student of Rotifera by the
use of these cells, etc., for winter work scarcely need to be pointed
out. At a season of the year when it is difficult to screw up one's
courage to a long tramp to a distant and desolate pond, one
can have resort to the mosses stored up from more pleasant
summer excursions and from them obtain animals which will
interest and repay repeated examination.

I conclude these notes with figures of various pieces of
apparatus which I find useful, and particulars of their con-
struction in so far as they are of home manufacture.

The Hardy flat bottle (fig. 1, a, b) is in the form of an elongated

^

7

b

y

■

■ ' ■

Fig. 1.
a, b, One-half actual size. c, d, e, Actual size.

228 DAVID BRYCE ON THE

trough. For the framework take an oblong piece of sheet-rubber
5J inches x IJ inch, and J inch thick. Cut this lengthwise
into three slips J inch wide. Two of these will form the sides,
and the 3-inch bottom is cut from the third, leaving a length
of 2J inches to be cut again for a loosely fitting " cork " (fig. 1, b).
For back and front provide two pieces of thin plate glass 6 inches
X 3. To one of these cement the bottom slip of rubber and
the two slips for the sides, making good joints between. After
they are set hard, fix the other glass in position. I find in prac-
tice that troughs built up of three pieces of rubber cemented
together last quite as well as those wherein the rubber frame
is of one piece, as originally specified for this " bottle." The
various dimensions and the thickness of the rubber can be varied,
but those stated make a convenient and useful size. When
cutting rubber the knife should be kept wet.

The stage troughs (fig. 1, c) are made in a similar way, but from
rubber J inch thick. The front and back are of thinnest plate
glass 2 X 2J inches. The rubber is cut into strips about f inch
wide and into lengths of 2f inches for the bottom, and IJ inches
for the sides. These are cemented into position on one glass,
and when hard set the other glass is fixed on. These measure-
ments leave a small margin of glass at sides and bottom, and
the glass should be so afl&xed that the trough will stand upright.
For cementing I use ordinary gold size, sometimes mixing with
it some powdered colour to harden it.

My ordinary "cells" (fig. 1, d) have the cell- wall made from thin
lead-foil such as is used for capsules ; for very shallow cells I
use tin-foil. I cut this material into 1-inch squares and cut out
the inner square of J inch, leaving a square frame J inch
wide, which is cemented to the centre of a thin glass slip (3x1).
Care must be taken to press out superfluous cement so that only
the smallest effective modicum is left, and the cell-wall must
be perfectly smooth and not thicker at one side than the other.
Otherwise, when in use, capillary attraction will draw the cell
contents to the thinner side. The same result follows if the
lead-foil itself is too thick, but that can be remedied by plan-
ing the surface carefully with the edge of another glass slip.

The fine pipettes (fig. 1, e) are made from glass tubing of small

COLLECTION OF BDELLOID AND OTHER ROTIFERA.

229

diameter. " Small J inch " is particularly good. It is procur-
able at the chemical shop, and costs 3d. per length of 3 to 4 feet.
The upper end of the pipette, on which the finger tip is to be
pressed, must first be seen to. It must be cut clean, so that
when the finger is firmly pressed on it no air can pass. A slight
inequality can be reduced by holding the end in the flame of a

E

L

I

Fig. 2.
About one- fifth actual size.

gas jet and bringing it just to the melting point. If too rough
or jagged, a fresh end must be made. Glass tubing is cut by
nicking it with a three-sided file and breaking across. When
the end is satisfactory, the piece of tubing is held in the gas
flame about 3 inches from the end, and heated until it begins
to bend. As it bends, the two extremities are pulled steadily

230 DAVID BRYCE ON THE COLLECTION OF ROTIFERA.

apart until tlie tube is divided, each piece having a tapering
point bent over to one side. A small terminal opening (say about
■^^ inch diameter) at right angles to the tip of the pipette is now-
made by careful grinding on a stone or the face of a file. It
is useful to finish off the pipette by marking it near the upper
end with a ring of red sealing-wax or bright-coloured cement, to
make it conspicuous and easily found. A pipette used for any
special purpose, such as dealing with narcotised specimens,
should have a special mark, and be kept apart.

I find a pipette of 3 inches length the most convenient for use
with the stage-troughs described. The larger pipettes wdth
rubber teats or covers take up too much fluid and are more
difficult to control, although admirable for dealing with larger
quantities.

The staging (fig. 2, a, b, c), which forms an important part of the
damp chamber (fig. 2, d), is made from galvanised wire, with the
help of pliers. Tw^o pieces of stout wire are each bent to the
form shown in lateral view fig. 2, a. With rather finer wire
passing from one upright to the other a series of shelves is made
as shown in fig. 2, b. Finally the two pieces are bound together
at each end as in fig. 2, c (end view).

The bottom of the dish being filled with old moss (kept very
wet), the feet of the staging are pushed into the soft layer, which
gives a sufficiently safe foundation.

JouTU. Quekctt Microscopical Club, Ser. 2, Vol. XIII., No. 80, April 1917.

231

THE PRESIDENT'S ADDRESS.

THE CHESSMAN SPICULE OF THE GENUS LAT-
RUNCULIA; A STUDY IN THE ORIGIN OF SPECIFIC
CHARACTERS.

By Arthur Dendy, D.Sc, F.R.S.
Professor of Zoology in the University of London.

{Delivered February 21th, 1917.)

Plates 15-17.

It is very well known that there are certain types of tetraxonid
microscleres in which the spicule consists of an elongated, rod-
like axis with whorls of outgrowths arranged at intervals along
it. As a result of the study of some novel varieties of this type
met with amongst the sponges of the " Sealark " collection,
it occurred to me that the position of these whorls might corre-
spond with that of the nodes in a vibrating rod, and that thus
the form of the spicule might be determined largely by a well-
known physical cause, the deposition of silica taking place
chiefly where the rod was in a state of rest. The stream of water
constantly flowing through the canal- system of the sponge seems
to afford a sufficient explanation of such vibration, for the
developing spicules are imbedded in the very soft, gelatinous
mesogloea in the immediate neighbourhood of the canals. I
submitted the problem to my mathematical colleague, Professor
J. W. Nicholson, of King's College, and he was good enough to
make some calculations which entirely support this theory. I
do not propose to trouble you on this occasion with a detailed
account of our results from the physical point of view, as we
hope to publish a joint paper on the subject very shortly. In
searching for further evidence, however, I was led to make a
somewhat elaborate study of the so-called chessman spicule in
two species of the genus Latrunculia, and the development of

232 THE president's address.

these spicules proved to be so extraordinarily interesting that I
thought it might afford a suitable subject for my address to
you this evening.*

A good deal has been written on the development of sponge-
spicules, and some of the published accounts appear to be very
contradictory. It would seem from the observations which I
am about to lay before you that this development is by no
means so simple an affair as is often supposed, but is in reality
a very complex process, the course of which is determined partly
by physical and partly by what may be termed biological factors.

The two species of Latrunculia in question, L. hocagei and
L. apicalis, were both obtained by the Challenger Expedition at
Kerguelen, and the latter also off the mouth of the Rio de la
Plata, and were described by Mr. Ridley and myself in the Re-
port on the Challenger Monaxonida, published thirty years ago.
Only the adult form of the curious chessman spicule was, how-
ever, described, and I had no idea, until I came to re-examine
them the other day, that my preparations — consisting chiefly of
a large number of sections stained with borax carmine and cut
by the ordinary paraffin method — contained an almost perfect
series of developmental stages.

Much as I deprecate the unnecessary introduction of new
technical terms, I must venture to suggest that in future these
spicules should be called " discorhabds " instead of " discasters."
The latter term, first used, I believe, in the Challenger Report,
was based upon a complete misconception as to the nature of
the spicule, which does not belong to the astrose series at all,
but is clearly shown by its development to be a linear type
modified by the addition of disk-like outgrowths or whorls of
spines.

The fully grown discorhabd of Latrunculia hocagei (fig. 7) is
about 0"07 mm. in length — or height — and really bears consider-
able resemblance to a chessman. It consists of a straight, stout

* A brief account of the gross features of the development of the
chessman spicule in Latritticulia lendenf eldi has been given by Hent-
Bchel (Monaxone Kieselschwammo und Hornschwamme der deutschen
Sudpolar-Expedition, 1901-3). The course of events in that species
evidently agrees in general with what occurs in L. bocagei and L.
apicalis.

THE president's ADDRESS. 233

shaft, expanded at the lower end to form a knob-like base —
which I propose to call the manubrium — ornamented with two
circles of short spines. For some distance above the manu-
brium the shaft is free from outgrowths, but a little beyond the
middle of the spicule there comes a whorl of three flattened
lobes with denticulate or crenate margins, followed after a short
interval by a similar whorl, and then, after another short in-
terval, by a third whorl which differs from the other two in not
being subdivided into three lobes. Following immediately on
the third whorl is the broad, hemispherical apex, provided with
a number of short, capitate spines and forming a sort of crown.

As we shall have to refer to them frequently and individually
in what follows, it is necessary to distinguish the three whorls
by special names, and for reasons connected with their develop-
ment I propose to call them, in the order in which I have just
described them, the median, the subsidiary and the apical
whorls respectively (fig. 7, m.w., s.w. and a.w.).

In Latrunculia apicalis (figs. 20-24) there is a very interesting
specific difference in the form of the discorhabd, for, beyond the
apical whorl, the spicule, instead of terminating in a crown of
capitate spines, is produced into a very long, slender, tapering
process resembling the " leader " of a growing fir-tree, to which,
indeed, the spicule bears a striking resemblance. We may call
this the apical prolongation {a.p.). Near the base of this process
there is a single or double circlet of small spines, which may
perhaps be regarded as a second subsidiary whorl (s.w. 2). An-
other difference, which is of considerable interest in connection
with the vibratory theory, lies in the fact that the median whorl
is a little farther from the apical whorl than in L. bocagei, being
approximately midway between the apical whorl and the
manubrium. The length of the fully grown spicule is about
0-126 mm.*

Of course individual variations in the form of the discorhabd

* Kirkpatrick, in his Report on the Tetraxonida of the National
Antarctic Expedition, has described two supposed varieties of L.
apicalis, in one of which two forms of discorhabd occur, one with and
the other without an apical prolongation, I doubt whether either
variety should be assigned to L. apicalis.

234 THE president's address.

occur. The subsidiary whorl is occasionally developed between
the median whorl and the manubrium, instead of between the
median and apical whorls, but I have only seen this in the young
spicule (fig. 17) ; or the subsidiary whorl may be missing alto-
gether (fig. 21). A curious abnormality is represented in fig. 22,
where a branch is given off from near the base of the apical
prolongation and the chief subsidiary whorl is defective on the
same side of the spicule.

It is obvious that the form of these spicules is remarkably
well adapted to the purpose for which they are employed by
the sponge, that purpose being the protection of the external
surface. Here they are arranged in a dense forest, with their
bases or manubria firmly implanted in the fibrous outer layer
of the cortex, and their apices projecting freely. Placed close
together, shoulder to shoulder, they form an admirable defence
against the attacks of parasites or other enemies.

In view of their final disposition at the surface of the sp.onge,
and the remarkable manner in which their shape conforms to
the requirements of that situation, with base and apex each
apparently differentiated for its special function, it is not a little
surprising to find that these curious organs of defence originate
and go through the whole of their development in the interior
of the body, beneath the cortex and far removed from the
position which they are destined and adapted to occupy. Any-
body who cared to speculate about the purpose and intelligence
exhibited by sponges would find here abundant material for
cogitation. We can imagine him saying " See how the sponge
first of all shapes these spicules into appropriate weapons, and
then carefully arranges them in their thousands, all in the posi-
tion of maximum efficiency ; surely this implies something more
than mere mechanical necessity, some purposive action such as
we ourselves are capable of performing." It is perhaps quite
as remarkable a case as any of those which have recently been
brought forward by Mr. Heron-Allen from amongst the Fora-
minifera. It is, moreover, by no means unique amongst
sponges, for we see the same phenomenon in the case of the
cortical layer of sterrasters in the genus Geodia, and other in-
stances are also familiar to the student of this group. The most

THE president's ADDRESS. 235

exact parallel that I know of, however, occurs in quite a different
group of animals — the Hoplonemertines. These remarkable
worms possess a long, eversible proboscis, armed at its tip
with a single calcareous stylet, shaped like a nail. The head of
the nail is fixed in a kind of handle, formed as a secretion by
certain glandular cells. But the stylet does not develop in this
position ; a supply of them is formed — apparently by the secre-
tive activity of special mother-cells — and kept in reserve in little
sacs which lie at the side, not far from the handle, and it seems
that wlien one stylet is broken or worn out it can be replaced
by another taken from one of these armouries.

But even if we assumed, which I am far from doing, that the
removal of the discorhabds from their places of origin and their
arrangement at the surface was due to some intelligent and pur-
posive action on the part of the sponge, we should hardly be any
nearer to an explanation, for the sponge is apparently devoid
of any organs through which its intelligence might operate in
bringing about such a result. The mystery will be cleared up
only when we are in possession of adequate information as to the
various changes through which the sponge passes in its develop-
ment as a whole. We cannot solve such problems by the con-
templation of completed results, and the truth of this statement
is very well illustrated by the development of the discorhabds
themselves, to the consideration of which we must now
pass on.

It is generally believed that the siliceous sponge-spicule,
whether microsclere or megasclere, originates within a mother-
cell or scleroblast. In some cases it is supposed that the entire
growth takes place within such a cell, but where very large
spicules are formed it is suggested that the later additions of
hydrated silica, or opal, are contributed by accessory silico-
blasts. It has also long been recognised that the secretion of
silica takes place around an axial thread of different but un-
known composition, the position of which is frequently indicated
by the presence of a more or less distinct axial canal in the fully
developed spicule. The mode of origin of the axial thread, or
" protorhabd " as I now propose to term it, is entirely unknown,
but it seems generally to be assumed that it arises in the same

236 THE president's address.

mother-cell which secretes the silica. About the actual exis-
tence of these two constituents of the spicule — the protorhabd
and its coating of silica — there can be no doubt, but their mode
of origin is a much more difficult question, upon which I hope
that the following observations may throw some light.

It is extremely rarely, if ever, that the protorhabd has been
detected as an independent structure, before the commencement
of secondary thickening by the deposition of silica. In both
our species of Latrunculia, however, we find something at any
rate very closely approaching to this earliest stage, though it is
difficult to be certain that there is still no siliceous deposit at all.
Scattered sparsely through the choanosome, beneath the cortex,
occur a number of very slender rods (figs. 1 and 8) about 0'04
mm. in length, which, unlike the silica which is subsequently
deposited around them, stain rather deeply with borax-carmine.
It is difficult to determine the exact shape of their extremities,
but in L. apicalis one end appears to be more sharply pointed
than the other, though this may not be a constant character.

I have not been able to demonstrate that these protorhabds
arise within single mother-cells, though it is quite possible
that it may be so. In any case I do not think that they can
be looked upon merely as secretions, for in L. apicalis, as I shall
show presently, they retain the power of independent growth
long after the commencement of silica-deposition around them.
I am inclined rather to compare them with the plastids found
in many vegetable cells, in connection with which various sub-
stances, such as chlorophyll and starch, are deposited by the
protoplasm. Such plastids are living bodies, capable of growth
and multiplication, but they always seem to remain within their
parent cells. The histological conditions in the sponge are,
however, very different from what they are in plants, and it seems
almost certain that the protorhabds sometimes grow far beyond
the limits of any parent cell that there may be. It is the proto-
rhabd which, as we shall see later on, is responsible for growth
in length of the spicule ; and when we remember that some
spicules, such as those of the " glass-rope " in Hyalonema, or
the even more remarkable fixing spicule in Monorrhaphis, may
be considerably over a foot in length, it is evident that this struc-

THE president's ADDRESS. 237

ture must at any rate continue its activities independently of
any possible mother-cell, whatever may have been its origin.

The material at my disposal for the purposes of this inquiry
is naturally not well adapted to cytological investigation.
Nevertheless it has been possible to make some observations
in this direction. In LatruncuUa bocagei I have repeatedly
found certain small cells associated with the protorhabds, or
with the immediately subsequent stages of development, in a
very definite manner. In the youngest stage observed (fig. 1)
there is already a distinct indication of such cells forming a ring
around the protorhabd not far from the middle of its length.
In the specimens represented in figs. 2 and 3 two such rings of
cells are clearly visible, one a little above the middle of the
spicule and the other about half-way between this and the apical
extremity. It seems safe to conclude, from what happens after-
wards, that there are normally three cells in each of these rings.
I propose to term them the formative cells, for it is evident that
they have much to do with determining the manner in which
the silica is deposited. What their origin may be I am quite
unable to decide, but there seem to be two possibilities. Either
they are products of the division of an original mother-cell be-
longing to the protorhabd, or they are of extraneous origin and
have become associated with the developing spicule secondarily.
It seems probable that they continue to divide into daughter- cells
as development goes on, and fig. 7 shows faint indications of
what may be numerous minute formative cells arranged as a sort
of veil around the mature, or nearly mature, spicule.

A single much larger cell of a very different type is also com-
monly found associated with the developing spicule, both in
LatruncuUa bocagei, where it may be present together with the
formative cells, and in L. apicalis, where the formative cells have
not been observed, though there can be little doubt that they
are also really present. This cell is clearly shown in figs. 4, 7,
14, 15 and 18 (a.s.). It generally has the form of an oval, coarsely
granular body with a definite outline. One of the granules may
be a good deal larger than the others, and perhaps represents a
small nucleus. On the other hand, the entire body itself looks like
a very large nucleus, the cytoplasm belonging to which cannot

JouRN. Q. M. C, Series II.— No. 80. 18

238 THE president's address.

be differentiated from the surrounding mesogloea. In the
specimen shown in fig. 7, however, the appearances are some-
what different, the body being irregular, with a fairly distinct
nucleus in the middle, and seem to support the view that it is
an entire cell with which we are dealing.

The nature of this cell is somewhat problematical. Others
similar to it are found in the adjacent mesogloea, and I have by
no means always found one in immediate association with the
developing spicule. I venture to interpret it, provisionally at
any rate, in the light of my recently published observations on
the secretion of silica in the genus Collosclerophora,* of which
I gave an account to the Club last year. It will be remembered
that in that genus small masses of gelatinous silica are secreted
by certain scleroblasts (silicoblasts) not unlike the cells in ques-
tion. These masses of silica shrink up on dehydration and can
be made to swell out again by the addition of water. They do
not assume the definite form characteristic of ordinary spicules,
but are rounded, sausage-shaped or kidney-shaped bodies en-
closed in thin-walled vesicles formed either as precipitation
membranes or by condensation of the surrounding mesogloea.
I would suggest that the normal function of such cells is to bring
up supplies of silica to the developing spicules, where it is
utilised by the formative cells in building up the spicule around
the protorhabd, and that in Collosclerophora the protorhabd
and formative cells have disappeared, leaving the secondary
or accessory silicoblasts, as they may conveniently be termed,
to discharge their silica into the surrounding mesogloea in the
form of colloscleres. This hypothesis accords very well with
what is known of the disappearance of entire spicule-categories
in the phylogeny of many tetraxonid sponges, a subject to
which I referred at some length in my last Presidential
Address.

It would seem then, if these views are correct, that three
factors may be concerned in the growth of a siliceous sponge-
spicule : (1) the protorhabd, which is responsible for growth in
length and serves as a foundation upon which silica is de-
posited ; (2) the formative cells, which are responsible for the

♦ Proc. Royal Soc, B, vol. 89, p. 315, 1916.

THE president's ADDRESS. 239

arrangement of the silica, and (3) the accessory silicoblasts, which
supply the formative cells with the necessary material.

I may remark in passing that this hypothesis may help us
to reconcile the apparently conflicting observations of certain
authors who have dealt with this subject. Thus my friend Dr.
Woodland, in the last of his " Studies in Spicule Formation," *
contradicts the statements of Maas as to the development of the
anisochela in Esperella. Maas says that four nuclei occur in
connection with each spicule. Woodland says that there is
only one. They are dealing with distinct species, it is true, but
it is unlikely that there is any specific difference in this respect,
and it seems at least possible that Woodland has seen only the
large accessory silicoblast while Maas has seen the formative
cells. Similarly I am now inclined to interpret the single, large,
so-called " nucleus " figured by myself in connection with the
anisochela of Cladorhiza inversa,'\ as an accessory silicoblast rather
than as the nucleus of a mother-cell.

An analogy to the supposed behaviour of the accessory silico-
blasts is perhaps to be found in the activities of the " nurse-cells "
which I described in my memoir on the " Gametogenesis of
Grantia compressa.'^ | These cells collect food-material, in the
form of other cells, and convey it to the growing ova, just as the
accessory silicoblasts are supposed to collect silica and convey it
to the formative cells. The silica must, of course, be obtained
ultimately from the water flowing through the canal-system,
but how this is effected is entirely unknown. It seems probable
that an accessory silicoblast is only temporarily associated with
a developing spicule, and that, after parting with its load of
silica, it moves off again to some favourable locality where it
can collect a fresh supply.

After this somewhat lengthy and speculative digression we
may continue our account of the development of the discorhabds.
In the stage represented in fig. 2 {Latrunculia hocagei) the deposi-
tion of silica upon the protorhabd has already commenced, and
thickening has taken place especially at two points, viz. at

* Quarterly Journal of Microscopical Science, N.S., vol. 52.
t Report on the Challenger Monaxonida, Plate XXI. fig. 13.
X Quarterly Journal of Microscopical Science, N.S., vol. 60.

240 THE president's address.

one end (the future apex), where a distinct knob has made its
appearance, and at a point a little above the middle, surrounded
by the lower ring of formative cells. At the next stage (fig. 3)
the apical knob has grown larger, and a third thickening has
appeared in the middle of the upper ring of formative cells. A
little later a knob, the commencement of the manubrium, also
appears at the other end of the spicule, while each of the two
thickenings corresponding to the two rings of formative cells is
seen to consist of three conical projections arranged in a whorl,
and the entire shaft of the spicule between the knobs and whorls
has also become thickened, though to a less extent (fig. 6). I
have not been able to detect any formative cells in relation with
the terminal knobs, though I think it quite probable that such
may be present.

The coincidence of the positions of the median and subsidiary
whorls with those of the rings of formative cells suggests very
strongly that the latter are directly concerned in their develop-
ment, and the conviction that this is the case becomes irresistible
when we study the appearances represented in figs. 4 and 5,
Already in the earlier stages (figs. 2 and 3) it had become evident
that the formative cells constitute a kind of sheath, partially,
if not completely, enveloping the spicule. Around and between
the median and subsidiary thickenings this sheath is separated
from the spicule by a considerable interval. Presently it bulges
out around each of the two thickenings to form three pockets
(figs. 4 and 5) which no doubt correspond in position to the
three formative cells. It also becomes distended to a less ex-
tent between the thickenings and above and below them, and
this distention seems to take place only on one side of the shaft,
though this lop-sided appearance may possibly be due to post-
mortem changes.

I believe that the distention of the sheath is due to the
accumulation within it of a very watery solution of silica — or
possibly some silicate. In fig. 4 an accessory silicoblast is seen
lying between the two rings of formative cells, and it is sugges-
tive that it occurs on the same side as that on which the pockets
are beginning to form. In the walls of these pockets traces of
the formative cells can still be detected. I imagine that they

THE president's ADDRESS. 241

are taking up silica in solution from the accessory silicoblast
and passing it into the space between the sheath and the spicule.
The walls of the three pockets presently become highly refrin-
gent (fig. 5), suggesting that solid silica is deposited in them at
some distance from the shaft, to form knobs which become
connected with the shaft later on. These views are strongly
confirmed by the examination of corresponding stages in
Latrunculia apicalis (figs. 14, 15), although, as already stated,
the formative cells themselves have not yet been observed in
this species.

The development of the spicule up to this point is not, however,
exactly similar in the two species, but shows certain well-marked
differences which are of great interest from the point of view of
the vibratory theory. In accordance with this theory the
maximum deposition of silica takes place at the nodes or points
of rest of the vibrating rod. In Latrunculia apicalis three
thickenings usually appear simultaneously, one at each end and
one approximately in the middle (figs. 10-14). The two end
ones may appear before the middle one (fig. 9), though this seems
to be very rare, but I have never seen the middle one present
without the two end ones, and the two end ones are usually of
approximately equal size. In L. hocagei, on the other hand, one
of the terminal thickenings (the apical one) and the median
thickening both appear before the basal thickening (manubrium)
is recognisable at all (figs. 2 and 3), and it is a highly significant
fact that the median thickening is shifted quite distinctly towards
the apex — that is, towards the weighted end of the rod — which
Professor Nicholson tells me is exactly what would happen if this
thickening represented a nodal point.

In both species the subsidiary thickening now appears,
usually between the median and apical thickenings, but occa-
sionally, in L. apicalis at any rate, between the median thicken-
ing and the manubrium (fig. 17). Now if these subsidiary thicken-
ings also represent nodes there should be two of them, one on
each side of the median thickening, and we have to account
for the fact that there is only one. The solution of this diffi-
culty becomes obvious when we consider the arrangement of
the formative cells in L. hocagei. There should be altogether

242 THE president's address.

three nodes between the two ends of the rod, but there are only
two rings of formative cells, and apparently the nodal thickening
cannot take place in the absence of such a ring.

This brings us to another extremely interesting consideration.
It must be primarily the position of the rings of formative cells
that is determined by the vibrations of the rod, and only secon-
darily that of the local accumulations of silica which develop into
the whorls of the adult spicule. It would seem that we have
here a kind of tropism exhibited by the formative cells. Many
different kinds of such tropism, or taxis, are already recognised,
such as chemiotaxis, where the position of the cell results
from response to chemical stimulation; galvanotaxis, resulting
from response to electrical stimulation ; geotropism, resulting from
response to the stimulus of gravity, and so on. It seems only
reasonable, on the evidence before us, to suppose that the
formative cells are sensitive to vibrations in such a way that they
are induced to avoid the internodes and take up their positions
at the points of comparative rest of the vibrating rod, with
which they are doubtless at first in immediate contact.

We have noticed in describing the form of the adult disco-
rhabd in our two species that the chief specific distinction lies
in the fact that in Latrunculia hocagei (fig. 7) the apex is broadly
rounded and provided with a number of capitate spines, while
in L. apicalis (figs. 20, 21) it is drawn out into a long, slender,
tapering end-piece. This difference is obviously to be attributed
to the different behaviour of the protorhabd during development
in the two cases. In Latrunculia hocagei the protorhabd appears
to have finished its growth completely by the time that the
deposition of silica commences, so that first the apical and then
the basal extremity becomes completely enveloped. Growth in
length of the spicule as a whole is no longer possible except for
the very slight amount due to the thickening of the silica deposit
at each end. In L. apicalis, on the other hand, the protorhabd
continues to grow apically for a long time after all the thickenings
of the shaft have made their appearance. Apparently the original
apical thickening never completely envelops the end of the
protorhabd, which goes on elongating until it has become about
twice as long as it was when the deposition of silica first com-

THE president's ADDRESS. 243

menced. This forward growth is very clearly shown in fig. 16,
representing a stage in which the terminal portion of the
protorhabd projects quite freely beyond the apical knob. It is
noteworthy that the uncovered portion of the protorhabd was
deeply stained with borax -carmine, which had not been^ able
to penetrate through the silica coating lower down. The de-
position of silica follows the growth of the protorhabd, the final
result being the long, tapering end-piece of the adult spicule.

The later stages in the development of the whorls are not
easy to follow, owing to the difficulty of obtaining anything but
a side view. In both species the median and the subsidiary
whorl appear to consist normally of three segments, each
derived from one of the three knobs which constitute the whorl
in the young spicule. In the immature stages, however, there
appears to be a good deal of variation in the number of these
knobs, as w^ill be seen by references to the figures. This apparent
variation may be in part illusory and due to the concealment
of one of the knobs behind the shaft. It does not seem to be
entirely so, however, and it appears probable either that one or
more segments of a whorl may be suppressed or that they do
not necessarily all develop simultaneously. Such differences
must depend upon differences either in the number or in the
activity of the formative cells. How the knobs are transformed
into the flattened segments of the adult whorl, with their beauti-
fully crenate margins (fig. 24), is entirely unknown.

The apical whorl appears first as an equatorial ridge on the
apical knob (figs. 6, 16, 18). This grows out into a disk, also
with crenate margins (fig. 23) but not divided into segments.
The mechanism of this development is again quite unknown,
as also is that of the development of the various spines with
which the apex and the manubrium are ornamented, but I am
inclined to think that formative cells are again concerned as
architects in these later stages, and it seems not impossible that,
as already suggested, many formative cells may arise by divi-
sion of the original ones.

The foregoing account of my observations on Latrunculia,
though far from being complete, seems to justify the statement

244 THE president's address.

that the development of a siliceous sponge-spicule is a far more
complex process than is usually supposed, and that the course
of events is determined by a combination of physical and bio-
logical factors. The protorhabd, the formative cells and the
accessory silicoblasts all play their parts in bringing about the
final result. That result ajjpears to be primarily of a non-
adaptive, one might almost say accidental, character, and in
many cases the form of the spicule seems to remain entirely
without significance from the utilitarian point of view. Should
it happen to be useful for some particular purpose, however, the
sponge is not slow to make use of it, and in some mysterious
way arranges the spicules in the most suitable manner. In some
cases a useful form is no doubt fostered and improved under
the influence of natural selection, and that may be true of the
very remarkable discorhabds which we have been considering.
The perfect adaptation of the manubrium as an organ for the
fixation of the spicule in the fibrous cortex of the sponge certainly
suggests the operation of this factor, but it seems very impro-
bable that natural selection can have had anything to do with
the remarkable specific differences between the apices of these
spicules in Latrunculia hocagei and L. apicalis. Still less can
we suppose that natural selection is responsible for the difference
in the position of the median whorl in the two species, which
we have seen to be attributable to purely mechanical causes. In
short, we may, I think, conclude that the facts which I have
submitted for your consideration this evening afford consider-
able evidence in favour of the view that the characters by
which one species is separated from another are usually of little
or no importance to their possessor in the struggle for existence,
while adaptations are usually shared by many different species.

Description of Plates 15-17.

Figs. 1-7. Latrunculia bocagci Ridley and Dendy.

Fig. 1. Protorhabd, with whorl of formative cells (/.c.) near the
middle, x 1,900.
,, 2. Young spicule with two rings of formative cells (f.c.)
and apical and median thickenings commencing.
X 1,900.

JJ

J»

THE president's ADDRESS. 245

Fig. 3. Slightly later stage, showing commencement of sub-
sidiary thickening in the middle of the upper ring
of formative cells; sh. sheath, x 1,900.
,, 4. Later stage, showing commencement of manubrium (mn.),
formation of silica pockets by the formative cells,
and accessory silicoblast {a.s.). x 1,900.

5. Slightly later stage, with two distinct rings of silica
pockets {s.'p.). X 1,900.

6. Later stage, with the median (m.w.) and subsidiary

whorl {s.w.) represented each by three solid, conical
projections. X 1,050.
,, 7. Fully developed or nearly fully developed spicule, lying
in the mesogloea, with accessory silicoblast and
other cells ; a.w. apical whorl, other lettering as
before, x 1,050.

Figs. 8-24. LatruncuUa apicalis Kidley and Dendy.

„ 8. Protorhabd. X 1,050.

,, 9. Young spicule with basal (manubrium, mn.) and
apical (a.tv.) but no median thickening, x 1,050.
Figs. 10-13. Young spicules with basal, apical and median
thickenings (figs. 9-12 also show commencement, of
apical growth), x 1,050.
Fig. 14. Stage with well-developed basal and apical thicken-
ings and median whorl of three knobs (two only
visible) ; also showing the sheath (sh.) and an
accessory silicoblast (a.s.). The apical prolonga-
tion has been broken short, x 1,780.

,, 15. Stage in which the median (m.w.) and subsidiary
whorl {s.w.) are each represented by (probably)
three knobs of silica, which appear to have been
formed in silica pockets of the sheath (sh.). The
median whorl is displaced towards the manubrium
(mn.). An accessory silicoblast is present (a.s.).
X 1,780.

,, 16. Young spicule showing very clearly the apical growth
of the protorhabd (pr.), which projects freely beyond
the limit of the silica deposit and is also visible as an

246 THE president's address.

axial thread throughout the length of the shaft.
X 1,780.
Fig. 17. Young spicule with subsidiary whorl developed between
the median and basal whorls, instead of, as usual,
between the median and apical whorls, x 1,050.

,, 18. Stage in which the median and subsidiary whorls are
represented by rings of conical projections ; with
accessory silicoblast {a.s.). x 1,050.

,, 19. Stage showing the appearance of the second sub-
sidiary whorl (s.w. 2) on the apical prolongation;
other lettering as before, x 1,050.

,, 20. Fully developed or nearly fully developed spicule;
a.p., apical prolongation, other lettering as before.
X 1,050.

21. Fully developed spicule in which the chief subsidiary
whorl is missing, x 1,050.

22. Abnormal spicule with branch coming off from apical
, prolongation and chief subsidiary whorl imperfect.

X 1,050.

23. Apical whorl of a fully developed spicule, x 1,050.

24. Median whorl of a fully developed spicule, x 1,050.

)»

>j

Journ. Quekett Microscopical Club, Ser. 2, Vol. XIII., No. 80, Apnl 1917.

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2-47

THE DESMID FLORA OF DARTMOOR.

By G. T. Harris.

Communicated by J. Burton.

{Read March 27th, 1917.)

Plates 18, 19.

The Desmid flora of Dartmoor does not seem to have received
much attention if one may judge by the literature dealing with
it. E. Parfitt published a paper in the Transactions of the
Devonshire Association (1) on the Devon Freshwater Algae, in
which is given a list of the desmids then known to occur in the
county. In this list of eighty-five species only nine are definitely
stated to have been collected on Dartmoor, though it is probable
that many of the species in Mrs. Griffiths' collection were obtained
from Dartmoor localities. A. W. Bennett in the Journal of
the Royal Microscopical Society (2) published a list of the species
of Freshwater Algae collected by him in Hampshire and Devon-
shire in 1888 and 1889, the month being August in each year.
In this paper he gives a list of forty-six species and varieties of
desmids collected in the neighbourhood of Bovey Tracey and
Buckfastleigh, but what species were collected on Dartmoor
itself is not stated, merely a statement that the Dartmoor
gatherings were very poor "both in individuals and species."
Miss Joanna Town has published (3) a list of desmids collected
on Haytor Moor and Bovey Heathfield, but here again there
is no indication of the species actually collected on the moor.
In West's Monograph of the British Desmidiaceae (4) Dartmoor
habitats are specifically mentioned in only a few instances,
though the records for the county may possibly include Dart-
moor localities.

The section of Dartmoor dealt with in the present paper is
the great central portion comprised between Cawsand Beacon on
the northern extremity of the moor, and Believer Tor on the
southern, with Metherall as its eastern boundary and Lydford
as its western. This area is roughly a square of some one

248 G. T. HARRIS ON THE

hundred and forty-four square miles of unclaimed more or less
trackless moorland, broken with the principal tors for which
Dartmoor is famed, and which rise to just above 2,000 feet in
the northern portion. The whole surface is rolling and hilly,
and the district dealt with here is practically an elevated plateau
of about 1,100 feet altitude, from which rise the numerous hills
and tors to a height totalling from 1,600 to 2,040 feet. The
entire district forms the principal catchment area of the Devon-
shire water supply, and is covered with innumerable bogs and
rivulets which feed the rivers Dart, Teign, Tavy, Taw and
Okement, all of which have their head- waters in the higher
portion around the desolate waste of Cranmere. The bogs vary
in size and depth, and range from one of about thirty by twenty
yards on the one hand to the dangerous and extensive areas
of Raybarrow Mire in the northern portion and Fox Tor Mire
in the southern. Generally speaking, the bogs are confined to
the elevated plateau from which the higher portions of Dart-
moor rise, or to the lower slopes of these eminences, while small
moor pools and deep peat gullies are to be found on the higher
portions. Vast deposits of peat resting on a granite floor char-
acterise the whole district, even to the highest points of the
moor, and as a consequence the streams and bogs after even
slight rain become flooded with peaty water.

In collecting over this area it was divided into five districts
for convenience in working, and these five constitute the divisions
used in the census table of species accompanying this paper.
It is obvious that in a district with so many individual bogs as
Dartmoor possesses, it would be impracticable to enumerate
the species of each bog separately, hence I have adopted the
plan of grouping the bogs into districts formed as naturally
as possible. The following short descriptions of the grouping
may be useful for reference, the numerals being those of the
districts in the table of species.

I. Metherall. — This is the name of a moorland farm on the
eastern fringe of the moor, standing near the South Teign river.
The bogs in the district are principally on the long slope of Water
Hill which rises to the south, and that portion of moorland
known as Chagford Common. Other bogs are situated on

DESMID FLORA OF DARTMOOR. 249

Assy combe Hill, yet others are on the eastern slope of Long
Kidge. On the northern side of the South Teign river the
bogs extend up the "slopes of Thornworthy Tor. All these bogs
drain into the South Teign river or its tributaries. The Metherall
district is bounded on the south by Water Hill, south-west by
Assycombe Hill, west by Long Ridge and north by Thornworthy
Tor, and forms a very natural basin. The average altitude of
the bogs is about 1,250 feet.

II. GiDLEiGH. — This district is bounded on the north by
Cawsand Beacon, on the south by Thornworthy and Kestor, on
the west by Watern Tor and on the south-west by White Horse
Hill. In it is situated one of the two principal bogs of the
moor, the well-known Raybarrow Mire. This bog streams down
the southern slope of Cawsand Beacon, past Kennon Hill and
Ruelake Pit until it reaches the Wallabrook on Gidleigh Common
near its junction with the North Teign river, altogether a dis-
tance of about three miles. More or less connected with this
vast bog are those on the slopes of Hound Tor to the north-west
and Watern Tor to the west. These important bogs drain into
the North Teign river and its tributary the Wallabrook, and
make it one of the best collecting districts on the moor. South
of the North Teign river are the bogs on Shovel Down which
drain Stanetor Hill. This district also forms a very natural
basin with its bogs averaging from 1,200 to 1,300 feet in altitude.

III. Lydford. — This district on the western side of Dartmoor
extends from Black Down on the fringe of the moor to the
central ridge composed of the Cranmere and Cut Hill eminences
where it joins with sections I and II. It is bounded on the
north by Great and Little Links Tors and Amicombe Hill and
extends to Nat Tor and Staindon Hill in the south. The bogs in
this district drain into the rivers Lyd and Tavy and their
tributaries. Compared with the other districts mentioned in
this paper the bogs here are of less extent and the collecting
altogether poorer. Their altitude ranges from about 900 feet
on Black Down to 1,250 on Ger Tor.

IV. Haytor. — This section was less thoroughly worked than
any of the others, owing chiefly to bad weather and limited time.
The bog^ examined were principally around Haytor, Rippon Tor

250

G. T. HARRIS ON THE

and Saddle Tor. Generally speaking, the bogs in this district
are of small extent, but the yield in species is remarkably good.
Here again the bogs are of an average altitude of from 1,200 to
1,300 feet.

V. PosTBRiDGE. — This, the southern limit of my collecting
district, joins No. 1 (Metherall) at Water Hill in the north and
extends to Believer Tor in the south. On the east it is bounded
by the huge rampart of Hamel Down, while Higher White, Lower
White and Longford Tors mark its western extension. At Cut
Hill, practically the centre of Dartmoor, the Postbridge district
joins districts I and III. The district is drained by the East
and West Dart and the small streams Cherrybrook, Lade and
the southern Wallabrook. At least two important bogs occur in
this district, Merripit and Broad Down, while another, Sousson's
Bottom, though of less extent has proved an excellent collecting
station. The whole district is thickly studded with bogs of
greater or lesser extent, and from a collector's point of view ranks
with the Gidleigh and Metherall districts as the best on the moor.

In district No. VI, Moor Pools, I have placed together the
small moor pools situated above the altitudes at which the bogs
occur, and which are completely isolated and not dependent for
their water supply on drainage surfaces. These pools are not
numerous on Dartmoor, and are of very small area (about thirty
feet diameter), nevertheless they afford good and interesting
collecting and I have thought it worth while to keep the results
separate. They are nearly all above the 1,800 feet contour
line and generally characterised by a profuse growth of
Sphagnum cuspidatum var. plumulosum. The following table
shows the result in species, varieties and " forms " of the various
districts :

Table I.

District.

ISpecies.

Varieties.

Forms.

TOTAL.

I. Methekall .

200

52

11

263

II. Gidleigh

194

39

18

' 251

III. Lydford

137

29

6

172

IV. Haytob

lOG

37

11

214

V. Postbridge .

199

47

16

262

VI. MooB Pools .

112

25

6

143

DESMIB FLORA OF DARTMOOR. 251

Some two hundred gatherings in all were made over the district
described and the method of collecting and preserving the
material has been described in a previous communication to the
Journal of the Quekett Microscopical Club (5). With
regard to those methods I may say that additional experience
with them has proved their general usefulness and reliability.
Material collected two years ago is still in a perfect state of pre-
servation and available for further examination. Dr. Rendle
has called attention to the value of copper salts for preserving
the colour of chlorophyll (6) and Jorgensen has given an explana-
tion of the chemical reactions involved (7). One rather striking
feature has been noticed in the stored material. When the
killing and fixing agent was first added to the gathering, and for
months afterwards, no sign of life appeared, but during the last
six or nine months micro-organisms have commenced to appear
in increasing numbers although the amount of killing fluid added
was sufficient to destroy life in all the aquatic larvae, Entomos-
traca, etc., present in the gathering. Richet has said that
micro-organisms can acquire immunity towards certain anti-
septics, which immunity can be transmitted. This would
explain why subsequent additions of the fixing agent have failed
to check the increase.

The material was collected during the months of July, August,
September and October in 1915 and 1916. These two years in
Devonshire were marked by long spells of dry and bright weather.
In 1915 during five weeks' collecting on Dartmoor in August
and September rain was experienced only for a few hours on
three days, the rest of the time being almost unclouded sun-
shine. In 1916 an equally dry and bright period was experienced
when collecting around Lydford in August. On this trip a
moor-pool under Fur Tor at an altitude of about 1,877 feet was
observed to have shrunk to such meagre dimensions that only a
few gallons of water remained in the peaty bottom. The great
heat experienced about that time had heated this residuum
until it was quite tepid, yet abundant aquatic life was living in
a congested state in it. Several individuals of Dytiscus mar-
ginalis, numerous species of Entomostraca and some sixty
species and varieties of desmids were collected from it. It has

252 G. T. HARRIS ON THE

been said that strong sunlight is inimical to the life of the Chloro-
phyceae (8) ; but the condition of this pool would hardly support
the statement, as a long spell of unclouded days had been experi-
enced. The Postbridge material was collected the latter part of
September and beginning of October 1916, and extremely advene
weather was experienced, the entire month spent there being
wet and windy and the bogs becoming so swollen and saturated
that it was almost impossible to get far into them. On this
account I do not consider that the enumeration of species, etc.,
under this district in the census table quite fairly represents
the richness of the locality. The rivers and mountain streams of
Dartmoor were passed over entirely, as the bogs and moor pools
were too numerous to permit of time being devoted to them.
A test examination of the Dart at Postbridge (where it is a swift
mountain stream) was, however, made and from a small gather-
ing some fifty species and varieties were obtained, all common
to the bogs situated higher up the river, from which they most
probably came in periods of flushed streams.

In connection with the dispersal of desmids I would refer to
the extent to which these plants are ingested by various forms
of aquatic life. Larvae seem frequently to ingest them, and
as I have noticed the desmid almost through the body of the
larva with its chloroplasts still apparently uninjured it would
seem that the secretions of the animal do not seriously affect the
vitality of the desmid. In one rotifer I counted two individuals
of Tetmemorus granulatus, two of Tetmcmorus Brehissonii var.
minor, two of Staurastrum functulatum and one of Staurastrum
dejectum. In one individual of a species of Euchlanis I counted
the following desmids : three individuals of Cosmarium Bre-
hissonii, two of Tetmemorus granulatus, one of Micrasterias denti-
culata, one of Tetmemorus Brehissonii^ one Euastrum ansatum,
one Cosmarium difficile, one Staurastrum functulatum, one
Cosmarium suhcrenatum and one of Tetmemorus Brehissonii var.
minor. In none of these as far as could be made out did there
appear to be any digestion of the chloroplasts proceeding. Pro-
fessor G. S. West suggests (9) that the armature of desmids has
been developed as a protection against aquatic enemies, and
while none of the species mentioned as having been ingested has

DESMID FLORA OF DARTMOOR. 253

the highly developed system of spines of the furcate Staurastra,
yet such a desmid as Micrasterias denticulata should be suffi-
ciently formidable to secure immunity from attack. Frequent
specimens of the larger desmids, more particularly of the genus
Euastrum, have occurred from the Dartmoor bogs which were
completely enveloped in hyaline cases. Such an one is figured
on Plate 18, fig. 6. For some time I looked upon these cases as-
being due to a secretion of mucus by the desmid itself, but as
the case was obviously a completely separate structure the
solution did not appear to be very satisfactory. I was fortunate
enough later to come across one of these hyaline cases containing
two desmids, a specimen of Cosmarium Brehissonii and a species
of Euastrum. It then occurred to me that the cases were
probably secreted around the desmid (or desmids) in its passage
through the alimentary canal of some aquatic animal owing to
its inability to digest it.

In the field each collection, however unimportant the habitat,
was kept separate and duly labelled. At home the various
collections were worked out as individual units and the results
entered in a field-book, so that it is possible to state exactly what
species each station yielded. The various stations were then
grouped under their respective districts. The result in species,
varieties and forms from individual bogs varies with the extent
and apparent age of the bog and shows some degree of con-
stancy. That is to say, unimportant stations yielded from 70
to 80 records, average-sized bogs 120 to 130, while from the
extensive and ancient bogs of the Raybarrow and Merripit type
230 records would be obtained. The total number of species,
varieties and " forms " entered in my field-book for the district
dealt with in this paper is considerably over four hundred ; but
as many species require careful re-examination, and as a con-
siderable number of the Staurastra cannot at present be satis-
factorily named, the total number given in the census table
has been reduced to about four hundred. Furthermore, the
material cannot yet be considered exhausted, as prolonged
examination would certainly result in many additions to the
list.

Zygospores are not infrequent in the Dartmoor gatherings.

JouRN. Q. M. C, Series II.— No. 80. 19

254 G. T. HARRIS ON THE

One of the most prolific gatherings was made at Postbridge the
second week in September from a small boggy ditch through
which a stream of water slowly passed. The gathering was
packed with zygospores of Staurastrum punctulatum Breb.,
both type and its variety Kjellmanni Wille. Other genera and
species were represented but not to the same extent. Professor
G. S. West has stated that the end of September and beginning
of October is the period most favourable to the production of
zygospores, and the frequency with which they occur in the
Postbridge gatherings confirms this statement. As the majority
of them have already been described and figured I have made
no specific mention of them, with the exceptions of the zygo-
spores of Cos7narium Brebissonii and Roya obtusa var. montana
West. These two zygospores have not been figured, though as
West in the monograph of The British Desmidiaceae gives a
reference to Archer (10) concerning the zygospore of Cosmarium
Brebissonii I infer that some description of this zygospore is
there given. It occurred in Haytor gatherings collected at the
end of June, and several have been noticed. As will be seen from
the figure (PI. 19, fig. 10), it is globose and furnished with very
short conical projections, and measures about 90 fx in diameter.
The zygospore of Roya obtusa var. mow^awa West (PI. 19, fig. 11)
is ellipsoid and smooth, with a measurement of 22 yu, x 15 /x.
Kirchner states that the zygospore of the type {Roya obtusa) is
globose and smooth.

W. and G. S. West have assigned a numerical standard indica-
tive of the relative richness of desmid areas (11), and judged by
it Dartmoor, with 280 species (certainly 300 when all are named)
and about ninety varieties, must rank as one of the richest desmid
areas of the British Isles. It is interesting in this connection
to refer to some records from other areas. The plankton of the
Irish lakes has a desmid census of 120 ; the Welsh lakes one of
113 ; the Scotch lakes one of 223 ; while the total Desmidiaceae
of the British phyto-plankton is given as 236 species and 68
varieties (11). In the Dartmoor desmid-flora are to be found
the following representatives of what W. and G. S. West con-
sider western types of British Desmids : Tetmemorus Brebissonii
var. minor ; Euastrum fictum (forma) ; E. validum ; Cosmarium

DESMID FLORA OF DARTMOOR.

255

hifunctatum ; C, Corrihense ; C. pseudopyramidatum var.
stenonotum ; C. quadrifarium ; G. suhquadrans ; C. tenue ;
C. tumidum ; C. venustum ; G. viride. The following desmids,
rare in even the richest areas, will be found recorded in the
census list given later : Netrium ohlongum var. cylindricum ;
Penium exiguum ; Glosterium Ulna ; Euastrum ventricosuum ;
E. fulchellum ; E. pinnatum ; Gosmarium connatum ; G.
decedens var. ; G. elegantissimum ; G. Nymmanianum ; G. par-
vulum ; G. pseudoconnatum ; G. suhundulatum ; Staurastrum
aculeatum ; St. furcatum ; St. inconspicuum ; St. lanceolatum ;
St. pileolatum. Some twenty species and varieties are now
recorded for England for the first time, and about two hundred
and fifty are new records for Devonshire. The following table
(Table II) shows the various genera represented on Dartmoor,
with the number of species, varieties and " forms " in each
genus and the percentage of British species (only) in each genus .

Table II.

Percentage

Genus.

Species.

Varieties.

Forms.

of British
Species.*

Gonatyzogon

4

1

80%

Spirotaenia

6

40%

Mesotaenium

3

30%

Cylindrocystis

4

1

66%

Netrium

3

3

75%

Penium

18

3

3

64%

Roy a

2

1

66%

Glosterium

32

12

53%

Pleurotaenium

1

11%

Tetmemorus

4

2

100%

Euastrum

31

5

4

67%

Micrasterias

5

5

1

22%

Gosmarium

83

38

13

33%

Xanthidium

7

1

46%

Arthrodesmus

7

6

5

53%

Staurastrum

61

14

3

36%

Gosmocladium

1

■ Hi

Sphaerozosma

5

-^3 -u ^

Hyalotheca

2

Desmidium

2

^ 0 p

Gymnozyga

1

Ph Q3 (D

282

92

29

* Fractions of percentages omitted.

256 G. T. HARRIS ON THE

It will be seen from this table that several genera are very richly
represented in the district under review. Euastrum with 67
per cent, of the total British species is somewhat striking when
it is remembered that most of the species of this genus are among
the rarest of English desmids. All the species of the genus
Tetmemorus occur on the moor in profuse quantities, except
perhaps Tetmemorus minutus. The genera Spirotaenia and
Mesotaenium are certainly under-estimated owing to the diffi-
culty of correctly diagnosing species of these genera. On the
other hand the percentage of Cosmaria is very much lower than
one would have expected considering the large number of British
species. The genus Pleurotaenium is very poorly represented,
and Docidium not at all. In the genus Staurastrum the per-
centage given in the list is altogether too low for the number of
species actually occurring on the moor.

In connection with the obvious richness of Dartmoor as a
desmid area it will be of interest to refer to a theory recently
advocated in explanation of these prolific areas, viz. that " the
rich desmid areas correspond geographically with the Pre-
Cambrian and older Palaeozoic outcrops" (11). With respect
to the age of the Dartmoor rocks Clayden states (12) that " it
must not be forgotten that the moor [i.e. Dartmoor] has been a
land surface ever since its superincumbent volcanic peaks first
arose above the waves of the Devonian sea." Accepting this
view of the geologists it will be seen that Dartmoor lends distinct
support to the theory that the richest desmid areas are connected
with areas older than the Carboniferous. The granite tors of
Dartmoor rise high above the region in which the bogs abound,
so that the drainage water of the bogs is largely derived from the
older Palaeozoic formation which West considers essential in the
constitution of a rich desmid area.

While it cannot be said that any decidedly new species has
resulted from an examination of the Dartmoor bogs, several
" forms," and possibly some varieties, are of sufficient interest
to merit special mention. Professor G. S. West of Birmingham
University has been good enough to look over drawings of des-
mids from the material collected and to indicate those possessing
sufficient interest to make them worth reproducing. The figures

DESMID FLORA OF DARTMOOR. 257

in the plates accompanying this paper contain practically only
those indicated by him, and of these descriptive notes are given
when necessary under the heading " Description of Plates."
The nomenclature followed throughout in this paper is that
adopted by W. and G. S. West in their Monograph of the British
Desmidiaceae (4) as far as it is published. Unfortunately it
includes but a small portion of the genus Staurastrum, and for
the completion of the genus, and for genera such as Desmidium,
Sphaerozosma, etc., I have had to rely on Cooke's British Des-
mids (14) Kalfs's British Desmidieae (15) and whatever papers I
could procure supplementing these earlier works. It is for this
reason that the Staurastrum section of the census table must
be regarded as incomplete and more or less unsatisfactory. The
species in the census table have been arranged alphabetically
for convenience of reference.

It is my pleasing duty before closing this paper to acknow-
ledge my indebtedness to those who have so generously given me
assistance in its preparation. To Professor G. S. West, M.A.,
D.Sc, F.L.S., of Birmingham University, I am deeply indebted
for his kindness in going through my drawings and notes at a
period when he could ill spare the time, and sending me valuable
criticisms thereon. Several members of the Quekett Micro-
scopical Club have been extremely generous with their help :
Mr. C. Turner and Mr. J. Wilson have kindly and patiently gone
over gatherings of nearly all the principal bogs I have collected
from, sending me lists whereby I have corroborated and extended
my own ; to Mr. C. D. Soar, F.L.S., and Mr. D. J. Scourfield,
F.Z.S., and also to Mr. C. H. J. Sidwell, F.R.M.S., I owe thanks
for lending me literature connected with the group that has been
invaluable. Finally, I would ask The Quekett Microscopical
Club to accept my thanks for the kindness it shows me in accept -
ing this paper for the pages of its Journal.

Special Notes on Some Species

(5) Gonatozygon filosum Wolle. This rare species appears to
be confined on Dartmoor to the old and prolific bogs of
Metherall, Gidleigh and Postbridge. It rarely occurs.

258 G. T. HARRIS ON THE

(9) Spirotaenia minuta Thur. Only three British stations are

mentioned in West's Desmidiaceae for this desmid, one

of them being in Cornwall.
(8) Spirotaenia ehoracensis G. S. West. The only record hitherto

is Professor G. S. West's of Cam Fell, W. Yorkshire

{Teste, Professor G. S. West).

(11) Spirotaenia traheculata A. Br. (Teste, Professor G. S. West).

Lough Anna, Donegal, is the only British locality West
gives for this desmid. A few specimens were collected
from one of the Metherall bogs.

(12) Mesotaenium Be Greyi Turn. Although it is stated that

this species occurs, in common with most of the
Mesotaenia, in mucilaginous masses on rock surfaces,
it is met with on Dartmoor more or less free in the bogs.

(19) Cylindrocystis minutissima Turn. Lough Neagh. Ireland is
the only British locality given for this desmid in West's
Desmidiaceae. The Dartmoor specimens rather exceed
the measurements given by West, being 15 /x x 10 /x.

(23) Netrium interruptum var. sectum W. and G. S. West.
Hitherto only recorded from Westport, Co. Mayo.

(43) Penium navicula var. crassum W. and G. S. West, from
Postbridge, is a variety which has so far only been
recorded from the extreme north-west of Scotland
{Teste, Professor G. S. West).

(34) Penium exiguum West is another species hitherto only
recorded from the south-west of Scotland. It is widely
spread on Dartmoor but very infrequent.

(46) Penium spirostriolatum Barker. This interesting desmid is
generally distributed over Dartmoor and comparatively
plentiful in some of the larger bogs.

(74) Closterium incurvum Breb. This rare desmid was collected
at one or two stations on Dartmoor, but appears to be
more at home at a lower altitude, as I have collected
it in large quantities in some of the small ponds of
East Devon.

(58) Closterium acerosum (Schrank) Ehrenb. is another low-
land species rarely occurring on Dartmoor, but abundant
in the low-lying portions of the county.

DESMID FLORA OF DARTMOOR. 259

(83) Closterium Malinvernianum De Not. The single locality
for this species is, strictly speaking, not properly placed
by being included in the Dartmoor list. It was collected
from the perpendicular face of a dripping rock in Lydford
Gorge, which is situated on the extreme western fringe
of the moor. It is included, with Cosmarium speciosum
to be mentioned later, in the present list to record it
for the county, though as a matter of fact Lydford Gorge
is so nearly a part of Dartmoor (as Tavy Cleave is in the
same district) that any misrepresentation is not of a
serious nature.
(87) Closterium pusillum var. monoliihum Wittr. Typical G.
pusillum does not occur in the British Isles and the
varieties seem to be very rare. Gurnard's Head, Corn-
wall, is the only British station hitherto known for the
variety monoliihum.
(99) Tetmemorus Brebissonii var. minor De Bary. A northern
desmid judging by the recorded stations, but one fre-
quently found on Dartmoor.

(105) Euastrum affine Ralfs, forma scrobiculata Nordst {Teste,
Professor G. S. West) is new to Britain (vide British
Desmidiaceae, vol. ii. p. 18).

(114) Euastrum crassum var. scrobiculatum Lund. " A very
characteristic variety of rare occurrence " (West in
British Desmidiaceae).

(120) Euastrum dubium var. Snowdoniense (Turn.) West.
Turner, who originally described this as a species under
E. Snowdoniense, seems to have been the only one to
record it. It is certainly present in several of the older
Dartmoor bogs. West has now sunk it to varietal rank
under E. dubium.

(139) Euastrum validum W. and G. S. West has hitherto only
been recorded for the extreme north-west of Scotland.

(142) Euastrum Webbianum Turn. The diagnosis of this species
is somewhat doubtful.

(250) Cosmarium Ralfsii var. montanum Racib. is a desmid only
so far recorded from Carrautuohill, Co. Kerry. It is
not uncommon on Dartmoor.

260 G. T. HARRIS ON THE

(278) Cosmarium tenue Arch. In the British Isles this species
has only been recorded from Ireland. It is certainly-
rare on Dartmoor.

(213) Cosmarium moniliforme (Turp.) Ralfs. The type is quite
rare on Dartmoor, but the form panduriformis Heimerl
is extremely common.

(318) Staurastrum Bieneanum Rabenh. This desmid appears to
be quite local on Dartmoor, but was frequent in Merripit
bog. Typical specimens, however, were infrequent,
and tetragonal forms quite as plentiful as the normal
triangular.

(332) Staurastrum ellipticum West. Apparently confined to one
bog in the Lydford district. This was a bog of some
extent on the eastern slope of Hare Tor, above the
Rattlebrook ; here it was in some abundance.

(343) Staurastrum grande Bulnh. var. farvum West. Only one
or two specimens were observed of this desmid from the
extensive Merripit bog.

(380) Staurastrum striolatum (Nag.) Arch. Typical St. strio-
latum occurs generally on Dartmoor, but is very infre-
quent even in the bogs in which it occurs.

(329) Staurastrum dispar (Breb.). Teste, Professor G. S. West.
Roy seems to have been the only one to record this
species for English stations. It is somewhat frequent
on Dartmoor in the larger bogs.

(314) Staurastrum alternans var. fulchrum Wille. Teste, Pro-
fessor G. S. West. Apparently a northern variety
recorded by West from the north of Scotland.

(377) Staurastrum retusum Turn. var. horeale W. and G. S. West.
Teste, Professor G. S. West. This small species appears
to have been known hitherto only from the Orkney and
Shetland Islands. It is very rare on Dartmoor and
occurred only in two places at a considerable elevation.

(275) Cosmarium tatricum var. sphaeruliferum West. So far this
desmid has only been recorded from Co. Galway.

(192) Cosmarium jurcatosfcrmum W. and G. S. West. This
species, only recorded by West from the Orkneys and
Lough Neagh, occurs very sparingly in some of the

DESMID FLORA OF DARTMOOR. 261

Dartmoor bogs. For some time I confused it with C.
sphalerostichum Nordst. until a careful examination of
empty cells changed my opinion. Professor G. S. West
says of a drawing, " Probably C. furcatospermum.^^

(236) C. punctulatum var. granulusculum (Roy and Bissett)
West. The authors of the British Desmidiaceae state
that they have never seen any specimens of this variety.
I have had from Metherall and Postbridge gatherings
several empty cells which exactly agreed with the descrip-
tion and figure given from Roy and Bissett in West's
monograph, and it certainly seems an equally distinc-
tive variety with Klebs' C. functulatum var. rotundatum.

(162) Cosmarium bipunctatum var. subrectangularis West. A
Hebridean variety {Teste, Professor G. S. West).

(259) Cosmarium speciosum Lund. This species from Lydford

Gorge,

(260) and also its variety Rostafinshii have a doubtful claim to

be considered as Dartmoor desmids on account of their
habitats, but are included in order that they may be
recorded for the county. (See ante, Closterium Malin-
vernianum.)

(177) Cosmarium crenatum forma Boldtiana (Gutw.) West.
Apparently a very rare form only recorded by Roy and
Bissett from Scotland.

(291) Xanthidium armatum var. irregularis West. An Irish
variety which occurs very infrequently in several of the
older Dartmoor bogs.

(294) Xanthidium Robinsonianum Arch. This rare desmid
occurred in profusion in a small moor pool on White
Horse Hill at an altitude of about 1,800 feet. A few
specimens were also obtained from one of the bogs at
Postbridge.

Literature Cited and Consulted

1. Parfitt, E. : Devon Freshwater Algae. Transactions of

the-Devonshire Association, vol. xviii. 1886.

2. Bennett, A. W. : Freshwater Algae and Schizophyceae

262 G. T. HARRIS ON THE

of Hampshire and DevonsWre. Journal of the Royal
Microscopical Society. Feb. 1890.

3. Town, J. : Desmids found on Haytor Moor and Bovey

Heathfield. Torquay Nat. His. Soc.,yo\. ii., No. 2. 1916.

4. West, W. and G-. S. A Monograph of the British Desmidiaceae.

Vol. i. (1904); vol. ii. (1905); vol. iii. (1908); vol. iv.
(1912).

5. Harris, G. T. : The Collection and Preservation of the

Desmidiaceae. Journ. Q.M.G., 2nd Ser. vol xiii., p. 15.

6. Rendle, a. B. : Preservation of Natural Colour in Plants.

Nature, vol. xcviii., No. 2454.

7. JoRGENSEN, J. : Preservation of Natural Colour in Plants.

Nature, vol. xcviii., No. 2456.

8. Griffiths, B. M. : The Algae of Stanklin Pool. Birmingham

Natural History Society, vol. xii., No. 5.

9. West, G. S. : Variation in the Desmidiaceae. Journal

Linnean Soc. Botany, vol. xxvii. 1899.

10. Archer, W. : Quart. Journal Micr. Science, xiii., 1872, p. 100.

11. West, W. and G. S. : British Freshwater phyto-plankton,

etc. Proceedings Royal Society, B. vol. Ixxxi. 1909.

12. Clayden, a. W. : The History of Devonshire Scenery. 1906.

13. West, G. S. : Algae, vol. i. 1916.

14. CooKE, M. C. : British Desmids. 1887. ^

15. Ralfs, J. : The British Desmidieae. 1848.

16. Archer, W. : Article Desmidieae in Pritchard's History of

the Infusoria. Ed. 4. 1861.

17. West, W. and G. S. : Freshwater Algae from the Orkneys

and Shetlands. Transactions of the Botanical Society of
Edinburgh. Nov. 1904.

Description of Plates.

Plate 18.

Fig. 1. Euastrum oblongum (Grev.) Ralfs, forma nov. This new
form from Metherall bog has the apices of the polar
lobe truncate and not convex ; the lateral lobes are
more retuse than in the type, x 300.

Journ, Q.M.G.

Sep Z. Vol. XIII, PI 18

£^o)°.V v^* 'A^^

3.

10.

8.

9,

GT.Harria ieLaLdnat Adlard & Son SoWest, "Np-vfrmanL.tl.

Desniirl Flora of DartmooT'.

Journ.Q.M.C

Ser. 2,Vo].7JII P1.19.

1.

5.

6

8

G.T.HaxTis del.adTiat. Adlard & So-a-8<,West "Newman Lti.

Desmid Flora of Da.rtiaoor.

DESMID FLORA OF DARTMOOR. 263

Fig. 2. Euastrum (monstrosity) from Teignhead bog. The lower
semi-cell of this plant is typical Euastrum Didelta (Turp.)
Ralfs, while the upper semi-cell if not Euastrum humero-
sum Ralfs is a very close approximation, x 300.

3. Euastrum affine Ralfs, forma scrohiculata Nordst. See
note (105) p. 259. x 510.

4. Euastrum pictum Borg. forma, x 510.

5. Euastrum crassum (Breb.) Kutz. var. scrobiculatum
Lund.

6. Euastrum ohlongum (Grev.) Ralfs. Specimen in hyaline
case. X 300.

7. Euastrum hinale (Turp.) Ehrenb. forma secta Turner.
This form differs considerably in having the basal lobes
sub-quadrate and a deeper incision between the basal
and polar lobes, x 510.

8. Euastrum duhium Nag. var. nov. 27 //, x 18 /x. This
variety appears to be a much reduced form, with the
lobulation of the basal lobes less developed and the
conical granules of the polar lobe wanting, x 510.

9. Cosmarium suhquadratum Nordst. x 510.
10. Cosmarium formosulum Hofi. x 510.

>i

j>

J)

J)

Plate 19.

Fig. 1. Cosmarium ornatum Ralfs form, x 510.
,, 2. Cosmarium hipunctatum (Borg.) forma subrectangularis
West. The central papillae in most of the Dartmoor
specimens are larger than in typical C. hipunctatum and
divided transversely, so that they almost appear as
four. X 510.

3. Cosmarium lepidum West. var. x 510.

4. Cosmarium venustum (Breb.) Arch. " An unusual
form," Professor G. S. West, x 510.

5. Staurastrum Bieneanum Rabenh, form with markedly
retuse apices, x 510.

6. Arthrodesmus Incus Breb. var. Ralfsii West. Monstrous
form, with development of additional semi-cell. A

»»
))

J5

>)

264 G. T. HARRIS ON THE DESMID FLORA OF DARTMOOR.

vertical view of supernumerary semi-cell ; B, front view

of cell. X 510.
Fig. 7. Xanihidium Rohinsonianum Arch, forma, x 510.
,, 8. Staurastrum O'Mearii Arch, forma, x 510.
,, 9. Staurastrum retusum Turn. var. boreale W. and G. S.

West. X 510.
,, 10. Zygospore of Cosmarium Brebissonii Menegh. x 310.
,, 11. Zygospore of Roy a ohtusa var. montana W. and G. S.

West. X 510.

265

CENSUS OF DESMIDS FOUND ON DARTMOOR

V.O. = Very Common. 0. = Common.
P. = Frequent. R. = Eare. V.R. = Very Rare,

Relative frequency

in the district

described.

1

1

t

• 1-4

o

1

o

(0

to

.-2

§

P4

o
o
o.
(I
o
o

I

II

III

IV

V

VI

Order CONJUOATAE.

Family DESMIDIACEAE.

Sub-family Saccodeemae.

Genus Gonatozygon De Bary, 1856.

1. G. Br^bissonii De Bary

2. G. Brebissonii var. minutum W. and

0. S. West ....

3. G. Kinahani {Arch.) Rabenh.

4. G. monotaenium De Bary .

5. G. pilosum Wolle

R.

R.

F.

F.

V.R.

X

X

X
X

X
X
X
X

X
X
X

X
X

X

X
X
X

X

Genus Spirotaenia Breb. 1848.

6. S. acuta Hilse ....

7. S. condensata Breb,

8. S. eboracensis G. S. West .

9. S. minuta Thur.

10. S. parvula Arch.

11. S. trabeculata A. Br. .

V.R.

F.
V.R.

R.

R.
V.R.

X
X

X

X
X

X
X

X

X
X

X

X

X
X

X

X
X

Genus Mesotaenium Nag. 1849.

12. M. De Greyi Turn. .

13. M. macrococcum {Kiitz) Roy and

Bissett .....

14. M. Kramstai Lemm. .

R.

R.
R.

X
X

X

X

X

Genus Cylindrocystis Menegh. 1838.

15. C. Brebissonii Menegh.

16. C. Brebissonii var. minor W. and

0. S. West ....

17. C. erassa De Bary

18. C. diplospora Lund. .

19. C. minutissima Turn. (15/* x IOai)

C.

V.R.
C.
F.
R,

X

X
X

X

X
X
X

X

X
X
X
X

X

X
X

X

X
X

X

X

X
X

266

CENSUS OP DESMIDS FOUND ON DARTMOOR.

V.O. = Very Common.
P. = Frequent. R. = Rare.

C.= Common.
V.R. = Very Rare.

Genus Netrlum (Nag. 1849).

20. N. Digitus {Ehrenh.) Itziga. and

Rothe .....

21. N. Digitus var. constrictum W. and

O. S. West ....

22. N. inteTT\ipt\im{Breb.) Liitkem.

23. N. interruptum var. sectum W. and

O. S. West ....

24. N. oblongum {De Bary) LutJcem.

25. N. oblongum var. cylindricum W.

and O. S. West

Sub-family Placodermae.
Genus Penium Br6b. 1844.

cruciferum {De Bary) Wittr.

cuticulare W. and O. S. West

curtum Breb. .

curtum forma minuta West
{2l'25fMX 9'5fi)

cucurbitinum Biss.

cucurbitinum forma minor W
and Q. S. West

Cylindrus {Ehrenh.) Breb.

didymocarpum Lund.

exiguum West

exiguum forma major W. and
O. S. West

Libellula {Focke) Nordst.

Libellula var. interruptum W
and O. S. West

Libellula var. intermedium Roy
and Biss.

Mooreanum Arch. .

minutum {Raljs) Cleve

margaritaceum {Ehrenh.) Breb

Navicula Breb.

Navicula var. crassum W. and
O. S. West

polymorphum Perty

phymatospermum Nordst.

spirostriolatum Barker .

spinospermum Josh.

subtile W. and O. S. West

truncatum Brib.

Genus Roya. Wand O. S. West, 1896.
50. R. obtusa {Brib.) W. and O. S. West

26.

P.

27.

P.

28.

P.

29.

P.

30.

1

P.

31.

P.

32.

P.

33.

P.

34.

P.

35.

P.

36.

P.

37.

P.

38.

P.

39.

P.

40.

P.

41.

P.

42.

P.

43.

P.

44.

P.

45.

P.

46.

P.

47.

P.

48.

P.

49.

P.

<U 00 2

S 2 »

•43-Pn3

•S.9

V.C.

F.
F.

V.R.
V.C.

F.

F.
C.
R.

V.R.
F.

R.
F.
F.
R.

V.R.
F.

F.

R.
V.R.
F.
R.
C.

V.R.

R.
V.R.

F.

R.
V.R.

R.

R.

u

si
-to

0)

Si

X
X

X
X

X

X

X
X
X

X

X
X
X

X

X
X
X

X

n

X

X

X

X
X

X

X

X
X
X

X
X
X

X

o

III

X
X

X
X

X

X
X
X
X

X

X

X
X
X

X

X

u
o

w

IV

X

X

X
X

X

X
X
X

X
X

X
X
X

X
X
X
X

be
o

X
X

X
X
X

X
X

X
X
X
X

X

X
X
X

X
X

X
X

o

o
a,

o
o

VI

X
X

X
X

X
X

CENSUS OF DESMIDS FOUND ON DARTMOOR.

267

V.O. = Very Common. 0. = Common.
F. = Frequent. R. = Rare. V.R. = Very Rare.

Relative frequency

in the district

described.

1

■§

i

•—1

'6

u

Hi

u

o

w

<1>

•a

to

o
o

&

o
o

I

n

ni

IV

V

VI

51. R. obtusa var. montana W. and

0. S. West ....

R.

X

X

X

52. R. Pseudoclosterium (Roy) W. and

0. S. West ....

R.

X

X

X

X

Genus Closterium Nitzsch, 1817.

53. C. abruptum West

C.

X

X

X

X

X

X

54. C. abruptum var. brevius W. and

G. S. West ....

F.

X

X

X

X

X

X

55. C. acutum (Lyngh.) Breb,

F.

X

X

X

X

X

56. C. acutum var. linea W. and 0. S.

West .....

V.R.

X

57. C. aciculare Tuffen West

V.R.

X

X

58. C. acerosum {Schrank) Ehrenb.

V.R.

X

X

X

59. C. angustatum Kiitz. .

R.

X

X

X

60. C. Archerianum Cleve .

F.

X

X

X

X

X

61. C. attenuatum Ehrenb,

R.

X

X

X

62. C. Cornu Ehrenb.

R.

X

X

X

X

X

63. C. costatum Corda

C.

X

X

X

X

X

X

64. C. Cynthia De Not. .

R.

X

X

X

X

65. C. Dianae Ehrenb.

C.

X

X

X

X

X

66. C. Dianae var. arcuatum {Breb.)

Rabenh. .....

R.

X

X

X

67. C. didymotocum Corda

F.

X

X

X

X

X

68. C. Ehrenbergii Menegh.

F.

X

X

X

X

69. C. gracile Breb

R.

X

X

X

70. C. gracile var. tenue {Lemm.) W.

and G. S. West

F.

X

X

X

71. C. gracile var. elongatum W. and

G. S. West ....

V.R.

X

X

72. C. intermedium Ralfs

F.

X

X

X

X

X

73. C. intermedium var. hibernicum

West .....

V.R.

X

74. C. incurvum Breb.

R.

X

X

75. C. Jenneri Ralfs

C.

X

X

X

X

X

76. C. Jenneri var. robustum G. S. West

F.

X

X

X

X

77. C. juncidum Ralfs

C.

X

X

X

X

X

78. C. juncidiim var. brevier Roy

R.

X

X

79. C. Lunula {Mull.) Nitzsch .

C.

X

X

X

X

X

X

80. C. Lunula var. biconvexum

Schmidle ....

V.R.

X

X

81. C. lineatum Ehrenb. .

C.

X

X

X

X

X

82. C. parvulum Nag.

C.

X

X

X

X

X

X

83. C. Malinvernianum De Not.

V.R.

X

84. C. parvulum var. angustum W. and

G. S. West ....

V.R.

X

X

85. C. Pritchardianum Arch.

F.

X

X

X

X

X

86. C. pronum Breb. . . .

V.R.

X

268

CENSUS OF DESMIDS FOUND ON DARTMOOR.

ency
Let

•

Si

tS
u

tl

•

60

•i

3 til-!

l-i

o

o

*c

o

V.C. = Very Common. 0. = Common.

freq
dist
ribei

3

u-t

>>

0!

w

03

Q.
(-1
o
o

F. = Frequent. R. = Rare. V.R. = Very Rare.

Relative

in the

desc

S

O

M

(2

^

I

II

III

IV

V

VI

87. C. pusillum Hantzach var. mono-

lithum Wittr. ....

V.R.

X

88. C. rostratum Ehrerib. .

F.

X

X

X

X

X

89. C. Ralfsii Breb. var. hybridum

Rabenh. .....

V.R.

X

90. C. striolatum Ehrerib. .

V.C.

X

X

X

X

X

X

91. C. setaceum Ehrerib. .

V.R.

X

X

X

X

92. C. subulatum(iCwte.) Breb. .

V.R.

X

X

93. C. tumidum Johnson .

R.

X

X

X

X

94. C. toxon West ....

R.

X

X

X

X

X

95. C. Ulna Focke ....

V.R.

X

96. C. Venus Kiitz

R.

X

X

X

Genus Pleurotaenlum Nag. 1849.

97. P. Ehrenbergii (Bre6,) £>eSar2/

F.

X

X

X

X

X

X

Genus Tetmemorus Ralfs, 1844.

98. T. Br6bis3onii (Menegh.) Ralfs

C.

X

X

X

X

X

X

99. T. Brebissonii var. minor De Bary

F.

X

X

X

X

X

X

100. T. granulatus {Breb.) Ralfs

V.C.

X

X

X

X

X

X

101. T. granulatus var. attenuatus West

R.

X

X

X

X

X

102. T, laevis {Kiitz.) Ralfs

C.

X

X

X

X

X

103. T. minutus De Bary .

R.

X

X

X

X

X

Genus Euastrum Ehrenb. 1832.

104. E. affine Ralfs ....

F.

X

X

X

X

X

X

105. E. aflfine forma scrobiculata^ord*^*

V.R.

X

lOG. E. ampullaceum Ralfs

F.

X

X

X

X

X

X

107. E. ansatum Ralfs

V.C.

X

X

X

X

X

X

108. E. binale {Turp.) Ehrenb. .

V.C.

X

X

X

X

X

X

109. E. binale forma secta Turn.

C.

X

X

X

X

X

X

110. E. binale forma hians West

C.

X

X

X

X

X

X

111. E. binale forma Gutwinskii

Schmidle ....

C.

X

X

X

X

X

X

112. E. bidentatum Nag. .

F.

X

X

X

X

X

113. E. crassum {Breb.) Kiitz. .

C.

X

X

X

X

X

114. E. crassum var. scrobiculatum

Lund. .....

V.R.

X

115. E. crispulum {Nordst.) W. and

G. S. West ....

V.R.

X

116. E. cuneatum Jenner .

F.

X

X

X

X

117. E. denticulatum {Kirchn.) Qay .

F.

X

X

X

X

X

118. E. Didelta {Turp.) Ralfs .

V.C.

X

X

X

X

X

X

119. E. dubium Nag.

C.

X

X

X

X

X

X

120. E. dubium var. Snowdoniense

{Turn.) West.

R.

X

X

X

X

Vide PI. 18, fig. 3.

CENSUS OF DESMIDS FOUND ON DARTMOOR.

269

V.C. = Very Common. 0. = Common.

F. = Frequent. R. = Rare. V.R. = Very Rare.

121.
122.

123.
124.
125.
126.
127.
128.
129.
130.
131.
132.
133.
134.

135.
136.
137.
138.
139.
140.
141.
142.

E. elegans (Breb.) Kutz.

E. elegans var. Novae Semliae

Wille .
E. erosum Lund.
E. gemmatum Breb.
E. humerosum Ralfa
E. insigne Hass.
E. inerme {Ralfs) Lund.
E. insulare {Wittr.) Roy
E. montanum W. and G. S. West
E. oblongiim (Orev.) Ralfs
E. pinnatum Ralfs .
E. pulchellum Breb. .

pectinatiim Breb. .

pectinatum var. inevolutum
W. and G. S. West

pictum Borg. forma * .

rostratum Ralfs .
E. sinuosum Lenorm,
E. sublobatum Breb. .

validum W. and G. S. West

ventricosum Lund.

verrucosum Ehrenb.

Webbianum Turn, f

E.
E.

E.
E.

E.
E.
E.
E.

Genus Micrasterias Ag. 1827.

143. M. crenata Breb.

144. M. denticulata Breb. .

145. M. denticulata var. angulosa

{Hantzsch) W. and G. S. West

146. M. denticulata var, notata iVordsf.

147. M. Jenneri Ralfs var. simplex

West .....

148. M. oscitans Ralfs var. mucronata

(Dixon) Wille

149. M. papillifera Breb. .

150. M. papillifera var. glabra iVorcZs^

151. M. rotata (Grev.) Ralfs.

152. M. rotata forma evoluta Turn. .

153. M. truncata (Corda) Breb.

o

« <» So

c.

V.R.
V.R.
V.R.

R.

F.
V.R.

F.

F.

C.

R.
V.R.

C.

R.
V.R.

F.
V.R.
V.R.
V.R.

R.
V.R.
V.R.

V.R.
V.C.

R.
R.

V.R.

F.
F.
R.
V.C.
R.
F.

Genus Cosmarium Corda, 1834.

154. C. abbreviatum i?act6. forma minor

W. and G. S. West . . V.R.

155. C. annulatum (Nag.) De Bary . V.R.

156. C. amaenum Breb. . . . V.R.

* Vide PI. 18, fig. 4. f ^^'^^ p. 259.
JouRN. Q. M. C, Series II.— No. 80.

c3

a>

X

X
X
X
X
X

X
X
X

X
X

X
X

X

X
X
X
X

!S

II

X
X

X
X
X
X
X
X

X
X
X
X
X

X
X

X
X

X
X
X

13
u
o

in

X
X

X
X

X

X

X
X

X

u
o

c«

M

IV

X
X

X
X
X
X

X

X
X

X
X

X
X
X

0)

fcO

IS

'u

+3

to
o

p-l

X
X
X
X
X
X
X
X

X

X
X

o
o

u

o
o

VI

X
X

X
X

X
X
X

X
X
X

X
X

X

X
X

X

20

270

CENSUS OF DESMIDS FOUND ON DARTMOOR.

V.O. = Very Common. C. = Common.

F. = Frequent. R. = Rare. V.R. = Very Rare.

157. C. arctoum Nordst. var. tatricum

Racib. .....

158. C. bioculatum Breb. .

159. C. bioculatum forma depressa

Schaarschm. ....

160. C. bioculatum var. hiaus W, and

O. S. West ....

161. C. bipunctatum Borg.

162. C. bipunctatum forma subrect-

angularis West * .

163. C. Botrytis Menegh. .

164. C. Botrytis var. emarginatum

Hansg. .....

165. C. Brebissonii Menegh.

166. C. Blyttii Wille

167. C. Blyttii var. Novae Sylvae

W. and O. S. West

168. C. caelatum Ralfs

169. C. connatum Breb.

170. C. coarctatum West .

171. C. contractum Kirchn.

172. C. contractum var. ellipsoideum

{Elfv.) West ....

173. C. contractum var. ellipsoideum

forma retusa West .

174. C. contractum var. Gartanense

W. and Q. S. West

175. C. Corribense W. and Q. S. West .

176. C. crenatum Ralfs

177. C. crenatum forma Boldtiana

{Qutw.) West ....

178. C. Cucurbita Breb. .

179. C. Cucurbita var. attenuatum O. S.

Vf Cof « • • • •

180. C. Cuciirbita forma latior, W.and

G. S. West ....

181. C. Cucnmia {Cor da) Ralfs .

182. C. Cucumis var. magnum i?aci6. .

183. C. cymatonotophorum West

184. C. depressum [Ncig.) Lund.

185. C. depressum var. achondrum

{Boldt.) W. and O. S. West

186. C. difficile Liitkem.

187. C. difficile var. sublaeve Lutkem.

188. C. exiguum Arch.

189. C. exiguum var. pressum W. and

O. S. West ....

» Vide PI. 19, fig. 2.

Relative frequency

in the district

described.

.a

•

Ci5

u

>>
Hi

.

u
o

w

•

to

1

o
V

-1

o

&

o

1

I

n

in

IV

VI

V.R.

X

X

R.

X

V.R.

X

R.

X

X

X

X

F.

X

X

X

X

X

X

R.

X

X

X

F.

X

X

X

V.R,

X

V.C.

X

X

X

X

X

X

V.C.

X

X

X

X

X

F.

X

X

X

X

F.

X

X

X

X

X

R.

X

X

V.R.

X

X

R.

X

X

X

R.

X

R.

X

X

X

V.R.

X

X

X

V.R.

X

C.

X

X

X

X

X

X

R.

X

X

X

V.C.

X

X

X

X

X

X

V.R.

X

V.R.

X

R.

X

X

X

X

V.R.

X

X

X

V.R.

X

X

R.

X

X

X

X

F.

X

X

X

X

X

F.

X

X

X

X

X

X

R.

X

X

X

V.R.

X

V.R.

X

CENSUS OP DESMIDS FOUND ON DARTMOOR.

271

V

p. =

.0. — Very Common. 0. = Common.
Frequent. R. = Rare. V.R. = Very Rare.

Relative frequency

in the district

described.

3

a>

3

i,

o

03

w

•

1

o

01

o

u
o
o

I
X

II

III

IV

V

VI

190.

C. elegantissimum Lund. .

V.R.

X

X

191.

C. formosulum Hoff.

V.R.

X

192.

C. furcatospermum W. and 0. S.

West .....

R.

X

X

X

X

X

193.

C. galeritum Nordst. .

V.R.

X

194.

C. Garrolense Roy and Bias.

R.

X

X

X

X

195.

C. globosum Bulnh. .

R.

X

X

X

X

X

X

196.

C. globosum forma minor Boldt.
(12-5 X 10/i) ....

V.R.

X

197.

C. globosima var. minus Hansg.
(17 X Ufi) ....

V.R.

X

198.

C. goniodes W. and 0, S. West

V.R.

X

199.

C. Hammeri Reinsch. var. homa-
lodermum {Nordst.) West

V.R.

X

X

200.

C. Holmiense i^wnc?. var. integrum
Lund. .....

V.R.

X

X

201.

C. humile Nordst. var. substria-
tum Schmidle

V.R.

X

X

202.

C. humile var. glabrum Gutio.

V.R.

X

X

X

203.

C. impressulum Elfv.

F.

X

X

X

204.

C. inconspicuum W. and 0. S.
West .....

V.R.

X

205.

C. isthmochondrum Nordst.

V.R.

X

X

X

206.

C. laeve Rdbenh.

C.

X

X

X

X

X

X

207.

C. laeve var. octangularis {Wille)
W. and 0. S. West

V.R.

X

X

208.

C. laeve var. septentrionale Wille

R.

X

X

X

209.

C. Logiense Bissett .

V.R.

X

210.

C. lepidum West. var. nov.*

V.R.

X

211.

C. margaritiferum Menegh.

F.

X

X

X

X

X

212.

C. minimum W. and 0. S. West .

V.R.

X

213.

C. monilif orme (jTwrp.) i2a^/5

V.R.

X

X

X

214.

C. moniliform forma panduri-

formis Heimerl

C.

X

X

X

X

X

215.

C. Meneghinii Breb. .

R.

X

X

X

X

216.

C. nasutum Nordst. .

V.R.

X

217.

C. Norimbergense Reinsch.

V.R.

X

X

218.

C. Nymannianum Orun.

R.

X

X

219.

C. Novae Semliae Wille var. sibi-
ricum Boldt. ....

V.R.

X

X

220.

0. notabile Breb.

V.R.

X

221.

C. ochthodes Nordst.

F.

X

X

X

X

X

222.

C. ochthodes var, amoebum West

V.R.

X

X

223.

C. ornatum Ralfs

R.

X

X

X

X

224.

C. orthostichum Lund.

V.R.

X

225.

C. pachydermum Lund.

R.

X

X

X

226.

C. Palangula Breb.

V.R.

X

Vide PI. 19, fig. 3.

272

CENSUS OF DESMIDS FOUND ON DARTMOOR.

V.O. = Very Common. 0. = Common.

F. = Frequent. R. = Rare. V.R. = Very Rare.

227.
228.
229.

230.
231.
232.

233.
234.

C.
C.

c.

c.
c.
c.

c.
c.

235. C.
23G. C.

parvulum Br eh.

praemorsum Breb.

prominulum Racih. var. subun-
dulatum W. and O. S. West .

polygonum {Nag.) Arch.

Portianum Arch. .

Phaseolus Breb, forma minor
Boldt. .....

punctulatum Breb.

punctulatum var. subpunctu-
latum Borges ....

punctulatum var. rotundatum
Klebs .....

punctulatum var. granulus-
culum {Roy and Bissett) West

pusillum {Breb.) Arch. .

pseudopyramidatum Lund.

pseudopyramidatum var. steno-
notum Nordst.

pseudoconnatum Nordst.

pseudoexiguum Racib. .

pseudarctoum Nordst. .

pygmaeum Arch. .

pyramidatum Breb.

quadrimamillatum W. and G. S.

VY Cot • • • • •

Quadrum Lund. .

quadrifarium Lund.

quadratulum {Gay) De Toni .

Ralfsii Breb.

Ralf sii var. montanum Racib. .

reniforme {Ralfs) Arch. .

rectangulare Grun.

rectangulare var. cambrense
{Turn.) West.

Regnellii Wille

Regnesi Reinsch .

Rognesi var. tritum West

Rognesi var. montanum
Schmidle ....

sexangulare Lund. forma

minima Nordst.
, speciosum Lund. .
. speciosum var. Rostafinskii .
, sphalerostichum Nordst.
. Sportella Breb.
. Sportolla var. subnudum W.

and G. S. West
264. C. sphagnicolum W. and G. S. West

237.

C.

238.

C.

239.

C.

240.

]

c.

241.

c.

242.

c.

243.

c.

244.

c.

245.

c.

24G.

c.

247.

c.

248.

c.

249.

c.

250.

c.

251.

c.

252.

c.

253.

c.

254.

c.

255.

c.

256.

c.

257.

c.

258.

c.

259.

c.

260,

c.

261.

c.

262

c.

2 63

c

o

S 2 w

c.

V.R.

V.R.
V.R.
V.R.

V.R.
V.C.

C.

V.R.

V.R.
F.
C.

V.R.

F.

R.

R.
V.C.

R.

V.R.
V.R.
V.R.
V.C.

F.

F.

F.

R.

V.R.
V.R.
V.C.
V.R.

V.R.

V.R.
V.R.
V.R.
V.C.
F.

R.
R.

c!
u

.a
a>

X
X

X

X

X
X
X

X
X
X
X
X
X

X
X
X
X
X

X
X

X
X

X
X

o

II

X

X

X

X
X

X
X
X
X

X
X
X
X
X
X
X

X

X

o

III

X
X

X

X

X

X
X

X
X

X
X

X
X
X

X
X
X
X

X
X

l-l
o

IV

X

X

X

X
X

X

X

X
X
X
X
X

X

X
X

bo
l-l

03

o

X

X
X

X
X
X

X
X
X
X
X

X
X
X
X

X
X

X
X

m

"o
o

&

o
o

VI

X
X

X
X

X
X

CENSUS OF DESMIDS FOUND ON DARTMOOR.

273

V
F. =

.0. — Very ConiTnon. C. = Common.
Frequent. R. = Rare. V.R. = Very Rare.

Relative frequency

in the district

described.

o

•

u

o

w

a5

u
JD
-u

!/3
O

Oh
V
X

VI

.—1

o
o

o
o

I

II

III

IV

VI

265.

C. succisum West

V.R.

X

266.

C. subarctomn {Lagerh.) Racib.
forma punctata West

V.R.

X

266a

L.C. subarctoum (Lagerh.) Racib.
forma minor Nordst.

V.R.

X

267.

C. subcrenatxim Hantzsch .

C.

X

X

X

X

X

X

268.

C. subtumidum Nordst.

C.

X

X

X

X

X

269.

C. subtumidum var. Klebsii {Gutw.)
West .....

V.R.

X

270.

C. Subcucumis Schmidle

R.

X

X

X

X

X

271.

C. subprotumidum Nordst. var.
GregoTii {Roy and Biss.) West .

V.R.

X

272.

C. subundulatum Wille

R.

X

X

X

273.

C. subquadratum Nordst. .

R.

X

X

X

274.

C. subquadrana W. and G. S. West

R.

X

X

X

X

X

275.

C. tatricum Racib. var. sphaeruli-
ferum West ....

V.R.

X

X

276.

C. trachypleurumLwnd.var. minus
Racib. .....

V.R.

X

277.

C. Thwaitesii Ralfs .

R.

X

X

278.

C. tenue Arch. ....

V.R.

X

X

X

279.

C. tumidum Lund. .

V.R.

X

X

280.

C. tinctum Ralfs

C.

X

X

X

X

X

X

281.

C. trilobatum Reinsch

R.

X

282.

C. undulatum Corda .

V.R.

X

283.

C. undulatum var. minutum Wittr.
(21 X 18fi) ....

R.

X

284.

C. venustum {Breb.) Arch.

R.

X

X

X

X

X

285.

C. venustum var. majus Wittr.

V.R.

X

286.

C. viride {Corda) Josh.

V.R.

X

X

287.

C. viride forma minor West .

V.R.

X

Genus Xanthldium Ehrenb. 1837.

288.

X. aculeatum Ehrenb.

F.

X

X

X

289.

X. antilopaeum {Breb.) KiXtz.

F.

X

X

X

X

290.

X. armatum {Breb.) Rabenh.

C.

X

X

X

X

X

X

291.

X. armatum var. irregularius West

V.R.

X

X

X

292.

X. Brebissonii Ralfs .

V.R.

X

293.

X. cristatum Breb. .

V.R.

X

294.

X. Robinsonianum Arch. .

R.

X

X

X

X

295.

X. variable {Nordst.) W. and G. S.
West .....

V.R.

X

Genus Arthrodesmus Ehrenb. 1838.

296.

A. bifidus Breb. var. latidivergens

West .....

R.

X

X

X

297.

A. controversus W. and G. S. West

(12 X 12 X 6/xisth.).

F.

X

X

X

X

X

274

CENSUS OF DESMIDS FOUND ON DARTMOOR.

V.O. = Very Common.
F. = Frequent, E., = Rare.

C. = Common.
V.R. = Very Rare.

298. A. convergens Ehrenb.

299. A. Incua {Breb.) Hass.

300. A. Incus forma minor W. and

O. S. West ....

301. A. Incus var. indentatus W. and

G. S. West ....

302. A. Incus var. Ralfsii W. and O. S.

WW C'Sv • • • • •

303. A. Incus var. Ralfsii forma latius-

cula West ....

304. A. Incus var. subquadratus W.

and G. S. West

305. A. Incus var. indentatus forma

scrobiculata W. and G. S. West

306. A. octocornis Ehrenb.

307. A. tenuissimus Arch.

308. A. tenuissimus forma longispina

WW Gov • • • • •

309. A. triangularis Lagerh.

310. A. triangularis var. inflatus W.

and G. S. West

311. A. triangularis forma triquetra W.

and G. S. West

Genus Staurastrum Meyen, 1829.

312. S. aculeatum Men. .

313. S. alternans Breb.

314. S. alternans var. pulchrum Wille

315. S. apiculatum Breb. .

316. S. asperum Breb.

317. S. avicula Breb.

318. S. Bieneanum Rabenh.

319. S. Bieneanum var. ellipticuml^iVZe

320. S. brevispinum Breb.

321. S. brachiatum Ralfs .

322. S. Capitulum Breb. .

323. S. controversum Breb.

324. S. cristatum Nag.

325. S. cuspidatum Breb. .

326. S. cyrtocerum Breb. .

327. S. dilatatum Ehrenb.

328. S. dilatatum var. hibernicum W.

and G. S. West

329. S. dispar Breb

330. S. Dickeii Ralfs

331. S. dejectum Breb.

332. S. ellipticum West .

333. S. furcatum Ehr.

Relative frequency

in the district

described.

■*3

o

1-5

o

w

•

©

.'2

u
Si

to

to

•—4

§

&

o
o

I

II

III

IV

V

VI

V.R.

X

C.

X

X

X

X

X

X

F.

X

X

X

X

X

X

C.

X

X

X

X

X

X

V.R.

X

X

V.R.

X

V.R.

X

V.R.

X

F.

X

X

X

X

X

V.R.

X

X

V.R.

X

V.R.

X

V.R.

X

R.

X

X

X

X

X

X

F.

X

X

X

X

X

F.

X

X

X

X

X

V.R.

X

F.

X

X

X

X

X

F.

X

X

X

X

R.

X

X

V.R.

X

X

R.

X

X

X

F.

X

X

X

X

X

F.

X

X

X

X

X

V.R.

X

X

F.

X

X

X

X

V.R.

X

X

V.R.

X

F.

X

X

X

X

F.

X

X

X

V.R.

X

F.

X

X

X

X

X

V.R.

X

X

V.C.

X

X

X

X

X

X

V.R.

X

F.

X

X

X

CENSUS OF DESMIDS FOUND ON DARTMOOR.

275

V,0. = Very Common. 0. = Common.

F. = Frequent. R. = Rare. V.R, = Very Rare.

334.
335.
336.

337.

338.

339.
340.
341.
342.
343.
344.
345.
346.
347.
348.
349.
350.
351.
352.
353.
354.
355.
356.
357.
358.
359.

S.

S.

s.
s.
s.

s.

s.
s.
s.
s.
s.
s.
s.
s.
s.
s.
s.
s.
s.
s.
s.
s.
s.
s.
s.
s.

360. S

361.

S.

362.

s.

363.

s.

364.

s.

365.

s.

366.

s.

367.

s.

368.

s.

369.

s.

370.

s.

371.

s.

372.

s.

f urcatum var. candianum Dely.

furcigerum Breb. .

fiircigeruin var. reductum W.
and O. S. West

furcigerum forma armigerum
{Nordst.) O. S. West

f urcigerima forma eustephanum
{Nordst.) G. S. West

Griffithsianum (Nag.) Arch. .

glabrum (Kuiz.) Ralfs .

gracile Ralfs

granulosum {Ehrenh. ) Ralfs

gT&ndeBulnh. var. parvumT^es^

hirsutum Breb.

hystrix Ralfs

inconspicuum Nordst.

inflexum Breb.

lanceolatimi Arch.

laeve Ralfs ....

laevispimmi Biss. .

lunatum Ralfs

margaritaceima Meneg. .

O'Mearii Arch.

Meriani Reinsch

monticulosum Breb.

muricatima Breb. .

muticum Breb.

oUgocanthum Breb.

orbiculare Ralfs var. Ralf sii W.
and G. S. West

orbiculare var. depressum Roy
and Biss. ....

paradoxum Meyen

paradoxum var. longipes^orc^sf.

paxillifenma G. S. West

pilosellum W. and G. S. West

pileolatum Breb. .

polymorphum Breb.

punctulatum Breb.

punctulatum var. subproduc-
tima W. and G. S. West

punctulatum var. Kjellmanni

r r vtt& • • • • •

punctulatum var. pygmaeum
{Breb.) W. and G. S. West .

punctulatum var. striatum W.
and G. S. West

punctulatum forma minor W.
and G. S. West (20-22 ac x 15-1 Ifi)

Relative frequency

in the district

described.

'6

M

1

u
o

bo

'2

m
o

•o
o
a
(4

o
o

I

II

III

IV

V

VI

V.R.

X

F.

X

X

X

X

X

X

V.R.

X

R.

X

F.

X

X

X

V.R.

X

*

R.

X

X

X

F.

X

X

X

X

R.

X

X

X

V.R.

X

C.

X

X

X

X

X

X

V.R.

X

X

F.

X

X

X

X

V.R.

X

X

V.R.

X

X

X

V.R.

X

V.R.

X

V.R.

X

C.

X

X

X

X

X

X

V.R.

X

V.R.

X

X

V.R.

X

X

V.R.

X

R.

X

X

X

X

V.R.

X

V.C.

X

X

X

X

X

X

F.

X

X

X

X

X

X

F.

X

X

X

X

R.

X

X

V.R.

X

X

V.R.

X

X

V.R.

X

X

F.

X

X

X

X

V.C.

X

X

X

X

X

X

V.R.

X

C.

X

X

X

X

X

X

R.

X

X

V.R.

X

X

R.

X

X

276

CENSUS OF DESMIDS FOUND ON DARTMOOR.

V.O. = Very Common.
P. = Frequent. R. — Rare.

0. = Common.
V.R. = Very Rare.

373. S. proboscideum Breb.

374. S. Pringsheimii Reinsch

375. S. pterospermum Lund,

376. S. Reinschii Roy

377. S. retusum Turn. var. boreale W

and G. S. West

378. S. saxonicum Reinsch

379. S. sexcostatum Breb.

380. S. stTidlatum {Nag.) Arch

381. S. subcruciatum Cooke and Wills

382. S. BuhoThicnlaTe W. and G.S. West

383. S. teliferum Ralfs

384. S. tricorne Breb.

385. S. tumidum Breb,

386. S, turgescens De Not

387. S. vestitiira Ralfs

Genus Cosmocladium Breb. 1856.

388. C. constrictum {Arch.) Josh.

Genus Sphaerozosma Corda, 1835.

389. S. excavatum Ralfs .

390. S. filiforme {Ehrb.) Rabh. .

391. S. pygmaeum Rabh. .

392. S. vertebratiim Ralfs

393. S. pulchellum {Archer) Rabh.

Genus Hyalotheca Ehrenb. 1840.

394. H. dissiliena {Smith) Ralfs .

395. H. dissiliens var. minor {Mert.)

Ralfs .....

396. H. mucosa {Mert.) Ralfs

Genus Desmidium Agardh, 1824.

397. D. Swartzii {Ag.) Ralfs

398. D. cylindricum Grev.

Genus Gymnozyga Ehrenb. 1840.

399. G. moniliformis Ehrenb.

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Journ. Quckett Microscopical Club, Ser. 2, Vol. XIII., Ao. 80, April 1917.

277

TWO NEW SPECIES OF HYDRACARINA OR

WATER-MITES

Dartia Harris! gen. et sp. nov. and Eylais Wilsoni sp. nov.

By Chas. D. Soar, F.L.S., F.R.M.S.

{Read March 27th, 1917.)

Plates 20, 21.

While collecting Desmids on Dartmoor in August 1916, Mr.
G. T. Harris found several specimens of water- mites which he
submitted to me for identification. Amongst the specimens
were some from Broad Down Bog, near Postbridge, which proved
of more than common interest. These exhibited the following
noteworthy features : modification of second pair of legs,
absence of claws on fourth pair and swimming hairs entirely
wanting. There are several genera of Hydracarina in which
the claws above mentioned are absent, but they all possess the
swimming hairs. For the reception of this water-mite it is pro-
posed to create a new genus, and as the specimens were found
in the neighbourhood of the River Dart the name Dartia is
suggested. The only species of this genus at present known is
named after Mr. Harris — Dartia Harrisi.

Dartia gen. nov.

The body is oval in outline ; skin soft. The eyes wide apart
near margin of body. Legs without swimming hairs ; the fourth
pair of legs without claws. Epimera in four groups. Genital
area similar to that of Lebertia, but instead of the usual three
acetabula on each side of the genital cleft, there are four. The
palpi each have a long, stiff bristle on the flexor edge of the
second segment.

278 CHAS. D. SOAR ON

Dartia Harris! sp. nov.
Plate 20.

Specific Characters. — Body : about 0*74 mm. in length by about
0'71 mm. in breadth ; dorso- ventral dimensions 0"36 mm. A
slightly rounded oval in outline. The skin is soft, apparently
finely ridged, the ridges wide apart. The anterior part of the
dorsum has four longitudinal rows of gland-pores, each sur-
rounded by a strong chitinous ring and standing out prominently
like tubercles ; the posterior pair of the two inner rows lying
near centre of dorsum. Slightly posterior to these are a pair of
small plates and, a little wide apart, a pair of gland-pores similar
to the others. In centre of posterior part of dorsum is an ovate
porate chitinous plate with the apex directed posteriorly, and
on each side a gland-pore with strong chitinous ring. On the
edge of the body four or five similar pores occur on each side
(PL 20, fig. 1). The body colour is bright red, but all the
chitinous parts are a slaty blue.

Palpi. — Length about 0'33 mm. Second segment, proximal
half of extensor surface with two small spines, distal half with
three small spines, directed towards inner edge ; flexor surface
nearly straight with one moderately long straight bristle
pointing obliquely forwards. Third segment of nearly equal
width throughout, flexor surface concave, extensor surface
with one small spine placed midway and a short one near
the distal end; a moderately long bristle is placed on the
outer edge of the distal end of the flexor surface ; anterior
portion of segment hyaline, permitting the base of the fourth
segment to be seen at the articulation. Foiu'th segment
about half the diameter of the third, flexor surface with a
tubercle midway and a long curving hair springing therefrom ;
proximal half nearly straight, the distal half concave, with
three or four short fine hairs arising from minute papillae; the
margin at the distal end has two straight hairs, and another on
the extensor surface ; end of segment blunt. Fifth segment
compressed laterally, short, curved, ending in four or five claw-
like processes, (PI. 20, fig. 3) ; colour a slaty blue, extremity
with a tinge of orange.

Epimera. — First and second pairs very much like those of
Limnesia maculata, but with posterior margin rather more

TWO NEW SPECIES OF HYDRACARINA OR WATER-MITES 279

irregular. Third pair lying well up against the second pair and
fused with the fourth pair with a very indistinct line of demarca-
tion ; inner angle rounded, projecting well forward, the inner
margin weakly indented, extending obliquely outwards to the
rounded posterior margin (PI. 20, fig. 2).

Capitulum without rostrum, slightly cone-shaped anteriorly,
sides almost straight, parallel, posterior margin straight ; man-
dible 0*27 mm. in length, distal end weakly sinuate, the edge
turned towards the body distinctly serrate, proximal end clavate,
the intermediate portion moderately arched.

Legs. — First pair of legs about 0*53 mm. in length ; second
pair about 0'55 mm. ; third pair, 0'60 mm. ; fourth pair,
078 mm. The first segment of the first leg is very wide
and acetabular ; second segment with proximal flexor surface
slightly arched and with an oblique chitinous fold ; third, fourth
and fifth segments with proximal end contracted ; sixth segment
apparently devoid of hairs, claws very small and slender, distal
end thicker than proximal. The leg is rather sparingly supplied
with spines and bristles. First segment of second pair similar
to that of first pair but larger and broader ; the fifth segment is
rather more modified than usual, the proximal half of the flexor
surface bulging out very considerably, while the distal half is
concave. Sixth segment, distal end wider than proximal ; a
rather conspicuous feature here is the proximal end of this seg-
ment, which is bent nearly at right angles where it articulates
with the distal end of the fifth segment (PL 20, fig. 5) ; the claws
are similar to those of the first pair of legs, while the hairs, as in
the first pair, are not very numerous. Third pair of legs very
like the first pair, but each segment longer ; the claws are also
small and slender. Fourth pair : this pair requires more de-
tailed description. The extensor surface of the first segment
has two short spines on the distal half and another, longer, on
the distal margin ; the proximal portion of the second segment
is very much contracted, extensor surface with two short spines
and flexor surface with two moderately long ones at the distal
margin ; the distal end of third segment is much stouter than
the proximal, extensor surface has five spines and a shorter and
broader one at the distal end, the distal margin with four broad,
moderately long ones : fourth segment, extensor surface with
three pairs of spines, flexor surface with one very short spine in

280 CHAS. D. SOAR ON

proximal half, and three in distal half, distal end with three
pectinate spines ; fifth segment, extensor surface with two short
spines and three on distal margin, the flexor surface has about
five spines ; sixth segment, more slender than any of the other
segments, flexor surface with three or four small spines, without
claws, but with a long, fine terminal bristle at the base of which
there are one or two very short hairs.

The genital area lies for about half its length between the
fourth pair of epimera, at each end is a strong, curved chitinous
bridge for muscle attachments. There are two pairs of acetabula
on each side of the genital cleft, protected by a porate valve
or flap which is probably fringed with short hairs. The acetabula
are oval or elliptical in outline, each pair being united by means
of a chitinous band ; the proximal and distal margins are rounded
and the ends pointing inwards, tapered. This number of
acetabula in the genital area is rather uncommon, the more
usual number being three on each side of the cleft. Sex un-
known.

I wish here to acknowledge my indebtedness to Mr. William
Williamson, F.R.S.E., for his valuable assistance in determining
the characters of this water-mite.

Towards the end of May in the year 1914, I received from
Mr. J. Wilson, F.R.M.S., a small collection of water-mites taken
in the neighbourhood of Staines. Amongst them were four
specimens of the same species referable to the genus Eylais, but
the name of which I was unable to determine. The most impor-
tant characteristic for purposes of identification in the species
of this genus is the eye area. This I was quite unable to obtain
a good view of while the mite was alive, so I killed the four
specimens and left them in the glycerine solution sufficiently
long to remove the colour from the integument. When this
was nearly complete, I was then able to see the eye-capsule quite
distinctly and was surprised not to find any actual plate or
connection between the eyes, a feature which is found, so far as
the literature at present available shows, in all other known species
of this genus, now numbering over a hundred. I dissected the
area surrounding the eyes and made a camera drawing of
this in the case of three of the specimens ; the fourth specimen

TWO NEW SPECIES OP HYDRACARINA OR WATER-MITES. 281

was spoiled. The dissections were then mounted, two in
glycerine jelly and one in Canada balsam. On examination
of the mounted material it was seen, however, that the results
of the first examination were quite correct : — each eye-capsule
standing alone or separate on the body skin of the mite.
There was no visible connection, neither bridge nor chitinous
ridge such as has always been seen in the case of all species
of Eylais previously examined. In these circumstances I feel
bound to conclude that the water-mites Mr. Wilson sent me are
at present undescribed, and I propose therefore to do so,
giving this nova of the genus Eylais the name Wilsoni.

Eylais Wilsoni sp. nov.
Plate 21.

The four specimens received were females; about 3 '70 mm.
in length, rather a large size. Of the usual shape and colour
and in all respects, so far as external characters are con-
cerned, resembling when alive all other species of the genus.
The actual measurements of the body are about the same as
those of the type species E. extendens Miill., which it resembles
except in the eye area, where a difference is found. In
Eylais extendens Miill. the eye- capsules are connected by a
bridge of chitin, the anterior portion of which is about level
with the front edge of the capsule ; the posterior margin is also
deeply incurved. In E. Wilsoni, however, there is no connec-
tion whatever, the capsules being isolated on the integument.
The figures (PI. 21, fig. 1) show the position they occupy in
relation to each other. The width across the outside of the cap-
sule is about 0*4:8 mm., the length about 0"28 mm. The anterior
lens is set a little way in from the anterior margin, and the posterior
lens occupies about the same position as in the case of the type
species. Each capsule is more or less surrounded by a chitinous
projection from which on the anterior inner margin arise the
usual bristles.

The capitulum (PI. 21, fig. 2) including the pharynx is about
1 mm. in length, by about 0*74 mm. in breadth; the inside of
the oral area is about 0*12 mm. The air-sacs reach nearly to the
posterior margin of the pharynx; the anterior lateral processes
are long and wide; the pharynx projects beyond the posterior

282 CHAS. D. SOAR ON TWO NEW SPECIES OF HYDRACARINA.

lateral process about 0*16 mm. The air-sacs are broad and
straight when viewed from the front, but curve outwards towards
the outer margin of the pharynx. The figure (fig. 2) has been
drawn from a mounted specimen, so it is quite possible it appears
flatter than when in a living condition. The palpi are very like
those of the type species except that they appear to be more fully
provided with hairs (figs. 3 and 4). The segments (1-5) measure
as follows: 0*14 mm., 0*28 mm., 0*28 mm., 0*60 mm., 0*26 mm.
These measurements are taken on the outside, extensor margin.
The surface of the skin is strongly marked.

Descriptions of Plates.

Plate 20.
Dartia Harrisi gen. et sp. nov.

1. Dorsal surface.

2. Ventral surface, showing epimera and genital area.

3. Inner surface of right palp.

4. Genital area, showing relative position of anus.

5. Second leg ; articulation of fifth and sixth segments.

Plate 21.
Eylais Wilsoni sp. nov.

1. The eye and eye- capsules.

2. Capitulum.

3. Inner surface of right palp.

4. End of palp.

Journ. Quekett Microscopical Club, Ser. 2, Vol. XIII., No. 80, April 1917,

JOURN. Q.M.C.

Ser. 2, Vol. XIII., PL 20.

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JOURN. Q.M.C.

Ser. 2, Vol. XTII., PL 21

C D. Soar, delin. ad nat.

Eylais Wilsoni sp. nov.

283

NOTICES OF BOOKS.

Histology of Medicinal Plants. By William Mansfield,
A.M., Pliar.D. xii + 305 pages. 9x6 inches. 54 text
figures and 127 plates in the text. (New York : John Wiley
& Sons. [London : Chapman & Hall.] 1916. Price
125. 6d. net.)

This book is intended to provide a practical scientific course
in vegetable histology for the use of teachers and students.
Those colleges in which special attention is paid to the botany
of medicinal plants and practical work is carried out in the ex-
amination and diagnosis of powdered drugs of vegetable origin
will find it an admirable example of method. Part I contains
details of the microscope and instruction is given in the use
of the instrument as well as in the microscopical technique
required in the preparation and mounting of the material
to be examined. Part II deals with the general histology
of tissues, cells and cell contents, and here special atten-
tion has been paid to cell-inclusions such as starch grains,
aleurone grains and crystals, which are often of great use in
the diagnosis of fragmentary material. Part III is devoted to
the special histology of roots, rhizomes, stems, barks, woods,
flowers, fruits and seeds, the examples figured and described
being from plants officinal in the United States. This part is
very fully illustrated by 127 plates in the text from drawings
made by the author from actual specimens. These drawings,
ranging as they do over a very wide series of medicinal plants,
give the book a very distinctive character. The author claims
that the new classification of plant fibres and hairs which is intro-
duced into Part II will clear up much of the confusion that
students have experienced when studying these structures. The
book is essentially practical, but its use in Great Britain must be
limited by the fact that the material illustrated is chiefly drawn
from plants rarely coming under the notice of the student of
pharmacology.

284 NOTICES OP BOOKS.

Cambridge Botanical Handbooks : Algae, Vol. I. Myxo-
phyceae, Peridinieae, Bacillarieae, CUorophyceae, together
with a brief summary of the occurrence and distribution of
freshwater Algae. By Prof. G. L. West, M.A., D.Sc,
A.R.C.S., F.L.S., viii + 475 pages. 7 x lOJ inches. 271
text figures. (Cambridge : at the University Press, 1916.
Price 25s. net.)

The Cambridge Botanical Handbooks have been designed
to provide the student who desires to pursue his studies beyond
the limits of the general textbook with a series of volumes by
specialists on different groups of the vegetable kingdom. The
first of the series to appear is the above work dealing with certain
groups of the Algae ; other volumes of the series in an advanced
state of preparation are on Lichens, by Miss Lorrain Smith,
Fungi, by Dr. Helen Gwynne-Vaughan, and the Gnetales, by
Professor Pearson. Each volume will review from a broad
standpoint the results of recent research, more especially as
they affect the actual problems of evolution presented by the
various classes of plants with which it deals.

When Professor West's Treatise on British Freshwater Algae

was published in the Cambridge Biological Series some twelve

years ago, the student of this group of plants felt that now

indeed he had a guide through the labyrinth of conflicting views

and nomenclature that obscured the subject. And the worker

who admired the lucidity with which the complex details were

presented in that volume and its orderly arrangement will not

be disappointed on turning to this one. Since the publication of

the " Treatise " very considerable advances have been made in

our knowledge of many groups of Algae, and it is now proposed

to replace it by two works of which the volume under review is

one ; the other now in course of preparation will be a complete

systematic account with illustrations of the freshwater Algae

(with the exception of Desmids and Diatoms) which are known

to occur in the British Islands. The volume now published

contains a biological account of all the Algae included in

Myxophyceae, Peridinieae, Bacillarieae, Chlorophyceae, both

freshwater and marine, and therefore from a biological point of

view more than covers the Algae dealt with in the earlier work.

One turns very naturally perhaps to the chapter dealing with

NOTICES OF BOOKS. 285

the Peridinieae of whicli group no very compreliensive account
has hitherto appeared in any English textbook. It may even
be a surprise to some to find these interesting organisms dealt
with at all in a botanical treatise. Yet next to the Diatoms
they are the most important " producers " of organic substance
in the sea. Professor West claims them as true vegetable
organisms with holophytic nutrition. Indeed the distinction
between animal and vegetable organisms is so clearly stated in
this connection that we venture to quote it :

" The only sound basis for the discrimination between animal and
vegetable organisms is nutrition. It must be borne in mind that all
protoplasts, be they animal or vegetable, require practically the same
classes of food- substances, and, moreover, they assimilate them in pre-
cisely the same way. The vegetable protoplast has, however, acquired
the power of constructing its own organic food- substances. In con-
trast, therefore, to the animal protoplast, which requires its organic
food presented to it in an available and assimilable form, the vegetable
protoplast is capable of performing the preliminary synthetic work
of constructing complex food- substances from raw materials. This
constructive work is carried out in the normal plant by means of
chromatophores, and is dependent upon light, and hence the photo-
synthetic activity of the typical vegetable organism is its funda-
mental characteristic. The raw materials enter the protoplast in a
state of solution, and the elaborated materials which are the final
products of photosynthetic activity are from the beginning within the
protoplast ready for immediate assimilation whenever the action of
enzymes renders them thus available. Such nutrition is holophytic.

" The animal organism, on the other hand, has to take in from the
outside elaborated materials insoluble in water, and for the necessary
enzyme-action to work efficiently during the assimilation of these
substances they must be confined within a space which is more or less
limited. Consequently, the normal animal organism has had per-
force to adopt a method of ingestion of solid food- substances. This
type of nutrition is holozoic.^^

The author has devoted most of his investigations to the
study of the Green Algae ; the greater part of this work deals
with that group and embodies much original research. In a large
group containing so many diverse types (the number of known
species is probably 5,000) a comprehensive treatment such as
was adopted for the Myxophyceae or Peridinieae might have led
to confusion in the mind of the student. Hence we have the
orders of the Chlorophyceae treated in greater detail. The final

JouRN. Q. M. C, Series II.— No. 80. 21

286 NOTICES OF BOOKS.

chapter is devoted to the ecology of the freshwater Algae ; as this
subject is, however, still in its infancy any very satisfactory account
with our present knowledge is impossible ; but the results which
are given, based largely on the author's wide experience during
twenty years, are very interesting indeed, and this chapter will
well repay careful study. In fact, there is here almost an open
field for the student to increase our knowledge.

There are bibliographies to each group of Algae and an excel-
lent index; the illustrations in the text comprise 1,284 lettered
or numbered figures.

We congratulate the author on the completion of this valu-
able contribution to botanical literature and the Syndics of the
University Press on the appearance of the first of the " Hand-
books."

287

PROCEEDINGS

OF THE

QUEKETT MICROSCOPICAL CLUB.

At the 519th Ordinary Meeting of the Club, held on October 24th,
1916, the President, Prof. Arthur Dendy, D.Sc, F.R.S., in the
chair, the minutes of the meeting held on June 27th were read
and confirmed.

Messrs. Edward B. Stringer and Charles W. Penn were balloted
for and duly elected members of the Club ; eight names nominated
for election were read by the Hon. Secretary, who stated that the
Club was to be congratulated upon the number of new members it
was obtaining, notwithstanding the war.

The Hon. Secretary informed the meeting that Mr. J. M.
Offord, F.R.M.S., had presented the Club with six slides of various
microscopic writings and figures, the work of the late Dr. Farrant.
Mr. Offord had also brought a micro-slide portrait of Professor
Quekett, formerly President of the Royal Microscopical Society,
taken by Dr. Farrants, which was presented by Mr. Sidney H.
Tonks. A hearty vote of thanks was passed by the meeting to
Mr. Offord.

Mr. David Bryce then read the second (and final) part of a
paper, " On the Bdelloid Rotifera of South Africa," by Mr. W.
Milne, M.A., B.Sc. In introducing the paper, Mr. Bryce said all
would regret that Mr. Milne was unable to be present. It would
be remembered that on the occasion of his reading the first part
he had had an exceedingly trying experience in his journey from
Aberdeen. In consequence of the severe blizzard (March 28th),
the train had arrived in London nearly twelve hours late, and
Mr. Milne had no opportunity for rest, and had scarcely time for
a necessary meal before reading his paper to the meeting.

Mr. Bryce said that the paper contains descriptions of nineteen
new species, four new varieties, and one new genus. It is naturally
of considerable length, and the descriptions, consisting mainly of
technical particulars, are not suitable for reading in full detail.

288 PROCEEDINGS OF THE

He proposed, therefore, to mention briefly what seemed to be
the most striking characteristics of the various forms.

Mr. Bryce stated that he had only seen one of the species or
varieties now described, but he was pleased to note that since
his return to Scotland Mr. Milne had already found in Aberdeen-
shire three of the species which he had previously discovered in
Cape Colony. Mr. Bryce then briefly described various species of
the genera — Macrotrachela, Habrotrocha,Mniobia, Scepanotrocha,
Pleuretra, Otostephanos and Adineta.

In conclusion, Mr. Bryce stated that Mr. Milne hoped to furnish
as an appendix to this paper a list of all the Bdelloida he had
observed in South Africa. When this is prepared and the results
collated with the late James Murray's list of the species identified
and discovered by him in the same region, it may be expected that
the combined record of South African Bdelloida will be much
longer than can yet be shown for any other country in the world,
Great Britain alone excepted.

The President, in commenting on the paper, said they were all
greatly indebted to Mr. Bryce for the care and pains he had taken
in bringing it before them. He (the President) had had the
advantage of seeing the plates illustrating it, which were very
beautiful and added greatly to the interest. He thought, how-
ever, it would be more convenient if the measurements of micro-
scopic objects were given in the metric system, which has now
superseded the statement of size in fractions of the English inch.

A considerable amount of discussion ensued on this subject.
Mr. Bryce said he was quite in accord with the President in the
matter, and believed he was the first in this country to state the
measurement of Rotifera in microns.

The Chairman proposed a hearty vote of thanks to the author,
and to Mr. Bryce for reading the paper, which was unanimously
agreed to by all present.

At the 520th Ordinary Meeting of the Club, held on
November 28th, 1916, the President, Prof. Arthur Dendy, D.Sc,
F.R.S., in the chair, the miimtes of the meeting held on
October 24th, 1916, were read and confirmed.

Messrs. Joseph Fletcher, B.D., B.A., Charles Nicholson,
Leonard N. Hensman, C. W. Bushell, the Hon. Francis W. S.

QUEKETT MICROSCOPICAL CLUB. 289

McLaren, J. Gadsden, John Martin and Arthur S. Hill were
balloted for and duly elected members of the Club ; five nomina-
tion forms for membership were read.

A donation to the Club from the collection of the late Mr. R. T.
Lewis of a box of slides of Coccidae fromMr. J.M.OfTord, F.R.M.S.,
was announced. These had been mounted by Mr. Maskell, of New
Zealand, who was an authority on the group. The President said
when he was in New Zealand Mr. Maskell was alive, and these
appear to be his own mountings, and are probably type slides. A
hearty vote of thanks was accorded to the donor.

The President then requested Mr. D. J. Scourfield, F.Z.S., to
take the chair while he gave an account of " Gelatinous Sponge
Spicules." The address was illustrated by lantern-slides pro-
jected upon the screen. The President referred to the old saying
that " if you keep a thing for seven years you will find a use for
it." In the present instance he thought that the time was too
short, and the specimens he proposed to talk about had been kept
for more than three times seven years. When in Australia some
twenty-five years ago he had a large collection of material, and
had to go through it rapidly and compile a short catalogue.
Amongst other things, he found a sponge which contained peculiar
objects that looked like spicules and yet did not. They were
kidney- shaped, and were not bright, like ordinary spicules. He
was unable to identify them and laid them aside. Recently,
whilst working on sponges from the Indian Ocean, he came across
some which contained similar bodies. He had forgotten the pre-
vious discovery in Australia, but on looking through his notes
he found his original sketch. An old slide containing a rough
section had not been thrown away, and he was able to unearth
it. He took the section, which consisted almost entirely of
sand, unmounted it, and then investigated it by micro-chemical
methods. These enigmatical bodies were shown to be spicules
of a very unusual character. They consisted of hydrated silica,
although not identical in character with the usual siliceous spicules.
They were submitted to various tests, including immersion in
caustic potash and in hydrochloric acid, staining and examination
by means of the polariscope. It was found that they had the
peculiarity of swelling up when placed in water, which is a charac-
teristic not possessed by ordinary siliceous spicules. It was sug-
gested that in the living sponge they must occur as a jelly, but

290 PROCEEDINGS OF THE

in a mounting they become dehydrated and shrivelled. It was
remarkable that these specimens, which had been in balsam for
twenty years, still retained this capacity for absorbing water;
those from the Indian Ocean behaved in a similar manner.
The conclusion was arrived at that they consisted of silica in a
colloidal state and contained a larger proportion of water than
usual. The material was well preserved. There was no difficulty
in identifying the mother-cells by which the spicules were formed.
These are known as sclerohlasts. They have a small nucleus sus-
pended in the centre Avith granules close to the cell-wall. The
illustrations showed the gelatinous spicules, or colloscleres, de-
veloping on the exterior of the mother-cells, enclosed in vesicles
in the ground-substance of the sponge. A detailed account of
this discovery was published in the Proceedings of the Royal
Society for 1916, the new genus Collosclerophora being proposed
for the Australian species in which colloscleres occur.

The Chairman said we had had a very remarkable and interesting
communication from the President. The statement about the
preservation of drawings and material ought to be taken to heart
by everyone, as it is only by piecing together observations spread
over a series of years that many can arrive at the true results of
their work.

Messrs. Blood, Hilton and Dr. Rudd Leeson took part in a
discussion. At the Chairman's suggestion, a hearty vote of
thanks was accorded to the President for his interesting address,
who, after replying, resumed the chair.

Mr. N. E. Brown exhibited under a binocular microscope the
very beautiful white seeds of Anacam/pseros ruhens. He remarked
that really white seeds are very uncommon ; probably, with the
exception of a few of the beans, those present had very seldom
come across any. Plants of the genus Anacampseros came from
the drier parts of South Africa. There are two groups — one has
evident leaves, in the axils of which there is a tuft of hairs. These
hairs in some species are small and very much shorter than the
leaves ; in others they are more numerous and larger, and the
leaves, which are small, are partly concealed by the hairs. In
the other group the leaves are completely hidden by scales.
Examples of the latter group had been cultivated in a greenhouse
for many years in this country without it having been discovered
that they flowered at all. However, it was observed at last that

QUEKETT MICROSCOPICAL CLUB. 291

a seed capsule was thrusting through the top of the scales, which
at once gave evidence that the plant had been in flower. It was
then seen that the cause of the belief that the plants never
flowered was owing to the fact that, in addition to the in-
conspicuous nature of the flower, it only appeared during the
evening or night and endured but for a few hours. A number of
the seeds of A. rubens were brought for distribution among the
members. It was stated that in Rhodesia a decoction of the
plants was used as an intoxicant by the natives to such an
extent as to require Government intervention. Various speci-
mens of the plants, both dry and fresh, and seed capsules were
exhibited. An interesting discussion took place, and, in reply to
questions, Mr. Brown said that the plants were xerophytic, and
that probably cleistogamous flowers occurred among them.

Mr. J. Richardson, F.R.M.S., exhibited on one of the tables a
series of very beautiful photomicrographs of the genus Triceratium
among the Diatomaceae. The photos represented about 120
species, and were arranged on a number of card sheets, which
enabled them to be examined and the various forms compared with
great facility. They w^ere taken by Mr. Thomas Castle, of Heck-
mondwyke, and were greatly admired by those present.

Mr. S. C. Akehurst, F.R.M.S., exhibited and described a tank and
weed-holder for pond life to be used with low-power water-
immersion objectives. The tank is of metal, and is fitted into a
slide — fluid capacity 1 J oz. It can be adapted for use in conjunc-
tion with the base of a Rousselet live-box. It should be filled with
pond water to a suitable height and the immersion-objective
plunged into the water. Most free-swimming organisms being
photo tropic, they soon enter the field, and a fairly rapid examina-
tion can be made. For fixed forms on pond weed a holder with
universal movements has been provided. The apparatus would
be useful for searching large quantities of water for Plankton
forms.

Under a microscope on the table a slide of Pleodorina illinoisensis
was exhibited. This is an organism belonging to the Volvoceae,
and Mr. Scourfield, in calling attention to it, shortly described the
group, referring to the various members, Gonium, Pandorina,
Eudorina, Pleodorina, Platydorina and Volvox. He explained
that Pleodorina, which is found in many parts of the United
States of America, and has recently been taken in England,

292 PROCEEDINGS OF THE

consisted of a subspherical mucilaginous envelope with, spherical
cells in it, which closely resemble those of Eudorina. They
were remarkable because some of them (in the species shown,
four at the anterior end) are smaller and simply vegetative in
character, while the remainder are larger and reproductive ; in
Eudorina and its closer allies all are reproductive. Volvox and
its method of movement were also referred to and described.

The meeting closed with a hearty vote of thanks to the authors
of these various communications.

At the 521st Ordinary Meeting of the Club, held on January 23rd,
1917, the President, Prof. Arthur Dendy, D.Sc, F.R.S., in the
chair, the minutes of the meeting held on November 28th, 1916,
were read and confirmed.

Messrs. John Kiell, Albert A. Stow, J. W. Flower, A.M.I.E.E.,
Charles S. Burt and Ronald Winter were balloted for and duly
elected members of the Club ; six nomination forms for election
were read by the Hon. Secretary.

A small wax medallion portrait of Dr. Quekett, after whom
the Club is named — a gift from a member — was exhibited. The
President read a list of the names of those who had been nominated
by the committee as officers for the year, and the members present
made nominations to fill the vacancies on the committee.

At the request of the President, Mr. David Bryce then read a
paper — " On the Collecting of Bdelloid and other Rotifera."
He said : " Since the first discovery of Rotifera by the illustrious
Antony van Leeuwenhoek, rather more than 200 years ago, these
most interesting creatures have captured the attention and
admiration of generations of microscopists, who have willingly
devoted much labour to their investigation. They have found in
them a remarkable diversity of form, allied with the most com-
plicated and specialised organs, an astounding variety and activity
of movement, and an infinity of devices for the capture of their
food." Apparently the first English naturalist to publish any
original observations on the Rotifera was Henry Baker, whose
name is familiar as being allotted to the well-known Brachionus
Bakeri. After Baker's time there does not appear to have been
any original work done by English observers till the middle of
the nineteenth century. Pritchard's Natural History of the
Animalcules^ published in 1834, and the same author's History of

QUEKETT MICROSCOPICAL CLUB. 293

the Infusoria, 1842, were little more than compilations, the latter
especially being largely based on Ehrenberg's magnum opus.
There was a short paper by Brightwell in 1848, followed by
Dalrymple and by Dobie in 1849, and in 1850 by Gosse. In 1886
Hudson and Gosse published their epoch-making Monograph
The Rotifera or Wheel Animalcules. This, with the long and
exceedingly useful lists since compiled by Mr. C. F. Rousselet, and
published from time to time in the Journal of the Royal Micro-
scopical Society, has given the fascinating study of the Rotifera
a great impetus in recent years.

Mr. Bryce then described the various habitats of the Bdelloid
Rotifera, to which he had devoted the greater part of his attention
for many years. The method of dealing with the material
obtained, in order to free the rotifers from foreign matter,
was described, and the necessary apparatus suitable for collecting
the free-swimming forms and those that are found on the bottom
of the pools they frequent.

The apparatus used by Mr. Bryce in collecting and examining
the specimens were exhibited on the table, and were explained by
him after the meeting. Several members asked questions on
different points, to which Mr. Bryce replied ; and the President,
after remarking on the interest and usefulness of the paper, pro-
posed a vote of thanks to its author, which was given heartily by
acclamation.

At the 522nd Ordinary Meeting, which was also the 51st Annual
Meeting, held on February 27th, 1917, the President, Prof. Arthur
Dendy, D.Sc, F.R.S., in the chair, the minutes of the meeting
held on January 23rd were read and confirmed.

Messrs. Alfred B. Rendle, D.Sc, F.R.S., Humphrey G. Billing-
hurst, Frederick W. Woodman, Ambrose H. John, John Wigels-
worth and the Rev. Thomas Read were balloted for and duly
elected members of the Club.

The special business of an annual meeting was then proceeded
with. The President asked Messrs. N. E. Brown and M. Blood
to act as scrutineers, and the ballot was taken for the election of
officers for the ensuing year, and to make good the vacancies on
the committee caused by the yearly retirement. The result was
announced later, the officers as nominated being elected, and four
members selected to complete the committee. The Hon. Secre-

294 PROCEEDINGS OF THE

tary read the annual report. This was considered very satisfactory.
There was a small increase in the membership, the resignations
had been but few, though the loss by death had been somewhat
more than usual, while the number elected was greater than in
the previous year. The attendance at the meetings was good, and
there was a satisfactory list of communications and exhibits.
The excursions had been well attended. The librarian reported
that the number ef books borrowed from the library showed no
diminution. The curator reported that a large number of valuable
micro-slides had been added to the Cabinet, which now contained
over 8,000 specimens. The treasurer's accounts and balance-sheet
showed that though the finances were somewhat affected by the
prevailing difficulties, they were in a perfectly sound condition.
The adoption of the reports and balance-sheet was duly moved
and carried.

Prof. Dendy then gave his presidential address. The title was
" The Chessman Spicule of the genus Latrunculia ; a study in the
origin of Specific Characters." He said : "It is very well known
that there are certain types of tetraxonid microscleres in which
the spicule consists of an elongated, rod-like axis with whorls of
outgrowths upon it. As a result of a study of some novel varieties
of this type it occurred to me that the position of these whorls
might correspond with that of the nodes in a vibrating rod, and
that thus the form of the spicule might be largely determined by
a well-known physical cause, the deposition of silica taking place
chiefly where the rod was in a state of rest. The stream of water
flowing through the canal system of the sponge seems to afford a
sufficient explanation of such vibration, for the spicules are em-
bedded in the very soft, gelatinous mesogloea in the immediate
neighbourhood of the canals. I was led to make a somewhat
elaborate study of the so-called ' chessman ' spicule in two species
of the genus Latrunculia, and the development of these proved
to be extraordinarily interesting. A good deal has been written
on the development of sponge spicules, and some of the published
accounts appear to be very contradictory. It would seem that
this development is by no means so simple an affair as is often
supposed, but is in reality a very complex process, the course of
which is determined partly by physical and partly by what may
be called biological factors."

The two species, Latrunculia bocagci and L. apicalis, were ob-

QUEKETT MICROSCOPICAL CLUB. 295

tained by the Challenger expedition at Kerguelen, and the adult
form of the curious " chessman " spicules was described in the
report by Mr. Ridley and Prof. Dendy. Recently Prof. Dendy,
when examining a large number of stained sections which had been
preserved, found an almost perfect series of developmental stages.
He suggested the name discorhabds for these spicules. The
fully-grown discorhabd of L. bocagei is about 0*07 mm. in length or
height, and really bears considerable resemblance to a chessman.

With the aid of diagrams the process of the formation of the
" chessman " spicules of Latrunculia was then described in detail.
It was pointed out that development was not identical in the two
species, and that certain well-marked differences were of great
interest from the point of view of the vibratory theory. Atten-
tion was called to the fact that while the spicule of L. bocagei
terminates with a structure resembling a crown, that of L.
aficalis has a slender projection at its apex ; this projection is
really the upper part of the protorhabd, the growth and elongation
of which continues after the deposition of silica has commenced
upon the shaft.

The President concluded by saying that his observations seemed
*' to justify the statement that the development of a siliceous
sponge spicule is a far more complex process than is usually sup-
posed, and that the course of events is determined by a combina-
tion of physical and biological factors. The result appears to be
primarily of a non-adaptive character, and in many cases the form
of the spicule seems to remain entirely without significance from
the utilitarian point of view. Should they happen to be useful for
some particular purpose, however, the sponge is not slow to make
use of them, and in some unknown way arranges them in the
most suitable manner." A useful form might also be fostered
and improved under the influence of natural selection, although
that can hardly be supposed to be responsible for the minute
differences in the form of the spicules in the species under con-
sideration.

" In short, I think we may conclude that the facts which I have
submitted afford evidence in favour of the view that the charac-
ters by which one species is distinguished from another are
usually of little or no importance to their possessor in the struggle
for existence, while adaptations are usually shared by many
different species."

296 PROCEEDINGS OF THE

Mr. D, J. Scourfield, in proposing a vote of thanks to the
President for his interesting and valuable address, said he would
like to express the great indebtedness the members felt for what
Prof. Dendy had done, as President, for the Club in recent years.
It had been a trying time, and he thought that often at great
inconvenience to himself the President had attended their
meetings. Everyone would feel particularly gratified that he
had been so kind as to consent to become one of their vice-presi-
dents. He had so interested them on the subject of sponges that
there was no question whatever that all thoroughly enjoyed
hearing him, the various addresses on the subject being especially
appreciated. Mr. Scourfield then requested the President to
allow the address he had given that evening to be printed in the
Journal.

Mr. A. E. Hilton said he should like to second the proposal.
Mr. Scourfield had expressed on behalf of the members their sense
of indebtedness to Prof. Dendy for the way he had acted as
President for the past five years, a record length of presidentship
in the Quekett Club. During the whole of the time he had
devoted himself with the utmost assiduity to the interests of them
all, and had given them a number of most interesting and sug-
gestive lectures.

The vote of thanks having been carried with acclamation, the
President in reply said he was grateful for the kind way they had
spoken of him. It had always been a great pleasure to be associ-
ated with the Club. He gave with pleasure his consent that his
paper should be printed in the Journal.

A vote of thanks to the auditors and scrutineers was proposed
and carried unanimously, a similar compliment being paid to the
officers and committee for their work on behalf of the Club
during the year. To this the Hon. Treasurer suitably replied.

The result of the ballot for the election of officers for the ensuing
year was as follows :

For PreMcnl . . A. B. Hendle, D.Sc, F.R.S.

I Prof. Arthur Dendy, D.Sc, F.R.S.
C. F. RoussELET, F.R.M.S.
D. J. Scourfield, F.Z.S., F.R.M.S.
David Bryce.
For Treasurer . . Frederick J. Perks.

QUEKETT MICROSCOPICAL CLUB.

297

For Secretary . . James Burton.

Foreign Secretary C. F. Kousselet, F.R.M.S.
Librarian . , S. C. Akehurst, F.R.M.S.
Curator. . . C. J. Sidwell, F.R.M.S.
Editor . . . A. W. Sheppard, F.Z.S., F.R.M.S.

'>

J)

J)

j>

For

Four Members of

Committee

(J. Wilson, F.R.M.S.

J. RuDD Leeson, M.D., F.R.M.S.

C. S. Todd.
U. M. Offord, F.R.M.S.

298

FIFTY-FIRST ANNUAL REPORT.

Your Committee in presenting their Report for the year ending
December 1916 scarcely need remind members that the Club
during the whole of the time has suffered from difficulties caused
by the state of affairs referred to in the Report for last year,
some of them in even an increased degree. The lighting of
the streets and the means of travelling have both been further
reduced, increasing the difficulty of attendance for those residing
at a distance. Though there has been a diminution in con-
sequence, the average number present at the Ordinary meetings
has been rather over fifty-five, and at the " Gossip " meetings
rather over fifty- two, with a total individual attendance of 1,226
for the whole year. Your Committee consider this very satis-
factory under the circumstances. During the year, thirty-one
new members have been elected ; this is more than in 1915, and
the number could have been increased by five had there been the
usual meeting for business in December. The resignations have
been eleven, a great reduction on the loss due to this cause during
the preceding year, when the number was twenty-five ; eleven
have been lost by death. The net result is an increase of nine,
with a total membership of 458.

Mr. Dunstall's death took place in January. His energy and
enthusiasm in the study of the Rotifera were well known, and
his absence is marked with regret, especially at the " Gossip "
meetings. Dr. Charters White, President in 1880-81, and in
early days a very active member, passed away in March. Mr.
C. Lees-Curties died in April. Mr. Enock, an Honorary Member,
was lost to us in May. Mr. R. T. Lewis, one of the best-known
members, who joined the Club in 1865, soon after its foundation,
and had been since 1866 Hon. Reporter, passed away after
a short illness in June. His familiar figure, his wonderfully
regular attendance during fifty years, his frequent contributions
to the Journal, and participation in discussions on the various
communications, made him one of the most valued and appreci-

FIFTY-FIRST ANNUAL REPORT. 299

ated members, and one whose place it will be difficult indeed to
fill. Obituary Notices of several of these will be found in the
Journal.
The papers and notes communicated have been as follows :

Papers and Notes during the Year 1916.

January 2Wh. — Mr. G. T. Harris : On the Collection and Preserva-
tion of Desmids.
February 22nd. — Exhibition of Micro-objects by Mr. W. E.

Watson Baker, with short explanation of the chief examples.
February 22nd. — The Presidential Address : Some Factors of

Evolution in Sponges.
March 25th.— Mv. W. Milne, M.A., B.Sc. : On the Bdelloid

Rotifera of South Africa.
April 25th. — Mr. Chapman Jones : On the Secondaries or Dotted

Structure in the Pinnulariae.
April 25th. — Mr. A. A. C. Eliot Merlin : Nitzschia singalensis as a

Test-object for the Highest Powers.
April 25th. — The President : On the Spicular Structure of the

Sponge Geodia japonica.
May 23rd. — Photographs and Radiographs of Foraminifera,

with explanatory remarks by Mr. E. Heron-Allen, President

R.M.S. ; and Mr. J. E. Barnard, F.R.M.S., on A Method of

exhibiting the Internal Structure of Foraminifera by means

of X-rays.
June 21th. — Mr. W. Traviss exhibited and described a new

apparatus for collecting specimens in pond-work.
June 21th. — Mr. Wallis Kew : An Historical Account of the

Pseudo-scorpion Fauna of the British Isles.
June 27th. — Mr. A. E. Hilton : On the Sporangial Characters of the

Mycetozoa and the Factors which influence them.
October 2Uh. — Mr. David Bryce read Part II of Mr. W. Milne's

paper On the Bdelloid Rotifera of South Africa.
November 28th. — The President on Gelatinous Sponge Spicules.
November 28th.— Mr, S. C. Akehurst, F.R.M.S., exhibited and

described a tank and weed-holder for use with low-power

objectives.
November 28th. — Mr. N. E. Brown : On the Seeds of Anacampseros

rubens, and some Allied Plants from South Africa.

300 FIFTY-FIRST ANNUAL REPORT.

November 2^th. — Mr. D. J. Scourfield : On the Volvocaceae, with
reference particularly to a slide of Pleodorina illinoisensis,
exhibited by him.

Your Committee, on behalf of the Club, desires to thank the
authors of these communications. There have been no exhibits
of new apparatus by the opticians, their energies being almost
entirely taken up in meeting the demands of Government require-
ments.

The publication of the Journal, both the April and November
numbers, has been somewhat delayed — especially the latter ;
this has been chiefly due to difficulties arising from shortage
of labour at the printers, and our Hon. Editor deserves the
sympathy of members for the extra work and trouble it has
entailed.

The Committee would like to give some expression — in which
they are sure the members will join — to their sorrow at the serious
and long-continued illness of Mr. C. F. Rousselet, and to their
sympathy with him.

The Librarian reports that the number of books issued to
members during the year has been the same as last year, which is
encouraging, as 25 per cent, more were taken out during 1915
and 1916 than in the two preceding years 1913-14 ; an indication
that the members are showing an increasing interest in the Club's
valuable collection of books.

In addition to the twenty-eight books added during 1916,
there has been received from Mr. Rousselet a very interesting
series of photographs of drawings, and drawings of Rotifera.

These are being arranged for convenience of reference, and will
shortly be available for the use of members.

List of Periodical Publications Received for the Year

ENDING December 1916.

Academy of Natural Science, Philadelphia.
American Microscopical Society.
Birmingham Natural History Society.
British Association Report (Manchester, 1915).
Calijorniay University of.

FIFTY-FIRST ANNUAL REPORT. 301

Croydon Natural History Society.

Edinburgh Botanical Society.

Edinburgh Royal Botanical Gardens.

Geologists^ Association, Proceedings of.

Glasgow Natural History Society.

Hastings and East Sussex Naturalist.

Hertfordshire Natural History Society.

Illinois State Laboratory, Natural History.

Indian Museum, Calcutta.

Manchester Literary and Philosophical Society.

Micrology, Journal of.

Missouri Botanical Gardens, Annals of,

Northumberland, Durham, Newcastle-on-Tyne Natural History

Society.
Notarisia.

Nova Scotia Institute of Science.
Nyt Magazine.

Philippine Journal of Science. Sects. A, B, C, D.
Photomicrographic Society, Journal of.
Redia.

Royal Canadian Naturalist.
Royal Dublin Society, Proceedings of.
Royal Microscopical Society, Journal of.
Royal Photographic Society, Journal of.
Royal Society of London, Proceedings of. Series B.
Royal Society of New South Wales.
Smithsonian Institute, Annual Reports.
Tijdschrift.

Torquay Natural History Society, Journal of.
United States National Herbarium,
United States National Museum,
Victorian Naturalist,
Wisconsin Academy,

Books Purchased.

Kay Society : British Marine Annelids. Vol. III. Part II.

Plates. Prof. W. C. Mcintosh, M.A., LL.D., F.E.S.
Kay Society : Principles of Plant Teratology. Vol. I.

W. G. Worsdell, F.L.S.
JouRN. Q. M. C, Series II.— No. 80. 22

302 FIFTY-FIRST ANNUAL REPORT.

Ray Society : British Freshwater Rhizopoda and Heliozoa.

Vol. III. G. H. Wailes, F.L.S.
Cambridge Botanical Handbooks. Vol. I. Algae. Prof. G. S.

West, M.A., D.Sc.
Quarterly Journal of Microscopical Science.

The following books have been added to the Library during
the year ending December 1916 :
Presented by Henry Morland.
Index to the Localities named in Plates 1-288 of Schmidt's
Atlas der Diatomaceen-kunde.
Presented hy Alpheus Smith.
Elements of Entomology. W. S. Dallas.
Rambles of a Naturalist. 2 Vols. Quatrefages.
Q.M.C. Register for 1866-1876.

Presented hy the Author, Prof. Arthur Dendy, D.Sc.
Reports on Calcareous and Non-calcareous Sponges,

1915-16.
Report of Sponges in the Indian Ocean, 1913-16.

Presented hy the High Commissioner for *New Zealand.
Subantarctic Islands of New Zealand. 2 Vols. Edited by

Chas. Chilton.
Index Faunae Novae Zealandiae. Edited by F. AV. Hutton,
F.R.S.
Presented hy the Author, Charles Janet.
Note Preliminaire sur L'ceuf de Volvox ghhator. 1914.
L'alternance sporophyto-gametophytique de Generations
Chez les Algues. 1914.
Presented by the Author, George West.
Principles of Photomicrography.

Presented by the Author, Wm. Milne, M.A., B.Sc, F.R.S.E.
Various Papers on the Rotifera and Infusoria. 1883-1914.

Presented hy C. F. Rousselet.
Wild Fauna and Flora. Royal Botanical Gardens, Kew.
Transactions of the Middlesex Natural History Society. 1 Vol.

188&-92.
Northern Microscopist. 3 Vols. Vol. I., 1881 ; Vol. II.,
1882-3 ; Vol. III., 1884.
Collection of Photographs of Drawings, and Drawings of
Rotifers.

fifty-first annual report. 303

Portfolio containing Preserved Specimens of Ferns op
New Zealand.
American Microscopical Society'' s Journal. 2 Vols., 33 and
34, 1914, 1915.
Received in exchange.
Foraminifera of the North Pacific Ocean. Part V. 1915.
Cushman.
Presented by the Author, Henry Whitehead, B.Sc.
Notes on British Freshwater Leeches.
Presented by the Society.
Journal of the Photomicrographic Society. 2 Vols. 1915-16.

Excursion Secretary's Report.

During the year there were eleven excursions, all of which were
successful, the average attendance being 17*3 against 17'6 in
the previous year. Though no especially remarkable captures
were recorded, the outings were much enjoyed by all, and it was
felt that the social relaxation they afforded was of particular
value to the members in these anxious times. Hearty thanks
are due to Mr. Offord, who after conducting the Ealing excursion
invited the members to his house, where they were kindly enter-
tained at tea by Mrs. Oftord. At the Richmond Park Excursion
Mr. and Mrs. Wilson undertook a similar kind office, giving the
excursionists a welcome and tea at their house at Kew. It is
necessary also to express our indebtedness to the Royal Botanic
Society and to Sir Phillip Sassoon for the permission to visit
their private enclosures.

The Curator reports that during the past year the number
of slides borrowed has been well maintained, nearly 2,000 having
been lent. It has been a record year as regards additions
to the Cabinets, 448 slides having been added, 409 by presentation.
The principal of these have been over 100 very beautiful prepara-
tions of Diatomaceae and 60 various Botanical, from the collec-
tion of the late Mr. Dunstall. The sponge preparations placed at
the disposal of the Curator by the widow of the late Mr. Priest
have enabled the Club's collection of this group to be revised, and
many defective slides replaced, bringing up the total number to
165 preparations, many of great interest and beauty. Mr.

30i FIFTY-FIRST ANNUAL REPORT.

Rousselet has recently made a further donation of 26 slides to
his type collection of Rotifera, as well as three dozen other
miscellaneous preparations. The Club has a useful memento of
the late Mr. R. T. Lewis in the presentation of a collection of
31 slides of New Zealand Coccidiae, collected by Prof. Maskell.
Mr. Offord has also given half a dozen historically interesting
slides of microphotographs and micro -writings, done by the late
Dr. Farrants about sixty years ago.

The incorporation of new preparations into the Cabinets, and
the maintenance in good order of the existing slides, entail a
large amount of labour, and the Committee regret that greater
advantage is not taken of the Club's many valuable and interesting
preparations, especially by the older members, and of which they
evidently cannot be aware. The Curator will always be pleased
to give any information on the subject.

The Committee suggest that members able to do so should
bring their microscopes with some object for display to the
Ordinary meetings. At one time it was the custom, after the
regular business of the evening, for members to exhibit anything
of interest they might have. It is much to be wished that more
would make an effort to bring their instruments to the " Gossip "
meetings, and thus increase the general advantage and interest.
At present the number assisting in this way is in a minority.

The Committee as in previous years tenders its thanks to
Mr. Bestow for his continued and valuable help in the Curator's
department; and to Mr. Todd, who, as Assistant Librarian, has
been of the greatest service. Mr. L. C. Bennett throughout the
year has again given his efficient attention to welcoming visitors
and new^ly elected members, and deserves the gratitude of the
Committee and Club.

The Committee desires on behalf of the members to thank the
various officers for the careful supervision they have given to the
affairs of the Club during th^ very trying period which has been
passed through. They feel it essential that, while present condi-
tions remain, everyone should make an especial effort for the
welfare of the Club ; that it may, notwithstanding the untoward
circumstances, continue to exhibit the usefulness and success
which have characterised it in the past, and have continued to
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23

307

NOTE ON THE MEASUREMENT OF MAGNIFYING

POWERS.

By W. M. Bale, F.R.M.S.

{Read in Title October '2Srd, 1917.)

In this note, which, as will be apparent, is addressed mainly to
those who, like myself, are imskilled in the science of optics, it is
proposed to explain, somewhat more fully than is usual in the
textbooks, how to construct a table of magnifying powers ; and,
further, to set forth the simplest possible means of ascertaining
what power may be provided at any moment when, owing to
alteration of the tube-leng"th, the normal arrangement is departed
from. If opticians always stated, as they should do, the initial
magnification of each ocular and objective, it would only be
necessary to multiply the two together to get the power of the
combination, but neither this nor a complete table of powers
would meet the case of those who, like many of us, possess a
number of objectives and eye-pieces from a variety of makers.

Even if we have a completely fitted instrument with an accom-
panying list of magnifying powers, we must verify the latter, as
these lists are sometimes very incorrect ; indeed there are some
respecting which it can be seen at a glance that they cannot
possibly be correct. For whatever may be the powers of a series
of objectives with a given eye-piece, it is obvious that by substitut-
ing a higher eye-piece the powers of all the combinations must be
increased in the same ratio ; e.g. if we have three objectives
giving with an A eye-piece the respective powers of 50, 100 and
200, then if the B eye-piece increases the first power to 75, we
know that it must increase the others to 150 and 300, and if an
optician's list fails to maintain these ratios it must necessarily be
wrong. To quote a case in point — I recently examined a cheap
but good instrument with an accompanying table in which the
powers of a one-inch and a quarter-inch with the lowest ocular are

JouRN. Q. M. C, Series II.— No. 81. 24

308 W. M. BALE ON THE

stated as 40 and 80, and with a higher ocular as 156 and 415.
Obviously if the substitution of the higher eye-piece doubled the
power in the case of the one-inch, as stated, it would do likewise
in the case of the quarter, and assuming 156 to be correct with
the first eye-piece, the power with the higher would be 312, not
415. Actually, the powers of the four combinations, instead of
being 40, 80, 156, and 415, as stated, are approximately 43, 75,
188 and 327.

Broadly speaking, there is only one way of measuring the
magnifying power of a microscopical combination where the
separate powers of the constituents are unknown, namely, by
comparing the actual diameter of some object (usually the scale
of a stage micrometer) with the magnified image of the same.
This is most readily done by projecting the image of the micro-
meter-scale by means of some form of camera-lucida on to a paper
at a distance of ten inches and marking some of the divisions on
the paper, or even by projecting them on to a ruled scale, so that
comparison is easy ; e.g. if one-hundredth of an inch when magni-
fied equals one inch, the power is 100.

Thus far the textbooks ; but these directions leave room for a
certain amount of error owing to their ignoring the fact that in
all camera drawings the magnification is appreciably greater in
the marginal portions of the field than near the centre. If we
project the micrometer-scale across the field and mark ofi the
divisions, we naturall)^ select if possible so many divisions for
comparison as will coincide exactly with one or more divisions of
our rule, in order to avoid fractions ; and in one measurement
we may attain this end by utilising only the central part of the
field, while in another we may have to utilise nearly the whole.
The result obtained in the first case should be correct ; the other
will, with an eye-piece giving a large field, be 4 or 5 per cent,
too great.

The procedure which I adopt to ascertain the magnifying power
of a combination is as follows :

A. — Measure with the camera * the exact diameter (at 10 inches)
of the magnified field.

* A Bcale reflector is recommencled, as it is an appliance so easily
improvised if the microscope is not provided with one. The simplest
method is to take a piece of wire, wind it two or three times romid the
oye-piece, twist the two ends together to keep it firm, and then, keeping

MEASUREMENT OF MAGNIFYING POWERS. 309

B. — Measure with the stage micrometer tlie actual diameter
of the field.

Then A divided by B is the magnifying power.

It is to be noted, however, that the apparent diameter of the
field, as projected by the camera and measm'ed on the flat, is, for
the reason before stated, excessive, and a deduction must be
made, according to the rule to be stated farther on, to com-
pensate for the uneven magnification.

Example. — The apparent field-diameter, as measured on the
flat, is 5 inches, or 127 mm. We deduct 3 millimetres, making
the eft'ective diameter 124 mm. The actual diameter of the
field, as shown by the stage micrometer, is 0*62 mm. Then 124-i-
0*62 = 200, which is the magnifying power.

The diameter of the magnified field of view depends solely on
the eye-piece diaphragm ; it is therefore a constant quantity,
which when once measured may be recorded for future reference.
If preferred it may be scratched on the eye-piece tube.

As soon as all the eye-piece fields have been measured and
recorded there is no further need for the camera, or for any other
accessory than the stage micrometer ; the microscope is used in
its ordinary position, and the power of each eye- piece tested in
combination ^dth each objective till the table is completed. The
same simple process enables us to find at once what power we
are using at any time when, owing to variation of the tube-length,
our standard scale is not applicable ; a useful feature in these
days when the common use of such imperfect appliances as
fourths and sixths without cover-correction must, one would
think, lead to a continual pushing in and out of draw-tubes.

I may here note a few points which require attention when
making our measurements, if reasonable accuracy is to be
obtained. We must see that all draw-tubes are pushed home,
unless it is preferred that the magnifications should be taken
with a 10-inch tube-length, vv^hen the tube must be set accord-
ingly. The objective collar must be looked to, as its position
appreciably affects the power. I have found that with a J-inch

the ends slightly apart, bring them up from the lower side of the eye-
piece at an angle of 45 degrees, so that a thin cover- glass laid upon
them will reflect the image of the field, apparently upon the jjaper. I
have tried this expedient, which only took about three minutes to
carry out, and it was quite as efficient as the ordinary Beale reflector.

310 W. M. BALE ON THE

objective, in combination with an eye-piece giving a power of
about 370 diameters, there was a difference of about 22 diameters
between the results obtained when the collar was set at the two
extremities of its range. It should be set at a position suitable
for average slides, and always brought to that position when
measurements are to be taken. The fine adjustment should be
at about the centre of its range, if it is one of those which act on
the nose-piece only. I suppose it will rarely happen that the
field-diameter will vary in different directions, yet I have in one
instance found a slight variation, owing to the diaphragm not
being truly circular. In such a case the eye-piece may be marked
so as to show which diameter is taken. If a pair of eye-pieces
is in use they should be tested to see if the fields are equal ; if
not, one only should be used for measurements.

Having done the sums it remains to prove them, which we can
easily do by proportion. As the power of, say, a 1-inch with a
certain eye-piece is to the power of a one-fourth with the same
eye-piece, so will be the power of the 1-inch to that of the one-
fourth with any other eye-piece. If on making a series of com-
parisons like this the results correspond fairly with the figures
obtained by measurement, we may be satisfied ; if not, we must
conclude that there is an error somewhere. In a few instances
it may probably be found that the field measures an exact number
of micrometer-divisions without fractions ; the results in such
cases should reach a high degree of accuracy, and should be relied
upon rather than those in which there have been fractions to
estimate. For example, a 2-inch objective with a J-inch eye-
piece gave a field which measured 26 thousandths with the inch
micrometer, and 66 hundredths with the millimetre micrometer.

The effective magnified field-diameter was 6fV inches, or 157 milli-
metres ; the respective results therefore were 237 '98 and 237 '87
diameters.

Of course if we are certain that we have ascertained correctly
the powers of our whole series of objectives with any one ocular,
it will suffice to measure the powers of each of the other oculars
with one objective only, and then the powers with the other
objectives can be found by proportion.

We will now revert to the subject of the deduction to be made
from the apparent field-diameter to compensate for the unequal
magnification of the different zones of the field. When we speak

MEASUREMENT OF MAGNIFYING TOWERS.

311

of making a drawing at 10 inches distance we are apt to forget
that it is only that part of the drawing immediately below the

Fig. 1.

camera {i.e. the centre of the field) which is at that distance,
other parts of the drawing being more distant in proportion as

312 W. .M. BALE OX THE

they appioacli the edge of the field, and consequently being more
magnified. This will be best exemplified by making a diagram
similar to that given here (Fig. 1) but of the full size (which is
twice the diameter of the print). Assuming that the microscope
is placed in the usual position for drawing, A is the centre of the
eye-piece, and B C the surface for drawing on, the centre of which
must be 10 inches from A. The distance from B to C, 7 J inches,
represents the apparent diameter of the field, as projected on the
paper, this being the field of a Swift B ocular which gives the
largest field of any of my eye-pieces. Similarly D E, 41 inches,
represents the apparent field of a Swift A. We see at once that
rays apparently proceeding from about the margin have a con-
siderably longer path than those from the centre, and the exact
difference can be readily measured if we describe the arc F G.
having a radius of 10 inches from A. We see that while objects
at the centre of the field are drawn at a distance of 10 inches
those at B or G are drawn at about 10^ J ; their magnification
therefore exceeds that of objects at the centre in the same ratio
as that in which 10 exceeds lOyJ ; so that, supposing the central
part is magnified 100 diameters, the marginal part will be magni-
fied nearly 107, and the field-margin will appear farther from the
centre than it should. Let the arc F G he divided into 12 or
15 equal parts, and let lines be drawn from A through each of
the divisions to the line B C, and we shall see that the divisions
on B C are not all equal, those near the margins being slightly
longer, as the micrometer-divisions would be on a drawing. Now,
while the line B C is the apparent field-diameter as shown in a
camera-drawing, the real field-diameter, as taken at a uniform
distance from A of 10 inches, is the length of the curved line
F G. To measure this accurately the simplest way is to cut the
paper along F G and apply a flexible rule to the margin, when it
will be found that the field, which measures 1\ inches in the
camera-drawing, is really about 7fg-. Of course with an ocular of
small field the difference will be much less, as is conspicuously
shown in the diagram.

Instead of making a diagram we may proceed as follows :
take a strip of cardboard and bend it to the curve of the arc F G,
place it under the camera and prop the ends, holding it in such
a position that every part will be 10 inches from the centre of
the eye-piece, then mark on it the positions of the opposite edge*

MEASUREMENT OF MAGNIFYING POWERS.

313

of the field, as projected by the camera, when the field-diameter
so shown will be 7fV inches, corresponding to the line F G.

The observer who proposes to calculate his magnifying powers
by the foregoing method must of course substitute for the distances
B C and D E distances representing the apparent fields of his own
eye-pieces, and must be careful to secm'e accuracy, as the correct-
ness of all future measurements will depend upon it. It is well to
record the field-diameters in inches as well as in millimetres, to
be handy for reference when using either micrometer. But for all
ordinary purposes it will suffice to use the following table, which,
it is believed, is correct to the nearest millimetre. The first two
columns show the field-diameters as seen in a camera-drawing,
the third the amount to deduct. The remainder is the proper
field-diameter to be used in calculating magnifying power :

4 inches

= 101 millimetres,

deduct 1 mm

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While I have not seen this matter referred to in any book
specially in connection with the measurement of magnifying
power, I note that Mr. A. C. Cole, in his Methods of Micro-
scopical Research, refers to the distortion in drawing with the
camera, and somewhat drastically proposes that no eye-piece
higher than an A should be used for drawing with. This rule
seems to limit one's use of the instrument unnecessarily. The
distortion is mainly due, not to the greater power of the eye-piece,
but to the greater actual size of its field ; therefore the ratio of
distortion will be no greater with a jB or 0 eye-piece than with an
A , provided that we only utilise so much of the field of the former
as will correspond with the field of the A ; or better still (since
there is some distortion even with the ^4), if we confine our drawing
with all eye-pieces to, say, not more than 4 inches in the centre
of the field, shifting the paper from time to time so as to keep
within that area. Obviously the only way to get a camera-draw-
ing with equal magnification throughout a large field would be to

314 AV. M. BALE OX THE MEASUREMENT OF MAGNIFYING POWERS.

make the drawing on a concave plaque of such concavity that all
parts of its surface would be equidistant from the optic axis of
the eye-piece.

Of course camera-drawings are made at all sorts of distances
from the eye-piece, in order to obtain particular magnifications ;
and when they are made at other than the 10-inch distance, the
foregoing rule will obviously not apply. But in all cases when
using the camera the simplest way of indicating the magnification
is to mark off on the paper a few divisions of the micrometer
scale, placing the paper so that the part where the divisions are
to be marked is immediately under the camera.

315

THE MEASUREMENT OF MAGNIFYING POWER: A
NOTE ON MR. BALE'S PAPER.*

By Maurice A. Ainslie, R.N., B.A., F.R.A.S.

The method described by Mr. Bale of measuring the magnifying
power of a microscope is not by any means new ; it was described
by Mr. Nelson in a paper read before the Quekeftt Microscopical
Club [Journ. Q.M.C., Ser. 2, vol. xii. p. 239), and in the
English Mechanic for August 1st and 15th, 1913 (Nos. 2523
and 2525) will be found two letters of my own, giving several
methods of determining the diameter at 10 inches (or any
other specified distance) of the magnified field as seen through
the eye-piece. But Mr. Bale does well to call attention to this
method again, as it is without doubt one of the easiest as well as
one of the most satisfactory methods of arriving at the magnifying
power of the instrument as a whole, and also on account of its
having been hitherto so much, and so unaccountably, neglected
by writers on the microscope. The practical details of procedure
given by Mr. Bale are of great value ; but there are one or two
points to which I should like to draw attention, as being open to
objection.

In the first place, Mr. Bale is not quite correct in stating that
'' by substituting a higher eye-piece the powers of all the com-
binations must be increased in the same ratio." This may be
the case, but it is not necessarily so. For in the first place
the substitution of one eye- piece for another very often alters
the tube-length ; since this latter is properly measured from the
upper focal plane of the objective to the image plane, which for
normal eyes coincides with the lower focal plane of the eye-piece.
At any rate, the magnification produced by the objective alone

* The Hon, Editor is very much indebted to Mr. Ainslie for kindly
reading the MS. of Mr. Bale's paper and for adding the above note.

316 MAURICE A. AINSLIE OX THE MEASUREMENT OF

is proportional to this " optical tube-length," and since different
eye-pieces, when in position in the tube, very often have their
lower focal planes at widely different distances from the top
thereof, it follows that the magnification due to the objective is
often altered by change of eye-piece. This is, in fact, always the
case if any refocusing is required on change of eye-piece ; and
for this reason, as well as for the purpose of retaining the tube-
length (on the correctness of which the proper performance of the
objective so much depends) it is always desirable, on changing
the eye-piece, to restore the focus, if necessary, by alteration of
the tube-length.

But quite apart from this, there is another reason why the
powers given by different combinations do not always follow the
strict rule of proportionality as stated by Mr. Bale ; the magnify-
ing power of the objective, as stated above, is strictly proportional
to the " optical " tube-length, as mentioned above, and not to
the " mechanical " tube-length, which is the actual length of the
tube, measured from top to bottom. The optical tube-length of
course varies with the position of the upper focal plane of the
objective ; in one objective this may be as much as 50 mm. below
the bottom of the tube, while in another it may be as much as
50 mm. above it ; so that, even with the actual length of the tube
unaltered, tliere may be a variation, with different objectives, of
as much as 100 mm. in the optical tube-length, quite apart from
the variation introduced by change of eye-piece. It is obvious
that if the optical tube-length is thus altered by change of ob-
jective, the power of the objective ceases to be inversely pro-
portional to its equivalent focal length ; or, to put it in more
popular language, a "quarter" will not necessarily magnify
four times as much as an " inch."

It thus follows that it is not such a simple matter as it might
seem to compute the magnification of one combination from that
of another ; indeed, it is impossible to do so with any real approach
to accuracy unless the positions of the upper focal plane of the
objective, and of the lower focal plane of the eye-piece, are taken
into account.

An actual example may help to make this clearer. I have
measured the magnifying powers with two objectives — the Leitz
No. 1, focal length 39*4 mm., and tlie Zeiss 12-mm. Apo., focal
length 12'6 mm.: and two eye-pieces, the Holos "10," actual

MAGNIFYING POWER : A NOTE ON MR. BALE's PAPER 317

power 9*4, and the Zeiss Compensatiug " 8," actual power ITS.
The results are given in the following table :

Eye-piece ....

Holos '■

10"

Zeiss "8"

Zeiss "

Power of eye-piece

9-4

11-8

11-8

Tube-length (mechanical) in

mm. ....

107

167

185

Distance of lower focal plane

of eye-piece below top of

tube, in mm.

-3

+15

+ 15

Magnifying powers with :

Leitz No. 1 .

33-8

37 0

42-4

Zeiss 12-mm. .

142-0

160-5

178-0

The upper focal plane of the Leitz No. 1 objective is 28'5 mm.
above the lower end of the tube ; that of the Zeiss 12-mm. is
19"8 mm. heloiv the same. It follows that the optical tube-lengths
were as follows in the three cases :

Leitz No. 1 . . . . 141-5 123-5 UTo

Zeiss 12-mm 189*8 171*8 189-8

and the magnifying powers of the objectives by themselves
(optical tube-length divided by focal length of objective) were :

Leitz No. 1 . . . . 359 3-14 3*59

Zeiss 12-mm lo'OS 13-63 15'05

(The difference between the second and third columns is due to
the fact that for the second column the refocusinoj necessitated
by change of eye-piece was performed in the ordinary way by the
coarse adjustment ; for the third column, by pulling out the
draw-tube, so as to adjust the lower focal plane of the eye-piece
to the image, the position of the latter being unaltered ; in other
words, the " optical " tube-length is the same for columns one
and three, but not for columns one and two, as will indeed be
seen from the table.)

It will be obvious from the above table :

(1) That the magnifying power with the same eye-piece is not
inversely proportional to the focal length of the objective ; this
is due to the great difierence (in this case 19*8 + 28'5, or 48'3
mm.) between the positions of the upper focal planes of the
two objectives considered. In the present case the ratio of the

318 MAURICE A. AIXSLIE ON THE MEASUREMENT OF

focal lengths of the objectives is 39'4/12'6, or 3'125 ; but the
magnifications, in the case of the Holos " 10" eye-piece, are in
the ratio of 4'08 to 1, and in the case of the Zeiss eye-piece, 4'33
and 4*20 to 1, according as the focus was readjusted by the
coarse adjustment or the draw- tube.

(2) That the magnifying power is not proportional to the power
of the eye-piece, imless the optical tube-length is unaltered by
change of eye-piece ; the numbers given in columns one and three
for the magnifying power are proportional to the powers of the
eye-pieces, while those in columns one and two are not. The
substitution of the Zeiss eye- piece for the Holos, without alteration
of tube-length, increases the power 9*3 per cent, in the case of the
Leitz No. 1, and 13 per cent, in the case of the Zeiss 12-mm., the
ratios being r093 and 1*13 to 1 respectively. Neither of these
equals the ratio of the powers of the eye-pieces, which is 1*255 to 1.
Thus if the magnifying power were merely computed as pro-
portional to the powers of the eye-pieces, an error would be
introduced which would be greater in the case of the low- power
objective than in that of the high.

(3) The percentage difference between the magnifying powers
in columns two and three is greater in the case of the low-power
objective : 14*6 as against 10*8 in the case of the 12-mm.

It is therefore obvious that it is unsafe to attempt to compute
the magnifying power of one combination from that of another,
unless the positions (relative to the ends of the tube) of the
various focal planes are known ; in the absence of such know-
ledge, the power of every combination must be separately de-
termined. It is only fair, however, to say that the case here
taken is rather extreme, though by no means so extreme as it
might be ; if objectives (say a \ and an \) or eye-pieces of the
same type are compared, the errors in the result are as a rule
considerably smaller.

The error pointed out by Mr. Bale, due to the increase of
linear magnification at the edge of the field, undoubtedly exists ;
but I am not sure that it admits of quite such simple treatment
as he has indicated. Apart from the geometrical distortion which
he has dealt with, there exists in almost all eye-pieces a certain
amount of optical distortion of the image, towards the edge of
the field, and this optical distortion might very easily aflect the
results obtained ; sind it varies very considerably with the type

MAGNIFYING POWER : A NOTE ON MR. BALE's PAPER. 319

of eye^piece employed. Again, the term " magnifying power "
may either mean the ratio of the linear dimensions of the image
(supposed projected to some conventional distance, e.g. 10 inches
or 250 mm.) to those of the object ; or it may mean the ratio of
the angles under which the image and object are seen, both being
supposed at this conventional distance. If the latter meaning of
the term be adopted, it would seem that there is no real dis-
tortion of the kind mentioned by Mr. Bale ; and the only dis-
tortion would be that of an optical nature already alluded to ;
but if it is a case of linear ratio, then we must assume the image
projected on a plane surface, in which case the degree of flatness
of field of the microscope would enter into the matter. I do not
know that it really much matters, even at the edge of the field,
which way we look at the matter ; but it is worth while mention-
ing. As far as the centre of the field is concerned, there is of
course no difference.

Mr. Bale states that, broadly speaking, the method he describes
is the only one available in the absence of knowledge of the
separate powers of the constituents of the microscope. It is
therefore, I think, desirable to. call attention once again to a
method which has as yet received but scant treatment from the
textbook writers ; I refer to the Measurement of the Ramsden
Disc, or spot of light seen just above the eye-piece. I have given
full directions for this method in a letter to the English Mechanic,
August 15th, 1913 (one of the letters already alluded to), and
also some details in a lecture before the Photomicrographic
Society (see their Journal, February 1916, vol. v.. No. 1). I will
therefore only mention here that the formula employed is

M = 2D.A/d,

where M is the magnifying power of the instrument as a
whole, D the conventional distance of the image from the eye
(10 inches, or 250 mm.), A the N.A. of the objective (which
for this purpose must have its full value, i.e. must not be cut
down by the substage iris diaphragm), and d the diameter of
the Ramsden Disc. The latter can be measured by various
methods ; e.g. Banks' "Dynameter," Berthon's " Dynamometer,"
or a finely divided scale. As an example suppose D = 10 inches,
A=0-84, d=0-035 inch, thenM=20 X 0'84/0-035, or 480 diameters.
The great advantage of this method is that, given the N.A. of

320 THE MEASUREMENT OF MAGNIFYING POWERS.

the objective, only one measurement is required, and that it is
quite independent of the power of objective or eye-piece, or of
the tube-length ; it can be applied at any moment, without
altering any of the adjustments of the microscope, beyond opening
out the substage iris to its full extent, and without in any way
disturbing the object under examination ; and it is especially
easy to apply when dark-ground illumination is in use, as the
Ramsden Disc, though faintly illuminated, is then as a rule quite
easily seen, and if anything, more easily measured than a bright
disc. Its only drawbacks are that it really requires a special
instrument of some sort for measuring the R.D. — this, however,
is not difficult to improvise — and that when the R.D. is small the
accuracy of the method rather falls off, though it is still, unless
the R.D. is abnormally small, quite sufficient for all ordinary
purposes. For further details, especially in regard to the use of
this method when an immersion lens of N.A. greater than unity
is in use, I must refer the reader to my letters to the English
Mechanic already mentioned.

I may also mention that this method is analogous to the
ordinary method for finding the magnifying power of a telescope,
for which M equals A/d, where A and d are the diameters of the
object glass and Ramsden disc ; both of these formulae are easily
proved by means of what is known as the " sine-law."

Sown. Qvekctt Microscopical Club, Ser. 2, Vol. XIII., No. 81, November 1917.

321

SOME FURTHER NOTES ON COLLECTING AND
MOUNTING ROTIFERA.

By C. F. Rousselet, F.R.M.S.

{Read in Title October '2Zrd, 1917.)

Since 1893 I have published various memoirs on my methods of
preserving and mounting Rotatoria, which from time to time
have been modified and improved upon. It is my belief that I
liave now succeeded in arriving at a fair degree of perfection for
fluid mounts and seeming a realty lasting method of mounting
such slides, and it is my object in the following pages to
recapitulate the steps which have led to this result, some of
which liave not been recorded before. The members of the
Q.M.C. need scarcely be told how Rotifera are caught and
examined ; I will therefore only briefly mention the methods I
have used for years for collecting them in large numbers and
with the least possible difficulty. The starting-points for these
methods I learned at my first attendance at the Q.M.C. excursion
meeting in May 1883, in the north of London, probably Hamp-
stead Heath, led by Mr. John Hardy. I collected from the very
first with the Q.M.C. collecting-stick and net, as sold by C. Baker.
The collecting-stick in the shape of a walking-stick with a tele-
scopic joint, so that its length may be nearly doubled when
required, was invented by Mr. Highley about 1868, as mentioned
by Lionel S. Beale, F.R.S., in the 4th edition of his book, Hoiv
to Work ivitJi the Microscope (p. 147), and figured on pi. 35,
fig. 224. The net is an old Q.M.C. institution and was probably
introduced by Mr. Thomas Curties, of C. Baker's firm. It was at
first made with the thin muslin known as soft mull, but later on
I introduced silk (bolting silk No. 15 or 16) made in Switzerland

322 C. F. ROUSSELET ON

and now obtainable at a firm of mill furnishers in Mark Lane,
Bryan Corcoran & Co. This material lasts much longer and does
not clog or shrink so much as the former. The shape of the ring
net has always been the same as long as I am able to remember
it ; its size 6 x 5J inches wide, 6 inches long. The little bottle
I devised myself, making it 3J inches long by 1| inch wide, of
clear crown glass with a rimmed edge at one end. It was made
for me by a glass-blower of High Holborn named Mliller.*

When out collecting I used to fill one or two large square
bottles, and on arriving home I emptied their contents into a
couple of parallel-sided aquaria of various and suitable sizes.
These aquaria appear to have been first introduced by Thomas
Bolton, of Birmingham, and were exhibited by him at the
International Fisheries Exhibition held in the year 1881:, at South
Kensington. The size was originally 6 inches by 1 inch in depth
from back to front, which I considered rather too small, so I
had some constructed of a slightly larger size, 7 inches by IJ.
which answered admirably.

About 1889 I invented a tank microscope with an arm carrying
an aplanatic 6 mm. lens, so jointed that the lens could be moved
at pleasure parallel with the glass front of the tank and having
focusing adjustments by rack and pinion. At first this appara-
tus was fixed by screw-clamp to the tank itself, but afterwards
Mr. Charles Lees Curties suggested that it should have a separate
wooden base to enable me to replace one tank by another wlien
desired, without having to shift the clamp.

After a few hours' "rest" all the impurities and debris hud

* The same glass-blower made for me two kinds of glass pipettes:
(1) Fairly strong glass tube l-^% inch in width, 8 inches in length, with
the end drawn out gradually from the middle, for use with a red non-
perforated indiarubber teat (obtainable from Messrs, Baird & Tatlock,
of 14, Cross Street, Hatton Garden, E.C.); (2) Finer tube, 6-8 inches
long, with a funnel-shaped head, to be covered with thin indiarubber
membrane (such as is used to repair the inner tubes of cycle tyres),
by means of which single Rotifers, or a few, can be picked up by the
varying pressure of a single finger on the membrane and so trans-
ferred to wherever may be desired.

COLLECTING AND MOUNTING ROTIFER A. 323

settled down and the water had become sufficiently clear to be
examined with the hand lens. The aquarium having been placed
on a whatnot or dinner-waggon before a window or in front of
a lamp, candle or electric light, all the free-swimming Rotifera
collected on the side nearest the light and could then be picked
up by the score or hundred with very little dirt by means of a
pipette fitted with an indiarubber teat, and transferred to one
of my solid w^atch- glasses,* which being placed on the stage of
my Stephenson binocular enabled me to examine them under a
low power (3 inches).

Any form unknown or new to me could then be picked out
and transferred to the micro-glass trough or to my live-box or
screw compressor for further examination with the IJ incli or
higher power, and under dark-ground illumination.

After this preliminary selection the Rotifers in the solid watcli-
glass were first of all narcotised with 1 per cent, euca'ine and then
fixed and killed with one drop of J to J per cent, osmic acid, left
there for one minute only and then removed by means of a pipette
to several changes of 2 J per cent, formalin, in which they were
finally mounted. Formerly I recommended w^ashing in distilled
water, but the difference in density caused some species to swell
too much. This swelling can be controlled and regulated by
increasing or decreasing the percentage of formalin.

The 1 per cent, solution of osmic acid sold by opticians is as a
rule very much weaker than its nominal strength, as the acid
evaporates and gradually disappears ; moreover a 1 per cent,
solution will blacken and spoil the specimens if they are kept in
it even a very short time. For this reason and so as to know
the actual strength of the solution I was working witli, I found it

* In the earlj'^ days my friend ]\Ir. Dixon Xuttall had cut for nie
by one of his friends a number of squares of thick i^late glass, 1| to
2 inches square, and varying from f inch to J- inch in thickness. In
the centre of each square of glass I caused to be ground a cavity more
or less deep. These solid watch-glasses, as I called them, could not
only be placed singly upon the stage of my dissecting mici'oscope,
but when not so used could be placed one upon the other to protect
the contents from dust, etc.

JouRN. Q. M. C, Series II.— No. 81. 25

324 C. F. ROUSSELET OX

necessary to prepare it freshly every tliree or four months by
. dissolving the contents of a ^^ gram osmic acid capsule, breaking
the sealed glass tube in 10 grams of distilled water. This gives
a 1 per cent, solution which can be further diluted as required.

Having narcotised, fixed and killed the Rotifera, and having
passed them through the several changes of formalin solution,
the solid watch-glass was transferred to the stage of the
Stephenson binocular and the contents examined under a
2-inch objective. (In speaking of my Stephenson binocular
I ought to mention that it was a Swift model without any
condenser or sub-stage illuminating apparatus, but with the
body so mounted and arranged that it could be turned aside
when not wanted, thus leaving the stage quite free for manipu-
lation and the movement of the solid watch-glass and specimens.)
The different species could then be sorted out by means of a single
bristle (taken out of an old well-worn clothes-brush and mounted
in a suitable handle), and isolated in a micro-cell either singly or
collectively, the specimens being picked up and transferred by
the fine pipette.

The greatest difficulty I had was with Floscularia and Ste-
phanoceros. The latter I at last succeeded in preparing fully
extended in the following way :

I cut off small pieces of weed having one or more animals
attached, as a rule six specimens in all ; each of these I trimmed
as if ready for mounting. I then placed each of them separ-
ately in six different solid watch-glasses, with a pipette full of
perfectly clear filtered pond-water to which I added one drop
of 1 per cent, solution of Beta-Eucaine, never using or attempt-
ing to use more of the narcotic. At first the animals contracted
violently and assumed all manner of shapes. After a time, 10
to 15 minutes, they became quiet, and then I watched them
under the Stephenson binocular until 20 or 30 minutes had
elapsed, when I killed and fixed the first one by adding one drop
of J- per cent, osmic acid. If this failed I tried the next one five
minutes later and so on, until I succeeded in fixing the specimen

COLLECTING AND MOUNTING ROTIFERA. 325

nicely and fully extended. Being then sure that those remaining
were sufficiently narcotised, they were killed in the same way,
and each, when fixed, was immediately removed with a pipette
into 2J per cent, formalin and then transferred again through
several changes of the formalin solution so as to get rid of all
trace of osmic acid. Finally the specimen was transferred to a
cavity slide, covered and finished in my usual way.

In preparing non- free -swimmers I was greatly assisted by
Mr. Traviss's cutting and holding scissors,* by means of which a
small bit of pond weed to which the animal is fixed or attached
can be cut and transferred at pleasure.

In later times I have ringed my slides first of all with a very
thin ring of picture copal varnish followed by a coat of Japan
gold size, and then with several coats of Heath's cement (gold
size-shellac-indiarubber), finally finishing with three more coats
of gold size. Several persons beside Mr. Heath have produced
a micro-cement containing gold size and pure rubber, and
with the assistance of Mr. Waddington I have myself com-
pounded one containing pure caoutchouc dissolved in mineral
naphtha and mixed with gold size and Canada balsam. This
appears to answer very well, and to be a solution of a
problem which has puzzled microscopists for many years.
Messrs. Clarke & Page seem to have produced a cement wath
similar ingredients and properties, and Flatters & Garnett have
also done the same under the name " Brown Kinging Cement,"
the actual composition of which is kept secret, but, I take it, it
contains a small proportion of indiarubber, which appears to be
essential. I hope that Mr. Heath will get a reputable gold size and

* Traviss's cutting and holding scissors were first made by him
on the principle of a grape scissors which holds the grape that is being
cut off. More recently I advised Mr. Traviss to have his scissors
plated or made of nickel silver to prevent the blades rusting, and also
to have the handles made a little longer, say 4^ to 6 inches long, to
enable me to cut off a piece of weed with the animals attached thereto
under water in my window aquarium, to be then transferred to the
solid watch-glass, micro-trough, etc.

320 C. F. ROUSSELET OX

lac manufacturer to prepare his cement so that it may always
be obtainable at a reasonable price and in small quantities.*

The glass micro-cells require a further word. At first I had
great difficulty in obtaining suitable sunken glass slips. The
first specimens w^ere obtained from Birmingham, but the polish-
ing of the cavities was so rough and faulty that I gave them
up. After a time I discovered a firm in Hanover f where I
could obtain everything I required. Opticians here used to
charge me 2d. each for very inferior glass slides, but from tliis
firm I was able to obtain them finely polished at a wholesale
price costing less than IO5. a hundred.

Some years ago I also gave considerable attention to fresh-
water Polyzoa. My method of narcotising, fixing and mounting
has been fully described, with some additional methods of his
own, by Mr. H. E. Hurrell, F.R.M.S., of Great Yarmouth, in
the Micrologist, part 2, vol. iii., January 7th, 1916, published by
Mr. Abraham Flatters, 16-20, Church Road, Longsight, Man-
chester. I therefore need say nothing more on the subject.
Polyzoa require a larger cell for mounting than Rotifera, and
on this point I have some further remarks to make. After a
considerable search I found at Flatters & Garnett's some well-cut
glass cells (probably obtained from some makers in Germany),
cut and ground on both sides. These I treated in my own way
by painting on three successive coats of one of the caoutchouc-
gold-size cements, all within three days. I then dropped each of

* Last year Professor Topsent of Dijon informed me that M. Raclais,
Professeur a V6co\e cle Pharmacie cle Paris, had lately prepared a cement
to close preparations mounted in water. Owing to the war I have been
unable to ask for or to obtain this cement.

At an earlier date ]Mr. A. B. Aubert of New York City sent me a small
bottle of Micro-cement, which, however, I was unable to try at the time,
but as far as I can remember he mentioned that rubber was one of its
constituents. This year I wrote to him asking him for particulars
and details of its constitution. i\Iy letter, however, never reached him.

I The firm is called Deutsche Spiogelglas Actien-Gesellschaft, in
Freden a/d Leine, Provinz Hanover, CJermany, English glass manu-
facturers might take the hint to produce white glass micro-slides of
equal f|uality and finish.

COLLECTING AND MOUNTING ROTIFERA. 327

these cells on the centre of a cavity cell slide and placed the slide
on a metal table with spirit lamp underneath, which could be
H'emoved occasionally until I could see that the cement adhered
all round. Great care must be observed that the heat be not
too great or bubbles will appear in the cemented ring.

The slides thus prepared can be put aside till wanted. When
the time arrived I used to run a ring of Clarke & Page's cell
cement on the clean surface of the glass cell, and allowed
this to dry for twelve to twenty-four hours. Having pre-
viously selected a cover- glass which very slightly overlapped
the diameter of the cell, say by not more than y\- inch or J^
inch, I filled the cell with the mounting fluid (2i per cent,
formalin) and placed in it the prepared specimen, leaving
it there for a short time so as to enable me to prick any
air-bubbles with a needle or single hog's bristle. I then filled
the cell just full with as little as possible of this fluid and
placed one drop of fluid on the cover-glass, which was lowered
on to the cell and adjusted, using hardly any pressure, the
surplus fluid being taken up first with a pipette and then with
thin blotting paper or cigarette paper. After two or three hours'
time it will be necessary to examine the slide under the preparing
microscope to see that the cover is properly sealed all round
the edge, and, if need be, to add a drop of cement. If this is
found quite satisfactory the slide can be put aside for three or
more days, when further coats of Heath's or Clarke & Page's
or Flatters & Garnett's cement are to be added, leaving each
€oat three days to dry before adding the next.*

Bibliography.

1889. On a Simple Tank Microscope, Journ. QueJcett Micr. Club,

Ser. 2, vol. iv., pp. 53-54.
1892. On the Best Methods of Examining Rotifers under the

Microscope, Trans. Middlesex Nat. Hist. Soc, pp. 23-30.

* My slides of Rotifera and Polyzoa were presented to the Natural
History Section of the British Museum at South Kensington, where
they may be examined on apph cation to the curator.

328 C. F. ROUSSELET ON COLLECTIXG AND MOUNTING EOTIFERA.

1893. On a Method of Preserving Rotatoria, Journ. Quekett Micr.

Club, Ser. 2, vol. v., pp. 205-209.
1895. Second Note on a Method of Preserving Rotatoria, Journ.

Quekett Micr. Club, Ser. 2, vol. vi., pp. 5-13.

1898. On Some Micro-cements for Fluid Cells, Journ. Quekett

Micr. Club, Ser. 2, vol. vii., pp. 93-97.

1899. Note on Preserving Rotatoria, Proc. Uh Int. Congr. Zool.,

Cainbridge, pp. 197-198.

1901. Additional Note on Micro-cements for Fluid Cells, Journ.
Quekett Micr. Club, Ser. 2, vol. viii., p. 146.

1912. Notes on Improvements in the Method of Preserving Rota-
toria, Proc. lih Int. Congr. Zool., Boston, 1907, pp. 828-
830.

Journ. Qxekcft Microscopical Chth^ Ser. 2, Vol. XIII., Xo. 81. .\ovcmber 1917.

329

NOTE.
TECHNICAL OPTICS.

Arrangements have recently been completed for an important
development in national industry on the scientific side, by the
establishment of a new Department of Technical Optics in con-
nection with the Imperial College of Science and Technology at
South Kensington. The Department in question forms part of
a larger scheme adopted by the London County Council in August
last for the provision of instruction in this most important sub-
ject (in which the Council promised to find certain moneys for
the scheme, if the Government also contributed), including post-
graduate and research work at the Imperial College, a trade
school and senior day and technical courses at the Northampton
Institute, and junior technical courses at two junior technical
institutions, one in North London and one in South London.

Since August last the Government, including the new Depart-
ment of Scientific and Industrial Research and the Imperial
College, have decided financially to support the Council's scheme,
and all the necessary assents have been obtained. The amount
of money immediately available is £4,000 a year for working
expenses and £5,000 for equipment and more immediate neces-
sities of the Department.

The new Department is under the management of a Technical
Optics Committee of which the Eight Hon. Arthur H. D. Acland
is Chairman, and which at present consists of thirteen members
representing the Admiralty, the Army Council, the Ministry of

330 TECHNICAL OPTICS.

Munitions, tlie Royal Society, tlie National Physical Laboratory,
employers in the optical trades, glass manufacturers, and the
Imperial College ; while two further members have yet to be
elected representative of glass workers and metal workers. Tlie
same Committee appointed by the L.C.C. is also an Advisory
Committee to the Council.

Mr. Frederic J. Cheshire has been appointed head of the new
Department at the Imperial College for a period of five years,
witlk the title Director of Technical Optics, and Professor of
Technical Optics at the Imperial College. Mr. Cheshire's long
experience and great ability in optical matters practically ensure
a successful beginning. He has been associated with optical
instruments for many years at the Patent Office, and since the
formation of the Ministry of Munitions has been Deputy Director-
General of the Ministry and Technical Director of the Optical
Department of the Ministry. He is the present President of the
Optical Society.

It is expected that, subject to the conclusion of certain ar-
rangements with the Treasury, Mr. Cheshire will accept the
Directorship, and it is anticipated that the organisation of the
Department will be rapidly completed, and that training will
begin at an early date.

June 1917.

The recently established Department of Technical Optics of
the Imperial College at South Kensington has now begun its
work. It will be remembered that on the initiative of the London
County Council a general scheme for providing instruction in
tliis higlily important national work was agreed upon by the
several parties concerned in the early part of the year when an
Advisory Committee to the County Council representative of the

TECHNICAL OPTICS. 331

trade, the workers and other interests concerned was appointed
unde^he chairmanship of the Rt. Hon. A. H. Dyke Acland.

An important part of the scheme was the establishment of the
above Department, which is administered nnder the Governors
of the College by the same Committee. In June Prof. Frederic
J. Cheshire was appointed Director of the new Department ; in
July Prof. A. E. Conrady was appointed to the Chair of Optical
Design, and other subordinate appointments are in hand.

During the summer two courses of lectures were given on the
designing and computing of telescope systems, and attended by
sixty-six students, of whom forty-two came direct from the
workshop — a gratifying indication of the recognition by the
manufacturers of the importance of this work. About twelve
of these were men of academic distinction. The Ministry of
Munitions, the National Physical Laboratory, the Royal Obser-
vatory and Woolwich Arsenal were well represented.

This Session well-attended courses are being given in Optical
Designing and Computing, Practical Optical Computing, the
Construction, Theory and Use of Optical Measuring Instruments,
Theory of the Microscope and Microscope Technique. Every
effort is thus being made to meet the more immediately urgent
demands arising in connection with the war. A complete curri-
culum for Optical students will be introduced as soon as the
exigencies of the time permit.

The courses on the Theory of the Microscope and Microscope
Technique now in progress constitute the first effort of the
Technical Optics Department under the direction of Prof.
Cheshire to meet the needs of the users of optical instruments.
The microscope is perhaps the most important of all optical
instruments and the one for which there is the greatest com-
mercial demand, but unfortunately an exceedingly small propor-

332 TECHNICAL OPTICS.

tion of that demand has been satisfied hitherto by English manu-
facturers. It is hoped therefore in the courses referred to above
to excite a wider interest in the designing and production of the
microscope, and at the same time to insist upon the necessity for
greater technical knowledge and skill in its use.

The course on the Theory of the Microscope is being given by
Prof. Conrady and by the courteous permission of Dr. Burrows^
the Principal of King's College, the course of lectures on Micro-
scope Technique will be given by Mr. J. E. Barnard, Lecturer on
I^Iieroscopy at that College.

Journ. Quei:e(( Microscopical Club, Scr. 2, Vol. XIII- No. 81, yovembcr 1917.

333

NOTICES OF BOOKS.

On Growth and Form. By D'Arcy Wentworth Thompson.
xvi -I- 793 pages, with 408 illustrations in the text.
9 X 6 inches. (Cambridge: At the University Press, 1917.)
Price 2l5. net.

Prof. D'Arcy Thompson has laid us all under a debt of gratitude
in giving us this very fascinating book. Gathering a multitude
of illustrative facts from many and varied sources, and adding
many observations of his own, he has succeeded in showing us
what promise there lies in the endeavour to apply the laws of
physics and mathematical methods to the forms occurring in the
organic world. The style in which it is written is both dignified
and clear, and possesses a literary grace and charm which makes
reading a pleasure though dealing with such an abstruse subject
as the foundations of biophysics. " My sole purpose has been."
the author says, " to correlate with mathematical statement and
physical law certain of the simpler outward phenomena of organic
growth and structure or form : while all the .while regarding
ex hypothesis for the purposes of this correlation, the fabric of the
organism as a material and mechanical configuration."

It was Galileo who nearly 300 years ago enunciated what is
now known as the " principle of similitude," and the author
treats this as a preliminary to a fine discussion on the Rate of
Growth : dealing with growth in its relation to magnitude and
to that relativitv of maonitudes which constitutes form. " Rate
of growth is subject to definite laws, and the velocities in different
directions tend to maintain a ratio which is more or less constant
for each specific organism ; and to this regularity is due the fact
that the form of the organism is in general regular and constant."

To the microscopist, however, the chief interest will be found to
lie in the study of the conformation, within and without, of the
individual cell ; in the study of cell-aggregates and the forms of
tissues. In these chapters (IV-YIII) the author shows how

334 XOTICES OF BOOKS.

intimately the outward form and tlie intra-cellular phenomena are
related to physical laws such as those governing surface-tension
and those forces wliich are in opposition to it. The account of
mitosis is based on the provisional assumption that the pheno-
mena are analogous to, if not identical with those of a bipolar
electrical field. In the groupings of the daughter-cells in a
segmenting egg as well as in the arrangement of the cell-bound-
aries in the meristem of an apical bud or developing sporangium,
the author shows that the interpretation may be found in the
principles which govern space-partitioning in minimal areas, and
that we are but dealing with concrete instances of a subject, the
theory of which has fascinated mathematicians since the days
of Leibnitz and Euler. " Examples of these various arrangements
meet us at every turn, and not only in cell-aggregates, but in
various cases where non-rigid and semi-fluid partitions (or
partitions that were so to begin with) meet together. And it
is a necessary consequence of this physical phenomenon, and of
the limited and very small number of possible arrangements,
that we get similar appearances, capable of representation by
the same diagram, in the most diverse fields of biology." In
Chapter IX the spicular skeleton of sponges is dealt with, and
a particularly interesting discussion on the conformation of the
delicate and complex siliceous skeleton occurring amongst the
Radiolaria, which have such a wonderful and unusual appearance
of geometrical regularity. Prof. Dendy's presidential address to
this Club on the "Chessman" spicules in the genus Latruncula
and his paper in collaboration with Prof. Nicholson read at the
Royal Society in June, on the ringed spicules of an allied genus,
were published too late for reference by the author. The results
obtained in this research show that the rings of silica are deposited
at the nodes of a vibrating rod. Prof. D'Arcy Thompson would
have seen in these results another instance of the advantages
of mathematical methods. The general and mathematical pro-
perties of the logarithmic spiral are described, and the application
of these to the spirals of molluscan shells, in a very attractive
chapter, attractive not only for its matter but also for its beautiful
illustrations.

The micro-biologist will, however, pass onto the treatment of
the spiral shells of the Foraminifera. If the author's interpreta-
tion of the form and mode of growth of the foraminiferal shell be

NOTICES OF BOOKS. • 335

accepted — and this applies with equal force to the Radiolaria
referred to above — we shall be led to understand two striking
features of these groups of Protozoa ; on the one hand, the very
large number of diverse types or families and the large number
of species and varieties within each, and on the other hand, the
persistence of forms from very early periods to the present time.
" In the order of physical and mathematical complexity there
is no question of the sequence of historic time. The forces that
bring about the sphere, the cylinder or the ellipsoid are the
same yesterday and to-morrow. A snow-crystal is the same
to-day as when the first snows fell. The physical forces which
mould the forms of Orbulina, of Astrorhiza, of Lagena or of
Nodosaria to-day were still the same, and for ought we have
reason to believe the physical conditions under which they
worked were not appreciably different, in that yesterday which
we call the Cretaceous epoch ; or, for ought we know, throughout
all that duration of time which is marked, but not measured,
by the geological record."

The shapes of horns, of leaf-arrangement and phyllotaxis
and the shapes of eggs are dealt with, and the book closes with
a fine discussion, which is by no means the least interesting and
important, on the Theory of Transformations or the Comparison
of related forms. The comparison is made by means of Cartesian
co-ordinates within which are inscribed the outlines of related
organisms or their skulls.

In taking leave of this interesting and suggestive book, sug-
gestive alike to the biologist and mathematician, we offer our
congratulations to the author and to the syndics of the University
Press on its production.

330

PROCEEDINGS

OF THE

QUEKETT MICROSCOPICAL CLUB.

Ax the 523rd Ordinary Meeting of the Club, held on March 27tli,
1917, the President, Dr. A. B. Rendle, F.R.S., in the chair, the
minutes of the meeting held on February 27th were read and
confirmed.

Mr. Thomas E. Wallis was balloted for and duly elected a
member of the Club.

Before the regular business commenced, Past-President Pro-
fessor Arthur Dendy — now Vice-President — said he had great
pleasure in introducing to the members the new President,
Dr. A. B. Rendle. It was scarcely necessary to do so, as his name
would be quite well known to workers with the microscope, but
personally he might not be known to some of the members ; he
himself estimated it a great privilege to welcome Dr. Rendle to
the position. He was sure that if Dr. Rendle derived as much
pleasure and profit as he had done from the meetings, he would
be glad that he had accepted the post. He thought the Club
was greatly to be congratulated on Dr. Rendle's consent to
occupy it. In reply, Dr. Rendle thanked those present very
heartily for the kind reception they had given him and for the
honour they had done him by asking him to be President. Some
might think his position as Keeper of Botany did not imply a
great amount of association with the microscope. He miglit say
that the first paper he had read was on a microscopical matter.
It was on the structure of the seeds of the Lupin, and dealt
especially witli the development of the aleurone grains. His
second paper was also on a subject which required the use of the
microscope constantly for its determination. Although he might
to some extent have departed from his first love, he did still use
the instrument constantly, and that was a bond of union between

TROCEEDINGS OF THE QUEKETT MICROSCOPICAL CLUB. 337

himself and the members, which he hoped would be cemented
even more strongly, and he was sure that the time he spent with
them would be a source of profit and pleasure to himself, and
he hoped to them also.

The business of an Ordinary Meeting was then proceeded with.
One new member was elected, and proposal forms for three others
for consideration at the next meeting were read. Mr. W. Traviss
exhibited a little apparatus he had designed, by means of which
surface tension could be very effectively demonstrated under
the microscope. It was a small cone, open at the top, which
could be placed on the stage, and on a film of amyl acetate being
stretched across the opening evaporation at once commenced,
and under the microscope the currents set up in the film, and
its gradual thinning away, could be watched till breakage
occurred. Mr. A. E. Hilton showed under a microscope a speci-
men of Trichia afjinis, one of the Mycetozoa. It was reputed
common, he said, but he had not come across it yet in this
country. The present specimen h9,d come from Dublin. This
species has a hygroscopic capillitium, consisting of elaters covered
with spiral bands, which make them twist and move with any
alteration in the moisture of the atmosphere. His chief interest
in the study of the Mycetozoa was concerned with their bearing
on problems of biology, and in that connection he was very glad
that Dr. Rendle is the custodian of them at the British Museum.
The President, in commenting on Mr. Hilton's remarks, said he
was rather proud of having the group under his charge; they
were neglected by the zoologists, and the botanists took them up.

Mr. C. D. Soar then gave a description of two new species of
water mites, illustrated with lantern views of the entire speci-
mens and of the minute details upon which the discrimination
depends. One of the species had been found on Dartmoor, by
Mr. G. T. Harris, to whom the Club was indebted for many inter-
esting communications respecting his finds in that locality. Mr.
Soar had named it Dartia harrisii, in honour of the place and of
its discoverer. The other species belonged to the genus Eylais.
Mr. Soar had given it the specific name of Wilsoni in honour of
Mr. Wilson, who found four specimens at Staijies at one of the
Club's excursions. Besides describing the new species Mr. Soar
at the same time gave a short history of the genus and showed
how for many years only one species had been recorded, namely,

338 PROCEEDINGS OF THE

the type species Eijlais extendens Mull., but with modern methods
of preparation and mounting so many differences were recognised
in various examples that the genus was now broken up into an
immense number. The chairman said Mr. Soar was to be con-
gratulated on having added two new species to our fauna, and
joined with others in discussion on the subject of the address.

A paper by Mr. G. T. Harris, of Sidmouth, on " The Desmid
Flora of Dartmoor" was then read (in part) by the Hon. Secre-
tary. It began with a reference to previous records on the sub-
ject, and commented on their small number and the fewness of
the species which were attributed to the locality. Mr. Harris
then proceeded : " The section of Dartmoor dealt with in the
present paper is the great central portion comprised between
Cawsand Beacon on the northern extremity of the moor and
Believer Tor on the southern, with Metherall as its eastern
boundary and Lydford as its western. This area is roughly a
square of some one hundred and forty-four square miles, of un-
claimed more or less trackless moorland." In collecting over
this area it was divided into five districts for convenience. It
would have been impossible to enumerate tlie species of each
pool separately, so the plan of grouping the bogs and pools into
their respective districts was adopted. Collections were made
during July, August, September and October in 1915 and 1916.
The extent to which desmids are devoured by various aquatic
animals was noticed, and some remarkable instances recorded.
In one individual of a species of Euclanis no less than
twelve desmids were seen, and in another case a rotifer
had ingested seven. In the field each collection was kept
separate and duly labelled. Unimportant stations might yield
from seventy to eighty records, average-sized bogs 120 to 130.
while from more extensive and ancient bogs 230 species would
be recorded. Tables with the records of the various districts
were carefully kept, and, with plates illustrating a nuniber of the
more remarkable forms, will appear in the next number of the
Journal of the Club. Tlie nomenclature followed in tlie paper
is that adopted by W. and G. S. West in their monograph of the
British Desmidiaceae, as far as it is published. In closing, Mr.
Harris tendered his thanks to those who had assisted him in the
task of identification of his finds, most of whom arc members of
the Quckett Microscopical Club. There was some discussion

QUEKETT MICROSCOPICAL CLUB. 339

at the close of the paper, and many of those present bore testi-
mony to the interesting and valuable character of the communi-
cation. Mr. Bryce said that he had spent some time with
Mr. Harris, and was much struck with the richness of the neigh-
bourhood in all kinds of life. He had found his time quite taken
up with the Rotifera (his own special field), of which there was
abundance. Mr. J. AVilson, one of those mentioned by Mr.
Harris, said those who had not experienced it could hardly
realise the tremendous amount of work entailed by such a paper.
He had great pleasure in proposing a hearty vote of thanks
to the writer. This was seconded and dulv carried.

At the 524: th Ordinary Meeting of the Club, held on April 24th,
1917, the President, Dr. A. B. Rendle, F.R.S., in the chair, the
minutes of the meeting held on March 27th were read and con-
firmed.

Messrs. Charles H. Smith, Charles F. Sonntag, and William
R. Chappie were balloted for, and duly elected members of the
Club.

Dr. J. Rudd Leeson, F.R.M.S., then gave a lectm'e '' On the
House Fly, Musca domestica, with Special Reference to its Danger
to Health." This was illustrated by sixty lantern slides, and a
selection of preparations which were exhibited under micro-
scopes on the table. In his address which accompanied the
lantern views Dr. Leeson said : "It was not till 1882 that flies
were known to be the bearers of disease — then malaria was
traced to the mosquito. Nothing was known about the house
fly in relation to disease till 1905. Of all creatures it is the one
most commonly associated with man — everjrvvhere, from the
Polar regions to the Tropics. It is now known to be the carrier
of the microbes of anthrax, infantile diarrhoea, cholera (10,000
colonies were obtained from one fly), typhoid (the microbes have
been found in its intestines twenty- three days after ingestion),
ophthalmia, tuberculosis, diphtheria, pneumonia, etc. A
house fly was allowed to walk over a plate of sterilised gelatine
and a few hours later 46,000,000 germs of typhoid, diphtheria,
tubercle and pneumonia were counted."

Of 414 flies examined, the average number of pathogenic
organisms upon each was a million. The fly has therefore been

JouRN. Q. M. C. Series II.— No. 81. 26

340 PROCEEDINGS OF THE

unmasked by science as one of man's greatest enemies. It lias
110 true teeth, but obtains its food by suction. This passes into
the crop and subsequently overflows into the true stomach.
When the fly alights on any solid substance, such as sugar or
I'old meat, it vomits the contents of its crop upon it to soften
the material, which it contaminates to our cost. House flies
will vomit fifteen times an hour and defecate ten times ; these
habits constitute their supreme danger to mankind. The aver-
age of many fly censuses taken in England and America gives
the different species of house flies the following percentage :
Common house fly, 82 per cent. ; lesser house fly, 14 per
cent. ; stable fly, 1 per cent. ; blow fly, 1 per cent. ; other
species, 2 per cent. The wings move with great velocity :
in flying they make 330 complete strokes in a second. Nearly
the entire thorax is filled with the muscles connected with the
Avings, but the tracheal or respiratory system occupies more
space than any other; this makes the creature very buoyant.
Under the back of the wings are two drumstick-shaped append-
ages known as halteres, which are very characteristic of the
Diptera. Their purpose is not certainly known, but they
are supplied with, next to the optic nerve, the largest nerve
in the body. The mechanism of the proboscis was explained;
the long salivary glands and the intestinal system described.
The eyes, with their 4,000 lenses, and the three ocelli on
the top of the head referred to. Each of the ovaries contains
about 75 eggs in various stages of development ; 150 are laid
from four to six times in the life of the fly, but the blow fly lays
1,000 each time. The immense number of flies that one pair
would produce in a season, if all the progeny survived, was men-
tioned, one authority putting it at 500,000,000. The time taken
by the fly in passing through its life circle was spoken of ; it
depends greatly upon the temperature and general conditions,
but in the summer may be accomplished in about ten days. Its
ordinary life lasts about seven weeks. " Fortunately, flies have
their enemies : thread worms discomfort them from within, and
the fungus Empusa muscae attacks them from without with
deadly ellect. Mites worry them, beetles devour their larvae,
and wasps, robber flies, spiders, centipedes, ants, lizards and
birds all take their toll. One of the most unfortunate parts of
their anatomy is the innumerable hairs with which their bodies

QUEKETT MICPvOSCOPICAL CLUB. 341

•di'c covered, each bearing its thousands of micro-organisms."
The desirability of killing as many as possible, especially in the
spring before they have had time to breed, was insisted upon,
and steps which should be taken to this end were described-
One efficacious method is : " Keep a soup-plate with a piece of
bread, upon which the flies can alight to drink, nearly covered
with sweetened milk and water, in which is mixed a teaspoonful
of formalin, all other liquids being removed. In the early morn-
ing the flies will take their fatal draught." Protect all food
with wire gauze or muslin, particular care being taken in cases
where there is sickness in the house. All the principal points of
structure referred to in the lecture were illustrated on the screen,
and figures of the various species of flies other than the common
house fly were shown and brief directions given for their recogni-
tion. Several of those present asked Dr. Leeson questions on
various details, and at the conclusion of considerable discussion
the President expressed the thanks of the meeting to him for his
extremely useful lecture, the vote of thanks being confirmed
by acclamation.

At the 525th Ordinary Meeting of the Club, held on May 22nd,
1917, the President, Dr. A. B. Kendle, F.R.S., in the chair, the
minutes of the meeting held on April 24th were read and con-
firmed.

Messrs. F. Browning, Chas. Ed. Hearson, W. T. P. Cunning-
ham and F. Melhuish were balloted for, and duly elected mem-
bers of the Club.

Six names were read out as candidates for election at the
next meeting. Before the commencement of the usual business
the chairman said the members would be sorry to hear of the
death of Mr. Alpheus Smith. As most of them would remember,
he had been hon. librarian of the Club, and had held the office
for forty years. He was eighty-seven years of age. The an-
nouncement was received by those present standing as a mark
of respect, and the Hon. Secretary was directed to write a letter
of sympathy and condolence to the family of Mr. Smith.

Dr. J. Rudd Leeson gave a short description of a series of four
micro-preparations from the house fly. These were exhibited
imder microscopes on the table, and consisted of the ovipositor,

342 PROCEEDINGS OF THE

the eye, the head showing the brain and a mount showing what
Dr. Leeson considered to be a sense organ. This was found on
the coxa ; it was an oval organ, with six or seven white spots,
upon it, each bearing two hairs. He had not been able to find
a notice of it in any book, although it was a very singular and
definite structure. A hearty vote of thanks was accorded to
Dr. Leeson.

The President then gave an address on '' Colour in Plants and
its Preservation." The following is a condensed report of the
paper. It was stated that the object of the communication was
to show some of the results of attempts to preserve the colour
of plants in specimens destined for exhibition and to indicate
some methods with their possibilities and limitations. But it
would be helpful, first, to consider the substances with which
it would be necessary to deal. The colour of an object depends
on the quality of the rays of light which it reflects to the eye.
If no light is reflected it will appear black ; if all the rays which
make up white light are reflected it appears white ; and if only
a portion of the rays are reflected — others being absorbed — it
will have the colour corresponding to the rays which are re-
flected. Colour in plants is due to the presence of solid bodies
or solutions, which exercise a selective power on the rays of
white light which fall upon them. The solid bodies are special-
ised portions of the protoplasm ; at first white. On exposure
to light they develop a green pigment, chlorophyll, and are
known as chloroplasts. Later, by the formation of new pig-
ments, they may become yellow, orange or red, when they are
known as chromoplasts. The most important and widespread,
however, is the chloroplast, wliicli gives the green colour to the
leaves and young parts of the higher plants, and to the plant
body, or thallus, of the lower plants, algae and liverworts. In
the brown and red seaweeds it is masked by the presence of
other colouring matters. The green colour may be extracted
by alcohol. If the crude extract be shaken up with benzene,
a blue-gi'een dye is dissolved out, leaving behind a yellow
dye. Chlorophyll is an exceedingly complicated substance, in
the composition of which lecithins and possibly proteid com-
pounds take part. Most yellow, orange-yellow and orange-red
flowers owe their colour to chromoplasts. The pigment may be
uniformly distributed, but generally occurs as small amorphous

QUEKETT MICROSCOPICAL CLUB. 343

gi'anules or crystals. The crystals are carotin, so called because
first isolated from the root of the carrot. It occurs in some
flowers and in fruits, as the tomato. The most widespread pig-
ment in chromoplasts is yellow or yellow-orange. It is known as
xanthin. Nearly all yellow flowers owe their colour to it.

The soluble pigments exist in solution in the cell-sap. The
most important and interesting is the series of anthocyanins, to
which are due most of the reds and blues, and combinations of
these in purples, violets, etc. They are almost universally dis-
tributed, and occur normally, or as the result of unusual condi-
tions. Anthocyanin iff often associated with damp- and shade-
loving plants, and is developed specially on the under surface of
leaves. The leaves of water-lilies and other aquatics are often
light green above and deep violet below. The variegated plants
of cultivation — Caladium, Dracaena, Coleus, Begonia, etc. —
were also referred to. The autumnal coloration of leaves is
due to anthocyanin. Low temperatures may induce its forma-
tion, and it occurs in Arctic plants and in many evergreen shrubs
and herbs during winter. The colour of copper beech and
similar varieties is due to its presence. Chemically, the antho-
cyanins are a class of substances, somewhat allied to sugars,
known as glucosides. They are soluble in water and generally
in alcohol, and may be obtained in the crystalline form. They
give a bright red colour when treated with acids, and generally
green with alkalies. A great deal of interesting work has been
done and much has been written on the relation of these sub-
stances to the process of photosynthesis, to the effect of tem-
perature, light, drought, presence of oxygen, excess of sugar in the
tissues and to other conditions and factors. Their physiological
significance has been much debated, two rival views having been
advocated : first, the " light screen " hypothesis ; secondly, the
"" heating" hypothesis of Stahl. A fair number of flowers owe
their colour to another series of soluble pigments, the xantheic
series, which are yellow, orange-yellow or red. They occur in
primrose, yellow rose, narcissus, eschscholtzia and others. The
colour of a flower is frequently a combination of effects, usually
of an anthocyanin in the epidermis overlying cells containing
chromoplasts ; where blue anthocyanin overlies yellow chromo-
plasts, green is formed, as at the base of the yellow petals in some
tulips.

344 PROCEEDINGS OF THE

The process of treating the green parts of plants, notably
flowering plants, with a solution of copper acetate dissolved in
strong acetic acid was proposed by Prof. Trail, and his direc-
tions for using a hot solution are now recognised as generally
the best method. The object of the process is to form per-
manent green compounds of chlorophyll and copper. The
fresher the plant the more successful will be the treatment. In
spring, when the leaves are young and active, the result is better
than in autumn. Deciduous-leaved plants, as a rule, green
quickly and well, while evergreens require protracted boiling,
some changing to brown at first, but after twenty to forty
minutes' boiling this gradually gives way to green. Glass or
porcelain vessels should be used for treating specimens with the
boiling solution. Drying after the process may be by pressure
in drying paper or in hot sand, the choice depending on the
texture of the plant.

Dr. Rendle exhibited a large number of specimens of various
plants preserved by the method he had described. Some ferns
were particularly beautiful, the vivid green colour giving them
an extremely natural appearance. Liverworts, mosses and
selaginellas all retained a most life-like aspect. Specimens of red
seaweeds which had been permanently stained to represent the
natural colour were also shown ; and several specimens of flower*
which had been dried in hot sand or the Fothergill press, notably
a delphinium and a scarlet geranium, in which the brilliant colours
seemed altogether unchanged by the process of drying, in some
cases after an interval of many years ago.

Mr. N. E. Brown then showed a number of dried herbarium
specimens, in most of which the colour was excellently kept,
although they had been prepared many years ago. He said
that it was evident that the means which proved successful in
one case might not answer in another, but he had found tliat
the best method was to carry through the drying process as
quickly as possible, and that it should be done at a somewhat
high temperature.

Mr. F. J. Perks said he was sure the members would wish to
accord a hearty vote of thanks to the President for his interesting
and valuable address and for the trouble he had taken in bring-
ing the very beautiful specimens to the meeting. The proposal
was agreed to by acclamation.

QUEKETT MICROSCOPICAL CLUB. 345

At the 526 th Ordinary Meeting of the Club, held on June 26th,
the President, Dr. A. B, Rendle, F.R.S., in the chair, the minutes
of the meeting held on May 22nd were read and confirmed.

Messrs. Rob. H. Thomas, W. T. Waller, Henry Williams,
Stanley Lindwall, Joseph Edgar and J. Goodhart Evans were
balloted for, and duly elected members of the Club.

The appointment of Mr. Frederic J. Cheshire — a member of
the Club — as head of the new Department at the Imperial Col-
lege, with the title Director of Technical Optics and Professor
of Technical Optics at the Imperial College, was referred to by
the chairman.

Mr. Burton called attention to an exhibit under a microscope
on the table, which appeared like a cellular membrane, the cells
more or less hexagonal in shape. He said at the Club's excur-
sion to Ealing the surface of one of the ponds was to a large
extent covered with a thick green scum, which also spread over
grasses and various objects floating on the water. This proved
to be Euglena viridis in an encysted state. When conditions
w^ere favourable the euglenae often rose to the surface, and there
became encysted, each individual assuming a spherical form and
surrounding itself with a firm cell-wall. When very numerous,
owing to pressure the cells become hexagonal, or distorted, and
adhering together, form a kind of skin or pellicle ; it was an
instance of this which caused the appearance noticed at Ealing.
After a time division into two (or sometimes four) takes place
in most of the individuals, which then emerge, leaving the empty
and colourless cells floating. As they have some amount of
cohesion they may continue as a thin pellicle for a time. It has
been mistaken for an alga, and was described as such. By care-
ful management portions may be brought away, and can then
be mounted as a permanent object.

Mr. N. E. Brown, A.L.S., then gave an address on '' Evolu-
tion as Illustrated by a Genus of Plants." He passed round a
small flower-pot, which contained four very singular-looking
plants ; they were cone-shaped, with the apex downwards, of
various sizes up to about 1| in. high, and each had a small orifice
resembling a closed mouth at the top. He said : " Each of the
specimens is a distinct species, and, although very small, each is
a full-gTown adult individual that has reached the flow^ering
stage, and although each will branch and ultimately form a small

346 PROCEEDIXGS OF THE

clump, the individuals of that clump will not be very much larger
or smaller than those before you." Attention was directed to the
small closed orifice at the top, resembling a tiny mouth with
closed lips. They were rare plants, three of them undescribed and
unnamed species at present. The audience were invited to give
the name of the genus, or even of the order to which they
belonged, if able, but no one seemed inclined to attempt this.
Mr. Brown was not surprised, and remarked that " when the first
species of this group was described and figured in 1738, its dis-
coverer, Johannes Burmann, Professor of Botany at Amsterdam,
mistook it for one of the puff-ball fungi." Mr. Brown said he
wished to show some of the stages that seemed clearly to indi-
cate the connection of the simple forms seen in the pot before
them with other forms that appear to have no resemblance what-
ever to these. " The divergence of the species of this genus
is very great and remarkable. To start with, we have humble
and simple plants like those shown, and radiating from them as
an initial stage are many lines of development — one line cul-
^linating in a shrub 15 ft. high, another ending in a herb with
a loose tuft of a few erect leaves as large as those of a lettuce,
and trailing flowering stems two or three feet long and an inch
thick. Yet the flowers throughout the genus vary very little
except in size and colour. The genus is Mesembryanthemum,
commonly called ice-plants. This particular group of the genus
is one of the most remarkable at present living, and has two
special points of interest : — (1) With the exception of the
members of the order Rafflesiaceae, in their vegetative organs
they are the most primitive and simple of all Dicotyledons, and
quite unlike any others in existence ; (2) the peculiar manner of
their growth, which seems utterly unlike that of any others, and
yet, when critically examined, is found to follow the same
general rule as other flowering plants. It is a recognised fact
that, however widely adult organisms may differ, yet in their
embryonic stage they are often similar. AVe note that when we
sow seeds belonging to a great variety of plants belonging to
different orders, when the seedlings first appear there is often
a great similarity in their form." This is the case in the seedling
stage of Mesembryanthemum, but in the group to which those
shown in the pot belong, the seedlings are reduced to the most
primitive condition possible. ''In most cases, as the pliuit

QUEKETT MICROSCOPICAL CLUB. 347

develops, it assumes quite a different form from that of tlie
seedling stage, but some members of this group only depart
from the embryonic form to a slight extent dm*ing the whole
of their life. Therefore we may fairly consider this group to
represent the primitive stages from which the more complicated
members of the genus have step by step developed." Instances
were given here, and sketches illustrating the various stages
were drawn upon the blackboard, making the matter very clear
and definite to those present. Mr. Brown remarked that, before
proceeding to trace a connection from species to species, it is
necessary to understand the structure of the plants. In this
connection he said : " If a transverse section of the body is
made, it is found to consist of an elliptically shaped slice of
soft, watery tissue, with a small, narrow, slit-like cavity at its
centre, corresponding to the orifice at the top." A flattened
tubular canal extends from the orifice almost to the base
of the plant, where, at the right season, either a young flower-
bud or a young vegetative bud will be found. If a flower,
it will ultimately grow up, push through the orifice, and expand.
At the base of the flower-stalk, inside the plant, one or two
vegetative buds form. At the very base of each plant the tissue
becomes firmer, sometimes more or less woody, finally assuming
the character of an extremely short, or more or less elongated
stem, according to the species. The solid-looking body of the
plant is really formed of two opposite fleshy leaves, united to
each other, with the exception of the canal which runs down the
centre. All the specimens in the pot passed round were con-
structed in this way, so that each is stemless, or nearly so, and
consists of a pair of simple fleshy leaves united into a single
obconic or globose body, thus representing a very primitive type
of plant so far as the vegetative organs are concerned, whilst the
flowers are of a highly complicated structure. The manner of
growth is remarkable. During the summer the vegetative buds
in the interior, at the bottom of the canal, gradually develop, and
as they enlarge the water and food material stored up in the fleshy
leaves is gradually absorbed, so that the visible part appears as
if the plant is dying, and at length becomes a mere dry, crumpled
skin, concealing the young growth, which ultimately bursts
through.

" In tracing the gradual evolution of the more complex forms

3i8 PROCEEDINGS OF THE

from the simple ones, the first change noted is that in some specie?^
tliere is a slight depression across the top, by which the apices
of the combined leaves on each side of the orifice slightly overtop
the latter. In another species the depression is more pronounced :
in another it becomes a distinct notch ; in another the notch is
deeper and tlie plant is two-lobed. These are all indications of
the progressive separation of the two leaves of which each plant
is composed. In different species the separation becomes more
and more apparent, until we find forms in which the two leaves
are separated nearly or quite, to their base. This progression
will only result in the plant having but two perfectly developed
leaves, besides the withered remains of the old ones, at the same
time. Other species, however, will show a tendency to develop
a new pair of leaves before the old pair have begun to shriveL
and from such forms the transition is easy to such as normally
have two pairs always present, and from these to others having
three or four pairs present on each growth, forming a tuft. The
passage of this type to that with several or many leaves in a
rosette is exhibited by many species. Such a progressive change,
although finally leading to several different types of modification,
is produced without any gieat development of the stem. But the
development of the shrubby forms from these can also be traced.
Several of the primitive species with age gradually develop short
stems and branches, which, becoming covered with earth, are
more or less subterranean. Some, however, gradually develop
short stems above the ground. From such types a passage to
another and distinctly shrubby form is arrived at by the internodes
developing in varying degree according to the species. Finally,
you may have a shrub 15 ft. high, formed by the superposition
of one segment on another, each having a short woody stem
(internode) at the base. I am not mentioning their specific
names, because most of tlie plants shown arc new species, and
liavc not yet been named. It is not possible to show all the
stages of connection, as that would require a gi'eater number
of specimens than could be brought together, but examination
will, without showing every link in the chain, make sufficiently
clear the manner in which the lines of development have pro-
gressed, by a slight modification here, and another there, until
a totally different type has become evolved."

Reference to a large numl^er of living plants and blossoms.

QUEKETT MICROSCOPICAL CLUB. 349

which were exhibited at the meeting, as well as some beautiful
drawings, and also sketches on the blackboard, proved and
emphasised the various points Mr. Brown gave in his lecture.
At its close several of the audience raised questions of interest
and joined in a discussion on the subject. The President, in
moving a vote of thanks for the lecture, said : " We have
heard the result of original, careful and laborious investigation,
and we feel highly complimented that Mr. Brown has brought
80 much of the fruit of his work on these plants before us,
and explained it so lucidly."

350

OBITUARY NOTICES.

ROBERT BRAITHWAITE, M.D., M.R.C.S., F.L.S.,

F.R.M.S.

May Wth, 1824:— October 20th, 1917.

It is with niiich regret we have to announce the death of Dr.
Braithwaite in his ninety-fourth year ; he was the eldest son of
Robert Braithwaite, shipowner of Ruswarp, near Whitby, where
he was born in 1824. He was educated at the Grammar School
at Whitby and afterwards studied medicine, becoming M.R.C.S.
in 1858 and M.D. of St. Andrews in 1865. He married the
daughter of Dr. N. B. AVard, F.R.S., the inventor of the Wardian
case and a botanist of repute, who was then practising at Clapham.
Dr. Braithwaite succeeded to the practice, which he carried on for
many years in Ward's old house, " The Ferns," 303 Clapham
Road. About twenty years ago the house, like many others on
the main roads near London, was demolished, and red-brick
fiats now occupy the site. His leisure time w^as devoted to the
study of the Moss Flora of his country and of Europe jzenerally.
and in this subject he became the greatest authority.

Fie was elected a member of the Q.M.C. in the year of its
foundation, and in the following )^ear (1866) became F.R.M.S.
He was President of the Club during the years 1872-71, and in
tliat period delivered six lectures on the Histology of Plants
which appear in the First Series of the Journal (Vol. III.) and are
illustrated with drawings from his skilful pencil. A very interest-
ing contribution to the Journal Q.M.C. was read in January
1870 on The Geographical Distribution of Mosses in Europe. This
paper forms an early ecological study of moss-groups.

Dr. Braithwaite joined the Linnean Society in February 1863.
and was one of the longest-standing members. He served on
the Council 1872-71 and 1889-92. juid was n Vice-President
1889-91.

JOURN. Q. M. C.

Ser. 2, Vol. XIII, PI. 22.

Ai.i'iiKiri Smith,

AdUird 4' Sou 4" HVxt Neiriiinu, Ud.

OBITUARY NOTICES. 351

Dr. Braitlnvaite's magnum opus is The British Moss Flora,
tlie publication of which was completed in 1905 in three large
octavo volumes and constitutes the standard work upon this
subject. The 128 plates were engraved from drawings made by
the author, and the whole work forms a remarkable monument of
his great skill and industry. In addition Dr. Braithwaite pub-
lished a monograph on the Peat Mosses : The Sphagnaceae or
Peat Mosses of Europe and North America.

Dr. Braithwaite' s very large collection of separata relating to
the Musci is now in the Library of the Royal Microscopical
.Society. They together form ten volumes, and are indexed in
the First Supplement (1910) to the Library Catalogue.

His herbarium of British Mosses, which is authoritative for his
work The British Moss Flora, was purchased a few years ago
by the Trustees of the British Museum, and is available for con-
sultation in the Department of Botany.

ALPHEUS SMITH.

1830—1917.

It is with much regret we have to record the death of Mr. Alpheus
Smith, which tookplace at his residence in Streathamon May 16th.
Mr. Smith joined the Club on May 25th, 1866, and for over forty
years served the Club in the office of Honorary Librarian. He
was born at Arundel in 1830, and was educated at Guildford, and
for forty-seven years was the trusted employe of a firm of leather
merchants. Mr. Smith was a member of the Library Association
of Great Britain and a well-known figure at their annual congresses.

As Librarian of the Club he was well known to many of our
members, who much appreciated his courteous maimer and un-
failing helpfulness. Although his interest in microscopy was
but slight, he found in the duties he had undertaken and performed
for so many years a source of much pleasure. He was elected
an honorary member of the Club in 1912, and his last appearance
at a meeting of the Club was on the occasion of the fiftieth
anniversary.

The portrait of Mr. Smith is from a recent photograph.

353

THE PRESIDENT'S ADDRESS.

THE USE OF MICROSCOPICAL CHARACTERS IN
THE SYSTEMATIC STUDY OF THE HIGHER PLANTS.

By a. B. Eendle, MA., D.Sc, F.R.S.

Keeper of Botany, British Museum {Natural History).
{Delivered February I2th, 1918.)

The study of microscopic organisms is one in which members of
the Quekett Club are so well versed that it is unnecessary to refer
to the value of the microscope in the systematic discrimination
of their families, genera and species ; many of the objects of your
study are recognisable only under a fairly high power. Even in
those groups of the lower plants where the individual attains a
considerable size the characters which are regarded as of value
for the determination of its systematic position enjoin the use of
the microscope. Seaweeds cannot be studied apart from the
microscope ; and the determination even of the larger Fungi
becomes merely a question of matching unless minute characters,
such as those associated with the spore, are studied.

You cannot get very far in the study of Lichens without the
microscopic examination of a section ; and the description of a
genus, or even of a species, is not now considered complete without
reference to the number, shape, size or special characters of tha
spores.

In the study of Mosses " the cells of which the lamina of the-^.
leaf consists furnish characters of the greatest importance both
on account of the ease with which they can be observed and their-
high degree of constancy ' ' — to quote the author of that excellent .
guide to the study of British mosses, Mr. H. G. Jameson.

The Ferns are eminently macroscopic plants, but an examina-
tion of the frond does not carry us far, and even for the recognition,
of the larger groups an examination of the structure of thej
sporangia is necessary.

JouRN. Q. M. C, Series II.— No. 82. 2?

354 A. B. RENDLE ON THE USE OF MICROSCOPICAL CHARACTERS

In tlie highest groups, those comprising the Flowering or Seed
Plants, the development of an inflorescence, flower, fruit and seed,
has supplied macroscopic characters on which our system
of classification has been based. But there is an increasing
tendency to use minute characters as supplementary to or in
conjunction with the macroscopic; and in the case of limited
miaterial the study of minute characters becomes of the greatest
value. In the study of fossil plants, w^here the material consists
often of specimens showing only stem- structure, the worker has
to depend entirely on his microscope for their systematic elucida-
tion. I need not remind you of the large amount of recent work
in this branch of botany in which the diagnosis of specimens
■depends entirely on internal structure as revealed by the micro-
scope, or of the great value of the results obtained as bearing on the
phylogeny of the higher plants. I do not propose to go into this
in detail. In modern flowering plants there is also considerable
-variety in the details of the stem- structure as revealed by the
•examination of a section under the microscope, and indications
-of the systematic position of the plant in question may be
obtained by this means; but there is room for a much more
•extensive and careful study on these lines.

The earlier group of the Flowering Plants, the Gymnosperms,
by far the greater number of which are included in the Coniferae
Opines, firs, etc.) are distinguished from the later group, the
Angiosperms, which includes the great majority of modern trees,
shrubs and herbs, by a remarkable uniformity in the structure of
the secondary wood. This is due mainly to the absence, as seen
in cross-section, of the larger openings which represent the vessels,
which are a characteristic feature of the secondary wood of
Angiosperms. Among the conifers the wood of the yew shows
the greatest uniformity, as it consists of one kind of tissue only,
tracheides, the regular arrangement of which is unbroken by the
thinner-walled cells (parenchyma) which accompany the tracheides
in other conifers, and by the resin-canals which frequently occur
Yunning longitudinally between the elements, as in pines, firs,
larch and others. Here, there are minute characters which
enable us to determine even small fragments of wood as coni-
ferous, and among these to discriminate yew. The systematic
■determination of plants by characters supplied by the wood is
a matter not merely of academic interest. Valuable information

IN THE SYSTEMATIC STUDY OF THE HIGHER PLANTS. 355

on the nature of the past flora of a region may be gained in this
way, from the examination of long-buried fragments of wood.
The antiquarian or ethnologist frequently wishes to know the
nature of the wood of which some article of interest to himself
is made. And the bore will invite you to diagnose the botanical
nature of his walking-stick. If time is precious the last-named
may generally be choked-off by suggesting the necessity of
cutting a cross-section.

A case which frequently recurs is the discrimination between
oak and chestnut in connection with the timber-work of old
buildings. The trees themselves are so distinct in habit, and in
character of leaf, flower and fruit, that it maybe a little surprising
that there should be a difficulty in distinguishing the two timbers.
The component parts of the wood are, however, similar in the two
species ; and though what we call a typical piece of oak is distin-
guished without difficulty from a typical piece of chestnut, there
are certain varieties of oak which so closely approach chestnut
as to give rise to considerable difference of opinion among experts
as to the nature of the wood.

You may remember a controversy a few years ago, when the
roof of Westminster Hall was undergoing repair, as to whether the
original structure was oak or chestnut. There was difference of
opinion among experts, but the view which was ultimately
accepted, I think rightly, was that the structure is oak. I have
recently been asked to give an opinion as to the nature of the
wood used for the roof of the hall at Winchester School. Tradi-
tion calls it chestnut, but microscopic examination leads to the
conclusion that it is oak. The nature of the thin layers of wood
used in the construction of the propellers of the Zeppelins which
were brought down near London supplied problems which were
of interest to us at the Museum, and were also, I believe, of some
importance to those in authority.

The microscopic study of timber-structure is of considerable
importance commercially. Timber is put on the market under
some name known in the trade, and the assumption is that the
sample will have the properties of tensility, rigidity, durability,
etc., which are associated with that name. These properties, or
their proper combination, may be of vital importance in connec-
tion with the use to which the timber is to be put. For instance
in the manufacture of an aeroplane an insufficiency in one respect

356 A. B. REXDLE ON THE USE OF MICROSCOPICAL CHARACTERS

may cause disaster. But in timber from allied species, there may
be a close general resemblance associated with important specific
differences which are recognisable only by a microscopic study
of the minute structure. We are beginning to appreciate the
importance of an intensive study and a careful photo micrographic
record of the minute structure of the timber of species of economic
value.

The forests of tropical Africa are rich in a great variety of hard
woods. Much of the so-called African mahogany which is put on
the market is the product of trees the genera and species of which
are not adequately known. The original Honduras mahogany is
the product of a Central American species, Swietenia mahogani,
the African woods belong to other genera of the same family,
Meliaceae, and there is need for a careful systematic study of their
species, as embodied in the characters of foliage and flower, in
association with the study of the minute structure of the wood.
The microscopist in association with the systematist can do work
of great importance.

I have referred to the simplicity of the secondary wood in the
Gymnosperms as contrasted with the variety of elements of which
it is composed in woody Dicotyledons. The most striking dis-
tinction between these groups is the absence in the former of that
definite aggregation of sepals, petals, stamens and carpels which
we call a flower and the remarkable development and variety of
which is such a characteristic feature of the Dicotyledons. A small
family of the Gymnosperms, the Gnetaceae,is exceptional in having
a wood-structure similar to that of the Dicotyledons, and also an
arrangement which is somewhat suggestive of the flower of certain
Dicotyledons with a very simple type of flower. The question
arises whether this resemblance is an indication of relationship,
and an attempt has been made to trace the ancestry of the Dicoty-
ledons back through this group. But the three genera which are
associated in the family Gnetaceae are plants highly specialised
for life under somewhat peculiar conditions — one is a tropical
woody climber, the others are adapted for growth in desert areas —
and one hesitates to draw far-reaching conclusions on relationship
from such specially adapted organisms. We bear in mind the
remarkable differences in habit and vegetative structure of species
even in the same genus where they are adapted to different
conditions of life.

IN THE SYSTEMATIC STUDY OF THE HIGHER PLANTS. 357

The wood of the Dicotyledons contains, besides the tracheides,
vessels, recognised in the transverse section by larger openings,
thick- walled fibres of various kinds and shorter regular- shaped
elements or parenchyma. The considerable variety of combina-
tions of these elements which is possible accounts for the variety
in appearance to the naked eye, but more especially under the
microscope, of the wood of dicotyledonous plants. Closely allied
species generally show a resemblance in the structure of their wood,
and certain characters are often common to genera or groups of
genera ; but on the other hand, genera which from every other
consideration are regarded as occupying widely removed positions
systematically, may be closely alike in the structure of the wood.
A striking example occurs in the wood of Drimys, a species of
which supplies the drug known as Winter's Bark,* which in its
remarkable uniformity of structure resembles the yew. This
resemblance has been used in support of the view that the Mag-
nolia family, to which Drimys belongs, comes very early in the
scale of development of the Dicotyledons and approaches most
nearly the Gymnosperm ancestor from which the Dicotyledons
may be presumed to have been derived.

But in view of the fact that the wood-structure in the Magnolia
family belongs otherwise to a type which is one of the commonest
among the Dicotyledons, one hesitates to use an isolated instance
to support so far-reaching a conclusion in phylogeny. At present
we can only say that we know too little as to the meaning of these
variations in the character of the minute structure of wood, and
as to how far they are expressions of relationship or the results
of comparatively recent adaptation to environment. But I think
I have said enough to show that the microscopist has here a wide
field of investigation and an opportunity for work not only of
purely scientific but of great economic value.

An anatomical character which is of value for systematic pur-
poses is the presence and character of the receptacles containing
secretions of various kinds. The secretion may be contained in
epidermal outgrowths of the nature of hairs, the structure of
which may be more less characteristic of certain families or
genera, as in Pnmula, Pelargonium (the Geranium of gardens),
and many members of the Dead-nettle family which owe their

* This bark was first brought to Europe in 1579, by Captain Winter,
who accompanied Sir Francis Drake to the Straits of Magellan.

358 A. B. REXDLE ON THE USE OF MICROSCOPICAL CHARACTERS

characteristic odour to the secretion which is developed in the
hair-cell between the cuticle and the outer wall, the secretion
being set free by rupture of the cuticle.

In the interior of the tissue the secretion may be formed within
special cells, which may be very long and often branched, as those
which contain the milky juice or latex in the spurges and other
members of the Euphorbia family, or may consist of short elements
placed end to end and perforated, forming vessels, as in the latex-
containing tissue of dandelion, chicory and other members of the
family Compositae ; or canals may be formed by the separation
of rows of cells, leaving a long narrow intercellular space, as in the
resin-containing canals of coniferous plants. There is a remarkable
external resemblance in the habit of the cactus-like Euphorbias,
which are a feature of the arid districts of tropical Africa, and the
Cacti which are associated with similar conditions in the deserts
of the Southern United States of America. But the presence of
the latex-containing cells of the Euphorbias supplies a distinctive
anatomical character. The number and position of the resin-
canals which are found in the stem and leaves of many conifers
are useful characters in the distinction of the species.

Many of these secretions are, from the point of view of the
plant, of the nature of waste-products. Owing to the fact that
plants do not perspire and have no kidneys, other ways of getting
rid of waste-products of metabolism have to be devised. These
products are set aside outside the sphere of metabolic activity, as
in the secretory vessels already mentioned, or are deposited in th^
bark which becomes gradually exfoliated, or in the leaves which
are ultimately thrown off. An interesting example, which also
affords characters of use to the systematist, is found in the Cysto-
litlis. These consist of local growths of the cellulose cell-wall
which become permeated with minute particles of carbonate of
lime. If treated under the microscope with a dilute acid the
carbonate is dissolved and decomposed, and we may watch the-
tiny bubbles of carbonic acid gas which are given off in the process.
The matrix remains as a delicate cellulose skeleton showing well-
marked stratification. Cystoliths are very common in two widely
separated families, Urticaceae (the nettle family) and Acanthaceae.
They were noticed in the former by Meyen in 1839 in the leaf of
the well-known India-rubber plant, Ficus elasiica. They occur
generally in the large genus Ficus (the figs), varying in form and

IN THE SYSTEMATIC STUDY OF THE HIGHER PLANTS. 359

size in different species ; and also in other genera of the family ;
and their relative frequency and form often afford useful specific
characters. The upper surface of the adult leaf is often rough
from the presence of the numerous cystoliths which occur as small
dots, or shorter or longer lines, or they may be curved.

In the family Acanthaceae also the form varies in different
genera and species. [

I should exceed the time at my disposal, and weary you into
the bargain, if I went into the subject of plant- hairs — a beautiful
and interesting microscopic study. As regards their distribution
from the point of view of the systematist I may quote the apt.
remark of De Bary, that the case is similar to that of the forms,
of foliage-leaves. On the one hand there is great uniformity in
the majority of species and genera of one family, at least as-
regards one characteristic form of hair, such as for instance the
stiff hairs of the Borage family, the short capitate hairs and scales,
of the Dead-nettle family, the star- shaped hairs of the Crucifers,
the tufted hairs of the Mallows and the three characteristic forms
of hair of most of the Hawkweeds. On the other hand, a great
variety of form may occur in the same family or even genus ; or
one characteristic form recurs in corresponding parts in the most
diverse families or genera, such as the stinging-hairs of the nettle-
family and of the widely removed family Loasaceae.

So far I have dealt with vegetative structure only, but the
special organs of the flower also supply minute characters whick
are useful for systematic purposes. I will refer briefly to one only,
viz. the characters of the pollen-grain. To some extent these are
obviously adaptive. In a few submerged aquatic plants, pollina-
tion, the transfer of the pollen from the stamen to the stigma of
the ovary occurs beneath the smiace of the water, and in these
cases the pollen sometimes takes the form of long threads.

In many plants the pollen is distributed by aid of air-currents^
and here the grains are very small and smooth, like fine dust, and
do not cling closely together ; in the pine the outer skin is blown
out to form a pair of air-bladders.

In flowers in which the pollen is transferred on some part of

the body of an insect which has visited the flower in search of

honey or pollen, the grains are sticky and cling together in smal^

masses. In these cases there is an extraordinary variety cf

f orm and external sculpturing of the grain, as to the meaning

•360 A. B. RENDLE ON THE USE OF MICROSCOPICAL CHARACTERS.

■of which we know little or nothing, and which might well form the
subject of a separate address. A certain form may be charac-
teristic of a family, as for instance the spiny pollen of the Mallows ;
or, on the other hand, a remarkable variety may occur in one and
the same family, as for instance in the Acanthaceae, where the
difierent genera show remarkably varied and characteristic pollen-
forms.

In the family Convolvulaceae the character of the pollen affords
a ready means of distinguishing genera that are otherwise closely
similar in characters of foliage, flower and fruit. Thus the genus
Ipomoea, the convolvulus of the tropics, which includes the Morn-
ing Glory and the so-called " Convolvulus major " of gardens, has
spiny pollen resembling that of the Mallows, whereas in the genus
Convolvulus, which includes our common bindweed, the pollen is
smooth. The series of lantern slides which follows shows on the
one hand a striking resemblance between the pollen of genera of
the same family, and on the other hand that there is often a remark-
able difference between the pollen-grains of allied genera ; the case
of the cornflower in the Compositae is an interesting illustration
of the latter.

In conclusion, it is obvious that the systematist may derive
great help from the study of minute characters, but it is equally
obvious that single characters must be used with caution, and this
warning applies not merely to those which can be elucidated only
by use of the microscope.

I should add that a large proportion of the lantern slides by
which I have been able to illustrate my address have been lent
me by my friend Dr. Rodman, our fellow-member, whose skill and
zeal in photomicrographic matters is well known to you.

Jorirn. Quekctt Microscopical Cltib, Ser. 2, Vol. ZIIl., No. 82, Aprii 191^.

361

ON SCHI8TOSTEGA OSMUNDACEA MOHR.

By G. T. Harris.

{Read March I2th, 1918; communicated by the Hon. Editor.)

Plates 23 and 24, and Figures 1-3 in Text.

This moss was originally described and figured by Dickson in
1785 (1), and named by him Mnium osmundaceum. Later, in
1803, Molir instituted the genus Schistostega for it, restoring
Dickson's specific name of osmundacea which had been super-
seded by Ehrart and by Hedwig (2). Sir J. E. Smith in his great
work on English plants (3) followed Hoffmann's lead of placing
it in Hedwig's genus Gymnostomum, presumably on account of its
gymnostomous capsule. Hooker and Taylor (4) accepted Mohr's
genus but adopted Hertwig's specific name of pennatum. Bridel
{5), Bruch and Schimper and Giimbel (6), Wilson (7) and Berkeley
{S) all adopted Mohr's nomenclature, and as Braithwaite (9) and
Dixon (10) among modern bryologists confirm these previous
authors by themselves accepting Mohr's genus it may be taken
that finality has at length been reached.

It is the only species of its genus and order.

The plant upon which Dickson's original description was based
was collected in Devonshire, in the much-quoted station " in
via ducente a vico Zele ad templum South Tawton, circiter 4
milliaria ab Okehampton, in comitatu Devoniae." As I know this
particular lane quite well I am able to state that it is just such a
locality as Schistostega best thrives in. Mr. W. P. Hiern, F.R.S.,
who has very kindly sent me Dickson's original description and
much information relative to its early history, writes, " The
collector was Sampson Newbery of Zele in the parish of South
Tawton., Devon." As late as 1830, the date of the seventh
edition of Withering's Arrangement of British Plants (11), only
Devonshire localities are given, viz. the one just mentioned, one

362 G. T. HARRIS ON

or two places near Totnes, and near Meavy parsonage. A note,
however, states that a new station had been recorded "by an
unknown friend in April 1826, Gallow's Hill in Nottingham
Forest." These localities correspond with those given by Braith-
waite, which are presumably arranged in chronological order,
and the " unknown friend " of Withering would appear to be
Jowitt. Withering confused Schistostega osmundacea Mohr and
PterygopJiyllum {=^ Hypnum) lucens Brid., a very different plant,
and attributed to this species the luminous appearance peculiar
to Schistostega as well as Bowman's station, Rowter Kocks,
Derbyshire. Since Newbery's day so many records have been
made that it is now known to be a widely distributed moss,
twenty-two county and vice-county divisions from Cornwall to
Stirling possessing it in the British Isles alone (23). The lane at
Zele is on the northern confines of Dartmoor, and Dartmoor may
be considered a centre of distribution for Devonshire, for among
its tors and rocks it is abundant and widespread. It would
appear to thrive best in granitic areas, as it becomes increasingly
rare in Devonshire beyond the influence of granite intrusions. It
is not infrequent around Silverton (12), north of Exeter, a district
invaded by the granite of Dartmoor ; in East Devon it is quite
a rare moss.

On Dartmoor it grows in narrow rocky crevices, principally
among the tors, in disused mine adits, and in old rabbit burrows
and fox holes. From very extensive observations of the habitats
on Dartmoor I have elicited the fact that these invariably face
north to east, while the moss itself in the majority of instances
occupies a position that gives it a northerly aspect. This observa-
tion is the result of the examination of dozens of localities on
Dartmoor in which compass bearings were taken. At my request
Mr. F. R. Rowley, F.R.M.S., of Exeter, noted the bearings of alt
the localities he found for this moss on Dartmoor during a month'&
holiday there, and found them to face north to north-east. An
area of Dartmoor in which this moss is particularly plentiful is.
the scarred and broken ground around the Vitifer tin mines.
In the old tin gullies that reach up nearly to the top of Birch Tor
rabbit burrows are so plentiful that "The Warren" is a local
appellation, and it gave me a very good opportunity of testing
the accuracy of the observation. In no instance did I find
Schistostega in a burrow facing south or west. One of the few

SCHISTOSTEGA 08MUNDACEA MOHR.

363^

places in East Devon where this moss occurs is in a large and
disused rabbit-burrow, near Sidmouth, which also faces north-
east. The most striking instance of the heliotropic adjustment
of this plant with which I met was in the neighbourhood of
Lydford on the western fringe of the moor, and as it is very"
illustrative of the habitat of this markedly heliophobic plant it
will perhaps be of interest if it is described somewhat fully. On
the north-western slope of Great Links Tor is an old stone hut-

BED0F5CH1ST0STEGA.

■"^^.-S^i^^j^iiuJi'^ rj .**■

6^

THE SHEPHEKD*^ HUT.

Scale 1 -.30.

called locally " The Shepherd's Hut," and of which a diagram is-
given (fig. 1 in text). It has been formed by hollowing out the-
ground underneath a huge block of granite which forms the roof ;
the walls are formed partly by the earth where it has been cut
away and partly by blocks of granite built up to support the over-
hanging slab. An opening of about three feet square on the north-
west side gives entrance to the hut or cave, which is more or les^
circular, with a diameter of about six feet and a present height

564 G. T. HARRIS ON

oi not more than four. The hut circle, for such it practically is,
while not in any way prehistoric is of very considerable antiquity,
and probably was constructed as a temporary dwelling, or cache,
by tin miners in the days of the tin-streaming industry, as old
iurrows are plentiful in the neighbourhood. As will be seen
-from the diagram, Schistostega occupies a position in the interior
on the south side of the bank of earth, where it faces due north.
Here it grew luxuriantly, and was fruiting abundantly at the
time of my visit. Now it is obvious that the part of the hut wall
to the left of the bed of Schistostega, being to westward, would
get less light, while that to the right would have considerable
illumination in the late afternoon owing to its facing north-west.
A careful examination of the area covered by the moss indicated
that its ecological optimum was at the position where it faced
north, as on either side its growth thinned off, on the one hand
into light of a low, and on the other into light of a relatively high
intensity. These mediaeval caches are not infrequent on Dart-
moor, more especially to the south of Princetown, and they are
almost always associated with a luxuriant growth of Schistostega
osmundacea.

From repeated photometric examinations by Wiesner's method
■(13) I have estimated the specific light-ration of Schistostega to
be l/50th of the total unobstructed light, but however carefully
■conducted they may be such estimates can only be an approxima-
tion to the actual light-ration of the plant. Wiesner's method
depends on the darkening of silver bromide paper to a standard
tint, and as the silver haloid used in the preparation of the sensi-
tive paper is principally sensitive to the blue- violet rays it follows
that a measurement of light made in the open with an abundance
of the more refrangible rays cannot compare satisfactorily with
A measurement made at a point where the light to which the
photometric paper is exposed has the blue-violet rays filtered out
to some extent by passing through a screen of foliage more or
less dense.

Small as the light-ration of Schistostega may appear, it is com-
paratively generous when compared with that of such a plant as
Aspidistra elatior, whose ration is only about l/200thof the total
•diffused light outside (14), and it should be remembered that the
chloroplasts of sciophilous plants are more sensitive to weaker rays
of light than are those of heliophytes (15). The striking bluish

SCHISTOSTEGA OSMVNDACEA MOHR. 365"

metallic lustre of many plants growing in deep shade is very
apparent in S. osmundacea, more especially in plants which are
vigorous in growth. Occasionally plants are met with that
approach in colour normal, or even slightly yellow, green ; but-
such plants are probably old or lacking in vigour, as strong,
healthy plants exhibit the glaucescent lustre in a very marked
manner. It is perhaps worth mention that one or two other
species of mosses are quite frequently found associated wdth
Schistostega, such as, for instance, Plagioihecium depressum
Dixon, Webera proUgera Bryhn, etc. ; and as these species grow
equally well in light of a far greater intensity, it points to the fact
of their having a considerable range of adaptation. Nor, so far
as I have been able to make out, does their association with
Schistostega in its feebly illuminated habitat entail any modifica-
tion of their structural details.

Schistostega is a sufficiently striking plant to make its identi-
fication quite easy when its habitat is once comprehended, and
Dixon has aptly described it as resembling miniature fronds of
Lomaria sficant. Individually it is 8-12 mm. in height and forms
beds several inches square, usually on the sides of the burrows-
and crevices in which it dwells, more rarely on the floors. It has
been frequently described as growing in ivet sandstone caves.
I have never yet found any plants of Schistostega in a locality^
that could with accuracy be described as wet ; on the contrary
it seems to avoid such spots. The Dartmoor localities, which
from its abundance and luxuriance may always be regarded as.
representing the ecological optimum of this plant, are by no
means wet ; in fact the absence of anything like coherence in the
soil upon which it is found growing makes it a very difficult plant
to collect satisfactorily, as it so readily becomes disintegrated
on detachment that the plants are lost amongst a handful of loose
earth. It would be more correct to describe its habitat as a damp
one. At the same time so good an authority as Mr. A. D»
Michael, F.L.S., has given a description (16) of a cave in Cornwall
he visited which was said to contain this moss. It is described
as a cave with dripping sides on the sea-shore, inundated by high
spring tides. The description of the greenish glow seen when
standing at the mouth of the cave is quite indicative of Schisto-
stega, but the statement that the same glow was apparent in the.
small pools on the floor of the cave scarcely suggests this moss.

566 G. T. HARRIS ON

I myself have never seen Schistostega in such a markedly mari-
time station. Mr. Michael adds that he collected some of the
growth both from the sides and from the pools, but found only
Diatomaceae. This, however, does not disprove the presence of
the moss, as its minute fronds are extremely delicate and would
easily be rendered unrecognisable in a heterogeneous mass of
material.

The fruit appears to be somewhat rare, though when fertile
the capsules are often produced in abundance. A great help
in the distribution of the plant is afforded by the extremely
deciduous nature of the capsule, brought about by the structure
figured in Plate 23, fig. 3, and which appears to have escaped the
notice of bryologists, as I have seen no reference to it in any
4iterature I have consulted. The perichaetium in Schistostega is
stalked, unlike the majority of mosses in which it is sessile ; the
proximal end of that portion of the seta bearing the capsule, and
which is the true seta, is bulb-shaped and composed of large
irregular cells. This bulb-like portion fits in the hollowed recep-
tacle of the vaginula, the whole forming a ball-and-socket arrange-
ment. When the capsule is mature the large spongy cells at the
base of the seta contract, causing it to fit so loosely in the vaginula
sheath that a very slight touch is sufficient to dislodge it. Quite
early in the life of the sporogonium, even before the rupture of
the venter, the ball-and-socket arrangement has already been
formed (Plate 23, fig. 4), and the seta may easily be forced away
from the vaginula by placing a cover-glass over a female plant
and applying a little pressure. Only one archegonium is present
in the female plant, and there are no paraphyses. A further aid
in the distribution of the plant is the presence of abundant
gemmae, which obviously are easily conveyed by the fur of rabbits
from one burrow to another. It is very curious that these
gemmae have hitherto escaped notice in this country. I myself
never noticed them in any gatherings until the autumn of 1917,
when I first found them abundant in some gatherings made on the
moor near Lydford, and correspondents who have at my request
specially examined their gatherings for their presence write saying
that they have failed to find any.

My observations suggest the conclusion that these gemmae
Are principally produced when barren conditions of the plant
prevail ; although they may be present in fruiting commuiuties.

SCHISTOSTEGA OSMVNDACEA MOHR. 367

they are so to a very much less extent. I have colonies of Schis-
tostega growing in captivity from various localities on Dartmoor
which rather confirm this view ; they are kept quite separate and
are all extremely healthy and vigorous. One colony is, and has
been since it was first collected, quite barren, but produces an
abundance of gemmae ; another in the spring of 1917 was covered
with capsules and at the present time is again covered with ripening
capsules, but gemmae are very infrequent. Such a correlation is
repeatedly met with among mosses, as for instance the deciduous
leaves in barren states of Campylopus pyriformis, Brid., which
condition is scarcely developed when the plant is fertile. These
gemmae are multicellular, club-shaped bodies of about 100/x in
length produced from the distal end of a filament of the protonema
by a cell becoming enlarged and ultimately separating itself
from the parent cell by the development of a separation cell
(Plate 23, fig. 5). A new protonema may be produced by budding
from one of the cells of the gemma (Plate 23, figs. 6, 7) ; or in
rare instances the gemma may produce another gemma without
the production of protonemal growth (Plate 23, fig. 8). These
gemmae secrete a material of great adhesive power by which they
become attached so firmly to foreign bodies that some force is
necessary to dislodge them. Apparently the mucilage is excreted
by the cells at the distal end of the gemma, as I have never seen
one affixed by any other part of the bud. Yates has called atten-
tion to a similar phenomenon among the Hepaticae (17).

It is the protonema of Schistostega that gives it the great
interest it possesses for the biologist, and which is probably unique
in the vegetable world in its highly developed system of photo-
synthetic cells. Bowman quite early in the history of the plant
gave a description of the convex light-cells and their function (18) ,
and of late years much work has been done on them principally by
Noll (19) and Vuillemin (20) . The protonema is generally regarded
as persistent, unlike the majority of mosses in which it disappears
on the establishment of the plant, but I do not think that it can
be regarded as essential to the life of the adult plant, for in those
colonies I have growing in confinement it is reduced almost to
extinction when the plants are full grown. One has to remember
that a patch of Schistostega usually contains all stages of growth
simultaneously, and my examination of such patches leads me to
^»7fer that it is the younger portions of the colony that produce

368 G. T. HARRIS ON

the protonema with its differentiated light-cells, for in one part a
thick mat of protonema and young plants may be seen while a
contiguous patch of adult plants bearing capsules may be practic-
ally without any protonema. The function of the protonema
being the protection and nourishment of the bud in its early
stages, it would obviously not be required when the plant was
able to maintain itself ; and as the adult plant of Schistostega
produces an abundance of rhizoids which fix it independently to
the soil, the necessity for the existence of the protonema ceases.
As far as the adult plant is concerned the protonema is certainly,
in a strict sense, not persistent, but it may always be in existence
in some part of the colony. It is undoubtedly a very variable

lit'''

Photo-synthetic s\|8tem d li^htcelb.
( AJterNoll.)

production. In some instances I have had thick felted masses of
bi pinnate threads, as shown in Plate 23, fig. 9, with practically
no light-cells ; in other growths the light-cells predominated, and
the simple bipinnate stage is probably the early stage of the
photo-synthetic system, as I have had whole masses which
exhibited the light-cells arranged in a beautiful bipinnate manner.
Noll has given a figure of the protonema which shows it as a
dendroid structure, the light-cells being arranged in two flat
tables one on either side of an upright stem, which arises from a
basal protonema (Fig. 2 in text). I have never seen anything so
regular and symmetrical as this figure of Noll's indicates. Usually
the photo-synthetic system, although elevated above the basal

SCHISTOSTEGA OSMUNBACEA MOHR. 36^

protonema, is spread out in an irregular superficial series of cell&
of greater or less extent.

In examining the protonema of Scliistostega one cannot fail to
be struck by the nodular condition (Plate 23, fig. 10) the cells
assume, even when they do not develop into the advanced stages
shown by the flask-shaped and obconical light-cells. It would
appear that any cell is capable of producing a distension that may
ultimately become either a flask-cell or a light-cell. The flask-
cells were first noticed by Correns (21), who described them as a.
form of gemma. Later Grout (22) called attention to them as.
existing in gatherings of Schistostega made in America. I have
frequently met with them in my own gatherings, and at first,,
influenced by the views of Correns and Grout, I regarded them
as a form of gemma. This, however, they are not ; being merely
the separation cell remaining after the liberation of the true
gemma. Fig. 11, Plate 23, shows one of these flask-cells remaining,
attached to a portion of the protonema filament, but occasionally
the entire filament seems to be given up to the production of the.
gemmae, as may be seen from a consideration of fig. 1, Plate 24^
in which numerous separation cells are shown from which the
gemmae have fallen ; at -4 a gemma is forming by enlargement of
the distal cell, and B shows the initial stage in the production of
a flask-cell. It is interesting to note that the globose base of the
flask-cells which bear the gemmae often produce the characteristic
bowl-shaped chloroplast, as will be seen on reference to Plate 23^.
fig. 11, A, and again in Plate 24, fig. 1. c. There appears to be
no stability in the form of any of the variously shaped cells to be
found in the protonema. The narrow elongated cells may bulge
at some point and a light- cell be produced, which may elongate
and form a flask- cell, to give rise eventually to a gemma. One
of the marked features of all the cells connected with the proto-
nema is the large size and heliotropic arrangement of the chloro-
plasts, even when single and not bowl-shaped as in the light-cellsw
Braithwaite incorrectly describes the protonema as " composed
of globose cells void of chlorophyll," and gives a figure that very
poorly represents the actual structure. He also figures the leaf-
cells as filled with minute grains of chlorophyll, whereas the
chloroplasts are quite noticeably large and comparatively few in
number, being oval and round and about lOyw. in diameter. The
cell itself is about 1/50 mm. in thickness, and the chloroplasts are
JouRN. Q. M. C, Series II.— No. 82. 28

370 G. T. HARRIS ON

arranged principally on each surface of the cell wall (Plate 24,
fig. 2). As the distichous leaves of the adult plant are set vertic-
ally on the stem, and as the stem grows usually at right angles to
the incident light, the edge of the chloroplast is consequently
presented to the action of light, though it would seem that a
certain amount of translocation takes place, as many of the
■chloroplasts may be seen ranged along the side walls of the cells,
in which position the whole surface of the chloroplast would be
exposed to the action of light.

The light-cells themselves are obconical in shape and of about
30/Jt X 20/>t when at their maximum growth. They are produced
from the end of a filament by a process of budding, and as previously
mentioned they often assume a more or less regularly pinnate
growth, and form a superficial aggregate of considerable size.
They may on the contrary be sparingly developed and scattered
singly or in small groups among the filaments. The distal portion
•of an ordinary linear cell becomes swollen and the chloroplasts
■become much enlarged, the next cell in series, produced by
budding, is shorter and more globular ; eventually the cells become
quite globular and assume the ideal obconical form. Lateral
bidding takes place later until eventually the superficial aggregate
is^^formed, Plate 24, fig. 3. The chloroplast of the ideal light-cell
is bowl-shaped and fills the conical bottom of the cell to about
one-third of its height as shown in fig. 4, Plate 24, where the
obconical cells are shown in vertical section. Bowl-shaped
<5hloroplasts are of frequent occurrence in the genus Anthoceros
i( Liver worts), they also occur in Selaginella martensii, but they
probably are nowhere developed to such a state of efficiency as in
the photo-synthetic system of Schistostega. In its most perfect
form, which may be described as the " rosette " form, it consists
of six wedge-shaped chloroplasts arranged in a circle around a
seventh, which is central and lies at the bottom of the obconical
oell. This ideal " rosette " chloroplast is seen in cell 5, fig. 3,
Plate 24. It will be seen that a highly efficient photo-synthetic
-cell is produced by the obconical shape with the bowl-shaped
■chloroplast filling the conical base, their separate pieces so arranged
as to present a uniform sheet of chlorophyll to the light condensed
.-by the convex portion of the cell. On the budding of a new light-
•cell from a parent cell one or more chloroplasts pass into the new
J3ud before it is separated from the parent (Plate 24, fig. 5), and

SCHISTOSTEGA OSMUNDACEA MOHR. 371

this chloroplast appears to enlarge by subsequent growth until it
assumes a plate-like form, when it divides to form the " rosette "
shape (Plate 24, fig. 6). In Plate 24, fig. 3, cell number 3 will
be seen to contain a single " rosette " bowl-shaped chloroplast
and several unassociated and irregularly shaped chloroplasts,
one of which will pass into the new light- cell seen to be in process
of forming at A. The light-cell with the " rosette" chloroplast
is undoubtedly the ideal cell of the system, but the " rosette "
shape is not always produced, it is frequently replaced by
irregularly shaped chloroplasts which are also bowl -shaped.
Cell 13 in fig. 3, Plate 24, shows a frequent type of irregular chloro-

Fig. 5.
CiaqTam of \\g\\i rays in ob-coiiicai cell.

(After Noli.)

plast formed of four roughly triangular portions with their
apices forming the bottom of the bowl. In som^e cases numerous
large circular chloroplasts aggregate in an irregular manner at
the bottom of the cell, but whether these combine and eventually
form a " rosette " I have not been able to determine. It is, of
course, these cells that produce the peculiar luminous appearance
for which Schistostega is knovv^n, and Noll gives the following
explanation (19) — " The rays of light which fall upon the cell are
refracted and concentrated upon the chlorophyll grains. Owing
to the shape of the cell the rays are totally internally reflected from
the basal walls of the cells and are again emitted, which gives the

372 G. T. HARRIS OX

luminous appearance" (fig. 3 in text). Haberlandt states tHat "the
chlorophyll apparatus in each funnel-shaped cell is so brilliantly
illuminated that it acts against a dark background as a self-
luminous body, any rays that are not absorbed by the chloroplasts
being reflected and retraversing the whole optical system contrary
to their path of entry" (24). When examining the "rosette"
chloroplast with a high power I have noticed its surface to possess
a decided burnished appearance. The researches of Guilliermond
(25) would suggest that this is due to the pigment of the chloro-
plasts having assumed a crystalline state, and it will be seen that
a highly crystalline state of the concave surface of the chloroplast
would practically convert it into a parabolic reflector and explain
in a large measure the green effulgence noticeable when looking
at a bed of this moss. One remarkable feature of the light-cell
producing portion of the protoneraa is the great variety of shape
the chloroplasts assume in the effort of dovetailing together to
form an unbroken surface of chlorophyll for the light to act upon.
Cells number 1 and number 2 in fig. 3, Plate 24, well represent this
dovetailing arrangement, which appears not to exist to the same
extent in those parts of the protonema not directly connected
with the production of light-cells.

My thanks are due to several who have generously given me
help in the preparation of this paper. Mr. W. P. Hiern, M.A.,
F.R.S., very kindly transcribed and sent me much informa-
tion relative to the discovery of the moss in Devonshire and its
early history. Mr. H. N. Dixon, M.A., F.L.S., was good enough
to look up and send me references to the literature dealing more
especially with the morphology of the plant ; while my friend,
Mr. F. R. Rowley, F.R.M.S., of Exeter, generously devoted part of
his holiday on Dartmoor to investigating the orientation of such
beds of Schistostega as he came across. I have again to thank
the Quekett Microscopical Club for extending to me the hospitality
of its Journal.

Literature Cited and Consulted.

1. Dickson, H. S. Fasciculus Plantarum Cryftogamicarum

Britannae, 1785.

2. Hedwig. Descrifiio et adwnhratio Muscorum frondosorutn,

fol. 1787-1797.

SCHISTOSTEOA OSMUNDACEA MOHR. 373

3. Smith, Sir J. E. Flora Britannica, 1804.

4. Hooker and Taylor. Muscologia Britannica, 1818.

5. Bridel. Bryologia Universa, 1826-1827.

6. Bruch, Schimper and Gumbel. Bryologia Europaea, 1836-

1855.

7. Wilson, W. Bryologia Britanniea, 1855.

8. Berkeley, M. J. Handbook of British Mosses, 1863.

9. Braithwaite, R. British Moss Flora, 1880-1905.

10. Dixon, H. N. Student's Handbook »f British Mosses, 2nd ed.

11. Withering, W. Arrangement of British Plants, 7th ed., 1830.

12. Savery, G. B. The Mosses of Silverton, Proceedings of

The Devonshire Association, xlii. pp. 391-412, 1910.

13. Wiesner, J. Der Lichtgenuss der Pflanzen, Leipzig, 1907.

14. Blackman, F. F. Notes on Recent Physiological Literature.
XL Illumination and Vegetation. The New Phytologist,

Vol. 6, 1907.

15. Warming, E. Ecology of Plants, Oxford, 1909.

16. Michael, A. D. Science Gossip, Vol. 13, p. 210, 1877.

17. Yates, H. R. Distribution of Hepatics. New Phytologist,

Vol. 7, 1908.

18. Bowman, J. E. Loudon's Magazine, Vol. 2, p. 406.

19. Noll. Ueber das Leuchten von Schistostega osmundacea.

Arbeiten aus dem botanischen Institut zu Wiirzburg, 1887.

20. VuiLLEMiN. L'appareil reluisant du Schistostega osmundacea.

Journal de Vanatomie et de physiologic. Vol. 23, 1887.

21. CoRRENS. Untersuchungen iiber die Vermehrung der Laub-

moose, Jena, 1899.

22. Grout. Rhodora, September 1902. •

23. A Census Catalogue of British Mosses, York, 1907.

24. Haberlandt, G. Physiological Plant Anatomy, Macmillan,

1914.

25. GuiLLiERMOND, A. CoMftes Rendus, clxiv. (1917), pp. 232-5.

26. Strasburger, E. Textbook of Botany, Macmillan, 1912.

27. Hodgetts, W. J. Vegetative Production of Flattened Pro-

tonema in Tetr aphis pellucida. New Phytologist, Vol. 14,
1915.

28. West, W. Luminosity of Schistostega. Naturalist, No. 256,

1907.

29. Haberlandt, G. Die Lichtsiimesorgane der Laubblatter.

Biog. Centralblatt, 1907.

? 5
5?

374 G. T. HARRIS ON SCHISTO&TEGA OSMVNDACEA MOHR.

30. Haberlandt, G. Zur Physiologie der Lichtsinnesorgane der

Laubblatter. Jahrh. fur. wiss. BoL, 1909.

31. Wager, H. Perception of Light in Plants. Annals of

Botany, Vol. 23, No. 91, July 1909.

32. ScHiMPER, A. F. W. Plant Geographij. Oxford, 1903.

Description of Plates.

Plate 23.

Fig. 1. Schistostega osmundacea Mohr. Fertile plant, x 16.

,, 2. Distal end of protonema producing gemma, x 300.

3. Perichaetium showing ball and socket arrangement, x 35-.

4. Immature seta and calyptra. x 35.

5. Gemma with separation cell, x 300.

6. Gemma producing protonema. x 300.

7. Gemma producing protonema. x 300.

8. Gemma producing new gemma, x 300.

9. Bipinnate arrangement of protonema. x 200.
,, 10. Nodular condition of protonema. x 300.

,, 11. Flask cell, with " rosette " chloroplast at A. x 300.

Plate 24.

Fig. 1. Protonema with flask- cell s : A. budding gemma;
B. early stage of flask cell ; C. " rosette " chloroplast
in base of flask-cell, x 300.

2. Cells of leaf with chloroplasts. x 510.

3. Photo-synthetic system with chloroplasts. A. budding
light-cell. X 510.

4. Bowl-shaped chloroplasts in light-cells, ver. sec. x 510.

5. Budding light-cell with migrating chloroplast at A. x 510.

6. Four light-cells showing various stages in the division
of the chloroplast from a simple plate-like form com-
mencing division to the bowl-shaped chloroplast of four
pieces, x 510.

,, 7. Bud of new plant arising from protonema. x 300.

Figures in Text.

Fig. 1. Plan of " The Shepherd's Hut," Dartmoor.
,, 2. Photo-synthetic system of light-cells (after Noll).
,, 3. Diagram of light-rays in obconical light-cell (after Noll).

Jiiurn. Quckitt ilicroscojncal Club, Sir. 2, Vol. XIII., No. 82, AprU 1918.

J)

n

JOURN. Q. M. C.

Ser. 2, Vol. XIII., PI. 23.

G. T. Harris, delin. ad nat.

SCHISTOSTEGA OSMUNDACEA Mohr.

JOURN. Q.M.C.

Ser. 2, Vol. Xlll., PL 24.

(r. T. Harris, delin. ad nat.

SCHISTOSTEGA 0SMU2^DACEA Mohr.

375

LEBER Tl A SEFVEI WALTER.

By W. Williamson, F.L.S., F.R.S.E., and Charles D. Soar,

F.L.S., F.R.M.S.

{Read March I2th, 1918.)

Plate 25.

Among the species of Lebertia, two, L. giardinai Maglio * and
and L. sefvei Walter, f niay be readily distinguished from the
other members of the genus. This is due to the fact that they
have the genital area enclosed by the fourth pair of epimera.
The first of these was found in Italy and has the genital area in
the male completely surrounded, while in the female the rounded
inner posterior corners of the fourth pair of epimera come very
close together behind the genital area, but do not quite meefe..
The second was found in Swedish Lapland, and differs from the
former in that the fourth pair of epimera are separated by a
narrow strip extending from the genital area to the rounded
posterior margin. It may also be noted that in L. giardinai
the spines of the palpi are pectinated, and that the inner ex-
tremities of the second pair of epimera end in a point, while in
L. sefvei the spines of the palpi are not pectinated and the inner
ends of the second pair of epimera are broad.

The discovery of the Arctic form in Dartmoor brings the
number of the Britannic species up to twelve.

L. sefvei belongs to sub-genus Hexalebertia and in length is a

* Maglio, Rend. Ist. Lombardo, Ser. II. xli. 3 ; Atti. Soc. Ital. Sci.
Nat. Pavia, xlviii. 274-277, figs. 12-13. Monti, Atti. Soc. Ital. Sci.
Nat. Pavia, xlix. 59-61, figs. 51-54.

t Naturunssenschaftliche U titer suchungen des Sarekgebirges in
Schwedisch-Lappland, Bd. IV. 598-60, PI. 9, figs. 11-13. (C. E.
Fritzes Bokforlags- Aktiebolag — Stockholm. )

376 W. WILLIAMSON AND CHARLES D. SOAR ON

little over 0'7 mm. and about 0'4 mm. in breadth. In outline
it is elliptical, broadly rounded at both ends. Between the
antenniform bristles, it is slightly emarginate. The legs are
yellow, the body colour darker with brownish patches on the
dorsum. The skin is covered with short ridges of unequal length,
those on the anterior half of dorsum, particularly between the
•eyes, being very short. As the ridges get nearer to the posterior,
they increase gradually in length. Along the dorsum the direc-
tion is longitudinal, but as they pass round to the ventral area
posterior to the epimera, the direction of these ridges becomes
transverse. They are slightly sinuate and free from one another,
•exhibiting between them an indistinct porosity of the skin. The
gland pores are encircled by a broad chitinous ring, but they do
not stand out prominently from the surrounding area.

The capitulum is a little over 0'2 mm. in length, and lies in a
long narrow bay formed by the first pair of epimera. The anterior
processes are almost parallel, and both they and the posterior
pair end in a sharp point. Seen from the side the ventral wall
of the capitulum is bent somewhat in advance of the posterior
processes. The ventral surface of the pharynx near to the
thickened posterior is also seen to be bent.

The palpi are about 0*3 mm. in length. The second segment
is stout and has its extensor surface well arched, with three
moderately long spines midway, and two longer ones distal.
The flexor surface is weakly concave with the long straight bristle
not quite distal. The third segment has the six long bristles
-disposed similarly to L. stigmatifera Sig Thor. {Zool. Anz.y xxxii.
151, fig. 876). The flexor surface of the fourth segmerit is
.almost straight, while the extensor surface is slightly curved,
giving the segment the appearance of being tapered a little. At
the distal end of the extensor surface there are four fine hairs.
The minute hairs on the flexor surface are rather nearer to each
other than to the ends of the segment.

The epimera are the prominent feature of the species and
almost entirely cover the ventral surface. The posterior ends of
the first pair end in a sharp point, and lie rather more towards
the genital area than the capitulum. The posterior ends of the
second pair are broad. The inner suture between the second
and third pairs is drawn in towards the first pair. The third
pair are triangular, the suture between them and the fourtlj

LE BERT I A 3EFVEI WALTER. 377

pair extending inwards for about three-fourths of the breadth.
The outer margins have two or three long hairs. The fourth
pair cover more than half the ventral surface and extend round
the sides well beyond the third pair. The genital area is enclosed
by them except for a narrow strip on the posterior median line.
The fourth pair have the posterior margin well rounded towards
the sides.

The first pair of legs are about 0"5 mm. in length ; the second
pair 0"6 mm. ; the third pair 0*7 mm., and the fourth pair a little
over 1 mm. The second, third and fourth segments of the first
pair of legs have each one broad pectinated spine at the distal
end while in addition the second and third segments carry a few
short curved spines. The fourth and fifth have a few rudimen-
tary hairs. Bristles are apparently confined to the third and
fourth segments, which have one each distal. The first and
second segments of the second pair of legs have each one long
thin spine distaL The third and fourth segments have the distal
ends fringed with broad pectinated spines, the largest being on
the flexor surface. The fifth and sixth segments resemble those
of the first pair of legs. The first four segments of the third
pair of legs resemble those of the second pair, but with more
numerous spines. The first segment of the fourth pair of legs
has six or seven spines for the most part clustered at the distal
end of flexor surface, and where it articulates with the second
segment there are a few fine hairs. Distal spines of second and
third segments short and pectinated. The spines on all the
segments of the fourth pair of legs are relatively more slender
and straighter than on the other legs. The fifth segment has a
few fine spines and several fine hairs. Swimming hairs are either
wanting or of a very rudimentary character.

As indicated above, the genital area is surrounded by the
fourth pair of epimera, except for a narrow strip. In outline it
is pyrif orm, with the usual anterior and posterior ridges for muscle
attachment, which, however, do not appear to be linked up to
the epimera. The posterior pair of acetabula are slightly smaller
than the other two pairs. Along the inner edge of each valve
there are about twenty hairs.

The anus is surrounded by a strong ring and has on each side
a gland pore.

A single specimen of which the sex cannot be determined was

378 W. WILLIAMSON AND CHARLES D. SOAR.

taken by Mr. D. J. Scourfield at Fernworthy Bog, Dartmoor, in
August 1917.

Description of Plate 25.

1. L. sefvei Walter, Ventral surface.

2. L. sefvei Walter, Inner side of left palp.

3. L. sefvei Walter, Fourth leg.

Jouut. Qufkfii Microscopical Club, Scr. 2, Vol. XI If., Ao. 82, April 1818.

JOURN. Q. M. C.

Ser. 2, Vol. XIII., PI. 25.

C. D. Soar, delin. ad nat.

Lebertia sefvei Walter.

379

NOTES.
ON THE MEASUREMENT OF MAGNIFYING POWER.

By Edward M. Nelson, F.E.M.S.
{Read in title, January Sth, 1918.)

The first duty of every one who lias purchased a microscope is ta
determine the combined magnifying power of its various object-
glasses and eye-pieces. The first three extras to be purchased
should be a stage micrometer, a micrometer to drop into an eye-
piece, and some sort of camera for drawing. The cost of these
being about 6s. each, the outlay required is small, but it should
be known that these three things are " essentials " if real micro--
scope work in any branch is to be undertaken.

On a previous occasion (June 24th, 1913) I brought to your
notice a method of measuring the magnifying power of a micro-
scope, June 1913 (Ser. 2, Vol. XII., No. 73, p. 239), and now I
propose to lay before you a better plan.

As the measurement of the various objects upon which one is at
work is a most important microscopical duty, it is necessary to-
know the value of the divisions in the stage micrometer in terms
of the eye- piece micrometer. These values for all the objectives
in the microscopist's battery should be entered on a card and
kept with the microscope in its box. This is the simplest of all
microscope measurements, for it consists merely in finding out
how many divisions of the eye- piece micrometer are required to
span O'l mm. on the stage micrometer. When these values are
known the size of any object can be at once calculated. I have
published a small table * to save the microscopist the trouble
of this calculation. In that table these values, viz. those of the

* Micrometric Table by Edward M. Nelson. H. F. Angus & Co,,.
83, Wigmore St., London, W. (1914). 3d.

380 NOTES.

stage micrometer in terms of the eye-piece micrometer, are called
M, so we will continue to represent them by that letter.

The determination of the combined powers of a battery of
•object-glasses with various eye-pieces is a tedious business.
There are various ways in which it may be done ; one is by
projection in a photomi orographic camera ; another, and more
usual plan, is by means of a simple form of camera, such as a
WoUaston's camera or Beale's neutral tint, to cast down the
image upon a divided ruler ; these methods are so well known
that further description is unnecessary. The new plan is as
follows : After having found the value of M for each objective
in the battery, one object-glass is selected (preferably one of
medium power, say 1/2-inch), and by one or other of the above
methods the combined magnifying power of this object-glass with
All the eye-pieces is carefully measured. These measurements
are then divided by the M value for that object-glass. This
gives a constant for each eye-piece. The combined power of
any other object-glass with any eye-piece whose constant is
known is found by multiplying the constant of the eye-piece by
its M value.

I have just arranged a battery of twelve object-glasses and
four eye-pieces with a microscope for work on pond life. The M
values of the object-glasses were carefully measured, the com-
bined power of one object-glass, the 1/2-inch, was also measured,
these data gave the constants of the eye-pieces, then the com-
bined powers of the remaining eleven object-glasses with the four
«ye-pieces were read ofi a slide rule, at sight, without any trouble
at all. Example :

Eyo-pieces .

. No. 1.

No. 2.

No. 3.

No. 4. M.

Constants

. 8-77

12-68

14-90

20-09

Objective, 1/2-inch

. 103

149

176

230 11-75

Objective, 1/G-inch

. 290

420

500

070 33-33

Here 103 di\dded by 11-75 is equal to 8 '77, the constant of No. 1
«ye-piece ; this constant 8-77 multiplied by 33-33 gives 290, the
power of the l/6th with No. 1 eye-piece, and so on.

Perhaps some would prefer the reciprocal method ; for neces-
sarily the result is the same whether a number is multiplied by
another or divided by its reciprocal. The following example will
explain.

NOTES. 381

Divide 100 by M, which will give the value of one division of
the eye-piece micrometer in micra. This is useful where the
measurement of any object is some simple number of eye-piece
divisions.

With the same 1/2-inch we have 100/1175 = 8*51 micra. There-
fore if any object spanned two or three divisions its size is known
at sight. (The card of magnifying powers, which I put in the
box of the new binocular, has both M and 100 times its reciprocal
given, the tube length being 211 mm.) To find the constant
of the eye-piece : The combined magnifying power of this objec-
tive and each eye- piece must be multiplied by this quantity 8 '55 ;
thus for No. 3 eye-piece we have 175 x 8*51 = 1,489, the constant.
If this constant be divided by the value of an eye-piece division
in micra for any other objective it will give the combined magni-
fying power; thus for the l/6th object-glass where 100/ilf = 3 •Q-
we have 1,489 divided by 3*0 = 500 as before.

The systems are the same, except that division is substituted
for multiplication and vice versa. As division is arithmetically
more laborious than multiplication, this system is hardly so con-
venient as the other, but when logarithms or a slide rule is used
there is no difference between them.

CARL DIETRICH AHRENS.

{Died March, Uth, 1918, aged 81.)

With the death of Mr. CD. Ahrens * a notable worker in the-
optical and microscopical worlds has passed away. By trade he
was a prism and spar slitter. He made Nicol prisms and analysers^
quartz and calcite prisms of all kinds, as well as the glass prisms^
for Wenham binoculars. In 1867 he designed a binocular upon
quite a novel plan. The rays issuing from the back of the objec-
tive were separated to an angle of 15° by a double-image calcite
prism ; these rays were then crossed over by two flint prisms, to-
correct the chromatic dispersion. The rays used were the extra-
ordinary, the ordinary being diverted out of the path. The tubes-
were equally inclined to each other. He says that " the plan
may not be so good as the Wenham for low powers, but for high.

* Ahrens was bom in Hanover in 1837, and as it had not then been*
ceded to Germany, he was by birth a British subject.

382 NOTES.

powers I cannot conceive anything finer." It also formed a
binocular eye-piece and was about the first to be made. In 1881
lie introduced another new binocular, in form like Stephenson's.
It had parallel tubes, but they were bent as in the Stephenson.
The ingenious part of the arrangement was that the beam from
the back of the objective was divided by two Wollaston camera-
lucida prisms placed back to back ; these deflected the rays right
and left, then another prism with two reflections bent them up
the tubes. Probably a carefully made binocular on this plan
would be a very successful instrument. In 1884 he designed a
bent-tube erecting monocular microscope ; obviously a most
useful instrument, it is surprising that some energetic manu-
facturer has not taken up this idea.

In the same year he designed a new polarising prism which was
further improved by Mr. H. G. Madan in 1885. In 1886 he brought
out yet another improved form of polarising prism, the object of
which was to lessen the ratio of its length to its breadth. That of
the Nicol is about 3:1, while the Ahrens was IJ : 1. In 1887 he
made an erecting microscope the design of which has had far-
reaching consequences. The erection was obtained byPorro prisms.
A description of this instrument, with figure, appeared in the R.M.S.
Journal for 1888, p. 1020, fig. 161. He said that " the erection
of the image is obtained by two right-angled prisms crossed in the
way used in some of the binocular field glasses." This naturally
came to the notice of Mr. J. W. Stephenson, the treasurer of the
E.M.S., who was especially interested in binoculars and prisms
of all sorts. He applied to Ahrens and asked if he could supply
him with one of these binocular field glasses. Ahrens replied
that they were difficult to make and would cost some £25. Mr.
Stephenson thought this too high a price, and wTote to Prof.
Abbe, with whom he was in frequent correspondence, to ask if
the Zeiss firm would send him a quotation for a pair of these field
glasses. This letter of Stephenson set Prof. Abbe on the subject,
and 80 was the cause of the introduction of these wonderfully
useful glasses. (It is not at all unlikely that Porro got the first
idea of erection by two right-angled prisms from Zahn's Oculus
Artificialis, a book published in 1702, where there is a figure of a
telescope doubled up in a similar manner by right-angled reflecting
mirrors). It was Ahrens, however, who first brought the long-
forgotten Porroprism to remembrance. The difliculty in the con-

NOTES. 383

struction of a prism binocular field glass was at that time little
understood, and has not been as yet pointed out in any treatise
on optics. The curves of the objectives must be altered so as to
balance the undercorrection caused by the prism. Prof. Abbe saw
that this undercorrection was fully compensated for, and there-
fore the^e glasses were from the first a great success. Now with
regard to the Greenough binocular. The twin microscope bino-
cular was invented by Pere Cherubin d'Orleans in 1677, but as
the microscopes were of the ordinary inverting form the image was
pseudoscopic. To remedy this, erecting eye-pieces of Eheita's
pattern were added; these certainly changed the pseudoscopic
vision to orthoscopic, but owing to the great increase in the length
of the body the inclination of the tubes to one another was so
much reduced that very little stereoscopism was left in the image.
A twin-microscope binocular must have short bodies, and it was
this microscope of Ahrens which made the twin-microscope
binocular a practical instrument.

Edward M. Nelson.

Another link with the past has just been broken by the death
of Carl Dietrich Ahrens at the ripe age of eighty-one. A skilled
handicraftsman with a distrust of all machinery for the doing of
his beloved work, he was a typical representative of the pioneer
artists who so often labour so diligently to lay the foundations
of a new industry, only to find that the more successful their
work, the more unnecessary their own activities ultimately
become, as labour-saving machinery is introduced to meet the
demands their own work has created.

Ahrens' best work was undoubtedly done in the making of
the large Nicol prisms which have been so closely identified
with his name for the last half-century. At such work he was
an artist. Possessing but a very limited amount of theoretical
knowledge, his instinctive knowlege of the optical ejects of
Iceland spar, quartz and other double-refracting media, when
€ut and combined in various ways, was wonderful; and no one
had quite the success in the important operation of cementing
such prisms that he had. For many years, in fact until just
before his death, the cement employed by him was kept as a
great secret. It is now known, however, that he used nothing

384 NOTES.

more than gum copal dissolved in turpentine. It is open to
question, however, whether the good results that he obtained
were not, in the main, due rather to the extreme care taken in
the process than to the cement itself. A fine pair of prisms
representing Ahrens' best work, with an aperture of about
3 J inches, have fortunately been secured for the Science Museum^
South Kensington, together w^ith a fine collection of projection
preparations for the prisms. Ahrens did a great deal of work
besides that already referred to. As time advanced, however,
he had it borne upon him that the demand for his work was-
decreasing. The various optical elements upon which he had
Bpecialised became ultimately in such great demand that the
introduction of machinery for their manufacture was called for.
Then Ahrens discovered, to his sorrow, that his erstwhile cus-
tomers preferred to go abroad for these optical appliances,
where they could obtain them cheaper and probably better made.
Personally Ahrens w^as a man of strong and independent
character — strictly honest in all his dealings, and, poor though
he was, autocratically selecting his own customers. His death
leaves a vacancy which it will be difficult to fill.

Frederic J. Cheshire.

385

PROCEEDINGS

OF THE
QUEKETT MICROSCOPICAL CLUB.

At the 527th Ordinary Meeting of the Club, held on October 23rd,
1917, the President, Dr. A. B. Rendle, M.A., F.R.S., F.L.S., in
the chair, the minutes of the meeting held on June 26th were
read and confirmed.

Mr. Alfred W. Alabaster was balloted for and duly elected a
member of the Club. Nomination forms for six others were read
for the first time.

The President informed thos§ present that the committee had
decided, until further notice, to hold the Ordinary Meetings on
the second Tuesday in each month instead of on the fourth, the
" Gossip" Meetings being held on the fourth Tuesday.

Dr. G. H. Rodman, F.R.P.S., then gave a lantern demonstration
of photomicrographs. In a short introductory address he said
he considered it a great compliment to be asked to give his demon-
stration and to address the opening meeting of the fifty-third
session of the Quekett Microscopical Club. He was more accus-
tomed to address photographic societies than practical micro-
scopists of such repute as the Quekett Club contained. He
wished to bring forward a plea for recording by photography the
magnified images of objects as observed on the microscope stage.
The photographic plate reveals a great deal, and if given the
opportunity will render a satisfactory picture, as well as record
truthfully what is made evident by the microscope. The photo-
graphic camera has a keener eye than a human being. He had
sometimes found whilst developing a plate that a spot appeared
which gave him considerable anxiety, but when the process was ,
completed it turned out to be a true record of some detail which
had been and might have been easily overlooked by anyone
using the microscope only in the ordinary way. As an illustra-
tion of the greater sensitiveness of the photographic plate as

JouRN. Q. M. C, Series II.— No. 82. 29

386 PROCEEDINGS OF THE

compared with the human retina, the lecturer said a photograph
might be taken of a quickly moving vehicle, such as a dog-cart,
when on the plate the spokes of the wheels would all be distinctly
evident and well defined, but to an observer's eye they would
present nothing but a blurred and indistinct view. The use of the
camera lucida for securing representations of the magnified image
and some of the difficulties of its employment were then referred
to. It was remarked that in the hands of such an expert as
TufEen West the results were excellent, but the personal factor
•comes in strongly in the use of the instrument, and not infre-
'quently the resultant drawing is a representation of what the
observer thinks he sees, or has seen represented elsewhere, rather
than of what is actually present. The chief objection usually
found in the photograph is the lack of depth of focus, but this
can be supplied to a great extent by the use of a Davis's shutter
behind the objective, cutting down the aperture of the objective ;
in fact, dealing with the micro-objective in the way that a
photographer would stop down his lens, say, to f/32. The
rule of the use of a small aperture for securing crisp definition
and obtaining sharpness in different planes is well recognised by
the camera expert, and Dr. Rodman attributed a great deal of
his success in photomicrography to his observance of that rule.
Various methods of illumination for photographic purposes were
discussed, the Nernst lamp, when obtainable, being recommended.
As an example of the results obtained by the photogi'aphic and
the camera-lucida methods, the lantern view of a beautifully
finished pen-and-ink dra\\dng of Paramecium in conjugation, at a
magnification of x 300, was thrown on the screen. In this the
details of structure came out very finely, the cilia round the
bodies being perfectly distinct. The photographic record in
this case was unsatisfactory, details being absent. But it was
confessed that the camera-lucida drawing was not exactly the
true record as obtained with that instrument : it had been
improved afterwards and details added. The photomicrogi'aph
obtained from the same micro-slide from which the camera-
lucida drawing had been made was then projected for com-
parison, and showed by an absence of many of the characters
of the drawing that the latter had been produced at the cost
of a good deal of artistic licence, and was quite untruthful in
many points. In another example, however, the photomicro-

QUEKETT MICROSCOPICAL CLUB. 387

graph of Sertularia showed on the screen all details, and was,
of course, an exactly truthful representation, while the drawing
made with the camera lucida was very much less satisfactory in
many respects.

A series of lantern views of about 100 photomicrographs was
then thrown on the screen ; they were drawn from nearly all
classes of microscopic work — insects, pond life, botanical subjects,
marine objects, geology, histology, diatoms and foraminifera
being all copiously represented. The particular point which Dr.
Rodman desired to emphasise — viz. the possibility of obtaining
a very considerable depth of focus, giving a marked stereoscopic
effect — was distinctly evident in many examples in all classes.
Some diatom slides exhibited this feature excellently, and formed
most beautiful objects, with depth, and yet great sharpness of
detail. A slide of Heliopelta, and several strewn slides of perfect
specimens, may be particularly noticed. Foraminifera, of course,
illustrated this special feature extremely well, as did many
botanical objects, some slides of pollen being noticeable amongst
them. Especially effective were photographs of various plant
hairs, the stinging-hairs of the nettle, and hairs on leaves of Rosa
rugosa, Onosma alba, Pelargonium and Sage, among others, stand-
ing out with stereoscopic distinctness.

At the conclusion of the exhibition the President said Dr.
Rodman had put his arguments in favour of photography before
the meeting very effectively. His own view was that either
method was a means of collecting facts, and it was evident that
it would have taken anyone a very long time to depict the objects
by means of the camera lucida. At the same time, the camera
lucida is a valuable instrument. In fossil botany, for instance,
the student very often has to work with very imperfect material,
but by using a camera lucida he gets the proportions correct, and
constructs his drawing by combining facts which have been
brought before him by various specimens. He suggested a vote
of thanks to Dr. Rodman for his interesting communication, which
was heartily given by acclamation.

A paper by Mr. C. F. Rousselet, F.R.M.S., " Further Notes on
Collecting and Mounting Rotifera," and one by Mr. W. M. Bale,
" On Measuring the Magnifying Power of the Microscope, a
Simple Method," were, owing to shortness of time, read in title
only.

388 PROCEEDINGS OF THE

At the 528tli Ordinary Meeting of the Club, held on Novem-
ber 13th, 1917, the President, Dr. A. B. Rendle, M.A., F.R.S.,
F.L.S., in the chair, the minutes of the meeting held on
October 23rd were read and confirmed.

Messrs. Arthur R. Trist, Geo. H. Rodman, Gustasp Andaseer,
R. Guthrie Woodward, Stuart Lawson and Wilfrid J. Birch were
balloted for and duly elected members of the Club. Proposal
forms for two candidates were read for the first time.

The President announced that Mr. Ingpen, Honorary Secretary
from 1873 to 1883, had very kindly presented his microscope to
the Club. It was exhibited on the table, and included a valuable
set of accessories ; in addition to the instrument itself — a mono-
cular, with very complete mechanical substage — there were three
condensers, a full set of five eye-pieces, an extra draw-tube, a
camera lucida, a polariscope, and an Abbe apertometer, w4th
some other apparatus. In a letter to the President accompanying
the gift Mr. Ingpen explained that the instrument was a testi-
monial given to him by the Quekett Club on his relinquishing the
secretaryship ; it had been constantly used, and was greatly
valued by him. Now, however, owing to advancing age and the
failure of his eyesight, he was unable to continue his work, and
thought that he could not do better than return it to the present
representatives of the donors for their use, with his best wishes
for the continued prosperity of the Club. It was unanimously
resolved that the thanks of the members should be expressed
to Mr. Ingpen for his gift, coupled with their sympathy with him
in his sad affliction.

Dr. Rendle announced the death at an advanced age of
Dr. Robert Braithwaite, F.L.S., F.R.M.S. He joined the Club in
1865, was President in 1872-3, and had been an honorary member
since 1893. He was the author of a valuable series of papers on
the Sphagnaceae, and his British Moss Flora was well known.
He was President of the Royal Microscopical Society in 1891-2.

Dr. J. Rudd Leeson, F.L.S.,* F.R.M.S., then gave an
address on " The Life- History of the Gnat (Culex)," which was
illustrated by micro-preparations exhibited under microscopes
on the table. The Culicidae were characterised by their hair-
whorled antennae, the proboscis, and scales on the wings. All
so-called mosquitoes belonged to this order. There were about
a dozen species known in Great Britain. The larvae were

QUEKETT MICROSCOPICAL CLUB. 389

aquatic, and in order to understand their life-history the surface
tension of water should be studied, as it was essential to the
life of the gnat, which in all its phases was an air breather. The
eggs were laid in the form of a floating raft, about a quarter of
an inch in length, containing some 250 ; they were cigar-shaped,
pointed above and with a lid below, from which the larvae emerged.
The larva was heavier than water, yet required to breathe the
air; for this purpose a posterior breathing-tube, known as the
respiratory siphon, arose from the eighth abdominal segment,
and at the end was armed with five cusps, which, when expanded,
supported the creature tail upwards, by virtue of the surface
tension ; its head meanwhile sinking in the water, from which its
food was obtained. When alarmed it withdrew the cusps and
was able to progress by using the swimmerets at the end of the
body. After three or four months it pupated and the pupa did
not feed, but it was requisite that the head should be towards the
surface for the emergence of the perfect insect. To accomplish
this, two trumpet-shaped breathing-tubes were developed from
the back of the head, and these, owing to the surface tension, were
able to support the creature in the new position. Finally, the
pupa-case split along the back, and the gnat, withdrawing from it,
began its new life in the air. In reply to questions. Dr. Leeson said
the blood-sucking function was not well understood. Swarms
of gnats inhabited the Arctic regions where no animals existed
from which a supply could be drawn, so that the propensity could
hardly be considered essential to its existence. As the males did
not suck blood, it might, perhaps, be an accompaniment of the
reproductive function. The danger of contracting malaria from
the bite depended on the presence of infected people in the area
from whom the parasite might be transferred. Mr. N. E. Brown
referred to the dissemination of ague by Culex 'pipiens, and Mr.
Grundy remarked that ague in India was almost certain to follow
the bites of various gnats. After some observations by the chair-
man, a hearty vote of thanks was accorded to Dr. Leeson for his
communication.

Mr. Jas. Grundy, F.R.M.S., explained the polarising apparatus
given with the microscope by Mr. Ingpen. The theory of polarised
light, and the differences between plane, elliptical and circular
polarisation, were referred to. It was shown how rays of light
passing through the polariser were divided up into ordinary and

390 PROCEEDINGS OF THE

extraordinary rays, and from the relation between the refractive
index of calcite and that of the extraordinary ray this ray went
nearly straight through the polariser, and emerged as a plane
polarised beam of light, whose vibrations were parallel with the
short axis of the Nicol's prism, this being the principal way of
obtaining plane polarised light. Also the ordinary ray for a
similar reason could not pass through the polariser beyond the
dividing plane cemented with Canada balsam, but was refracted
at the surface of the balsam and lost. The analyser, which is
a prism similar to the polariser, treated rays of light in the same
way, and there the emergent rays vibrate again parallel to the
short axis of the Nicol ; only doubly refracting material is effective
for observation with polarised light, because unless it is doubly
refractive interference cannot be obtained, and therefore no
colour due to polarisation occurs. The President said it was
fortunate that Mr. Ingpen's gift had formed a subject for an
address on polarised light, and he suggested a hearty vote of thanks
to Mr. Grundy for his explanation ; this was given unanimously.

At the 529th Ordinary Meeting of the Club, held on Decem-
ber nth, 1917, Vice-President D. J. Scourfield, F.Z.S., F.R.M.S.,
in the chair, the minutes of the meeting held on November 13th
were read and confirmed.

Messrs. Edward Hight and Evan V. Pike were balloted for and
duly elected members of the Club. Nomination forms for two
candidates were read for the first time.

The chairman announced that Mr. C. F. Rousselet had presented
to the club several portraits, and also a further collection of photo-
graphs of drawings of Rotifera to be added to those he had already
given. He said that Mr.Rousselet's health was slightly improved,
and expressed the hope that it might in time be sufficiently
restored to enable him again to attend the meetings of the Club.
Mr. Bryce drew the attention of workers on the Rotifera to the
very valuable collection of drawings that Mr. Rousselet had
placed at their disposal. He said that there were among them
figures of many forms not described in Hudson and Gosse's work,
and urged the members to make use of them.

The Hon. h'ecretary announced that there would be no meeting
on December 25th, and that at the meeting on January 8th

QUEKETT MICROSCOPICAL CLUB. 391

nominations would be received to fill the vacancies on the com-
mittee caused by the retirement of the four senior members.

Mr. J. Milton Ofiord, F.R.M.S., then gave a lantern demonstra-
tion on Insects' Eggs. Mr. Offord apologised for giving an address
to the Club which contained nothing new, but he thought that the
beauty of the eggs was sufficient excuse for his bringing the subject
before the members. He drew attention to the remarkable
instinct which guides the insects in selecting a suitable place to
deposit their eggs, so that the young larva on emerging finds
suitable food close at hand. The emergence from the egg is>
sometimes a matter of considerable difficulty owing to the young
larva becoming entangled in the membrane with which the egg;
is lined. Some insects, earwigs for instance, sit on their eggs, but
the speaker was not able to explain why this is done. The eggs
of Lepidoptera are generally glued to the leaves of the food plant,
those of saw-ffies are laid in cuts or cre^dces of the bark, while
the eggs of the bot-fly are laid on the hair of horses so that they
may be transferred to the animals' mouths when they lick them-
selves, and so reach their stomachs where the development i&
continued.

A series of lantern, slides of eggs of various lepidoptera, diptera
and avian parasites was then shown on the screen, and although,
the beautiful iridescence was in some cases lost, the variety of
form was well exhibited. The photographs were taken with,
either a Zeiss Planar or a Zeiss 35-mm. projection lens. . The
first of the series were the eggs of butterffies, and a great variety^
of shape and markings was shown. The Cabbage White and the-
Brimstone lay long eggs rather pointed at one end ; they are
longitudinally ribbed, and the ribs are connected by crossbars-
which in the Brimstone's egg are dotted. The eggs of the
Chequered Skipper bear similar markings, but are shaped like an
orange. Mr. Offord suggested that this ribbing might be for the
sake of economy of material, to get as much strength as possible
with the amount of material used. The next egg shown, that oi
the Silver-studded Blue, was quite different ; its surface was.
covered with small tubercles, and its appearance greatly resembled
that of the seed of Silene. The eggs of the small Copper again
showed a shell apparently strengthened by projecting ridges^
but in this case the surface was honeycombed. Mr. Offord
then showed some moths' eggs : those of the Swallow-tail were

■"392 PROCEEDINGS OF THE

'tub -shaped, while those of the Canary-shouldered Thorn had been
'Compared by some of the men at the Y.M.C.A. huts to petrol-
tins, which they very much resemble in shape — both these eggs
are brilliantly iridescent. The speaker thought that the egg of
the Waved Umber was one of the, most beautiful : its surface is
honeycombed, and at the corner of each hexagon there is an
iridescent pearly boss. The next photograph was of the egg of
a fly, Anthomia. These eggs, which are ivory-white, are covered
with a fine network of hexagonal markings, and Mr. OfEord said
that under a high power secondary dottings could be seen similar
to those occurring in some of the Diatomaceae — e.g., Triceratium
favus. The remaining slides were of the curious eggs of bird-
parasites. The parasite of the Hornbill lays an egg of an ivory
colour with a little cap at one end of it ; this egg difiers in form
according to the position on the feather in which it is laid. The
last three slides showed eggs that resembled flowers, that of the
parasite of the Japanese turkey being singularly like a chrysan-
themum. The chairman proposed a hearty vote of thanks to
the speaker, and asked him what form of illumination was used
in taking the photographs. Mr. Ofiord replied that he found a
lieberkuhn the best, as it gave a strong light, although better
relief was given by using the silvered side-reflector ; he used an
inverted gas-mantle with the air-pressure carefully adjusted as
the source of light. Mr. Bryce said that he was surprised
Mr. Offord had kept the photographs so long before showing them
to the Club, and Mr. N. E. Brown drew attention to the use of the
concave substage-mirror to focus the light on opaque objects, a
method of illumination which gave very satisfactory results.

Mr. J. Grundy, F.R.M.S., then continued the address on
polarised light which he had started at the previous meeting.
He explained how it was that the best results in polarisation were
obtained by arranging the object-crystal with its axes at an angle
•of 45° to those of the crossed Nicols. He then dealt with circular
polarisation, and exhibited a portable table-polariscope, and ex-
plained how he used it. He also described various simple experi-
ments with the microscope, and demonstrated the passage of
•a ray of light through one and through two crystals of cakite.
Mr. Grundy explained that frequently the light reflected from the
sky and from all sorts of objects was polarised, and he exhibited
two pieces of apparatus which he used to detect this condition,

QUEKETT MICROSCOPICAL CLUB. 393

which was most frequent after rain at any time of the year.
After a hearty vote of thanks had been passed to Mr. Grundy, he
explained and demonstrated the use of the various pieces of
apparatus he had with him to those interested in the subject.

At the 530th Ordinary Meeting of the Club, held on January 8th,
1918, the President, Dr., A. B. Rendle, M.A., F.K.S., F.L.S., in
the chair, the minutes of the meeting held on December 11th
were read and confirmed.

Messrs. Francis Martin Duncan and Stanley Hirst were balloted
for and duly elected members of the Club. Three proposal forms
were read for the first time.

The President then read the names of those nominated by the
committee as officers for the ensuing year. The election of
officers and four members of committee will take place at the
annual general meeting on February 12th.

Dr. Eendle then spoke with regard to the proposal to use the
British Museum and also the Natural History branch at South
Kensington as Government offices. He said that the Govern-
ment Committee on Accommodation has been considering this
question for some time, and that apparently the British Museum
will be used by the Air Board. The fate of the Natural History
Museum, however, is not yet decided. The collections housed in
this building are of great educational value and the public take
a lively interest in them. Apart from the useful work done in the
exhibited series, there is the priceless collection forming the study
or working collection. This collection has been made at great
cost and is the result of at least 200 years' labour. Some of the
most valuable and fragile things are being put into safe places,
but great care is necessary in moving them and in choosing
suitable positions. What will happen if the Office of Works
undertakes this work ? Many of the collections, moreover, require
constant care. It is the duty of the curators to look after them
and protect them from the ravages of insects and fungi, and to
separate curators from collections is an unthinkable project.
The more pressure that is brought to bear on the Government
before they make their decision the better. Dr. Rendle then
moved the following resolution :

" The Council and members of the Quekett Microscopical Club

394: PROCEEDINGS OF THE

hear with consternation and regret of the proposal to utilise a
portion of the Natural History branch of the British Museum for
Government offices. Such a proposal is in their opinion opposed
to the best interests of the nation as threatening serious damage
to priceless and irreplaceable scientific specimens, and tending
greatly to embarrass the scientific work for the country both now
and in the future."

Mr. F. J. Perks, in seconding the resolution, said that if space
was required other more suitable buildings might be used ; picture
galleries, for instance, where the floor space could be used without
disturbing the pictures on the walls. Mr. Perks considered that
if the Natural History Museum was used great damage would
be done to the collections unless they were treated very differently
from the furniture and papers at his office which the Government
had occupied.

Mr. R. Paulson, F.L.S., said that shutting up the Museum would
mean the shutting up of a great deal of valuable scientific work.
In peace time the Museum is a centre for the whole world. Even
at the present time work of great value to the community is being
done there in connection with the preservation of food, such as
biscuits and grain, and the investigation of timber diseases.
Quite recently, the Museum staff had suggested a remedy for a
fungus which had attacked and destroyed thousands of pounds'
worth of army tents in Malta.

The resolution was passed unanimously, and the Secretary was
directed to send copies to the Prime Minister and The Times.

Mr. J. Milton Ofiord, F.R.M.S., then gave an address on Mos-
quitoes and Malaria. The common house gnat [Culex pipicns),
he said, is a beautiful object for the microscope, and has a most
interesting life-history. The eggs are glued together in the form
of a raft and are kept in position during oviposition by the crossed
hind legs of the female. The raft is unsinkable, and always floatr>
the riglit way up. The eggs are pointed at the top and flat at
the bottom end from which the young larva escapes. The larva
is aquatic, but breathes air, and for this purpose it comes to the
surface of the water and thrusts its breathing- tube through the
surface film. This tube projects from the dorsal surface of the last
segment but one, and one or two large tracheae open at its distal
end. At the fourth moult the larva changes into a pupa which
breathes air in a similar way, but by means of two tubes emergirig

QUEKETT MICROSCOPICAL CLUB. 395

from the dorsal surface of the thorax. The perfect gnat emerges^
from the pupa case while it floats on the water. Culex carries
no disease in this country, neither does Stegomyisi, hut Anopheles
maculi'pennis , which is also found in Britain, is the notorious
carrier of malaria. Usually there are very few cases of malaria
here, but now there are thousands of troops suffering from this
disease, and it is very desirable that these men should be placed
in districts in which Anopheles is not found until they have
recovered. Mr, Offord then described the points of difference
between Culex and Anopheles. In the case of Anopheles the eggs
are not laid fastened together like a raft. The breathing-tube of
the larva is so short that the larva floats in a horizontal position
at the surface of the water when breathing, instead of hanging^
head downwards at an angle of 45 deg., like Culex. The imago
has no scales on the body, and the resting positions are very^
different, Culex resting with the head and tip of the abdomen
down and the thorax farthest from the surface it rests on, while-
Anopheles rests with the head and body almost in a line, the head
being down and the tip of the abdomen raised. Mr. Offord then
briefly sketched the life-history of the malaria parasite, showing
how the sporozoite is introduced into the human blood during
the biting of the mosquito, enters a blood corpuscle, and develops
into an amoebula, which grows into a rosette and divides into
merozoites. The corpuscle then disintegrates, and the free
merozoites invade fresh corpuscles. After several cycles mero-
zoites develop into male and female crescents, which undergo no
further change until they again enter the stomach of a mosquito,
when after further developments an ovum is produced, which
elongates and bores through to the outer wall of the stomach,
where it forms a cyst. Sporozoites are formed in the cyst, which
bursts and they escape, those which reach the salivary glands
passing into a human being and starting the cycle again. The
lecturer then described the slides and specimens, most of which
were very kindly lent by Mr. Lang of the Natural History Museum .
He also read some notes which Mr. Lang had written, describing
the specimens, and giving some interesting details of the life-history
of gnats. Mr. Offord recommended members to notify the Museum
of localities where they found specimens of Anopheles, so that they
might be avoided by men suffering from malaria.

Mr. James Burton gave an interesting account of the feeding.

396 PROCEEDINGS OF TflE

of an Anopheles larva that he had taken at Epping in July 1913,
and stated that he had found two others at Lyon House in August
of the same year. Mr. Hilton moved a vote of thanks to
Mr. Lang for his kindness in sending the specimens and writing
a description of them, which was passed with acclamation, and
after some further remarks by Dr. Rodman and Dr. Leeson a
hearty vote of thanks was accorded to Mr. Ofltord for his interesting
address. A paper by Mr. E. M. Nelson on " The Measurement of
the Magnifying Power of the Microscope " was taken as read.

At the 531st Ordinary Meeting of this Club, held on
February 12th, 1917, the President, Dr. A. B. Rendle, M.A.,
F.R.S., F.L.S., in the chair, the minutes of the meeting held on
January 8th were read and confirmed.

Messrs. A. Goodman, Benjamin J. Thomas and Arthur H.
Niblett were balloted for and duly elected members of the Club.
Nomination forms were read for the first time on behalf of four
candidates.

The President read the list of nominations for the officers
and four members of the committee for the ensuing year. There
was very little change, and the nominees were duly elected.

The Secretary read the 52nd annual report, and the Treasurer
the balance sheet. Both indicated that the Club's affairs are
in a satisfactory position.

Mr. W. R. Traviss exhibited a specimen of the very useful life-
slide described by Mr. Banham in the last number of The English
Mechanic, and also an adapter to enable fairly high-power
-objectives to be used with a Wenham binocular. The adapter
can only be used for such objectives as have the optical system
separable from the mount. The end-piece is unscrewed, and the
upper part is cut off and drilled out to carry the optical part, which
is put in from the top. Mr. Traviss said that a useful substitute
for the adapter could be made from the cork from a vinegar
bottle, or a strip of paper of suitable length wound round the
objective end, so that it might be pushed or screwed into the nose-
piece.

The President then delivered his annual address, taking as his
subject " The Use of Microscopic Characters in the Systematic
^tudy of the Higher Plants."

QUEKETT MICROSCOPICAL CLUB. 39T

The President's address was illustrated by lantern slides, most
of which were kindly lent by Dr. Rodman.

Mri D. J. Scourfield proposed a vote of thanks to Dr. Rendle
for his interesting address, and appreciatory remarks were also
made by Mr. N. E. Brown and Dr. Leeson.

The President announced the nomination by the committee of
Mr. Thos. H. Powell as an honorary member. Mr. Powell is one
of the oldest members of the Club, and the announcement was-
received with acclamation.

The next Ordinary Meeting will be held on March 12th, when
there will be a short paper by Mr. C. D. Soar, F.L.S., F.R.M.S.^
on a Water-mite, Lebertia sefvei, and a paper by Mr. G. T. Harris
on the moss Schistostega osmundacea.

The result of the ballot for the election of officers for the ensuing,
year was :

For President . A. B. Rendle, D.Sc, F.R.S., F.L.S.

I Prof. Arthur Dendy, D.Sc, F.R.S., F.L.S.
C. F. Rousselet, F.R.M.S.
D. J. Scourfield, F.Z.S., F.R.M.S.
David Bryce.
For Treasurer . Frederick J. Perks.
For Secretary . James Burton.

For Foreign Secretary C. F. Rousselet, F.R.M.S.
,, Librarian . Alfred George.
,, Curator . . C. J. Sid well, F.R.M.S.
,, Editor . . A. W. Sheppard, F.R.M.S.

Four members to fill vacancies on Committee :

Mr. N. E. Brown, A.L.S.

Mr. Chas. D. Soar, F.L.S., F.R.M.S.

Mr. C. H. Bestow, F.R.M.S.

Mr. A. Morley Jones.

At the 532nd Ordinary Meeting of the Club, held on March 12thy
Vice-President D. J. Scourfield, F.Z.S., F.R.M.S., in the chair^
the minutes of the meeting held on February 12th were read and
confirmed.

Messrs. E. Doddrell Evens, Basil A. Adams, W. J. Robertson
and Edward J. Burrell were balloted for and duly elected members-

^98 PROCEEDINGS OP THE QUEKETT MICROSCOPICAL CLUB.

-of the Club. Nomination forms on behalf of three candidates were
read for the first time.

The chairman then called upon the Secretary to read Mr. G. T.
Harris's paper on Schistostega osmundacea Mohr.

After some remarks by Messrs. Scourfield, Grundy, Hinton
and Burton, a hearty vote of thanks was accorded to Mr. Harris
for his interesting paper. Mr. Scourfield exhibited a specimen of
Schistostega in which the luminous appearance was very beauti-
fully shown by means of a vertical illuminator.

Mr. F. J. Perks then read a paper by Messrs. Williamson and
Soar on Lebertia sefvei Walter. This water- mite is of interest on
account of the fact that the species was previously recorded as
having been found only in Swedish Lapland. The discovery of
the Arctic form in Dartmoor brings the number of the Britannic
species of this genus up to twelve. A single specimen of which
the sex cannot be determined was taken by Mr. D. J. Scourfield
at Fernworthy Bog, Dartmoor, in August 1917.

At the meeting of the Club on April 9th Sir Nicholas
Yermaloff, K.C.B., will read a paper, illustrated by lantern slides,
entitled " Notes on Some Intermediate Forms of the Genera
Cymbella and Navicula."

399

FIFTY-SECOND ANNUAL REPORT.

In presenting the Keport for the year ending December 1917,
your Committee feel that though there is some ground for review-
ing the work and condition of the Club with less satisfaction than
usual, yet taking into consideration the many difficulties caused
by the long continuance of the war, the retrospect may be regarded
with equanimity, and the future anticipated without anxiety.
During the year thirty-four new members were elected, fifteen
have resigned, and eight have been lost by death. The present
total number is 438. Mr. Alpheus Smith, who was for forty
years the Hon. Librarian, and on his retirement, rendered neces-
sary by age and infirmities, was elected an honorary member,
died in May, at the age of eighty-seven. Dr. Robert Braithwaite,
a past President, and who had been an honorary member since
1893, died in October in his ninety-fourth year. Obituary
notices of these two members of the Club will be found in the
Journal. The death of Mr. Geo. Massee, formerly President, but
not a member in recent years, was announced in June. Sir W. H.
Lindley, who joined the Club in 1868, and was thus quite one of
the older members, but had lived in Germany for many years,
has also been removed by death. The Hon. Francis Walter
McLaren, M.P., J.P., met his death in August in a flying accident
in Scotland.

The attendance at both the Ordinary and Gossip Meetings has
somewhat fallen off, which is amply accounted for, not only by
the much-restricted service of conveyances and the darkness of
the streets, but by the possibility of air raids, as when these occur
the almost total stoppage of traffic makes it extremely incon-
venient for those living in the suburbs. These difficulties of
course particularly affect those of our members who are no longer
young, and thus we lose the advantage and pleasure of their
presence, which would not happen under more normal conditions.
We tnuch regret the continued absence of Mr. C. F. Rousselet

400 FIFTY-SECOND ANNUAL REPORT.

through his serious illness, and are glad to hear at present of some
slight improvement in his health. Mr. S. C. Akehurst, who has
been Hon. Librarian since 1912, found it necessary in June to
resign, owing to his acceptance of an official position in the special
constabulary. Mr. Todd, till then Assistant Librarian, consented
to take up the responsibilities, and Mr. A. E. Bull was appointed
assistant. It was hoped that it would be found possible to supply
books from the Library to members living in the country in an
efficient way, but almost immediately afterwards Mr. Bull was
requisitioned by the military, and had to leave at very short
notice. Mr. Alfred George then kindly offered to undertake to
carry on the work of Librarian, at least till the end of the
year, with Mr. Todd as second. Mr. C. J. Sidwell, who has
performed the very exacting duties of Curator most efficiently
and unselfishly for many years, found that owing to the unsatis-
factory state of his health he was unable to go on with the extra
work attending the preparation and issue of a new catalogue of
the large number of micro-slides in the Cabinet. It was decided
that Mr. Sidwell should be commissioned to obtain any help he
found necessary, and that the Club should be responsible for
expenses incurred thereby. Mr. Sidwell assented to this arrange-
ment and kindly withdrew his resignation. The almost complete
absence of exhibits of new apparatus by the various opticians
will be noticed, caused, as in the two previous years, by the fact
that their output and energies are entirely taken up with Govern-
ment work.

It was noticed when the new session began in October that all
through the season the Fourth Tuesday in each month — the night
of the Ordinary meetings — coincided with the full moon, or within
a very few days of it ; and as it was believed that air raids were
more likely to take place at these times, the Committee decided
to change the date of the ordinary meetings to the second Tuesday,
putting the Gossip night on the fourth instead.

A number of the members of the Club have throughout the
year — as in the previous year — exhibited microscopic specimens
to very numerous audiences of soldiers at the hospitals and
Y.M.C.A. huts ; these efforts for their entertainment have always
been highly appreciated.

The principal communications at the meetings during the year
are as follows :

fifty-second annual report. 40l

Papers read and Communications made to the Q.M.C. to

THE End of the Year 1917.

January 23r(Z. — Mr. David Bryce : On the Collection of the
Bdelloid Rotifers. Exhibition of apparatus.

February 21th. — Presidential Address, Prof. Arthur Dendy :
The Chessman Spicule of the Genus Latrunculia : a Study in
the Origin of Specific Characters.

March 21th. — Mr. A. E. Hilton : On Trichia affinis, one of the
Mycetozoa. Mr. C. D. Soar : Two New Species of Freshwater
Mites. Mr. G. T. Harris : The Desmid Flora of Dartmoor.

April 2Ath. — Dr. J. Rudd Leeson : On the Common House-Fly,
with Especial Reference to its Danger to Health.

May 22nd. — Dr. Alfred B. Rendle : On Colour in Plants and its
Preservation. Exhibition of Plants : Specimens for Museums
and Herbariums.

June 2M. — Mr. N. E. Brown : Evolution as illustrated by a
Genus of Plants. Exhibition of Living Plants.

October 23rd. — Dr. G. H. Rodman : Lantern Demonstration of
Photomicrographs, with description and explanation.

November 13th. — Mr. Jas. Grundy : On Polarisation.

December Wth. — Mr. OfEord, F.R.M.S., Lantern Demonstration
of Insects' Eggs, with description. Mr. Jas. Grundy:
Further Remarks on Polarisation, with Exhibition of appara-
tus illustrative of the various methods.

The Committee desires to thank those who have done so much
by their papers and addresses to interest the Club. The delay
in the appearance of the Journal is the inevitable result of the
shortness of labour in the printing trade owing to the war.

The Hon. Secretary of the Excursion Sub-Committee reports
that the excursions were very satisfactory. Nine were arranged
for, and the average attendance was 20'9, a higher figure than in
the two previous years. Although nothing unusual in the way
of finds was recorded, much interesting material was obtained,
and the junior members benefited by the experience of those
more expert in the practice of pond-hunting. The visit to the
Royal Botanic Gardens, Regent's Park, in April showed how
greatly this excursion is appreciated, forty- two members being
present, and the thanks of the Club are due to the Royal Botanical
Society for their kindness in admitting the visitors. Thanks are

JouRN. Q. M. C, Series II.— No. 82 30

402 FIFTY-SECOXD ANNUAL REPORf.

also due to Sir Philip Sassoon for the privilege of collecting in
the ponds in Trent Park.

On the occasion of the excursion to Hampton Court the members
were entertained to tea by Dr. and Mrs. Leeson ; at the Greenford
and Ealing excursion Mr. and Mrs. OfEord showed their hospitality
for the third time ; and Mr. and Mrs. Wilson performed the same
kind action on the occasion of the Richmond Park outing. Dr.
Measures undertook the expense for the requisite meal at
Waltham Abbey ; and Mr. Tilling performed the same kind
ofhce at Higham's Park. All these friends and members of the
Club have earned the gratitude of the excursionists for these very
welcome services.

The list of books and pamphlets, etc., added to the Library
since the end of April of last year was as follows :

List of Books, Journals, Reports, etc., received

DURING the Year.

Boohs.

Plant Teratology. Vol. IL Ray Society.

Purchased.
Quain's Anatomy. Vols. I and IL

Presented hy Dr. G. Burton Brown.
Histology of Medicinal Plants.

Mansfield. Presented hy the Publishers.
Guide to the Exhibited Series of Insects.

Dept. of Zoology, Brit. Museum (Nat. Hist.) Presented,
Recherches sur les Rotiferes.

Beauchamp. Purchased.

Journals, Reports, etc.

American Microscojncal Society. Vol. XXXV., Nos. 3, 4 —

Vol. XXXVI.,Nos. 1,2.
Academy Natural Sciences. Philadelphia. Vol. LXIX., Part ].
British Association, Report of. Newcastle, 1916.
Brighton and Hove Natural History Society, An7iual Report,

' June 1916, July 1917.
Bristol Naturalists^ Society, Annual Reports and Proceedings.
1912-13-14-15.

PIFTY-SECOND ANNUAL REPORT. 403

Bergens Museum Aarboh. 19U-15. Pt. 3—1915-16, Pts. 1, 2.

Bergens Museum Aarsheretning . 1914-15 — 1915-16.

Croydon Natural History Society. Vol. VIIL, Pt. 3.

Edinburgh, Botanical Society of. Vol. XXVII., Pt. 1.

Glasgow Naturalist. Vol. VIII., Nos. 1, 2.

Geologists' Association. Vol. XXVIII., Pts. 1, 2, 3.

Hastings and East Sussex Naturalist. Vol. II., No. 6.

Hertfordshire Natural History Society. Vol. XVL, Pts. 3, 4.

Illinois Biolog. Monographs. Vol. II., No. 4.

Missouri Botanical Gardens, Annals of. Vol. III., Nos. 2, 3, 4 —

Vol. IV. Nos. 1, 2.
Manchester Literary and Philosophical Society. Vol. LXI., Pt. 1 .
Manchester Microscopical Society, Annual Report. 1916.
Photomicrographic Society. Vol. V., No. 3. Vol. VI., Nos. 1. 2.
Philippine Journal of Science :

Section A. Vol. XL, Nos. 4, 5, 6.
„ XIL, Nos. 1, 2.

B. Vol. XI., Nos. 5, 6.
XII.,Nos. 1,2, 3, 4, 5.

C. Vol. XI., Nos. 4, 5, 6.
XIL, Nos. 1, 2, 3, 4, 5.

D. Vol. XII. Nos. 1, 2, 3.

)5

3 J

Quarterly Journal Microscopical Science. Vol. LXIL, Pts. 2, 3.

Q. M. C. Journal Vol. XIIL, Nos. 78, 79.

Royal Society. Vol. LXXXIX. B. 618, 620, 621, 622, 623,

624, 625.
Royal Society New South Wales. Vol. L., Pts. 2, 3.
Rojjal Microscopical Society Journal, 1917. Pts. 1, 2, 3, 4, 5, 6.
Rotjal Dublin Society, Proceedings, Vol. XV., Nos. 15, 16, 17, 18,

19, 20, 21, 22, 23. Economics. Vol. IL, Nos. 12, 13.
Redia. Vol. XIL, Pts. 1, 2.

Torquay Natural History Society. Vol. IL, No. 3.
U.S. National Museum. Bulletins. Nos. 71, Pt. 6—93, 95, 96,

98-100. Vol. L, Pt. 1, 101, 102, Pts. 1, 2, 3.
U.S. National Herbarium. Vol. XVIIL, Pts. 5, 6, 7. Vol. XX .,

Pts. 1, 2.
Victorian Naturalist. Vol. XXXIIL, Nos. 8, 9, 10, 11, 12—

Vol. XXXIV., Nos. 3, 4, 5
Wisconsin Academy. Vol. XVIIL, Pt. 2,

404 FIFTY-SECOND ANNUAL REPORT.

The Hon. Curator reports that the number of slides lent to
members has been quite up to the average. Slides to the number
of 155 have been added to the Cabinets by Mr. C. F. Kousselet,
who has again increased the Club's indebtedness to him by
placing at its disposal his miscellaneous preparations. During
the year the Club has been presented with a complete Zeiss micro-
scope and apparatus from Mr. Ingpen. This was originally pre-
sented to him as a testimonial by the Club some thirty years ago.

Amongst the apparatus is an Abbe apertometer, which should
prove useful to any member desirous of measuring the numerical
aperture of his objectives. The collection of slides is undergoing
thorough revision, and a manuscript catalogue is in course of
preparation, with the view to its being printed after the war.
The thanks of the Committee are due to Messrs. Bestow & Gardner
for assistance rendered to the Curator in the issue of slides, and
also to Mr. J. M. Offord for kindly officiating with the lantern.

Mr. L. C. Bennett has continued the valuable help he has given
the Club for several years, in making welcome visitors and nevrly
elected members at the meetings, and the Committee tender him
their thanks for this very useful service.

The Committee feel sure that members will join with them in
thanking the officers for their zeal in carrying on the necessary
work of the Club, under circumstances which make it particularly
trying and arduous, and they desire to call upon all to second these
efforts with the object of securing the continued success and
prosperity of the Quekett Microscopical Club.

405

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00

o

o

02 -^

13 s:^

40 4^

o o

;-i P4 P4
O O O

Qj f-t r-i
•^4^40

?M ^ ^

4-3

o
Ph

iHIiM

(M

OQ

O
-ill
4i

-d

;^

a,

B
o
o

pi

O)
=!

• ^-(

■73

c3

00
4i

JJ

o

o
o

(D

4-3

<U

40 O

> <p

o ^

^ o

a>

00
00

i 12

" a. .9

4-3

M
a

00

<D frj CD

"Si

o

02
1^

o

H

1-5 pq

00

5;^

02

Q

406

Table fob the Conversion of Encjlish and Metrical
Linear Measures; Yard and Metre at same Temperature.

1-^

mm.

1-H

/*

1 -r-

M

1 -r-

fi

l-^

/^

2

12-70

27

940

53

479

79

321

125

203

3

8-46

28

907

54

470

80

317

130

195

4

G-35

29

876

55

462

81

313

135

188

0

5-08

30

846

56

453

82

310

140

181

6

4-23

31

819

57

445

83

306

145

175

7

3-63

32

794

58

438

84

302

150

169

8

3-17

33

769

59

430

85

299

155

164

9

2-82

34

747

60

423

86

295

160

159

10

2-54

35

725

61

416

87

292

165

154

11

2-31

36

705

62

410

88

289

170

149

12

212

37

686

63

403

89

285

175

145

13

1-95

38

668

64

397

90

282

180

141

14

isl

39

651

65

391

91

279

185

137

15

1-G9

40

635

66

385

92

276

190

134

16

1-59

41

619

67

379

93

273

195

130

17

1-49

42

605

68

373

94

270

200

127

18

1-41

43

591

69

368

95

267

205

124

19

1-34

44

577

70

363

96

265

210

121

20

1-27

45

564

71

358

97

262

215

118

21

1-21

46

552

72

353

98

259

220

115

22

115

47

540

73

348

99

256

225

113

23

MO

48

529

74

343

100

254

230

110

24

1-06

49

518

75

339

105

242

235

108

25

102

50

508

76

334

110

231

240

106

A*

51

498

77

330

115

221

245

104

26

977

52

488

78

326

120

212

250

102

As the measuremeuts of many microscopical objects are given in
fractions of an inch in English literature, and in metrical measure in
foreign works, the above table has been drawn up to facilitate com-
parison. Its use is obvious. Examples : l/7th inch = 3-63 mm., l/58thinch
= 438 /i, or '438 mm. For fractions smaller than l/250th inch that portion
of the table between the figures 26 and 99 may be used by cutting off
the last figure for hundredths, and the two last figures for thousandths.
Examples : l/270th inch = 94-0 /*, or -0940 mm. ; l/79O0th inch = 321 /x,
or '00321 mm. When that portion of the table between the figures 100
and 250 is used it is only necessary to cut off the last figure for thousandths
and the two last figures for ten thousandths. Examples : 1/I350th inch
= 18-8 n, or -0188 mm., l/16500th inch = 1-54 /x, or -00154 mm. The
conversion of millimetres into fractions of an inch is performed in the same
manner ; r thus, 529 /x or -529 mm. = l/48th inch ; 39*7 fi or -0397 mm.
- 1/C40th inch; 2*62 /i or 00262 mm. = l/9700th inch ; 1-04 fi or -00104
mm. = 1/2 1500th inch; -977 ^ or '000977 mm. - l/26000th inch, and
BO on. — E. M. N.

407

MOTES ON SOME INTERMEDIATE FORMS OF THE
GENERA NAVICULA AND CYMBELLA.

By Sir Nicholas Yermoloff, K.C.B., K.C.V.O., F.R.M.S,

{Read April 9th, 1918.)
Plates 26-28.

All students of Diatoms are invariably impressed by the immense
number of individual forms, species, sub-species and varieties
patiently noted, described, named and classified. The differences
of diagnosis which have led to the creation of new forms are
undoubtedly sometimes very trifling and uncertain, based upon
personal impressions of observers, and, together with the enormous
multiplication of forms, there has arisen a veritable labyrinth of
confused synonymy.

From time to time, distinguished authors have tried to remedy
this state of things and to put some order in this chaos, striving
to reduce the existing number of admitted species and varieties,
and basing the regrouping they proposed, not so much on indi-
vidual variations as upon similarities of forms. Such regroupings
have been attempted by Cleve as regards the genus Navicula, by
Cox and Kattray as regards Coscinodiscus.

It cannot be admitted that these attempts have until now
proved very successful and fruitful. On the pages of one of
such recent reformers we read : " The reduction of the enormous
catalogues of species of Diatomaceae is a consummation devoutly
to be wished."

Well, perhaps I am mistaken, but I am not so sure that this
consummation is so devoutly to be wished as all that : it seems
to me that the admirably patient and careful labour of registering
minutiae, and the consequent subdivision of species, has been
both fruitful and inevitable. It has been — to borrow a term
from higher mathematics — a process of " differentiation," a study
and investigation of the elemental variations of the so-called

JouEN. Q. M. C, Series II.— No. 83. 31

408 SIR NICHOLAS YERMOLOFF ON SOME INTERMEDIATE FORMS

" variable." No reverse process of synthetic grouping, or, if I
may again use a term of mathematics, no process of " integration"
is possible and thinkable without the previous exhaustive exam-
ination of the elemental " differentials." It would therefore seem
to me that the consummation devoutly to be wished would lie in
another direction — not in the curtailing of the differentiating
operations, but in a process of reverse character, namely, in a
process of synthetic integration, undertaken after the study of
variations had been thoroughly mastered. This reverse process
ought to be performed, as is again done in mathematics, according
to some definite method and plan within certain limits.

One of your illustrious writers has truly said : "111 can he
rule the great that cannot reach the small." Nothing is more
true in a scientific sense : before undertaking any work of inte-
gration we must thoroughly master variation in all its forms.

To return to Diatoms, it is to be noted that the variations of
intermediate forms by no means appear as a rule to be abrupt ;
on the contrary, they are usually very gradual, and, I should say,
continuous, insensibly passing from one form into another. But
that peculiarity in Nature is most precious, and immediately
gives us guidance as to how to proceed farther : on the one hand
it leads us towards Darwin's doctrines of Evolution ; on the
other hand it brings the study of a biological subject closer to
the ideas of abstract mathematics.

The work of synthetic integration I am speaking about cannot
of course be done, so to say, accidentally or at random : it must
be done according to some guiding idea, and must follow some
definite formula or plan. At the present stage of diatom sys-
tematics it is perhaps feasible to make an attempt in that direc-
tion. Such an attempt, however small, forms the subject of this
paper.

In the course of my paper I shall have occasion to explain that
a certain fossil Diatom, found in the freshwater deposits of the
American State of Maine — Navicula Monmouthiana — may be con-
sidered as an ancestral form of a whole series of species of
Cymljella which I am about to describe. It would seem that this
ancestral form, through the course of many centuries, had passed
through a long series of many slight transformations, evolving
about fifteen forms of Cymbella extremely near and similar to
each other, and closing the series in a very small form, Cymbella

OF THE GENERA NAVICULA AND CYMBELLA. 409

microcephala, wliicli I will also describe. If we go down or up
this ladder we shall see how insensibly the intermediate forms
pass from one into another.

Now before I proceed along this ladder I should like to state
that the majority of freshwater Diatoms as a rule favour cold
climates, cold waters, cold mountainous streams. It has been
even ascertained that the higher the altitudes they are found in,
the more they thrive and the more pronounced and dense are
their markings. It would seem therefore natural to suppose
that the parental fossil form I am speaking about, Navicular
Monmouthiana, appeared on the scene in the State of Maine, at
the latitude of 45 degrees north, in other words at the latitude of
the Great Lakes of Canada, about the end of the Pliocene period,
just about the beginning of the Glacial epochs. At that time,
as is admitted by geologists, the continent which connected North
America with Europe — the so-called Atlantis — under the influence
of volcanic action began to break up, opening into more southern
seas a passage for the colder waters of the Polar regions, and
bringing down the great glacial deposits of ice as far south as
the Great Lakes. At that time the climatic conditions on our
earth began to undergo great and important changes : until then
the uniformly tropical climates prevailing much farther north
than the 45th parallel were beginning to cool and to give way to
colder conditions, heralding in the Glacial epochs. It was at the
end of the Pliocene that the large proboscidian mammals began
also to disappear from high latitudes, or at least that some of
them began, like the mammoths, to have fur coats. It was after
the end of the Glacial epochs, and with the advent on our planet
of temperate climates, that there began also the distribution of
the Angiosperm Flora, resulting in the differentiation of the many
groups of modern vegetation. It would therefore be natural to
suppose that about the end of the Glacial periods the parental
form, Navicula MonmoutJiiana, started upon its path of variations,
evolving the many descendant forms I am about to describe. If
we admit that this work of evolution started on its way after the
disappearance from the regions of the Great Canadian Lakes of
the last ice sheet of the Glacial epoch, we could reasonably assign
for it the whole of the Quarternary period up to the present day.
In the light of the comparison with higher mathematics with
which I began my paper, we may suppose Navicula Monmouth-

410 SIR NICHOLAS YEPv:\IOLOFF OX SOME IXTERMEDIATE FORMS

iana to be a sort of " integral" to begin with, and the Cymhella
microcephala the last "derived function" of the series. Indeed,
we may say that Nature herself is a great and patient mathema-
tician, one whose integrals are primordial forms and whose derived
functions are what naturalists call " species." And from this
point of view it would perhaps be permissible to introduce, I
should not say a new, but a different defiintion of v/hat in natural
history is meant by the word " species " : it is a definition which
was advocated in Russian scientific circles before the war :

" A species in Nature corresponds to what in the Differential
Calculus is meant by a ' derived function ' : it is a certain type-
limit, to which tend, without even sometimes quite identically
attaining it, certain varying intermediate forms."

The distinguishing features upon which are founded the sys-
tematic classification of Diatoms belong to seven categories :

(1) Habitat. — Whether freshwater, brackish water or marine^
This is a very constant and definite feature.

(2) Modus Vivendi. — Whether free, stipitate, enclosed in mucila-
ginous tubes, living individually, or in colonies, bands, chains
and the like. This is a very uncertain and changeable feature of
distinction.

(3) Size. — A fairly constant featm'e within certain limits.

(4) Exterior structure of the valves as to : raphe, nodules, costae
or striae, also as to hyaline axial and central zones. This is a
very important category, liable to many variations, yet usually
constant within certain limits.

(5) Interior structure and arrangements : septa, loculi, zone
details in the frustule view.

(6) Outline form of the valves, of the margins and ends. A
most important category of distinctive features.

(7) The distribution of the endochrome as regards chromatophores,
pyrenoids, etc.

All the above seven categories are important for the deter-
mination of forms, but not equally so. Some are more, some are
less, constant and reliable. To show how careful the observer
has to be even with such a comparatively constant distinctive
feature as habitat^ whether a diatom is freshwater, brackish water
or marine, I vvill state the case of the so-called Fragillaria rntarc-
tica. Now nearly all Fragillariae are freshwater. Vet Fragillaria

OF THE GENERA NAVICULA AND CiTMBELLA. 411

antarctica is found in enormous numbers in slides from the bottom
of the Antarctic Ocean at a deptli of 2,000 fathoms. How did
it get there ? The explanation was given by my late much-
lamented friend, Sir John Murray. It is this : Fragillaria antarc-
tica, a freshwater diatom,lives in huge quantities on the Antarctic
lands. It is carried away on floes of ice to the open sea, and
when the ice melts or breaks up it floats in the ocean as a pelagic
plankton, and when it dies, its skeleton falls down to the sea bed,
where it goes to form a Diatom Ooze, and where it was found in
abundance by the soundings of H.M.S. Challenger. As a general
rule, it is in structure, size and outline that the systematist has
chiefly to guide himself for the determination of species and
varieties. It is therefore also in structure, size and outline that
we have to seek for some guiding principle as to synthetic
integration.

The main line upon which it would be perhaps possible to look
out for synthetic grouping would seem to lie in a close study of
undoubtedly intermediate forms, and in an effort to detect affini-
ties between them, seeking a disclosure in these relationships of
what may be called " descendancy " or "lineage" evolved
through time and ages. Fossil and living forms are to be closely
compared and connected with one another. We must try to
guide our systematic studies by " genealogical descent."

In Volume I of the standard Synopsis of Naviculoicl Diatoms,
by Cleve (p. 157), is to be found a hint how to approach this
problem. There the author seeks to establish two lines of genea-
logical descent as regards several species of the genus Cymbella.
His hint seemed to me most promising and fruitful, and I have
tried to pursue it farther, taking up not the genus Cymbella as
a whole, but only some of its tribes. I have tried to establish
connecting links within certain limits, showing how intermediate
forms seem to pass one into another as regards structure, outline
and size.

In his book Professor Cleve traces relationships between species
of Cymbella along two genealogic lines, starting in one case from
Navicula dicepJiala, and in the other from a marine Navicula,
Navicula Bulnheimii. I have taken up his second line and tried
to trace a passage from and connection betvv^een about a dozen
species, sketches and microphotographs of which accompany this
paper. I do not, however, include in my series the Navicula

412 SIR NICHOLAS YERMOLOFF OX SOME INTERMEDIATE FORMS

Bulnheimii, which is a marine form, whereas all the forms of my
study are freshwater. I moreover begin my series with the form
which appears to be the ancestral parental one, Navicula Mon-
mouthiana.

The genealogical series which I am about to describe runs in
the following order. Here I should like to make the following
remark : it is hardly desirable that so-called intermediate forms
should receive special names ; it would seem better to give
them so-called "hyphenated" nominations, stating the initial
form from which they seem to start, and the final form to
which they appear to tend. Thus, a form intermediate between
Monmouthiana and Stodderi ought to be named thus: Mon-
moutJiiana-Stodderi.

The series runs as follows :

1. Navicula Monmouthiana Grun.

2. Navicula MonnioiUhiana Grun.

3. Navicula Monmouthiana- Stodderi.

4. Cymhclla Stodderi Cleve.

5. Cymhella Stodderi Cleve.

6. Cymhclla aequalis W. Sm.

7. Cymhella aequalis W. Sm.

8. Cymhella angustata W. Sm.

9. Encyonema gracilis Rabh.

10. Encyonema Scotica W. Sm.

11. Cymhclla delicatula Kiitz.

12. Cymhella gracilis-Cesatii.

13. Cymhclla Cesatii Rabh.

14. Cymhella microcephala Grun.

This series could be arranged under one heading which, for the
purpose of this paper,! would style the "Monmouthiana Integral "'
(Plate 26).

Although the series begins with Navicula Monmouthiana and
ends with Cymhella microcephala, yet I will, in order to follow
Cleve, describe the different species in the reverse sequence, be-
ginning with Cymhella microcephala. The sketches and micro-
photographs accompanying this paper have been taken. from four
slides, two from Europe (St. Fiore, Italy, and Premnay Peat,
Scotland) and two from North America (Herkimer in the State
of New York and Monmouth-Chcrryficld in the State of Maine).

OP THE GENERA NAVICULA AND CYMBELLA. 413

I may mention here that Herkimer is a small town on the River
Mohawk, a mountainous stream cutting its way through a spur
of the Adirondacks, just a place for Cymbellae to live in, it being
well known that Cymbellae as a rule much favour clear moun-
tainous streams in alpine regions. And in reality the Herkimer
slide is full of various Cymbellae.

The Monmouth-Cherryfield slides contain fossil forms ; both
these places are small towns in the State of Maine, not far from
the Atlantic coast on the line from Portland to Bangor, at about
43° N. This is interesting, as it seems that a relationship can be
traced between the Herkimer Cymbellae and the fossil forms of
the Maine deposits. Indeed, according to Cleve, some of the
Herkimer species, as for instance Cymhella Stodderi, are also to
be found in the White Mountains in the State of New Hampshire,
nearly at the same latitude between the Adirondacks and the
State of Maine. Before entering into specific details I would
mention that the Cymbellae described all belong to the " narrow "
or " naviculoid" type, very slightly asymmetric, and with both
margins convex. Some belong to the Encyonema group, living
in gelatinous tubes and with terminal nodules distant from the
ends — the chief characteristic of this group.

The generic characteristics of the genus Cymbella are too well
known to be repeated here. I would add only a few remarks :

(1) As far as I am able to observe, the central nodule, being
eccentric, may lie either on the ventral or on the dorsal side.

(2) The terminal fissures are comma-like, and are turned in the
same direction, opposed to the side on which lies the central
nodule.

(3) The raphe towards the ends seems to be always a little
arcuate or oblique, but towards the central nodule appears as if
it were slightly thickened, or as if it were approaching the upper
surface of the valve from below. Under low powers the oblique
part is usually invisible, but the thickened part is always seen.
This view is very characteristic of Cymbellae, even in the smallest
and least asymmetrical individuals. It is sometimes observable
even in those Naviculae which are intermediate to Cymbellae.

(4) Some of the forms which I am going to describe show on
the median striae a punctum or stigma, more or less distinct. This
stigma causes the median stria to appear as if it coalesced with
the central nodule. According to van Heurck, this peculiarity

414 SIR NICHOLAS YERMOLOFF ON SOME INTERMEDIATE FORMS

is well known and recorded as regards Encyonema Scotica and
perhaps Encyonema gracilis, but it does not seem to have b^en
noted as regards Cymbella Cesatii. Yet there it is. There is
therefore reason to admit that those forms which possess the
stigma are iutcr-nediate between Encyonema gracilis and
Cymhella Cesatii. Not wishing to multiply names, I have, for
convenience' sake, noted such forms with the stigma as
Encyonema gracilis-Cesatii.

(5) The forms which I have sketched and photographed as
Cymhella {Encyonema) gracilis-Cesatii in the Herkimer slide may-
be a new species. I have nowhere found a correct description of
them. Apart from the peculiar stigma they show other peculiar
features : their outline is more or less rhomboidal, and on some
indi\iduals very cymbelloid, or rather bent along the longitudinal
axis. The terminal nodules are always distant. They are very
narrow. The stigma gives them a false appearance of Gom-
phonema, yet the striae are so radiate that they have not the
facies of a Gom/phonema.

(6) Some of the forms I am about to describe have a decided
tendency to triundulate margins, or at least one of the margins
shows triundulation. Whether it is a specific characteristic or
an intermediate one I cannot say, but anyhow Cymbella angustata
is stated by Cleve to be slightly triundulate, and so it is. But
slight triundulation is noticeable also in Cymhella Cesatii, the
forms sketched as Encyonema gracilis-Cesatii, and also in the
robust Encyonema gracilis of the Monmouth-Cherry field deposits.
These, however, have nowhere been recorded in existing descrip-
tions as regularly triundulate. I am inclined, therefore, to con-
sider such triundulation as a sort of transitional characteristic,
appearing on intermediate forms. I wonder whether as a rule
there may not be characteristics which ought not to be described
as "specific," but rather, and only, as "transitional," i.e. as
belonging only to intermediate forms.

(7) As regards hyaline areas (axial and central) these as a rule
are more developed on American than on European specimens.

(8) The majority of forms in the Monmouth-Cherryfield slides,
which look very much like Navicula Mi>:imouthiana, nevertheless
do Tiot appear to be quite identical with the type form of
Navicula Monmouthiana. I will point out the difference at the

on elusion of my paper.

of the genera navicula and cymbella. 415

The Genealogical Ladder

Cynibella microcephala (Plate 28, figs. 18, 19).

This small Cymbella is common in European deposits. The
striae are very faint and dense (25 to 0*01 mm.), parallel. The
ends are rostrate-capitate. The areas indistinct. The outline
slightly asymmetrical. Length about 0 '03 mm. The typical form
is a little smaller and broader than the one figured on the sketches.
The characteristic features are : the parallelism of the striae and
the absence of areas.

Cymbella Cesatii (Plate 28, fig. 17).

I doubt whether this curious diatom ought not to come much
higher up the genealogical scale, anyway after Cymbella angustata,
I place it here only to follow Cleve. It has been assigned to three
genera : to Cymbella, to Encyonema, and to Navicula. It is
very narrow and nearly symmetrical. Its chief characteristic is
the distant terminal nodules. The ends are more or less acute.
Areas indistinct, but the central area is sometimes slightly
rounded. The margins begin undoubtedly to show a tendency
to triundulation, a feature which seems to be transitional to
the next form of our series.

Cymbella gracilis- Cesatii (Plate 28, figs. 14, 15, 16).

This is a very curious form in the Herkimer slide, where it is
fairly numerous, showing rather variable outlines. The areas
begin to be distinct. The terminal nodules are distant from the
ends, perhaps even more so than in Cymbella Cesatii. It is
rhomboidal and sometimes cymbelloid, bent along the longitu-
dinal axis. The striae are radiate, though not so radiate as in
Cymbella Cesatii, and not so dense. It usually shows on the^
median striae a distinct stigma. This gives it a false appearance
of a Gomphonema. It is shorter than Cymbella Cesatii and still
more slender. As I have already mentioned, this may be a new
species.

Cymballa deiicatula (Plate 28, fig. 13).

This form is very similar to the next one, but it is not an
Encyonema. The terminal nodules are not distant and the ends
are acute. The Kev. Wm. Smith points out that it comes very
near to Encyonema Scotica, and so it does.

416 SIR NICHOLAS YERMOLOFF OX. SOME INTERMEDIATE FORMS

Encyonema Scotica (Plate 28, fig. 12).

This form is common both in European and American deposits.
It is too well known to need description. The striae are less
dense and the areas more distinct.

Encyonema gracilis (Plate 27, fig. 10 ; Plate 28, fig. 11).

I describe here only those specimens of this species which are
fossil in the Monmouth and Cherryfield slides. I think I have
made no mistake in the determination, but I am not quite sure :
it comes also very near to Cymhella Yarrensis, figured in Schmidt's
Atlas. On the other hand Cleve states that Cymhella Yarrensis
is a native of Australia and Tasmania, and I am rather averse
to identifying a fossil form from North America with a living one
from southern waters. The specimens are rather large and robust,
the striae pronounced, radiate but parallel at the ends. Axial
area very regularly linear. Ends acute with slightly distant
terminal nodules. Tendency to triundulation slight but
appreciable. No distinct stigma, but on some specimens there is
something like an indistinct stigma. Striae moniliform slightly
decipient. Length as large as 0*07 mm., or even more, therefore
these American fossil specimens are longer than stated by Cleve,
who gives as maximum length 0'056 mm. Striae visible even
under low power. The number of striae to O'Ol mm. seems
identical with the one stated by Cleve : 13 to 0*01 mm. or a
little more.

Cymbella angustata (Plate 27, fig. 9).

This is a very important member of our series. It is fouiid
both in European and American slides. The striae are faint,
radiate, about 16 to O'Ol mm. Ends rostrate-capitate. Margins
usually triundulate. Areas narrow but distinct, and in forms
intermediate to Cymhella Stodderi showing a tendency to become
broader.

About this species there seems to have arisen in the works of
authors some confusion : on Plate XVII, fig. 156, of the Synopsis
of British Diatomaceae, the Rev. Wm. Smith gives a fairly good
drawing of it, but calls it Navicula angustata, which is natural
enough owing to its nearly symmetrical outline. He does not
show any striae. But the whole habit of the species seems

OP THE GENERA NAVICULA AND CYMBELLA. 417

-very true to nature. It seems to be undoubtedly Cymhella
■angustata.

Further, according to Cleve and to van Heurck, it has been

somehow mixed up with Cymhella aequalis or suhaequalis, and

;that seems more inexplicable, seeing that the so-called aequalis

•group, although very akin to angustata, is yet different enough.

Cymhella angustata is undoubtedly a form steadily passing,
^perhaps through the aequalis group, into the American Cymhella
. Stodderi — a living form characterised by rostrate or subrostrate
-ends, broader areas and punctate striae.

Cymbella aequalis and subaequalis (Plate 27, figs. 7,8).

These two forms are so near to each other that it is almost
impossible to distinguish them, and indeed Cleve simply unites

"them together into one species. There seems to be a difference
between them only in the dimensions of the axial area and perhaps
in size. Both these forms have the same chief specific feature,

■which is that the median striae are farther apart (decipient).
Both are rather distinctly asymmetrical, and the ends are rather

-obtuse. Both are common in Europe. I should say that in
America they pass into Cymhella Stodderi, but their striae are

.always much less distinctly punctate. The aequalis group is very
numerous in the St. Fiore slide, where it shows some insignificant

•variations. One of such varieties has been styled by Grunow
var. Florentina, but it seems hardly to deserve a special name.
All these forms are small, not more than 0*04 mm. in length.

'The striation is not so dense as in the American forms. The
w^hole group seems to be very akin, on one side to the angustata
group, on the other to Cymhella Stodderi. I have therefore placed
the aequalis group in the genealogical table as intermediate be-

"tween the angustata and the Stodderi groups.

Cymhella Stodderi (Plate 27, figs. 5, 6).

This species is most interesting from our point of view. It is
"to be found on the Herkimer slide in profusion. Cleve states
"that it also inhabits the White Mountains. It is nearly symme-
■trical, yet still a Cymbella. It has subrostrate ends. The striae
are very punctate, radiate, numbering about 15 or 16 to O'Ol mm.
I cannot understand why Cleve says that it is not distinctly
j^-punctate. On the contrary it is, at least on the Herkimer speci-

418 SIR NICHOLAS YERMOLOFF OX SOME INTERMEDIATE FORMS

jiieus, very clearly punctate. Its chief distinctive feature is the.
area, which is linear-lanceolate, more or less linear and more or
less lanceolate. The Rev. Francis WoUe, in his Diatomaceae of
North America, gives a figure of it on Plate LXIII, fig. 34, but,
this figure is not good : it is too broad, too naviculoid, and the
ends are too rostrate. The area is shown too broad. However,.
there seems to be no other figure extant. Cleve mentions a very
true and very important fact : that Cymhella Stodderi is nearly
akin to Navicula Monmouthiana, and so it undoubtedly is. In.
fact, as soon as Cymhella Stodderi loses the subrostration of its.,
ends and the lanceolate outline of its area, it merges immediately
into Navicula Monmouthiana.

Navicula Monmouthiana- Stodderi (Plate 27, figs. 3, 4).

This is a form intermediate between Cymhella Stodderi and'
Navicula Monmouthiana. The evolutionary transition from is.
Kavicula to a Cymbella is already well marked : the valves have
acquired asymmetry and a slight tendency to subrostration. The-
striae are more punctate and the axial area is broader and more-
lanceolate than on Cymhella Stodderi.

I now come to the final member of the whole series I have-
examined, to Navicula Monmouthiana.

As I have already stated, this last term of the series seems tt^
me to be the prototype of them all, I mean the type to which
all the others are, so to say, pointing. In my opinion, it is the
ancestral Pliocene form. We ought, therefore, not to climb up-
to it from Cymhella microccphala, but on the contrary descend
the ladder in the opposite direction, admitting Motimouthiana as
the first, and microccphala as the last, member of the series..
In my opinion, Navicula Monmouthiana seems to have been the
fossil ancestral parent, from which the whole tribe has derived
if not to say degenerated. Now it is well known that several,
authors admit that (-ymbellae are degenerate Naviculae. This
admission seems plau:ible. I do not like to use the term
" degenerate," because we cannot know the trend and direction
of evolution, yet it appears quite natural to admit that Navicula
Monmouthiana is, so to say, a perfect form, whereas the Cymbellae-
are imperfect forms.

OF THE GKNERA NAVICULA AND CYMBELLA. 419

'Navicula Monmouthiana (Plate 27, figs. 1, 2).

This curious fossil diatom is fusiform. Its average length is
xabout 0 07 mm. Its breadth about 001 mm. Striae very dense,
-parallel in the middle, then radiate up to the ends. The ends
not protracted. Number of striae 16 to 20 to 001 mm. As
;?.ll Entoleiae Naviculae, it has rather convex valves. Fissures
'Comma-like turned in the same direction. Pores rather distant.
The axial area is regularly linear, or I should rather say parallel
-to the margins.

Such is the typical form of Navicula Monmouthiana. This
type form is rare : the great majority of the Monmouthiana forms
on my Monmouth-Cherryfield slides are slightly different, already
showing a first variation from the type form. Although identical
with it in everything else, yet there is this difference, that the
outline or contour of the axial area is not regularly linear, but
.linear-lanceolate ; up to the half of the distance between the ends
and the central nodule this area is linear ; then it gets elongated
and becomes lanceolate. This difference can hardly be considered
unimportant or accidental, because on all such specimens it is
invariably constant.

Now a lanceolate outline of the axial area is a feature peculiar
^0, and very constant in, Cymhella Stodderi. On the other hand
the Stodderi forms are always subrostrate, whereas Monmouthiana
never shows any subrostration at all. I am therefore much
inclined to admit that the Monmouthiana forms I am speaking
about are not exactly N. Monmouthiana, but an intermediate
form between N. Monmouthiana and Cymhella Stodderi. And
-Irom this point of view they are the more interesting, as they
represent an intermediate variation : although very near to
the typical Monmouthiana, yet they have so to say already
moved towards the associated variety, the N. Monmouthiana-
Stodderi.

We have thus travelled, step by step, through the whole series
•of these forms, which, beginning with Navicula Monmouthiana,
•ends with Cymhella microcephala, and which I have proposed
to group under the name of the " Monmouthiana Integral."
This whole group includes many species and varieties, yet they
>:are so nearly connected with one another that it is hardly
•.possible to say where one ends and the other begins.

420 SIR NICHOLAS YERMOLOFF ON SOME INTERMEDIATE FORMS'-

Along the patli of the evolution we actually note the following;
gradual changes :

(1) The ancestral fossil form, N. Monmouthiana, is large^
symmetrical, showing no rostration. Its axial area is broad and
regular. The striation is dense and punctate. From a geometii—
cal point of view the form is, so to say, perfect.

(2) Then the striation becomes less and less pronounced and
dense, and less and less visibly punctate or lineolate. The areas
appear less and less regular and become narrower.

(3) Although none of the forms show any pronounced asym-
metry, yet they become more and more asymmetrical, actuaL
Naviculae transforming themselves into Cymbellae.

(4) The forms seem to gradually acquire first rostrate, theiir
even capitate ends.

(5) The forms gradually become reduced in size.

(6) At the end of the series, Cymhella microcephala shows no
hyaline area at all. It is of very small size, has rostrate-capitate-
ends and very faint striae.

Such seems to have been the march of evolution and of changes
in the forms. The naviculoid form seems to have lost its perfect-
outline and become a Cymbella, losing symmetry and size and
acquiring, perhaps at the expense of striation, dilferences in the
shapes of the ends. I am therefore strongly inclined to think
that indeed the whole process has been a sort of " degeneration "
from a simple and perfect form to varied and complex forms. I
again repeat that I do not like to use the term " degeneration,"
because we cannot know the trend of evolution. I therefore
use this term only for convenience sake.

After all, the above trend of changes seems to be natural enough^
being perhaps a logical and inevitable result of the more complex
conditions of life appearing on our planet and establishing them-
selves on the globe after the Glacial periods. After all, the same
trend of changes, from large, uniform and simpler forms to smaller,
more varied and more complex ones, seems to have affected the-
whole of organic life. No wonder therefore that the same trend
has wrought similar changes in Diatoms. It has actually beea.
a transition from homogeneous to heterogeneous forms.

Thus a minute study of systematics seems to have helped us
on towards regions of generalisation. I therefore consider that
systematics are certainly not the dry and useless work they seenii

J)

5>
>J

55
J5

OF THE GENERA NAVICULA AND CYMBELLA. 421

to some : on the contrary, they are necessary, and fruitful of
larger results, and every Systematist, with his minute and
laborious examinations, brings his contribution towards the;
construction of the great building of scientific knowledge.

Description of Plates 26-28.

Plate 26.

Fig. 1. Navicula Momnouthiana Grun.

2. Navicula Monmouthiana Grun.

3. Navicula Monmouthiana- Stodderi.

4. Cymhella Stodderi Cleve.

5. Cymhella Stodderi Cleve.

6. Cymhella aequalis W. Sm.

7. Cymhella aequalis W. Sm.

8. Cymhella angustata W. Sm.

9. Cymhella {Encyonema) gracilis Rabh.

10. Cymhella [Encyonema) Scotica W. Sm.

11. Cymhella delicatula Kiitz.

12. Cymhella {Encyonema) graciUs-Cesatii.

13. Cymhella Cesatii Rabh.

,, 14. Cymhella microcephala Grun.

Plate 27.

(Magnification : Figs. 1-9, x 1200 ; Fig. 10, x 700.)

Fig. 1. Navicula Monmouthiana Giun. Type form (Cleve). Mon-
mouth. L. 0-07, B. 0-01. Fusiform. Striae 16 (middle)
to 20 (ends) in O'Ol mm., nearly parallel in middle,
radiate at ends. Central pores distant. Area regu-
larly linear or rather parallel to margins. Ends show
no tendency to subrostration.
,, 2. Navicula Monmouthiana Grun. Monmouth, Cherryfield.
. L. 0-07, B. 0-01. Striae 16-20 to O'Ol mm., parallel in
middle, radiate towards ends ; ends not subrostrate,
though showing sometimes a tendency to subrostration.
Area linear-lanceolate.
3. Navicula Monmouthiana- Stodderi {Navicula Monmouthi-
ana nearly passing into Cymhella Stodderi) . Herkimer.
L. 0*05. Striae 18 to O'Ol mm., punctate and radiate.
Raphe nearly straight. Pores distant. Nearly sym-

5 5
55
55

)5

)}

422 SIR NICHOLAS YERMOLOFF OX SOME INTERMEDIATE FORMS

metrical. Not subrostrate. Fusiform. Terminal fis-
sures comma-like turned in same direction. Area
linear-lanceolate.
Fig. 4. Navicula Monmouthiana-Stodderi (intermediate between
N. Monmouthiana and Cymbella Stodderi). Herkimer.
L. 0-07, B. O'Ol. Striae 20 in O'Ol mm., radiate, punc-
tate. Fusiform, nearly symmetrical. Ends slightly
subrostrate. Terminal fissures comma-like. Central
nodule slightly eccentric.
-,, 5. Cymhella Stodderi Cleve. Herkimer. L. 0*06. Striae 18
in O'Ol mm., punctate and radiate. Ends subrostrate.
Terminal fissures turned in same direction, comma-like.
Area lanceolate, not abruptly dilated towards centre.
Slightly asymmetrical.

6. Cymhella Stodderi Cleve. Herkimer. L. 0-072, B. 0*01.
Striae 15 in 0*01 mm., radiate, punctate. Fusiform,
slightly asymmetrical. Ends subrostrate. Axial area
rather broad, lanceolate, not abruptly dilated toward
centre. Very near to N. Monmouthiana.

7. Cymhella aequalis W. Sm. {suhaequalis Grun.). St. Fiore.
L. 0*04. Striae 10 in middle, 14 at ends, radiate,
decipient, puncta indistinct. Lanceolate, subrostrate.
Area just distinct.

^, 8. Cymbella suhaequalis Grun. {aequalis W. Sm.). Premnay
Peat. L. 0'04. Striae 12-14 in O'Ol mm., radiate,
obscurely punctate, decipient. Ends obtuse or trun-
cate, subrostrate. Raphe almost straight surrounded by
hyaline zone rather broad, dilated round central nodule.
,, 9. Cymhella angustata W. Sm. Herkimer. L. 0'04. Striae
16 in 0*01 mm., radiate, very faint. Ends rostrate-
capitate. Margins triundulate. Axial area narrow but
distinct.
^, 10. Cymhella {Encyonema) gracilis Rabh. Monmouth,
Cherryfield. L. 0*06, B. 0*01. Striae 13 in 0*01 mm.,
radiate, moniliform. Margins slightly triundulate.
Axial area linear, central area absent. Raphe slightly
nearer to ventral margin. Central nodule on dorsal
side. Ends subrostrate. Terminal nodules slightly
distant from acute ends. Striae on fossil forms robust ;
median stria on ventral side with indistinct stigma.

>5

JOURN. Q. M. C.

Ser. 2, Vol. XIII, PL 26.

3

6

8

9

10

11

12

13

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The " MoNMouTHiANA Integeal.^'

Adlard 4" So7i ^ West Newmav, Ltd.

Journ.Q.M.C.

Ser. 2yoijau,pi.27.

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Variation in the genera Navicula-Cymbella.

Joiirn.Q.M.C.

Ser. 2.VolXIII,Pl,28.

11

12

13

14.

5 g

15.

16

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17.

18

19.

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Adlard &. Son & West. Newman Ltd.litli.

Variation in the genera Navicula-Cymbella.

?J

OF THE GENERA NAVICULA AND CYMBELLA. 423

Plate 28.

(Magnification: Fig. 11, x 700 ; Figs. 12-19, x 1200.)

Fig. 11. Cymhella {Encyonema) gracilis Rabli. Monmoutli. L
0-07, B. 0-009. Strio,e 13 in 0*01 mm., radiate, at
ends parallel, moniliform. Axial area linear, no cen-
tral area. Terminal fissures a sliojht distance from
ends. Slightly triundulate. Striae robust. No
stigma. Ends acute. Central nodule on dorsal side.

12. Cymhella (Encyonema) Scotica W. Sm. Premnay Peat.
Herkimer. L. 0*04, B. O'OOS. Striae 13 in O'Ol mm.,
radiate, lineate. Terminal nodules distant from ends,
turned downwards. Raphe much nearer to ventral
margin. Dorsal margin arcuate, ventral margin
nearly straight. Median stria on dorsal side with
stigma appearing to coalesce with central nodule.
Ends acute turned to ventral side. Hyaline zone
distinct, elongated round central nodule.

13. Cymhella delicatula Kiitz. Herkimer. L. 0*04, B. 0*005.
Striae radiate, very delicate. Median stria on dorsal
side with distinct stigma. Ends acute. Terminal
nodules near ends. Ventral margin slightly arcuate,
dorsal margin arcuate. Hyaline zone very narrow, not
dilated. Central nodule on dorsal side. Intermediate
with Encyonema Scotica and very similar to it.

14. Cymhella [Encyonema) gracilis-Cesatii. Herkimer. L.
0'04, B. 0'005. Rhomboidal, cymbelloid, ends acute.
Terminal nodules distant. Striae 20 in 0"01 mm.,
radiate, punctate. Median stria on dorsal side
with distinct stigma. Central nodule on dorsal side,
ventral margin slightly gibbous, dorsal margin convex.
Areas indistinct. Terminal fissures comma-like, bent
towards ventral side. Sometimes still narrower and
longer.

15. Cymhella (Encyonema) gracilis-Cesatii. Herkimer.
L. 0-045, B. 0-0045. Striae 18 in 0*01 mm., radiate,
punctate. Rhomboidal, ends acute, terminal nodules
distant from ends. Central nodule on ventral side.
Ventral margin slightly triundulate, dorsal margin

JOURN. Q. M. C, Series II.— No. 83. 32

1^

»j

424 SIR NICHOLAS YERMOLOFF ON NAVICULA AND C YMBELLA.

convex. Median stria on ventral side with stigm-'^.
Areas narrow but distinct.
Fig, 16. Cymhella {Encyonema) qracilis-Ccsalii. Herkimer. L.
0*05, B. O'COo. Striae 18 in O'Ol mm., radiate,
punctate. Ends acute. Median stria on ventral side
has a punctum, so that the stria appears to coalesce
with nodule. Ventral margin slightly triundulatc,
dorsal margin convex. Areas distinct. Terminal
nodules distant from ends. Sometimes more rhom-
boidal and more cymbelloid. Resembles Encyonema
gracilis.

,, 17. Cymhella {Encyonema) Cesatii Rabh. Premnay Peat.
L. 0-06, B. 0-006. Striae 19 in O'Ol mm., faint, radiate,
no punctum on medium stria. No axial area ; central
area small and rounded. Very slender, symmetrical,
slightly triundulate, especially one of the margins.
Terminal nodules distant from ends.

,, 18. Cymhella microcephala Grun. St. Fiore. L. 0*025,
B. 0*004. Striae about 25 in 0*01 mm., very faint,
nearly parallel. Ends rostrate-capitate. Areas in-
distinct. Asymmetrical.

,, 19. Cymhella microcephala Grun. Premnay Peat. L. 0*03.
Striae 25 in 0*01 mm., faint, punctate, nearly parallel.
Asymmetrical, ends rostrate-capitate. Areas distinct.

Journ. Quckelt Microscopical Club, Ser. 2, Vol. II J I., So. 83, November I'Jli.

425

A FURTHER CONTRIBUTION TO OUR KNOWLEDGE
OF THE TWO AFRICAN SPECIES OF VOLVOX.

By G. S. West, M.A., D.Sc, F.L.S.,

Mason Professor of Botany in the University of Birmingham.

{Read April dth, 1918.)

Plates 29 and 30.

Some few years ago the author published a paper * on " Some
New African Species of Volvox," described at that time exchi-
sively from vegetative individuals. One of these, Volvox Rousse-
letii, is the largest known species of the genus and was obtained
by Mr. Rousselet from a pool near Gwaai in Rhodesia in September,
1905 ; the other species, F. ajricanus, was collected by Mr. R. T.
Leiper in Uganda in July 1907.

Since then Mr. Rousselet has obtained some plankton-material
collected by Dr. Jakubski of Lemberg (Lwow) from small tem-
porary pools in the Ussangu Desert in the African region formerly
known as "German East Africa," and in this materialwere present
sexual colonies of the above-mentioned African species of Volvox.

Although the vegetative characters were amply sufficient tO'
establish these two species, great interest is naturally attached to
the discovery of their sexual colonies, since it assists in completing
the description of these African types of Volvox and shows still
more clearly that they are distinct races as compared with the
European types.

Mr. Rousselet has published a preliminary note f stating how
he obtained these sexual colonies in 1914 and that they had been
submitted to me for detailed investigation.

The sexual colonies have been photographed and a selection of
these photographs appear on the accompanying plates. Unfor-
tunately, no male colonies of V. africanus were found in this East

* G. S. West in Journ. Quek. Micr. Club, ser. 2, vol. xi., Nov. 1910,
pp. 99-104.

t C. F. Rousselet in Journ, Quek. Micr. Club, ser. 2, vol. xii., Nov.
1914, pp. 393-394.

42G

G. S. WEST ON

Afiican material, althougli from a previous observation on material
from Ugcinda it seems probable that the male colony is similar
to that of F. aureus * On the other hand, both male and female
colonies of F. Rousseletii were abundant. The outstanding feature
in both species is the relatively large number of ripe oospores in
the female colonies. In F. Rousseletii not only were there purely
male colonies (figs. 1 and 7), but also male colonies which, in addi-
tion to numerous antheridia, possessed daughter-colonies which
had arisen from parthenogonidia (fig. 2).

There is a marked polarity in all the sexual colonies. The
vegetative colonies of F. Rousseletii are approximately spherical,
but both male and female colonies are egg-shaped with a general
concentration of the sexual elements towards the narrower pole
(consult all the figures of colonies).

The following tabulated statements indicate the difi'erences
between the two African species :

Volvox Rousseletii.

G. S. West.

Vegetative colonies subglobose ;
diameter, 1,125-1,240 ^t.

Number of cells, 25,000-50,000.

Cells small, very densely aggre-
gated, 4-6'5 /Lt in diameter, some-
what angular with relatively broad
connecting strands of protoplasm.

Daughter-colonies, regularly 8.

Oospores, 120- 150 (average 12 8),

densely clothed with strong conical

spines ; average diameter without

spines, 44 /i ; length of spines,

11-12 ft.

Androgonidia (and subsequently
antheridia) very numerous in each
male colony (usually several
hundred).

Antherozoids and oospheres
produced in different colonies.

Volvox africanas.
G. S. West.

Vegetative colonies ovoid-
ellipsoid ; length, 345-610 fi;
breadth, 295-480 /x.

Number of cells, 3,000-8,000.

Cells less densely aggregated,
8-9"5 fi in diameter, almost glo-
bose with long delicate connecting
strands of protoplasm.

Daughter-colonies, 1-4.

Oospores, 70-80 (average 74),
with a thick smooth wall ; aver-
age diameter, 45 /u.

Androgonidia not yet observed
with certainty (but probably very
numerous).

Antherozoids and oospheres
produced in different colonies ?

[This is probable, since only
female colonies have so far been
definitely observed.]

* G. S. West, I.e. p. 103.

THE TWO AFRICAN SPECIES OF VOLVOX. 427

The characters set out in the above table clearly show that
y. Rotisseletii and V. africaniis are two species differing very
much from each other both in their vegetative colonies and
in their oospores. It is interesting, however, to compare these
African species of Volvox with the two well-known European
species.

V. Rousseletii is without doubt the African species comparable
v.ith F. glohator of Europe. It differs from the latter vegetatively
in its larger colonies and in the much greater number of their con-
stituent cells, which are far more closely aggregated. The sexual
differences are equally well marked. The antlieridia are much
more numerous and apparently are not developed in the same
colonies as the egg-cells. In the female colonies the ripe
oospores are about four times as nimierous as in F. glohator
and they show a decided concentration towards one pole of
the colony (fig. 8). Moreover, the wall of each oospore is fur-
nished with long conical spines (consult fig. 3) , very different
in appearance from the depressed conical warts on the oospores
of F. glohator.

F. africanus affords a comparison with F. aureus not unlike
that between F. Rousseletii and F. glohator. It differs vegeta-
tively from F. aureus in the ovoid-ellipsoid shape of its colonies,
in the larger number of constituent cells, and in the nature of the
daughter-colonies. The latter vary from 1 to 4 (commonly 3) in
number, are of large size and ovoid form, and become flattened by
compression, whereas in F. aureus there are from 4 to 14 daughter-
colonies of approximately spherical shape. It seems probable that
the male colonies of F. africanus are similar to those of F. aureus,
but the female colonies differ in the presence of a much larger
number of ripe oospores, averaging 74 in F. africanus as against
6 in F. aureus. In both these species the walls of the ripe oospores
are thick and smooth.

Explanation of Plates 29 and 30.

Pigs. 1-3. Volvox Rousseletii. 1, male colony showing the ovoid
form and the large number of antheridia concentrated
towards the narrower end, x 50. 2, male colony with
antheridia and young daughter-colonies, x 50. 3, out-
line of spiny oospore, x 500.

428 G. S. WEST ox THE TWO AFRICAN SPECIES OF VOLVOX,

Figs. 4-6. Volvox africanus. 4 and 5, female colonies with
ripe oospores, x 74. 6, outline of ripe oospore, x 500.

JFigs. 7 and 8. Volvox Rousseletii. 7, male colony showing
marked polarity in respect of the antheridia,x 50. 8,
female colony with large number of ripe oospores and
also showing polarity, x 50.

journ. QuckcU Microscopical Club, iSer, 2, Vol. XIII,, No. 83, yovembtir 1j.

429

THE BINOCULAR MICROSCOPE.

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

{Read October Sth, 1918.)

Among microscopists there are some who regard the binocular
merely as a toy or plaything, while others take it more seriously and
consider it an instrument useful in scientific research. The bulk
of microscopes in use are, however, monoculars. This no doubt
is partly due to the less cost and greater portability of the mono-
cular instrument, and partly to the failure of the Wenham and
Stephenson binoculars with high-power objectives, which of course
means that if high- power work had to be done, one could not get
on with a binocular alone, a monocular would have to be added
to the outfit ; the purchase of two microscopes instead of only a
monocular would necessarily deter many from even thinking of
l>uying such " a useless plaything as a binocular."

A pertinent question has been asked, " What discoveries have
been made with a binocular ? " It must be admitted that so far
it is difficult to point to any. Before this note is finished we trust
that a satisfactory answer will, for the first time, have been found
to that question, first asked byHooke 250 years ago. To proceed
to our investigations, let us take the Greenough as our standard
instrument. It consists, as you are all aware, of two erecting
microscopes inclined to one another at the normal inclination of the
eyes at 10 inches, viz. 14 J°. This yields the perfect ortho- stereo-
scopic image. Hitherto there has been no standard to Avhich a
stereoscopic image could be compared to determine if the relief
in the image was too high or too low. In this instrument the
full apertures of both objectives are clear, and the illumination
in the tubes is the same. The Wenham is so well known that a
description is unnecessary.

430 EDWARD M. NELSON ON

A third binocular is the new Parallel tube; * it, like theWenham,
uses a single objective. Three kinds of vision can be obtained
with this instrument, viz. non-, pseudo-, or ortho-stereoscopic,
which is effected by adjusting the separation between the tubes
either equal to, greater, or less than that of the interpupillary
distance of the observer's eyes. In this microscope, which some
of you may have seen, the illumination in each tube is nearly the
same. When the tube separation is equal to that of the inter-
pupillary distance, the whole of the pencils emerging from the
eye-pieces pass uninterruptedly through the pupils of the eyes,
the image therefore has its maximum brightness, and is non-
stereoscopic. But when the tubes are closed to about 1 mm. less
than the interpupillary distance, the inner portion of the emergent
pencils are cut out by the iris of the eyes, the image becomes
ortho- stereoscopic and loses brightness.

This reduction in the brilliancy of the image is a guide in setting
the tubes to their proper separation for ortho-stereoscopic images.
If we examine the same low- power object with a Greenough and
a Wenham, arranging matters so that the measured magnifying
povNTcrs are identical, we shall find the stereoscopic relief in the
image given by the Wenham is a good deal below that of our
standard ; as the powers increase, this deficiency becomes less.
The falling off in the relief of the image in a Wenham mth powers
ranging from 1 inch downwards is an important point scarcely
noticed by microscopists ; on the contrary, the Wenham together
with the Stephenson are regarded by them as instruments yielding
perfect ortho-stereoscopic images. Now, if attention be directed
to the apparent size of the images, that in the Wenham will be
noticeably larger than that in the Greenough, althougli the
measured powers are identical. The Parallel tube binocular was
now set up, and the powers increased to Greenough 46, Wenham,
44, Parallel tube, 42. The amount of relief in the Greenough and
Parallel tube was the same, and in each of them it was greater
than in the Wenham, but the apparent magnification was much
greater in the Parallel tube, next in the Wenham, and least of all
in the Greenough.

♦ Felix Jentzach, Ph.D., "The Binocular Microscope," Journ.
R.M.S., 11H4, pp. 1-16.

THE BINOCULAR MICROSCOPE. 431

Similar results were obtained when the powers were further
increased to 76, 73, and 71 diameters respectively, with the
exception that wdth the Wenham there was less falling off in the
relief. It is remarkable that the observed difference in the stereo-
scopic relief depends to some extent upon the objects on the stage.
For example, if the objects are the inside and outside views of
Triceratium fimbriatum there will be no very great difference in
the stereoscopic relief in these three instruments, but let this
object be exchanged for some polycistines, a considerable difference
in the strength of the stereoscopic effects will at once be apparent.
It is therefore most important that anyone, when comparing the
stereoscopic relief in different kinds of binoculars, should take care
to have a suitable object upon the stage.

There is another interesting point worth notice, viz. if an object
under a Greenough be examined with only one eye, and a mental
estimate of its size be made, then the eye removed from the
instrument and distant objects about the room looked at for a
few seconds, afterwards the object under the microscope again
examined, but this time with both eyes, the image will appear
smaller than when seen by only one eye. With the Wenham
there is not this difference, but with the Parallel tube instrument
the difference is the other way, the image seen with both eyes
being larger than that seen with one eye. It is necessary to focus
the eyes upon things in the room before each separate experiment
is made.

As to the ease and comfort of vision, to my eyes the Greenough
and Wenham are similar, while that in the Parallel tube is not
quite so comfortable, when it is arranged for ortho-stereoscopic
images, because of the necessity of keeping the head perfectly
steady, so that the emergent pencils may be equally cut by each
eye. This discomfort increases with the higher powers, as the
emergent pencils get smaller. This certainly is the defect in all
those kinds of instruments where the stereoscopic relief depends
upon the cutting of the emergent pencils by the iris of the eyes.
It is not a very serious one ; if caps with stops cutting out about
one- quarter of the aperture with low eye- pieces, and about one-
third w^ith high ones, are placed over the eye-pieces, vision is
thought to be easier. This plan of using caps with stops over

432 EDWARD M. NELSON ON

the eye-pieces for producing stereoscopic \'ision is due to Wen-
ham. There are those who are unable to combine the images,
even in a Greenough, but who have no difficulty in doing so in
a Parallel tube binocular ; while the experience of others is just
the reverse. It is probable that less than half those who use
microscopes are able to see a stereoscopic image in a microscope,
or in any other optical instrument. With regard to the sharpness
of the images, those in the Greenough and Parallel tube were very
similar, and both were sharper than those in the Wenham. The
difference in the apparent sizes of the images in those three
binoculars is due to the fact that the apparent distances of the
projected pictures are different. With the Parallel tube binocular
the eye sees the virtual images projected to a greater distance
than with the convergent tubes of the Greenough. It has been
stated that there is no definite measurable distance for the
plane of the virtual image, but obviously these experiments
prove that with a binocular it is not so.

As 76 is the highest power with my Greenough, the following
experiments will be confined to the other two binoculars. The
object used in the previous experiments was a common circular,
and not quite spherical, polycistine, mounted opaque, and illumin-
ated by a side reflector ; but as we are now about to deal with.
higher powers, a more suitable object must be used. A good one
is a diatom, formerly called Actinosfhenia splendens, but now
known as Actinoptycus. Strictly speaking, it is an Aulaco-
discus, it has ten convex rays, down the centre of each runs a
true " aulax," ending in a small process. When this is examined
with, say, a 1-inch objective on a dark ground with a condenser of
low angle, or a spot lens, the aulax is seen as a bright white line,
but with a condenser of larger angle it becomes a black line.
The reason for this is not understood.

This aulax is, by the way, an excellent test when viewed upon
a dark ground for medium objectives, say 2/3 and 1/2. When
this diatom was placed under the Wenham, power 270 and dark
ground, the aulax when in a horizontal position was sharply
defined, but when in a vertical one it was poorly imaged. In
the Parallel tube instrument, under the same power, the aulax
was sharply defined in all directions. This test is a good one

THE BINOCULAR MICROSCOPE. 433

^because it deals with the coarse features of a fairly large
diatom and not with periodic structures, such as striae, secondary
markings, etc. As a test with striae a moderately fine Navicula
■lyra may be used. The Parallel tube instrument will resolve the
transverse striae when the valve is in any direction, while the
Wenham will only do so when the valve is vertical, or nearly so.
■ The stereoscopic relief in these experiments was stronger in the
Parallel tube binocular.

Let us now examine a Coscinodiscus radiatus, which is an excep-
tionally flat diatom. The Parallel tube binocular revealed a
feature never before observed, viz. that the "Omphalos" is at
the bottom of a small pit. Some other diatoms were then
examined with reference to this detail, and some other Coscinodisci
were found to have similar pits, an Arachnoidiscus ornatus from
Japan had one also. The diatom was then examined under a
similar power (270) in the Wenham. Knowing that this little
pit existed, its presence could be recognised, but it is doubtful
if it would have been discovered if its presence had not been
known. The fact that it has never been previously seen proves
that this is so.

The Parallel tube binocular has revealed another feature of this
diatom, viz. that its floor is anything but flat ; parts are raised and
parts depressed, this quite irregularly and not in any symmetrical
pattern. By way of illustrcition, suppose some pastry dough had
been spread smoothly on a table, and that some children had
■ come when the cook was not looking and had pressed in portions
of the dough with their fingers and hands. If a layer of empty
honeycomb cells could have been treated in the same way as the
soft dough, we should have a fair representation of the surface
of this diatom, which hitherto has been thought to be flat. The
spread slide, which contains this diatom, was bought in the year
1868; it has been kept fifty years in a special box of test objects,
and not in the diatom cabinet. It is quite impossible to say how
many hundreds of objectives have been tested on it, but probably
there is nowhere a diatom slide that has been worked over to
anything like the same extent as this one. Imagine then my
-surprise on seeing quite a new aspect of this well-studied
<^C. radiatus. It was as great as if I had found the hours on my

434: EDWARD M. NELSON ON

watch paiuted in Arabic figures, when I have known them a.s=
Roman for the greater part of my life.

It has been found that upon the outside of this diatom the
larger areolations belong to the depressed portions, and the smaller-
ones to the raised ; of course when an inside view is obtained the
reverse is seen. These features have neither been seen, nor could
have been found, with a monocular, but when known they can
be detected with a Wenham, but it is very doubtful if ever they
would have been discovered with that instrument. It is a very-
different thing to discover an object whose presence is unknown,,
and to find it when one both knows that it is there and knows •
what to look for.

This then is the answer to the question, " What detail has been,
discovered with a binocular that has not been seen with a mono-
cular ? " It is perfectly certain that this structure would never
have been discovered with a monocular.

Perhaps someone will ask, " "What light does the new binocular-
throw upon the interpretation of the Podura scale ? " The Podura
scale has undergone a more searching microscopical examination
than any other object, and yet it remains the microscopist's.
enigma. In a paper on this subject * the various views of several
observers were given, besides that of my own, which was that the
exclamation mark was a cuniform- shaped elevation and not a
plumelet. It has now been examined with an apo . 1/12 of 1 '4 N. A.
and No. 18 compensation eyepieces on the Parallel tube binocular..
From an examination of this kind one would have expected an.
immediate and decisive answer, but this was not to be had, for
the object is a very thin one, and such objects, as has been already
pointed out, do not yield much stereoscopic relief. Of course-
nothing could be easier with either a monocular or binocular, by
means of a small cone, to make a strong image of a raised exclama-
tion mark, but would it be a true image ? The evidence supplied
by the Parallel tube binocular is that they are depressions. Sup-
pose there is a surface of cheese with grooves or furrows, more or
less parallel, on it, then if with a cheese-taster some scoops be made
in these furrows, with a small and slightly deeper depression at
the end, we shall have a rough representation of this object as-
♦ R. M. S. Journ., 1907, p. 393, pi. 16.

THE BINOCULAR MICROSCOPE. 435

^seen in a Parallel tube binocular. Dra^Ying3 and pliotomicro-
-graplis of many microscopical objects are of little value, the things

that are vv^anted are models of the structures. We want models
of diatoms and models of insect scales. I put forward no definite
-opinion upon the structure of the Podura scale, and still keep
-^n open mind regarding it ; all that can be said is that this
'depression image is a fair description of the appearance of the
^exclamation marks as viewed critically under a Parallel tube
i-binocular. The exclamation mark is an enigma still, and no one

has any pretext for saying, "I know all about the Podura scale,
i^or I have examined it under a high-power binocular."

"Those who have read iwy former paper on binoculars * will

notice that my views have undergone modification. At the time
'of writing it the Parallel tube binocular had been only three months

in use, but now it has been fairly constantly employed for four

years. Previously, in company with many other microscopists,

I was obsessed with the idea of the perfection of the Wenham

binocular images, and had not adopted at that time the Greenough
;image as a standard for stereoscopism. It will be seen, from

what has now been written, that the superiority of the images in
"the Parallel tube binocular is recognised both as regards their

sharpness and stereoscopic relief.

In conclusion, one improvement for the Parallel tube binocular

anay be suggested, which may with advantage be adopted when
•-that instrument is made, let us hope, in this country. At present

■the tube separation adjustment is effected by rack and pinion,

wliich is far too quick ; a movement by a right- and left-handed
■ screw would be more delicate and far preferable. I regret that,
-owing to my not possessing a Stephenson's binocular, experiments

with that instrument have not been included, but there is no
ixeason to doubt that the results would have been precisely

similar to those obtained with the Wenham.

J^Ew Points of Microscopical Interest Brought Forward

!1. The adoption of the Greenough as a standard for stereo-
scopic relief.

-.*

Q. M. C. Journ., 1914, vol. xii., No. 95, p. 378.

436 EDWARD M. NELSON ON THE BINOCULAR MICROSCOPE:.

2. Different kinds of binoculars, with identically the saine^

measured magnifying powers, yield different apparent
magnified images.

3. While some objects show little, if any, diff'erence in stereo-

scopic relief with' different kinds of binoculars, other objects
show much difference.

4. Different kinds of binoculars show different apparent magni-

fying powers when one eye or two eyes are used.

5. The "aulax" in an Actinosphenia splendens is white on a

dark ground if the angle of the substage condenser is
low, but black if the angle is wide.

6. A pit and unevenness in the floor of Coscinodiscus radiatusr

is discovered with a Parallel tube binocular.

7. Fine adjustment for setting the interpupillary distance ol

tubes in Parallel tube binoculars.

Journ. Queketl Microscopical Club, Ser. '2, Vol. XIII , JVo. 83, November 1918.

JOUEN. Q. M. C.

Ser. 2, Vol. XIU, PL 29.

Phofomicrogr. G. S. Wei<f.

Figs. 1-3, V. Ruusseletuj Figs. 4-6, V africamis.

Adhird 4- Son ,)■ 1^'eM Newma}i, Ltd.

JOURN. Q. M. C.

Ser. 2, Vol. XIII, PI. 30.

/

7^ %

Photomicroyr. 6. S. W/ssf.

8

Figs. 7 and S, V. Rousseletii.

Arllard 4- Son <|- Jf'e.s;' Neirmah, Lid.

437

NOTES.

MICROSCOPE EYE-PIECES.

LONG TUBE.

Number ....

A X 5

Bx 7i

C X 10

D X 20

E X 30

Focus

50-8

33-8

25-4

12-7

8-46

r

QO

CO

00

+ 16-7

+ 11-2

s

-15-4

-10-6

- 8-1

- 5-6

- 3-7

Diameter

19-0

14-0

110

6-0

4-0

Hole in diaphragm

24-0

19-0

150

5-0

3-0

R . . .

00

GO

00

+ 67-0

+ 54-0

S

-39-0

--29-0

-230

-16-0

-10-9

Diameter

320

28-0

23-0

10-0

8-0

Distance between surfaces .

57-7

39-4

29-2

15-3

10-9

Field lens down from top of

tube ....

54-6

48-3

21-6

7-0

2-4

SHORT TUBE.

Number ....

X 5

X 7i

X 10

X 20

X 30

Focus

37-6

25-06

18-8

9-4

6-2 6

r

00

00

+ 24-0

+ 12-1

+ 8-1

s

-11-3

- 7-8

- 8-0

— 41

-2-7

Diameter

12-0

10-0

9-0

4-0

3-0

Hole in diaphragm

130

10-0

7-0

4-0

2-5

R . . .

GO

00

+ 66-0

+ 51-0

+ 41-0

S

-29-0

-21-7

-23-5

-12-3

-8-7

Diameter

20-0

20-0

160

8-0

6-0

Distance between surfaces

43-4

29-3

23-0

12-3

8-4

Field lens down from top of

tube ....

37-3

21-3

14-8

3-9

0-5

Measurements are in mm.

Glass : Eye Lens, Chance hard crown, n = 1-5175 v= 60'5.

Field Lens, Chance extra light flint, n = 1-5333 v = 48'5.

Edward M. Nelson.

438 NOTES.

OIL-IMMERSION DARK-GROUND ILLUMINATOR.

N.A. 1*45, Equivalent Focus 69 mm.

'This dark-ground illuminator, after Stephenson, is of a very
simple construction, and in use is most efficient. Its equivalent
focus is 6*9 mm., which enables it to yield a large image of the
source of light. Its N.A. is full 1'45, which is greater than
any dark-ground illuminator now made. Kadius, 18"5 mm. ; this

(Figure full size.)

surface to be silvered. Flattop, 8'06 mm. in diameter. Diameter
-at bottom, 21*5 mm. Thickness, 3*0 mm. Thickness of com-
plete plano-convex lens before top is cut off, 3'44 mm. Diameter
of stop, 11 '5 mm. It is most important that the thickness should
be worked exactly true to the formula.

Glass: Chance dense flint, n = r6225 v = 36*0.

EDWArD M. Nelsox.

439

PROCEEDINGS

OF THE
QUEKETT MiCROSCOPlCAL CLUB.

At the 533rd Ordinary Meeting of the Club, held on April 9th,
1918, the President, Dr. A. B. Rendle, M.A., F.R.S., F.L.S., in
the chair, the minutes of the meeting held on March 12th were
read and confirmed.

Messrs. Wm. Moore Tipping, A. Harry Matthews Fox and
Ernest J. Vickery were balloted for and duly elected members
of the Club ; nomination forms were read on behalf of two for
the fii"st time.

The Secretary announced that the first excursion of the Club
would be to the Royal Botanic Gardens, Regent's Park, on
Saturday, April 13th, that there would be a Gossip Meeting on
the 23rd inst., and that at the next Ordinary Meeting on May Mth
Mr. F. Martin Duncan would give an address on "Insects as
Transmitting Agents of Disease," illustrated by lantern slides
and prepared specimens.

The President then called upon Sir Nicholas Yermoloff, K.C.B.,
to read his paper on " Some Intermediate Forms of the Genera
Navicula and Cymbella."

Sir Nicholas said : — All students of Diatomology are invariably
impressed by the immense number of forms, species, subspecies
and varieties described, named and classified. The differences
which have led to the creation of new forms are sometimes very
trifling and uncertain, based upon personal impressions of ob-
servers, and consequently a maze of confused synonymy has
arisen. From time to time various distinguished authors have
tried to remedy this state of things, striving to reduce the existing
number of admitted species and varieties. Such regroupings
have been attempted by Cleve as regards the genus Navicula,
by Cox and Rattray as regards Coscinodiscus. One such writer

JouRN. Q. Ivl. C, Series II.—No. 83. 33

440 PROCEEDINGS OF THE

has said : " The reduction of the enormous catalogue of species
of Diatomaceae is a consummation devoutly to be wished." I
am not so sure that it is to be so devoutly wished as that. It
seems to me that the careful labour of registering minutiae and
the consequent subdividing of Diatom systematics has been both
fruitful and inevitable. What we should rather wish for is not
a curtailing of the differentiating operations, but a process of
synthetic integration, undertaken, and only possible, after the
study of variations has been thoroughly carried out. The varia-
tions of intermdiate forms of Diatoms are by no means abrupt ;
they pass insensibly from one form into another. An attempt
at synthetic integration forms the subject of this paper.

An American fossil freshwater Diatom — Navicula Monmouth-
iana — may be considered as an ancestral form of a whole series
of Cymbella species. This ancestral form seems to have passed,
through the coui'se of many centuries, through a long series of
slight transformations, evolving several forms of Cymbellae ex-
tremely similar to each other, and closing the series at a very small
form called Cymbella microce-phala.

Sir Nicholas then pointed out by means of lantern slides the
gradual evolution through various intermediate forms of Cymbella
microcefhala from N . Monmouthiana, describing in detail the
various points of similarity and difference between one member
of the series and the next. A series of nineteen drawings of the
various species and varieties dealt with was also shown.

After remarks had been made by the President and Messrs. H.
Morland, N. E. Brown, D. Bryce, and Dr. Leeson, a hearty vote
of thanks was accorded to Sir Nicholas Yermolofi for his inter-
esting paper.

The President then called upon the Secretary to read Prof.
G. S. West's paper, " A Further Contribution to our Knowledge
of the Two African Species of Volvox." In 1910 the author
described, from vegetative individuals only, two species of African
Volvox, F. Rousseletii and V. Ajricanus. Since that time their
sexual colonies have been discovered. Unfortunately, no male
colonies of F. Ajricanus were present in the new material, but
both male and female colonies of F. Rousseletii were abundant.
Prof. West gives a table showing the characters of the two species
and then makes an interesting comparison between them and the
two well-known European species, F. globator and F. aureus.

QUEKETT MICROSCOPICAL CLUB. 441

Mr. Scoiirfield drew attention to this comparison, and stated
that the European species were also to be found in Australia.

The President then proposed a vote of thanks to Prof. West
for his valuable and interesting contribution.

At the 534th Ordinary Meeting of the Club, held on May 14th,.
1918, the President, Dr. A. B. Kendle, M.A., F.R.S., F.L.S., in

the chair, the minutes of the meeting held on April 9th were
read and confirmed.

Messrs. Geo. Thomas Ilollis and Edgar W. F. Browning were'
balloted for and duly elected members of the Club ; six pro-
posal forms were read for the first time.

Dr. Kendle said there had been some discussion about the
method of informing members of the subjects of forthcoming
papers ; he said that it was not always possible to announce
these beforehand, but that when they were known in time they
were announced in the English Mechanic, and notices were also
displayed in the windows of some of the principal opticians.

The Secretary announced that the next Ordinary Meeting
would be on June 11th, and that there would be a Gossip Meeting
on May 28th, and an excursion to Hanw^ell and Greenford on
May 25th.

The President then called upon Mr. F. Martin Duncan to
deliver his address on " Insects as Transmitting Agents in
Disease."

Mr. Martin Duncan said that this branch of entomology was
a comparatively recent study. He dealt very briefly with the
housefly as a disease-carrier, and stated that the blowfly, although
occasionally a carrier, is not so dangerous. The flesh fly, easily
distinguished by its striking markings, has been causing trouble
on the Western Front by laying its eggs in wounds. This fly is
very persistent in attacking meat, and will drop its larvae through
the gauze covers which are sometimes used as a protection. The
liting flies are more important. Anthrax has been communicated
to man through the bite of a tabanid fly whose mouth- parts were
contaminated by its having bitten an infected animal. In Africa,
Trypanosoma gambiense (the protozoon which causes sleeping
sickness) is carried from infected persons to others by the biting
tsetse flies, Glossina ■palpalis and G. morsitans. These flies frequent

442 PROCEEDINGS OF THE

sliady places close to fords, or drinking or washing places, and
after biting return to their resting-places until another oppor-
tunity occurs. Some trypanosomes, which do not appear to harm
their usual hosts, when transferred to other animals cause disease,
and possibly death. The tsetse flies are larvi parous, the larvae
being nourished in the body of the female, and pupating soon
after they are discharged. The disease called Ngana, which
affects horses and cattle, is transmitted by G. longifeymis. The
opening up of the African trade routes is largely responsible for
the spreading of sleeping sickness. The early settlers often lost
most of their oxen in passing through " fly-belts," and " salted "
animals — i.e. those which had had the disease mildly, and were
consequently immune — were much sought after. They used to
wait for dull weather or dark nights, when the flies were not so
active, to pass through the infested districts.

The speaker then dealt with mosquitoes, and described the
ravages of yellow fever and malaria in South America and Panama.
The French failure to cut the Panama Canal was owing to these
diseases, and it was due to the researches of Manson, Ross, Bruce,
Grassi and others that the responsibility of communicating these
diseases has been traced to mosquitoes. Means having been
adopted to destroy these insects, not only has it been possible
to cut the Panama Canal without serious loss of life, but Santos
and Rio, where formerly yellow fever was rampant, have prac-
tically become health resorts. Mr. Martin Duncan recounted
some of his experiences in " oiling " the ponds in these districts —
i.e. covering the surface of the water with a film of mineral oil
that the air-breathing larvae are unable to penetrate with their
breathing siphons, and are consequently drowned. Malaria or
ague used to be common in the English fen districts, but now
most of the swamps have been drained : and, the mosquitoes'
breeding places having been destroyed, the disease has almost
died out. Some strange " cures " for ague were described, and
a short account given of the life-history of the anopheline
mosquitoes and the malaria blood- parasite.

The human flea may transmit Kala Azar, and rat-fleas are the
carriers of plague. There are two ways by which inoculation
may possibly be effected. Faecal matter containing plague
bacilli is frequently discharged while the flea is sucking blood,
and this infected material may be rubbed into the wound by the

QUEKETT MICROSCOPICAL CLUB. 443

irritated victim. Sometimes the alimentary canal of the flea
becomes completely blocked by a mass of Bacillus pestis, and
then, when the flea tries to suck, a churning action takes place,
and some of the bacilli are regurgitated, and pass into the wound.

Typhus fever and " trench fever " are diseases that are trans-
mitted by lice. It was typhus from which the Serbian Army
suffered so severely. These diseases are probably transmitted
by inoculation from the excreta. The bed-bug is a possible carrier
of typhus, and an Indian bed-bug is responsible for spreading the
disease known as Oriental sore.

The so-called harvest-mite, by burrowing under the skin,
causes, in some cases, such intense irritation that a certain amount
of fever results. Ticks convey various diseases of both man and
animals from infected to healthy subjects. When a tick is tuU-
fed it falls to the ground from the animal on which it has been
feeding, and rests until it requires another meal, when it climbs
on to another animal and feeds again. If the first animal should
be diseased the second may possibly become infected.

The President emphasised the importance of studying the
habits of a disease-carrying insect before fighting it.

The Secretary read the following note from Colonel Clibborn,
who w^as unavoidably absent from the meeting :

That immunity to the results of malarial infection may be
acquired naturally appears to be demonstrated in the case of the
Tarus — inhabitants of the Tarai tract in North- West India.

The Tarai is a belt of clay soil deposited as the result of the
denudation of the mountain slopes. It has a high spring level ,
is covered in large part by forests, stretches of high grass and
swamps. It is flooded in many places during the wet season,
and, as may be imagined, has an abundant and varied supply
of animal, plant and insect life. It is the paradise of the sportsman
and a fruitful field for the naturalist, who can, however, only
visit it with a due regard to health during the cold weather, or
for short periods in the early part of the hot season. The climate
is considered deadly in the latter part of the rains and while the
flooded areas are drying up.

The Tarus are indigenous inhabitants of the Tarai — live in
their villages there all the year round, and do not suffer to any
marked extent from ill effects due to the climate. They are
great sportsmen — eat fish, meat whenever they can get it,

444 PROCEEDINGS OF THE

particularly wild pig — and indulge frequently in native liquor.
They assert this is necessary as a protection from the effects of
the climate. They cultivate the land close to their villages, and,
on the whole, pass happy, contented lives. The Taru children
appear to enjoy as good health as their parents.

The soil of the Tarai is productive and rent inconsider-
able; there are, therefore, many inducements to cultivators
from the densely populated tracts at a distance from the hills
to emigrate to the Tarai and occupy portions of the untenanted
lands. This goes on intermittently, and, as well as I can re-
member, the loss of life is between 70 to 80 per cent. In any
case it is very large indeed. The Government officials who ad-
ministrate the Tarai cannot reside there throughout the year
without certain loss of health, if not worse. Even during the
cold weather it is necessary to take quinine and live carefully.
It has been found that very minute daily doses of quinine
taken for some weeks before entering the mahirious tracts, and
continued throughout the stay there, is practically a complete
protection against the results of infection. In one instance, out
of a party of about one hundred persons — European and native —
who passed some six months in the Tarai, only one man was
affected, and this was the one man of the party who had not
been given the preliminary treatment.

These latter points are somewhat wide of the question of
naturally acquired immunity, but may be interesting with refer-
ence to malarial infection generally.

Mr. C. D. Soar stated that the "harvest-mites" were the
larvae of a so far undetermined species, probably a Trornhidium,
and that it was quite possible that they belonged to more than
one species.

In reply to a question by the President concerning the occur-
rence of large numbers of fleas in deserted houses, where they
could not obtain their natural food, Mr, Martin Duncan said that
fleas that had never tasted blood seemed to be able to live a much
longer time than those which had.

A hearty vote of thanks was accorded to Mr. Martin Duncan
for his address.

At the 535th Ordinary Meeting of the Club, held on June llth,
1918, the President, Dr. A. B. Ilendle, M.A., F.R.S., F.L.S., in

QUEKETT MICROSCOPICAL CLUB. 445

the chair, the minutes of the meeting held on May 14th were
read and confirmed.

Messrs. Ashley E. Oram, John A. Manning, Geo. Eichard
Titchener, H. F. Green, F. Adolphus Brokenshire, Chas. J.
Lock and Wm. Geo. Collins were balloted for and duly elected
members of the Club.

The Secretary read a note by Mr. E. M. Nelson on " Pond
Life," dealing with the particles 0*65 to 1*4 /u, in diameter present
in the cells of the confervoid algae which are old and about to
decay. If these particles, which are in Brownian movement, are
examined with crossed Nicols, those in the smaller filaments
become brilliant, while those in the larger filaments, which are
smaller, remain dark. This also can be seen with a 1/6 in. If
a water imm. 1/12 in. be used the particles are seen to have the
power of becoming invisible and again reappearing ; they also
grow, becoming double, like a diplococcus, and then passing on
to the tetraspore stage, but they have not been seen to divide
into separate spores. Mr. Nelson suggests that the movement
is a combination of pedesis and flagellate movement.

The President then gave an address on " Some Points in the
Structure and Growth of Grasses." Dr. Kendle said grasses, as
generally understood, are herbs with slender stems and narrow,
ribbon-like leaves. They form one of the largest and most wide-
spread families of flowering plants, adapted to very different
conditions of soil and climate, but with a remarkably uniform
plan of structure. In the aggregation of many individuals of
one or a few species, either growing alone or scattered through a
mixed herbage, covering large areas, the family forms a pre-
eminent type of the earth's vegetation, as e.g. in meadows and
pastures, steppes and prairies. These sociable grasses keep the
soil warm and moist, and protect other plants during cold or
dry seasons, and their roots aiid creeping stems help to break
up the soil. Dr. Rendle then showed on the screen photographs
of various types of grass vegetation, viz. calcareous limestone
and chalk downs, with a short pasture largely composed of sheep's
fescue, probably of great age, and likely to continue treeless on
account of the thin layer of soil and poor supply of underground
water; swamps, in which the broad-leaved reed flourishes;
mud flats at Southampton Water, Poole Harbour, and other
places, where thousands of acres have been taken over by Sfartina

446 PROCEEDINGS OF THE

Toivtisendi, whose long spreading roots and stolons bind the soil
together, while the thick stems and leaves collect flotsam, and
so, in time, reclaim the land; sand dunes, on \vhich marram
grass grows, and by sending out its long roots and runners may
so consolidate the sand that other plants are able to grow there.
This grass, even if it becomes covered up by the drifting sand,
will grow right up through it. Agropyron juncewn, though not
so common, will stand the sea spray even better. The woody,
tree-like bamboos are common in Asiatic jungles, and there is
often a. bamboo zone on the m^ountains of tropical Africa and
the Andes.

The leaves of grasses are arranged in two alternate rows.
Shoots are produced, as usually, in the axils of the leaves. Barren
shoots never occur on annual grasses. The shoots may grow up
within the leaf-sheath (intravaginal) or they may break through
and spread laterally from the base (extravaginal). The first
method of growth gives rise to isolated tussocks characteristic
of a warm climate (steppes and savannahs), the second method
produces turf and sods such as we find in a cool or temperate
climate.

The grass stem, or " culm," grows not only at the tip, but at
the bases of the internodes, where the soft, growing tissues are
supported by the leaf-sheaths. The " nodes " are thickenings of
the leaf-sheaths, and their function is to raise the culm to an
erect position if it should become bent. They consist of thin-
walled, strongly turgescent tissue, which is sensitive to the force
of gravity. When the culm is horizontal or oblique the cells of
the node on the side turned towards the earth begin to lengthen ;
the lower side thus becomes longer, while the upper side is short-
ened from pressure on the opposite side. Several nodes may
share in this process, which goes on until the upper internodes
have resumed the vertical. The typical grass stem is hollow,
and rigidity is given to it by bands of thick-walled tissue. This
structure is adapted for the production of a tough, flexible stem
with a minimum expenditure of material. This stem has to last
long enough to raise the leaves and i florescence into the air
and be flexible enough to allow swayi.ig in the wind witliout
breaking, which changes the air round the leaves, and thus assists
in the process of feeding, and also in the distribution of the pollen,
and later of the fruits. This economical manner of growth is

QUEKETT MICROSCOPICAL CLUB. 447

one of the reasons for the success of the family. The leaf con-
sists of a Siieath, a ligule, which is a prolongation of the sheath^
and helps to prevent water from running down between the
sheath and the stem, and a blade. The function of the blade is
to carry on the interchange of gases between the plant and the
air, from which the plant obtains raw carbonaceous food-stufit,
and to give off in the form of vapour the surplus water which has
served as a carrier for the raw nitrogenous food-stuff absorbed by
the roots and sent up to the leaves. When plants live in dry places
or are exposed to dry winds there is a danger of excessive evap-
oration and consequent withering of the leaves. This is guarded
against in various ways. In Echmocactus, for instance, the
whole structure is altered for this purpose. The leaves disappear,
the branches become spines, and the plant becomes a green
wax-coated water- reservoir. The grass-leaf effects this without
any expensive modification of form or structure by simply rolling
up its leaf-surface. Hence the character of the blade often
reflects that of the environment, being thin and flat in shade
grasses, and narrow, or often rolled, in those exposed to sun,
wind or drought. The rolling up is often caused by special
motor cells. Some of the cells of the upper epidermis, either
next the central rib or betvv^een the other ribs, are large and
thin-walled and full of sap when distended. These cells are so
placed that as they lose water by evaporation they contract and
draw together the halves of the blade, or each ribbed longitudinal
segment, thus causing infolding or inrolling and protection of the
stomata on the concave surface of the leaf. These stomata are
often situated in crevices running up the length of the leaf, and
the opening of the crevice may be protected further by hairs
which interlock when the leaf rolls up. The outer side of the
leaf, which is left exposed, is protected by harder tissues. The
President promised to deal v/ith the flowers of grasses on a sub-
sequent occasion, and he was heartily thanked for his interesting
address.

There will be an excursion to the grounds of Sion House on
the 22nd inst. At the next Ordinary Meeting, which will be on
October 8th, the first meeting of the new session, Mr. N. E.
Brown, A.L.S., will give an address on " The Fertilisation of th&
Fig."

449

INDEX.

.'Adapter for Wenham bin-
ocular
,-Adineta cuneata sp. nov.
-African species of Volvox,
Two . . . .

Ahrens, CD. E. M. Nelson

F. J. Cheshire .

■ Ainslie, M. A. Nitzschia sin-
galensis : a note on Mr.
Merlin's paper
The measurement of mag-
nifying power
Akehurst, S. C. A tank and
weed-holder for pond-
life work .
^alacris, Habrotrocha .
. Aleurodes, Dr. Sharp on

Insect-enemies of .

Aleurodes asparagi

hrassicae

citri

— proletella
A^nphipleura pellucidu
Anacampseros ruhens. Seeds

of. N. E. Brown
Anatomy of House-fly
' animosa, Mniohia
. Annual Report for 1915

1916

1917

. Anopheles, Larva of .
Anthocyanin

B

. Baker, Henry. On Rotifera

Baker, W. E. Watson. A

series of micro-slides .

.Bale, W. M. Note on the
measurement of magni-
fying powers

iSarnard, J. E. X-ray Re-
search into organic
structure as exemplified
■33y the.Eoraminifera ,

PAGE

396
179

425

381
383

113

315

291

162

10

13

7

11

12, 13

11

111, 114

290
341
178
99
298
399
395
343

205

96

307

195

Bdelloid and other Rotifera.
Collection of D. Bryce .

— Rotifera of South Africa.

W. Milne . . 47

Bdelloida, Examination of .

— Habitats of .
Beale Reflector, How to make

a . . . .

Binocular Microscope, The.

E. M. Nelson
— ■ — Swift's portable

A prism for eye-piece

Brown, N. E. On the seeds

of Anacampseros ruhens

— Evolution as illustrated

by a genus of plants
" Brownian " movement in

algae. E. M. Nelson .
Bryce, D. Notes on the

collection of Bdelloid

and other Rotifera
Burton, J. Euglena viridis

in an encysted state

— On a species of Aleurodes

— On the larva of Ano-

pheles

C

Calcareous Sponges, Spicules
of ... .

carnosus, Didymodactylos .

Census of desmids (Dart-
moor)

Cheshire, F. J. C. D. Ahrens

" Chessman " spicule and
the vibratory theory,
The. . . . 241

in the genus Latrun-

culia. A. Dendy . 231

childi, Philodina . . 65

Chlorophyll . . . 342

Clibborn, J. Immunity to

malarial infection . 443

Collecting net for Rotifera . 207

PACK

205

, 149
224
223

308

429

89
89

290

345

445

205

345

7

395

36

56

265

383

450

INDEX.

438
278
247

27

90

PAGE

Colloscleres, gelatinous spi-
cules . . . .290
Collosclerophora . .290
Colour in plants and its pre-
servation. A. B, Rendle 342
Conv^ersion of English and
metrical measure, Taljle
for . . . . 406
Cook, J. T. A simple trough

for pond-life . . 85

cuneata, Adineta . .179

cuthhcrtl, Macrotrachela . 79
Cystoliths . . . 358

D

Dark-ground illuminator,
oil-immersion. E. M.
Nelson

Dartia Harrisi sp, nov.

Dartmoor, Dosmid flora of .

Dendy, A. Some factors of
evolution in sponges .

— The study of sponges .

— On the spicular structure

of Oeodia japonica
■ — Tiie Chessman spicule of
the genus Latrimculia ;
a study in the origin of
specific characters

— Gelatinous sponge spicules
Dercitopsis minor

Desmid areas, Relative rich-
ness of . . •

• — flora of Dartmoor. G. T.
Harris

Dcsmids, Mounting .

— Preservative for .
Didymodactylos carnosus

sp. nov.
Discodermia, The spicule of
Discorhaljds of LatnjncuUa
Disease, Transmitting agents

in .
Drimys, The wood of .
Duncan, F. M. Insects as

transmitting agents in

disease

19

E

elusa, Habrotrocha
Euglcna viridis. Encysted

state of. J. Burton
Evolution, divergent and

progrcrisivo
— illustrated by a genus of

plants. N. E. Brown .

J J

231

289
91

254

247
21

18

b*6
31

9 •. ( ,

441
357

441

i'J2

345

45

345

Eye-pieces, Microscope
Eylais Wilsoni sp. nov.

F

falcatus, Monoceros

False- scorpions, s.v. Pseudo-
scorpions.

faveolafa, Macrotrachela

Flask-cells of Schistostega .

Flightless birds. Evolution
of ... •

Foraminifera, Radiographs
of. E. Heron-Allen .

Fiimago vagans. The sooty
fungus

G

galeata, Scepanotrocha
Gelatinous sponge-spicules,

A. Dendy .
Gemmae of Schistostega .
Genetic affinity, Indices of .
Geodia japonica, Spicular
structure of. A. Dendy
Gnat (Culex), Life- history of.

J. R. Leeson
Gnetaceae, The* wood of
grandis, Philodina
Grasses, The structure and

growth of. A. B. Rendle
Grundy, J. On polarising

appai'atus .

— On polarised light .
gulosa, Habrotrocha .

H

Habrotrocha alacris sp. nov.

— elusa si^. nov.

— elusa var. vegeta

— gxdosa sp. nov.

— iners sp. nov.

— pertinax sp. nov. .

— plncida sp. nov.

— plana sp. nov.

— tranquilla sp. nov. .

— valida sp. nov.

Harris, G. T. The collec-
tion and preservation
of dcsmids .

— The desmid flora of

Dartmoor .

— On Schistostega osmun-
dacea Mohr. .

Harrisi, Dartia .
Henoceros lalcatus sp. nov. .
llenocerotidae fam. nov. .

PAGBt

437

281

4»

155
369

29

19^

12-

178

289-

3()(>-
43

19S

38»
35(>'

6a

445

389^
392
169

16i

162

166

169

158^

108.

1 56

157

167

160

15-

247

361
278.
140
149-

INDEX.

451

Heron- Allen, E. Radiographs
of Foraniiiiifera .

Hilton, A. E. On the for-
niiition of Sporangia in
the genus Stemonitis .

— On sporangial characters
of .Mycetozoa and factors
which influence them .

— A specimen of Trichia

affinis
~' Honey- dew " in Aleurodes
House-fly and its danger to

health. J. R. Leeson .

— Anatomy of. J. R. Leeson
Hydracarina, Two new

species of. C. D. Soar.

Icerya purchasi .

Illumination for difficult reso-
lutions

iners, Habrotrocha

inopinata, Philodina .

Insects as transmitting
agents. F. M. Dimcan

Insects' eggs. J. M. Offord

J ones. Chapman. The secon-
daries or dotted struc-
ture of Pinnulariae

K

Kew, H. WalUs. An his-
torical account of the
Pseudoscorpion-f a u n a
of the British Islands .

PAGK

195

-.Latrmiculia, The spicules of
the genus. A. Dendy .
Latrunculia apicalis .

— bocagei
Lebertia sefvei .

-Leeson, J. R. On the House-
fly, Musca domestica,
with special reference to
danger to health

— The anatomy of the House-

fly ... .

— The life history of the

Gnat (Culex)
Leucosolenia, Structure of .
Light-cells of Schistostega .

137

337
9

339
341

277

93

115

158
69

441
391

107

117

231
233
232
375

339

341

388

32

370

TAGE

M

macmillani, Macrotrachela . 80
Macrotrachela cuthberti sp.

nov. .... 79

— faveolata . . .155

— quadricornifera var. rigida 180

— macmillani sp. nov. . 80

— petular.s s,]i. now . . 77'

— smtVAt sp. nov. . . 151

— timida sp. nov. . .152

— timida var. inquies . 154

— verecunda sp. nov. . .149
Magnifying power, Measure-
ment of. E. M. Nelson 379

Fonmilafor . .319

Magnifying powers, Measure-
ment of. W. M. Bale . 307

M. A. Ainshe . .315

Malarial infection, Immunity

to . . . .443

Malaria, Mosquitoes and . 394
Merlin, A. A. C. E. On Nitz-
schia singalensis as a
test-object for the
highest powers . .111

Mesembryanthemmn, The

genus . . .346

Metrical measure, Table for 406
Microscope, The binocular . 429

— eye-pieces. E. M. Nelson 437
Microscopical characters in

systematic botany. A. B.

Rendle . . . 353

Micro-slides, A series of.

W. E. Watson Baker . 96
Milne, W. On the Bdelloid

Rotiferaot South Africa,

Pt. 1 . . .47

— On the Bdelloid Rotifera

of South Africa, Pt. II. 149
Mniobia animosa sp. nov. . 178
" Monmouthiana integral,"

The . . . .412

Monoceros falcatus sp. nov. . 49
Monocerotidae fam. nov. . 49
monteti, Otostephatios . 174

Mosquitoes and Malaria, J.

M. Offord . . .394

Moss-dweUing Rotifera . 215
Moss, Treatment of, for

Rotifera . . .217

Murray, James, Collecting

Rotifera . . .212

Mutations and variations . 29
Mycetozoa, Sporangial char-
acters of. A. E. Hilton 137

452

INDEX.

PAGE

N

Navicula and Cymbella, In-
termediate forms in the
genera. N. Yermoloff .

Nelson, E. M. On the
measurement of magni-
fying power

— C. D. Ahrens

— The binocular microscope

— Microscope eye- pieces .

— Oil-immersion dark-ground

illuminator

— "Brownian" movement in

decaying algae .

Nicol prism as an aid to
resolution .

nitida, Philodina

Nitzschia singalensis as a test-
object. A. A. C. E.
Merlin

Noll on Schistostega .

Notices of Books : Andrew
L. Winton. The Micro-
scopy of Vegetable
Foods

— George West. The Practi-

cal Principles of Plain
Photomicrography

— C. G. Moor. Aids to

Bacteriology

— W. Mansfield. Histology

of Medicinal Plants

— G. S. West. Cambridge

Botanical Handbooks :
Algae. Vol. I. .

— D'Arcy W. Thompson.

On Growth and Form .
Nuclei, Arrangement of, in
Plasmodium

407

379
381
429
437

438

445

115

67

111
371

185

186

187
283

284

333

5

Organic structure. X-ray re^-

search into .
Origin of specific characters
Otostephanos monteti sp. nov.

— regalis sp. nov.

— torquatus var. amoenus .

. 350

. 190

94

198,203

198, 201

87

O

Obituary Notices :

Braithwaite, R.

Curties, C. Lees

Dunstall, G. K.

Enock, Frederic

Lewis, R. T. .

Minchin, E. A.

Smith, Alpheus

White, Dr. Charters
Oflord, J. M., On Insects'
Eggs . . • •

— On Mosquitoes and Malaria 394
Oil-immersion illuminator

for dark- ground . .438

Optics, Teclmical . .329

341,

351

298

391

page:

195:

231
174
171
173^

patula, Philodina
Perichaetium of Schistostega
pertinax, Hahrotrocha .
petulans, Macrotrachela
Philodina acuticornia var.
odiosa

— childi sp. nov.

— grandis sp. nov.

— inopinata sp, nov. .

— nitida sp, nov.

— nitida var. decens ,

— patula sp, nov.

— praelonga sp. nov, .

— proterva sp. nov. ,

— rapida sp. nov.

— scabra sp. nov.
Photomicrographs as records.

G. H. Rodman .
Pinnvilariae, Secondaries of.
Chapman Jones .

— H. J. Slack on
Pinnularia nobilis

— viridis . . • •
placida, Hahrotrocha .
plana, Hahrotrocha . -
Plasmodium of Stemonitis .
Pleodorina illinoisensis
Pleurcta reticulata sp. nov. .
Polarised light. J. Grundy
Polarising apparatus. J.

Grundy

Pond collecting. Apparatus
for . . • •

Pond-life, A tank and weed-
holder for ,

— trough for, J. T. Cook.
praelonga, Philodina ,
President's Address, 1916.

A. Dendy .

1917. A. Dendy

1918. A. B. Rendle .

Prism for eye-piece of bino-
culars

Proceedings. Oct. 1915 —
Feb. 1916 ,

— Mar. 1 9 1 6— J une 1916 ,

— Oct. 191G— Feb. 1917 .

72
366-
168-

77'

71

65

60

69^

67

69

72

58

75

74

76-

385-

107
107
109
109
156
157
2
291
176
392

389

199

291

. 85

" [68

27
231
353

89-'

87
188-

287

\

INDEX.

45a

Proceedings. Mar. 1917 —
June 1917 .

— Oct. 1917— Mar. 1918 .

— April 1918— June 1918 .
protcrva, Philodina .
Protonema of Schistostega .
Protorhabd, The
Pseudoscorpion - fauna of

British Isles, Historical
account of. H. W. Kew

Q

Quekett, Dr., medallion por-
trait of . . .

R

rapida, Philodina

Rendle, A. B. Colour in
plants and its preserva-
tion ....

— The use of microscopical

characters in the sys-
tematic study of the
higher plants

— Some points in the struc-

ture and growth of grasses

regalis, Otostephanos .

reticulata, Pleureta

Rodman, G. H. On photo-
micrographs as records

Rotifera, Bdelloid, of South
Africa , . 47^

— Collecting and mounting.

C. F. Rousselet .

— and desiccation
—Parasitic

Rousselet, C. F. Some further
notes on collecting and
mounting Rotifera

S

scahra, Philodina
Scepanotrocha galeata sp .

nov. .
Schistostega osmundacea

■ early history of .

flask- cells of

gemmae of

habitat of

light-cells of

Noll on Hght-cells of

perichaetiiim

protonema

Scourfield, D. J. A slide of

Pleodorina illinoisensis
Silicoblasts in Latrunculia .
Smithi, Macrotrachela

PAGE

336
385
439
75
367
235

117

292

74

342

353

445
171
176

385

149

321

220
214

321

76

178

361

361

369

366

362

370

371

366

367

291
238
151

S oar, C. D. Two new species
of Hydracarina or
Water-mites, Dartia.
Harrisi and Eylais Wil-
soni . , . ,

— s.v. Williamson, W.
Spartina Townsendi .
Species, Definition of a
Specific characters, Origin of
Spicules, calcareous .

— gelatinous

— origin of

— siliceous

development of

Sponges, The study of. A

Dendy
Sponges (Porifera) :
Calcarea
Euceratosa .
Myxospongida
Tetraxonida .
Triaxonida
Sporangial characters of

Mycetozoa . ;

Stemonitis, Plasmodium of
— Sporangia of
Sterraster, or Geodia ball
Surface-tension, Demonstra-
tion of
Swift's portable (binocular)

microscope
Synthetic grouping of species
Systematics, On the value of

PAGE

277

445

410

231

90

289

91

91

235

90

90
91
91
91
91

137
2
3

194

337

89
40a
27,
420

Technical Optics . .329

Test- object for highest powers 111
Timber, Microscopic char-
acters of . . . 355
timida, Macrotrachela . 152
tranquilla, Hahrotrocha . 167
Traviss, W. R. A new adap-
tation of Swift's portable
microscope . . 89^

— An apparatus of use in

pond collecting . .199

— An adapter for use with

a Wenham binocular . 396

— A prism for use over the

eye-piece in binocular
microscopes . . 89

— Apparatus for demon-

strating surface-tension 337
Treasurer's Report for 1915 105

1916 . . .305

1917 . . . 405-

454

INDEX.

PAGE

Triceratium, Photomicro-
graphs of . . . 201
Trichia affinis . . . 337
Trichodragmata as mutations 39
Trough for pond-life . . 85

valida, Hahrotrocha . .160

verecunda, Macrotrachela . 149

Voigt (Dr.), Method of

collecting . . .211
Volvox, Two African species

of. G. S. West . . 425

Volvox africanus . .426

— Rousseletii . . . 426

W

Watch-glasses, solid . .323

Water-mites, s.v. Hydracarina.

Wenham binocular, adapter
for use with

West, G. S. A further con-
tribution to our know-
ledge of the two African
species of Volvox

Williamson, W., and Soar,
C. D. Lebertia sefvei .

Wilsoni, Eylais

X

X-ray research into organic
structure. J. E. Barnard

Y

Yermoloff,N. Notes on some
intermediate forms of
the genera Navicula and

PAGB

396

425

375
281

195

Cymbella

407

OPEICERS AND COMMITTEE.

{Elected February 1916.)

President :

Prof. Arthur Dendy, D.Sc, F.R.S.

Vice-Presidents:

C. F. RoussELET, Curator R.M.S.

Edmund J. Spitta, L.R.C.P., M.R.C.S., F.R.M.S., F.R.A.S.

D. J. ScouRFiELD, F.Z.S., F.R.M.S.

David Bryce.

cowiiviittee !

M. A. Ainslie, R.N., B.A., F.R.A.S.

E. E. Banham.

C. H. Bestow, F.R.M.S.

N. E. Brown, A.L.S.

G. H. Gabb.

Jas. Grundy, F.R.M.S.

A. Morley Jones.

J. M. Offord, F.R.M.S.

R. Paulson, F.L.S., F.R.M.S.

C. D. Soar, F.L.S., F.R.M.S.

Chas. S. Todd.

J. Wilson, F.R.M.S.

Hon. Treasurer :

Frederick J. Perks, 48, Grove Park, Denmark Hill, S.E.^
to whom subscriptions should be sent.

Hon. Secretary;

James Burton, 8, Somali Road, West Hampstead, N.W.,
to whom all correspondence should be addressed.

Hon. Sec. for Foreign Correspondence:

C. F. Rousselet, Curator R.M.S., Fir Island, Mill Hill, N.W.

Hon. Reporter :

R. T. Lewis, F.R.M.S,, 25, Craigerne Road, Blackheath, S.E.

Hon. Librarian :

S. C. Akehurst, F.R.M.S., 60, Bowes Road, Palmers Green, N.

Hon. Curator :

C. J, H. SiDWELL, F.R.M.S. 46, Ashbourne Grove, Dulwich, S.E.

Hon. Editor :

A. W. Sheppard, F.Z.S., F.R.M.S., 1, Vernon Chambers, W.C,
9

11

PAST PRESIDENTS.

Elected

July 1865.
1866.

jj

>>

jj

>j

>>

5)

J>

1867-8.

1869.

1870-1.

1872-3.

1874-5.

1876-7.

1878.

1879.

*EDWIN LANKESTER, M.D., F.R.S. .
♦ERNEST HART ....

♦ARTHUR E. DURHAM, F.R.C.S., F.L.S.
*PETER LE NEVE FOSTER, M.A. .
♦LIONEL S. BEALE, M.B., F.R.S.
ROBERT BRAITHWAITE, M.D., F.L.S.
♦JOHN IVIATTHEWS, M.D., F.R.M.S. .
♦HENRY LEE, F.L.S., F.G.S., F.R.M.S., F.Z.S
♦THOS. H. HUXLEY, LL.D., F.R.S. .
♦T. SPENCER COBBOLD, M.D., F.R.S

X .l^.o. ......

T. CHARTERS WHITE, M.R.C.S., L.D.S
F.R.M.S. .....

♦M. C. COOKE, M.A., LL.D., A.L.S. .
*W. B. CARPENTER, C.B., F.R.S.

A. D. MICHAEL, F.L.S., F.R.M.S. .

B. T. LOWNE, F.R.C.S., F.L.S. .
♦Rev. W. H. DALLINGER, LL.D., F.R.S

F.R.M.S. . . .
EDWARD MILLES NELSON, F.R.M.S.
♦J. G. WALLER, F.S.A.
JOHN TATHAM, M.A., M.D., F.R.M.S.
GEORGE MASSEE, F.L.S. . . Feb. 1900-1-2-3.

EDMUND J. SPITTA, L.R.C.P., M.R.C.S.,

F.R.A.S., F.R.M.S. . . . Feb. 1904-5-6-7.
♦E. A. MINCHIN, M.A., F.R.S. . Feb. 1908-11.

* Deceased.

j>

}>

j>

1880-1.
1882-3.

1884.
„ 1885-6-7.
Feb. 1888-9.

„ 1890-1-2.
1893-4-5.

1896-7.
1898-9.

J)

>j

>>

Ill

HONOEAEY MEMBERS.

-♦♦-

Date of Election.

Feb. 17, 1893. Robert Braithwaite, M.D., F.L.S., F.R.M.S.

(Past President)

26, Endymion Boad, Brixton Hill, S.W,

Feb. 17, 1893. T.Charters White, M.R.C.S.,L.D.S., F.R.M.S.

(Past President)
59, Victoria Road South, Southsea.

Mar. 19, 1897. B. T. Lowne, M.D., F.R.C.S., F.L.S. (Past

President)

34, Portland Boad, Hove, Sussex.

May 18, 1906. Dr. Eugene Penard

Rue Topffer 3, Geneva,

Jan. 23, 1912. Alpheus Smith

14, Leigham Vale, Streatham, S.W.

April 23, 1912. Fred Enock, F.L.S., F.R.M.S., F.E.S.

54, St. Mary's Terrace, West Hill,
Hastings.

IV

LIST OE MEMBERS.

-»4-

Date of Election.

Nov. 24, 1914. Adams, Walter

85a, Rushey Green, Catford, S.E.
Dec. 23, 1913. Ainslie, "Maurice Anderson, R.N., B.A.,

F.R.A.S.

8, Woodville Road, Blackheath, S.E.
Feb. 16, 1906. Akehurst, Sydney Charles, F.R.M.S. {Hon.

Librarian)

60, Bowes Road, Palmer's Green, N.
April 25, 1916. Aldis, Arthur WiUiam

44, Earls Court Square, S.W.
Feb. 19, 1904. Allardice, Lieut. WiUiam McDiarmid

St. Endellion, Port Isaac, R.S.O. Cornwall.
May 24, 1910. Allen, Wilham Nassau

*' Caerneagh," North Circular Road,
Dublin.
Jan. 28, 1913. Allison, Arthur Morris

8, Sidney Road, Beckenham.
Jan. 26, 1915. Andrew, Jas. Grant

62, Grovelands Road, Palmer's Green, N.
Dec. 15, 1899. Angus, H. F., F.R.M.S.

83, Wigmore Street, Cavendish Square, W.
Feb. 25, 1913. Armitage, John Joseph, L.D.S.E.

5, Cavendish Place, W.
June 21, 1907. Arpin, John Edward

131, Castelnau, Barnes, S.W.
Feb. 22, 1889. Ashe, A., F.R.M.S.

55, Warrior Square, Southend-on-Sea.
Feb. 28, 1911. Austin, Henry

Tudor House, 120, Greenwich Road,
Greenwich, S.E.

Date of Election.

June 4, 1909. Baddeley, William H. L.

29, Church Crescent, Church End, Finch-
ley, N.
April 17, 1903. Bagshaw, Walter, J.P., F.R.M.S.

" Moor field," Birkenshaw, near Bradford,
Yorks.
Sept. 26, 1884. Baker, F. W. Watson, F.R.M.S.

313, High Holborn, W.C,
Mar. 16, 1906. Baker, Henry James

13, Moorgate Street, B.C.
April 2, 1909. Baker, Wilfred E. W^atson

313, High Holborn, W.C.
Nov. 25, 1913. Bale, Wm. Urontier, F.R.M.S.

63, Walpole Street, Kew, Victoria, Australia.
June 19, 1908. Banham, Edward Elliott

64, Queen's Avenue, Church End, Finch-
ley, N.
May 28, 1912. Barnard, Edward Jas.

10, Denver Road, Stamford Hill, N.
Feb. 25, 1913. Barnard, Joseph Edwin, F.R.M.S.

Park View, Brondesbury Park, N.W,
Mar. 19, 1886. Barnes, W.

23, Jackson Road, Holloway, N.
May 28, 1912. Barratt, Kenneth Franklin

''Bell Moor,'' Hampstead Heath, N.W.
May 28, 1912. Barratt, Thos. Franklin

''Bell Moor," Hampstead Heath, N.W.
Sept. 27, 1872. Bartlett, Edward, L.D.S., M.R.C.S.E.

38, Connaught Square, W.
Nov. 26, 1912. Bassett, Ernest Henry

" Pro tem," Amberley Road, Palmer's
Green, N.
June 17, 1892. Bates, C.

1, Windsor Road, Denmark Hill, S.E.
Oct. 18, 1895. Baugh, J. H. A.

63, Cambridge Road, Hammersmith, W,
June 4, 1909. Baxendale, Frederick G.

Corbally, Arbrookhane, Esher.
Jan. 16, 1891. Baxter, W. E., F.R.M.S.

170, Church Street, Stoke Newington, N,

VI

Date of Election.

Oct. 27, 1914. Beattie, Wm.

8, Lower Grosvenor Place, S.W.
Nov. 26, 1875. Beaulah, John

Albert House, Brigg.
July 25, 1884. Beck, C, F.R.M.S.

68, Cornhill, E.G.
June 27, 1911. Bennett, Lionel C.

49, Erpingliam Road, Putney, S.W .
Feb. 16, 1906. Bestow, Charles H., F.R.M.S.

43, Upper Clapton Road, N.E.
Mar. 28, 1916. Bevington, Regmald, H. S.

28, Gannon Street, E.G.
Oct. 26, 1915. Bilham, Ernest Q.

Town Hall, Bethnal Green, E.
June 16, 1905. Blair, William Nisbet

23, West Hill, Highgate, N.
Oct. 2, 1908. Blockley, Edgar A.

27, Beechwood Avenue, Kew Gardens.
May 19, 1899. Blood, Maurice, M.A., F.C.S., F.R.M.S.

51, Winchester Avenue, Brondesbury,
N.W.
Feb. 22, 1916. Bocock, Chas. Hanslope

The Elms, Ashley, Newmarket.
Jan. 25, 1915. Boltz, Arthur

21, Ashbridge Road, Leytonstone.
Feb. 25, 1913. Booker, Alfred James

37, Glaremont Road, Highgate, N.
April 25, 1911. Bowtell, Alexander Jas.

123, Dalston Lane, N.E.
Nov. 23, 1915. Bradbury, John Geo.

1, Hogarth Hill, Finchley Road, Hendon,
N.W.
Nov. 15, 1907. Bradford, William Barnes

65, Tyrwhitt Road, St. John's, S.E.
Mar. 24, 1914. Brand, Felix R. W.

37, Hatton Garden, E.G.
Nov. 17, 1905. Bremner, John Unthank

277, Kin^ Street, Hammersmith, W.
Jan. 24, 1911. Bridge, Samuel

28, Larkhall Rise, Glapham, S.W.

vu

Date of Election.

Nov. 6, 1908. Broad, John Moxon

2, Nicoll Road, Harlesden, N.W,
Nov. 24, 1914. Brokenshire, Frederick Reardon

7, Hillshoro' Avenue, Pennsylvania,
Exeter.

Feb. 23, 1915. Brooke, Chas. Hy. Alfred

159, Sntherlaiid Avenue, W.
May 28, 1912. Brooke, Thos. Robinson

12, Warren Road, Chingford, N.E.
Dec. 4, 1908. Brooks, Theodore, F.R.M.S.

British Vice-Consul, Guantanamo, Cuba.
Dec. 19, 1890. Brough, J. R.

" Eversley," Shepherd's Hill,Highgate,N,
Mar. 15, 1907. Browett, William

" Beaumont," Pear field Road, Forest
Hill, S.E.
May 24, 1910. Brown, Edward George

8, Freke Road, Battersea, 8.W,
Jan. 18, 1907. Brown, Nicholas Edward, A.L.S.

6, The Avenue, Kew.
Jan. 28, 1887. Browne, E. T., M.A., F.R.M.S.

Angle field, Berkhamsted, Herts.
Mar. 18, 1904. Brushfield, N. W.

13, Allfarthing Lane, Wandsworth Com-
mon, S.W.

Jan. 15, 1892. Bryce, David (Vice-President)

37, Brooke Road, Stoke Newington, N.
May 28, 1912. Bull, Albert Edwd.

3, Canterbury Terrace, Sudbury, Harrow,
May 15, 1908. Bunting, Percival J.

" Lynhurst," Birches Barn Road, Wol-
verhampton.
Jan. 20, 1905. Burnell, Charles Edward

29, High Street, Shepton Mallet.
Feb. 28, 1913. Burns, Dr. Nesbitt, M.B., B.A., F.R.S.E,

" The Lodge," Highbridge, Somerset,
April 20, 1906. Burrell, T. Leonard

20, Upper Hornsey Rise, Islington, N.
April 28, 1914. Burton-Brown, Gerald Burton, M.D.

Harston, Sidmouth.

Vlll
Date of Election.

Feb. 19, 1904. Burton, James {Hon. Sec),

8, Somali Road, West Hampstead,
N.W.
May 26, 1914. Buttemer, Robt. Wm., F.C.S., M.LA.E.

St. Mary's, Godalming.
Feb. 19, 1904. Butterworth, Arthur Cyrus, F.R.M.S.

Granville, Crowstone Road, Westcliff-on-
Sea.

April 15, 1904. Caffjni, Charles Henry

32, Falkland Road, Hornsey, N.
June 18, 1897. Campbell, Colney

47, Selborne Road, Southgate, N.
Mar. 16, 1906. Capell, Bruce John, F.R.M.S.

10, Castelnau, Barnes, S.W,
Mar. 28, 1914. CarHle, E.

28, Chatsworth Road, Croydon.
Jan. 20, 1905. Carrington, John

P.O. Box 48, East London, South
Africa,
May 24, 1910. Carruthers, Ferdinand Gilbert

10, Addison Road, Bedford Park, W.
Jan. 25, 1910. Carter, John Arthur

6, Temple Road, Stowmarket.
June 17, 1892. Chaloner, G., F.C.S.

South Street, Colyton, S.O., Devon,
June 28, 1910. Charlton, Alfred Edward

13, Parkhurst Road, Camden Road,
N.
Oct. 26, 1909. Cheavin, Harold Squire, F.R.M.S.

70, Somerset Road, Huddersfield.
April 22, 1913. Cheshire, Frederic John, F.R.M.S.

23, Carson Road, Dulwich, S.E.
Mar. 22, 1878. Chester, The Very Rev. the Dean of

The Deanery, Chester.
Dec. 18, 1896. Chipps, F. W.

201, Castelnau, Barnes, S.W.
Jan. 20, 1905. Christie, John, F.R.M.S.

Henleigh, Kingston Hill, Surrey.

\

Date of Election.

Mar. 17, 1905. Clemence, Walter

14, Beckenham Grove, Shortlands.
Jan. 27, 1914. Clibborn, Lt.-Col. John

87, Victoria Street, S. W,
Oct. 18, 1907. Coldwells, William Henry

Eedcote, Shirley Road, Wallington.
Oct. 21, 1904. Conrady, Alexander Eugen, F.R.A.S.

23, Flanchford Road, Stamford Brook,
W,
Mar. 25, 1913. Cook, John Thomas

216, Olive Road, West Dulwich, S.E.
April 28, 1914. Cooley-Martin, Francis

" Hillside'^ Portsdown, Cosham, Hants.
Nov. 26, 1912. Coon, Joseph May

" Morwenna,'' St. Austell,
Jan. 18, 1901. Cox, Thomas N.

104, Treslsillian Road, Brockley, S.E.
Jan. 15, 1904. Cox, William

" The Pound," Ling field, Surrey.
June 19, 1903. Coxhead, G. W.

36, Linthorpe Road, Stamford Hill, N.
Jan. 25, 1910. Crabtree, James Fox, B.A.

40, Brazennose Street, Manchester.
April 27, 1915. Craig, Rev. S. Runsie

" Craigmount," Central Hill, Upper
Norwood, S.E.
Nov. 25, 1913. Creese, Edward J. E., F.Z.S., F.R.M.S.

29, Cornford Grove, Balham, S.W,
Nov. 21, 1902. Cressey, Dr. G. H.

Oak Manor, Tonhridge.
Aug. 28, 1868. Crisp, Sir Frank, LL.B., V.P.L.S., B.A.,

F.R.M.S., F.G.S., F.Z.S.

5, Lansdowne Road, Notting Hill, W,
Nov. 16, 1906. Crosbie, Walter

Kenilworth, Lyonsdown Avenue, New
Bar net.
Feb. 16, 1900. Crossland, R. E., A.R.I.B.A.

10, Serjeant's Inn, Fleet Street, E.O.
Mar, 16, 1894. Culshaw, Rev. George H., M.A.

The Rectory, Iver Heath, Bucks,

Date of Election.

Jan. 16, 1903. Curties, C. Lees, jun.

244, High Holhorn, W.G.
May 18, 1906. Cuzner, Edgar, F.R.M.S.

36, Trothy Road, Bermondsey, S,E.
Nov. 18, 1904. Dade, Willoughby Dreyer

13, Glendinning Avenue,- Weymouth.
Jan. 17, 1908. Dallas, Charles Caldwell, F.R.G.S., F.Z.S.

Eastley Wootton, New Milton, Hants,
Dec. 21, 1906. Darlaston, Herbert William Hutton

31, Freer Road, Birchfield, Birmingham.
Feb. 28, 1911. Davidson, John

29, Federation Road, Abbey Wood,
Kent.
June 16, 1905. Davies, Daniel, F.R.M.S.

12, Eliot Hill, Blackheath, S.E.
April 28, 1914. Davies, Daniel Arthur

12, Eliot Hill, Blackheath, S.E.
June 24, 1913. Dean, Frank

1, Langham Street, Portland Place, W.
May 17, 1901. Deeley, George P.

Moushall, Amblecote, Brierley Hill, Staf-
fordshire.
April 25, 1916. Deey, Rev. Francis, M.A.

St. Bartholoinew' s Vicarage, So^ith Ber-
mondsey, S.E.
April 19, 1895. Delcomyn, Theo. A., F.R.M.S.

*' Feldheim," Wimbledon Common,
S.W.
Jan. 23, 1912. Dendy, Arthur, D.Sc, F.R.S. {President)

Vale Lodge, Hampstead Heath, N.W.
Feb. 23, 1915. Denne, M. T.

23, Hornsey Lane Gardens, Highgate, N.
Mar. 22, 1889. Dick, J.

Milber, Victoria Road, Mill Hill, N. W,
Feb. 15, 1907. Dilks, Arthur Charles, B.Sc.

Tardebigge, Bromsgrove.
June 24, 1913. Dinn, Harold H.

72, Elmwood Road, Heme Hill, S.E.
June 4, 1909. Dixon, Arthur L.

35, North Hill, Highgate, N,

XI

Date of Election.

June 17, 1892. Dixon-Nuttall, F. R., F.R.M.S.

" Ingleholme," Eccleston Parky near
Prescot, Lancashire.
Nov. 25, 1913. Dobell, Henry

74, Bahbacombe Road, Bromley, Kent.
Oct. 24, 1911. Downing, Owen Walter

23, Glenhouse Road, Eltham, Kent.
Mar. 17, 1899. Downs, Arthur

2, Ulverston Road, Walthamstow, E.
Nov. 23, 1915. Drake, Arthur Penrhyn, A.M.I.E.E.

83, Ingram Road, Park, Sheffield.
Nov. 23, 1909. Draper, Bernard M.

9, Pitt Street, Kensington, W,
Nov. 15, 1901. Druett, C. R.

330, Uxbridge Road, W,
April 27, 1915. Duncanson, John Richard

41, Atholl Mansions, S. Lambeth Road,
S.W.
Feb. 25, 1913. Durrad, John Wm., F.R.A.S.

350, Fosse Road North, Leicester.

June 19, 1891. Earland, Arthur, F.R.M.S.

34, Granville Road, Watford.
May 15, 1908. East, John Holtham

75, Moorland Road, Weston-super-Mare.
April 22, 1913. Edwards, Henry

22, aS'^. Bartholomew's Road, Reading.
Oct. 22, 1912. Edwardes, Seabury

Bhamo, Upper Burma.
Feb. 21, 1902. Edwards, Thomas Jarvis

9, >S'^. Lawrence Road, Brixton, S. W.
Oct. 22, 1912. Elliott, Wm.

97, Devonport Road, Shepherd's Bushy
W.
Mar. 22, 1910. Ellis, WiUiam Neale

The " Pharmacy," Appledore, Devon.
Nov. 28, 1911. Emsley, Harold Percy

31, Victoria Road, Wood Green, N.
Mar. 24, 1914. Engleheart, Conrad Wm.

6, Shaftesbury Villas, Kensington, W.

Xll

Date of Election.

Nov. 17, 1905. Evans, Morris B.

" Springwell," Hayes End Road, Middle-
sex.
April 27, 1915. Evans, Roy Gerald

5, Dean Road, Willesden Green, N.W.

Dec. 21, 1906. Fawcett, Henry Hargreave

Thorncombe, near Chard, Somerset,
June 24, 1913. Fendick, Ernest Alfred

22, Finedon Road, Wellingborough,
Northants.
June 16, 1893. Filer, Frank E.

35, Bancroft Road, Heme Hill, S.E.
Feb. 19, 1904. Finlayson, Daniel

" Redfern," Pellatt Grove, Wood Green, N,
Feb. 24, 1914. Finlayson, Raymond

22, Pellatt Grove, Wood Green, N,
Nov. 23, 1888. Flood, W. C.

119, Highbury Hill, N.
Mar. 25, 1913. Ford-Fone, W. Edwin

146, Palmers Road, New Southgate.
June 23, 1871. Freeman, Henry Edward

Walcot, Limes Avenue, New Southgate, N.
Dec. 16, 1898. French, Archibald J.

57, Ermine Road, Lewisham, S.E.
Jan. 18, 1907. Fuelling, George Ernest

195, High Road, Streatham, S.W.
Feb. 22, 1910. Fuller, Frederick Charles

7, Goldington Road, Bedford.
Nov. 21, 1902. Fuller, Wilham

24, Coleford Road, Alma Road, Wands-
worth, S.W.

May 15, 1903. Gabb, G. H., F.C.S.

83, Cray ford Road, Tufnell Park, N.
Nov. 25, 1913. Gamman, Robt.

13, Park Road, High Barnet.
Feb. 27, 1912. Gammon, Geo. Edwd.

6, Mackintosh Place, Roath, Cardiff.

Xlll
Date of Election.

Dec. 15, 1905. Gardner, Edward Lewis

1, Graven Road, Harlesden, N,W,
Jan. 20, 1899. Gardner, William, F.R.M.S.

292, Holloway Road, N.
Dec. 16, 1904. Garnett, Theodore, M.A. Oxon

South Bank, Grassendale, Liverpool.
Jan. 27, 1914. Gee, Harry Arthur

20, Buckler shury , E.G.
Mar. 28, 1916. Gillies, David

3, Hurst Road, Bexley, Kent.
Mar. 24, 1914. Gingell, Leonard Ralph

8, Grove Grescent, South Woodford.
Mar. 22, 1910. Gonville, Cyril H. K.

*' Roslin,'* Queen's Road, Buckhurst Hill,
N.
Feb. 24, 1914. Gooding, AKred Charles

53, Park Road, Battersea, S.W,
Dec. 28, 1909. Gooding, Henry Cornish

Stowmarket, Suffolk.
April 2, 1909. Gordon, Fred Wm., F.R.M.S.

" Graylands," Augustus Road, Wimble-
don Park, S.W.
Feb. 22, 1910. Gordon, John W.

113, BroadhurstGardens, Hampstead, N. W.
Jan. 25, 1910. Green, Frederick W.

42, Roxboro' Park, Harrow.
Jan. 16, 1903. Green, H. O.

4, Leamington Gardens, Seven Kings.
Jan. 26, 1915. Griffiths, Captain David

'' Sunny side," The Grove, Aldershot.
May 24, 1910. Grundy, James, F.R.M.S.

" Ruislip," Teignmouth Road, Grickle
wood, N.W.
June 25, 1912. Gurney, Joseph

Downs Farm, Pinner S.O., Middlesex.
Nov. 28, 1911. Guye, Dr. Paul

12, Rue de Gandolle, Geneva, Switzerland.

Nov. 24, 1914. Hamilton, Geo. Clarendon

''The Swallows/' Mill Hill, N.W,

XIV

Date of Election.

Feb. 22, 1910. Hammond, Alfred Gauntlett

101, Melody Road, Wandsworth^ S.W,

Jan. 25, 1910. Hammond, Arthur Rashdall

15, Genoa Road, Anerley, S.E.

April 26, 1910. Hammond, Leonard Frank

22, Mercers Road, N.
Oct. 22, 1886. Hampton, W.

The Manor House, Weston, Staffordshire.
Feb. 23, 1915. Handford, R. E.

41, Westwood Road, Goodmayes.
Mar. 28, 1916. Hardcastle, Alfred

17, FelsJmm Road, Putney, S.W.
Nov. 22, 1910. Harris, A. Wellesley, M.R.C.S., etc.

" Alnwick," Berlin Road, Cat ford, S.E.
May 19, 1905. Harris, Charles Poulet, M.D., M.R.C.S.,

L.R.C.P., F.R.M.S.

192, Lower Addiscomhe Road, Croydon.
Jan. 27, 1914. Harris, Leslie Edwin

19, Cheriton Square, Balham, S.W.
May 25, 1915. Hartley, W. E. T.

5, Pitt Terrace, Stirling, N.B.
Dec. 21, 1906. Hasslacher, Charles John

3, Kensington Park Gardens, W.
Mar. 28, 1879. Hawkins, C. E.

23, Dalebury Road, Upper Tooting, S.W.
June 13, 1914. Hawksley, Chas. Worthington

357, Cxford Street, W.
Nov. 26, 1912. Hay ward, Leslie Chas.
Feb. 15, 1901. Headley, F. W.

Uaileyhury College, Hertford.
Jan. 19, 1906. Heath, Charles Emanuel, F.R.M.S.

178, Loughboro' Road, Brixton, S.W.
April 20, 1906. Herbert, Robert Henry

6, Parkhurst Road, Holloway, N.

Feb. 21, 1908. Heron-Allen, Edward, F.L.S., F.G.S.,

F.R.M.S., F.R.Met.S., F.Z.S.

33, Hamilton Terrace, N.W., and Large
Acres, Selsey Bill, Sussex.
Dec. 20, 1901. Hicks, Frederick H.

8, Belmont Road, Wallington, Surrey,

XV
Date of Election.

Dec. 22, 1910. Higginson, George Neale

42, Bartholomew Road, Camden Town,
N.W.
Nov. 26, 1912. HiU, Wm., F.G.S.

" The Maples;' Hitchin.
Nov. 15, 1895. Hilton, A. E.

1, Highwood Avenue, North Finchley,
N.
May 15, 1908. Hiscott, Thomas Henry, F.R.M.S.

16, Woodville Road, Ealing, W,
May 27, 1913. Hoare, Stanley

17, Cor7iwall Terrace, Regent's Park, N. W.
Dec. 15, 1893. Holder, J. T.

114, Pepys Road, New Cross, S.E,
Feb. 26, 1875. Holford, Christopher

5, Northumberland Avenue, Upper Rich-
mond Road, Putney, S.W.
Dec. 20, 1907. Holmes, Frederick

217, Franciscan Road, Tooting, S.W,
June 25, 1912. Hook, Gerald Francis

97, Mortlake Road, Kew Gardens.
May 27, 1913. Hook, Reginald Vincent

9, Barrowgate Road, Chiswick, W.
Jan. 15, 1904. Hopkinson, John, F.L.S., F.G.S., F.R.M.S.

Weetwood, Watford.
Oct. 26, 1866. Horncastle, Henry

" Lindisaye," Woodham Road, Woking.
April 15, 1898. Hounsome, John

21, Edith Road, Plashet Grove, East
Ham, E.
Dec. 4, 1908. Howard, George

Sitwell Vale, Moorgate, Rotherham, Yorks.
Oct. 19, 1894. Howard, R. N., M.R.C.S., F.R.M.S.

The Cape Copper Co., Ookiep, Port
Nolloth, Namaqualand, Cape Colony,
South Africa.
Oct. 19, 1894. Hughes, F.

Wallfleld, Reigate.
Nov. 23, 1909. Huish, Charles Henry, F.R.M.S.

24, Champio7i Grove, Grove Lane, S.E.

XVI
Date of Election.

June 4, 1909. Hunter, John E.

** Strathblane," Park Road, Wallington,
Dec. 20, 1901. Hurrell, Harry Edward

25, Regent Street, Great Yarmouth.
Feb. 25, 1913. Hutchin, Chas. Duncan

c/o Meredith dh Drew, Ltd., High Street,
Shadwell, E.

May 24, 1867. Ingpen, J. E., F.R.M.S.

21, Wrotham Road, Broadstairs.
Feb. 16, 1906. Inwards, Richard, F.R.A.S.

6, Croftdown Road, Highgate Road, N. W,

Feb. 22, 1916. Jackson, James Joseph

30, Windsor Road, Wanstead, N.E.
Feb. 28, 1911. Jacob, Hugh Frederick Dawson, M.I.E.E.

B5, Clive Buildings, Calcutta.
Feb. 27, 1912. Jacobs, Reginald
April 26, 1910. Jervis, Rev. Edward S.

St. Peter's Vicarage, Streatham, S.W,
Nov. 24, 1914. Jewell, Harry

23, Beaty Avenue, Toronto, Canada.
Nov. 22, 1910. Jewell, Henry

152, Leathwaite Road, Clapham Common,
S.W.
Nov. 17, 1905. Jones, Arthur Morley

24, Grove Avenue, Hanwell, W.
April 26, 1910. Jones, George Fisher

Devonshire House, Osterley Park Road,
Southall, W.
Jan. 18, 1907. Jones, Rev. Robert Francis

28, Douglas Road, Canonbury, N.
Feb. 22, 1910. Jones, William Llewellyn

Manley Knoll, Helsby, Cheshire,
Feb. 22, 1910. Joshua, Edward Cecil

St. James's Buildings, William Street,
Melbourne, Victoria,

Nov. 17, 1905. Karleese, Benjamin

The Dell, Barnt Green, Worcestershire.

XVll

Date of Election.

May 23, 1873. Karop, G. C, M.R.C.S., F.R.M.S., etc.

Inniscorig, Beltinge Road, Heme Bay.
Feb. 26, 1913. Kaufmann, James C, LL.D.

49, Queen Street, Melbourne.
June 21, 1907. Kemp, Francis H. N. C.

15, Vernon Road, Hornsey, N.
July 25, 1884. Kern, J. J.

63, Queens Road, Beckenham, Kent.
Nov. 18, 1904. Kew, H. Wallis

3, Herndon Road, Wandsworth, S.W.
June 23, 1914. King, Chas. Jas. Reeves

64, Shell Road, Lewisham, S.E.
Nov. 23, 1915. King, Geo. W.

163, Boro' High Street, S.E.
May 17, 1901. Kirkman, Hon. Thomas, M.L.C., F.R.M.S.

Croftlands, Esperanza, Natal.
May 19, 1905. Kitchin, Joseph, F.R.M.S.

" Ingleneuk," 14, Brackley Road, Becken-
ham, Kent.
Mar. 22, 1889. Klein, S. T., F.R.A.S., F.L.S., F.R.M.S.

" Hatherlow," Raglan Road, Reigate.
Dec. 22, 1914. Knott, Dr. Frederick

'^ Karnak,'^ Upper Woodcote, Purley.
Oct. 28, 1913. Knox Stuart, G. E. Inman

9 Briardale Gardens, Hampstead, N.W.
Dec. 28, 1909. Knox, Sydney W.

61, Cambridge Street, Hyde Park, W»
Mar. 24, 1914. Koch Victor, M.E.

43, Elgin Avenue, Maida Vale, W.

Feb. 17, 1905. Lambert, Charles Alexander

Bank of New South Wales, Warwick^
Queensland.
Jan. 18, 1907. Larkin, Thomas Gaisford

29, Thornlaw Road, West Norwood,
S.E.
April 27, 1915. Lauwers, Walter

51, Temple Fortune Hill, Hampstead

Garden Suburb, N.W.
10

XVlll
Date of Election.

June 17, 1904. Lawrence, Frederick George

cjo Lionel Samson <&; Son, Cliff Street,
Fremantle, West Australia.
Feb. 25, 1913. Lawrence, Harry John

7, Norman Road, South Wimbledon, S.W.
April 26, 1910. Lawrence, William John

21, Cambridge Road, Lee, S.E.
Mar. 16, 1900. Lawson, Peter

" Jesmond," Nella Road, Fulham Palace
Road, S. W.
Jan. 1, 1909. Leadbeater, Herbert C.

81, Elborough Street, Southfields, S.W.
Jan. 20, 1905. Lees, Rev. Frederick Clare,

45, Cavendish Road, Sutton, Surrey.
Nov. 21, 1902. Leonard, Edward

14, Fairview Road, Oxton, Birkenhead.
Jan. 17, 1908. Levin, Major Arthur Everard, R.E. (T.)

" The Croft;' Bickley, Kent.
Feb. 22, 1910. Lewis, Frederic Henry

*' Ashmore," King's Avenue, Clapham
Park, S. W.
April 27, 1866. Lewis, R. T., F.R.M.S. {Hon. Reporter)

25, Craigerne Road, Blackheath, S.E.
Nov. 25, 1913. Liddon, Capt. Matthew Robert

12, Kensington Court, W.
June 26, 1868. Lindley, Sir Wm. H., M.Inst.C.E., F.G.S.

2d,BlittersdorffsPlatz,Frankfort-on-3Iain.
Mar. 24, 1914. Lloyd, Francis Wm.

85, Gracechurch Street, E.C.
Dec. 23, 1913. Lock, Thos. Benjn.

78, Riggindale Road, Streatham, S.W.
Mar. 23, 1915. Longmire, J.

23, Furnival Street, E.C.
Oct. 27, 1914. Loxton, Samuel E., F.R.A.S.

" Icknield," Little Aston, nr. Sutton Cold-
field.

May 25, 1883. Mainland, G. E., F.R.M.S.

14, The Norton, Tenby, South Wales.

XIX

Date of Election.

Nov. 24, 1914. McTavish, Alex.

Cowley Grove Cottage, Uxbridge.
Nov. 26, 1912. Mardon, Daniel Arthur

Avon Cottage, Grange Road, Bishops
S tort ford.
Jan. 24, 1911. Marsh, George Robertson, M.A.

Mallards Close, Twyford, near Win-
chester, Hants.
Feb. 15, 1895. Marshall, William John, F.R.M.S.

15, Elms Road, Dulwich Village, S.E.
May 18, 1906. Martin, William

" Ketklen," Burgh Heath, Epsom, Surrey.
Nov. 28, 1911. Martin, Wm. Julius
Jan. 15, 1892. Maw, W. H., F.R.M.S., F.R.A.S.

18, Addison Road, Kensington, W,
Mar. 28, 1911. Maxwell, Edward Kelly, B.A.

H.M. Patent Office, W.G.
May 19, 1893. Merhn, A. A. C. Eliot, F.R.M.S.

British Consulate, Volo, Greece.
Oct. 18, 1907. Mestayer, Richard L., M.I.C.E., F.R.M.S.

Lambton Quay, Wellington, New Zea-
land.
July 27, 1877. Michael, A. D., F.L.S., F.Z.S., F.R.M.S.

The Warren, Studland, near Wareham,
Dorset.
Feb. 25, 1913. Mills, Fdk. Wm., F.R.M.S.

Thornleigh Edgerton, Huddersfield.
Jan. 20, 1905. Milne, William

70, Beech Grove Terrace, Aberdeen.
Oct. 18, 1901. Moore, Harry, F.R.M.S.

12, Whiston Grove, Moorgate, Bother Jiam,
Yorks.
July 26, 1878. Morland, Henry

Cranford, near Hounslow.
June 4, 1909. Mortimer, Hugh Hamilton

20, Birchin Lane, E.G.
Jan. 16, 1891. Muiron, C.

49, Chatsworth Road, Brondesbury, N.W.
Dec. 23, 1913. Mumford, Frank Septimus

Belmont, Doncaster.

xz

Date of Election.

Nov. 22, 1910. Mummery, J. Howard, M.R.C.S.

Islips Manor, Northolt, Middlesex,
June 16, 1905. Myles, James Cellars

53, Garlyle Road, Manor Parky S» Essex.

Jan. 27, 1914. Nail, Rev. Geo. Herbert, M.A., F.R.M.S.

18, Deans Yard, Westminster , S.W.
Mar. 24, 1876. Nelson, E. M., F.R.M.S.

Beckington, Bath.
Feb. 15, 1907. Newman, Charles Arnold

Oundle, Northants.
May 27, 1913. Newmarch, Edgar Ribton

4, The Drive, Walthamstow, N.E.
Jan. 26, 1872. Newton, E. T., F.R.S., F.G.S.

Florence House, 13, Willow Bridge Road,
Canonbury, N.
Jan. 17, 1908. Nicholson, Alfred

19, Victoria Road, Salisbury.
June 23, 1914. Norman, Geoffrey

8, Cliffords Inn, B.C.
Nov. 28, 1911. Nutt, Hy. Francis

51, Gurdon Road, Charlton, S.E,

Feb. 25, 1913. Oatley, Wm.

Badcox, Frome
Feb. 16, 1900. O'Donohoe, T. A.

8, Myrtle Road, Acton, W,
Jan. 24, 1879. Offord, J. M., F.R.M.S.

3, Cleveland Gardens, West Ealing, W,
Dec. 22, 1876. Ogilvy, C. P., F.L.S.

Sizewell House, Leiston, near Saxmund-
ham, Suffolk.
May 17, 1907. Ogilvy, J. Wilson, F.R.M.S.

18, Bloomsbury Square, W.C.
Nov. 15, 1907. Oke, Alfred William, B.A., LL.M.

32, Denmark Villas, Hove.
June 23, 1914. Oldershaw, Martin Herbert

12, Perham Road West Kensington, W.
Nov. 18, 1892. Orfeur, Frank, F.R.M.S.

91, Effra Road, Brixton, S.W.

XXI

• Date of Election.

April 23, 1912. Owen, Wm. Hy.

19, Home Park Road, Wimbledon,
Dec. 27, 1867. Oxley, Frederick, F.R.M.S.

cjo A. E. Linton, Esq., Box 9, P.O.,
Nairobi, British East Africa,
Dec. 18, 1903. Oxley, F. J., M.R.C.S.

1, Dock Street, E.

Feb. 27, 1912. Palmer, Hy., J.P., F.R.G.S.

1, Pelaw Terrace, DurJuim.
Nov. 25, 1913. Panichelli, Frank

7, Rowan Road, Hammersmith, W.
April 10, 1910. Parfitt, Edward WiUiam

7, Gat combe Road, Tufnell Park, N,
Feb. 25, 1913. Parrott, Fdk. Wm.

" Morning side,'' Albert Road, Hale,
Cheshire.
Oct. 27, 1871. Parsons, F. A., F.R.M.S.

15, Osborne Road, Stroud Green, N,
Dec. 16, 1904. Patterson, George

20, Madrid Road, Castlenau, Barnes,
S.W.

Jan. 18, 1901. Paulson, Robert, F.L.S., F.R.M.S.

" Glenroy,'' Cecil Park, Pinner, Middle-
sex,
May 24, 1867. Pearson, John

40, Maida Vale, W,
May 20, 1904. Perks, Frederick John (Hon, Treasurer)

48, Grove Park, Denmark Hill, S,E,
Jan. 18, 1907. Perry, Francis Gough

2, The Cloisters, Gordon Square, W.C,
May 26, 1914. Peter, Henry Turing

15, Hanover Square, W.
Mar. 17, 1905. Phipps, William Joseph

132, Pinner Road, Oxhey, Herts,
Nov. 15, 1895. Pillischer, J., F.R.M.S.

88, New Bond Street, W,
April 25, 1910. Pinchin, Ernest Alfred, B.Sc.

4, Gleneldon Road, Streatham, S.W.
Nov. 26, 1912. Pitt, Edward

Madeley Ho., Gerrard's Cross, Bucks.

xxu

Date of Election.

Jan. 15, 1904. Pledge, John H., F.R.M.S. (Hon. Assistant

Secretary)

72, Nibthwaite Road, Harrow.
Nov. 23, 1883. Plowman, T.

Nystuen Lodge, Bycullah Park, Enfield,
Sept. 21, 1894. Pollard, Jonathan, F.R.M.S.

10, Porteus Road, Paddirhgton Green, W,
May 18, 1900. Poser, M., F.R.M.S.

St. PauVs Street, Rochester, N.Y.
June 21, 1895. Poulter, Christopher S.

Mount Lodge, Parkhurst Road, Bexley,
Kent.
May 17, 1901. Powell, David, M.A., F.R.M.S.

Over strand. Grove Park Road, Chiswick, W.
July 7, 1865. Powell, Thomas H., F.R.M.S.

Emsdale, Greenham Road, Muswell Hill,
N.
Dec. 20, 1907. Pratt, John Edwin

6, Heathfield Terrace, Seven Kings, Essex.
June 22, 1915. Price, Reginald A.

11a, Holland Road, Brixton, S.W.
Nov. 26, 1912. Pulford, Herbert, M.A., etc.

3, Ambleside Avenue, Streatham, S.W.

Nov. 6, 1908. Quick, Albert Hedley

" Inverness," Malvern Road, Thornton
Heath.

Jan. 18, 1901. Radley, Percy E., F.R.M.S.

30, Foxgrove Road, Beckenham, Kent.
Nov. 25, 1913. Ramsay, Ernest Wm., P.A.S.I.

16, Whiteley Road, Upper Norwood, S.E.
Mar. 28. 1916. Rasquin, Georges

46, Cunningham Park. Harrow-on-the-Hill.
Nov. 16, 1906. Reid, Duncan J., M.B., CM.

20, Blakesley Avenue, Ealing.
Mar. 20, 1896. Rheinberg, Julius, F.R.M.S.

23, The Avenue, Brondesbury Park, N. W,
Mar. 23, 1915. Ribbons, Joseph Lov^elace

" Greenhill'' Reynolds Road, Beacons field.

XXlll
Date of Election.

Sept. 18, 1891. Richards, F. W.

104, iS'^, Luke Street, Montreal, Canada.
Oct. 2, 1908. Richards, William

Heather Brae, Mayhury Hill, Woking.
Jan. 18, 1901. Richardson, John

28, Beaumont Avenue, Richmond, Surrey.
June 21, 1901. Robertson, Sir Helenus R., F.R.M.S.

Upton Grange, Chester.
Mar. 15, 1907. Robertson, James Alexander, F.R.M.S.

Sunny side, Fleetwood.
April 28, 1914. Robotham, Fras. Edward

48, Lillieshall Road, Clapham, S.W.
Nov. 16, 1900. Rogers, G. H. J., F.R.M.S.

55, King Street, Maidstone.
June 4, 1909. Rolph, Frank

Harts Stables, Woodford Green, E,
Jan. 25, 1884. Rosseter, T. B., F.R.M.S.

East Kent Club, Canterbury.
Jan. 26, 1883. Rousselet, Charles F. (Vice-President and

Hon. Secretary for Foreign Correspondethce),
Curator R.M.S.

Fir Island, Mill Hill, N.W.
Nov. 26, 1912. Row, Rd. Wm. Harold

36, Lexham Gardens, Kensington, S.W.
Nov. 18, 1904. Rowley, Frederick Richard, F.R.M.S.

8, Pinhoe Road, Heavitree, Exeter,
April 27, 1888. Russell, J.

16, Blacket Place, Newington, Edinburgh.

Mar. 24, 1914. St. George, Harry A.

112, Albany Street, Regent's Park, N.W.
April 2, 1909. Saxton, Thomas R., A.M.I.C.E., F.R.M.S.

43, East Bank, Stamford Hill, N.
Nov. 28, 1911. Schmerl, Augustus

34, St. Gabriel's Road, Cricklewood, N. W.
June 23, 1914. Scott, Wm. Hy.

63, Fellows Road, S. Hampstead, N.W.
June 20, 1890. Scourfield, D. J., F.Z.S., F.R.M.S. (Vice-
President)

63, Queen's Road, Leytonstone, E.

XXIV

Date of Election.

May 20,

1898.

Jan. 27,

1914.

Nov. 25,

1913.

Dec. 28,

1909.

May 26,

1876.

June 21,

1907.

Jan. 28,

1913.

Mar. 25,

1913.

Feb. 28,

1911.

June 19

Feb. 22

Oct. 21

Mar. 25
Mar. 17
Mar. 17

Nov. 18

Jan. 15

1896.

1910.

1904.

1870.
1899.
1905.

1898.

1892.

Sears, Robert S. W.

1, Lisson Grove, iV.TF.
Shelley, Geo. Hallett

51, Champion Grove, Denmark Hill, S.E,
Shepherd, Benjamin

Fir Cottage, Oak Lane, Bounds Green, N,
Shephard, John

Clark Street, South Melbourne, Victoria.
Shepheard, Thomas, F.R.M.S.

Kingsley, Bournemouth West.
Sheppard, Alfred William, F.Z.S., F.R.M.S.
(Hon. Editor)

1, Vernon Chambers, W.C.
Sheppard, Edwd. Jas., F.R.M.S.

137, Kennington Road, S.E,
Shuckard, David Hy.

14, Walerand Road, Lewisham, S.E,
Sidebottom, Henry

" Woodstock," Syddal Park, Bramhall,
Cheshire.
Sidwell, Clarence J. H., F.R.M.S. (Hon,
Curator)

46, Ashbourne Grove, Dulwich, S.E.
Simpson, Norman Douglas

Carlton Lodge, Wellingto7i Road, Bourne-
mouth.
Smith, Arthur Edgar

" Helios," 71, Fox Lane, Palmer's Green,
N,
Smith, F. L.

49, Belvedere Road, Upper Norwood, S.E.
Smith, Frank P.

2, King's Villas, Chase Road, Southgate.
Smith, Frederick

13, Rye Hill Park, Peckham Rye, S.E.
Smith, Thomas J., F.R.M.S.

c/o W. Watson cfc Sons, 313, High HoU
born, W.C.
Soar, C. D., F.L.S., F.R.M.S.

37, Dryburgh Road, Putney, S.W,

XXV

Date of Election.

Feb. 23, 1915. SoUis, Wm. Powell

26, Croxley Road, Maida Hill, W.
April 21, 1899. Spitta, Edmund J., L.R.C.P., M.R.C.S.,

F.R.A.S., F.R.M.S. (Vice-President)

41, Ventnor Villas, Hove, Brighton.
April 21, 1899. Spitta, Harold R. D., M.D., M.R.C.S.,

L.R.C.P., D.P.H.

12, Bolton Street, May fair, W,
Jan. 15, 1904. Sprague, T. B., LL.D.

West Holme, Woldingham, Surrey.
Jan. 28, 1913. Spry, Lt. Robt,, R.N., F.R.M.S.

83, Mount Gold Road, Plymouth.
Jan. 18, 1907. Stahl, Arthur

11, Scotts Avenue, Shortlands, Kent.
Jan. 25, 1916. Stephanides, Theodore

72, Westbourne Terrace, W.
Nov. 27, 1885. Stevenson, G. T.

Ravenscourt, Haling Park Road, South
Croydon.
June 18, 1897. Still, Arthur L.

Roslyn, Dower Avenue, WalUngton,
Nov. 16, 1894. Stokes, William B.

212, Notre Dame Street, West Montreal.
Dec. 15, 1893. Sturt, Gerald

" Lismore," Cavendish Road, Weyhridge,
Dec. 17, 1875. Swift, M. J., F.R.M.S.

6, Aylestone Avenue, Brondesbury, N. W.
Dec. 28, 1915. Syer, John

Stanmore Hill, Middlesex.

Nov. 28, 1879. Tasker, J. G.

30, Junction Road, Upper Holloway, N.
Oct. 16, 1896. Taverner, Henry, F.R.M.S.

319, Seven Sisters Road, Finshury
Park, N.
Feb. 17, 1905. Taylor, Thomas George

Ballaclague, Ellington Park Road, Rams-
gate.
Mar. 28, 1916. Tennant, John, M.A.

19, TheBoltons, S.W.

XXVI

Date of Election.

Dec. 22, 1865. Terry, John

8, Hopton Road, Coventry Park, Streat-
ham, 8.W.
Mar. 28, 1916. Thomas, Reginald Walter

15, Ambrose Avenue, Golders Green.
Mar. 26, 1912. Tibbie, Bertie Wallace

27, St. Paul's Road, Canonhury, N.
June 24, 1913. Tierney, Clarence M. S., B.Sc, F.R.M.S.

" Netherton," Coulsdon, Surrey.
May 16, 1902. Tilling, George, F.R.M.S. *

" Grasmere," Rydal Road, Sir eatham, S. W,

Nov. 25, 1913. Tilling, Wm. Geo.

20, Streathbourne Road, Upper Tooting,
S,W.
Nov. 24, 1914. Tindall, Wm. B.

39, St. Mary Street, Toronto, Canada.
Jan. 25, 1910. Todd, Charles Stephen

25, Hanover Road, Tottenham, N.
Feb. 27, 1912. Tomlinson, Edwd. Theodore

8, St. George's Square, S.W.
Nov. 26, 1912. Tonkin, Thos. S.

Bramley Avenue, Coulsdon, Surrey.
April 25, 1916. Topsent, Prof. Emile

Faculte des Sciences Dijon [Cote d'or),
France.
Dec. 21, 1894. Traviss, Will. R.

42, Winchester Avenue, Brondesbury ,N , W.
Feb. 25, 1913. Trotman, Alex. Chas.

28, Gubyon Avenue, Heme Hill, S.E.
Mar. 5, 1909. Troughton, Henry George

3, New Court, Lincoln's Inn, W.C.
June 17, 1892. Turner, C.

20, Minster Road, Cricklewood, N.W,
May 25, 1915. Tutt, John Francis Donald, F.R.C.V.S.

" Rothiemurchus," St. Cross, Winchester,
Feb. 25, 1913. Tyas, Rev. Vetranio

12, Felstead Road, Wanstead, N.E.

Jan. 24, 1914. Walker, Arthur

306, South Lambeth Road, S.W,

xxvu

Date of Election.

July 25, 1873. Walker, J. S.

6, Warwick Road, Upper Clapton, N.E.
Nov. 22, 1910. Watts, Geo. W.

103, Haverstock Hill, N.W.
June 16, 1899. Wedeles, James, F.R.M.S.

231, Flinders Lane, Melbourne, Australia,
Mar. 20, 1908. West, Joshua Cobbett

" Holly Cottage," Church Street, Sunhury-
on-Thames.
Feb. 25, 1876. Wheeler, George
Jan. 25, 1910. Whitehead, Henry, B.Sc. Lond.

23, Downie Terrace, Murray field, Edin-
burgh.
Nov. 26, 1912. Whitteron, Fred.

Toorak Avenue, Kooyong, nr. Melbourne,

Victoria.
Dec. 4, 1908. Wilkins, Thomas Smith

Eversley, Uttoxeter.
Nov. 23, 1877. Williams, G. S.

Tor Hill, Kingskerswell, Devon.
Nov. 24, 1914. WilHams, Rev. John B.

"The Limes," Exminster, Exeter.
April 27, 1915. WiUiamson, Wm.

79, Morningside Drive, Edinburgh.
Jan. 19, 1906. Wilson, Joseph, F.R.M.S.

3, West Park Road, Kew Gardens,
8.W.
Feb. 27, 1912. Wood, Fredk. Geo.

161, Walworth Road, 8.E.
Dec. 20, 1895. Wood, Walter J., F.R.M.S.

" Ernecroft," Abbey Road, Grimsby.
Nov. 16, 1894. Wooderson, Edwin

" Konigsfeld," 39, Dartmouth Road,
Brondesbury, N.W.
Mar. 15, 1907. Worssam, Cecil

17, Grafton Road, Bedford.
Jan. 18, 1907. Wright, Joseph Pepper

cjo Messrs. Davidson, Boules, Ld., 86,
Wellington Street, West Toronto,
Canada.

XXVlll

Date of Election.

Feb. 21, 1902. Wyatt, Edward

Gordonia, Gloucester Eoady Norhiton^
Kingston.
Jan. 18, 1901. Wykes, William

7, Plaistow Park Road, Plaistow, Essex,

Mar. 24, 1914. Yermoloff , His ExceUency Nicholas, K.C.V.O. ,

3, Whitehall Court, S.W. ]

Nov. 23, 1888. Young, G. W., F.G.S. ^

20, Grange Road, Barnes, S.W, j

NOTICE.

Members are requested to give early information to the Treasurer
of any chang-e of residence, so as to prevent miscarriagre of Journals
and Circtilars.

\

XXIX

List of Exchanges and of SociETtEs, etc., which

Receive the Journal.

American Microscopical Society, T. W. Galloway, Secretary,
Beloit College, Beloit, Wisconsin, U.S.A.

Bausch & Lomb Optical Company, Publication Department,

Rochester, N.Y., U.S.A.
Bergens Museums Bibliothek, Bergen, Norway.
Birkbeck College, Bream^s Buildings, Chancery Lane, W.C.
Birmingham Natural History and Philosophical Society,

Norwich Union Chambers, Congreve Street, Birmingham.
Botanical Society of Edinburgh (The Curator), The Botanic

Gardens, Edinburgh.
Botanisches Centralblatt, c/o Dr. J. P. Lotsy, Spaarne 17,

Haarlem, Holland.
Brighton and Hove Natural History Society, c/o The Public

Library, Brighton.
Bristol Naturalists* Society (The Librarian), 5, Lansdown

Place, Clifton, Bristol.
British Association for the Advancement of Science, Burling-
ton House, London, W.

Canadian Listitute, W. H. Vandersmitten, Esq., Secretary,
46, Richmond Street East, Toronto, Canada.

Concilium Bibliographicum, Ziirich-Neumiinster, Switzerland.

Croydon Natural History and Scientific Society (The Secre-
tary), Public Hall, Croydon.

Dohrn, Prof. Reinhart, The Zoological Station, Naples.

" English Mechanic,'' 5, Effingham House, Arundel Street,
W.C.

XXX

Entomological Society, 11, Chandos Street, Cavendish Square,

W.
Essex Field Club, Essex Museum of Natural History, Stratford,

Essex.

Geologists' Association (The Librarian), University College,
Gower Street, W.C.

Herts Natural History Society, c/o Daniel Hill, Esq., " Herga,'*

Watford, Herts.
Historical and Scientific Society of Manitoba, Winnipeg,

Canada.
Horniman Museum, Forest Hill, S.E. (The Curator).
Hull Scientific and Field Naturalists' Club, Royal Institution,

Hull.

Illinois State Laboratory of Natural History (Library),
Urbana, 111., U.S.A.

"Knowledge,'' The Knowledge Publishing Co., Ltd., 42,
Bloomsbury Square, W.C.

Leicester Literary and Philosophical Society, Dr. Stracey,
Hon. Librarian, Priory Lodge, New Walk, Leicester.

Library, Bureau of Science, Manila, Philippines.

Linnean Society, Burlington House, Piccadilly, W.

Literary and Philosophical Society of Manchester (The
Librarian), 36, George Street, Manchester.

Lloyd Library, Cincinnati, Ohio, U.S.A.

Manchester Microscopical Society, J. E. Storey, Esq., 26,
Grosvenor Road, Whalley Range, Manchester.

Microscopical Society of Liverpool, 19, Hockins Hey, Liver-
pool.

Missouri Botanical Garden, St. Louis, Mo., U.S.A.

Natural History Society of Northumberland, Durham, and
Newcastle-upon-Tyne (The Librarian), Hancock Museum,
Barras Bridge, Newcastle-upon-Tyne.

Natural History Branch of the British Museum (The

Librarian), South Kensington, W.
Natural History Society of Glasgow (The Librarian), 207,

Bath Street, Glasgow.
" Nature " (The Editor), St. Martin's Street, W.C.
Netherlands Zoological Society, Zoological Station, Helder,

Holland.
*' Nuova Notarisia,'' c/o Prof. G. B. De Toni, Universite

Royale de Modena, Modena, Italy.
" Nyt Magazin for Naturaidenskaberne,'' c/o Prof. Dr. N.

Wille, Botan. Garten, Christiania.

Optical Society (The Hon. Librarian), 39, Victoria Street, S.W.

Patent Office Library, 25, Southampton Buildings, Chancery

Lane, W.C.
Philadelphia Academy of Natural Sciences, Philadelphia, Pa.,

U.S.A.
Philippine Exposition Board, Calle General Solano 384,

Manila, Philippine Islands.

R. Scuola Superiore di Agricoltura, Portici, Italy.
Royal Dublin Society, Leinster House, Dublin.
Royal Institute of Cornwall, Truro.
Royal Institution, 21, Albemarle Street, W.
Royal Society of Medicine, 1, Wimpole Street, W.
Royal Microscopical Society, 20, Hanover Square, W.
Royal Society, Burlington House, Piccadilly, W.
Royal Society of New South Wales, Sydney.
Royal Society of Arts, John Street, Adelphi, W.C.

Smithsonian Institution, Washington, D.C.

Smithsonian Institution (United States National Museum),

c/o Wm. Wesley & Son, 28, Essex Street, Strand.
Societe Beige de Microscopic.
Societe Botanique Italienne, Florence, Italy.

Tempere, Mons. J., Grez-sur-Loing, par Bourron, Seine et
Marne.

XXXll

University of California Library (Exchange Department),
c/o Wm. Wesley & Son, 28, Essex Street, Strand,
London, W.C.

Victoria, Australia, Field Naturalists' Club of. A. D. Hardy,
Hon. Secretary.

Wagner Free Institute, Montgomery Avenue and 17th Street,

Philadelphia, U.S.A.
Wesenberg-Lund, Dr., Slotsgade, Hillerod, Denmark.
Wisconsin Academy of Sciences, Arts, and Letters (Exchange

Secretary), Madison, Wis., U.S.A.

OPFICEES AND COMMITTEE.

(^Elected February 1918.)

President:

A. B. Rendle, D.Sc, F.R.S.

Vice-Presidents:

C. F. RoussELET, Curator R.M.S.
D. J. ScouRFiELD, F.Z.S., F.R.M.S.

David Bryce.
Prof. Arthur Dendy, D.Sc, F.R.S.

M. A. AiNSLiE, R.N.,B.A.,F.R.A.S.

E. E. Banham.

C. H. Bestow, F.R.M.S,

N. E. Brown, A.L.S.

G. H. Gabb.

Jas. Grtjndy, F.R.M.S.

COIVIIVIITTEE :

A. MoRLEY Jones.

J. M. Offord, F.R.M.S.

R. Paulson, F.L.S., F.R.M.S.

C. D. Soar, F.L.S., F.R.M.S.

Chas. S. Todd.

J. Wilson, F.R.M.S.

Hon. Treasurer :

Frederick J. Perks, 48, Grove Park, Denmark Hill^ S.E.5,
to whom subscriptions should be sent.

Hon. Secretary:

James Burton, 8, Somali Road, West Hampstead, N.W.2,
to whom all correspondence should be addressed.

Hon. Sec. for Foreign Correspondence:

C. F. Rousselet, Curator R.M.S. , 4, St. Matthew's Drive, St.

Leonards-on-Sea.

Hon. Reporter :

Hon. Librarian :

A. George, " Clovelly,^' Beresford Road, Harrow, Middlesex.

Hon. Curator :

C J. H. Sidwell, F.R.M.S. 46, Ashbourne Grove, Dulwich, S.E,'22

Hon. Editor:

A. W. Sheppard, F.R.M.S., 1, Vernon Chambers, W.C.I.
JouRN. Q. M. C. Series II.— No. 83. 34

11

PAST PRESIDENTS.

-M-

^EDWIN LANKESTER, M.D., F.R.S. .
♦ERNEST HART ....

*ARTHUR E. DURHAM, F.R.C.S., F.L.S.
*PETER LE NEVE FOSTER, M.A. .
♦LIONEL S. BEALE, M.B., F.R.S.
♦ROBERT BRAITHWAITE,M.D., F.L.S.
♦JOHN MATTHEWS, M.D., F.R.M.S. .
♦HENRY LEE, F.L.S., F.G.S., F.R.M.S., F.Z.S
♦THOS. H. HUXLEY, LL.D., F.R.S. .
♦T. SPENCER COBBOLD, M.D., F.R.S

TT T ^

♦T. CHARTERS WHITE, M.R.C.S., L.D.S
F.R.M.S. .....

♦M. C. COOKE, M.A., LL.D., A.L.S. .
*W. B. CARPENTER, C.B., F.R.S.

A. D. MICHAEL, F.L.S., F.R.M.S. .

B. T. LOWNE, F.R.C.S., F.L.S. .

♦Rev. W. H. DALLINGER, LL.D., F.R.S.
F.R.M.S. .....

EDWARD MILLES NELSON, F.R.M.S.
♦J. G. WALLER, F.S.A. .

JOHN TATHAM, M.A., M.D., F.R.M.S.

Elected

July 1865.
1866.

5>

>)

J>

J>

JJ

5>

>J

))

JJ

1867-8.

1869.

1870-1.

1872-3.

1874-5.

1876-7.

1878.

1879.

)j

JJ

>j

1880-1.
1882-3.
1884.
„ 1885-6-7.
Feb. 1888-9.

„ 1890-1-2.
„ 1893-4-5.

1896-7.

1898-9.

JJ

JJ

♦GEORGE MASSEE, F.L.S.

Feb. 1900-1-2-3.

EDIVrUND J. SPITTA, L.R.C.P., M.R.C.S.,

F.R.A.S., F.R.M.S.
*E. A. MINCHIN, M.A., F.R.S.
ARTHUR DENDY, D.Sc., F.R.S.

* Decctised.

Feb. 1904-5-6-7.

Feb. 1908-11.

. Feb. 1912-16.

Ill

HONORAEY MEMBERS.

Date of Election.

Mar. 19, 1897. B. T. Lowne, M.D,, F.R.C.S., F.L.S. {Past

President)

34, Portlayid Road, Hove, Sussex.

May 18, 1906. Dr. Eugene Penard

»

Rue Topffer 3, Geneva,

Feb. 12, 1918. Thomas H. Powell, F.R.M.S.

" Emsdale," Greenham Rd.y Muswell
Hill, iV.lO.

IV

LIST OF MEMBERS.

M-

Date of Election.

Mar. 12, 1918. Adams, Basil Albert

R.E. Experimental Station, Porton, Salis-
bury.
Nov. 24, 1914. Adams, Walter

85a, Rushey Green, Catford, S.E.6.
Dec. 23, 1913, Ainslie, Maurice Anderson, R.N., B.A ,

F.R.A.S,

8, Woodville Road, Blackheoih, S.E.3.
Feb. 16, 1906. Akehurst, Sydney Charles, F.R.M.S.

60, Bowes Road, Palmer's Green, AM 3.
Oct. 23, 1917. Alabaster, Alfred William

5, Holland Road, Peverill, Plymouth.
April 25, 1916. Aldis, Arthur William

Kingsley Hotel, Hart Street, W.C.\.
Feb. 19, 1904. Allardice, Capt. William McDiarmid

St. Endellion, Port Isaac, R.S.O. Cornwall,
May 24, 1910. Allen, W^iUiam Nassau

*' Caerneagh," North Circular Road,
Dublin.
Jan. 28, 1913. Allison, Arthur Morris

49, Southdown Avenue, Brighton.
Jan. 26, 1915. Andrew, Jas. Grant

62, Grovelands Road, Palmer's Green ^

N.n.

Dec. 15, 1899. Angus, H. F., F.R.M.S.

83, Wigmore Street, Cavendish Square,
W.l.
Nov. 13, 1917. Ardaseer, Gustasp, F.R.P.S.

2, Dynevor Road, Richmond, Surrey
Feb. 25, 1913. Armitage, John Joseph, L.D.S.E.

5, Cavendish Place, W,\,
June 21, 1907. Arpin, John Edward

131, Castelnau, Barnes, S.W.l^

Date of Election.

Feb. 22, 1880. Ashe, A., F.R.M.S.

55, Warrior Square, Soidhend-on-Sea.
April 17, 1903. Bagshaw, Walter, J.P., F.R.M.S.

" Moor field," Birkenshaw, near Bradford^
Yorks.
Sept. 26, 1884. Baker, F. W. Watson, F.R.M.S.

313, High Holhorn, W.C.I,
Mar. 16, 1906. Baker, Henry James

13, Moor gate Street, E.G. 2.
April 2, 1909. Baker, Wilfred E. Watson

313, High Holhorn, W.G.I.
Nov. 26, 1913. B^le, Wm. Mountier, F.R.M.S.

83, Walpole Street, Kew, Victoria, Australia^
June 19, 1908. Banham, Edward Elliott

38, Harbor o' Road, KingstJiorpe, North-
ampton.
May 28, 1912. Barnard, Edward Jas.

10, Denver Road, Stamford Hill, iV.16-^
Feb. 26, 1913. Barnard, Joseph Edwin, F.R.M.S.

Park View, Brondeshury Park, N.W.^.
Mar. 19, 1886. Barnes, W.

23, Jackson Road, Holloway, N.l.
May 28, 1912. Barratt, Thos. Franklin

*' Bell Moor," Hampstead Heath, N.W.3,
Nov. 26, 1912. Bassett, Ernest Henry

43, Amherley Road, Palmer's Green, N.\^.
June 17, 1892. Bates, C.

1, Windsor Road, Denmark Hill, S.E.6.
Oct. 18, 1895. Baugh, J. H. A.

63, Cambridge Road, Hammersmith, Tf .6.
June 4, 1909. Baxendale, Frederick G.

Gorbally, Arbrook Lane, Esher.
Jan. 16, 1891. Baxter, W. E., F.R.M.S.

170, Ghurch Street, Stoke Newington, N.\Q.
Oct. 27, 1914. Beattie, Wm.

8, Lower Grosvenor Place, S.W.\.
Nov. 26, 1875. Beaulah, John

Albert House, Brigg.
July 25, 1884. Beck, C, F.R.M.S.

68, Gornhill, E.G.3.

VI

Date of Election.

June 27, 1911. Bennett, Lionel C.

49, Erpingham Road, Putney, S.WA5.
Feb. 16, 1906. Bestow, Charles H., F.R.M.S.

43, Upper Clapton Road, E.5.
Mar. 28, 1916. Bevington, Reginald, H. S.

28, Cannon Street, E.CA.
Oct. 26, 1915. Bilham, Ernest Q.

Town Hall, Bethnal Green, E.2,
Feb. 27, 1917. Billinghurst, Humphrey Godwin

76, Lebanon Gardens, Wandsworth ,
S.W.IS.
Nov. 13, 1917. Birch, Wilfrid John

Pte 523335, 6th San. Sect., Moore Bar-
racks Hospital, Shorncliffe.
June 16, 1905. Blair, William Nisbet

23, West Hill, Highgate, N.Q>.
Oct. 2, 1908. Blockley, Edgar A.

27, Bcechwood Avenue, Keiv Gardens,
May 19, 1899. Blood, Maurice, M.A., F.C.S., F.R.M.S.

51, Winchester Avenue, Brondesbury,
N.W,6.
Feb. 22, 1916. Bocock, Chas. Hanslope

The Elms, Ashley, Kewinarkei.
Jan. 25, 1915. Boltz, Arthur

21, Ashbridge Road, Leytonstone, E.ll.
Feb. 25, 1913. Booker, Alfred James

37, Claremont Road, Highgate, N.Q.
April 25, 1911. Bowtell, Alexander Jas.

123, Dalston Lane, E.S.
Nov. 23, 1915. Bradbury, John Geo.

1 , Hogarth Hill, Finchley Road, Hendon,
N.WA.
Nov. 15, 1907. Bradford, William Barnes

54, Lombard Street, E.C.S.
Mar. 24, 1914. Brand, Felix R. W.

37, Hatton Garden, E.C.I.
Nov. 17, 1905. Bremner, John Unthank

277, King Street, Hammersmith, W.Q.
Jan. 24, 1911. Bridge, Samuel

28, Larkhall Rise, Clapham, >S'. ir.4.

Vll

Date of Election.

Nov. 6, 1908.

June 11
Feb. 23
Dec. 4

Dec.

19,

1890.

Mar.

15,

1907.

May

24,

1910.

Jan.

18,

1907.

Jan.

28,

1887.

May

14,

1918.

May

22,

1917.

Mar.

18,

1904.

Jan.

15,

1892.

May

28,

1912.

May

15,

1908.

Jan.

20,

1905.

Feb.

28,

1913.

Mar.

12,

1918.

1918.
1915.
1908.

Broad, John Moxon

2, Nicoll Road, Harlesden, iV.lT.lO.
Brokenshire, Frederick A.

2, Rock Avenue, Barnstaple.

Brooke, Chas. Hy. Alfred ^

159, Sutherland Avenue, W.9.
Brooks, Theodore, F.R.M.S.

Sta Clara Province, Central Caracas,
Caracas, Cuba.
Brough, J. R.

' ' Eversley," Shepherd's Hill, Highgate, N.Q,
Browett, William

" Beaumont," Pear field Road, Forest
Hill, S.E.2S.
Brown, Edward George

8, Freke Road, Battersea, S.W.W.
Brown, Nicholas Edward, A.L.S.

6, The Avenue, Keiv.
Browne, E. T., M.A., F.R.M.S.

Anglefield, Berkhamsted, Herts.
Browning, Edgar W. F.

89, Disraeli Road, Putney, S.W 1^.
Browning, Frederick

27, Cornford Grove, Balham, S.W.12.
Brushfield, N. W.

13, Allfarthing Lane, Wandsworth Com-
mon, S.W.l^.
Bryce, David [Vice-President)

37, Brooke Road, Stoke Newingion, N 16;
Bull, Albert Edwd.

3, Canterbury Terrace, Sudbury, Harrow,
Bunting, Percival J.

40, Pope Street, Belle Vue East, Jolmn-
nesburg, S.A.
Burnell, Charles Edward

29, High Street, Shepton Mallet.
Burns, Dr. Nesbitt, M.B., B.A., F.R.S.E.

" The Lodge,'* Highbridge, Somerset.
Burrell, Edward John

11, Lower Park Loughton, Essex.

vm

Pate of Election.

April 20, 1906. BurrelJ, T. Leonard .

20, Upper Hornsey Rise, Islington, iV.19.
Jan.. 23, 1917. Burt, Charles Spiller

9, FantJiorpe Street, Putney, S.W.
April 28, 1914. Burton-Brown, Gerald Burton, M.D.

112, Tonbridge Road, Maidstone,
Feb. 19, 1904. Burton, James {Hon. Sec),

8, Somali Road, West Hampstead,
N.W.2.
Nov. 28, 1916. Bushell, C. W.

88, Hawthorn Parade, Haber field, Sydney,
N.S.W.
May 26, 1914. Buttemer, Robt. Wm., F.C.S., M.I.A.E.

aS'^. Mary's, Godalming.
Feb. 19, 1904. Butterworth, Arthur Cyrus,

Granville, Crowstone Road, Westdiff -on-
Sea,

April 15, 1904. Caffyn, Charles Henry

32, Falkland Road, Hornsey, N,
June 18, 1897. Campbell, Colney

96, New River Crescent, Palmers Green ^
N.13.
Mar. 16, 1906. Capell, Bruce John, F.R.M.S.

10, Castelnau, Barnes, S,W.l3.
May 24, 1910. Carruthers, Ferdinand Gilbert

27, Mosley Street, Newcastle-on-Tyne.
Jan. 25, 1910. Carter, John Arthur

6, Temple Road, Stowmarket.
June 17, 1892. Chaloner, G., F.C.S.

South Street, Colyton, S.O., Devon,
April 24, 1917. Chappie, Wm. Richard

2, St. George's Avenue, Aldermanhury ^

E.C.2.
June 28, 1910. Charlton, Alfred Edward

18, Bloomsbtiry Square, W.G.I.
Oct. 26, 1909. Cheavin, Harold Squire, F.R.M.S.

70, Somerset Road, H udders field.
AprU 22, 1913. Cheshire, Frederic John, F.R.M.S.

23, Carson Road, Dulwich, S.E.2.

Date of Election.

Mar. 22, 1878. Chester, The Very Rev. the Dean of

The Deanery^ Chester,
Dec. IS, 1896. Chipps, F. W.

201, Castelnau, Barnes, S.\V.\^,
Jan. 20, 1905. Christie, John, F.E.M.S.

Henleigh, Kingston Hill, Surrey.
Mar. 17, 190i). Gemence, Walter

14, Beckenham Grove, Shortlands.
Jan. 27, 1914. CHbborn, Lt.-Col. John

87, Victoria Street, S.W.I,
Oct. 18, 1907, ColdAvells, William Henry

Redcote, Shirley Road, Wallington,
June 11, 1918. Collins, William George

Trefriw, Highworth Avenue, Cambridge.
Oct. 21, 1904. Conrady, Alexander Eugen, F.R.A.S.

23, Flanchford Road, Stamford Brook ^
W.12.
Mar. 25, 1913. Cook, John Thomas

216, Clive Road, West Dulwich, S.E. 21,
April 28, 1914. Cooley- Martin, Francis

" Hillside,'' Porfsdown, Cosham, Hants.
Nov. 26, 1912. Coon, Joseph May

'' Morwenna,'^ St. Austell.
Jan. 18, 1901. Cox, Thomas N.

Hill Cottage, Bencomhe Road, Purley.
Jan. 15, 1904. Cox, William

" The Pound," Ling field, Surrey.
Jan. 25, 1910. Crabtree, James Fox, B.A.

40, Brazennose Street, Manchester.
April 27, 1915. Craig, Rev. S. Runsie

" Craigmount,'' Central Hill, Upper
Norwood, S.E. 19.
Nov. 25, 1913. Creese, Edward J. E., F.Z.S., F.R.M.S.

29, Cornford Grove, Balham, S.W. 12,
Nov. 21, 1902. Cressey, Dr. G. H.

Oak Manor, Tonbridge.
Aug. 28, 1868. Crisp, Sir Frank, LL.B., V.P.L.S., B.A.,.

F.R.M.S., F.G.S., F.Z.S.

5, Lansdowne Road, Notting Hill,
W.U.

X

Date of Election.

Nov. 16, 1906. Crosbie, Walter

Kenilworth, Willenhall, New Barnet.
Feb. 16, 1900. Crossland, R. E., A.R.I.B.A.

9, King's Bench Walk, Temple, E.CA.
Mar. 16, 1894. Culshaw, Rev. George H., M.A.

The Rectory, Iver Heath, Bucks.
May 22, 1917. Cunningham, W. T. P.

77, The Grove, Palmers Green, iV.13.
Jan. 16, 1903. Curties, C. Lees

244, High Holborn, W.C.I.
May 18, 1906. Cuzner, Edgar, F.R.M.S.

36, Trothy Road, Bermondsey, S.EA.
Nov. 18, 1904. Dade, Willoughby Dreyer

9, Bincleaves Road, Weymouth.
Jan. 17, 1908. Dallas, Charles Caldwell, F.R.G.S., F.Z.S.

Eastley Wootton, New Milton, Hants.
Dec. 21, 1906. Darlaston, Herbert William Hutton

31, Freer Road, Birchfield, Birmingham.
Feb. 28, 1911. Davidson, John, B.Sc.

Ill, Queen Street, Cardiff.
June 16, 1905. Davies, Daniel, F.R.M.S.

12, Eliot Hill, Blackheath, S.E.Z.
June 24, 1913. Dean, Frank

1, Langham Street, Portland Place,
W.\ .
May 17, 1901. Deeley, George P.

Moushall, Amhlecote, Brierley Hill, Staf'
fordshire.
April 19, 1895. Delcomyn, Theo. A.,

'' Feldheim," Wimbledon Common,
S.W.l^,
Jan. 23, 1912. Dendy, Arthur, D.Sc.,F.R.S. {Vice-President)

Vale Lodge, Hampstead Heath, iV.TF.3.
Feb. 23, 1915. Dcnne, M. T.

Henley House, Upper Warlingham,
Surrey.
Mar. 22, 1889. Dick, J.

Milber, Victoria Road, Mill Hill, N.W.I.
Feb. 15, 1907. Dilks, Arthur Charles, B.Sc.

Tardebigge, Bromsgrove.

XI

Bate of Election.

-June 17, 1892. Dixon-Nuttall, F. R., F.R.M.S.

" IngleJiolme," Eccleston Park, near
Prescot, Lancashire.
Nov. 25, 1913. Dobell, Henry

74, Bahhacomhe Road, Bromley, Kent,
.^•Oct. 24, 1911. Downing, Owen Walter

23, Glenhouse Road, Eltham, S.E.^.
-Mar. 17, 1899. Downs, Arthur

2, Ulverston Road, Walthamstow, E.\l .
Xov. 23, 1915. Drake, Arthur Penrhjai, A.M.LE.E.

51, The Chase, Nottingham.
:Nov. 23, 1909. Draper, Bernard M.

9, Pitt Street, Kensington, W.S.
:Nov. 15, 1901. Druett, C. R.

330, U^bridge Road, W.12.
-Jan. 8, 1918. Duncan, Francis Martin

11 , St. Leonards Road, East Sheen f S .W .14:,
April 27, 1915. Duncanson, John Richard

41, Atholl Mansions, S. Lambeth Road,
S.W.^.
rFeb. 25, 1913. Durrad, John Wm., F.R.A.S.

350, Fosse Road North, Leicester,

June 19, 1891. Earland, Arthur, F.R.M.S.

34, Granville Road, Watford.
-June 26, 1917. Edgar, Joseph

S, Newman Street, W .\.
April 22, 1913. Edwards, Henry

22, aS'^. Bartholomew's Road, Reading.
-Oct. 22, 1912. Edwardes, Seabury

Bhamo, Upper Burma.
JB'eb. 21, 1902. Edwards, Thomas Jarvis

9, St. Lawrence Road, Brixton, S.W. 2.

Oct. 22, 1912. Elliott, Wm.

97, Devonport Road, Shepherd's Bush,

W.12.

Mar. 22, 1910. Ellis, WiUiam Neale

The " Pharmacy ,'' Apj^ledore, Devon.
Nov. 28, 1911. Emsley, Harold Percy

31, Victoria Road, Wood Green, N.22.

Date of Election.

Mar. 24, 1914. Engleheart, Conrad Wm.

6, Shaftesbury Villas, Kensington, TF.81-
Nov. 17, 1905. Evans, Morris B.

" Springivell," Hayes End Boad, Middle^
sex.
June 26, 1917. Evans, John Goodbart

Kelleythorpe Park Road, Hale, Cheshire*
April 27, 1915. Evans, Roy Gerald

9, Chertsey Road, Redland, Bristol,
Mar. 12, 1918. Evens, Eric Doddrell

8, Christchiirch Road, Hampstead, N.W.3^ .

Dec. 21, 1906. Fawcett, Henry Hargreave

Thorncomhe, near Chard, Somerset*
June 24, 1913. Fendick, Ernest Alfred

22, Finedon Road, W ellinghoroiighi
Northants.
June 16, 1893. Filer, Frank E.

Glyn House, Ewell, Surrey.
Feb. 19, 1904. Finlayson, Daniel

" Redfern," Pellatt Grove, Wood Greeni.,
N.22.
Feb. 24, 1914. Finlayson, Raymond

22, Pellatt Grove, Wood Green, N.22..
Nov. 28, 1916. Fletcher, Joseph, B.D., 'B.A.

17, Fairfield Road, Croydon.
Nov. 23, 1888. Flood, W. C.

119, Highbury Hill, N.5.
Jan. 23, 1917. Flower, John William, A.MJ.E.E.

" Woodside,'' The Avenue, Muswell Hill,
iV.6.
Mar. 25, 1913. Ford-Fone, W. Edwin

146, Palmers Road, New Southgate, N.\l..
April 9, 1918. Fox, Alfred Harry Matthews

96, Lewin Road, Streatham, S.W .\(S.
June 23, 1871. Freeman, Henry Edward

69, Limes Avenue, New Southgate, JNMl..
Dec. 16, 1898. French, Archibald J.

57, Ermine Road, Lewisham, S.E.l^.

Xlll
'Date of Election.

.J"an. 18, 1907. Fuelling, George Ernest

195, High Road, Streatham, S.W.16.
iFeb. 22, 1910» Fuller, Frederick Charles

7, Goldiivgton Road, Bedford.

May 15, 1903. Gabb, G. H., F.C.S.

83, Cray ford Road, Tufnell Park, N.l.
JJ^ov. 28, 1916. Gadsden, J.

" Ferndale,'' Kew, Melbourne.
JNTov. 25, 1913. Gamman, Robt.

13, Park Road, High Barnet,
3)ec. 15, 1905. Gardner, Edward Lewis

1, Graveyi Road, Harlesden, N.W.IO,
^Jan. 20, 1899. Gardner, William, F.Pv.M.S.

292, Holloway Road, N.l.
€>ec. 16, 1904. Garnett, Theodore, M.A. Oxon

South Bank, Crrassendale, Liverpool.
.^Jan. 27, 1914. Gee, Harry Arthur
.May 23, 1916. George,^Alfred

" Clovelly,'' Beresford Road, Harrow,
Middlesex.
IMar. 28, 1916. Gillies, David

3, Hurst Road, Bexley, Kent.
"Mar. 24, 1914. Gingell, Leonard Ralph

111b, High Street, Hastings.
IVIar. 22, 1910. Gonville, Cyril H. K.

" Roslin," Queen's Road, Buckhurst Hill,
N.
tFeb, 24, 1914. Gooding, Alfred Charles

53, Park Road, Battersea, S.W. II.
^Dec. 28, 1909. Gooding, Henry Cornish

Stoivmarket, Suffolk.
t-Feb. 12, 1918. Goodman, Alexander

137, Adelaide Road, Primrose Hill, iY.ir.3.
April 2, 1909. Gordon, Fred Wm., F.R.M.S.

" Graylands," Augustus Road, Wimble-
don Park, S.W. 19.
f^eb. 22, 1910. Gordon, John W.

113, Broadhurst Gardens, Hampstead,
N.W.Q.

XIV
Date of Election.

Jan. 25, 1910. Green, Frederick W.

42, Roxhoro' Park, Harrow.
June 11, 1918. Green, Henry Frederick

20, Denbigh Road, West Ealing, Tf .13..

Jan. 16, 1903. Green, H. 0.

4, Leamington Gardens, Seven Kings,
May 24, 1910. Grundy, James, F.R.M.S.

'' Ruislip," Teignmouth Road, Cricile^
wood, N.W.2.
June 25, 1912. Gurney, Joseph

Downs Farm, Pinner S.O., Middlesex.

Nov. 28, 1911. Guye, Dr. Paul

12, Rue de Candolle, Geneva, Switzerland^-

Nov. 24, 1914. Hamilton, Geo. Clarendon
Feb. 22, 1910. Hammond, ^Alfred Gauntlett

101, Melody Road, Wandsworth, S.WJS:
Oct. 22, 1880. Hampton, W.

The Manor House, Weston, StaffordsJiire^
Mar. 28, 1916. Hardcastle, Alfred

179, Felsham Road. Putney, S.W.\5.
May 19, 1905. Harris, Charles Poulct, M.D., M.E.C.S.,.

L.R.C.P., F.R.M.S.

192, Lower Addisccmhe Road, Croydon^.
Jan. 27, 1914. Harris, Leslie Edwin

19, Cheriton Square, Balham, S.W.M.
May 25, 1915. Hartley, Walter E. T.

5, Pitt Terrace, Stirling, N.B.
Dec. 21, 1900. Hasslachcr, Charles John

3, Kensington Park Gardens, W.ll.
Mar. 28, 1879. ILiav kins, C. E.

23, Dalehury Road, Uj^fcr Tooting^
S.WM.
June 13, 1914. Hawksloy, Chas. Worthinglon

115, Fellowes Road, S . Ha mpstead, N .W 3.
Feb. 15, 1901. Hcadley, F. W.

Huileybury College, Hertford.
May 22, 1917 Hcarson, Charles E.

5, Templar Street, Camherwell, S.E.5,

XV
Date of Election.

Jan. 19, 1906. Heath, Charles Emanuel, F.R.M.S.

178, Loughhoro' Eoad, Brixton ^ S,W,d.
Nov. 28, 1916. Hensman, Leonard Newton

2, Killarney Road, Wandsworth^ S.W.IS-,
April 20, 1906. Herbert, Robert Henry

74, Welldon Crescent, Harrow.
Feb. 21, 1908. Heron-Allen, Edward, E.L.S., F.G.S.,

F.R.M.S., F.R.Met.S., F.Z.S.

33, Hamilton Terrace, N.W.^, and Large
Acres, Selsey Bill, Sussex.
Dec. 20, 1901. Hicks, Frederick H.

8, Belmont Road, Wallington, Surrey.
Dec. 22, 1910. Higginson, George Neale
Dec. 11, 1917. Hight, Edward

Cleve Hall, Champion Hill, S.E.5.
Nov. 28, 1916. Hill, Arthur Stanley

Royal Colonial Institute, Northumber'
land Avenue, Tr.C.2.
May 23, 1916. Hill, Cyril F.

Druids Croft, Kinnaird Avenue, Bromley ^
Kent.
Nov. 26, 1912. Hill, Wm., F.G.S.

" The Maples,'' Hitchin.
Nov. 15, 1895. Hilton, A. E.

1 , Highwood Avenu e, NorthFinchley, iV. 1 2 ..
Jan. 8, 1918. Hirst, Stanley

British Museum (Natural History) , Cram'
well Road, S.W.I.
May 15, 1908. Hiscott, Thomas Henry, F.R.M.S.

16, Woodville Road, Ealing, Tf .5.
May 27, 1913. Hoare, Stanley

71, Avenue Road, Regent's Park, N.W.l^
Dec. 15, 1893. Holder, J. T.

114, Pepys Road, New Cross, S.E. 14:.
May 14, 1918. HoUis, George Thomas

41, Sussex Street, E. 14.
Dec. 20, 1907. Holmes, Frederick

217, Franciscan Road, Tooting, S.W.ll.
June 25, 1912. Hook, Gerald Francis

97, Morilake Road, Kew Gardens.

XVI

Date of Election.

May 27, 1913. Hook, Reginald Vincent

9, Barrowgate Road, Chiswick, WA.
Jan. 15, 1904. Hopkinson, John, F.L.S., F.G.S., F.R.M.S.

Weetwood, Watford.
ApTil 15, 1898. Hounsome, John

21, Edith Road, Plashet Grove, East
Ham, E.Q.
Dec. 4, 1908. Howard, George

Sitwell Vale, Moorgate, Rotherham, Yorks,
Oct. 19, 1894. Howard, R. N., M.R.C.S., F.R.M.S.

The Cape Copper Co., Ookiep, Port
Nolloth, Namaqualand, Cape Colony,
South Africa.
Oct. 19, 1894. Hughes, F.

Wall field, Reigate.
Kov. 23, 1909. Huish, Charles Henry, F.R.M.S.

" The Limes,'' London Road, Redhill.
June 4, 1909. Hunter, John E.

" Strathblane," Park Road, Wallington.
Dec. 20, 1901. Hurrell, Harry Edward

25, Regent Street, Great Yarmouth.
Feb. 25, 1913. Hutchin, Chas. Duncan

cjo Meredith d; Drew, Ltd., High Street,
Shadwell, E.\.

May 24, 1867. Ingpen, J. E., F.R.M.S.

21, Wrotham Road, Broadstairs.
Feb. 16, 1906. Inwards, Richard, F.R.A.S.

6, Croftdown Road,Hig}i{/ate Road, N. W.5.

Feb. 22, 1916. Jackson, James Joseph

30, Windsor Road, Waiistead, E.l.
Feb. 28, 1911. Jacob, Hugh Frederick Dawson, M.I.E.E.

B5, Clive Buildings, Calcutta.
April 26, 1910. Jervis, Rev. Edward S.

St. Peter's Vicarage, Streatham, S.W.\^.
Nov. 24, 1914. Jewell, Harry

23, Bcaty Avenue, Toronto, Canada.
JSTov. 22, 1910. Jewell, Henry

152, Leathwaite Road, Clapham Common,
S.W.U.

XVll
Date of Election.

Feb. 27, 1917. John, Ambrose Hilton, M.B.B.S. Lond.

6, Brook Street, Stoke-on-Trent.
Nov. 17, 1905. Jones, Arthur Morley

24, Grove Avenue, Hanwell, W.l,
April 26, 1910. Jones, George Fisher

Devonshire House, Osterley Park Road^
Southall, W.
Jan. 18, 1907. Jones, Rev. Robert Francis

28, Douglas Road, Canonbury,N.l.
Feb. 22, 1910. Jones, William Llewellyn

Manley Knoll, »Helsby, Cheshire.
Feb. 22, 1910. Joshua, Edward Cecil

>S'^. James's Buildings, William Street,
Melbourne, Victoria.

Nov. 17, 1905. Karleese, Benjamin

The Dell, Barnt Green, Worcestershire.
May 23, 1873. Karop, G. C., M.R.C.S., F.R.M.S., etc.

Inniscorig, Belting e Road, Heme Bay.
Feb. 25, 1913. Kaufmann, James C, LL.D.

49, Queen Street, Melbourne.
June 21, 1907. Kemp, Francis H. N. C.

15, Vernon Road, Hornsey, N.8, •;■

July 25, 1884. Kern, J. J.

63, Queens Road, Beckenham, Kent.
Nov. 18, 1904. Kew, H. Wallis

3, Herndon Road, Wandsworth, S.W.IS.
Jan. 23, 1917. Kiell, John

1 9 , Stapleton Road , Upper Tooting, S .W.ll.
June 23, 1914. King, Chas. Jas. Reeves

64, Shell Road, Lewisham, S.E.IS.
Nov. 23, 1915. King, Geo. W.

163, Boro' High Street, S.E.I.
May 17, 1901. Kirkman, Hon. Thomas, M.L.C., F.R.M.S.

Croftlands, Esperanza, Natal.
May 19, 1905. Kitchin, Joseph, F.R.M.S.

" Ingleneuk," 14, Brackley Road, Becken-
ham, Kent.
Mar. 22, 1889. Klein, S. T., F.R.A.S., F.L.S.

" Hatherlow," Raglan Road, Reigat^.
JouRN. Q. M. C, Series II.— No. 83. 3^

XVlll
Date of Election.

Oct. 28, 1913. Knox Stuart, G. E. Inman
Dec. 28, 1909. Knox, Sydney W.

61, Cambridge Street, Hyde Parky H'.2.

Feb. 17, 1905. Lambert, Charles Alexander

c/o Bank of Neiu South Wales, Melbourne,
Victoria.
Jan. 18, 1907. Larkin, Thomas Gaisford

29, Thornlaw Road, W, Norwood j S.E.21.
April 27, 1915. Lauwers, Walter

51, Temple Fortune Hill, Hampstead
Garden Suburb, N.WA.
June 17, 1904. Lawrence, Frederick George

cfo Lionel Samson dh Son, Cliff Street,
Fremantle, West Australia.
Feb. 25, 1913. Lawrence, Harry John

7, Norman Road, South Wimbledon,
S.WM).
April 26, 1910. Lawrence, William John

21, Cambridge Road, Lee, S.E.3.
Mar. 16, 1900. Lawson, Peter

13, Nella Road, Fulhani Palace Roud,
S.W.6.

Nov. 13, 1917. Lawson, Stuart

30, Marlborough Road, Chiswick, WA.
Jan. 20, 1905. Lees, Rev. Frederick Clare,

45, Cavendish Road, Sutton, Surrey,
May 23, 1916. Leeson, John Rudd, M.D., F.L.S., F.R.M.S.

Clifden House, Heath Road, TwickenJmm.
Nov. 21, 1902. Leonard, Edward

14, Fairview Road, Oxton, Birkenhead.
Feb. 22, 1910. Lewis, Frederic Henry

" Ashmore," King's Avenue, Clapham
Park, S. IF.4.
Nov. 25, 1913. Liddon, Capt. Matthew Robert

2, Westwood Road, Southampton.
June 26, 1917. Lindwall, Stanley

45, Madrid Road, Barnes, S.W.VS.
Mar. 24, 1914. Lloyd, Francis Wm.

85, Gracechurch Street, E.C.Z.

XIX

Date of Election.

June 11, 1918. Lock, Charles J.

E.M.S., 20, Hanover Square, W.l.
Dec. 23, 1913. Lock, Thos. Benjn.

78, Riggindale Road, Streatham, S.W.IQ.
Mar. 23, 1915. Longmire, J.

23, Furnival Street, E.CA.
Oct. 27, 1914. Loxton, Samuel E., F.R.A.S.

" Icknield," Little Aston, nr. Sutton Cold-
field.

May 25, 1883. Mainland, G. E., F.R.M.S.

14, The Norton, Tenby, South Wales.
June 27, 1916. Maitland, Ernest Augustus

96, Nihthwaite Boad, Wealdstone, Harrow.
Nov. 24, 1914. McTavish, Alex.

Cowley Grove Cottage, Uxbridge.
May 23, 1916. McEwen, Alfred

1118, Marhridge Building, Herald Square,
New York, U.S.A.
Nov. 26, 1912. Mardon, Daniel Arthur

Avon Cottage, Grange Boad, Bishops
Stortford.
Jan. 24, 1911. Marsh, George Robertson, M.A.

Mallards Close, Twyford, near Win-
chester, Hants,
Feb. 15, 1895. Marshall, William John, F.R.M.S.

15, Elms Boad, Dulwich Village, S.E. 21.
Nov. 28, 1916. Martin, John

The Laurels, 60, Culverdon Boad, Balham,
S.W.12.
May 18, 1906. Martin, William

" Kethlen," Burgh Heath, Epsom, Surrey.
Jan. 15, 1892. Maw, W. H., F.R.M.S., F.R.A.S.

18, Addison Boad, Kensington, W.14:.
Mar. 28, 1911. Maxwell, Edward Kelly, B.A.

H.M. Patent Office, W.C.2.
May 19, 1893. Merlin, A. A. C. EHot, F.R.M.S.

British Consulate, Volo, Greece.
May 22, 1917. Melhuish, F.

Nat. Debt Office, 32, London Wall, E.C.2.

XX

Date of Election.

July 2771877. Michael, A. D., F.L.S., F.Z.S., F.R.M.S.

The Warren, Studland, near Swaiiagey
Dorset.
Feb. 25, 1913. Mills, Fdk. Wm., F.R.M.S.

Thornleigh Edgerton, Hiuldersfield.
Jan. 20, 1905. Milne, William

70, Beech Grove Terrace, Aberdeen.
Oct. 18, 1901. Moore, Harry, F.R.M.S.

12, Whiston Grove, Moorgate, Rotherham,
Yorks.
July 26, 1878. Morland, Henry

Cranford, near Hounslow.
June 4, 1909. Mortimer, Hugh Hamilton

15, Mulgrave Road, Croydon.
Jan. 16, 1891. Muiron, C.

49, Chatsworth Road, Brondesbury,
N.W.2.
Nov. 22, 1910. Mummery, J. HoAvard, M.R.C.S.

79, Albert Bridge Road, Battersea, S.W.l 1 .
June 16, 1905. Myles, James Cellars

53, Carlyle Road, Manor Park, E.12.

Jan. 27, 1914. Nail, Rev. Geo. Herbert, M.A., F.R.M.S.

18, Deans Yard, Westminster, S.W.I.
Mar. 24, 1876. Nelson, E. M., F.R.M.S.

Beckington, Bath.
Feb. 15, 1907. Newman, Charles Arnold

Oundle, Northants.
May 27, 1913. Newmarch, Edgar Ribton

4, The Drive, Walthamstow, E.ll.
Jan. 26, 1872. Newton, E. T., F.R.S., F.G.S.

Florence House, 13, Willow Bridge Roady
Canonbury, N.\.
Feb. 12, 1918. Niblctt, Arthur Hem-y

Springfield House, Kcresley, nr. Coventry.
Jan. 17, 1908. Nicholson, Alfred

19, Victoria Road, Salisbury.
Nov. 28, 1916. Nicholson, Charles

Lansdowne House, Morley Street, Brad-
ford.

XXI

Date of Election.

June 23, 1914. Norman, Geoffrey

8, Cliffords Inn, E.CA.

Nov. 28, 1911. Nutt, Hy. Francis

51, Gurdon Road, Charlton, S.E.I,

Feb. 25, 1913. Oatley, Wm.

Badcox, Frome
Feb. 16, 1900. O'Donohoe, T. A.

8, Myrtle Road, Acton, Tf .3.
Jan. 24, 1879. Offord, J. M., F.R.M.S.

3, Cleveland Gardens, West Ealing, W.6,
Dec. 22, 1876. Ogilvy, C. P., F.L.S.

Sizewell House, Leiston, near Saxmund*
ham, Suffolk.
May 17, 1907. Ogilvy, J. Wilson, F.R.M.S.

18, Bloomshury Square, W.GA»
Nov. 15, 1907. Oke, Alfred William, B.A., LL.M.

32, Denmark Villas, Hove,
June 11, 1918. Oram, Ashley Edward

23, Goldhurst Terrace, S. Hampstead,
N.W.Q.
Nov. 18, 1892. Orfeur, Frank, F.R.M.S.

78, Avondale Road, South Croydon.
Dec. 27, 1867. Oxley, Frederick, F.R.M.S.

cjo A. E. Linton, Esq., Box 9, P.O.,
Nairobi, British East Africa. ■
Dec. 18, 1903. Oxley, F. J., M.R.C.S.

1, Dock Street, E.l,
Feb. 27, 1912. Palmer, Hy., J.P., F.R.G.S.

1, Pelaiv Terrace, Durham.
Nov. 25, 1913. Panichelli, Frank

7, Rowan Road, Hammersmith, W.Q.
April 10, 1910. Parfitt, Edward William

7, Gatcombe Road, Tujnell Park^ N.19.
Feb. 25, 1913. Parrott, Fdk. Wm.

" Morning side,'' Albert Road, Hale,
Cheshire.
Oct. 27, 1871. Parsons, F. A., F.R.M.S.

15, Osborne Road, Stroud Green, N.

XXll

Date of Election.

Dec. 16, 1904. Patterson, George

20, Madrid JRoad, Castle^mu, Barnes,
S.W.IS.
Jan. 18, 1901. Paulson, Robert, F.L.S., F.R.M.S.

" (r/ertrot/," Cecil Park, Pinner, Middlesex.
Oct 24. 1916. Penn, Charles Walter

80, Burhage Road, Heme Hill, S.E.24:.
May 20, 1904. Perks, Frederick John (Hon. Treasurer).

48, Grove Park, Denmark Hill, S.E,6.
Jan. 18, 1907. Perry, Francis Gough

2, The Cloisters, Gordon Square, W.C.I.
Dec. 11, 1917. Pike, Evan Vaughan

13, Mayola Road, Clapton, E.5.
Nov. 15, 1895. Pillischer, J., F.R.M.S.

88, New Bond Street, W.l.
April 25, 1910. Pinchin, Ernest Alfred, B.Sc.

4, Gleneldon Road, Streatham, S.W.IQ.
Jan. 15, 1904. Pledge, John H., F.R.M.S.

72, Nibthwaite Road, Harrow.
Nov. 23,- 1883. Plowman, T.

Nystuen Lodge, Bycullah Park, Enfield.
Sept. 21, 1894. Pollard, Jonathan, F.R.M.S.

10, Porteus Road, Paddington Green, W.2 .
June 21, 1895. Poulter, Christopher S.

Mount Lodge, Parkhurst Road, Bexley^
Kent.
May 17, 1901. Powell, David, M.A., F.R.M.S.

Over strand. Grove Park Road , CMswick,
If .4.
Dec. 20, 1907. Pratt, John Edwin

6, Heathfield Terrace, Seven Kings, Essex.
June 22, 1915. Price, Reginald A.

11a, Holland Road, Brixton, S.W.^.
Nov. 26, 1912. Pulford, Herbert, M.A., etc.

Broom Hill, Limpsfield, Surrey.

Nov. 6, 1908. Quick, Albert Hedley

** Inverness," Malvern Road, Thornton
Heath.

XXlll
Date of Election.

Jan. 18, 1901. Radley, Percy E., F.R.M.S.

Nesta, Broxbourne, Herts.
Nov. 25, 1913. Ramsay, Ernest Wm., P.A.S.I.

16, WhiteleyRoad, UpperNoi-wood,S.E.l9.
Mar. 28. 1916. Rasquin, Georges

46, Cunningham Park, Harrow-oyi-the-Hill.
Feb. 27, 1917. Read, Rev. Thomas

S. John's College i Batter sea, S.W,\\.
Feb. 27, 1917. Rendel, Alfred Barton, D.SC; F.R.S.

{President)

British Museum [Natural History), Crom-
well Road, S.W.I.
Mar. 20, 1896. Rheinberg, Julius, F.R.M.S.

2'^,The Avenue, Brondesbury Park, N ,W ,2,,
Mar. 23, 1915. Ribbons, Joseph Lovelace

" Greenhill,'" Reynolds Road, Beaconsfield,
Sept. 18, 1891. Richards, F. W.

104, *S'^. Luke Street, Montreal, Canada.
Oct. 2, 1908. Richards, William

" Poulters," Bentley, Hants.
Jan. 18, 1901. Richardson, John

28, Beaumont Avenue, Richmond, Surrey,
June 21, 1901. Robertson, Sir Helenus R., F.R.M.S.

Upton Grange, Chester.
Mar. 15, 1907. Robertson, James Alexander, F.R.M.S.

Sunnyside, Fleetwood.
Mar. 12, 1918. Robertson, W. J.

69, Bedford Road, Clapham, S.W.A.
April 28, 1914. Robotham, Fras. Edward

48, Lillieshall Road, Clapham, S.W.4.
May 23, 1916. Robins, Edmund Arthur

Swinton Lodge, Essex Road, Watford.
Nov. 13, 1917. Rodman, George Hook, M.D., F.R.P.S.

4:, Heath Mansions, Putney Heath, S. 1F.15.
June 4, 1909. Rolph, Frank

50, Ingatestone Rd., Woodford Green, E.l%.
Jan. 26, 1883. Rousselet, Charles F. [Vice-President and

Hon. Secretary for Foreign Correspondence)^
Curator R.M.S.

4, St. Matthew's Drive, S. Leonards-on-Sea,

XXIV
Date of Election.

Nov. 26, 1912. Row, Rd. Wm. Harold

36, Lexham Gardens, Kensington, IF. 8.
Nov. 18, 1904. Rowley, Frederick Richard, F.R.M.S.

8, Pinhoe Road, Heavitree, Exeter.
April 27, 1888. Russell, J.

16, Blacket Place, Newington, Edinburgh,

Mar. 24, 1914. St. George, Harry A.

112, Albany Street, Regent's Park, N.W.\ .
April 2, 1909. Saxton, Thomas R., A.M.I.C.E., F.R.M.S.

43, East Bank, Stamford Hill, AMG.
June 20, 1890. Scourfield, D. J., F.Z.S., F.R.M.S. {Vice-
President)

63, Queen's Road, Leytonstone, E.ll.
May 20, 1898. Sears, Robert S. W.

1, Lisson Grove, N.W.I.
Nov. 25, 1913. Shepherd, Benjamin

Fir Cottage, Oak Lane, Bounds Green,

N.n.

Dec. 28, 1909. Shephard, John

Clark Street, South Melbourne, Victoria.
June 21, 1907. Sheppard, Alfred William, F.R.M.S. {Hon.

Editor)

1, Vernon Chambers, W.C.X.
Jan. 28, 1913. Sheppard, Edwd. Jas., F.R.M.S.

137, Kennington Road, S.E. II.
Mar. 25, 1913. Shuckard, David Hy.

14, Walera7id Road, Lewisham, S.E. VS.
Feb. 28, 1911. Sidebottom, Henry

" Woodstock," Syddal Park, Bramliall,
Cheshire.
June 19, 1896. Sidwell, Clarence J. H., F.R.M.S. {Hon.

Curator)

46, Ashbourne Grove, Dulwich, S.E. 22.
Feb. 22, 1910. Simpson, Norman Douglas

Carlton Lodge, S, WellingtonRoad, Bourne-
mouth.
Oct. 21, 1904. Smith, Arthur Edgar

" Helios," 71, Fox Lane, Palmer's Green,
A.13.

XXV
Date of Election.

-April 24, 1917. Smith, Charles Howard

59, Nelsoyi Road, Stroud Green, N.
Mar. 25, 1870. Smith, F. L.

49, Belvedere Road, Upper Norwood,
S.E.l^.
Mar. 17, 1899. Smith, Frank P.

2, King's Villas, Chase Road, Southgate,
i\M4.
Mar. 17, 1905. Smith, Frederick

13, Rye Hill Park, Peckham Rye,
S.E.15.
Mar. 28, 1916. Smith, Herbert Havet

6, Preston Road, W est clifj -on-Sea.
-Nov. 18, 1898. Smith, Thomas J., F.R.M.S.

c/o W, Watson dh So7is, 313, High Hoi-
born, T'F.C.l.
Jan. 15, 1892. Soar, C. D., F.L.S., F.R.M.S.

37, Dryhurgh Road, Putney, /S'.Tf .15.
Feb. 23, 1915. SoUis, Wm. Powell
April 24, 1917. Sonntag, Charles Frederick

126, Great Portland Street, W.\.
April 21, 1899. Spitta, Edmund J., L.R.C.P., M.R.C.S.,

F.R.A.S., F.R.M.S.

41, Ventnor Villas, Hove, Brighton,
-^an. 15, 1904. Sprague, T. B., LL.D.

1^65^ Holme, Woldingham, Surrey.
-Jan. 28, 1913. Spry, Lt. Robt., R.N., F.R.M.S.

83, Mount Gold Road, Plymouth.
Jan. 18, 1907. Stahl, Arthur

1], Scotts Avenue, Shortlands, Kent.
* Jan. 25, 1916. Stephanides, Theodore
:Nov. 27, 1885. Stevenson, G. T.

Ravenscourt, Haling Park Road, South
Croydon.
June 18, 1897. Still, Arthur L.

Roslyn, Dower Avenue, Wallington.
-Nov. 16, 1894. Stokes, William B.

212, N^otre Dame Street, West Montreal.
^Jan. 23, .1917. Stow, Albert Archie

The Croft, New Maiden, Surrey.

XXVI

Date of Election.

Oct. 24, 1916. Stringer, Edward Belcher

Egerton Lodge ^ Bromley , Kent.
Dec. 15, 1893. Sturt, Gerald

" Lisynore," Cavendish Road, Weyhridge^.
Dec. 17, 1875. Swift, M. J., F.R.M.S.

Q,Aylestone Avenue^ Brondesbury, N. W.Q..
Dec. 28, 1915. Syer, John

Stanmore Hill, Middlesex.

Nov. 28, 1879. Taskcr, J. G.

30, Junction Boad, Upper Holloivay, AM 9^
Oct. 16, 1896. Taverner, Henry, F.R.M.S.

319, Seven Sisters Boad, Finshuru,
Park, NA.
Feb. 17, 1905. Taylor, Thomas George

Ballaclague, Ellington Park Boad, Bams-
gate.
TJar. 28, 1916. Tennant, John, M.A.

19, TheBoltons, .S'.IIMO.
?,:ar. 28, 1916. Terry, Henry Clarke

"Colling wood,'' Kenwyn Street, Harslville^,
N.S.W.
Dec. 22, 1865. Terry, John

8, Hopton Boad, Streaiham, S.W.liy,
Feb. 12, 1918. Thomas, Benjamin John

70, Belleville Boad, Wandsworth Common^

s.w.u.

Mar. 28, 1916. Thomas, Reginald Walter

15, Ambrose Avenue,Golders Green, N .W A
June 26, 1917. Thomas, Robert Herbert

174, St. Leonards Boad, East Sheen,^
S.WA^.
June 24, 1913. Tierney, Clarence U. S., B.Sc, F.R.M.S.

*' Netherton," Coulsdon, Surrey.
May 16, 1902. Tilling, George, F.R.M.S.

" Gras7nere," Bydal Boad, Streatham,.
S.W.XQ.
Nov. 25, 1913. Tilling, Wm. Geo.

20, Streathbourne Boad, Upper I'ooiingy.
S.W.M.

XXVll

Date of Election.

Nov. 24, 1914. Tindall, Wm. B.

39, St. Mary Street, Toronto, Canada.
April 9, 1918. Tipping, William Moore

Bryn Pabo, near Llandudno,
June 11, 1918. Titchener, George Richard

10, Dalherg Road, Brixton, S.W.2.
Jan. 25, 1910. Todd, Charles Stephen

25, Hanover Road, Tottenham, N.17.
Feb. 27, 1912. Tomlinson, Edwd. Theodore

8, St, George's Square, S.W.I.
April 25, 1916. Topsent, Prof. Emile

Faculte des Sciences Dijon {Cote d'or)^
France.
Dec. 21, 1894. Traviss, Will. R.

42, Winchester Avenue j Brondeshury^
iV.IF.6.
A^ov. 13, 1917. Trist, Arthur Ronald

" Birchfield,'' Aldenham Road, Bushey..
Feb. 25, 1913. Trotman, Alex. Chas.

28, Guhyon Avenue, Heme Hill, S.E.24:.
Mar. 5, 1909. Troughton, Henry George

3, New Court, Lincoln's Inn, W.C.2.
June 17, 1892. Turner, C.

20, Minster Road, CricUeivoodj N.W.2.
May 25, 1915. Tutt, John Francis Donald, F.R.C.V.S.

'' Rothiemurchus," St. Cross, Winchester,
Feb. 25, 1913. Tyas, Rev. Vetranio

12, Felsfead Road, Wanstead, E.ll.

April 9, 1918. Vickery, Ernest James

33, High Street, Budleigh Salterton^
Devon .
July 25, 1873. Walker, J. S.

6, Warwick Road, Upper Clapton, E,^^
June 26, 1917. Waller, William Thomas

Bingham House, Richmond, Surrey.
Mar. 27, 1917. Wallis, Thomas Edward 4

5, Hillsborough Avenue, Exeter,
Nov. 22, 1910. Watts, Geo. W.

103, Haverstock HilL N.W.3.

XXVlll
Date of Election.

Mar. 20, 1908. West, Joshua Cobbett

''Holly Cottage," Chvrch Street, Sunbury-
on-Thames.
Feb. 25, 1876. Wheeler, George
Jan. 25, 1910. Whitehead, Henry, B.Sc. Lond.

23, Downie Terrace, Murray field, Edin-
burgh.
Nov. 2e>, 1912. Whitteron, Fred.

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Victoria,
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Eversley, Uttoxeter.
Nov. 23, 1877. Williams, G. S.

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XXIX

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K.C.V.O.
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XXX

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List of Exchanges and of Societies, etc., which

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XXXI

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Natural History Society of Northumberland, Durham, and
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xxxu

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XXXlll

Victoria, Australia, Field Naturalists' Club of. A. D. Hardy,
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JouRN. Q. M. C, Series II.— No. 83 36

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MBL WHOI LIBRARY

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