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THE JOURNAL OF

THE POSTAL MICROSCOPICAL SOCIETY.

E6ltor :

ALFRED ALLEN,

Bon. Sec. P.M.S. ;
WITH SEVERAL ASSOCIATE EDITORS.

VOL VI. THIRD SERIES.
VOL. XV. OLD SERIES.

BAILLIERE, TINDALL, & COX, 20 & 21 KING WILLIAM ST, STRAND.

Bristol :

JOHN WRIGHT & COMPANY, STONE BRIDGE.

1896.

BATH :

C. SEERS AND SON, PRINTERS, 2 ARGYLE ST.

V'Yef

ace.

-o-

^^CCORDING to our usual custom, we feel impelled
\^j[ to write a few words concerning the volume, which
forms Vol. VI. of the Third Series of the International
Jourrial of Alicroscopy and Natural Science^ just finished.

The standard of excellence to which the Journal has
attained during the last few years has, we believe, been well
kept up in the present volume. As so many papers of scien-
tific value have appeared in its pages, we hardly know which to
mention without giving the whole list ; but we must certainly
point to the series of papers on " British Hydrachnidae," by
Mr. Chas. D. Soar, as being of the greatest service to those of
our readers who are interested in this subject. Among other
papers of interest we must mention our late President, Mr.
Bryan's, account of Prof. Miall's researches on " The Origin of
Insect Transformations," Mr. W. Falconer's article on " Some
Adaptation of Water-Plants to their Environment," Messrs.
Wager and Walker's paper " On the Structure of the Root,"
Miss Lily H. Huie's paper "On some Protein Crystalloids, etc.,"
Mr. C. D. Hardcastle's article on " The Origin and History of
Varieties of Agate," etc. " On Limnaea Peregra," by Mr. W.
Nelson ; the continuation of Mr. H. C. A. Vine's memoir on
the " Predacious and Parasitic Enemies of Aphides," etc. ;
Messrs. Hoole and Harrow's article on " Some Notes on the

IV. PREFACE.

Victoria Regia," must also be included in our list, besides many
minor articles and abstracts from other scientific journals.

At the request of many members of the Postal Microscopi-
cal Society, we have published a number of Notes from the
Society's Note-Books. From communications received, we are
glad to hear that this has given great satisfaction to our readers.
The Notes of Methods of Technique which we have given
during the past year have also been much appreciated. We
may also mention that the memoirs by Dr. Vicentini on the
" Bacteria of the Sputa and Gryptogamic Flora of the Mouth "
have been reprinted, and we hope to issue them shortly in
book-form. Prof. W. D. Miller, of Berlin, has kindly written
the preface to Dr. Vicentini's book.

We cannot conclude our remarks without expressing the
hope that our readers will derive as much pleasure and profit
from the present volume as they have from those which pre-
ceded it.

^N^XX3^

THE INTERNATIONAL

JOURNAL OF MICROSCOPY & NATURAL SCIENCE :

THE JOURNAL OF THE POSTAL MICROSCOPICAL SOCIETY.

'■'■Knowledge is not given us to keep, but to impart ; its worth
is lost in concealment."

[The Editor does not hold himself responsible for the views of
the authors of the papers published.]

prc0i^entlal H^^re00.

By R. H. Moore.

^alfe^ "~ ;

N taking the Presidential Chair this evening, it is

-sj-"

1

after a twelve months' dream as to why I was
selected for it. My first tableau was a mild
growl with my excellent friend, the Founder and
Honorary Secretary of the Society, for recom-
mending me to the position ; however, his gentle-
ness and courtesy soon dispersed my wrath. My
second vista was one of perplexity and mental
torture as to what I should say when I reached
this chair. Official and municipal duties in my native city, "The
Queen of the West," have prevented me for several years from
actively prosecuting microscopical studies. My third vision was
a pleasant retrospect of twenty-two years' connection with a valu-
able Society and reflections of many hours of delight in writing
in its books, preparing slides, and illustrating them, during the
first half of its existence ; whilst my fourth phantom was of a
pleasant gathering now realised, when members, in great part
unknown to each other, should meet for good cheer and to
encourage our Honorary Secretary.

1 have discovered nothing new in microscopical science, I am

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. - b

2 • PRESIDENTIAL ADDRESS.

not now in any way adding to scientific knowledge ; yet, I am as
ready as ever to encourage a Society which fills an honoured place
in microscopical researches.

On looking over the last published list of the members, I find
that only six of us remain who united in starting the Society, and
perhaps one of the reasons for which I occupy the chair to-night
has been your desire to confer this great honour upon one who
has never deserted it, and who has no inclination to do so.

The Value

of this Society has really never been questioned. We have had
our critics through the twenty-two years of its history, some wise
and some otherwise, but it holds the unique position of affording
scientific instruction and recreation in the home. The wives,
children, friends [and maidservants. — Ed.*], of some of our past
and present members, have shared many pleasurable evenings
through its agency in the enjoyment of microscopical pursuits. In
scientific societies ladies and children are usually rigidly excluded,
the husband and father must enjoy his scientific researches under
Club rule. He is either missed or dismissed from the drawing-
room to indulge in them. We possess the privilege of selecting
our days and hours of study under the fascinating, although rather
hackneyed term of " Home Rule." Our esteemed Honorary Sec-
retary, in his address to you last year, referred to the utility of the
Society in the inspiration it has given to its members to form local
societies. True, we may have lost some members by this praise-
worthy enterprise, but there is satisfaction in knowing that our
work is carried on with no desire to merely benefit ourselves. If
our roll of membership has been weakened, or some have not
been added to it through the formation of local Societies, we have
the compensation of a harvest of men and women who have been
led into scientific studies from the seeds which have been scattered
by our own institution. We possess the one great advantage of

* In one of our earlier note-books a member relates his experience some-
what as follows : — After an evening spent in examining one of our boxes, he
left his microscope with the J-inch objective attached, and sundry slides on his
study-table, and was much annoyed in the morning to find one of the slides
smashed and the ^-"ich objective totally destroyed. On enquiry he learned
that his maidservant had been doing her microscopy before breakfast !

PRESIDENTIAL ADDRESS. 3

cultivating scientific researches in the areas lying between towns
and cities, where, through paucity of population, scientific societies
cannot be maintained. We urge, therefore, the claims of the
Society on the microscopists of our cities and towns, not so much
for the sake of their own erudition, but we need their experience
and help for the benefit of other students of the microscope who
have less advantages, and to whom, if I may quote from a well-
known advertisement, this Society comes " as a boon and a
blessing to men." This great advantage can never materially
lessen from the keen scientific competition of the age, because
this Society supplements a want beyond its reach. Therein are
the elements of growth and prosperity, and we strongly appeal to
microscopists in our larger towns to co-operate with us in render-
ing the Society attractive and of distinguished value to those who
may become members from the rural districts.

During the last few years we have lost members who were real
workers in special subjects in the microscopical world. Their
slides, and the note-books which accompanied them, were especially
valuable. I am afraid, from what our Secretary tells me, that this
loss is still going on. I would strongly urge on those who remain
to us, and who are noted for excellent work, to continue that work
for the benefit of those who, if less experienced, are not less ardent
in their love of microscopical science, and who deserve every
encouragement from the more experienced members.

The Work

of the Society has passed through many phases, and thanks to our
enterprising Honorary Secretary, his fertile brain has often evolved
new schemes for attracting scientific pursuits. Boxes of single
miscellaneous slides have been supplemented by those of series
slides, where members contribute the whole of the contents, and
are able to write in and illustrate the note-books in a truly educa-
tional spirit. Sections have been formed especially for pathological
and botanical study, and if they have not succeeded to the extent
that was desired, the experiment was valuable in ascertaining the
need or otherwise of such a particular branch of study. Since my
selection to fill the chair to-night, I have been careful to note the
quality of the contributions which have been circulated during the

4 PRESIDENTIAL ADDRESS.

past twelve months, and I am pleased to testify to their great
value. One member, Mr. Bostock, has contributed valuable slides
and information in regard to the Oribatidce. Dr. Walker sent
round some well-mounted, double-stained slides of stems, buds,
and roots, which were well illustrated and described. He has also
added to our information by a series of Odontophores. Mr. Neeve
circulated a box of Marine Algae, illustrated by dried and mounted
specimens and notes ; followed by a second series, with highly
finished drawings from the pencil of Miss Phillips. Mr. Bassano
has favoured the Society with botanical and entomological objects;
Dr. Bossey, Mr. Dawson, and the Rev. A. C. Smith, have aided
us by well-mounted specimens of Diatomacefe. Messrs. Beards-
more, Fisher, and several others, have done excellent work in the
botanical division of microscopical science.

In examining the slides and reading the notes of these and
other members who have so usefully served the Society, I am
painfully reminded of my own short-comings, and perhaps our
Honorary Secretary is rejoicing that he has helped to place me in
a position where I am compelled to act the part of a penitent. If
there are any other members of this Society who share my feelings
to-night, we had better atone for the past by a pious resolve here
and now to alter our ways. I may add, however, that if, during
the last few years, I have not been a worker, I assuredly have not
been a critic of the contributions of my fellow members. You
will not find in the note books any complaints of my own that
boxes are not up to the average, slides are not well finished, and
notes are sparse. I have profited by the remarks of our Secretary
that those members who complain of few notes are usually those
who never add any. In thinking over our Work, I believe the
Honorary Secretary will be glad to receive, not only series slides,
but boxes which contain slides of a series character confined to a
particular plant or insect. While there may be nothing new in
objects comprised in the three kingdoms of nature, their respec-
tive types having been so earnestly studied, there yet remains
much of novelty to be disclosed by patient observation of particular
parts of structure. I well remember in earlier years contributing
boxes of slides and notes and drawings, which perhaps I may be
permitted to describe as " monographs."

PRESIDENTIAL ADDRESS. O

I was particularly interested in the microscopical details of
what are called " common objects " lying all around us. The
Senecio vulgaris (Groundsel), the Linaria Cymbalaria (Ivy-leaved
Toad-flax), the Anogallis arvensis (Scarlet Pimpernel), afforded me
hours and days of interesting study. I found no existing literature
which described their microscopical details, and so I was obliged
to examine them patiently and carefully before I could write about
them. Had opportunity offered, I should have been delighted to
pursue similar investigations, for I know of no more fascinating
employment for needle, scalpel, and lens, than to prepare and
chronicle the hidden beauties of "the commonest objects which He
around us. That which I attempted in the field of Botany equally
applies to the region of Entomology. If some of our members
could be induced to take up such studies in the new year we enter
upon to-night, I am confident that their " monographs " would be
attractive and instructive, and that many of them will find their
way into the pages of our Journal because of their real value. I
w'ould also suggest that Animal Parasites offer another field for
excellent study, and that they will furnish slides and notes of
attractive and instructive character. Since my contributions, as
stated before, I was deeply interested in Parasites, as to the variety
of form and of appendages, their limb structure so adapted to
their habits, and especially as to their frequent rudimentary organs.
I commenced a box of slides, with note book and drawings to
illustrate a dozen specimens, but, alas !

" Art is long, and Time is fleeting."
They still lie in my study drawer, incompleted, and filling my heart
every now and then with a fond regret. I shall, however, use my
best endeavours in the coming winter to resume my studies, and
employ some of its hours, if possible, in actively helping our
Society. In speaking of work, I am sure it would be interesting
to all of us if our members would search their own particular
districts for microscopical objects. For example, in my own native
city the Mineral Waters of Bath are the habitat of the Fresh
Water Alga, Oscillatoria tenuisstma, which, according to Harvey,
is only to be found in those celebrated warm waters. Specimens
and illustrations of such native subjects would, if circulated among
our members, be instructive and beneficial to all.

6 PRESIDENTIAL ADDRESS.

Having sketched the value of the Work of our Society, let me
dwell for a few moments on its

Prospects,
and I see every reason for encouragement, and not one for despair.
It is too true that we want more members to fill the places of those
who have resigned, or who have been lost to us by death. It is
also true that in our centres of industry many of our older Scien-
tific Societies, in this competitive age, are languishing, if they
have not already died out, but as I have before stated this Postal
Microscopical Society holds a unique position. She is a fairy
visitor to our homes. We never want to go abroad to find her.
She interests our wives and children, and under our own lamp-
shade and by our own fireside we can pursue our microscopical
studies. Wonderfully convenient as well as valuable. For this
reason we ought to be able to increase our membership year after
year, and with good slides, full notes, and copious drawings, suc-
cess will be assured. While we use every effort to retain our
members who are in the midst of city and town life with all its
advantages, we ought to make a special effort to secure new mem-
bers from our rural districts, where men and women are engaged
in microscopical pursuits under many disadvantages. May I ven-
ture to hint that a short but a striking occasional advertisement in
one or more of our popular scientific and technical journals would
be desirable ? I do not now see the weekly English Mechanic, but
a few years ago its pages were often enriched by excellent micro-
scopical chapters, proving that a large portion of its readers must
have been interested in Microscopy. If they are still continued,
would not an occasional advertisement of our Society bring us
some new working members ?

Would it not be possible to circulate boxes with notes, at occa-
sional intervals, confined to the subjects of dry, balsam, and fluid
mounting of slides ? How to prepare vegetable and animal tissues,
so as to procure a better knowledge of histology. We might take
advantage of the rapid progress of Technical Education. The
classes now in full operation, under the management of our County
Councils, will undoubtedly cultivate all branches of Science, and
Microscopy will have its share of attractions among the artizans
and middle classes of our land. My own experience is, that for

PRESIDENTIAL ADDRESS, 7

a long time past some of our best microscopical work has been
achieved by men who hold aloof from our Societies on the ground
that the Societies are too learned or too respectable. I believe
that this Society can offer great advantages to an influx of students
belonging to our Technical Schools, if its objects are better known.
A question would probably arise as to a lower rate of subscription,
and a membership with or without an obligation to subscribe to
the Journal, but this part of the subject could be discussed and a
scheme evolved by the enterprise of our Honorary Secretary. My
one aim is to assist workers in microscopical studies. I have no
desire to reduce the intellectual and scientific status of this Society,
and to enrol anybody and everybody who chose to apply for
admission. I cannot, however, close my eyes to the fact that
students from our elementary schools are passing in large numbers
to the science classes which have been formed, and their studies
will create a demand for such a Society as our own.

In reference to our prospects, I am anxious that our heartiest
support should be given to our Honorary Secretary in the enterprise
he shows in connection with the Postal Microscopical Journal. It
must be a very heavy tax on his time and resources. If we com-
pare the recent volumes with those of earlier date, the growing
excellence of the Journal is apparent to every one of us. Its
high-class papers and elaborate illustrations deserve the support of
all of us. If it were possible for him to impart only a small por-
tion of his energy into the minds of his readers we should very
soon obtain an extended list of subscribers.

I deeply regret that your President is one wholly unable to
enrich you with the researches of an ardent student of Micro-
scopical Science. He is far too respectful to his fellow members
to indulge in a resume of Microscopical researches, up to date,
culled from the several Journals which are at their own command.
He has been contented to review the past, study the present, and
to offer a few words of encouragement and stimulus, so that the
future of this Society may be prosperous and progressive.

[ 8 ]

lEypeinmcntal iSvolutton ainonget Iplants/

By L. H. Bailey.

DE VARIGNY has written a most suggestive book upon
Experimental Evolution, in which he contends for the
establishment of an institution where experiments can be
definitely undertaken for the purpose of transforming a species
into a new species. " In experimental Iransformism," he writes,
" lies the only test which we can apply to the evolutionary theory.
We must use all the methods we are acquainted with, and also
those, yet unknown, which cannot fail to disclose themselves
when we begin a thorough investigation of the matter, and do our
utmost to bring about the transmutation of any species. We do
not specially desire to transform any one species into another known
at present ; we wish to transform it into a new species. .
Experimental transformism is what we need now, and therein lies
the only method we can use."

This is a most commendable object, and I hope that the
attempt will be made to create a new species before our very eyes.
This is what most people demand as a proof of evolution, and
they are sometimes impatient that it has not been done ; and it
would seem, upon the face of it, that nothing more could be
desired. When I reflect, however, upon the fact that this very
thing has occurred time and again with the horticulturist, and
consider that botanists and philosophers persist in refusing to see
it, I am constrained to offer some suggestions upon De Varigny's
excellent ambition. If I show a botanist a horticultural type of
recent or even contemporaneous origin, which I consider to be
specifically distinct from its ancestors, he at once exclaims that it
is not a species, but a horticultural variety. If I ask him why, he
replies, " Because it is an artificial production ! " If I show him
that the type is just as distinct from the species from which it
sprung as that species is from its related species, and that it repro-
duces its kind with just as much certainty, he still replies that,
because it is a horticultural production, it cannot be a species,

* Abstract of an Address before the Massachusetts Horticultural Society,
Boston, Feb. 23, 1895, in The American Naturalist.

EXPERIMENTAL EVOLUTION AMONGST PLANTS. 9

In what, then, does an accidental horticultural origin differ from
any other origin ? Simply in the fact that one takes place under
the eye of man, and the other occurs somewhere else ! It is
impossible, at the present day, to make a definition of a species
which shall exclude many horticultural types, unless an arbitrary ex-
ception is made of them. The old definitions assumed that species
are special creative acts, and the method of origin is therefore stated
or implied in all of them. The definition itself, therefore, was
essentially a statement of the impossibility of evolution. We have
now revised our definitions so as to exclude the matter of origin,
and thereby allow free course to evolution studies ; and yet here
is a great class of natural objects which is practically eliminated
from our consideration because, unhappily, we know whence the
forms came ! Or, to state the case differently, these types cannot
be accepted as proofs of the transformation of species because we
know certainly that they are the result of transformation !

Now, just this state of things would be sure to occur if De
Varigny were to transform one species into another. People would
say that the new form is not really a species, because it is the
result of cultivation, domestication, and definite breeding by man.
He could never hope to secure more remarkable transformations
than have occurred a thousand times in the garden ; and his
scheme — so far as it applies to plants —is essentially that followed
by all good gardeners. Or, if the prejudices of critics respecting
the so-called artificial production of species could be overcome,
he could just as well draw his proofs of evolution from what has
already been done with cultivated plants and domesticated animals,
as from similar results which might arise in the future from his
independent efforts. I am not arguing against the scheme to
create a species before our eyes, but I am simply stating what has
been and is the insurmountable difficulty in just this line of
endeavour — the inability of the experimentor to satisfy some scien-
tific men that he has really produced a species; for it is a singular
thing that, whilst all biologists now agree in defining a species upon
its tangible and present characters, many of them nevertheless act
upon the old notion that a species must have its origin somewhere
beyond the domain of exact history.

This notion that a species, to be a species, must have origi-

10 EXPERIMENTAL EVOLUTION

nated in nature's garden and not in man's^ has been left over to
us from the last generation — it is the inheritance of an acquired
character. John Ray, towards the close of the seventeenth cen-
tury, appears to have been the first to use the word species in its
technical natural history sense, and the matter of origin was an
important factor in his conception of what a species is. Linnaeus'
phrase is familiar: "We reckon as many species as there were
forms created in the beginning." Darwin elaborated the new con-
ception— that a species is simply a congregation of individuals
which are more like each other than they are like any other con-
gregation— and with a freedom from prejudice which is rarely
attained even by his most devoted adherents, he declared that
" one new variety raised by man will be a more important and
interesting subject for study than one more species added to the
infinitude of already recorded species. The old naturalists threw
the origin of the species back beyond known causes ; Darwin
endeavoured to discover the "Origin of Species," and it is signifi-
cant that he set out without giving any definition of what a species
is. I have said this much for the purpose of showing that it is
important, when we demand that a new species be created as a
proof of evolution, that we are ourselves open to the conviction
that the thing can be done.

I have said that no modern naturalist would define a species
in such terms that some horticultural types could be excluded,
even if he desired that they should be omitted. Haeckel's excel-
lent definition admits many of them. In his view, the word
species " serves as the common designation of all individual
animals or plants, which are equal in all essential matters of form,
and are only distinguished by quite subordinate characters." It is
impossible, however, to actually determine, if one has a species
in hand, by applying a definition. One must show that his new
type — if it is a plant — has botanical characters as well marked as
similar accepted species have ; and these characters must show,
as a whole, a general tendency towards permanency when the
plant is normally propagated by seeds. He must measure his
type by the rule of accepted botanical practice. If the same plant
were found wild, so that all prejudice might be removed, would
the botanist unhesitatingly describe it as a new species ? If yes,

AMONGST PLANTS. 11

then we should say that a new species had been created under the
hand of man ; and this rule I wish now to apply to a very few
familiar plants. In doing so, I do not wish to be understood as
saying that I consider it advisable to describe these plants as
species under the existing methods of botanical description and
nomenclature, for, merely as a matter of convenience and perspi-
cuity, I do not ; but I wish to show that they really are, in every
essential character, just as much species as very many other
universally accepted species are.

[The speaker then produced numerous instances of the evolu-
tion of forms of garden plants, in various genera, which are as
distinct from their parents, and from each other, as accepted
species of the same genus are; and these forms are as permanent,
when multiplied extensively through many years by means of the
seeds, as these wild species are. " Here we have absolutely new
and unique types, as De Varigny demands, and they are as distinct
from each other and from their parents, in accepted botanical
characters, as ' good species ' in the same genus are from each
other, and they perpetuate these characters as unequivocally as
those species do. Moreover, we know definitely what their origins
were, and they therefore answer all the purposes of experimental
evolution.

" All this is but another illustration of how tenaciously botan-
ists still hold to the Linnaean idea of species, whilst they profess
the Darwinian idea."]

I have now brought to your attention a few familiar plants for
the purpose of showing that what are, to all intents and purposes,
good species have originated in recent years ; and that, whilst
Botanists demand that the origination of species within historic
times shall constitute the only indisputable proof of organic evo-
lution, they nevertheless refuse to accept as species those forms
which have thus originated, and which answer every demand of
their definitions and practice. The proofs of the evolution of
species, drawn from the accepted practice of the best botanists
themselves, could be indefinitely extended. We need only recall
the botanical confusion in which most cultivated plants now lie, to
find abundant proof of the evolution of hundreds of types so
distinct that the best botanists have considered them to be species;

12 EXPERIMENTAL EVOLUTION

but other botanists, basing their estimate of species upon origins,
have reduced them or reincluded them into the form or type first
described. Consider the number of species which have been
made in the genus Citrus, comprising the various oranges, lemons,
limes, and the like. Recall the roses. The moss-rose and others
would be regarded as distinct species by any botanist if they were
found wild, and if they held their characters as tenaciously as they
do under cultivation. In fact, the moss-rose was long regarded as
a good species, and it was only when its origin began to be under-
stood that this opinion was given up. The earlier botanists, who
were less critical about origins than the present botanists are, made
species largely upon apparent features of plants, although their
fundamental conception of a species was one which was created,
as we find it, in the beginning. Yet, strangely enough, we at the
present day profess to regard species as nothing more than loose
and conventional aggregations of similar individuals, and which
we conceive to have sprung from a common ancestor at some
more or less late epoch in the world's history, — we make our
species upon premises which we deny, by giving greater weight to
obscurity of origin than we do to similarities of individuals.

The fact is that much of the practice of systematic or descrip-
tive botany is at variance with the teachings of evolution. Every
naturalist now knows that nature does not set out to make
species. She makes a multitude of forms which we, merely
for purposes of convenience in classifying our knowledge of
them, combine into more or less marked aggregations, to
which we have given the name species. Now and then
we find in nature an aggregation of successive individuals,
which is so well marked and set off from its associated groups,
that we think nature to have made an out-and-out distinct
species ; but a closer acquaintance with such species shows that
in many cases, the intermediate or outlying forms have been lost,
and that the type which we now know is the remainder in a contin-
uous problem of subtraction. In other cases, it appears to have
arisen, without intermediate forms, as a distinct offshoot from an
older type. This is well illustrated in many remarkably distinct
garden forms, which originated all at once with characters new to
the species or even to the genus. I have mentioned such a case

AMONGST PLANTS. 13

in the Upright tomato. Even the sudden appearance of these
strange forms is proof that species may originate at any time, and
that it can be no part of our fundamental conception of a species
that it shall have originated in some remote epoch. Species-
niaking forever enforces the idea of the distinctness and immuta-
bility of organic forms, but study of organisms themselves forever
enforces an opposite conception. The intermediate and variable
forms are perplexities to one who attempts to describe species as
so many entities which have distinct and personal attributes. So
the garden has always been the bugbear of the botanist. Even
our lamented Asa Gray declared that the modern garden roses are
'• too much mixed by crossing and changed by variation to be
subjects of botanical study." He meant to say that the roses are
too much modified to allow of species-making. The despair of
systematic botanists is the proof of evolution !

I repeat that mere species-making, in the old or conventional
sense, is an incubus to the study of nature. One who now de-
scribes a species should feel that he is simply describing a variable
.and plastic group of individuals for mere convenience' sake. He
should not attempt to draw the boundary lines hard and fast, nor
should he be annoyed if he is obliged to modify his description
every year. This loose group may contain some forms which
seem to be aberrant to the idea which he has in mind ; and il
would seem as if he should be ready to call them new or distinct
species whenever, from whatever cause, they become so much
modified that it is convenient, for purposes of identification and
description, to separate them from the general type. Just as soon
as botanists come to feel that all so-called species of plants are
transitory and artificial groups maintained for convenience in the
study of nature, they will not ask whether they are modified out-
side the garden or inside it, but will consider groups of equal
distinctness and permanence to be of equal value in the classifi-
cation of knowledge, wholly aside from the mere place of their
origin. At the present time, the garden fence is the only distinc-
tion between many accepted species and many discarded ones.
The cultivation of man differs from the methods of nature only in
degree, not in kind; and if man secures results sooner than nature
does, it is only another and indubitable proof of the evolution of

14 EXPERIMENTAL EVOLUTION AMONGST PLANTS.

organic forms. It is certainly a wholly unscientific attitude to
demand that forms originating by one of nature's methods are
species, while similar forms originating by another method are
beneath notice.

If species are not original entities in nature, then it is useless
to quarrel over the origination of them by experiment. All we
want to know, as a proof of evolution, is whether plants and
animals can become profoundly modified under different con-
ditions, and if these modifications tend to persist. Every man
before me knows, as a matter of common observation and practice,
that this is true of plants. He knows that varieties with the most
marked features are passing before him like a moving panorama.
He knows that nearly every plant, which has been long cultivated,
has become so profoundly and irrevocably modified that people
are disputing as to what wild species it came from. Consider that
we cannot certainly identify the original species of the apple,
peach, plum, cherry, orange, lemon, wine grape, sweet potato,
Indian corn,, melon, bean, pumpkin, wheat, tobacco, chrysanthe-
mum, and nearly or quite a hundred other common cultivated
plants. It is immaterial whether they are called species or varieties.
They are new forms. Some of them are so distinct that they
have been regarded as belonging to distinct genera. Here is the
experiment to prove that evolution is true, worked out upon a
scale and with a definiteness of detail which the boldest experi-
menter could not hope to attain, were he to live a thousand
years. The Horticulturist is the only man in the world whose
distinct business and profession is evolution. He, of all other
men, has the experimental proof that species come and go.

It is stated that Prof. Carl Barus has constructed a new top
for educational purposes. The " peg " of the top consists of a
writing stylus, adapted to pencil a graphite record of its motions
upon a slate or sheet of paper. The motion of the " peg " simu-
lates the motion of procession about a moving axis, which, in its
turn, is in both rotational and translational motion. The complex
spiral and cycloidal curves which may be thus obtained present an
exceedingly beautiful appearance.

[ 15 ]

Zbc jfiyation of ll^crve jfibrca b^ fformalin/

By Edwin M. Kitchell, M.D.

WITH the exception of osmic acid, the older fixatives do
not preserve without considerable shrinkage of the axis
cylinder of the nerve fibre ; therefore, as formalin has,
in my hands, given excellent results in the preservation of the
axis cylinder, and as its effects on the myelin are also rather inter-
esting, I have thought that it might be useful to publish a note on
the subject.

The tissues used in my experiments were pieces of the sciatic
nerves of the dog and of the rabbit, cut through their entire
thickness. Even with pieces of tissue of this size, formalin pene-
trates and fixes the fibres throughout the nerve. I used one, two,
ten, twenty-five, fifty, and a hundred per cent, of the commercial
solution.!

In the specimens treated with one and two per cent, formalin,
the axis cylinder and myelin were both shrunken, as they would
be by alcohol, for example. Ten per cent, causes less shrinkage
than two per cent, but is still unsatisfactory. In the specimens
fixed in twenty-five, fifty, and a hundred per cent, the axis cylin-
der remains entirely or almost unbroken in the majority of the
fibres. The results were rather better with formalin of full
strength. The diameter of the unshrunken axis cylinders, under
these circumstances, is about 0*5 to o*8 of that of the entire fibre.

I tried staining the nerve fibres fixed in 'formalin with acid
fuchsine, eosine, and other aniline dyes ; also Gage's haematoxylin,
(over-staining). All these colour the connective tissue strongly
while the unshrunken axis cylinder is but lightly stained. I
thought Gage's hsematoxylin rather the best. Axis cylinders, on
the other hand, which are considerably shrunken, are readily
stained by these dyes. This may, perhaps, be explained by the
concentration of the material taking the stain in a smaller space,
which is the case when the axis cylinder is shrunken.

Transverse sections of the fibres in twenty-five to one hundred

* From The New York Medical Journal, July 20th, 1895.
t This is a forty per cent, aqueous solution of formaldehyde.

16 THE FIXATION OF NERVE FIBRES.

per cent, formalin solution show numerous little lines which run
through the myelin in an irregularly radial direction. When viewed
longitudinally, the appearance is that of a fine network, the so-
called neurokeratin network.

This network is much more distinct and regular than that seen
in the myelin of nerve fibres, which, for example, are fixed in
Mliller's fluid. It is w^ell shown by staining with Weigert's
haematoxylin, or with iron-alum haematoxylin. By either of these
methods the network is stained black, while the spaces between
the meshes are colourless and appear empty.

When stained by either of these methods, the fibres, as seen
in cross section, are of a somewhat different appearance from that
already described, for, instead of the lines running through the
myelin, black bands are seen with white spaces between them.

Osmic acid stains the network (of the formalin hardened
substance) a faint brown.

The appearance of nerve fibres hardened in formalin is the
same whether teased, stained, or mounted in glycerin, without the
use of alcohol, or soaked in alcohol and ether, as for celloidin
embedding.

When nerve fibres (also tissues from the central nervous system)
are stained by Weigert's method after formalin fixation, the reduc-
ing fluid should be diluted from five to ten times with water,
otherwise the decoloration will be too rapid and uneven.

From the results above described it would appear that formalin
is a valuable addition to the list of reagents for the fixation of
nerve fibres.

The Cebus and the Matches. — Prof. E. D. Cope, writing
to the American Naturalist, says : — " A Cebus apella in the Phila-
delphia Zoological Garden has become an expert in striking
matches. He distinguishes the end with the fulminate, and I
have not seen him make an error in this point. He seizes the
match at the proper distance from the fulminate and so avoids
breakage. He uses for friction the rough side of a kettle which is
used for water, and spends no time on the glazed surface. As
soon as the match is lit he throws it away, and I have not seen
him burn himself. No man could handle the match more appro-
priately. He does not, however, always select a proper surface,
as he tried on one occasion to strike a match on my finger
without success."

[ 17 ]

Xouie pastcun

Bv H. W. Conn. From Science (U.S.A.).

NEVER has the world been called upon to lament the death
of one whose life was so full of gifts to humanity as that
of Louis Pasteur. Others have lived with equal genius,
others there have been whose influence upon thought has been
equal or greater. Others have attained an equal reputation from
achievements of various kinds ; but no other man in the history
of the world has given to mankind so many valuable gifts as those
which have come from the labours of Pasteur. That Pasteur
possessed great genius is manifest, but yet it was not wholly genius
that explains his marked preeminence, for a certain modicum must
be attributed to the timeliness of his work. His greatness was
due in a measure to the fact, that early in life he had the fortune
to have presented to his attention, and the wisdom to seize upon
great problems for solution. He early seized for his own an
almost new field of research, and brought to this new field an
equipment entirely different from that which any other scientist
had possessed. Pasteur is regarded as the father of modern bac-
teriology, but we must remember that he was not a pioneer in
these lines of work. There was hardly a problem that he studied
which had not been already recognised, and even studied to a
greater or less extent by his predecessors ; but at the same time
there was not a single problem which Pasteur undertook to solve
which was not when he undertook it in a most crude, unsatisfac-
tory condition, and when he left it, in its almost perfect form. It
was in reaping fruits where others failed, and in perfecting the
work which had been begun by less competent scientists, that
Pasteur's merit lies. Others discovered facts, Pasteur determined
laws.

In looking over the life of Pasteur as a whole, we are struck
forcibly with two characteristics. The first was its almost uniform
success. Doubtless Pasteur occasionally failed in his experi-
mental work. But of this the world has known nothing, for his
conclusions seem to have been always correct. So far as Pasteur
has appeared before the public from the beginning to the end of

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. c

18 LOUIS PASTEUR.

his career he has enjoyed an uninterrupted success. The French
people have slowly learned to recognise this, and finally acquired
such a confidence in him that it has been a popular saying which
has met all criticisms that " Pasteur never makes mistakes^ This
unique testimony of public confidence is unexampled, but it
seems to have been well deserved, for certainly no scientist has
ever held such a position before the public and made so few mis-
takes. This is the more remarkable when we remember that he
was working in an almost unexplored field. The reason for this
uniform success lies primarily doubtless in the nature of the man ;
but not a little of it we may attribute to the fact that in his early
training Pasteur was a chemist rather than a biologist. While
Pasteur's reputation will rest upon his work in biology he was edu-
cated as a chemist, and to this education we may attribute no
little of the uniformity of the success of experiments. The
science of biology is extremely inexact. Owing to the complicated
conditions of life one is ever expecting to find exceptions to the
general rules, and our scientists have found it utterly impossible to
lay down absolute definitions or any absolute lines of distinction
between groups in biological phenomena. The very essence of
biological science is the fact that the phenomena grade into each
other. Influenced by this fundamental principle, biologists have
commonly fallen into a habit of slackness in dealing with pheno-
mena. Knowing that whatsoever law they may discover will be
sure to have its modifications, its variations, and its exceptions,
they inevitably get into the habit of feeling that an approximation
toward accuracy is almost sufficient. Now, the peculiar nature of
the field of experimentation in bacteriology demands above all
things most rigid accuracy. His training as an analytical chemist
gave to Pasteur a recognition of the importance of exactness.
One who has carried on experiments in molecular physics recog-
nises that failure is sure to result from inaccuracy ; and it was the
fact that until he was 30 years of age Pasteur was trained in this
kind of accurate experimental manipulation that, when he turned
his attention finally to biology and problems connected with the
microscopical world, his methods of experimentation and the
results of the experiment showed at once a vast advance over
those of all of the biologists which had preceded him. For the
first time accuracy began to be seen in this field.

LOUIS PASTEUR, 19

A second striking feature in Pasteur's life was its dramatic
character. One hardly looks for the dramatic in the achievement
of scientific results. But Pasteur was a Frenchman, and, although
thoroughly modest, he was, like other Frenchmen, alive to the
advantage of public demonstrations. As we look through his life
we can see him taking many and many an opportunity of present-
ing his scientific results in as dramatic a style as possible. Meet-
ing with opposition almost constantly during the years of his
active investigations, time and time again he planned public tests
in which his results should be brought before the public eye for
demonstration in such a fashion as to appeal in a striking manner
to the world. No other scientist has ever achieved so many
brilliant public successes.

We must above all things learn from Pasteur's life that, after
all, the chief reason that his reputation advanced so rapidly in the
comparatively few years of his active work, was in no small
measure the fact, that he had the wisdom to see that it is to the
application of science to practical life, that the world in general
gives the greatest admiration. There is ever a tendency among
scientists to belittle one of their number who attempts to apply to
practical life the results of research. In spite of every plea that
may be made for pure science, it is the application of science to
the life of man that has the greatest interest to mankind. As we
look through Pasteur's life and study the growth of his wide repu-
tation, we shall find that his reputation was largely founded upon
the brilliant epochs in his history, where he applied to practical
subjects the results of the scientific investigation. The advance
in his reputation came at those occasions, when the public learned
of his work, because it had been applied to something that
interested the world. The homage that the world has given to
Pasteur testifies to the value of practical science, testifies to the
truth of the position that pure science is of value to man
chiefly as it can be applied to facts which influence practical life.
While, then, applied science is frequently mentioned with a slight
disdain by the modern advanced scientist, it is well to remember
that Pasteur, whose reputation as a scientist has perhaps outranked
that of any man of the last fifty years, made his reputation and
achieved his world-wide fame, because he applied to the practical

20 LOUIS PASTEUR.

things of life the discoveries revealed to him by his microscope.

The active part of Pasteur's life was so full of investigations in
many lines that it is impossible that they should, in a brief review,
receive the weight which they deserve. Only the most important
of them can be here mentioned, a selection being made of those
upon which his reputation has been chiefly built. Pasteur
received an early training as a chemist, and the first work of his
life was chemical. Until he had reached about the age of 32 the
work he had been doing had been mostly in the line of molecular
physics, and certain papers upon the structure of crystals appeared
from his pen, which even in those early years showed signs of
genius. He would probably have made his mark as a chemist
had not his attention been turned to a more fruitful field. In 1854
he was appointed Dean of the University of Lille, and it was at
this place that his attention was first turned in the direction which
subsequently made him famous.

A simple incident led him to the study of fermentations in the
manufacture of certain chemicals. The crystallisation of tartrates
had earlier interested him, but now he noticed that tartrate of
lime had a tendency to ferment. This fact attracted his attention,
and led him into observations and experiments upon the nature of
the fermentation of tartrates. These experiments demonstrated
to his microscope the universal presence of living organisms in the
fermenting material. Finding these fermentations universally
accompanied by living organisms, it appeared to him as probable
that the fact must be part of some general law. It was not a pure
accident that living organisms were present, but in some way he
beUeved there was a connection between the fermentations and the
presence of the organisms. A general law he formulated, and
reached the inference that fermentations in general are produced
by living organisms, microscopical in size, but of very great
potency. This conclusion was, of course, a simple inference as
yet undemonstrated, but it was the inference which started Pasteur
along the line of his experiments in fermentation. It was the
guiding star of Pasteur's life. From the moment the inference
was drawn until his death, this law — that fermentations, putrefac-
tions, and all similar chemical changes were produced by the
growth of micro-organisms — was the basis of every Une of investi-

LOUIS PASTEUR. 21

gation which was undertaken by him. Every new problem in his
life was attacked by him from this standpoint. The great success
of Pasteur's work lay in the fact that his guiding principle was a
correct one, his great merit in his wisdom in early adopting it as a
law, and his genius in demonstrating it. If he had drawn an
inaccurate conclusion from these early experiments, he might in
time have corrected the error, but we must look upon the fact that
he had the wisdom to draw a correct inference from this first work
as the foundation of Pasteur's success in life.

Pasteur now became interested in the subject of fermentation.
His home was in one of the important seats of fermentative
industries, and study of fermentation as a general phenomenon at
once received his attention, not only from its general interest, but
as especially appropriate to his life at Lille. He was thus led
away from the line of pure chemistry into biological work, but the
change was almost imperceptible. Up to the time when Pasteur
began his studies, fermentation had been regarded as a chemical
phenomenon, and it was natural that a chemist should study it.
In the few decades that preceded the work of Pasteur, fermenta-
tion had been carefully studied by a number of our chemists and
microscopists. While different theories had been advanced, the
theory of fermentation, which was almost universally held at the
time when Pasteur began his experiments, was that of the chemist
Liebig, and was a purely chemical theory. In accordance with
this theory of Liebig, fermentation is simply the chemical decom-
position of bodies produced by the unstable equilibrium of their
molecules. This theory held that the molecules of fermentable
materials were very unstable, and were easily broken to pieces into
simpler compounds. The ferment was held to be simply an
exciting cause which started this chemical decomposition. Fer-
mentation was thus a purely chemical subject at the time when
Pasteur began his studies, and the first work which he attempted
was to show that the chemical theory of the scientists of his day
should be replaced by the physiological or biological theory,
which he was convinced from his experiments was the correct one.
Upon this task he set himself at once, and by the study of the
lactic fermentation of milk, the butyric fermentation of milk, the
acetic acid fermentation in the manufacture of vinegar, and by the

22 LOUIS PASTEUR.

numerous careful experiments along these various lines which he
devised in his laboratory, it required only four or five years for
him to undermine completely the chemical theory of Liebig, and
to put in its place (on a somewhat unstable basis at first, perhaps)
the theory that all types of fermentation are organic in their nature
and produced by the life of microscopic organisms. Even at this
early day we can see his recognition of the value of the practical
application of science, for among the very early pieces of work
which he performed was the study of the acetic acid fermentation
in the making of vinegar, and by a practical application of his
results to this industry he developed a vast improvement in the
manufacture of vinegar and a great cheapening of the process.

Pasteur had thus made something his oimi, and at this date, in
the vicinity of i860, he became recognised as the exponent of the
biological theory of fermentation. From this time he progressed
rapidly. The fermentation of wine next claimed his attention.
Here was a second fermentative industry, in which unexplained
difficulties were constantly occurring. He soon found the cause
of the various failures of the vintner, by which were produced
many of the so-called "diseases of wine." These diseases, he
found, were all due to the presence of improper micro-organisms
during the fermentation instead of the pure fermenting yeasts, and
he quickly devised a remedy for them in a process that has subse-
quently been known by his name as the process of pasteurisation.
This method of preventing the evils, involving the heating of wine,
was received with great opposition, on the ground that the heating
injured the flavour. After a great deal of more or less violent
disputing on the matter, Pasteur arranged for a public test of the
question by getting together a large number of experts and con-
vincing them against their will, by ingeniously devised deceits,
that they were unable to distinguish between wines that had been
pasteurised by his process and wines that had not been subject to
heat. Having previously shown that the method of pasteurisation
was almost a sure remedy against the various diseases, this first
public demonstration was thus a brilliant success, and at once
obtained for his method the acceptance of the vintner.

Meantime, he had been giving his attention to the vexed
problem of the last two or three centuries — namely, the ques-

LOUIS PASTEUR. 23

tion of spontaneous generation. Believing, as he did, that
all fermentation was caused by micro-organisms, it was a fore-
gone conclusion that he would be an opponent to the view of
spontaneous generation. The studies upon fermentation which
he had been carrying on, and his accurate methods, trained
him especially well for this subject of spontaneous generation, and
the experiments which he instituted brought this question into the
condition of demonstration. The experiments of early scientists
were repeated by him with greater care ; many new experiments of
his own were devised ; the microscope was brought into requisi-
tion in new ways. A brilliant conclusion was reached, that by the
exercise of sufficient care all traces of life could be avoided, and
no spontaneous generation ever occurred. It is true that the con-
clusions of Pasteur were not at once everywhere accepted. In
England, particularly, objectors arose who advocated a belief in
spontaneous generation, and these objections were not silenced
until the EngHsh physicist, Tyndall, took up the experiments that
Pasteur had been making, and even more satisfactorily reached
the same conclusion. But Tyndall's results were only those that
Pasteur had reached before, and we recognise to-day that the only
basis of the objections that were made to Pasteur's conclusions
was the inaccuracy and lack of care with which his opponents
performed their experiments. With brilliant rhetoric and loose
experimenting, spontaneous generation was still advocated, but the
disproof was given by Pasteur in spite of the fact that opposition
still arose after the disproof had been reached.

But now Pasteur's attention was to be turned again, and in a
direction that again changed his whole life and has revolutionised
modern medicine. One of the great industries of France is that
of the silkworm raising. About 1850 there appeared upon the
silkworm farms a disease of the silkworm known as pebrine. This
disease spread rapidly from farm to farm, greatly reduced the
productions of the silkworm farms, and actually threatened the
entire destruction of the silkworm industry. From 57,000,000
pounds per year, in thirteen years this industry had fallen to
8,000,000 pounds, all because of the great devastation produced
by this disease. Many had been the attempts made to cure it
and many the attempts made to discover its cause. Men with a

24 LOUIS PASTEUR.

reputation greater than that possessed by Pasteur, at the time, had
attacked the problem and failed. In the year 1865 no remedy
had been discovered, no cause was known, and the silkworm
industry was threatened with immediate destruction. Pasteur was
asked to investigate the question, and at first refused to do so.
His success in the study of fermentation had opened to him a
prosperous career ; he knew nothing whatsoever of silkworm rais-
ing, and he was afraid that the investigation, even if successful,
would lead him too far from his own chosen line of work. He
was, however, over-persuaded, and finally accepted the task of
investigating pebrine, little thinking that it was only the continua-
tion of his studies on fermentation, and that along the line opened
to him by this investigation he was to find his life-work and
world-wide reputation. Pasteur undertook the investigation of
pebrine already prepared for his discoveries, for living micro-
organisms were for him potent agents in nature. He very soon
discovered that the cause of the disease was a microscopic organ-
ism living in the moth. He was not the first to discover this
organism, for others had seen it and described it.

That Pasteur succeeded where others failed was due to the fact
of his belief in the powers of the microscopic world. Others
regarded these organisms of no importance, but Pasteur had
become so imbued by his study of fermentation with the import-
ant agency of microscopic organisms, that the very first question
that he asked was whether living bodies were not the cause of the
disease that he had been set to investigate. If organisms could
produce fermentations in dead material, why might they not
produce disease in living creatures ? The result of his work here
we need not dwell upon. It was a brilliant success. It demon-
strated that the disease was caused by the organisms, and it
devised a remedy against the trouble by simply breeding from
healthy moths. The world laughed at him ; those interested in
the silkworm industry refused to adopt his methods, as those of a
fanatical microscopist, and too simple. He met at first with
nothing but opposition, but the man arose to the occasion, and so
sure was he that he was right that he again arranged for a public
demonstration. An abandoned silkworm farm was put into his
hands, and, although at the time an invahd and unable to travel

LOUIS PASTEUR. 25

by ordinary means, he had himself transported across France and
personally directed the work on this silkworm farm, although he
was unable to do anything himself.

It is not, perhaps, generally known that from this time to his
death Pasteur was partially paralysed and unable to perform the
work of his own experiments. There is something truly pathetic
and dramatic as we think of him, an invalid, simply capable of
directing others in their work, and yet fired with the belief that he
was right, and with the determination to convince the world that
he was right. Again Pasteur's genius demonstrated itself, and, by
using his simple remedy, in a short time this silkworm farm,
abandoned because of the presence of the disease, was restored to
a condition in which it was one of the best-paying silkworm farms
in France. The disease was practically eradicated from it. With
a bound Pasteur's reputation spread throughout France and the
world. The silkworm industry in France began to adopt his
methods at once and rapidly assumed its old condition of prosper-
ity. From now on the Frenchmen were ready to accept almost
anything that Pasteur would say. He had saved them their
beloved silkworm industry, and had been the means of saving to
the peasants of France a sum of money almost beyond belief.

The next important work in Pasteur's life was his investigations
upon the subject of the fermentations of beer. The Franco-
Prussian war and its results had deprived the French people of
their beer-makers, who had been largely German, and when the
French people began to make their own beer they found them-
selves for awhile in difficulties. In spite of careful methods,
various imperfections in fermentations were of frequent occur-
rence. By this time the French public had become confident in
Pasteur's abilities, and it was only natural that he should be
requested to find the solution for this puzzle. As usual, success
attended his efforts. His microscope soon showed him that the
trouble was due to the use of impure yeasts. The brewer's yeast
was liable to be mixed with various species of bacteria as well as
improper species of yeasts, and his genius soon showed methods
of removing the difficulties and bringing the fermentative industry
into a condition of uniformity. Upon the basis of these experi-
ments has been founded the whole of our modern brewing

26 LOUIS PASTEUR.

industries. The large brewery of to-day is impossible without the
microscope, and to the stimulus given by these discoveries of
Pasteur has been due the great centralisation of brewing.

The next problem that attracted the attention of Pasteur was
the dreaded anthrax. For several years this devastating disease
had been the subject of scientific investigation. Already its con-
nection with micro-organisms had been made probable, and indeed
had been demonstrated. Many problems had been solved, but
many still remain to be solved in connection with this pestilence
of the agriculturist. As usual, Pasteur began at the beginning,
taking nothing for granted, even of the facts that had been essen-
tially demonstrated. His experiments resulted in a more complete
demonstration of the relation between the anthrax bacillus and the
disease, showed the method of action of the germ, demonstrated
the source from which it was frequently derived by cattle, differ-
entiated between this disease and one or two others closely
resembling it among animals, disproved all of the objections that
had been raised by those who disbelieved in the casual nature
of the bacilli, and, in short, brought this subject upon the same
sure foundation as that of pebrine which he had so triumphantly
solved ten years before. Nor was this all. The greatest dis-
covery of his life was to follow. To Pasteur's pecuhar trait of
mind it was not enough to discover the cause without searching
for the remedy. It was the practical question which appealed to
him. Pasteur recognised the fact that in the human race one
attack of an infectious disease frequently renders an individual
immune against a second attack. He also remembered that pro-
tection against small pox had been known to be produced by
vaccination.

Acting upon these suggestions the questions arose in his mind
whether it was not possible to give to domestic animals, subject to
this devastating disease, a milder type of the disease in question,
from which they should readily recover, but which would give
them immunity against a second attack. The principle was a new
one, and outlined a new, bold plunge into the mysteries of nature.
It was not, however, in the investigations of anthrax that the
remedy first suggested itself, but rather in a side investigation upon
the subject of another germ disease known as fowl cholera. Every

LOUIS PASTEUR. 27

one is familiar with the results. He discovered a method of ren-
dering the invading organisms of fowl cholera so impaired in their
action as to be unable to produce death, giving rise, on the con-
trary, simply to a slight indisposition ; but demonstration soon
showed him that this slight indisposition was followed by immunity
against the more severe disease. To anthrax he turned the same
line of investigation, and after patient, laborious search discovered
a means of rendering the anthrax germ impaired in its vigour.
His preliminary experiments convinced him that he had achieved
success, and then came one of those dramatic public exhibitions
in which Pasteur so delighted, and which have so impressed the
world. Almost before the public had learned that he had obtained
a possible method of preventing this dread disease among agricul-
turists, Pasteur made arrangements for a public test of his method,
and in the presence of an audience of some two hundred experts,
made up of physicians, veterinarians. Senators, prefects, farmers,
members of the French Academy, and others of high standing, he
demonstrated by a simple experiment, lasting about a week, that
he could, with unerring certainty, prevent cattle from acquiring
anthrax; that he could give to them a practically absolute immu-
nity against this almost surely fatal disease, by infecting them with
a very mild indisposition a few days before. The effect upon the
audience was electrical, and their enthusiasm knew no bounds.

Pasteur's experiments spread at once over the world, and from
this further practical application of his scientific research his reputa-
tion made another advance. His anthrax vaccine was distributed
through the civilised world, was used by grazing communities
everywhere, and it has been thought to have saved the lives of
hundreds of thousands of cattle. The greatness of this discovery
can hardly be appreciated to-day. It was a logical discovery of a
new method of meeting disease. While other even more valuable
discoveries in the same line have followed and are still to follow,
none can equal in significance this first application of the studies
of the microscope to the treatment of disease.

Following the work upon anthrax, various other lines of bacteri-
ological research connected with diseases of animals attracted his
attention and demanded his time. It was not, however, until he
had attacked the problem of the most dreaded of all human dis-

28 LOUIS PASTEUR.

eases, hydrophobia, that he again attracted the public eye. His
experiments upon hydrophobia were, perhaps, the boldest in the
line of experimentation that had ever occurred, for here for the
first time in history laboratory experiments were transferred to the
human being. Hydrophobia had fascinated Pasteur for a long
time. Experimental work had shown him that the disease was
not a purely nervous excitation, as had been claimed, but that
there was an actual disease under this name. Experiments showed
him further that the disease bears every similarity to infectious
germ diseases, although neither he nor anyone else, even to the
present day, have succeeded in demonstrating the organism which
produces the diseases. Experiments upon dogs and rabbits in his
laboratory followed each other rapidly, and, with his usual genius,
he devised many a method of hastening the experiments, and of
rapidly teaching results which would normally take months.

His success with other diseases made him ambitious also to
find a method of preventing this disease, and, while the methods
which he had used in fowl cholera and anthrax proved useless in
the case of hydrophobia, the same general line of work led him
finally to a method of inoculating animals which rendered them
immune against this disease. Not only so, but the same method,
when applied in a slightly different way, was found to be effica-
cious in warding off the disease in an animal which had been
previously inoculated therewith. He found himself able, with
certainty, to inoculate an animal with hydrophobia, and then, by
treating him with the various subdermic injections which he had
devised, prevent the appearance of the disease which would have
otherwise inevitably occurred. Laboratory experiments were a
success, and next, the bold step was taken of applying to mankind
laboratory methods, which had been hitherto tried upon animals
alone. A youth who had been severely bitten by an unquestion-
ably rabid dog was brought to him at his laboratory. The youth's
life was despaired of by the physicians, inasmuch as with certainty
he would develop hydrophobia. Under the circumstances Pasteur
felt justified in trying upon this youth the experiments that had
succeeded with dogs and rabbits. The experiment so far as could
be demonstrated was a success. The youth failed to develop this
disease.

LOUIS PASTEUR. 29

But for a final demonstration that his methods were suc-
cessful, was required a long series of public experiments which
were not to be obtained by any one dramatic incident. To obtain
such testimony no means appeared to be possible except to
announce to the public the discovery of a method of preventing
hydrophobia. Such an announcement was made by Pasteur.
The public had such unlimited confidence in the man that they
at once accepted the conclusion as correct. Certain it is that no
one else could have taken the public into his experiments, but his
uninterrupted success in previous years gave all a belief that he
had made no mistake here. Opportunities for experiment began
to multiply, and scores and then hundreds of individuals who had
been bitten by animals, either rabid or supposed to be rabid,
flocked to the laboratory of Pasteur to be treated by his method.

The experiments thus begun have continued for eight years,
and even yet can hardly be considered as concluded. The
opinion of the public, and especially of the medical world, has
vibrated from one side to the other. At first, Pasteur's conclu-
sions were accepted as probable, simply on the basis of the great
reputation of the man, and the fact that Pasteur made so few
mistakes. Later, flying to the other extreme, the whole efficacy of
the method as practised by Pasteur was doubted. Most violent
opposition arose, and it is thought that this opposition contributed
to undermine Pasteur's health and check his active life. Later
again the world became slowly convinced, by the accumulating
testimony in his Institute, that here too no mistake had been made.

At the present time there is hardly a question that Pasteur's
methods, even in the case of hydrophobia, have demonstrated
themselves as successful. While statistics are a very uncertain
kind of evidence, one cannot read of the success which has
attended the inoculation in Pasteur's Institute for eight years
without being convinced that Pasteur's methods are correct. In
his Institute have been treated several thousands of cases of per-
sons bitten by animals supposed to have been rabid, and among
those that have been treated the number of deaths has only been
a trifle over one per cent. With this exceptionally small per
centage, even after we say everything possible as to the uncertainty
of statistics, we can hardly question that truth underlies these

30 LOUIS PASTEUR.

methods, and that Pasteur's last great work was as successful as
those of his earlier years.

This work upon hydrophobia was the last piece of work which
we have directly from Pasteur's own personality. A Pasteur Insti-
tute was established, and from that Institute has couie, and is still
coming, a series of investigations along the lines that Pasteur
began, which are yearly adding, not only to our scientific know-
ledge, but to our practical method of dealing with disease. While
Pasteur's name is no longer attached to these individual researches,
the master's hand gave the inspiration for them all. For several
years the experiments have all been in the hands of his assistants.
While we have looked upon them as his assistants, we must recog-
nise them as independent and as having achieved their own
reputation ; but, nevertheless, we must feel that the work that has
come from Pasteur's Institute, and that will for a number of years
be given to the world from that source, must be directly or indi-
rectly attributed to the inspiration of the master for whom the
Institute was founded.

The world's debt to Pasteur we never can estimate. His
financial gifts we can realise when we remember that he saved the
silkworm industry, that he taught the vintners how to make wine,
that he established the fermentative industry the world over, and
that he gave to the agriculturists a method of preventing anthrax ;
we can see that the financial value of his life to the world was far
beyond that of any other person that ever lived. The debt of
theoretical science to him is equally great, though not measurable
in any terms. He disclosed a new world ; he discovered a new
series of phenomena taking place below the realm of human vision,
and he opened to the world a new field of science. To medicine
again his gifts were beyond measure. To him more than to any other
is due the demonstration of the germ nature of disease, and to his
work we owe our hopes for medical science in the future. The
practice of medicine has been almost purely empirical. To-day
we are hoping that it is gradually becoming a matter of science.
As we know the causes so we can search for the remedies against
disease, and to Pasteur is due the first attempt to place medicine
upon a scientific basis. Surgery has already become a science,
and this too is indirectly attributable to him. While modern sur-

LOUIS PASTEUR. 31

gical methods were developed by Lister, the methods of Lister
were devised as the result of the study of Pasteur's work in fermen-
tation. Pasteur has opened to us a new world and given to us a new
science, has established upon a firm basis a science of medicine
and a science of surgery, and has added to the financial stores of
the world accumulations of great magnitude. It was all done by
slow work. The field was not a new one, for already investigators
had made inroads therein, but no one with anything like certainty
and accuracy.

For years it was Pasteur alone who was capable of investigat-
ing bacteriologically with anything like a certainty of successful
issues. Bacteriological methods were too difficult to be handled
by anyone but a master. To-day it is true the methods have
been so simplified that far less genius has been required to handle
them, and to-day the bacteriologist has multiplied in every direc-
tion. But at the time when Pasteur was the pioneer, the methods
were so difficult as to be beyond the reach of any except those of
the greatest genius. Nor can we measure our debt to Pasteur by
his own work. This, indeed, was great, but our debt to him must
be also measured by the work of followers who were inspired by
him. In France, in England, in Germany, in America, we find
the study into this realm of the microscope inspired by the long,
laborious, and successful work of the French master. Even in
the latest achievement, the use of antitoxine, we have the direct
result of Pasteur's life. Where one leads others may follow.

For a long time Pasteur stood alone, and it was only work
that he had done that could be looked upon as demonstrated.
Little by little, however, others came into the line of research, and
when to-day Pasteur is taken from the field of activity there are
many capable of carrying on his work. No man that France has
created is so worthy of her pride. No man who has lived in
history has done so much for humanity. No one who has lived
will be remembered by posterity as having had such an influence
upon the world in the way of discovering facts which advance the
health and prosperity of mankind. But, perhaps, the proudest
achievement he attained, viewed from the standpoint of a scientist,
was earning the right to the claim that ^^ Pasteur never makes
mistakes^

[ 32 ]

Diatomoloo^ as an Bib to (Bcoloo^-

By M. J. Tempere.*

WHO would maintain at the present time that the study of
Diatoms is of small importance, and not recognise that
as much and even more than any branch of Cryptogamia
it has a right to be classed among those which can powerfully aid
the researches into the secrets of Nature that are the most difficult
of solution ?

Diatomology exists. It is a science which nevertheless has
not received the unanimous sanction of learned men, for in the
best treatises on Botany there is scarcely any mention of Diatoms
and of their importance in Nature.

The study of Algae in general, of Mosses, Fungi, and of
Lichens, is honoured everywhere. There is not a university, a
faculty, or a large school, that does not reckon among its savants
those who occupy themselves with the different branches of cryp-
togamic botany ; but of Diatoms, none ! — at least in France, for
among foreigners I could mention many, among whom are two of
our collaborators.

The reasons that I have heard given as an excuse for this
neglect appears to me so ill-founded that they are hardly worth
noticing ; some of them even appear to me to be only the expres-
sion of one who will not discuss the question.

In our last number I mentioned the observation made by
Prof P. T. Cleve, of Upsala, on the identity of the species found
on the coast of Greenland and on the north of Asia, giving rise
to the idea of a current between the two opposite points, and thus
aiding the solution of a hydrographical problem

To-day, by the reading of a brochure having the title, Prelimi-
nary Report on the Physical Geography of the Littorina Sea, by
Henry Munthe (a work published in the Bulletin of the Geological
Society of Upsala, No. 3, Vol. 11., 1894), I have seen with pleasure
that at length a geological savant, not content to borrow from
Paleontology for proofs in aid of his deductions, relating to the
successive changes to which the Baltic Sea has been subjected,

* Le Diatoiniste, li., 1894, pp. 129 — 130.

PREPARING ORTHOPTERA. 33

has appealed to Diatomology by requesting our colleague, Prof.
P. T. Cleve, to study the species contained in those beds which
present distinct characters of these transformations, so that he
may be able to add another proof to those which he has already
obtained.

Already for some time researches and comparative studies have
been undertaken by a certain number of diatomists with this
object in view, and I am certain that from these studies the
importance of Diatomology will result, and that one day they will
place it in the first rank.

The recent labours of Dr. P. Miguel have evidently contri-
buted much to this, end, in offering to diatomists new methods of
study, which enable them to follow the different phases of the life
of these organisms, their transformations, and to compare that
which they can obtain in their laboratories with that which Nature
presents.

IPreparlno ©rthoptera.

IN Special Bulletin No. 2 from the Department of Entomology
of the University of Nebraska, Prof Lawrence Bruner gives
excellent directions for collecting and preserving Orthoptera.
Regarding the process of stuffing he says : Within the past few
years most of the objections that had so frequently been made to
the gathering and preservation of orthopterous insects, have prac-
tically been removed by the adoption of different and better
methods of preparing and preserving these creatures. A few of
our specialists only seem to have profited from the discovery that
these insects can be handled ' taxidermically,' i.e., be stuffed in a
similar manner as we would adopt for birds, reptiles, and mammals,
and thereby preserved, in collections equally well with other forms.
The following directions for collecting, cleaning, and ' stuffing '
orthopterous insects may, therefore, be of much value to those who
contemplate making collections of, and studying these insects : —
Instead of throwing the specimens in spirits (alcohol, brandy,
whisky, etc.), when captured they should be killed in the 'cyanide'

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. d

34 PREPARING ORTHOPTERA.

bottle, from which they should be removed soon after death, and
at once opened, cleaned, and stuffed ; or they can be transferred
to a small tin or other box, where they may be kept moist and
flexible till arrived at home or in camp. Now take the specimens
one at a time in the left hand, and with a fine, sharp-pointed scis-
sors open the abdomen by cutting across the middle of the two
basal segments on the lower side, then reverse and cut the opening
a trifle larger by nearly severing the third segment. After this has
been done extract all the insides (intestines, crop, ovaries, etc.)
along with the juices, using a fine pointed forceps for the purpose ;
wipe out the inside of the insect with a small wad of cotton, and
it is ready to be ' stuffed ' or filled up. When this latter is done
the insect may be either pinned into a box prepared for the pur-
pose at once, or it can be wrapped in paper and packed away for
future use.

To " stuff"," cut some cotton bat (raw cotton) in short pieces,
and fill up the insect through the opening previously made for
cleaning it, using the same or a similar pair of forceps for the
purpose, taking care not to fill too full nor to stretch the abdomen
beyond its original dimensions. When the filling is completed
carefully draw the edges of the several segments together, and
gently press the sides of the abdomen into shape with the fingers.
This can all be done after a little practice in about four or five
minutes' time. The advantages in favour of a specimen thus
handled are several. It will not decay nor turn dark. The origi-
nal colours will be retained more nearly perfect, and there is but
little danger, under ordinarily careful treatment, of its being
attacked in future by the museum parts mentioned. Specimens,
when thus prepared by an expert and properly labelled, are worth
three or four times as much for cabinet specimens as those not so
cared for. Especially is this true with reference to specimens col-
lected in warm, moist climates where decay is rapid, and where
mould is sure to attack specimens that are long in drying. — -
American Naturalist.

[ 35 ]

pre^^ciou6 c^ iparaeitic lEnemtce of Bphtbce

(^ncluDino a Stu&» of 1F5>?per*para6ites).

Bv H. C. A. Vine.
Part III. — (concluded). Plates I. and II.

IN the foregoing studies of Aphis-eating insects which have
appeared in these pages, I have endeavoured to show the
connection of each of the species under immediate observa-
tion with those nearly allied to it, and at the same time to indicate
the position held by the particular group in the systems of classifi-
cation which have been established by leading naturalists.

In order to follow this course with the Neuropterous Aphis-
eaters, it is necessary to go somewhat further. The position of
the typical forms of the order has long been the subject of dispute,
and as it involves the question whether or not the Aphis-eating
families are to become the types of the order, it perhaps will not
weary the reader too much to examine in the present section some
of the evidence bearing upon this important point

I have already alluded to the very remarkable and wide differ-
ences of structural detail in the species of the Neuroptera, and
these, combined with the fact that a number of families undergo
what has been called an ' incomplete ' metamorphosis, have led
many naturalists to pass by the strongly marked features connect-
ing the dragon-flies and allied sections with the lace-wings and
caddis-flies, and to transfer all those species which are active, and
continue to feed, during their pupal existence, to the Orthoptera,
the ' incomplete ' metamorphoses of which are, however, of a very
different type to those of the species which it is thus proposed to
associate with them.

To discuss at length the whole question of the value of the
form of metamorphosis as an ordinal character would be beyond
my present scope, and would import into my subject much that
would be wholly unconnected with it ; but before passing on we
may usefully glance at some important points, and note the views
which have been expressed by naturalists who have been favoured
with especial opportunity of forming correct conclusions.

Mr. G. B. Buckton, in his recently published work on one of

36 PRED\CIOUS AND PARASITIC

the Syrphida {Erista/is tenax) says of larval adaptation generally :
"Adverse surroundings may be successfully combated by larvsei
and we may therefore conceive that certain organs may become
profoundly modified so as to meet the requirements necessary for
the struggle in life. The study of larval history will thus appear
to become more and more important, as these facts are generally
admitted "

Sir John Lubbock, in his excellent treatise on the Origin and
Metafuorphoses of Insects, maintains the proposition " that the form
of the larva depends very much on the conditions of life," and
after an able argument, based on many apt examples, he concludes
" that the form of the larva in insects, whenever it departs from
the hexapod Campodia type, has been modified by the conditions
under which it lives. The external forces acting upon it are dif-
ferent from those which affect the mature form, and thus changes
are produced in the young which have reference to its immediate
wants rather than to its final form."

" And lastly, as a consequence, that metamorphoses may be
divided into two kinds — developmental and adaptional or adap-
tive." In another place the same writer says: — "The metamor-
phoses of insects depend then primarily on the fact that the
young quit the egg at a more or less early stage of development ;
and that consequently the external forces acting upon them in this
state are very different from those by which they are affected
when they arrive at maturity."

For my own part, I find it somewhat difficult to see how,
granting an evolutionary origin of species, a variation in the mode
of development, such as the ' incomplete ' metamorphosis pre-
sents, can be made a ground for separating insects which are so
clearly connected by important points of general structure, by
wing venation, and by resemblance of larval form and food (albeit
one is adapted for aquatic and the other for terrestrial existence),
as Calepteryx and Myrmeleoti, which are shown on Plate I., at
Figs. I and 2.

Moreover, I would emphasise most strongly the point that the
metamorphoses of insects, although they have been divided into
four distinct stages by so many generations of naturalists that their
definite existence has become almost an article of faith, are in

ENEMIES OF APHIDES. 37

reality by no means so sudden as is generally thought. The
observant student will recognise that they are merely stages in a
series of developments, often aberrant in a most remarkable
degree (as, for instance, in the case of Sitaris), but always pro-
gressive, and that the apparent arrest of the pupal stage is due to
the changes attending the development of the perfect insect within
the larva having become so extensive and so rapid that it would
be impossible for the functions of the latter to be continued fur-
ther. The conversion of the grub into the fly has commenced
long before the pupal stage is entered upon, and in many of the
orders the casting of the larval skin marks successive advances in
the development of structure which ultimately go to form the
perfect imago. A marked instance of this has already been given
in these pages in reference to the larva of Coccinella bipmictata,
Vol. IV., p. 292, and in the plate accompanying I have shown the
tarsus of the imago already perfected within the limb of the larva.
Indeed, in very many instances, the careful examination of a larva
when approaching its full growth will reveal much of the structure
of the imago well advanced within it.

The larvae of the Orthoptera, as a whole, closely resemble
their parents in habit and also in anatomical structure, with the
e.\ception of the absence of wings. They frequent the same
surroundings, the organs of the mouth are the same, and their
nutriment is of a similar character throughout their existence.
To quote once again from Sir John Lubbock : — •" In the wingless
species of the Orthoptera there is little external difference, except-
ing in size, between the young larva and the perfect insect. The
growth is gradual, and there is nothing which would in ordinary
language be called a metamorphosis. In the majority of Orthop-
tera— though the presence of wings produces a marked difference
between the larva and the imago — the habits are nearly the same
throughout life, and consequently the action of external circum-
stances affects the larva in the same manner as it does the perfect
insect."

But among the Dragon flies and their allies the larvae differ in
almost the widest possible sense from the imagines which spring
from them. Specially adapted for aquatic existence, provided
with branchial respiration and with swimming feet, the only

38 PREDACIOUS AND PARASITIC

character which they possess in common with the perfect insect is
the rapacious appetite which impels them to attack the other
inhabitants of their haunts. The imago, on the other hand, is
one of the most beautiful of insects, fulfilling an aerial existence
and provided in the most perfect manner with tracheal respiration
and ample wings. " The larvae do not live under the same condi-
tions as the perfect insects. External forces accordingly affect
them in a different manner, and we have seen that they pass
through some changes which bear no reference to the form of the
perfect insect. These changes are, however, for the most part
very gradual."

These broad characters seem to militate strongly against asso-
ciating the Odonata with the Orthopiera ; but when we consider
also that, although differing in environment and in certain charac-
ters of an adaptive nature, incidental to their surroundings, the
larvae of the Odonata strongly resemble those of the Planipennia
in general form, in the provision of special mouth structure for an
actively carnivorous existence, and in the unwearied hunt after
prey, it is hardly possible to escape the conclusion that a near
relationship exists between these two groups, and that on these
grounds the Linnean arrangement of the Neuroptera should hold
good.

In the Trichoptera (which is an essentially Neuropterous
group) and in the Raphidiidce we find that the pupae, though in a
great degree quiescent, are, during their later stages, sufficiently
active to walk about, thus presenting an intermediate link between
the silk-wrapped chrysalis of Hemerobiiis and the active ' pupa ' of
Libdhda. The Trichoptera also present, in their habit of catching
their prey, many points of resemblance to the Ant-Lions, which
will not be without interest to an observant student ; and in wing
structure they seem in some respects to favour the venation of
Agrion and in others that of Hemerobius.

To summarise, I am clearly of opinion that, given the principle
of evolution (and we are told by Carl Vogt, " personne, en Europe
au moins, n'ose plus soutenir la Creation independante et de toutes
pieces des especes "), the nature of the metamorphosis in the
Neuroptera is only a question of development, and that any par-
ticular modification may well arise in any group when the condi-

ENEMIES OF APHIDES. 39

tions of life are such as to render the change essential to con-
tinued existence.

Passing from the consideration of the metamorphosis, we will
now examine the second ground on which the removal of the
Dragon-flies from the Neuroptera to the Orthoptera has been
supported.

Mr. W. S. Dallas tells us that " one character almost univer-
sally holds good, and this is derived from the structure of the
ligula. Throughout the more highly organised Orthoptera the
ligula is, almost without exception, divided or cleft in front either
in two or four lobes, and the indications of division may even
continue down into the basal part of the labium, showing very
clearly the original construction of the whole labium from a pair
of organs similar to the maxillae. In the true Neuroptera, although
the ligula is occasionally cleft in front, the general rule is that the
parts of the labium are united in the middle line so closely as to
entirely conceal the original construction of the organ of two
lateral halves, so that the labium really approaches more nearly to
that of the Beetles than to that of the Orthoptera."

This expresses pretty succinctly the views of those naturalists
who propose to break up the Neuroptera as arranged by Linnaeus,
and to place the most important sections with the Orthoptera. As
I have already pointed out, in this event the Aphis-eating Hemero-
biidcB and ChrysopidcB would become the typical genera of the
remaining Neuroptera. To arrive at a correct conclusion as to
the value of the structure of the labium in this group, I have
examined and drawn as many examples of the different species as
possible during the past few months, with the result that I am
disinclined to recognise it as of any weight as an ordinal charac-
ter, although as a generic feature it is a most useful guide.

On Plates I. and II., I have reproduced my drawings with as
much delicacy and exactness as the lithographic process employed
admits, and in addition to the labia of Agrion, Ltbellula, He7nero-
bius, and Sialis among the Neuroptera, the reader will find the
same organ as found in the House Cricket (Gryllus domesticus)
and the Earwig ( Forficularia auricularia), as representatives of
the Orthoptera.

In the labium of Sialis lutaria (PI. II., Fig. 2), which is

40 PREDACIOUS AND PARASITIC

seen from above, the nearest approach to the Coleoptera may be
discerned, the organ consisting apparently of a single lobe of
slight thickness and covered with short hairs. It is without any
external indication of division, and in the drawing is shown partly
hidden beneath an extensive organ, which appears to represent the
true ligula. Possibly, it is this which has led naturalists to recog-
nise a resemblance to the general structure of similar parts in the
Orthoptera.

In the labium of Hemerobius, which is shown at Fig. i on the
same plate, we have a far more normal structure. Here the
central lobe, which appears to be without any trace of division, is
flanked on either side by a smaller lobe, the divisions being very
clearly cut down to nearly the centre of the organ. It is also
pretty evident, on careful examination, that some kind of bi-lateral
structure exists in the central lobe, though, as I have said, there is
no sign of division externally. It resembles the same organ in
Sialis in its short, stout hairs and in the presence of a superior
lobe, which must be assumed to be the homologue of the ligula of
the Diptera. Here, then, in one of the most typical families of
the Plannipentiia, we have a labium, deeply divided, and of a form
widely differing from that of the typical Coleoptera. Indeed, I have
been more than once inclined to suspect the existence of obsolete
or partly atrophied structure resembling the pseudo tracheae of
the Diptera.

In Fig. 3 it will be seen that the labium of Agrion partakes
even less of the structure of the Orthoptera than that of Heviero-
bius does of the Coleopterous formation. In it the middle division
scarcely extends beyond a notch on the frontal edge, and although
the form and arrangement of the hairs suggest the labium of the
former order rather than that of a beetle, yet the general structure
is so utterly at variance with that prevailing among the Orthoptera
that it will scarcely be necessary to pursue the comparison further.

In Libellula (Fig. 4) we find an organ which, under some cir-
cumstances, may be thought to present a definite resemblance to
the Orthoptera in regard to the central division. But a careful
examination of the exterior (ventral) surface, in a natural condition,
reveals no more than an axial depression, which it is difficult to
believe can represent a true division into lobes ; and an examina-

ENEMIES OF APHIDES. 41

tion of the upper, or inner, surface seems to show that the mem-
brane is not divided. But on examination by transmitted light,
and particularly in a transparent medium, such as Canada balsam,
and after treatment by potash, a chitinous division is very appa-
rent, and it becomes clear that we have to do with an organ which,
although perhaps not actually bilobular, approaches so nearly to it
as to have caused observers (viewing it in a transparent condition)
to conclude at once that it presented a definite Orthopterous
character of genuine significance. The chitinous rigidity, how-
ever, is very different to the fleshy organ of the cricket (PI. T.,
Fig. 6) and similar Orthoptera, while the structural arrangement
of the parts presents no analogy, and although an approach to the
orthopterous central division must be admitted, it is by no means
clear that the structure of the labium as a whole is such as to
support any ordinal transference of the genus.

For better comparison of these organs with those of the Orthop-
tera, I have figured upon PI. I., at Fig. 6, the labium of the
House Cricket, which, it will be observed, is a thick fleshy organ,
supported on a muscular and flexible column, and provided with
muscles beneath the frontal lobes, by which they are controlled.
And on PI. II., at Fig. 5, may be seen the drawing of the
labium of the Common Earwig, in which the organ is so com-
pletely divided and altered in character, that it assumes the form
of two thickened single-jointed palpi. The fleshy lobes of the
Cricket present some slight resemblance in shape to the same
organ in certain of the Diptera, although, of course, without the
trachea-like tubes so characteristic of the latter, and neither they
nor the isolated palpus-like labium of the Earwig present any
resemblance to the mouth-organs of either section of the Neu-
roptera.

The characters afforded by the wing venation, which were the
basis of the original Linngean classification, appear to me to indi-
cate very forcibly the unity of the order. On PL I., at Figs.
3 and 4, I have figured the wings of Calepteryx and of Stalls, the
whole of the inner or secondary nervures being omitted, in order
to show the similarity of the principal nervures in these, the most
diverse genera of the two sub-orders. The same main nervures
may be traced without difficulty in Libellula and in Chrysopa, and

42 PREDACIOUS AND PARASITIC

with less certainty in Agrion, Hemerobius, and other genera. In
Fig. 5 of the same plate is shown the wing of Agrion, which, while
remarkable for the rectangular shape of its cellules, presents in
some portions, and particularly in the irregular-shaped cellules
towards the lower margin, a distinct approach to the venation of
Chrysopa, which has been given in previous figures. But a more
curious feature is the manner in which the spaces between the
longitudinal nervures are divided at the extremity of the wing,
showing a relationship with the Trichoptera, in which such an
arrangement is a distinctive feature and of a noticeable character.

The presence of the numerous fine short hairs upon the wing-
veins of Agrioji is also an indication of the affinity between this
genus and the Hemerobiidce. and Trichoptera, in the latter of which
the presence (in greater number) of similar short hairs upon the
wings has given rise to the subordinal designation.

In concluding my remarks upon the wing structure, I would
advise the student to examine for himself the various wings under
a low-power objective, and to note the remarkable visual resem-
blance which is to be seen throughout the whole order — a resem-
blance which can be better realised by sight than by any amount
of description or even of figures.

The last point which I shall consider is one on which much
stress has been laid by some writers, but as to the value of which
I feel considerable doubt in the present state of our knowledge.
No doubt the evidence afforded by embryology has been of great
value to biology and to comparative anatomy ; but the difficulties
which beset its practical application in the study of insects, are a
serious obstacle to forming conclusions of definite value, based on
such research alone. The embryological development of the genus
Calepteryx has been exhaustively studied by Brandt, whose
results are to be found in the Memoirs of the Imperial Academy of
Science at St. Petersburg, and in the German work which he has
published on the subject. With a view to compare the develop-
ment of this genus of the Odonata with the same developments in
one of the Flatinipennia, I have studied the egg-development in
Chrysopa, and have found it in the main to correspond with the
account given by Brandt, though important differences appear as
to the position of the embryo, both in relation to the egg itself
and to the yolk-mass. *

ENEMIES OF APHIDES. 43

It is exceedingly difificult to observe in a satisfactory manner
the earlier changes which take place within the eggs of Chrysopa.
At an early stage, when the egg is broken under the microscope by
pressure, the formation of nucleated cells may be seen to have
commenced, and the first observation I have been able to make is
the initial development of these for the formation of a blastoderm.
Brandt describes the structure at this stage of a blastodermic
envelope with some minuteness, and it appears to be identical
with that of Chrysopa. Prior to this, round or ovoid nucleated
cells are present in abundance, especially towards the lower end
of the egg, and it seems, as might be expected, the formation
proceeds by the subdivision of one or two of these cells, which
are of a different character to the remainder. The primary ger-
minative band floats rather freely on the surface of the yolk-mass.
This is much as Brandt describes in Calepteryx, and to my own
observation the development at this stage appears to be identical,
and to differ considerably from the development in some eggs
which I have examined, in which the band appears to be folded
within the yolk-mass. Later, the band may be observed to turn
inwards, as if about to penetrate the yolk.

After the formation of the blastoderm a change takes place by
the separation of a layer, which seems to be the first indication of
the formation of the viscera, and here the resemblance to Calep-
teryx is again manifest. But in the latter, at an early point, the
germ so changes its position within the egg that the ultimate
position of the head of the larva is remote from that originally
occupied. It is not so in Chrysopa, in which the larval head
remains in proximity to the microphyle throughout the develop-
ment of the embryo. This important difference seems to me to
detract greatly from the value of the otherwise similar embryo-
logical growth.

As the growth of the embryo proceeds, the extremity of the
abdomen becomes recurved so as to enfold the lower end of the
yolk-mass, and the head remains immediately below the micro-
phyle. The first development of limbs and cephalic appendages
is evident at an earlier stage, and during the remainder of the
growth of the embryo it follows precisely the progress of the
embryo of Calepteryx, as detailed and figured by Brandt.

44 PREDACIOUS AND PARASITIC ENEMIES OF APHIDES.

I had hoped, when first examining these delicate changes, to
find evidence of a definite nature as to the coincidence in the
embryological growth of the two genera ; but although the simi-
larities are many and well marked, and are considered by Dr.
Packard to be conclusive, I cannot altogether accept his view, on
account of the change in position of the embryo, and I conclude
that the evidence afforded by embryological examination is too
doubtful to have much weight in the question of the relationship
of the sub-orders of the Neuroptera. But although this pomt is
left in doubt, the general habits and structure of the larvge, the
wing venation of the imagines, and the failure to find any really
weighty indications of a relationship in any genera with either the
Orthoptera on the one hand or the Coleoptera on the other, lead
me to conclude that no sufficient ground has been shown for dis-
turbing the Linnean arrangement of the order.

EXPLANATION OF PLATES I. AND II.

Plate I.

Fig. 1. — Imago of Myrmeleoti, for'micarius.

,, 2. — Imago of Calepteryx virgo.

,, 3. — Principal nervures of wing in Calepteryx.

,, 4. — Same in wing of Sialis lutaria.

In these figures the lettering refers to the similar nervures
in each, a being the cubital point ; hb the anti-cubital trans-
verse nervures ; dd and e the radii ; c is the costal nervure ;
g in Fig. 4 exhibits well the progress of the obliteration of a
nervure, being often scarcely traceable through greater part
of its length.

,, 5. — Wing venation of Agrion puella. This species exhibits an
arrangement of the nervures in the main corresponding with
that of the Odonata generally ; but towards the lower edge
the shape of the cellules and the short, sparse hairs show the
relationship to the lacewings, while the structure towards the
apex recalls distinctly the venation of the Trichoptera.

,, 6. — Labium of Gryllus dumesticus, exhibiting the deep central
division. It should be observed that this organ is of a fleshy
character. The drawing is made from the upper or dorsal
surface.

Plate II.
Fig. 1. — The labium and pal[)i of Hemerobius, seen from beneath.
,, 2. — The same organs in tSialis lutaria, seen from above.

Journal of Microseopy 3'''^ Sep. Vol. 6. PI. 1

H C A.Vjne aa natdel

rphiihps. Sc.

Journal of Microscopy 3^^ Ser, Vol. 6. Pi. 2

Aa, ^.

\ f ? #V^

■ \ \ i / / /^

H C A. y/ne, ad nat del.

k

F.Phil:ips. Sc

SO^ucture of lahtuTn zn Ifeuroptera and (Trthcptera.

LEAVES FROM MY NOTE-BOOK. 45

Fig. 3. — The same organs in Agrion pnella.

,, 4. — The same organs in Lihellnla, seen from beneath.

,, 5. — The same organs in the Earwig, Forficnla auricularia, from
beneath.

The figures display the relative characters of the Labium
in the Neuroptera and the Orthoptera (see also Fig. 6 on
Plate I).

llca\)C6 from m^ IRote^BooF?.

(Bleanincjs from an ®l& Jfiel&.

By Alice Bodington, New Westminster, Canada.

IN the following paper, taken almost entirely from Darwin's
Aiiima/s and Plants 7mder Domestication^ I have been able
to choose only a few out of the innumerable interesting and
important examples of natural and artificial selection given in that
wonderful work. Indeed, the whole section dealing with variation
in' plants, and especially that part dealing with graft-hybrids, must
be left for another paper.

Everyone has heard of the Ancon breed of sheep, arising from
what (through our ignorance of its causes) is called a sport j but
the Niata breed of cattle, which one cannot doubt must also have
originated from a " sport " is not so well known.

Cattle.

On the Northern bank of the Plata a strange breed of cattle has
been developed known as "Niatas," and bearing much the same
relation to other cattle as bull and pug dogs do to other dogs. The
forehead is very short and broad, with the nasal end of the skull and
the whole plane of the upper molar teeth curved upwards. The lower
jaw projects beyond the upper, and has a corresponding curvature.
An almost similar conformation characterises the gigantic extinct
Sivatherium of India, but is not known in any other ruminant.
The upper lip of the Niata is much drawn back, the nostrils are
seated high up and are widely open, the eyes project outwards, and
the horns are large. In walking the horns are carried low, and
the neck is short. The exposed incisor teeth, short head, and up-

46 LEAVES FROM MY NOTE-BOOK.

turned nostrils, give these cattle a most ludicrous, self-confident
air of defiance. Many important anatomical variations occur in
the skull ; the lachrymal bone, for instance, articulates with the
premaxillary, and thus excludes the maxillary from any junction
with the nasal. In fact, hardly a bone of the skull presents the
same exact shape as that of the common ox.

So far back as 1760 these catde were kept as curiosities near
Buenos Ayres, and the race was believed to have originated with
the Indians southward of the Plata. In any case, however, the
divergence of race could not have begun further back than the
year 1552, when cattle were first introduced. The breed is very
true, and has lasted at least a century (Darwin writes in 1868). A
Niata bull and cow invariably produce Niata calves ; a Niata bull
crossed with a common cow and the reverse cross, yield offspring
having an intermediate character, but with the Niata peculiarities
strongly displayed.

When the pasture is tolerably long the Niatas feed as well as
common cattle with their tongue and palate ; but during the great
droughts, when so many animals perish on the Pampos, the Niatas
would, if not attended to, become extinct ; for the common cattle,
like horses, are able to keep alive by browsing with their lips on
the twigs of trees and on reeds. This the Niatas cannot .so well
do, as their lips do not join, and hence they are found to perish
before the common cattle. It shows also how natural selection
would have determined the rejection of the Niata modification, if
it had existed in a state of nature.*

Survival through Browsing on Twigs and Leaves.

Apropos of the faculty of keeping alive by browsing on leaves
and twigs, a lady friend on a ranch in British Columbia told me
they were waiting for a " wood cow." I wondered what particular
kind of animal this might be, when she explained that cattle
reared in a wooded district would thrive and even grow fat in the
" bush," where prairie cattle would starve. On a ranch at Hatzic
Prairie, the cattle accustomed to the country took to the woods
during one severe winter, and in the spring returned in good con-
dition, whilst the cattle which had remained on the prairie died in

* Animals and Plants under Domestication, Darwin, Vol. I., pp. 93-4.

LEAVES FROM MY NOTE-BOOK. 47

numbers from want of food. The Cariboo (the Canadian Rein-
deer) flock to the shelter of the woods during the long winters of
the Great North-West, and in the summer go to the shores of the
Arctic Ocean in search of their favourite lichen, the " Iceland
Moss " ; and doubtless this instinct has enabled them to survive
the extraordinary severe climatic conditions of this region.

Rabbits.

I will next give the account of the modifications, through the
action of the fresh environments, of certain rabbits which were
set loose on the Island of Porto Santo, near Madeira, in 141 8, by
J. Gonzales Zarco. Happening to have a female rabbit on board
which had [)roduced young during the voyage, he turned them all
out on the island. The animals increased so rapidly that they
actually caused the abandonment of the settlement. Thirty-seven
years after, Cada Mosto described them as innumerable ; nor is
this surprising, as the island was not inhabited by any beast of
prey, nor by any terrestrial mammal. At present, Porto Santo
rabbits differ conspicuously from European wild rabbits both in
colour and size. Whilst four wild English rabbits averaged 3 lbs.
5 ozs., one of the Porto Santo rabbits weighed only i lb 9 ozs.
They have decreased nearly three inches in length and almost half
in weight of body ; whilst in the Zoological Gardens they had a
remarkably different appearance to the common kind ; they were
extraordinarily wild and active, and many persons exclaimed on
seeing them that they were more like large rats than rabbits. They
were nocturnal to an unusual degree in their habits, and their
wildness was never in the least subdued ; so that Mr. Bartlett, the
superintendent of the Zoo, declared that he had never had a wilder
animal under his charge. This is a singular fact, considering that
these rabbits must have descended from a domesticated breed.

On enquiry as to whether these animals had been much hunted
by the inhabitants, or persecuted by hawks, or cats, etc., it appeared
this was not the case, and that no cause could be assigned for
their wildness. They live both on the central, higher rocky land,
and near the sea cliffs, and being exceedingly timid, seldom appear
in the lower and cultivated districts.

From numerous experiments carried on since Animals and

48

LEAVES FROM MY NOTE-BOOK.

Plants under Variation was published, one may conclude that the
small size of these rabbits results from great numbers depending
on a scant}' food supply. The necessity of looking out sharply for
themselves also accounts for the fact that the brain capacity of the
Porto Santo rabbits is very little less than that of the ordinary wild
rabbit. In this respect the large lop-eared domestic breeds rank
lowest ; the skull in these animals has increased in length, but with
a totally disproportionate weight of brain therein (see table, p. 133).
Darwin concludes that most naturalists, on observing these Porto
Santo rabbits with their reduced size, their fur, reddish above and
grey beneath, their tails and ears not tipped with black, and above
all the fact that they refused to couple with other rabbits, would
have ranked them as a different species. Yet these differences
certainly originated since the year i42o.''''

Dogs.

It is well known that dogs which have relapsed into a feral
state lose the habit of barking, this being a faculty apparently
depending on the companionship of man and consequent stimu-
lation of the dog's emotional and rational powers. Who that has
been attached to a spaniel has not noticed the almost painful
efforts these affectionate creatures make to express more feeling
than can be got into a bark ?

The Mackenzie River dogs of the Canis latrans type, when
brought to England, never learnt to bark properly ; but one born
in the Zoo " made his voice sound as loudly as any other dog of
the same age and size." Not only is the habit of barking quickly
regained by dogs which have lost that habit in the feral (relapsed)
state, but there is evidence that it can be acquired by both wolf
and jackal whelps in one generation. t

Some dogs which had run wild on Juan de Nova in the Indian
Ocean, entirely lost the faculty of barking, showed no inclination
for the company of other dogs, and did not acquire their voice
during a captivity of several months. On the island they congre-
gate in vast packs, and catch sea-birds with as much address as
foxes could display. In New Guinea and Tierra del Fuego the

* Ibid., 117 — 20, Table of skull and brain measurements, p. 113.

t Ibid., pp. 27 — 8.

LEAVES FROM MY NOTE-BOOK. 49

dogs show a ready adaptation to circumstances by catching crabs
and fish in the tidal pools in the rocky coast. They will turn over
the stones on the shore to catch the crustaceans which lie beneath,
and " are clever enough to knock off the shell-fish at a first blow,"
for if this be not done shell-fish are well known to have an almost
invincible power of adhesion.*

Alteration of Mental and Physical Characteristics

BY Climate.

In India the climate directly modifies the forms of dogs, and
even their mental and moral qualities. Several of our English
breeds cannot live -in India, and it is positively stated that when
bred there they degenerate, not only in their mental faculties, but
in form. Captain Williamson, who carefully attended to this
subject, states that " hounds are the most rapid in their decline ;
greyhounds and pointers also rapidly decline." Dr. Falconer states
that bulldogs which have been known, when first brought into the
country, to pin down even an elephant by its trunk, not only fall
off in two or three generations in pluck and ferocity, but lose the
underhung character of their lower jaws ; their muzzles become
finer, and their bodies lighter. The Rev. R. Everest obtained a
pair of setters born in India, which perfectly resembled their
Scotch parents ; he raised several litters from them in Delhi,
taking most stringent precautions to prevent a cross ; but he never
succeeded, though this was only the second generation in India, in
obtaining a single young dog like its parents in size and make ;
their nostrils were more contracted, their noses more pointed, their
size inferior, and their limbs more slender.

Degenerative changes even more pronounced are mentioned
as occurring in dogs on the coast of Guinea. According to
Bosman, " they alter strangely ; their ears grow long and stiff like
those of foxes, to which colour they also incline ; so that in three
or four years they degenerate into very ugly creatures ; and in
three or four broods their barking changes into a howl.t

I will just mention, before leaving the subject of the dog, the
curious case of a mental quality remaining where outward physical

* p. 41-
\Ibid., pp. 39—4.

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. e

50 LEAVES FROM MY NOTE-BOOK.

characteristics have disappeared. Lord Orford, as is well known,
crossed his famous greyhounds, which failed in courage with a
bulldog ; and "after the sixth or seventh generation," says Youatt,
" there was not a vestige left of the form of the bulldog, but his
courage and indomitable perseverance remained." This inherit-
ance of mental qualities is perhaps not so extraordinary in an
animal which shows itself capable of such development of brain
as does the dog. "Some dogs' brains are high and rounded," says
Dr. Burt Wilder, "whilst others are long, low, and narrow in front.
In the latter the olfactory lobes are visible for about half their
extent, when the brain is seen from above, but they are ivholly con-
cealed by the hemispheres in other breeds.*

DuCKS.t

The duck has been comparatively a late arrival amongst
domesticated auimals ; it was not known to the ancient Egyptians,
the Jews of the Old Testament, or the Greeks of the Homeric
period; indeed, the tame duck was not known to Aristotle. About
eighteen centuries ago, Columella and Varro speak of the necessity
of keeping ducks in netted enclosures like other wild fowl, so that
even at this period there was danger of them flying away. As
Columella advises those persons who wish to increase their stock
of ducks to collect the eggs of wild birds and place them under a
hen, it is evident that the duck had not yet become a naturalised
and prolific inmate of the Roman poultry yard.

An interesting experiment was made by Mr. Hewitt in trying
the effect of domestication on the wild duck. \ His experience
differed from that of Tiburtius in Sweden, who, after rearing wild
ducks for three generations, found they did not vary even in a
single feather. Mr. Hewitt, on the contrary, found that his young
birds always changed and deteriorated in character in the course
of two or three generations, notwithstanding that great care was
taken to prevent them from crossing with tame ducks. After the
third generation his birds lost the elegant carriage of the wild
species, and began to acquire the gait of the common duck. The

* lbid.,^Z^.

t pp. 291—93.

X journal of Horticulture, 1862, p. 773, and 1863. p. 39.

LEAVES FROM MY NOTE-BOOK. 51

white collar round the neck of the mallard became broader and
less regular, and some of the long primary wing feathers became
more or less white. When this occurred, Mr. Hewitt destroyed
nearly the whole of his stock, and procured fresh eggs from wild
nests ; so that he never bred from the same family for more than
five or six generations. It seems strange that he was not curious
to see the further result of his experiment. His birds continued
to pair together, and never became polygamous, like the common
domestic duck. I presume that the expression " deterioration "
must be meant to apply to the profound mental and moral deteri-
oration of the domesticated duck, since Mr. Hewitt's semi-tamed
wild ducks increased in size. Woefully has civilisation changed
the habits of the tame duck from this idyllic picture of its wild
cousins.

" The Wild Duck pairs very early in the year, the period being
somewhat delayed by hard weather and the ceremonies of court-
ship, which require some little time. Soon after these are performed
the respective couples separate in search of suitable nesting places.
The spot chosen is often near a river or pond, but often very far
removed from water ; and it may be under a furze bush or a dry
heath, at the bottom of a thick hedge-row, or even in any conve-
nient hole in a tree. A little dry grass is generally collected, and
on it the eggs, from nine to eleven in number, are laid. As soon
as she begins to sit, the mother begins to divest herself of the
down which grows thickly beneath her breast feathers, so that the
eggs are deeply embedded in this heat-retaining substance — a por-
tion of which she is always careful to pull, as a coverlet, over her
treasures when she quits them for food. She is seldom absent
from the nest but once, or perhaps twice, a day, and then she dare
not leave it till her mate has assured her she may do so unob-
served. Joining him, the pair resort to some quiet spot, where
she may bathe and otherwise refresh herself. Then they return to
the nest, and after cautiously reconnoitrmg the neighbourhood, she
reseats herself on her eggs, while her mate, when she is settled,
repairs again to the water, and passes his time listlessly in the
company of his brethren, who have the same duties, hopes, and
cares. Short and infrequent as are the absences of the duck
during incubation, they become shorter and more infrequent

52 LEAVES FROM MY NOTE-BOOK.

towards its close, and for the last day or two it is probable that
she will not stir from the nest at all. When the' eggs are hatched,
her next care is to get her brood safely to the water. This, when
the distance is considerable, necessarily demands great caution,
and so cunningly is it done that but few persons have encountered
the mother and offspring as they make the dangerous journey.
(When Ducks breed in trees, as is often the case in the London
parks, it is still a mystery how the young are conveyed to the
ground.) If disturbed, the young immediately hide as they best
can, while the mother quacks loudly, feigns lameness, and flutters
off to divert the attention of intruders from the brood, who lie
motionless at her warning notes. Throughout the summer the
Duck continues her care unremittingly, until her young are full
grown and feathered."*

The deterioration of instinct brought about by civilisation is
often painful to witness. Not only is the instinct of nest-making
lost, but the eggs are dropped in any place where the bird may
happen to be ; in the dust of the poultry yard, or in a pond.
Persons who wish to rear ducks profitably are therefore accustomed
to shut them up in their pens till after laying. One duck I had
hatched some young ones on her own account, but the maternal
instinct, except for sitting, was dead; she deserted her young ones,
which endeavoured wearily to follow her, and when they were
placed in a coop with her she endeavoured to kill them. But
most of the ducks I had did not attempt even to sit. In one
duck, who from a remote resemblance to the Aylesbury breed was
known as the Marchioness, maternal instinct by a species of
atavism was healthy. Year after year the Marchioness made her
nest where none of us could even find it, and came in followed by
a brood of five young ducks, which she watched over with the
fiercest vigilance.

Call Ducks.

Darwin, speaking of the Call Duck, gives an instance of trans-
mission of a quality peculiar to the female of this variety, through
the male. He says, " Call Ducks are remarkable for their extra-
ordinary loquacity : the drake only hisses like common drakes ;

Article Duck, Encyclopedia Britannica.

LEAVES FROM MY NOTE-BOOK. 53

nevertheless, when paired with the common duck, he transmits to
his female offspring a strong quacking tendency." '''

Correlation of Growth.

Speaking of the correlation of variations, Darwin describes, at
great length, the extraordinary osteological changes in the skulls of
crested fowls ; beginning in the black boned silk fowl with a very
small crest, and the skull penetrated only by a few minute orifices ;
and culminating in fowls which, with a largely developed crest,
have a largely protuberant skull, perforated by a multitude of
irregular open spaces, and containing a portion of the brain sub-
stance. He adds, " There can be no doubt that in former times
the breeders of Polish fowls attended solely to the crest, and not
to the skull ; nevertheless, by increasing the crest, he has uninten-
tionally made the skull prominent to an astonishing degree ; and,
through correlation of growth, he has, at the same time, affected
the form and relative connection of the premaxillary and nasal
bones, the shape of the orifice of the nose, the breadth of the
frontal bones, the shape of tlie post-lateral processes on the frontal
and squamosal bones, the direction of the axis of the long cavity
of the ear, and lastly, the internal configuration of the whole
skull, together with the shape of the brain."

Darwin gives numerous instances of breeds of animals and
varieties of plants originating from "sports," and uses the expression
that the variations " arose suddenly." Paleontology leads one to
infer that differentiation of species has arisen by slow and almost
imperceptible degrees, and this seems to be the usual course of
evolution ; but, on the other hand, we have a great weight of first-
hand evidence as to the origination of fresh breeds by sudden
variations.

I will take one case, that of the Black Peacock. Sir R. Heron
states that this breed suddenly appeared, within his memory, in
Lord Brownlow's large stock of pied, white, and common peacocks,
and in Mr. Thornton's stock of common and pied peacocks. It
is remarkable that in these two latter instances the black-shouldered
kind, though a smaller and weaker bird, increased " to the extinc-
tion of the previously existing breed." No less than seven well

* Vol. I., pp. 295 — 6. Ibid., p. 279.

54 LEAVES FROM MY NOTE-BOOK.

authenticated cases have occurred in Great Britain of japanned
birds having suddenly appeared, within recent times, in flocks of
the common peacock. Mr. Sclater, a high authority, imagined
that these black peacocks were a reversion to some breed which
would hereafter be discovered in a wild state; but as no wild birds
of this description have ever been found, we may consider these
japanned peacocks demonstrate one of nature's ways of producing
a new species.*

The constitutional strength of the young japanned peacocks,
which led to the extinction of the lighter varieties, is parallelled in
many other instances by the increased constitutional strength of
many other dark animals. Professor Wyman informed Darwin
that " being surprised to find all the Pigs in one part of Virginia
black, he made enquiries, and ascertained that these animals fed
on the roots of the Lach?iant/ies tinctoria, which colours their
bones pink, and, excepting in the case of the black varieties, causes
their hoofs to drop off." The squatters therefore chose only black
pigs out of a litter for raising, as they alone had a good chance of
living. In the Tarentino the inhabitants keep black sheep alone,
because the Hypericum crispum abounds there, and this plant does
not injure black sheep, but kills the white ones in about a fort-
night's time. And similar deep constitutional differences, with
regard to susceptibility to certain diseases, is found in the dark and
light varieties of man.

Throughout the two volumes of Animals and Plants under
Domestication, one sees it was Darwtn's task to prove, by over-
whelming cumulative evidence, that an accumulation of variations
under natural or artificial selection could lead to the formation of
new species. His work was not to examine hoiv variations arise ;
but this still deeply mysterious question is the one of chief impor-
tance to the present generation, to whom the fact of the evolution
of species, which Darwin laboured to establish, is a truism.

I have had room to give only a very few of the wealth of
interesting facts in this wonderful work of Darwin ; and I must
leave the evidence as to Graft-Hybrids, perhaps at this day the
most interesting and important of all, for another paper.

* Ibid., pp. 305—6, Vol. II., p. 212, 329—31.

[ 55 ]

British Ib^bracbniba^, cm*

By Charles D. Soar. PI. III.
THE GENUS HYDRACHNA (0. F. Miiller, 1781).

BODY, nearly circular in shape, soft and easily broken ; legs,
short, hairy, and adapted for swimming ; all the tarsi have
claws ; epimera forms two groups on each side ; mandibles
joined together, forming a beak, which under the microscope can
be seen to be lancet-shaped ; palpi, tolerably long, the third joint
being the longest.

Miiller, in his work on Water-Mites, published in 1781, des-
cribes and figures forty-nine species of Hydrachna, using a specific
name only to distinguish one form from another. Since then the
family of Hydrachnidce has been divided into twenty distinct
genera, the name Hydrachna being retained for the genus we are
now considering, the characteristics of which are given above.
Duges was, I believe, the first to restrict this genus to those mites
possessing a beak, Koch, in his work, Deutschlands Crust., etc.,
describes and figures five species, viz. : — H. geographica, H.
t/npressa, H. globosa, H. cruenta, and II. pufiicea. Neuman des-
cribes only two.

I have not yet had an opportunity of observing the transition
of any of these from the egg to the imago ; but it has been
observed and described by other writers. The eggs are laid in the
spring on the stems and leaves of aquatic plants ; in a few days
these are hatched out. The larvae when hatched are hexapod,
with a large heart-shaped sucker in front, which might be taken for
the head ; but the eyes are situated behind on the anterior margin
of the body. In this stage they attach themselves to different
species of water insects, such as Nepa, Dytiscus marginalise etc.

Several times in the pages of the earlier volumes of Science
Gossip may be found the query. What are the blood-red, pear-
shaped parasites firmly attached to the under part of the head of
the male Dytiscus} On page 255 oi Science Gossip, Vol. I., Lewis
G. Mills gives a figure of one found by him, which is no doubt the
larval form of a species of Hydrachna. After having spent a
certain time as a parasite on some other living object, they no

56 BRITISH HYDRACHNID^.

doubt turn into the perfect mite. A short time ago a Quekett man
was surprised to find, on examining a Dytiscus marginalis which
he had preserved in spirit some time before, a perfect mite (genus
Bydrachna), partly emerged from the body of the beetle. As I
have not seen it, I cannot say what species it was. I am inclined
to think that, when this subject has been more studied, the same
species of mite will always be found on the same species of
water insect. As a typical species of Bydrachna, I propose to
describe and illustrate Hydrachna geographica (Miiller).

Bibliography.
1 78 1. — Hydrachna geographica. Miiller, Hydrachna, etc., p. 59,

Tab. viii., Figs. 3, 4, 5.
1793. — Trombidmtn geographicwn . J. C. Fabricius, Ent. Sysf.,

Tom. 11., p. 405, N. 32.
1835-41. — Hydrachna geographica. C. L. Koch, Deutschlands

Crust., etc.. Haft. 14, Fig. 13.
i^']^.— Hydrachna geographica. Neuman, Sveriges Hydrachnider,

p. Ill, Tab. xiv.. Fig. 2.

This species is, I believe, the largest of the water mites, speci-
mens having been found measuring as much as one-third of an
inch in length.

The female from which this drawing was made is about one-
fifth of an inch long. Body nearly circular, black and red in
colour. On the dorsal side are eight spots, or pores, arranged in
two rows, as shown in the drawing. Legs red, with yellow joints.
In some drawings which I have seen of this mite, the legs are
shown as black with red joints ; but those which I have examined
have not been so. The first pair of legs are without swimming-
hairs. It is a very beautiful mite alive, and is a powerful swimmer.

The male is pear-shaped, and a little smaller than the female.
I have not at present been able to detect any difference in the
sexes. The male of H. geographica has not the peculiar process
on the fourth pair of legs nor the modified third pair of feet met
with in males of other species of Hydrachna, as described in the
previous papers on this subject. Both these mites were taken by
me at Snaresbrook on March 23rd, 1895, on one of the excur-
sions of the Quekett Microscopical Club. I believe this is the
first time the male has been figured.

Journal of Microscopy 3^^ Ser. Vol. 6, PL3.

//J, \ |Wn J / k\-'/

! I '^^

I '■'/'

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sm,

"€ ''^ A^*^ t/- .r-nt. .,:c:i, \

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IfT^drachna aeoaraphica.

r Phillips. Sc

THE ORIGIN OF INSECT TRANSFORMATIONS. 57

EXPLANATION OF PLATE III.

Fig. 1. — Dorsal view of female.
,, 2. —Ventral view ,,

,, 3. — Dorsal view of male.
,, 4. — Ventral view ,,

,, 5. — Palpi and mandibles.

^be QviQin of 3necct ZTran^formatione.

By G. H. Bryan, M.A., F.R.S.

AT the Ipswich meeting of the British Association, Prof. C.
L. Miall, F.R.S. , of the Yorkshire College, Leeds, read a
most interesting paper on this subject, and it has occurred
to me that a brief account of Prof. Miall's views might be accept-
able to the readers of \h.Q. Journal of Microscopy.

The subject was dealt with twenty-one years ago by Sir John
Lubbock in his well-known little book, published in the Nature
series ; but since the appearance of that work many new facts
have been discovered which necessitate some modifications of the
conclusions then arrived at by him.

The primary object from which all animal metamorphoses owe
their origin is the facilitation of dispersal, and at one time it was
thought that some analogy existed between the transformations of
insects and those of many marine animals, such as the Echinoder-
mata and the Common Limpet. Prof. Miall considers the two
classes of transformations to be radically different in their nature.

It will be noticed that both transformations result from a divi-
sion of labour in the two operations of feeding and dispersal, but
in the marine animals dispersal takes place first, and feeding
second ; while the insects feed in their early stages and only
become adapted to dispersal in their final stage. For this reason,
the transformations of the Echinodermata may be called Larval
Transformations,, since they take place before the animal has
grown and developed, while those of the insects may be distin-
guished as Adult Transformations. A closer parallel to insect
transformations exists in the amphibia. Thus, in the tadpole

58 THE ORIGIN OF

Stage of the common frog, the animal grows and developes, while
it is not till the final stage that it becomes adapted for migrating
from one pond to another.

In the birds we have an instance in which the operations of
feeding and dispersal are performed simultaneously, and conse-
quently no metamorphoses are required.

The reason for the peculiar transformations of the marine
animals can be traced to the conditions under which they live.
In the ovum, the yolk is scanty by reason of the great number of
eggs produced ; and this, again, is necessitated by the extraordinary
risks to which the animals are liable, especially where the sea is
shallow. Another cause consists in the heavy armour with which
the adult Echinodermata are protected and which would render
migration impossible, or at any rate very difficult. Again, marine
animals are more easily dispersed by currents when they are small ;
consequently, the means of locomotion are eminently suitable for
an animal in its early incomplete stages.

In the insects it is just the reverse. The mechanical difficult-
ies connected with the operation of flying can only be overcome
by an animal in its mature stage, and the same thing applies to
the amphibia, which for the purposes of dispersal require to be
capable of locomotion both on land and in water, a combination
which is naturally most easy of attainment in the mature state.
Thus, the operation of migration is naturally performed by the
adult animal and that of feeding by the larva, The result of this
division of labour is to cause the larva to degenerate. In propor-
tion as the adult becomes more and more highly developed, the
larva sinks lower and lower and loses its active organs, until we
come to larvEe which consist of little more than a soft, flabby sac,
furnished with jaws, or, going still further down in the scale, we
find that in the larva of the blow-fly even these jaws are replaced
by mere hooks.

The type of the primitive insect, according to Fritz Miiller, was
very much like some of the present wingless orthoptera. Accord-
ing to Brauer and Lubbock, the nearest modern approach to the
ancestral type is represented by Campodea. The larvae of certain
carnivorous beetles are very similar to this type. Regarding the
wings of primitive insects, it is remarkable that many insects in

INSECT TRANSFORMATIONS. 59

the embryo stage show traces of three pairs of wings as well as
three pairs of legs, and it therefore seems probable that the front
pair were not retained because they were too far away from the
insect's centre of gravity. The breathing trumpet of the pupa of
the gnat is probably a modified form of these appendages. In
certain fossil insects these " prothoracic wings are well developed,"
and according to Broginart this is notably the case in certain
palaeozoic insects from the Coal Measures.

The pupal stage of insects is unique, and has no parallel in
any other division of the animal kingdom. It has been suggested
that the necessity for this stage originated in the changes which
the mouth parts undergo. This explanation is insufficient, because
many insects which pass through a quiescent pupal stage do not
change their food in passing from the larval to the imago stage.
Sir John Lubbock has suggested that the pupal stage is a conse-
quence of the immature condition of the larva at the time of its
birth ; and Brauer has pointed out in confirmation of this theory
that insects which have large eggs are not generally quiescent as
pupae. But there are exceptions to this rule ; moreover, the pupa
is too remote from the larval stage for the conditions at its time of
birth to have much influence on it then. Again, in many cases,
the larva in the egg positively retrogrades, so that at the time of
hatching it has degenerated from its form in the earlier stages of
the egg.

A more hkely explanation is that pupation is a consequence of
this very degeneration of the larva. As the imago developes, the
larva degenerates, and extremes thus recede until a resting stage
is required for the regeneration of the insect. Thus, the blow-fly
is a highly-developed insect, but its larva is little more than a
digestive sac, furnished with hooks, which, as above mentioned,
take the place of proper jaws.

The divergence between the larva and imago state is in many
insects doubtless partly due to their honey-sucking habits. Of all
insects, the bees have been the most influenced in this respect by
flowers ; lepidoptera come next ; and many diptera are also honey-
suckers. Not only have insects played a prominent part in the
development of flowers, but the juices of flowers have formed an
important article of food to insects, the more so as honey can be

60 THE ORIGIN OF INSECT TRANSFORMATIONS.

Stored without undergoing putrefaction. This storage of honey
has caused further degeneration, which has cost the larva of the
bee its legs ; these, being no longer required to enable it to reach
its food, have disappeared.

Ants form a remarkable exception among the hymenoptera in
the matter of gathering honey, but even they show the same pro-
pensity for sweet juices in a slightly different form, in their habit of
keeping aphides as cows from which they suck the honeydew.

The suddenness of the change from larva to pupa and from
pupa to imago is probably caused by the hard integument of many
insects, which does not admit of gradual changes taking place. A
sudden change has thus taken place at the time of moulting, and
with the gradual divergence between the larval and imago states
this change has become more marked, and has necessitated the
intervention of a quiescent pupal stage. A notable exception
occurs in Melee, which in its first stage is active, and subsequently
becomes more like a maggot.

To sum up, then, the separation of the functions of nutrition
and locomotion has caused insects to become more highly deve-
loped in their final stage and to degenerate in their early stage.
The hardness of their integument has necessitated the transforma-
tions taking place at the times of moulting, and the difference
between the larva and imago has at last become so marked that
the intervention of a quiescent pupal stage has become the only
possible means of bridging over the gap.

Growth of Trees. — The following interesting results of expe-
riments relating to the growth of trees at various times of the day
have been sent to us by Mr. E. H. Thompson, the Government
Entomologist of Tasmania. Measurements were taken as far as
possible every three hours, with the following results :^ — From 6a.m.
to 9 a.m., 8f per cent, of growth; from 9 a.m. to noon, \\ per
cent, of growth; from noon to 3 p.m., no growth; from 3 p.m.
to 6 p.m., no growth ; from 6 p.m. to 9 p.m., i^ per cent, of growth ;
from 9 p.m. to 12 p.m., 3^ per cent, of growth ; from 12 p.m. to
6 a.m., 85 per cent, of growth. The greatest growths in twenty-four
hours were : — Banksia Rose, 6^ in. ; Geranium, 5f in. ; Wattle,
4^ in. ; Apple, 2\ in. ; and Pear, i^ in. — Public Opinion.

[ 61 ]

Some B^aptation of Mater plantd to
tbeir lEnvironment.

By W. Falconer.

WATER plays such an all-important part in the growth and
economy of every organism that no surprise is felt either
at the abundance or variety of vegetable life found in
moist situations ; and when we note the habitats selected by the
various plants, the banks clothed with flowers, grasses, and sedges
in tangled confusion, the shallow waters of the edge in which grow
many familiar floral' types, and the deeper central waters in which
other forms flourish, and note, also, the conditions under which
they grow, so diverse and so different to those which obtain in the
case of land-plants, one naturally expects much differentiation of
structure due to environment, and the acquisition of new habits
to meet the altered circumstances under which each must perfect
its seed, reproduce its kind, and obtain the air and light necessary
to a healthy and continued existence. Nor is our expectation
disappointed, and in pursuing our inquiries into the subject it
becomes a matter of some difficulty to select from the wealth of
material at our disposal typical exemplifications of the now
accepted principles of scientific investigation, inaugurated by
Darwin and Wallace. I propose, within the limits of the space
allotted to this paper, to deal with a few characteristic adaptations
of water-plants to their surroundings which are of general interest.
I. — We observe in them a deficiency as well as a different
arrangement of the strengthening or woody tissue, which gives
mechanical support to stems and other structures. In a land-
plant, the bundles of this material are arranged towards the peri-
phery of the stem, in which position they are most advantageously
disposed to withstand the varied and constant strains to which
they are exposed, and which are mainly lateral, arising chiefly from
the action of winds which blow in a lateral direction. The
organism has, by this provision of nature, sufficient strength in
itself to endure the strife of the elements, and so escapes destruc-
tion. By way of illustration, and from the point of view of an
engineer, we might compare the plant to the cylindrical iron sup-

62 SOME ADAPTATION OF WATER-PLANTS

porting pillar of a bridge, which, in accordance with well-known
mechanical principles, is hollowed in order to throw all the strength
to the outside, the better to resist any lateral strain, and which
may be filled with cement in order to sustain a more crushing
weight. But from the very nature of its environment, a hydro-
phyte is protected from winds, and hence from lateral strains. Its
parts float freely, and rise and fall with the waters or move hither
and thither in obedience to currents. The only force, therefore,
that can be brought to bear upon the plant in this situation is a
puUing one. In still water, where there are no currents, and the
only turmoil is that temporarily caused by the movement of some
animal organism or by the breeze, the innate recuperative power
and cohesive force of the cell-walls of the freely floating portions
is sufficient protection for the plant ; but in running water some-
thing more than this is needed, and the tissues become flexible
and tougher and their walls thickened.

In any case as compared with land-plants, the bundles become
fewer in number, and have a tendency to assume an axial position
(see T.S. of Villarsia), Neither do the component cells become
lignified to the same extent, as the absence of any great strain
relieves the plant from the necessity of making what would, under
the circumstances, be useless tissue. As a further illustration of
the mechanical importance of the central grouping of the fibro-
vascular bundles, take the analogous case of a root. A root, apart
from the pressure exerted by the superincumbent soil, is liable
only to the pulling or longitudinal strain caused by the bending
and swaying of the stem, in these respects resembling a hydrophyte.
The strain to be resisted, however, is very much greater, and the
structural arrangement best adapted to meet it is the central
grouping of the resisting forces, as has been proved in practice by
man, who uses the same means to obtain the same ends. Under
parallel circumstances, the aquatic stem and a root develop an
approximately similar structure, so far, at least, as the grouping of
the bundles is concerned.

In addition to the adaptation just mentioned, water-plants have,
in various parts of their other tissues, in leaf and stem and petiole,
numerous air-spaces which are not to be confounded with similar
cavities in the hollow stems of Equisetum grasses and UrnbelUferce.

TO THEIR ENVIRONMENT. 63

In the latter, they are produced by the drying-up of masses of
tissue, as is shown by ragged edges of cell-walls remaining after
the drying-up process ; and in the former, by the clean separation
of the walls dividing cells, such fringes being absent. These air-
spaces, which, when the plant is in a healthy state, are filled with a
mixture of gases, practically the same as atmospheric air, and from
which it may obtain supplies of carbonic acid, buoy up aquatic
plants in the water, and effectually secure mechanical support to
them, so that, after all, the non-lignification of cells is really an
advantage to such organisms, owing to the greater lightness thus
obtained by the reduction of the strengthening strands. This
altered structural formation is more clearly shown in those plants
which are totally submerged. For example, Anacharis, Hottonia
palustris, and Uiriadaria are much more thoroughly aquatic types
than Hippuris, Nuphar luteum^ and ATyniphc^a alba. French
savants have experimented with normally terrestrial plants, grow-
ing them in water, and in doing so have educed another proof of
the great influence of environment on plant tissues. Under these
circumstances, any new growths were found to assume the aquatic
type of structure.

II. ^-A plant obtains its chief food, carbon, from a gas, carbon
dioxide (a compound of carbon) and oxygen, which is present in
the air, being provided with little mouths or stomata, through
which the gas has access to the internal tissues, where the chloro-
phyll or green colouring matter of the cells, in the presence of
water, decomposes it, fixing the carbon and restoring the oxygen
to the atmosphere. Many of the vital operations in the plant's
economy — such as the decomposition of the carbon dioxide and
the expulsion of the oxygen already mentioned, the formation of
chlorophyll, and the transmutation of the crude sap and the
carbon into food material for the plant — can only be carried on
under the influence of light.

It is not, therefore, difficult to comprehend that a plant or a
portion of a plant, growing immersed, must undergo modifications
of structure to enable it, under the changed conditions of its life,
to get its due share of light and air. The submerged leaves,
accordingly, become much divided, in order to allow a ready
passage to rays of light, and to enable the plant to extend its

64 THE ADAPTATION OF WATER-PLANTS

operations through a greater area of the fluid from which it derives
its suppUes of carbon dioxide, as in Ranunculus aquatiiis, Hottonia,
Utricularia, and Myriophyllutn. In other plants whose submerged
leaves approach in size and shape the terrestrial type, as in Ana-
charts, Potamogetoji crispus, P. densus, and P. perfoliatus, the same
ends are subserved by the translucency of these organs, together
with their comparative smallness and greater number. Moreover,
many of them grow in slow-running streams, and their flexible
stems permit them to assume a sloping position, so that the upper
leaves shut out little or no light from the lower ones. Submerged
leaves have no stomata, the carbon dioxide which they require for
food being absorbed directly from and with the surrounding water,
or in combination with calcium as bicarbonate of lime, the latter
salt being in solution and having a higher percentage composition
of its component carbonic acid than monocarbonate of lime
(CaCog), from which it has been formed. A number of hydro-
phytes, including Myriophylliim, Ceratophyllum, Ranunculus aqua-
tiiis, and several species of pond weeds, are capable of absorbing
from the bicarbonate this extra portion of carbonic acid, leaving
the nearly insoluble (in water) monocarbonate as an incrustation
on the stems and leaves.

In some cases, the lime, in addition to forming in this way an
external coating to the cell-wall, permeates its substance as well.
Apart from its geological importance as a factor in the formation
of calcareous beds, consequent on the death and decay of a suc-
cession of such vegetable growths, the precipitated lime acts as a
further protection to the tender tissues of the living plants. Float-
ing leaves are, as a rule, entire (e.g., NyinphcBa, Nuphar, Villarsia,
Hydrocharis), and have no stomata on their lower surface, where
they are in contact with the fluid, but have abundance on the
upper surface, which is exposed to the air.

Aerial leaves, which are lifted entirely out of the water, are
usually erect, and have the stomata pretty equally distributed on
both surfaces (water-flag, grasses, and sedges). The water butter-
cup {Ranunculus aquatiiis), already cited as an example, strikingly
illustrates the various types of leaves characteristic of aquatic
plants. Some varieties of it have all the leaves submerged and all
finely divided ; others have both submerged and floating leaves,

TO THEIR ENVIRONMENT. 65

the submerged again being finely divided and the floating ones
entire ; while on mud the plant produces only entire leaves.

III. — When we make a comprehensive survey of the various
genera and species of aquatic plants, we find that the greater
number of them have only their lower parts immersed in water
(Nymp/uea, Nuphar, various UmbellifercB, Alisma, Sparganium,
Typha, etc.), while comparatively few are totally submerged
{Ruppa, various Potamogetons, Myriophyllum, Anacharis), and
fewer still float freely without attachment. The first cannot live if
wholly immersed for any length of time, and the two last if they
are removed from the watery medium which surrounds them and
exposed to the air.

The unattached plants usually grow in quiet pools and ditches,
and are therefore not subject to any great displacement. Some of
them {Lemna polyrhiza, L. gibba, L. minor) possess roots, and
others {Le?nna trisiilca, Cerafophyllum, Utricularia, Hottonia) none
at all. Those provided with roots, when left on moist earth, can
still exist, being capable of absorbing food from the ground by
these appendages in the same manner as a land-plant, but, under
the same adverse conditions, the less perfectly equipped rootless
plants perish.

Some of the partially immersed plants (reeds, rushes, water-
lilies) may have their submerged parts bared by the retreating water
without injury, as they will continue to thrive just as well on the
wet earth, their leaves being adapted to live an aerial life. In
others {Potamogeton natans, P. heterophyllus, Ranunculus aquatilis)
which have both submerged and floating leaves, when thus stranded,
the submerged leaves alone decay, as their structure renders them
incapable of absorbing carbon-dioxide from the atmosphere itself,
but the floating leaves continue to thrive, and any new leaves
produced conform to the shape of the hitherto floating ones.

The cause of these phenomena is to be looked for in the
structural differences of the parts. The cellulose, the substance
of which the cell-wall largely consists, becomes in the aerial por-
tions of plants corky, very elastic, and nearly impermeable to
water, or cuticularised, as it is termed. This modified cellulose is
highly important to the plant, as it prevents excessive loss of water
by evaporation through the cell-wall. In hydrophytes, the epider-

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. f

6Q SOME ADAPTATION OF WATER PLANTS, ETC.

mis is not differentiated in this manner, as there is no danger to
them, by very reason of their environment, of any loss of the
precious fluid ; but as the latter, with its contained food-salts,
enters them through their whole surface, it is necessary for their
epidermis to have absorptive powers. Consequently, there is no
thickening or cuticularisation of the submerged external walls, the
cells are conterminous everywhere, leaving no openings and
forming an excellent absorptive surface, no organs being needed
either for the conduction or transpiration of water.

The amount of transpiration also varies with the temperature
and climate. In very hot countries where the loss of water by
evaporation is correspondingly great, the cuticle is markedly evi-
dent, consisting of several layers of cells, this formation being well
seen in J^i'cus e/asfica, the India-rubber plant. In plants growing
in temperate regions in damp places, the quantity of this tissue is
considerably less, and where it is remarkably so transpiration
takes place very readily. For this reason, trees like willows are
planted in bogs to dry up the moisture in them.

Another specialisation of the cellulose is to be found in sea-
weeds. In them there is no epidermis, but the cells towards the
periphery are crowded together, and the cell-walls, generally,
become mucilaginous. When the tide recedes and leaves the
algae exposed, tbe mucilage hardens, giving them the horny
appearance with which we are all familiar, when by any mischance
they are withdrawn from their native element. The hardened
mucilage prevents dessication of the protoplasm or living principle
of the cells, and thus preserves the plant alive and intact. On
being again covered with water, the mucilage readily absorbs the
liquid, and immediately becomes softened and absorptive again,
and the plant is restored to full vigour of life, having suffered no
injury from its temporary embarrassment.

IV. — There are present in water, in addition to the carbon
dioxide already spoken of, other salts that are essential to the
well-being of the plant which are in a state of solution, and which
enter the organism in the same manner. It might, then, be
thought of advantage to a plant to fix itself in fast-running water,
where a constant, ever-changing, and plentiful food supply would
be presented to it. This is, however, far from being the case, and

ON THE STRUCTURE OF THE ROOT. 67

there is great poverty of floral types in rapidly-flowing waters,
compared with their abundance in still and quiet waters. Nor is
the reason of this far to seek. All the particles in the water at
the same place move at the same rapid rate, and it is impossible
for a plant to select and absorb its food when placed under the
resulting mechanical disadvantage, as sufficient time is not allowed
for the act of absorption to take place. Moreover, even if this
necessary act could be performed under the circumstances, it is a
well-ascertained fact that water from natural sources contains a
scarcity of those salts which can be assimilated by the plant as
food.

®n the Structure of tbe IRoot.

By Harold Wager, F.L.S.,

AND

Norman Walker,
Assistant in the Biological Laboratory^ Yorkshire College.^

Plate IV.

THE roots of plants perform two functions. First, they fix
the plant firmly in the soil and keep it upright ; and second,

they absorb food substances in the form of water contain-
ing mineral salts in solution. We shall appreciate the importance
of the root when we remember that a plant is largely made up of
water in one form or another, for all the solid material in the plant
consists of water in combination with other substances, and a
large amount of what may be called free water fills up the
numerous spaces which occur in this solid structure. Now, very
little, if any, water is absorbed by any part of the plant except
the root. The water thus absorbed is ultimately carried upwards
to all parts of the plant.

Furthermore, as the leaves absorb a certain kind of food —
carbonic acid gas — from the air, which food is transformed by a
series of chemical changes, first into sugar, then starch, and then
again into sugar, in which form it is dissolved and distributed to
other parts of the plant where such food is required, we must,

* Paper read to the Leeds Naturalists' Club on Nov. i, 1895.

68 ON THE STRUCTURE OF THE ROOT.

therefore, enquire into the structures by which this food material
is carried downwards in the root.

We have, therefore, in the examination of a typical root, to
see if we can determine by what special structures, if any, the
following kinds of work are done : —

I. — Fixture and support of plant.

2. — Absorption of water.

3. — Conduction of water and food upwards.

4. — Conduction of food materials downwards.

We may obtain roots for examination in two ways. We may
dig up roots growing in the soil, or we may plant seeds in sawdust
and use the coots of the seedlings. The latter is the simpler and
for many purposes the best method, as it is often difficult to clear
roots obtained in the former way of all the particles of soil that
adhere to them. As, however, the roots of seedlings have been
well described in text-books, I propose to take a root that is not
so well known, namely — that of the Common Lime, Tilia Europea.

The material is best obtained by digging up roots of a lime,
and selecting those roots which have not had their apices broken
off. Let us take one of the branches about the size of a knitting
needle and examine its appearance. It is brownish in colour, and
should possess a somewhat rounded tip. Some two or three inches
behind the tip, lateral branches, rootlets, will be seen, light in
colour and much smaller than the main root. About half an inch
behind the apex of the root, there is a slight expansion of the
root, covered by particles of soil which are rather difficult to rub
off. This bulging portion extends for perhaps half-an-inch along
the root. On washing it carefully in water, it will be found to be
covered with delicate white hairs — the root-hairs — through which
the absorption of water takes place. Notice how firmly the par-
ticles of soil stick to them, so that the hair is often torn on trying
to rub the soil away. This is due to the fact that the surface of
the hair often becomes transformed into a kind of jelly, in which
particles of soil get embedded. These particles become decom-
posed and the mineral substances contained in them dissolved,
partly owing to the secretion of an acid by the root-hairs, and the
solution thus obtained is then absorbed.

Between the hairs and the root-tip, a clear space exists, deli-

ON THE STRUCTURE OF THE ROOT. 69

cate looking and of a bright yellow colour. This is the growing
point of the root, and it is here that the cells are in their simplest
condition, and all new tissue has its origin. This root apex has to
force its way between the particles of soil, and lest the delicate
tissues of which it is composed should be injured, it is protected
by a rough-looking, brown covering, called the root-cap, which is
formed at the extreme apex. As the root-cap is worn away in its
progress through the soil, it is renewed from the young growing-
point. Behind the root-hairs the root is yellowish brown and
somewhat rough-looking.

These are the only observations that can be made without the
dissection of the root and the use of the microscope.

If we take transverse and longitudinal sections from various
parts of the root, we can observe and locate the internal structures.
For section-cutting, roots should be preserved and hardened in
methylated spirit. They should be placed in 70 per cent, alcohol
for at least twenty-four hours before cutting, or they may be pre-
served indefinitely in this solution. If pure methylated spirit
cannot be obtained, absolute alcohol, although expensive, must be
used. To test the purity of the methylated spirit add a little
water to a small quantity. The spirit is unsuitable if the mixture
turns milky. There are other methods of preserving and harden-
ing, but methylated spirit is necessary with all of them, and the
above is perhaps the best suited to a beginner.

In order to cut and mount sections, the following apparatus is
necessary : — A sharp razor, three or four watch-glasses, two or
three camel-hair brushes, a dish containing methylated spirit or
absolute alcohol, a small bottle of a rather thin solution of Canada
balsam in xylol, xylol or oil of cloves, a stock of 3 x i glass slips,
thin cover-glasses, and a staining solution, such as Bismarck
brown. The process of preparation may be divided into five
operations : —

I. — Sectionising. — Take a piece of root, including the tip,
about an inch in length. Hold this in a perfectly upright position
between the forefinger and thumb of the left hand, the cut end
slightly projecting above. Rest a sharp razor, well wetted with
spirit, in a horizontal position on the tip of the forefinger, and
draw it over the root so as to cut thin transverse slices. It is

70 ON THE STRUCTURE OF THE ROOT.

important that the razor should be kept quite level and the piece
of root in an upright position, otherwise there would be a danger
of the sections being cut obliquely.

If any difficulty be found in holding the root firmly, it should
be embedded in pith in the following manner : — Take a piece of
elder pith, about one-third of an inch in diameter and as long as
the material to be cut. Slice away the outer hard portions, and
divide the remaining soft cylinder longitudinally in half. On the
inner flat face of each half make a groove sufticiently deep and
parallel to the sides, and fit the piece of root into these grooves ;
fasten the halves together with a ribbon pin and place the whole
into 70 per cent, alcohol for a minute. The root is now supported
on all sides by the pith, and sections are cut through pith and all.
These are transferred to a watch-glass of 70 per cent, alcohol, and
the pith sections picked out with a camel-hair brush. Draw off
the alcohol by means of a pipette with an aperture too small to
allow the sections to pass in, and add 30 per cent, alcohol. After
the sections have come to rest, remove the weak alcohol and add
water.

2. — Staining. Replace the water with a solution of iodine
green and allow to stand for an hour, when the sections will be
found to be much overstained. Draw off the iodine green and
rapidly wash in 50 per cent, alcohol, which should be then drawn
off quickly. Now treat the sections with a solution of Bismarck
brown for ten minutes, and wash rapidly in 70 per cent, alcohol.

3. — Dehydration. The sections are now placed in methylated
alcohol and then into absolute alcohol, to free them from all trace
of water.

4. — Clearing. Replace the alcohol with a mixture of equal
parts of absolute alcohol and oil of cloves. When the sections
have come to rest, remove the mixture and add oil of cloves.

5. — Mounting. — The sections may now be picked out with a
dry camel-hair brush and mounted in balsam. The section should
be placed on the middle of the slide, a single drop of balsam
placed on it, and covered by a thin, clean cover-glass. The pre-
paration may be examined at once, but will not be dry for some
days.

By this method the xylem, endodermis (and suberised tissue

56

44

78

22

o'5 gram.

...

150 C.C.

* ■ '

I gram.

100 c.c.

ON THE STRUCTURE OF THE ROOT. 71

in the older root) are stained green and the phloem and cell-walls
brown. The iodine green may be left out, in which case the sec-
tions should remain in the Bismarck brown solution for an hour,
and then washed well in 70 per cent, alcohol. The phloem and
endodermis will be found to stain more deeply than the surround-
ing tissues.

Preparation of Soluimis.
Alcohol : —

30% Methylated spirit (unmineralised), 33 vols, water- 66 vols.

5°% M 11 ))

7% >> >) ij

Iodine Green Solution : —
Iodine green
Water

Bismarck Brown Solution : —
Bismarck brown
70% alcohol

A section taken just behind the root-hairs — -say, one inch or a
little more from the tip of the root — should be first examined, as
it shows the typical structure.

With the naked eye or a pocket-lens, two distinct parts can be
made out in the section : a central dark portion, which we call the
central cylinder, and an outer lighter portion, the cortical cylinder
(Fig. i). Examined under a magnification of 50 to 100 diameters,
we see that both the central and the cortical cylinders are made
up of cylindrical or polygonal cells, varying in size and appearance,
but all consisting of an outer wall or membrane and an internal
cavity. Even with such a low power it is seen that the cells are
differentiated into groups or bundles in the central cylinder, which
is clearly marked off from the cortex by a ring of black cells,
known as the endodermis (Fig. 2).

Let us now examine under a higher power (a i/6th or i/4th
objective) a section double-stained with Bismarck brown and
iodine green.

On the outside will be seen a more or less regular layer of cells,
somewhat dark and rather smaller than the cells just inside it.
This is the outer layer of the cortex (Fig. 2,//.), and its function
is to protect the delicate tissues inside it. For this purpose the

72 ON THE STRUCTURE OF THE ROOT.

cell-walls have become to some extent cuticularised by the impreg-
nation of part of 'the cell-wall with cutin, a substance something
like cork and impervious to water. In the stem there is a distinct
layer outside the cortex, set apart to perform this function ; but in
the root the layer which corresponds to the epidermis in the stem
is used for another purpose, and the function of protection is
taken on by the outer layer of cortical cells. If we look carefully
enough, we shall see outside these cells a thin layer of a somewhat
ragged brown substance (Fig. 2,pl.), which is all that remains of
the outermost layer of the root corresponding to the epidermis of
the stem. This outermost layer gives rise to the root-hairs, and is
therefore called the piliferous layer, and its function is to absorb
water and salts in solution.

Immediately inside the protective layer are several layers of
cells somewhat circular in outline, and so arranged as to leave
larger or smaller spaces between the cells (Fig. 2, c). These cells
extend up to the limits of the central cylinder, and are called the
cortical cells. They contain large quantities of water, and the
interspaces may be regarded as air-spaces, through which air can
reach the various tissues. The cortex sometimes acts as a store-
house for food, and in some roots is the seat of the formation of
secondary structures, such as cork. The water contained in the
cortex can be taken up when required by the plant, and through
the cortical cells water is conducted from the root-hairs to the
central cylinder.

The innermost layer of the cortex is called the endodermis
(Fig. 2, e) — that is, inner skin — in contradistinction to the outer
skin or epidermis. This layer has a peculiar structure. The cells
are similar in shape and size and are closely fitted together like
bricks, so that there are no air-spaces at all between them, and the
communication between the air-spaces of the cortex and the
central cylinder is completely cut off. Furthermore, these cells are
cuticularised, but in the majority of cases the radial walls only are
changed in this way, and not the tangential, inner and outer walls.
Water can thus pass through the cells in a radial direction from
the cortex to the central cylinder, but not sideways from one cell
of the endodermis to another. In the lime, however, the endo-
dermal cells appear to be cuticularised all round except in that

ON THE STRUCTURE OF THE ROOT. 73

part of the root where the root-hairs are given off. We thus see
that in the region of the root-hairs water can easily pass through
the endodermis from the outside, but that in the higher regions of
the root the complete cuticularisation of the endodermal cells
prevents the passage of water inwards or outwards, so that the
water taken into the central cylinder cannot escape.

Inside the endodermis we see that the cells of the central
cylinder are grouped into masses or strands, and we shall find that
each of these groups of cells has a certain function to perform.
(A group of cells which performs any special function is called a
tissue.) First, we shall notice six distinct bundles of cells, which
possess very thick walls, and can be recognised quite easily, as they
stain a greenish colour in the iodine green and Bismarck brown.
These are termed the Xylem or wood, and in longitudinal section
will be seen to consist of long fibres or tubes, marked by spiral or
other thickenings or pits on the walls. It has been shown conclu-
sively, by a series of elaborate experiments, that the function of
these tubes is to conduct water from the roots to the other parts of
th6 plant, and we can trace them to all parts of the plant, even to
the tips of the leaves and to the smaller branches. These groups
of tubes are called vascular bundles — i.e., bundles of vessels.

Alternating with these bundles, and somewhat more circular or
perhaps tangentially oval in outline, are other bundles of small,
thin-walled cells (Fig. 2, ph.). These are not so clearly differen-
tiated from the surrounding tissues as the xylem bundles. They
have, however, a very definite structure and function. The struc-
ture can only be made out and the tissue clearly marked off from
the surrounding cells by longitudinal sections, in which it will be
seen that these bundles are made up principally of long tubes,
interrupted at intervals by a transverse wall, which is perforated
like a sieve. It is not easy for beginners to make out this struc-
ture in a root, as it requires extremely careful section-cutting, but
such sieve-tubes or sieve-vessels can be easily obtained by cutting
longitudinal sections of the stem of a cucurbitaceous plant. It
has been shown that this tissue, to which the name of phloem is
given, is concerned in the passage of food material down the plant
from the leaves through the stem to the roots. We have thus in
the central cylinder two distinct sets of conducting tubes : one for

74 ON THE STRUCTURE OF THE ROOT,

the upward conduction of water and salts in solution, and one for
the passage of prepared food material downwards.

Between the endodermis and the vascular bundles are one or
two layers of cells, known as the pericycle (Fig. 2, pc). This
layer is very important, inasmuch as it is the seat of origin of the
lateral roots, which all begin to grow in this tissue, and force their
way through the cells of the cortex by a process of digestion.
The pericycle may also be the seat of changes which result in the
formation of a new cortex, at the time when the old one is thrown
off, owing to an increase in the size of the root.

The tissue around the vascular bundles is called parenchyma,
or fundamental tissue, and is of the same nature as the cells of the
cortex, both having undergone little change since their formation
at the apex of the root. The centre of the root is occupied by
the pith (Fig. 2, /.), which is also composed of parenchyma, but
with somewhat thicker walls.

If we now examine sections cut in different regions of the root,
we shall see that, according as the section is taken nearer or
further from the apex, the structure will be less or more complex.
In a section quite near the apex, all the cells have practically the
same structure ; we find there no differentiation into Xylem,
Phloem, Endodermis, etc. Each cell consists of a cell-wall, pro-
toplasm, and nucleus. The protoplasm fills up the entire cell and
contains no vacuoles (Fig. 5). A little further removed from the
apex, we find that the cells have a slightly different structure.
Vacuoles appear in the protoplasm, causing it to become restricted
to the wall of the cell and to a few strands running out from that
which surrounds the nucleus (Fig. 6). At the same time the cells
are seen to differ in size, and groups of small cells, arranged regu-
larly, represent the future vascular bundles. The further away
from the apex, the more does the protoplasm become restricted to
the wall of the cell ; and in some cases it disappears entirely.

We can, in fact, show by a series of sections, longitudinal and
transverse, that the formation of new cells takes place at the apex
of the root, and that the various tissues of the root are produced
by a gradual modification of these. To form the xylem the cells
are gradually elongated, the transverse walls between groups of
cells placed in rows end to end disappear, and long tubes or

Journal of Microscopy 3^ Ser Vol 6.P1 ^^

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■^' ^'^^^'^^r W^Q<fe

pt, .

% ■|^Ji_4__r— 4--4.^>4,,-l ^ ,..4 I _._^?

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F Phillies Sc.

Root Structure.

ON THE STRUCTURE OF THE ROOT. 75

vessels are formed, strengthened by spiral, reticular, and irregular
thickening of the wall ; while at the same time the protoplasm
disappears, so that these cells may now be said to be dead.

Modifications of a similar nature take place in the production
of phloem, but here the transverse walls are only partially broken
down and converted into sieves, through which insoluble proteid
matter, which is not capable of passing through organic mem-
branes, is able to make its way. It must not be supposed that the
sieve-plate functions as a sieve in the sense of sifting one thing
from another. The reason for the existence of sieve-plates in
what would be otherwise an open tube may be partly due to the
necessity for some strengthening partition to prevent the collapse
of such long, thin-walled tubes, and partly to enable the tubes to
be completely closed at certain times — notably in winter, when
very little active formation of food materials is taking place.

The parenchymatous cells of the cortex and the central cylin-
der are only slightly altered in structure from those described in
Fig. 6. They possess a thin layer of protoplasm on their walls, a
large central vacuole containing cell-sap, and a nucleus generally
found in the layer of protoplasm on the cell-wall (Fig. 4).

Such is the general structure of the root, and the roots of all
flowering plants will be found to possess this structure in principle
at an early stage in their development. At a later stage, in the
root of the Lime and others of a Uke nature, secondary formations
appear, resulting in the production of a much larger quantity of
xylem, until the greater part of the root becomes woody. This is
the condition of all the older roots of our perennial dicotyledons.

EXPLANATION OF PLATE IV.

Fig. 1. — Transverse section of root, about 1 in. behind the apex, x 4 :

c, Cortex; c.c. Central cylinder.

,, 2. — The same section, magnified about 150 diameters : —

2).l., Remains of the piliferous layer; pt., Outermost cortical
layer, protective layer; c. Cortex; e., Endodermis ; p.c. ,
pericycle ; /., Fundamental tissue^parenchyma ; 2^h., Phloem
or bast ; x., Xylem or wood ; j}., Pith.

,, 3. — Section showing piliferous layer (somewhat diagrammatic) : —
l^.l., Piliferous layer; r.h., Root-hairs; pt, Outermost layer
of cortex.

76 SELECTED NOTES FROM

Fig. 4. — A single cell of the cortex, magnified about 250 diameters : —
C.W., Cell- wall ; pr., Protoplasm ; v., Vacuole containing
cell-sap ; n.. Nucleus with nucleolus.

,, 5. — A young cell from near the apex of the root, x 250 : —
pr., Protoplasm ; v., Vacuole ; n., Nucleus.

,, 6, — A young cell, further removed from the apex than Fig. 5.
Same magnification ; lettering the same.

Selectet) IRotca from tbe (Postal flDicro6co«*
pical Societ^'0 W[otc^1Boo\{Q.

Ant-Lion (Larva of). — This insect is a very interesting one, and
one about which considerable misapprehension exists ; at least, I
was quite surprised when it was pointed out to me among the sand
at the mouth of a large cave called the " Four de Berne," which
is situated in the Cliffs that overhang the brawling stream which
issues from the Val de Travers (Canton Neuchatel), Switzerland.
On enquiring for the way to enter this gorge, to my surprise I
found that the peasant to whom I spoke had suspected my nation-
ality and spoke to me in good English, which he had acquired
during a residence of several years in America.

He knew something of Geology, and took a most intelligent
interest in other matters connected with Natural History, and not
only showed me my way, but accompanied me for some distance,
and took me to the entrance to this cave, where we parted.

He informed me that he had been employed by a Swiss gentle-
man some years ago to search for prehistoric remains, in which
they had been very successful, and while we were sitting on a stone
conversing together, he drew my attention to some long, narrow
tracks which had been made in the dry sand, and asked if I knew
what they were. I did not know, as I had never noticed such
markings before. He pointed out that these winding tracks inva-
riably ended in a little depression in the sand, circular in shape,
with sloping sides, and about an inch deep. Putting his finger
into the sand at the side of this hollow, he shoved it underneath,
and from the bottom he haul'd out a dirty-looking little " critter,"
about the size or rather bigger than the one which is so thoroughly

THE society's NOTE-BOOKS. 77

squashed on Mr. Tait's slide. It seemed decidedly averse to being
introduced to the daylight, and was woefully stubborn, for no
amount of gentle titillation applied to the region where his tail
would have been if he had one would induce him to move for-
ward, but when the straw was applied to his head he wriggled
himself backwards.

His appearance and demeanour suggested thoughts of the
"amoosin' little cuss " of Artemus Ward. My guide (Emile was
his name) informed me that they always travel backwards, and
that when their little pit gets destroyed by being filled up with
loose sand that they reconstruct it again by jerking out the sand
by bending their abdominal segment under them, and then relax-
ing it again with some force. In this way they form their little
pits in about a couple of hours, and then bury themselves in the
sand below, only leaving the points of their mandibles exposed.

Any ant or small insect which unwarily passes over the brink
of the little pit slides into it as the loose sand gives way beneath
it, and it has nothing to which it can cling. " Facilis descetisus
dvernt." It is easy to get in, but hard to get out. The horrid
mandibles grip him, a struggle ensues ; but it is soon over, and the
plump body of the ant is soon reduced to the condition of a
sucked orange. These little pits were very numerous at this
place, but though I looked for them on several occasions else-
where on my travels, I never saw any indications of their presence.
They can only construct their pits where there is dry, loose sand
or any light soil ; a shower destroys the pits at once, and they can
only be reconstructed when the sand becomes dry again.

J. C. Christie,

Aulacomnium Androgynum — This moss is found growing
rather plentifully on decaying stumps in damp woods. It is one of
the AcROCARPUS (terminal fruiting) section, but is very rarely
found in fruit. To compensate for this, the male plant in spring
sends up a short stalk bearing a number of gemmae (which are
analogous to the bulbels of some ferns and flowering plants, as
Asplenium bulbiliferu?n, Sileum iigrinutn, etc.). These gemmse,
when mature, fall to the ground, and grow up under favourable
conditions into plants like the parent one. There is something
very remarkable in the fact that this single cell grows directly into

78 SELECTED NOTES FROM

a perfect plant, with roots, stem, leaves, and fruit. The change is
far greater and more wonderful than in the lower forms of plant-
life, where the cells increase by division, and the perfect plant is
only unicellular.

The specific name, Afidrogymitn, was given in error, it being
formerly supposed that the gemmae were the male flowers.

W. N. Cheesman.

Aulacomnium Androgynum.— This moss is described as having
leaves "irregularly toothed at the apex" (Berkeley); "all denticu-
late at the apex " (Hobkirk), which I do not observe in Mr.
Cheesman's specimen, except on two leaves, and that only
obversely, even with |-inch o.g. Is the " toothing " of the leaves
always so very slight ? Instead of each gemma being " a single
cell," they appear to me to be as described by Berkeley in the
Handbook of Brit. Mosses, p. 206 :— " Broadly fusiform, apiculate,
and 3 — 4 septate." W. H. Lett.

Asterina. — Is a genus of Micro-fungi. One species, A. Babhig-
tonii, grows on living box leaves : — " Perithecia semiorbicular,
seated on a byssoid— /.^., silky — mycelium, mouthless, at length
splitting irregularly. Asci short, mostly sub-globose."

C. H. Waddell.

Celsia, Stamens of. — The genus Celsia belongs to the Solanacce,
and comes very near to the Verhascum (Mulleins), of which we
have some wild examples in this country, all of which have hairy
stamens. Several of the genus are natives of the Mediterranean
district of S. Europe and N. Africa. The vase-like hairs at the
base of the flower will not be overlooked. When the flower is
quite fresh, the numerous trumpet-like hairs are very beautiful.

J. ROOKLEDGE.

Ammonites plavicostatus.— This is, if I remember rightly, a
Lias species. The Ammonites, a genus of chambered shells, found
only in the secondary rocks, but exceedingly abundant in some of
them, are allied to the existing Nauiihis, but differ from it by
having the sutures between the several segments of the shell foli-
ated like those of the human skull, whereas in the Nautilus they
are straight. In the Nautilus, too, there is a single siphuncle or
tube connecting the chambers which pierces the septa near the

THE society's NOTE-BOOKS. 79

centre, whereas in Ammonites there are several siphuncles at the
margin of the septa. The shell of the Ammonites, when favour-
ably preserved, shines like that of the Nautilus, with beautiful
iridescent hues ; it is of a nacreous structure, resembling that of
the Gasteropods, or the inner layer of the shell of the Lamelli.
branch bivalves. H. F. Parsons.

Alpine Rose, Leaf of the, from Montauvert— The writer would
feel obliged if some member would inform him the name of the
Micro Fungi upon the same, and how to remove the beautiful
star-shaped Raphides from the leaf, and the best method of
mounting the same as transparent objects. The plant is believed
to be a wild Rhododendron, and is very common in the Swiss
mountains. Travellers are very fond of decking themselves with
bunches of the crimson flowers to show that they have been for a
climb. A. Kempson.

Ditto. — I have travelled through many miles of these, but had
no idea that their apparently smooth leathery leaves were so beau-
tifully covered with crystals. Though found at Montauvert, it is
much more abundant a few miles further on the range; in making
the ascent of Mont Blanc from Chamouni, the upper lower ranges
are covered with it, reaching to Pierra Pontua, just below the
Snow-line. J. Rookledge.

Ditto. — The two species of dwarf Rhododendron called "Alpine
Rose " are R. hirsutum and R. feirigineum ; the latter is the one
under observation. The beautiful discs on the u?ider side of the
leaves occur in both species, and are similar yet different. I for-
merly wrote some notes in our books on the subject, and enclosed
specimens showing how these rosulate hairs, not crystals, extended
over calyx and corolla, and therefore I now limit my remarks to
saying that, by means of these hairs, I can often trace the parent-
age of garden hybrids known by mere florist's names, such as
R. Wilsoni, R. Getsoni, etc. While writing, I find the species
and varieties mentioned are now in full bloom in my garden. The
hairs \n freshly gathered blooms are lovely in the extreme — pressed
and dried the vivid colours of the leaves and petals fade, and the
appearance is as changed as that of a mummy from the living
person.

80 SELECTED NOTES FROM

Plant hairs should be studied on the living plants, and at
various stages of growth ; they are usually most dense on the
unopened bud, their chief office being apparently to clothe and
protect it, a happy illustration of utility and adornment combined.

It is desirable to cut sections of the leaves to show the attach-
ment and embedding of the hairs. This is easy enough for the
purposes of observation, although it is not so easy to mount per-
manent specimens, as a fluid mount is required. W. Teasdale.

Ditto. — Some years since I made a careful examination of the
hairs of a good many plants, and would strongly indicate the study
of leaf appendages to the attention of any " low power " micro-
scopist who is hard up for a subject to work at. Amongst
Rhododendrons, the leaves of R. Nuttalli are, perhaps, the
prettiest and most interesting. H. Pocklington.

Acrostichum alcicorne is now known as Platyceriiim alcicorne.
It is a native of the tropics, and is found in the East Indies,
Malayan Archipelago, and Australia. The name AcrosticJmm was
originally given to it and others whose fructification was borne on
the end or tip of the fronds— aKpoc [acros), highest; onxog [stichos),
order. The name Platycerium is given because the fronds are
divided in broad segments like stags' horns, from the Greek nXaTvg
{platys) and ^tpaq (cepas), a horn. W. H. Lett.

Aregma bulbosum (Bramble Brand). — This is the leaf fungus
which produces the black dusty spot on the back of the Bramble
leaves in autumn. It generally occurs in company with the Fuc-
cinia peculiar to the Bramble, which appears as bright yellow or
orange spots ; indeed, there seems every reason to believe that
they are different forms of fruit of the same fungus. Both were
very plentiful in this neighbourhood (Glasgow) this autumn (1882).
I noticed a minute larva feeding on the spores of the Puccinia,
which were quite visible in its interior. W. Goodwin.

This Aregnia is more common than is generally supposed. I
found some fine specimens a day or two ago (Jan., 1883) growing
upon a moss gathered near some bramble bushes. E. Hunter.

Aregma obtusatum spores.— Mr. F. Carey investigated the
structure of these spores, and one of his conclusions, quoted from
the Quarterly Journal of Microscopical Science, is as follows : —

THE society's NOTE-BOOKS. 81

" The idea of the fruit consisting of Sporidia united together and
forming a chain is certainly not in accordance with the true struc-
ture. The Sporidia are not united to one another in any way, but,
although closely packed for want of space, they are, in fact, free
in the interior of what may be called a sporangium or ascus."
After explaining the manipulation employed to prepare the spores
and fruits by which he arrived at this conclusion, he goes on to
say : — " By this means the fruit" — i.e., the whole spore as seen on
slide — " was found to consist of an outer membrane nearly trans-
parent (and studded with tubercles)"— this refers to any other
species of Aregma — " and that this membrane enclosed a number
of cells which constituted the apparent joints, and which were
naturally flattened at either end by mutual pressure. When the
outer membrane was dissolved or ruptured, these cells escaped
and became detached from each other. The cells, thus set free,
exhibited a brownish-yellow ring around a paler area, in the inte-
rior of which an inner cell was visible, sometimes globular, often
irregular in shape. The examination of the ring was not entirely
satisfactory ; it appeared to be sometimes marked with concentric
lines having the appearance of wrinkles. The inner cell had
granular contents and a central nucleus. When perfectly free,
they were spherical in form, with a distinct membrane of their
own, but colourless, except when acted upon by reagents. The
means employed to determine the existence of these cells was to
soak the spores in muriatic acid ; then upon pressure of the glass
cover the outer membrane, and ringed cells were ruptured and the
inner cell escaped." Although these remarks will be well known
to those who have studied this branch of Microscopy, I have ven-
tured to quote them in order to make the slide interesting to those
who have not studied it. J. W. Steward.

Aregma obtusatum, Strawberry brand.— The specimen is,
perhaps, one of a common species, but it embraces two kinds of
spores, the relation between which is a matter of dispute with
some of our best mycologists. The leaf is that of the wild straw-
berry, and the fungus upon it is one of the Aregma or genus
having four to seven celled spores.

The present species is called by some Phragmidium obtusatum,

but by Dr. W. C. Cooke, in his Microscopic Fungi., it is called

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. g

82 SELECTED NOTES FROM

Aregma obtusatum. It is accompanied on the leaf by the orange
spores of a species of Lecythea, Cooke says, in the work above
referred to : — " The association of one-celled, orange-coloured
spores with the brown two or more celled spores passed in review
is another feature worthy of a passing notice, and which opens a
field for discussion. It is generally admitted that these two forms
are the production of the self-same mycelium or vegetative system,
but it is not so generally admitted that they are but two forms or
phases of the fruit of the same plant. It is not at all uncommon
in the history of mycology to find two forms which were for a
long time considered to be distinct plants producing different
forms of fruit, and which bore different names, and were located
in different genera, at length proved to be only the self-same plant
in different conditions, and ending in one name being expunged
from the list. Such a fate probably awaits, at no distant date, the
orange spores which precede or accompany the species in the
present genera (p. 74). T. Whitefoot, Jun.

Desmids.— One of the peculiarities of desmids is their exceeding
symmetry, each half of the cell (for though apparently double, it is
really single, as is shown if a puncture is made, the whole cell-
contents being emptied) being identical, the same number of
starch-grains, if they exist, being shared equally in the same rela-
tive places (the same with chlorophyll, etc.) ; this bilateral arrange-
ment is, if I may use the term, very animal-like.

These organisms are best examined in their fresh state. On
the slide the cell-walls show most distinctly ; the interior contents,
however, are not so clear. This, perhaps, is unavoidable in
mounted specimens. J- Vereker.

Starch-Grains. — To recognise starch-grains, the best way is to
place a drop of dilute aqueous solution of iodine in iodide of
potassium in the water on the slide ; the starch is coloured blue.
Of course, the polariscope may be used instead, but the first
process is very convenient, as it gives a blue colour, and the
polariscope can be used as a confirming test. J. Vereker.

Palates of MoUusca for Polariscope. — These organs, sometimes
called "tongues," are very curious." They are armed with sharp
teeth, and differ as much in the molluscs as the antennae in the

THE society's NOTE-BOOKS. 83

insects. Some authorities object to the popular term "tongue,"
and prefer the long word " odontophore."

It would appear from the testimony of several investigators of
these beautiful objects, that they by no means invariably determine
the species, " although the patterns or types of the lingual mem-
branes are, on the whole, remarkably constant, yet their systematic
value is not uniform, and therefore the attempts to remodel the
Gasteropods by their peculiarities of dentition have not become so
complete a success as teas at first expected ^

Dr. Troschel, who has written a good deal on the subject,
classifies the principal types by means of their lingual dentition,
but the generic characters of each have yet to be ascertained. In
the Patella radiaia the teeth are very strong and numerous, being
also nearly opaque ; those of the Trochus are also very numerous,
but the band is much wider, and " not only are the large teeth of
the lateral bands very beautiful, but the delicate leaf-like teeth of
the central portion have their edges minutely serrated."

The preparation of these palates is by no means easy. You
have to " first catch your hare " — that is, you have to dissect the
object from its surroundings, which are all of a slippery, slimy
nature. Obviously, the dissection must be done under water.
The first touch of the knife or forceps will in most cases have the
happy effect of making the water so turbid that nothing can be
seen. The water must then be changed, and the process will have
to be repeated several times. Hogg gives the following method: —
" The animal having been taken from its shell, pin down the mus-
cular foot to a piece of cork, pour water upon it ; then with a dis-
secting microscope and a good bull's-eye condenser cut open and
expose to view the floor of the mouth ; pin back the cut edges
throughout its entire length, and work out the dental band with
knife and forceps. When the band is detached, place it in a
watch-glass, and again clean it well by repeated washings and a
camel's hair brush ; then place it in weak spirit and waiter, where
it must remain for a few days before mounting. If the membrane
is dense and fatty, it must be soaked for a time in liquor potassae,
and when removed carefully washed. The best fluids for mounting
are weak spirit and water, glycerine, glycerine jelly, or Goadby's
solution. Canada balsam renders them so very pellucid that the
finer teeth are completely lost in it."

84 • SELECTED NOTES FROM

Dodder and its Host. — The Dodders (Cuscula) are parasitic on
such plants as clover, nettle, hops, etc. Most of the species are
annuals dying away in autumn. Before that time, however, the
seeds have burst explosively from the seed vessels, and have been
scattered hither and thither by the wind. All the winter they lie
dormant in the ground, sheltered, in many cases, by decaying
leaves, which supply a suitable soil for germination, which does
not take place until comparatively late in the following year, not
before the nettles and hops have acquired some strength of stem.
From the seed proceeds a little club-shaped root, which seeks the
soil, but the young stem remains surrounded by the seed-hooks
and the store of nutriment which they contain. It grows thin as
a thread, and somewhat spirally at the expense of the seed-stores,
which, however, is soon exhausted ; the thin stem then seeks for
some plant on which to cling. If this be not found, the stem at
length lies prostrate on the ground, and after a strange dormant
existence for a month or so dies ; but if some plant be near at
hand, the dodder plant clings around it after the manner of a
climbing plant. So soon as the stem has embraced that of its
bearer — say, a nettle or hop plant — it throws out attaching papillae,
which penetrate the bark or cuticle, and sends out numerous little
rootlets. These come into close connection with the bast portion
of the hop or nettle stem, and from thence absorb nutrition.
Now, the vessels of the bast form the channels by which the
organic substances manufactured in the leaves pass towards the
root. Such are the spoils which the leafless dodder, unable to
manufacture organic material for itself, absorbs from its host.
After suitable attachment has been effected, the stem continues its
twining growth with increased vigour, and all connection with the
soil is lost, and eventually the parasite bursts into flower. — From
Gedde's Chapters on Modcfn Botany.

Leaf of Durio Zibethinus.— On the underside of the leaves are
found two varieties of stellate hairs, there being first one or two
layers with many rays, and under these a layer with only a few
rays.

Leaf of Deutzia scabra.— These leaves are usually either
mounted dry as an opaque object, or decolourised and stained, or
the cuticle only may be mounted. The specimen now sent is

THE society's NOTE-BOOKS. 85

part of the leaf of the entire thickness, which, after a prolonged
soaking in glycerine, was mounted in glycerine jelly without water.
It should be viewed with polarisco]je without selenite, the prism
being turned to give a dark ground ; it may also be viewed with
selenite.

Sozodont (a tooth powder). — This will be found to consist of
diatoms and starch, the granules of the latter being exceedingly
small.

Aspartic Acid.— When asparagin is dissolved in a saccharine
liquid, which is afterwards made to ferment, or when heated in
water under pressure in a closed vessel, or when boiled with either
an acid or an alkali, it is converted into ammonia and aspartic acid.

Tingis crassicornis— syn. Dictyonota crassicornis— is one of

the Hemiptera Heteroptera. These creatures are " in all stages
of their existence active and suctorial, and the consequent diffi-
culty of supplying them, in confinement, with fresh appropriate
food, few observations upon their natural history have been made
and recorded. There is a gradual development of the creature
after it leaves the egg, not only in size, but in the perfection of its
organs. The larva resembles the imago, and is said to cast its
skin three times before it reaches the pupa state ; the insect is
then still more like the imago ; but some of its organs — such as
the ocelli, wings, and claws — are either rudimentary or are barely
indicated, and only become perfected after the last moult. But
whether each species casts its skin the same number of times, how
long the individuals of each species remain as larva, pupa, or
imago, what species have more than one brood in a year, and what
constitutes the food of each species, are matters that in the great
majority of instances remain to be determined." — Douglass Scott
(1865).

Prepared Cocoa. — This preparation consists of cocoa, with a
large addition of arrowroot and sugar. John Terry.

Prepared Cocoa.- I wish Mr. Terry had told us luhich " pre-
pared cocoa " his specimen represents, for then we would give a
wide berth to that kind, which has so little of the nutritive bean
in it. This slide may give a hint to any of our members who
have them, to circulate some slides of Adulterations.

A. Clarke-Smith.

86 SELECTED NOTES FROM

Stylops Spencii (Parasite of Wild Bee). — The insects of this
order, Strepsiptera, are of small size, the largest being not a quarter
of an inch in length. The body is long and narrow, its greatest
extent being occupied by a very large and singularly developed
thorax. The general character of the body indicates great weak-
ness, and we find accordingly that the insects live but a very short
time in the imago state. The composition of the mouth is very
singular, exhibiting none of that complicated structure we see in
so many insects. This is in effect to be attributed to the fact that
the imago take little, if any, food during its short existence.
These insects are parasitic in their early state in the bodies of
various bees and wasps, the larva, when fully grown, protruding its
head between the abdominal segments of these insects, appearing
at first sight like a small flattened acarus." From lVest70ood's
Classification of Insects, where a long and interesting account of
the order is given. John Terry.

Durio Zebethinus.— The stellate hairs of this plant are very
beautiful objects. The tree is an evergreen and a native of the
East Indies ; it therefore requires a hothouse to grow in, and as it
grows some sixty feet high, it is not likely to be very plentiful in
this country. It belongs to the order Malvacece. J. W. Crick.

Stylops Spencii, — Mr. Terry's remarks would appear to apply
to the male insect only, seeing that the female is utterly degraded,
and passes its entire existence within the body of the host, the
head and part of the thorax only protruding between the abdo-
minal rings, in some cases causing considerable distortion to the
body.

I have never been so fortunate as to take a male specimen of
Stylops, but some two or three years ago during a short stay at
Swanage, in April, I found that in colonies of bees, of the genus
Halictus, fully 25 per cent, of the swarm were stylopsed. The
sac-like abdomen was crowded with multitudes of minute Stylops
larvje, which at that time — possessing six legs and two long hair-
like appendages to the abdomen — presented a very different
appearance to either the mature male or female. E. Bostock.

Dodder.— At Crowboro' I found a quantity of dodder on the
common Heath. A. Clarke-Smith.

THE society's NOTE-BOOKS. 87

Sozodont Tooth Powder comes from Virginia City, Nevada,
California. A specimen in my possession has many more diatoms
in it than this one. It is the silex of the diatoms that gives the
imputed value to this dentifrice. A. Cl.arke-Smuh.

Stylops.— A very good description of this insect, with figures,
may be found in Science Gossip, 1870, p. 4. Shuckard also gives
them a paragraph in British Bees, p. 208. Chas. D. Soar.

Atypus sulzeri.— This spider is glossy, the cephalothorax of
the female is reddish brown. The male is darker ; a smooth oval
space, of a leathery substance, occurs on the front half of the
upper side of the abdomen in the male. This spider is easily
known by the great size of the cephalothorax and falces.

Atypus forms a tunnel in damp earth ; at the end of this
gallery, which runs in a horizonal direction at first, and dips down
afterwards, the spider remains crouching and waiting for its prey.
The female deposits there her cocoon, which is guarded from
the dampness of the earth by being placed on a cushion, formed
of a sticky material and the fibres of plants. Atypus feigns death
when taken. Chas. D. Soar.

Clutiona amarantha.— In this spider the front row of eyes is
the shorter, the middle eyes of the head row are rather wide
apart ; the falces are hairy and have a few small teeth ; the
maxillae are strong, straight, and gibbous, enlarged at the inser-
tions of the palpi. The lip is small at the base, and cut straight
at the tip ; the breast-plate is oval ; the cephalothorax is broadest
behind, and wide at the face ; the shield is yellowish-brown,
reddish in front, and thinly clothed with hairs, a few black hairs
also occurring on the fore part. A dark line reaches about half
of its length, and is succeeded by a series of lines in the form of
obtuse angles, diminishing in length as they approach the tips.
The legs are hairy, spinous, and pale, and there is a hair pad
below the claws. The female is a little more than a quarter of an
inch long. They feed much upon the eggs of other spiders.

The above has been slightly abbreviated from Staveley's
British Spiders. Spiders would prove a most interesting study.
I should like to see it taken up more than has been done by our
members lately. Chas. D. Soar.

[ 88 ]

flDicro0Copical lEccbniquc,

Preparing the Ovaries of Scilla patula.— Miss Lily H. Huie
finds that the best method for preparing the ovaries of S. patiila^
in order to demonstrate the protein crystalloids, is by first fixing
in Mann's Watery Corrosive Fluid. " To a boiling 075 per cent,
common salt solution, sublimate is added to saturation (12 grm.
for 100 CO.). The solution is then allowed to cool, when crystals
of sublimate make their appearance. Preserve the solution with-
out decanting. — M. Heidenhain.

Martin Heidenhain's corrosive sublimate

solution ... ... ... 100 cc.

Picric Acid ... ... "... i grm.

Tannic Acid ... ... ... i grm.

" The tissues were carefully dehydrated and taken through
chloroform into paraffin, and serial sections cut not thicker than
2-3 yu- . . The parafiin sections were spread out on warm water
(40 — 45'^ C), after Gulland, and fixed to the slide by Mann's
albumen method, and then stained in Mann's methylblau-eosine
mixture as follows : —

Requisites. — The staining fluid : —
a. — I per cent, methylblau in distilled water ... 35 cc.
I per cent, water-soluble eosin in distilled

water ... ... ... ... 45 cc.

Distilled water ... ... .. 100 cc,

b. — I per cent, caustic soda solution in ale. absol.

The Methylwasserblau (C37H26N3S3O9 Na 3) was obtained
from Dr. Griibler, Leipzig.

Method.
I. — Stain for twenty-four hours.
2. — Rinse the dark-blue sections in ordinary water.
3. — Dehydrate thoroughly with absolute alcohol.
4. — Transfer the slide to a vessel containing : Absolute alcohol,
30 cc, and i per cent, caustic soda solution in absolute
alcohol, 4 drops. Wait till sections are of a rust colour.
5. — Remove all traces of caustic soda with absolute alcohol.

MICROSCOPICAL TECHNIQUE. 89

6. — Rinse sections in ordinary water for one minute. Red

clouds are given off and the sections become bluish.
7. — Place slides for two minutes into water slightly acidified

with acetic acid. This is done to deepen and fully restore

the blue colour, and also to fix the eosin.
8. — Dehydrate, clear with xylol (not clove oil), and mount in

turpentine balsam."

Preparing and Mounting Head and Proboscis of Blow-Fly.*—

Mr. T. J. Body thus describes his method : — " First catch the
flies ; kill them with chloroform and their tongues will protrude ;
cut the heads off and drop them into a vial of strong carbolic
acid ; let them remain there a few days or until a convenient time ;
take a head out of the vial, and place it on a glass slide or slip ;
puncture the head with a needle, and put over it another slide and
press it flat ; separate the slips and clean them off (do this several
times) ; place the object on the stage of the dissecting microscope
and examine it carefully ; remove all loose, extraneous matter from
around the head ; if the tongue is crooked or the antennae are
folded over, place them in the position in which they are to
remain ; then press again between two slips and put on a clip, and
let it remain so until the next evening (I do all my work in the
evenings) ; soak again for a day or two in carbolised turpentine ;
wash well in water to remove the acid, using a camel's-hair brush
for this purpose ; then dry between two slips, say, for a day or so ;
then soak in clove oil until ready to mount. Prepare a cell of
gold-size to suit a 5/8 or 3/4 cover glass some two weeks or more
in advance of the time for using it. Remove the object from the
clove oil, and remove all the oil possible with blotting-paper
without touching the object. Put a small drop of benzol balsam
on the centre of the slide, and with a wooden toothpick or needle
spread it so as to cover the space within the cell ; place the head
in the centre of the cell and drop a small drop of benzol balsam
on it ; this will just fill the cell nicely, but it will be a little high in
the centre. Place a clean, warm cover as nearly central as pos-
sible, and let it fall of its own weight ; if the balsam is a little
thick, some gentle pressure may be used, and when the cover is

* The Observer {Practical Microscopy), vi., 1895, PP- 5^— 57'

90 MICROSCOPICAL TECHNIQUE.

down see that it is central, and put on a spring clip ; a little balsam
will ooze out in five or six drops around the cover ; lay it aside to
harden. In about a week's time take off the clip, put the slip on
the turn-table, and if the cover has moved, or is not central, push
on the excentric side, then put on the clip, and in a week's time,
provided care is used in handling, the overflow of balsam can be
removed and the mount cleaned around the cell (I do all this work
on the turn-table), and a seal of shellac varnish put around it.
This cries quickly, and the following evening it can be ringed with
King's Scarlet, Brunswick Black, or some other cement. When
the second coat has dried hard, ring again. A finishing coat may
be put on, but I find it best to wash the mount well in soap and
water, using a tooth-brush as a scrubber, before putting on the last
finishing touches. . . . Before putting the balsam in the cell,
cut four notches, equidistant apart, through the cell, large enough
for a fine needle to pass through, then proceed as above. These
notches are for the purpose of moving or adjusting the object in
the cell ; also to allow for the shrinkage of the mountant. If the
object is not central, a fine needle or wire, or a stiff bristle, can be
pushed through one of the notches and the object moved to suit
the eye.

Neutral Red.*— According to Prof Ehrlich this new pigment is
excellently adapted for biological researches and vital staining, as
it possesses a striking affinity for living tissues. If tadpoles be
placed in solutions of i/io,ooo up to 1/100,000, the animals become
stained in quite a short time, and during the first and second day
of their immersion absorb so much of the pigment that all their
tissues become dark red. The pigment may be seen in the cells
as minute granules. Larger animals may be subcutaneously
injected, and even feeding with the pigment gives good results.
In germinating plants the author obtained successful staining
results, and by combination with other pigments — e.g., methylen
blue, etc. — a double or triple staining.

Ehrlich's Triple Stain. f— Dr. G. Reinbach gives a formula for
the triple stain, as improved by Ehrlich. The author used it for

* Allgem. Med. Centraheit., 1894, vide Joum. R.M.S., 1895, P- 128.
■\ Arch.f. Klin. Chirurg., XLVi., vide Joum. R.M.S., 1895, p. 129.

MICROSCOPICAL TECHNIQUE. 91

Staining cover-glass preparations of blood. Its composition is as
follows : — Saturated aqueous solutions of orange, G., 120 grm.; acid
rubin, 80 grm. ; methyl green, loo grm. ; H^O (water), 300 grm. ;
absolute alcohol, 180 grm. ; glycerin, 50 grm. The aqueous solu-
tions must be saturated. The mixture is not to be shaken, but
the necessary quantity should be pipetted'ofif. The fixed cover-
glass film is treated with the solution for five to ten minutes ; the
superfluous stain is washed off with distilled water, the surface
dried with blotting paper, and the preparation mounted in balsam.

New Staining Process.*— Dr. O. Zacharias recommends the
following process for both animal and vegetable preparations. The
material is laid in 70 per cent, alcohol, and then, for from sixteen
to fifty-four hours, in acetic carmine, prepared by boiling i gr.
powdered carmine for twenty minutes in 150 — 200 gr. dilute acetic
acid, and filtering when it has become cold. The preparation is
washed in dilute acetic acid, and then placed for from two to three
hours in ferric-oxide-ammonium-citrate.

New Fixing Material.t— Under the name "chrome-potash-
sublimate-glacial-acetic-acid," Herr Zenker recommends a fixing
material for vegetable tissues, which has the advantage of pene-
trating the tissue readily, without producing any shrinking. Its
composition is as follows : — 100 parts distilled water, 5 sublimate,
2-5 double potassium chromate, i sodium sulphate, 5 glacial
acetic acid. It may also be used for preparations of the nervous
system.

Cytotropism of Cleavage Cells.J— The following is Professor
Wilhelm Roux's method for demonstrating the phenomena of
cytotropism : — The eggs of Rana fusca, obtained from newly
captured animals at the beginning of the normal period of spawn-
ing, furnished the best material for observation. . . . The
phenomena of cytotropism are seen most readily between cells
separated from the egg in the morula or blastula stage. The
separation is effected by cutting or tearing the egg in an indifferent
* For schungober Biol. Stat. Plon., vide Journ. R.M.S., 1895, p. 127.

\ Munch. Med. Wochenschr., xxvii., vide Journ. R.AI.S., 1895, p. 130.

XAmerican Naturalist, xxix., 1895, PP- 5'' — '2, from Arch. f. Entw'mech.
d. Orgamsmen, II., pp. 44 — 48.

92 MICROSCOPICAL TECHNIQUE.

fluid, such as the white of a hen's egg, or a | per cent, salt solu-
tion. One requires for such experiments a small quantity (5 — 10
ccm.) of freshly prepared white of egg each day. This is prepared
by filtering, in an uncut state, through a wad of cotton. The
preparation must be perfectly clear. The egg, in the morula or
blastula stage, is first stripped of its gelatinous envelope, and
placed on a circular glass plate, about 3 cm. in diameter ; then
covered with about 5 drops of the prepared white of egg, and torn
open with two dissecting needles ; or, after puncturing with one
needle, cut with a small curved pair of scissors. The outflowing
parts of the egg are then cautiously reduced in size by a few move-
ments of the needles. The circular plate is then placed in a
round glass dish (4 — ^5 cm. in diameter), with a rim i cm. high,
containing 10 — 15 drops of water — just enough to fill the space
between the edge of the object-plate and the rim of the dish, but
not enough to come in contact with the white. The purpose of
the dish and the water is to check the evaporation of the medium
in which the egg lies, and thus to guard as far as possible against
concentration of the medium and currents in the same. The dish
offers the advantage that one, on interrupting the observation, can
cover it and so protect the preparation against evaporation. Thus
protected, cells may be kept alive in a suitable medium for one
or two days. The preparation should be immediately examined,
while in the dish, with a low objective (e.g., Zeiss, A). It is impor-
tant that the table of the microscope and the object-plate bearing
the preparation should be perfectly level. The examination of
isolated cells in an uncovered medium has the advantage that one
can easily change the position of the cells with needles or other
means. But it is indispensable for checking results to examine
also preparations covered with a cover-slip. The cover-slip for
this purpose must be large enough, so that at least two of the wax
feet (f mm. high) supporting it may fall on dry points of the
object-plate, where they will firmly adhere and not allow the cover
to slide. A still more complete protection against currents in the
medium may be had by having a moist chamber ground into the
object-plate, and covered with a large cover-slip. The bottom of
the chamber must be flat and horizontal.

After separating the cells of an egg, one searches at first with

MICROSCOPICAL TECHNIQUE. 93

a low power (Zeiss, A) to find two cells separated from each other
by a distance equal to, or less than, the radius of the smaller cell,
and from all other cells by a distance not less than about double
the diameter of the cells. No yolk substance should lie between
or beneath the cells. Such a pair of cells having been found,
higher objectives (Zeiss, C or D) may be turned upon them, and
the cell so adjusted under the ocular micrometer, that the line
connecting their centres will fall length-wise of the micrometer.
In this position, one can easily see whether the cells move towards,
or away from, each other.

Microscopical Analysis of Steel.— At a recent conference held
under the auspices of the French Society for the Encouragement
of National Industry, M. Osmond described a method for the
microscopical analysis of steel. The method proposed comprises,
in addition to the preliminary process of preparing the polished
surface, three operations: (i) Polishing in bas-relief on parchment
with a very small quantity of English rouge mixed with water ;
(2) Etching and polishing on parchment with a mixture of calcium
sulphate, in precipitate, in a suitable vehicle ; and (3) Etching
with tincture of iodine and nitric acid. These three operations
enable one to recognise in the steel five constituents. These
five constituents are associated in combination to form the com-
plex edifice of the structure of steel.

M. Osmond examined four types of steel, possessing a known
proportion of carbon, to discover the manner in which these
combinations varied. As a result of that investigation, M. Osmond
states that the thermic treatment of steel leaves in the structure of
the metal, when cooled, characteristic indications sufficiently
precise to form a useful guide in the manufacture of steel, and also
to enable consumers to determine the quality of the metal supplied
to them. — Scientific American.

Incinerated Leaf of Deutzia — At the annual exhibition of the
Department of Microscopy of the Brooklyn Institute, U.S.A.,
held in January, Mr. G. M. Hopkins, of the Scientific American,
exhibited a beautiful preparation of Deutzia leaf, which seems to
have the merit of novelty. The leaf was reduced to white ashes,
leaving the star-like hairs in situ. Some of the hairs were black-

94 MICROSCOPICAL TECHNIQUE.

ened by the carbon of the leaf; others were white, with pearl-
coloured nodules ranged along the rays of the^ stars, like so many
real pearls.

Mr. Hopkins' method of preparing this object is as follows : —
A small piece of the dried leaf is placed upon a thin, flat copper
plate, and another flat copper plate is laid upon it to^.^keep it
straight. Strong pressure is not required. The plates are now
heated slowly over a flame until they become redjhot ; they are
then allowed to cool, and the upper plate is removed. The piece
of leaf is then found to be carbonised and considerably'shrunken.
Without replacing the upper copper plate, the lower plate with the
carbonised leaf is again brought to a red heat, and, lastly, the
flame is brought into actual contact with the leaf, thus removing
the last trace of carbon, having nothing but the stars and the
white ash.

The object is very tender, but it may be handled with proper
care and may be mounted dry. If it is desired to secure the
stars separate from the ash, one or two incinerated leaves may be
placed in a small metallic box and shaken up until the leaf is dis-
integrated, when the stars may be picked out. — The Microscopical
Bulleti?i.

Tissues Hardened in Formalin.— Dr. Mayer says* : — " The
preparation put on the market is used in a 3 — 5 per cent, solution,
as a fixative and hardening agent. The stronger solutions (10 per
cent, and more) harden better and more rapidly, but for a preserv-
ing fluid the lower concentrations are preferable. The advantage
of formalin is best shown in transparent tissues (cornea, cysts) ;
and wherever colours are to be preserved that would be destroyed
by Miiller's fluid or extracted by alcohol. The results with the
nervous system are very satisfactory, the relations of grey and
white matter remaining very distinct. One noteworthy feature is
that the vapours alone are excellent preservers, so that, if the spe-
cimen should happen to be incompletely immersed, it would
nevertheless keep very satisfactorily if it is kept from drying out.
Such an accident would prove fatal with most other methods.
For histological purposes the fixation is best obtained with more
concentrated solutions.

* Journal of Insanity, July, 1895, p. 131.

MICROSCOPICAL TECHNIQUE. 95

Examination of Sputum for Tubercle Bacillus.— Spengler
[Deutsch. Med. Woch., 1895, No. 15) describes a new method for
the preparation of sputum, wliich it is desired to investigate for
the presence of tubercle bacilH. Equal volumes of sputum and
of warm water rendered feebly alkaline with caustic soda are well
mixed with o"i to i"o per cent, of trypsin and placed in the incu-
bator. Putrefaction is prevented by the addition, two or three
hours later, of a small quantity of crystalline carbolic acid. As
soon as a deposit has formed, the supernatant fluid is poured off,
the deposit was had with pure alkaline water and again placed in
the incubator. This process is repeated several times, and finally
the sediment is collected upon a filter paper and dried somewhat.
Portions are then stained in the usual way. As a rule, in twelve
to twenty-four hours, so little sediment remains that only a few
microscopic slides are needed. If the digestion of the sputum be
not carried on for too long a time, the tubercle bacilli undergo no
modification in their staining properties. — Brit. Med. Journal.

Rapid Staining.— Cullen {Ce/itr. f. allge. Path. 11. Patholog.
Anai., 1895, Bd. VI., No. II., p. 448) describes a rapid method
for staining fresh tissues after hardening with formalin. Sections
can be stained in the post-mortem room within fifteen minutes of
removal of the tissue from the body. The fresh material is frozen,
and sections are cut and placed in 50 per cent, watery solution of
formalin for five minutes, thence into 50 per cent, alcohol (one
minute), and washed in water; they may then be stained and
mounted in the usual way. Another method by which better
results are obtained takes two hours and a quarter. In it the
fresh material is soaked in a 10 per cent, watery solution of for-
malin for two hours, and then frozen, cut, and placed in 50 per
cent, alcohol, The later procedure is as in the previous method.
The pieces of tissue in the second method must not be greater
than two millimetres in thickness. — Brit. Med. Jour uaL

Staining the Wings of Insects.— In No. 4 of Vol. I. of the
Biological Review of Ontario, Dr. H. W. Hill gives the following
method, devised at the request of Dr. Brodie, of staining the
veins in the wings of certain insects : —

Place the whole insect in a strong alcoholic solution of fuch-
sin and allow it to remain there for forty-eight hours. Then

96 MICROSCOPICAL TECHNIQUE.

transfer the insect to water with a pair of fine forceps, and wash it
till no more colour comes away, changing the water if necessary.
While the washed insect floats in clear water, slip a microscope
sUde under it, raise the slide, holding the insect on it with a fine
needle ; separate the wings from the body with a fine scalpel and
remove the body. With a drop or two of clear water on the slide,
float the wings into any desired position, keeping them flat and
unwrinkled, taking care to have no bubbles under them. Remove
any excess of water with blotting paper, and allow the wings to
dry. Then place a drop of thick Canada balsam near them and
heat the slide over a spirit or gas flame. Tilt the slide so that the
now liquefied balsam flows over the wings ; lower a cover-glass
gently into position, and allow the preparation to cool. In exami-
nation the veins will be found red, the depth of the colouring
varying with the length of time of staining, the thickness of the
veins, etc. The colour is well retained, so far as has been tried,
and successful photographs have been made. — Scietitific American.

Improved Borax Carmine Staining Solution. -The ordinary
aqueous solution of borax carmine, widely employed in vegetable
histology, requires almost always the destruction of the cell con-
tents, so that only skeleton-like preparations have been hitherto
produced with this stain. Professor Radais obviates this objec-
tion, however, by the use of an alcoholic tincture, thus prepared :
Powdered carmine, 2 parts ; borax, 8 parts ; alcohol, 70 per cent.,
by volume 200 parts. This mixture is placed in a flask fitted to
an upright condenser and heated on the water, so that the alcohol
boils for twenty minutes. The liquid is then cooled and filtered.
It is essential that the alcohol should be fully 70 per cent, by
volume, so that if an efficient condenser is not available the
strength should be 71 to 72 per cent, at starting. This carmine
solution keeps well in stoppered bottles. Sections should first be
macerated for a few minutes in a little 70 per cent, alcohol before
being introduced into the stain ; in favourable cases ten minutes
at least are necessary to obtain a well-stained result, but the section
may be left in the dye indefinitely without any fear of overstaining.
After withdrawing from the stain, the sections should first be
washed with 70 per cent, alcohol, and then dehydrated with alco-

MICROSCOPICAL TECHNIQUE. 97

hoi of greater strength, and finally mounted in an anhydrous
medium. This alcoholic borax-carmine tincture answers equally
well for double-staining, using iodine green or methylene violet for
the complementary s\.Vi\n.^/our?i. de Pharm. in Pharin. Journ.

Reagent for the Detection of Mucilage in Plant-Cells.—
Guiraud* employs a saturated solution of almost colourless hsema-
toxylin in absolute alcohol, mixed with too times its volume in
hot saturated solution of ammonia alum, as a reagent for the
detection of mucilage in plant cells. The rose-coloured liquid
deposits alum and becomes violet ; it is then filtered and mixed
with 30 per cent, of glycerine by measure. This reagent has the
advantage of staining only the contents of the mucilage cells, and
not their v.'2i\\?,.— Pharmaceutical Journal.

Preparation of Clear Nutritive Agar, —In preparing a nutri-
tive medium for agar-agar, difficulty is often experienced in
obtaining a clear product, filtration being very tedious. A simple
apparatus, devised by Dr. M. Bleish ( Centralb. fur Bakt. und
Parazii., xvii., 403) obviates the necessity of filtration, and yet
enables a clear preparation to be obtained. A cylindrical glass
vessel, of about two litres capacity, has openings at top and
bottom. A perforated rubber cork closes the lower opening, and
through it slides a glass tube, long enough to reach the top of the
cylinder. Fix the latter in a retort-stand clamp and pour in the
prepared agar until it nearly reaches the top of the sliding-tube ;
then place the whole apparatus in an oven at 50*^ — 60" C, until
all the solid particles have been deposited. The apparatus is now
removed, a rubber tube with a clamp is fixed to the lower extre-
mity of the glass tube, and the latter then drawn down a few cen-
timetres below the surface of the agar. On opening the clamp the
clear agar runs through and is collected in a suitable vessel, and
the glass tube is gradually lowered from time to time until the
whole of the clear fluid is removed. It is stated that precipitation
of the solid particles may be facilitated by substituting sodium
phosphate for the carbonate generally used. — Pharm. Jotirnal.

Varnish for Finishing Slides.— In selecting a varnish for finish-
ing slides on which microscopic objects are mounted, it is well to

* Repert de Pharm., 1895, p. 71.

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. h

98 MICROSCOPICAL TECHNIQUK

bear in mind that the cedar-oil, used with immersion objectives, is
a powerful solvent, and may irretrievably damage valuable slides
finished with a varnish, containing ingredients soluble in the oil.
Since it is generally found advisable, for the sake of uniformity, to
use one and the same varnish always, this should be selected with
due regard to the possible use of cedar-oil as an immersion fluid.
One of the simplest varnishes to make and use — sealing-wax
varnish — is also unaffected by cedar-oil. It should be made by
dissolving the finest sealing wax (preferably black) in methylated
spirit, and of such a consistency as to flow easily from the brush.
Before applying the varnish, the glass cover should be firmly
cemented with caoutchouc cement (Beale's formula, dissolve
separately equal parts of bottle india-rubber and shellac in mineral
naphtha to desired consistence), or the Gram-Riitzou composition
(Canada balsam, 5 gm ; shellac, 5 gm. ; absolute alcohol, 5 gm. ;
ether, 10 gm.). When the cement is quite dry, and not before,
apply a thin coat of the varnish. A somewhat important point is
the kind of brush to use. Best of all are sable " writing pencils,"
" crow," and " small duck " being suitable-sized quills. These do
not come to a point when in use, and form perfect rings with less
trouble than those that do. They should be carefully washed
after use in alcohol, mineral naphtha, or turpentine, according to
the nature of the cement or varnish employed. — Pharm. Journal.

Micro-Photographic Drawings.— Unna, the eminent dermato-
logist of Hamburg, suggested in 1892 a method of making repro-
ductions of micro-organisms, which is much superior to the
ordinary methods of either drawing or photography, combining the
accuracy of the latter with the clearness and comprehensiveness of
the former. The method is as follows : —

From properly stained specimens negatives are made. From
these negatives light prints are made on soft paper, upon which it
is possible either to draw or paint without further preparation.
The photographs thus obtained give only the outlines of the
object or a skeleton of the picture which it is intended to produce.
By the aid of the micrometer screw of the microscope, the
appearance presented in the various strata of the specimen may
be easily sketched in by an artist. A more complete picture may

NOTES. 99

be reproduced by the half-tone process, and thus better results
obtained than are possible by either drawing or photography
alone — Modern Medici7ie.

motee.

DR. Cole, in his microscopical reminiscences, speaks most
highly of Spencer and Son's objectives. He says : — " I
know that with a Spencer one-tenth homogeneous immer-
sion, N.A. I "38, belonging to my frieid, Mr. Henry Benett, I have
resolved the dots in Amphipleiira pelliicida as clearly and distinctly
as those shown by Dr. Henry Van Heurck in The Microscope as
the result of photographing the frustule with Zeiss's two-millimetre
objective, N.A. r63. The result was achieved under the follow-
ing conditions, which, by measurement, increased the N.A. of the
objective from 1-38 to i'52. The objective was made with wide
collar correction for use with a lo-inch tube, the English and
American standard. By Dr. Henry G. Piffard's suggestion, the
tube was shortened to the Continental standard — six inches — the
systems closed, monobromide of naphthaline used as immersion
fluid for both objective and condenser, and a slide of Amphipleura
pellucida, which I had mounted especially in media of nearly 2*5
refractive index, placed in position on the stage. The result was
simply wonderful. The beads stood out as distinctly as those of
Pleurosigma angiilatum under a good immersion objective. The
same slide, under similar conditions, was afterwards shown by
Dr. Piffard to Spencer himself and Dr. Curtis, President of the
American Microscopical Society. Both were delighted, and said
they had never before seen such perfect resolution of the diatom.
I think Spencer's lenses, for all practical purposes, equal to Zeiss's,
while, having no fluorspar in their composition, they are not subject
to disease. No special slides, cover-glass, condenser, or eyepieces
are required."

At the March meeting of the Royal Microscopical Society,
Mr. Conrad Beck told a funny story about a gentleman who had
invented a microscope which was said to possess the remarkable
power of showing chemical molecules. Mr. Beck went to see the
instrument, "and found that the microscope had not at present
done this, but it was about to do so. It was a home-made instru-
ment, and had been devised by a gentleman who had made the

100 NOTES.

discovery that by drawing out the draw-tube an increase of magni-
fying power could be obtained, and who was of opinion that with
an unlimited length of tube an unlimited power could be got ;
and that by using an electric light and a ^-inch objective, he
would, by going to the top of the house and looking down through
an eyepiece, be able to obtain enormous magnifying power ! " —
Journ. R.M.S., 1895, p. 256.

In a recent number of The Diatomiste (11., pp. 39, 40), Prof.
J. Brun claims to have settled the question that the pearls of
diatoms are cavities, and not protuberances, in the following way :
If a particle of a transparent body immersed in a liquid is first
exactly focussed under the microscope and the tube then raised,
the object will appear to have a bright centre if its index of refrac-
tion is higher than that of the liquid ; a dark centre if the index
is lower. If the tube is lowered, the results are the opposite.

If a diatom with large areas — such as a Coscinodisais — is
immersed in styrax or monobromide of naphthalin, and examined
in this way, the pentagonal siliceous network is shown to have a
lower index of refraction than the styrax, while the interior of the
pentagon has not, showing that it must be a cavity, with the same
index as that of the surrounding medium. If immersed in water,
the inverse phenomenon is observed. -^<?z^r«. R.M.S., iSpSi P- 213.

Mr. G. C. Whipple thus sums up an interesting paper, which he
has contributed to the Technology Quarterly (vii., 1894, pp. 214 —
231), anent the growth of diatoms in surface waters : he considers
" That the growth of diatoms in ponds is directly connected with
the phenomenon of stagnation ; that their development does not
occur when the lower strata of water are quiescent, on account of
greater density, but rather during those periods of the year when
the water is in circulation from top to bottom.

That diatoms flourish best in ponds having muddy bottoms.

That in deep ponds there are two well defined periods of
growth : one in the spring and one in the fall ; that in shallow
ponds there is usually a spring growth, but no regular fall growth,
and that other growths may occur at irregular intervals, as the
wind happens to stir up the water.

That the two most important conditions for the growth of
diatoms are a sufficient supply of nitrates and a free circulation of
air, and that both these conditions are found at those periods of
the year when the water is in circulation.

That while temperature has possibly a slight influence on the
growth of diatoms, it is of so little importance that it does not
affect their seasonal distribution.

That the increase of diatoms takes place substantially in

NOTES. 101

accordance with the law of geometrical progression, and that the
cessation of their growth is caused by the diminution of their
food supply."

At the January meeting of the Geological Society {Quarterly
Jourfi. Geol. Soc, Li., pp. 196 — 209), Mr. E. B. Wethered read an
interesting paper on the formation of oolite. We have already
noted Dr Rothpletz' work on the oolitic granules from the Red
Sea and Great Salt Lake. Mr. Wethered's views are that "minute
fragments of remains of calcareous organisms — such as corals,
polyzoa, foraminifera, crinoids, etc. — collected on the floor of the
sea. These became nuclei, to which the oolitic-forming organisms
attached themselves, gradually building up a crust. Sometimes
this growth was concentric ; sometimes at right angles to the
nucleus of the two combined. When the growth was concentric,
other tubules frequently cropped up in other directions and crossed
the concentric tubules. At the same time calcareous material was
secreted, and the interstitial spaces between the tubules were filled."

In the discussion arising from Mr. W^ethered's paper, Dr. G. J.
Hinde pointed out the striking similarity in the microscopic struc-
ture of the oolitic grains from Great Salt Lake to that of the
Palaeozoic and later oolites, and thought that " if the algal origin
of the former should be confirmed, there could hardly remain any
doubt that the latter was similarly derived." Prof. Judd said that
in 1862 Dr. F. Cohn "pointed out the important part played by
algae in the formation of the Sprudelstein of Carlsbad and other
calcareous rocks " ; that " Bornet, the French algologist, had
insisted no less strongly on the work done in perforation and
breaking up of calcareous fragments by other plants"; Prof Judd
" was inclined to regard some of the structures as due to the
action of destructive rather than to constructive organisms."

A series of interesting experiments has lately been made on
some of the French railways with the use of inclined planes, or
" air-ploughs," for the purpose of lessening the air resistance
experienced by trains. We are told that by means of such an
apparatus a saving of coal, amounting in some cases to 8 or even
12 per cent., has been effected, but something must be deducted
for the excellence of the engine and its driver. We are rather
puzzled as to how M. Ricour makes the slanting planes '■'■four in
three" since, even if they were vertical, they would only be at an
incline of one in one ! Still, as we are informed that the Paris,
Lyons, and Mediterranean Company has had forty engines fitted
with these planes, the invention seems to be something more than
a mere theoretical speculation.

102 NOTES.

Nutritive Value of Sugar. (By N. Zuntz, Omn. Cent?-.,
1895, I., 691 — 692, from Zeit. ver. Riibenzuck., 1894, 64, 71). — By
causing a dog to mount continuously a plane inclined at 10" to
the horizon, and analysing the expired air, it is possible to calcu-
late the amount of oxygen used per kilogram -metre of work done,
and also the quantity of heat produced by the combustion in
which this oxygen took part. The amount of oxygen used per
kilogram-metre of work done was found to be, for a diet of lean
meat, 0-57 c.c. (o'58 Cai.) ; fat, 0*53 c.c. (2 -43 Cal.) ; cane sugar,
0.54 c.c. {2'58 Cal.). Sugar, fat, and lean meat have thus about
the same power of enabling physical exertion to be sustained.
The efficiency of the animal body, considered as a machine, was
found to be about one-third, whereas with steam-engines only one-
twentieth to one-fifth of the energy of the fuel is obtained as
mechanical work.

Can Non-Leguminous Plants Fix Free Nitrogen ? By
F. Nobbe and L. Hiltner {Landw. Ver sticks- Stat., 45, 155 — 159).
— After it was established that LegunimoscE, when suitably infected
with nodule bacteria, have the power of assimilating free nitrogen,
the authors showed that under similar conditions the same holds
good with Elceagnas and with the white and black alder. Podo-
airpus, a conifer, which also has root nodules, seems likewise to
have the power of fixing nitrogen. The same property has recently
been frequently attributed also to non-leguminous plants, which
have no root nodules, the evidence being that the final nitrogen in
the plants and soil was greater than the initial nitrogen in the
seeds and soil.

Heat of the Sun. — In an article in the June (1895) number
of the Astrophysical Journal by H. Ebert, he concludes that the
temperature of the interior region of the sun is in round numbers
40,000*^ C. This is in good agreement with values previously
determined by others.

We shall be pleased to insert Exchange Notices without charge
fojr our readers. — Editor.

[ 103 ]

IRcvlcws.

Modern Microscopy : A Handbook for Beginners. By H.
I. Cross and Martin J. Cole. Second edition. 8vo, pp. 182. (London :
Bailliere, Tindall, and Cox. 1895.) Price 3/6.

This very useful book consists of two parts : — I. — The Microscope, and
Instructions for its Use, by M. I. Cross ; II., Microscopic Objects : How Pre-
pared and Mounted, by Martin J- Cole. The subject matter in both cases has
been thoroughly revised, and much additional information given on the methods
of manipulation. The beginner will find this a most useful book.

A Popular Handbook to the Microscope. By Lewis

Wright. Cr. Svo, pp. 256. (London : Religious Tract Society. 1895.) 2/6.
This is a very useful, cheap, and well illustrated little book. It is divided
into 13 chapters, and-treats of Rays, Images, and Lenses ; Practical Optics of
the Microscope ; the Simple Microscope and its uses ; the Compound Micro-
scope and Accessories ; Microscope Manipulation, Microscopical Drawing,
Measurement, and Photography ; Manipulation, Preparation, Mounting, and
Selection of Objects, etc. etc. There are 1S6 illustrations.

Hidden Beauties of Nature. By Richard Kerr, F.G.S.
Crown 8vo, pp. 256. (London: Religious Tract Society. 1895.) Price 3/6.

The chapters in the book before us contain in simple language the main
points of lectures delivered to Scientific Societies, Colleges, etc., and to large
audiences in various parts of England ; and are well calculated -to help the
reader to take up some department of Nature as a definite study. The chapters
treat of The Study of Nature ; How to Begin ; Sea Urchins ; the Euplectella ;
Atlantic Ooze ; Radiolaria ; Diatoms, etc. etc. There are several plates and
nearly sixty illustrations.

Nature's Story : Science Talk to Young Thinkers. By H.
Farquhar, B.D. Crown 8vo, pp. 191. (Edinburgh and London: Oliphant,
Anderson, and Ferrier. 1895.) Price 2/6.

The author attempts here to bring some of the latest results of science
within the range of young readers, and hopes to interest them in the long and
wonderful life-history of the commonest things ; the titles of some of the
chapters being Flowers, Leaves, Fruit and Seed, The Dispersal of Seed, Pro-
tective Colours, Warning Colours, etc. It is nicely illustrated.

Some Common Insects and other Lowly Forms. By Emily
Dibden. Crown 8vo, pp. 148. (London : James Nisbet «& Co. 1896.) 1/6.

An interesting and instructive book for young people. It treats of Insect
Cities ; Insect Homes — viz. , Wasp Tower, Bee House, Spider Castle, and
Caterpillar Tent ; Our Water-Butt and its Inhabitants ; The Silver Pond and
what we found there; Household Foes — viz., the Spider, the Fly, the Cock-
roach, the Clothes Moth, and the Ant. There are several good illustrations.

A Handbook to the Birds of Great Britain. By R.

Bowdler Sharpe, LL.D. Vol II. Crown 8vo, pp. xviii. — 308. (London :
W. H. Allen and Co. 1896.) Price 6/-

To the list of British Birds two species have been added since the publica-
tion of the first volume a few months ago — viz,, the Sub- Alpine Warbler

104 REVIEWS.

(Sylvia subalpina) and Coues Redpole ( Cannabina exilipes). This volume
of Alleii's Natiiralist's Lilu-a>y contains twenty-seven beautifully coloured
plates, besides a number of illustrations in the text. These books are tho-
roughly readable and full of information. We congratulate the author on their
production.

A Handbook of British Lepidoptera. By Edward Mey-
rick, B.A., F.Z.S., F.E.S., etc. Cr. 8vo, pp. vi.— 843. (London: Macmillan
and Co. 1895.) Price 10/6 net.

This work is designed to enable the student of British Lepidoptera to
identify his specimens with accuracy, and also to acquire such general know-
ledge of their structure and affinities as ought to be possessed by every worker.
The structural characters are, in every instance, drawn from the author's own
observations, illustrations being given of the wing neuration of the different
genera, and, in many cases, species. In the appendix is a classified list of the
better-known Food plants with English names. There is also a voluminous
index.

British and European Butterflies and Moths (Macro-
lepidoptera). By A. W. Keppell, F.L.S., F.R.S., etc., and W. Egmont
Kirby, L.S.A., etc. 4to, pp. xvi. — 273. (London : Ernest Nister.) 25/-

This grand work contains a description of most of the Macrolepidoptera
inhabiting Central Europe, and nearly all of those of the British Isles are des-
cribed or figured. All the British species have English names assigned to
them. In the introduction the Anatomy of Lepidoptera is described with in-
structions for collecting Butterflies and Moths, and Larvae and Pupae, and for
setting for the cabinet. The average expanse of the wings in inches will be
found after the names in the Index of Latin Names. There are 30 very beau-
tifully coloured plates. The book is handsomely bound.

The Elements of Natural Science. Part I., Botany. By
Dr. H. Wettstein. 8vo, pp. xii — 106. (London: O. Newmann. 1894.)

This book presents the subject-matter in such an arrangement that an
expansive treatment of it is possible, and it gives the most needful points of
support for undisturbed progress after oral instruction. It treats of the develop-
ment of the young plant from the seed. The work will be completed in five
parts. There are 155 illustrations.

Die Naturlichen Pflanzenfamilien. By A. Engler. Nos.
123—125. (London: Williams and Norgate. Leipzig: Wilhelm Engel-
mann. 1895.)

These parts contain (he completion of the AsclepiadaceEe, by K. Schu-
mann ; they also form the completion of the fourth volume of this grand work.
There is a fine heliogravure plate and 31 illustrations, comprising 299 figures.

Introduction to the Study of Fungi : Their Organography,
Classification, and Distribution for the Use of Collectors. By M. C. Cooke,
M.A., LL.D., A.L.S., etc. etc. 8vo, pp. x.— 360. (London: A. and C.
Black. 1895.) Pi'ice 14/-

Owing to the rapid advance in the knowledge of the life-history and deve-
lopment of the Fungi during the past ten years, and especially the large scheme
of classification carried out by Prof Saccardo, it is essential that a guide and
introduction should be prepared and published for the use of students, which
should treat the subject more after the manner of a text-book, adapted to the
illustration of recent discoveries, and an explanation of the methods of classifi-
cation. As such, we feel sure the volume will be welcomed by the student.
There are 148 illustrations, glossary, and index.

REVIEWS. 105

An Introduction to the Study of Seaweeds. By George

Murray, PMx.S.E., F.L.S., etc. Crown Svo, pp. xvi. — 271. (London:
Macmillan and Co. 1895.) I'nce 7/6.

Modern research has completely changed the whole aspect of the study of
seaweeds. In the work before us the author has described only what he has
personally verified by examination, or by the inspection of the original account.
The arrangement of the sub-classes is in the following order : — The Phiiopliy-
ccir, with its familiar forms of sea-wracks and tangles form the first sub-class ;
the Chlorophyceie and Diatomacecv follow ; the Rhodophycea next make a
series by themselves ; and lastly, the simple Cyanopliycea. There are eight
beautifully coloured plates and eighty-eight other illustrations.

Handbook of Grasses. By William Hutchinson. Cr. 8vo,
pp. 92. (London : Swan Sonnenschein & Co. 1895.) Price 2/6.

Treats of the Structure, Classification, Geographical Distribution, and
Uses of Grasses. It also describes the British Species and their Habitats, and
is an endeavour to popularise the study of grasses, the peculiarities of their
structure, and terms employed in describing these plants are carefully explained ;
the chapter descriptive of the British species and their habitats is arranged with
special regard to convenience in field work. Definite information is also given
regarding the geographical distribution of grasses and their vast economic
importance. A very useful book. There are 40 good illustrations in the text.

Analytical Key to the Natural Orders of Flowering Plants.
By Franz Thonner. Cr. Svo, pp. 151. (London : Swan Sonnenschein and
Co. 1895.) Price 2/-

In this work the author chooses, for the determination of genera, distinc-
tive features, preferring those which are visible to the naked eye at the time of
flowering.

Ferns : British and Foreign. By John Smith, A.L.S. New
and enlarged edition. Cr. Svo, pp. xv. — 450. (London : W. H. Allen.
1895.) Price 7/6.

This useful work gives the history, organography, classification, and enu-
meration of the species of garden ferns, with a treatise on their cultivation — e.g..
Special or pot cultivation ; Natural cultivation ; Wardian-case cultivation and
propagation. There are also a General Index of Genera, Species, Synonyms,
and an Index of Special Terms, and a great number of illustrations.

Random Recollections of Woodland, Fen, and Hill. By
J. W. Tutt, F.E.S. Second edition. Crown 8vo, pp. 256. (London:
George Gill and Sons. 1895.) Price 2/6.

Mr. Tutt has given us a delightfully written little book dealing with natural
history subjects and country scenery. We can cordially recommend it as a
reading book for our young friends, and trust it will lead many of them to
observe for themselves some of the wonderful things in Nature by which we
are surrounded. There are more than 100 good illustrations.

Half-Hours with the Stars. By Richard A. Proctor, B.A.,
F.R.A.S., etc. New edition, revised and corrected. 4to. (London: W. H.
Allen. 1896.) Price 3/6.

We have, to give the full title, A Plain and Easy Guide to the Knowledge
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Great Astronomf.rs. By Sir Robert S. Ball, D.Sc, LL.D.,
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In the handsome work before us the author has presented the Hfe of each
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The Zoo (Fourth Series). By the Rev. Theodore Wood,
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Treats of a great number and variety of water-loving Birds and Reptiles.
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Charles Lyell and Modern Geology. By Prof. T. G. Bonney,
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In this work the author shows how Charles Lyell studied, how he worked,
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pp. 128. (Lynn, Mass., U.S.A. : Bubier Publishing Co. 1895.)

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The Story of the Earth in Past Ages. By H. G. Seeley,

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A reprint of a Discourse delivered at the Royal Institution of Gt. Britain,
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An Elementary Treatise on Heat. By Balfour Stewart,

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We have here the facts and principles of the .Science of Heat. The author
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A Manual, OF Physics ; being an Introduction to Physical
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A very amusing and instructive book. The explorations take the reader
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Annual of the Universal Medical Sciences : A Yearly

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1895-)

The eighth annual issue of this voluminous and now well-known work
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Physiology. By A. Macalister, LL.D., M.D., F.R.S., F.S.A.,

etc. i2mo, pp. 123. (London: Society for Promoting Christian Knowledge.
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One of the "Manuals of Elementary Science" Series, and gives in a
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Simple Methods for detecting Adulterations. By John

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This useful little book contains a series of samples for experiment, and
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Helps to Health and Beauty. By a Pharmaceutical Chem-
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Maps in ordinary use are too much crowded with names and details to
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REVIEWS. 109

The Diseases of the Will. By Th. Ribot. Translated
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In treating of the diseases of the will, the author proposes to study its
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At the conclusion of this study he shows that in every voluntary act there are
two entirely distinct elements : one, the state of consciousness ; the other, a
very complex psycho-physiological mechanism in which alone resides the power
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The Origin and Nature of Man. By S. B. G. McKinney.

Cr. 8vo, pp. 95. (London : Elliot Stock. 1895.) Price 3/6.

This little book is divided into two parts: I., Analysis ; II., Intuition.
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of indefinite phantoms among an infinite variety of descending forms, ignorant
of any object or function to justify our existence, and with no hope of certain
knowledge regardir>g either our past condition or concerning our future state."

Le Cure du Benizou, avec Illustrations Photographiques
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The object of this book is doubtless primarily to show the fine photographic
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The Rose-Bud Annual. 4to, pp. viii. — 192. (London :
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Nearly 250 capital illustrations, and a great number of funny and interest-
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This is a charming book, and gives in a most interesting manner eight
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The Apocrypha. Crown 8vo, pp. 147. (London: Samuel
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As we never find the Apochrypha bound up with our modern Bibles, we
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The Illustrated Guide to Great Yarmouth, including
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This little illustrated guide gives a full description of the East Anglian
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The British and Colonial Druggist's Diary, 1896. 4to.
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Besides a useful interleaved diary, in which a page is allotted to each week,
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110 REVIEWS.

The Chemist's and Druggist's Diary, 1896. 4to, (Lon-
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This well-known annual contains, besides the diary (an interleaved page for
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The Boy Skipper ; or, " I have only done my duty." By
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This is an interesting and true account of the hero, William Shotton, who
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stead during the terrible voyage from Java to Melbourne. The illustrations are
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Queen Victoria's Dolls. By Frances H. Low. Illustrated
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Here are nicely coloured pictures representing 75 Oi" Queen Victoria's dolls,
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part of this century, but an abiding study of her imaginative fancy."

Everybody's Illustrated Book of Puzzles. 8vo, pp. 122.
(London: Saxon and Co.) Price i/-. — Very amusing and entertaining.

The Tallerman-Sheffield Patent Localized Hot-Air Bath.

Svo, pp. 51. (London : Bailliere, Tindall, and Cox. 1895.)

Describes a new Invention for the Treatment of Rheumatism, Gout,
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On Memory and The Specific Energies of the Nervous System.
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A New English Dictionary on Historical Principles. Edited
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These two parts, which were published simultaneously in October, contain
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Hazell's Annual for 1896 : A Cyclopedic Record of Men

and Topics of the Day. Edited by W. Palmer, B.A. Cr. 8vo, pp. 678.
(London: Ilazell, Watson, and Viney. 1896.) Price 3/6.

This is the eleventh year of issue of this valuable Annual, which contains
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tory I^egislation. We tind also articles upon the Royal Commission and
Committees on Secondary Education, Joint Stock Companies, Opium, Indian
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changes are fully described. We have Biographies of the Members of the New
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to date. Four new Maps of Indo-China, the Valley of the Upper Nile, the
Pamirs, and Sierra Leone, have been added ; making the Annual one of the
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The Oracle Encyclopedia, containing most accurate infor-
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This is an exceedingly cheap and most useful publication. Each part
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The Royal Natural History. Edited by Richard Lydek-
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This fine work has reached to Part 26. In Part 25, commencing the 5th
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The December part of this important periodical contains : Williamson's
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At the moment of going to press we received the part for January, 1896.
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Mr. L'Estrange Ewen has discovered varieties and peculiarities in our
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4/- the year, post free.

[ 113 ]

®n 6ome iProtcin Cr^stalloiba an^ their

probable IRelation to the IRutrition

of the pollen«*^ube.

By Lily H. Huie, Hollywood (Edinburgh).
Plate V.

Y the use of special fixing and staining methods,
Zimmerman* has, during the last few years, greatly
extended our knowledge of Protein Crystalloids ;
and Stock, t using the same methods, has recently
investigated their relation to the metabolism of the
plant. Apart altogether from those found in
aleurone grains. Protein Crystalloids may be clas-
sified according to their position in the cell as —
I. — Nuclear Crystalloids.
2. — Cytoplasmic Crystalloids.
3. — Cell-sap Crystalloids.
4. — Chromatophoric Crystalloids.

Nuclear Crystalloids.- — Zimmermann has found that, in the
nuclei of Pteridophyta and Angiosperms, Protein Crystalloids are
of much more frequent occurrence than was formerly supposed.
He has found them in a very large number of Ferns and in 47
species of Phanerogams belonging to ten different families.

Cytoplasmic Crystalloids occurring in the body of the cell have
been demonstrated only in a very limited number of instances.
Much difficulty has been experienced by observers in determining
whether such crystalloids really occur in the cytoplasm or in the
cell-sap, because of the thickness of their sections. Up till now,
in one instance only — that of the potato tuber — have protein

* Zimmermann, Beitrage zur Morphologic unci Physiologic dcr PJianzen-
zelle. Heft I., p. 54, and Heft H., p. 112.

t Stock, Ein Bcitrag zur A'cnnhtiss der Proteinkry sialic ; Cohn's Beitrage
zur Biologic der PJlanzen., Bd. 6, 1892.

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. i

114 ON SOME PROTEIN CRYSTALLOIDS.

crystalloids been proved to be in the cytoplasm. Those which
form the subject of the present paper are also cytoplasmic, and
are found in Scilla patula^ etc.

Cell-sap Crystalloids. — Under this head it is convenient to
group all other known instances of crystalloids occurring in the
body of the cell (ii in all, according to Zimmermann), since, with
the exceptions just mentioned, whenever their true position has
been investigated, they are said to have been found in the Cell-sap.

Chromatophoric Crystalloids. — Schimper * has already carefully
studied the protein crystalloids of Chromatophors, and enumerated
the instances of their occurrence, and Zimmermann has extended
his researches in this direction.

Methods.

Fortner methods. — Zimmermann and Stock fix the material
preferably in a saturated solution of corrosive sublimate in abso-
lute alcohol ; embed in paraffin and cut sections, which vary in
thickness from 5 to lo m- The sections are left for twenty-four
hours or more in a o'2 per cent, solution of Saure-fuchsin in dis-
tilled water; washed out in running water until sufficiently
decolourised ; dehydrated with absolute alcohol, cleared up in
xylol, and mounted in xylol-balsam.

Though both histologists have endeavoured to find other
methods for the successful demonstration of these bodies, they
have not succeeded in doing so, and come to the conclusion that
Saure-fuchsin acts as a specific stain.

My methods. — The ovaries of Scilla patula were fixed by me
in three different ways : —

I. — In absolute alcohol.

2. — In Mann's Picro-corrosive Alcohol,t which consists of a
saturated solution of corrosive sublimate and picric acid in abso-
lute alcohol.

3. — In Mann's Watery Corrosive Fluid. J

* Schimper, Untersuchungen iiber die Chlorophyllk'drper, und die thne7i
homologen Gehilde, Pringsheim's Jahrbuch, Bd. 1 6, p. i.

tMann, Trans. Bot. Soc. Edin., vol. xviii., pp. 429, 432, 1890.
XJourn. Scot. Micro. Soc, 1894, p. 155.

ON SOME PROTEIN CRYSTALLOIDS. 115

To a boiling 07 5 per cent, common salt solution, sublimate is
added to saturation (12 grm. for 100 cc). 'Hie solution is then
allowed to cool, when crystals of sublimate make their appearance.
Preserve the solution without decanting (M. Heidenhain).

Martin Heidenhain's corrosive sublimate solution, 100 cc. : —
Picric Acid ... ... ... i grm.

Tannic Acid ... ... ... i grm.

(The Tannic Acid may be omitted if preferred.)
Material fixed in absolute Alcohol gives, however, poor results
with the stain I employed, and requires very great care in the
decolourising process. The picro-corrosive alcohol gives much
better results, but the material which stained most successfully
was fixed by the watery picro-corrosive.

The tissues were carefully dehydrated, and taken through
Chloroform into Parafiin, and serial sections cut not thicker than
2 — 3 A*. Sections of this thinness permit the exact position and
the details of the conglomerate crystalloids to be determined with
the greatest facility.

The paraffin sections were spread out on warm water (40 — 45^
C), after Gulland,* and fixed to the slide by Mann's albumen
method,! and then stained in Mann's Methylblau-Eosine mixture
as follows : —

Reqiiisites : — The Staining Fluid.
a. — I per cent, methylblau in distilled water ... 35 cc.
I per cent, water-soluble eosin in distilled

water ... ... ... 45 cc.

Distilled water ... ... ... 100 cc.

b. — I per cent, caustic soda solution in absolute alcohol.
The Methylwasserblau (C37 H26 N3 S3 O9 Na3) was
obtained from Dr. Griibler, Leipzig.
Method : —

I. — Stain for twenty-four hours.
2. — Rinse the dark blue sections in ordinary water.
3. — Dehydrate thoroughly with absolute alcohol.

* Gulland, ybwrw. of Anat. and Physiol., 1891, p. 56.

t Mann, "A New Fixing Fluid for Animal Tissues," Anat. Am., Jahrg.
viii., 1893, Nos. 12—13, P- 442, dXiAJourn. Scottish Micro. Soc, 1894, p. 161.

116 ON SOME PROTEIN CRYSTALLOIDS.

4- —Transfer the slide to a vessel containing absolute alcohol,
30 cc, and i per cent, caustic soda solution in absolute alcohol,
4 drops. Wait till sections are of a rust colour.

5. — Remove all traces of caustic soda with absolute alcohol.

6. — Rinse sections in ordinary water for one minute. Red
clouds are given off and the sections become bluish.

7. — Place slides for two minutes into water slightly acidified
with acetic acid. This is done to deepen and fully restore the
blue colour and also to fix the eosin.

8. — Dehydrate, clear with xylol, not clove oil, and mount in
turpentine-balsam.

For results see Figs, i — 14.

By using simply a | per cent, watery solution of eosin, and
decolourising with alcoholic caustic soda in the way detailed above,
I succeeded in staining the crystalloids, but the result is inferior to
that produced by the contrast of the double stain. Other acid
dyes were tried with less success, Magdala-rot (echt) giving the
next best results.

I have used Mann's stain for the crystalloids in the aleurone
grains of the seeds of Ricimis, with beautiful results. I have also
examined the tissues of various plants in which Zimmermann
finds protein crystalloids, both with Mann's stain and with the
Saurefuchsin, with the result that whenever I succeeded with the
one method in demonstrating them, I succeeded also with the
other ; and whenever I failed with the one stain, I failed equally
with the other.

Comparing Zimmermann's method with the one I employed, I
certainly prefer the latter because of the great preciseness with
which crystalloids are stained.

Cytoplasmic Crystalloids of Scilla patula and Hyacinthus Sp.

While examining the ovaries of Scilla patiila with the help of
the Methylblau-eosin double-stain, my attention was arrested by
numbers of bright red granules and crystalloid bodies in the cyto-
plasm of the unicellular hairs, that occur in considerable numbers
on the placentas in this and other species of Scilla. From their
resemblance to many of Zimmermann's figures, it at once occurred

ON SOME PROTEIN CRYSTALLOIDS. 117

to me that these bodies were protein-crystalloids. Proceeding to
test them I found —

They have a higher refractive index than the cytoplasm.

Iodine colours them darkly.

By Zimmermann's method of staining they were well shown,
but not unless the sections were of a thickness of at least 7 fi,
which is a disadvantage for minute cytological work.

The hairs in which the crystalloid bodies occur are extremely
numerous immediately above the uppermost ovules, and are more
sparsely distributed on the lower portion of the placenta.

1 have studied them from the time when they are first differ-
entiated from the- surrounding epidermal cells, till the withering of
the flower, when they degenerate. In young ovaries (about three
jnillemeires in length, including the pistil), the upper ovules of
which show four nuclei in the embryo-sac, the hairs are only
slightly larger than the other epidermal cells (Fig. i, a), and are not
specially rich in cell protoplasm, although the nucleus stains
deeply.

In ovaries five millemetres long, at the time when the embryo-
sac first contains eight nuclei, the hairs have elongated greatly and
are remarkably rich in protoplasm, and in nuclear chromatin, and,
with few exceptions, each hair possesses several (2 — 6) nucleoli
(Figs. 2 and 3). At this period any appearance of erythrophilous
bodies outside the nucleus is extremely rare. A few hair-cells may
have undergone division ; but, as a rule, they continue to be uni-
cellular throughout life. Dumb-bell shaped nuclei (Fig. 3) are
very common, both at this period and later. I examined 50 cells
of this stage, making careful drawings of each serial section, and
found that there were as follows : —

Hairs with three to six nucleoli ... 14

Hairs wifh two nucleoli ... ... 24

Hairs with one nucleolus ... ... 12

Only two cells of the total number contained crystalloids or
granules ; and these occurred in the lower, better nourished, and
therefore more mature part of the ovary. One of them had one
nucleolus ; and the other contained two.

On the examination of the ovary of a bud about seven jnille-
metres lo?ig, numbers of erythrophilous granules and slender

118 ON SOME PROTEIN CRYSTALLOIDS.

crystalline rods are found in the cytoplasm. I believe the gran-
ules are also crystalline in form ; but they are usually so very
small that I have not satisfied myself on this point (Figs. 4 and 5,
cr. and crk.).

Out of fifty cells of this stage examined and drawn, there were
as follows : —

Hairs with more than two nucleoli ... 9

Hairs with two nucleoli ... ... 19

Hairs with a single nucleolus ... 22

Of the twenty-two cells containing one nucleolus, eighteen had
erythrophilous granules and crystalloids outside the nucleus ; two
of the cells with two nucleoli showed them, while the cell with
three nucleoli only exhibited a few granules.

In the ovaries of opening Jiowers the hairs are at their fullest
state of development (Figs. 6 to 9), being often of very large
size (Figs. 8 and 9). They stain intensely blue, owing to their
exceeding richness in protoplasm ; while the crystalloid bodies are
conspicuous from their large size, and the brilliancy with which
they take the red dye. The crystalloids now often resemble at
first sight some of Zimmermann's figures of single large irregularly
shaped ones, but with careful focussing they are seen to consist of
conglomerations of smaller, generally elongated crystals (Figs. 8
and 9, cr.). Long, slender forms also occur singly, and show in
transverse section an oblique rhomboidal outline. Occasionally
they are bent or curved, and not infrequently one may observe
them bordering a vacuole (Fig. 10). I examined and drew fifty
hairs from the ovary of an opening flower, and of these there were :
Cells containing more than two nucleoli .. i
Cells containing two nucleoli ... 7

Cells containing a single nucleolus ... 42

All these cells, except one containing two nucleoli, had gra-
nules and crystalloids in great profusion. The cell with three
nucleoli has been represented in Fig. 8, and two of its nucleoli are
seen to be very small.

In fertilised ovaries, when the ovule has undergone its first
division, the few hairs which still retain their normal size and shape
show some crystalloids ; but the protoplasm and nuclei begin to
exhibit the characeristtic affinity of degenerating cells for acid

ON SOME PROTEIN CRYSTALLOIDS. 119

dyes, for they stain of a purple colour (Figs, ii and 13, a). Most
of the hairs, however, are entirely red. Figs. 12 and 13, <^, contain
large vacuoles in the protoplasm (Fig. 12, v.), and also in the
nucleus {nv.), and possess few or no crystalloids. Some of the
hairs are quite withered and shrivelled up (Fig. 13, b). I have
several times observed, lying in the loculi of ovaries of this age,
groups of crystalloids discharged by withered hairs (Fig. 13, c).
Sometimes the entire shrunken hair remains in close proximity to
the crystalloids ; at other times, as in Fig. 13, only a few traces of
protoplasm,/^., are discernible about the group, looking as if a
large hair had burst.

The gradual increase in quantity of the cytoplasmic, and cor-
responding diminution of nucleolar erythrophilous matter, would
seem to point to some relation of the crystalloids to the nucleolus,
which latter has been regarded by some authors as a storehouse of
nourishment.

Stock has further shown that protein crystalloids are deposits
of reserve albumen, and Green* has lately examined the style of
the lily, and states that " The distribution of nutritive mate-
rial, especially starch, in this organ was found to have a very
definite relation to the progress of the pollen tube ; " and further,
" The nutrition of the tube is a process in which the grain itself,
and the tissue through which it grows take a part, both contain a
reserve material and enzymes."

May it, therefore, not be that the function of the placental
hairs, so rich in protoplasm and crystalloids, is to nourish and thus
to guide the pollen tube ?

A parallel chain of facts to that furnished by the life-history of
the hairs is given by those epidermal cells lining the three slits
which are placed symmetrically in the tissue of the ovaries, and
are formed by the upper surfaces of the three carpellary leaves
failing to unite at these places. In young buds these cells show
several nucleoli, frequently six. In older stages the nucleoli
diminish in number to one, which latter is often so diminutive as
to be all but imperceptible ; at this time minute hexagonal crystal-
loids make their appearance in the cytoplasm (Fig. 14, cr.). Out

* Green, Annals of Botany, June, 1S94.

120 ON SOME PROTEIN CRYSTALLOIDS.

of fifty such cells examined in the ovary of a bud of 5 millemetres
in length there were : —

Nuclei with more than two nucleoli ... 19
Nuclei with two nucleoli ... ... 26

Nuclei with only one nucleolus ... 5

None of them showed erythrophilous bodies external to the
nucleus. Out of fifty cells from the ovary of an opening flower
there were : —

Nuclei with more than two nucleoli ... o
Nuclei with two nucleoli * ... ... 6

Nuclei with only one nucleolus ... 44

All these cells showed the little crystalloids.
Undoubtedly, in this case, the number of nucleoli in the indi-
vidual cells is diminished to some extent by cell multiplication :
and, if there is really any connection between the crystalloids and
nucleoli, this may account for the small size of the crystalloids in
these cells.

Belong long I hope to carry out some investigations on living
material ; and also to extend the research to the ovaries of allied
plants. The only one of these, which, owing to the time of year,
I have been able to procure as yet — Hyacinthus orientalis albulus —
was forced in a greenhouse, and shows in the hair-cells of a mature
ovary, and in some other cells of the ovarian wall cubical crystal-
loids like those of the potato tuber, but 1 have not had the oppor-
tunity of investigating the history of these crystalloids as yet.

In conclusion, I gladly avail myself of this opportunity to
acknowledge my deep obligation to Dr. Gustav Mann for his
constant and invaluable help throughout the preparation of this
paper.

EXPLANATION OF PLATE V.

Ml the figures were draimi with the help of Zeiss' s camera lucida, the
paper being placed on the table and inclined at an angle of 20°. Except
for Figs. 1 and 13, Leitzs l/12th oil immersion objective teas used ivith
Zeiss's No. 4 ocular. For Figs. 1 and 13 Leitzs l/12th oil immersion
objective with Zeiss s ocular No. 2 was employed.

List of Abbkeviations. — a, Cell showing senescence. 6, Withered
cell, c, Burst cell, pr.. Protoplasm, h., Nucleus, vd. Nucleolus,
e., Endonucleolus. ■)?., Vacuole, n.y., Nuclear vacuole, cr. , Crystal-
loid, crli. , Granular crystalloids.

Joumaj of Microscopy, 3^'^ Ser. Vol. 6, Plate 5.

Fi6 1 a. _

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rig. 7.

5 \fc

Tl.-_»

11 -1-411 J

/••'' •■-1 .«

:r:---

nl

\ Fig. 14^.

Fi^.l2.

ZT<--

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\

Ci/top^lcismxc Cri/stalloids of ScillaPatulci.

Journal of Microscopy, 3"^^ Ser, Vol. 6. Plate 5.

^ .-,,^;f crk.

I'C . -"-*- ' • ^ .•'••1

CytopLasmLC Crystalloids of SoUIcl PaUola^.

ON SOME PROTEIN CRYSTALLOIDS. 121

Fig. 1. — From young ovary, 3 millenietres in length. Hair cell, a, at
the stage when it is first distinguishable from other epi-
dermal cells.

,, 2 — 3. — Hairs from ovary, 5 millenietres long. No erythrophilous
bodies outside the nucleus. Fig. 2 shows 4 nucleoli in
the nucleus. Fig. 3 exhibits characteristic dumb-bell
shaped nucleus, containing 3 nucleoli.

,, 4—5. — From an ovary 7 millenietres in length. Fig. 4 is a very
typical hair-cell of this stage, with numerous small ery-
throphilous granules in the cytoplasm, crk. Fig. 5 shows
slender crystalloids, cr., as well as granules, cr-k.

,, 6— 10.— Mature hair-cells from the ovary of an opening flower.
Fig. 6, the nucleus has a peculiar, almost pear-shaped
outline ; 9 small crystalloids are seen in the cytoplasm.
Fig. 7 shows a group of large and small elongated crys-
talloids. Fig. 8 shows a nucleus with 1 large and 2 small
nucleoli, one of which is close to the periphery of the
nucleus. There is a conglomerate mass of crystalloids in
the cytoplasm, and also a few small scattered rods and
granules. Fig. 9, Hair-cell with one conglomerate group
of large crystalloids, and exhibiting marked vacuolation
of the cytoplasm, v. Fig. 10 shows a large vacuole, v.,
siuTounded by crystalloids.

,, 11 — 13. — From an ovary in which fertilisation had taken place,
and the ova of which in most of the ovules had under-
gone their first division. Fig. 11. — Large hair-cell, in
which the protoplasm and nucleus have commenced to
degenerate ; crystalloids are still present. Fig. 12. —Very
long hair, with degenerated protoplasm. There is a very
large vacuole in the cytoplasm, v., and the nucleus is also
vacuolated, n.v., while the nucleolus has a large single,
centrally placed endonucleolus, e. Two crystalloids lie
in the cytoplasm. Fig. 13 shows a partially degenerated
and much vacuolated hair-cell, a ; a completely withered
hair, b ; and a group of crystalloids, c ; which have been
discharged by a withered cell, the latter being repre-
sented only by vestiges of cytoplasm, pr., and nucleus, n.

,, 14. — Cell from dorsal epidermis of carpellary leaf, containing
small rhomboidal crystalloids.

[ 122 ]

Qn tbe 1Rcw (Baeee— Hrcjon aub Ibelium.

By G. F. Hardcastle,
Assistant in the Chemical Dept. Hudd. Tech. College.

ARGON.

DURING the last three or four years, Lord Rayleigh, the
well-known physicist, has been engaged in the determina-
tion of the densities of various gases. The method he
used was the one used by Regnault, viz., weighing the gas con-
tained in a large glass globe. Nitrogen was one of the gases whose
density he determined. He obtained his nitrogen in the first
case by bubbling air through liquid ammonia, and then passing
it through a red hot tube. The excess of ammonia was absorbed
by acid, and the water by ordinary dessicating agents. He then
weighed the nitrogen obtained from air by absorbing the oxygen
with red-hot copper. The nitrogen by this latter method was
found to be one-thousandth part heavier than that by the former
method. He afterwards performed several experiments with nitrogen
derived wholly from ammonia and other chemical compounds.
This nitrogen he called " chemical " nitrogen, in distinction to
" atmospheric " nitrogen, or that derived from air. The results of
these experiments showed that atmospheric nitrogen was about '5
per cent, heavier than chemical nitrogen. The following figures
represent the actual weights in grams of the globe full of gas, which
he obtained in these experiments : —

Atmospheric Nitrogen. Chemical Nitrogen.

By hot copper - - - - 2'3i03 From nitric oxide - - - 2*3001

,, hot iron 2"3ioo ,, nitrous oxide - - - 2*2990

,, ferrous hydrate - - 2'3io2 ,, ammonium nitrite - 2*2987

These results seemed to suggest that there is in atmospheric
nitrogen some other constituent heavier than true nitrogen. Caven-
dish had also noticed in his experiments that, after sparking the nitro-
gen of the atmosphere with oxygen for a long time, there was a small
residue amounting to about i/i2oth of the original nitrogen. He
did not examine the matter any further, but stated that if any other
body was present than nitrogen, it was not there in greater quantity

ARGON AND HELIUM. 123

than i/i2oth of the nitrogen. At this point Lord Rayleigh was
assisted in his investigations by Prof. Ramsay. They succeeded
in isolating the heavier constituent of atmospheric nitrogen, to
which they have given the name of " Argon." One of the
methods used by them for this purpose was the same as that used
by Cavendish. They used a very powerful induction coil and
alternating dynamo currents. The air was mixed with oxygen,
and sparked for several hours in contact with strong caustic alkali.
The excess of oxygen was removed by ordinary methods. The
other method which they used was to remove the oxygen from air
with red-hot copper, and then absorb the nitrogen by red-hot
magnesium.

Separation of Argon on a large scale. — To prepare argon on a
large scale a quantity of air was first freed from oxygen by means of
red-hot copper, and the atmospheric nitrogen remaining was stored
in a gas-holder. The gas was passed from the gas-holder through
sulphuric acid to indicate the rate of flow, and then dried over soda-
lime and phosphorus pentoxide. It then passed through a com-
bustion tube packed with magnesium turnings and heated to
redness in a furnace. The current of gas and heat were carefully
regulated so as not to soften the glass tube. The gas was then
passed over a mixture of copper and copper oxide, again over soda-
lime and phosphorus pentoxide, and then into a system of tubes
containing red-hot magnesium turnings. It was kept circulating till
no further absorption took place, and was then pumped out of the
tubes and transferred to a mercury gas-holder. The removal of the
last portions of nitrogen is very slow, but circulation for two days
usually effects it, as far as can be shown by the spectrum. As this
test will show the presence of i^A per cent, of nitrogen it is
certain that the argon so obtained did not contain more than i ^
per cent, of nitrogen. The oxygen method is the slower one of
the two, but at the same time it requires less attention than the
magnesium one. If an alternating current can be readily obtained,
then the oxygen method would be the easier to work.

Properties. — That argon is a very inert gas is proved by the
method used for its isolation. Nitrogen itself is generally considered
inert, but it will combine under certain circumstances with oxygen
and magnesium, whereas argon will not. Titanium at a red heat

12 4 ON THE NEW GASES —

has a great afifinity for nitrogen, but argon does not combine with
it. Berthelot states however that, under the influence of a silent
electrical discharge, argon will combine with benzene vapour. Argon
prepared by both the oxygen and magnesium methods has about
the same solubility in water as oxygen, and is 2^ times as soluble as
nitrogen. The fact that argon is more soluble in water than nitrogen
would lead one to expect an increased proportion of it in the dis-
solved gases of rain-water, and this has been proved by experiment.
The spectrum of argon has been examined carefully by Mr.
Crookes, and is different to that of any known element. The
light of the electrical discharge in argon is under some circumstances
red, and under others blue. The density of argon has been
determined, and found to be 19-9. The ratio of the specific
heats of argon as determined by Prof. Ramsay is represented by
the number i'65, which is very close to the theoretical limit i-66.
Hence it follows that argon is monatomic. The presence of argon
in the atmosphere has also been proved by atmolysis. The
atmolyser used was made by combining a number of church-
warden tobacco pipes. These were enclosed in a glass tube so
arranged that the outsides of the tobacco pipes could be kept
in a partial vacuum. Air was drawn slowly through by means of
a bottle aspirator filled with water, and so regulated that only
two per cent, of the air entering the pipes reached the outlet.
The residual gas, after the removal of oxygen and water, was
found to be considerably heavier than atmospheric nitrogen.

Argon is not present in the nitrogen derived from chemical
sources. To show this fifteen litres of nitrogen prepared from
ammonium nitrite were treated in exactly the same manner
as the atmospheric nitrogen by the oxygen method. The
residue amounted to 3'5 c c, whereas if atmospheric nitrogen had
been used it would have been 150 c.c. But if chemical nitrogen
contains no argon how is it that there were 3*5 c.c. of argon left ?
The source of this is to be sought for in the large quantities of
water used in the manipulation of the large amount of gas under
treatment. Argon is somewhat soluble in water, and, during the
process, no doubt some of it will be evolved.

Argon has been liquified and even solidified by Prof. Olszewski.
The sample of gas which he experimented with was very pure, and

ARGON AND HELIUM. 125

had been prepared by the magnesium process. It showed no trace
of nitrogen when examined in a vacuum tube. It boils at

— i86-9''C, and melts at — i89-6°C. Its critical temperature is

— i2i°C, and critical pressure 50-6 (?) atmospheres.

Then we come to the question, What is argon ? Is it an
element, mixture, or compound ? The ratio of the sp. heats shows
that it is a monatomic element, or a mixture of monatomic ele-
ments. Again, the fact that it possesses both a definite boiling-point
and melting-point would seem to indicate that it is not a mixture.
On the other hand, argon has two spectra which can be separated
to some extent in a vacuum tube (Crookes), and this appears
to show that argon is a mixture. This fact is not quite so
definite as the other two. If argon is a monatomic element its
atomic weight will be about 40.

HELIUM— A Constituent of certain Minerals.

Soon after the discovery of argon. Prof. Ramsay, while trying
to find some substance which would combine with that gas, came
across a paper by Hillebrand. In this paper it was stated that on
boiling uraninite with dilute sulphuric acid a gas was given off which
proved to be nitrogen. On trying the experiment he found that only
ten per cent, of the gas was nitrogen, and the rest was a new gas.
His further ex|)eriments were carried on with the same gas obtained
from cleveite. On examining by means of the spectroscope he found
that the gas consisted of argon along with a totally new gas. In
the spectrum of this new gas was seen a bright yellow line, coinciding
with the line D3 in the solar chromosphere, and attributed to the
hypothetical element termed helium in 1868 by Profs. Lockyer and
Frankland. The investigation of this has been carried on by Prof
Ramsay, assisted by Dr. Collie and Mr. Travers.

Terrestrial Sources of Helium. — The method of obtaining the
gas from these minerals was as follows : — The mineral (two to five
grms.) was coarsely powdered and heated in a hard glass bulb,
which had previously been exhausted. Any water and carbon
dioxide were absorbed by soda-lime and phosphorus pentoxide.
Then the gas was sparked with oxygen to remove hydrogen, and the
excess of oxygen was absorbed by alkaline pyrogallate. For spectro-
scopical analysis the gas was transferred to a vacuum tube by means

126 ON THE NEW GASES — ARGON AND HELIUM.

of a Topler's pump. They also examined the gases obtained
from many other minerals by means of the spectroscope, and
their spectra are identical with the spectrum of helium from
cleveite. From a careful examination of these minerals it seems
that the helium is retained by those consisting of salts of
uranium, yttrium, and thorium. The three principal minerals
which are available as sources of helium are cleveite, uraninite,
and broggerite.

Properties. — -In many cases sufficient helium could not be
obtained in order to ascertain its density. Sufficient gas, however,
has been obtained from cleveite and broggerite to enable the
density to be determined. The maximum density of the original
gas from cleveite was 3 "89. This sample contained a little nitrogen.
In these determinations of the density of helium the utmost care was
taken to get the gas pure from nitrogen, carbon dioxide, sulphur
dioxide, sulphuretted hydrogen, and hydrogen. The density of the
gas got from broggerite by fusion with potassium bisulphate was
taken, and also of the gas from cleveite. The following figures
were obtained : —
Gas from broggerite by heating ... ... 2-152

„ ,, „ ,, potassium bisulphate 2'i87 oxygen = 16

„ „ cleveite ... ... ... 2*205

Mean. 2t8i
The wave length of sound in helium was measured, and from this
the ratio of the sp. heats was calculated. This was found to be i "65 2,
which comes near the theoretical number i-66. This gas had
a density of 2'i33. Hence helium is monatomic. It is not attacked
by oxygen under the electric discharge, nor is it oxidised by red-
hot copper oxide. Red-hot magnesium does not affect it. It is
sparingly soluble in water. At 18'^C i vol. water dissolves '0073
vol. helium. It is altogether insoluble in alcohol and benzene.
In the spectrum of helium there are two lines in the red which
are coincident with two of the argon lines. A close analogy exists
between argon and helium. Both are monatomic, if we draw
the usual inference from the ratio between their sp. heats. If
we assume that this inference is correct, then it follows that their
atomic weights are identical with their molecular weights. The

REMARKABLE EYE-STRUCTURE IN A FISH. 127

molecular weight is twice the density; hence for helium the
molecular weight and also the atomic weight is 2-13 x 2 =
4-26. This is again on the assumption that helium is an element
and not a mixture. If the atomic weight of argon is 40, then
there is no place for it in the periodic system. It has not yet been
proved that it is not a mixture. From the spectra it seems that
each gas has a common ingredient. The density of helium does not
leave much room for the presence of a large quantity of a heavier
constituent. To fit the periodic system the density of argon should
be diminished by the removal of a heavier constituent, rather than
increased by the removal of a lighter one. Again, assuming that
the other constituent of argon, if there be one, is a heavier one,
and that helium contains the same, then, even if it be present
in a very small quantity, it will reduce the density of helium
considerably, and consequently bring it much nearer to that of
hydrogen.

IRemarkablc JB^^c^^^tvnctxnc in a JTt^l^

MR. W. Tegetmeier has recently called attention to a fish,
which is very curious as regards the organisation of its
eyes, of which, like its congeners, it has two, although it
well merits the name {tdraophthalmus) that attributes four to it.
This fish has extremely bulging eyes, and when it is swimming
upon the surface, as is its custom, half of the eye is above the
surface of the water and the other half beneath it. Even exter-
nally, something abnormal is observed in these eyes. In fact,
from the conjunctiva there starts a horizontal band of a dark colour
that divides the eye into two parts — an upper and a lower. But
the division is more profound still. There is a sort of halving of
the pupil so as to form two — an upper and a lower — to which cor-
respond a common iris that tends to a division, in the sense that
a fold of this membrane separates the upper iris from the lower.
But all this would not permit the animal to see in the air as well
as in the water, were there not added a special arrangement of the
crystalline lens. The crystalline of terrestrial animals has the
form of a lens, but, in order to see in water, it requires a nearly

128 INTELLIGENCE IN ANTS.

spherical one. The Anableps possesses both such forms. Mr.
Stewart, who has carefully dissected the optical organ of this
curious fish, shows that the crystalline lens itself is likewise halved,
the upper part being lenticular, while the lower part, beneath the
conjunctival band, is nearly spherical. There is, therefore, in this
case a very marked adaptation, the upper part of the eye being
adapted for vision in the air, and the lower part being conformable
to the type required for vision in water. It is very probable that
the structure of the upper half is acquired, although it would be
difificult to prove the fact. Perhaps such adaptation might be
made to disappear by causing the fish to live entirely under water.
— Scientific A merica n .

3nteUioencc in ante.

THE January number of Revista Brasileira, a monthly maga-
zine recently started in Rio Janeiro, contains an interesting
note upon the intelligence displayed by the so-called
Sauba Ant (probably CEcodoma cepalotes). It seems to be the
general opinion that these ants spare the coffee-trees that grow
about the ant-hills. They enjoy the shade afforded by these
evergreen trees, whose roots penetrate their galleries, and hence
endeavour to preserve them, despoiling only those which furnish
them no protection. The writer of the note referred to witnessed
near Rio an interesting exhibition of the intelligence of these
insects. A " Rosinante," lodged in a stable built of boards, was
being daily defrauded of a portion of his rations by the saubas.
We quote, says Insect Life, from a translation from the Portuguese,
kindly sent us by Mr. J. C Branner : —

" No sooner was the corn put in the feed-trough than the
scouting ants announced the fact, and a line of workers was
immediately established, and, penetrating by the cracks between
the boards, they came out, each one loaded with a grain of corn,
with which it descended on the outside. In this descent there
was a reentrant angle, difficult to cross ; a single worker stationed
itself there and undertook to help the others over. It did this by

THE ORIGIN AND HISTORY OF AGATES, ETC. 129

taking part of the weight of the grain of corn, and backing across
ahead of its companion until it had got it to a safe place. After
helping one it returned to meet another, and continued this
apparently voluntary task as long as this systematic robbery
lasted." — Scientific American.

^bc ©rigin an^ Ibistor^ of IDacietice of Hoate,
jflint, au^ other Siliceous IRobules.

By C. D. Hardcastle, Leeds.

A GATES have been defined as siliceous concretions or con-
IX. cretionary nodules, formed in cavities in the trap and
kindred rocks. They can scarcely be said, however, to be
concretions in the ordinarily accepted meaning of that term.

A concretion — from the Latin con and cresco, to grow together —
is an aggregation of mineral matter of a different kind from the
matrix in which it is embedded, formed round a central point or
line, attracted generally by some organic matter, as a sponge, fern,
leaf, or shell, which frequently remains enclosed, but is sometimes
nearly, if not altogether, obliterated. These may be illustrated by
sponge in flint, Echinus in flint, etc., fern and leaf in Dudley iron-
stone, Ammonite in lias, and Productus in coal measure sandstone.

Agates — as a general rule, at all events — are formed by infil-
tration of silica into cavities in rocks by consecutive layers, laid
on the walls of the cavities in the first instance, and continuing
towards the centre, which is filled up last ; or, perhaps, in some
cases, the cavity is filled up almost at once with colloid silica,
much in the way that a mould is fiUed with metal in casting.
There is no organism enclosed, as in concretions On this account
it has been proposed to call agates secretionary or incretionary
nodules.

Concretions of various kinds are formed in all classes of sedi-
mentary strata from the alluvial sands and clays of recent date, to
the deposits of paloeozoic age. Nodules of carbonate of lime
occur in recent and tertiary clays— jaspers in the sandy clay
deposits of the Nile, and menelite in other tertiary deposits. The

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. l

130 THE ORIGIN AND HISTORY OF

best known are the flints of the chalk, chert of the green- sand and
limestone, and the clay ironstone nodules of the coal measures.
The Egyptian jaspers of the Nile Valley and some flints from the
chalk are frequently called Agates on account of the concentric
and other peculiar markings which they exhibit.

Agates are hard, siliceous nodules of fine texture, transparent
to translucent, formed by the infiltration of siliceous waters into
cavities in various kinds of volcanic and igneous rocks ; and con-
sist, to a large extent, of successive alternate concentric layers of
various kinds of chalcedony, jasper, and opal ; and quartz in the
form of rock crystal and amethyst, and these sometimes are
covered with chalcedony when the cavity has only been partially
filled, as is the case in many geodes (hollow nodules). Speci-
mens may be seen with an outer circle of amethyst and amethyst
crystals on one side of the cavity, and quartz crystals lined with
chalcedony on the other. Many geodes are lined with amethyst
or quartz crystals only. When fresh supplies of siliceous waters
have been continued, the central cavity has been filled by the
quartz crystals on each side, meeting in the centre.

Agates receive different names in accordance with the arrange-
ments of bands, stripes, spots, and clouds of various colours, as
red, green, blue, yellow, white, brown, and black, with which they
are inwardly variegated. Those which have stripes or bands of
various colours arranged in straight parallel lines are called ribbon
agates on account of their resemblance to ribbon. The term,
fortification agate, is applied when the parallel bands assume a
zigzag angular arrangement, somewhat in the form of a fort.

Eye Agate consists of a number of concentric rings of various
colours surrounding a dark central spot, and somewhat resembles
a human eye ; sometimes the circles appear to be sufliciently
round to have been drawn by a compass. I have a fair specimen,
with a reddish-brown iris, surrounded by four alternate circles of
bluish white, and black or very dark brown chalcedony, surrounded
by a band of crystalline quartz.

Moss Agate is a translucent chalcedony, which appears to
include embedded moss, ferns, seaweed, small vegetable filaments,
and other arborescent forms. It is sometimes called tree agate,
and some of the varieties are called Mocha-stone, either from

VARIETIES OF AGATE, ETC. 131

having been formerly supplied by traders from Mocha in Arabia,
or as a corrupted form of the Latin musms through the Italian
vwschos — moss. Eminent mineralogists have differed in opinion
as to whether the markings were due to embedded vegetation or
to mineral infiltrations. The latter opinion now prevails, analysis
failing to detect vegetable substances, while various mineral
matters are traced in the minute cracks and porous portions of the
stone, giving the appearance of ferns, foliage, and moss.

Onyx is banded agate containing bands of two or more differ-
ent colours. If one of the bands be red-carnelian or sard, the
stone is called a sardonyx.

Brecciated Agate. — Some of these stones are very beautiful,
and have the various constituents — Amethyst quartz, chalcedony,
and jasper — being blended so as to produce contrast and harmony
in a pleasing manner. Specimens of these may be seen in
Ruskins' collections at the Sheffield Museum. It is thought by
some authorities that the original agate has been, perhaps, by
some earth movement, faulted, broken into fragments, and
re-cemented by infiltration of silica.

The main constituent of agate is chalcedony, and some agates
are composed entirely of it ; but generally one or more of the
other constituents occur with it. Some agates consist of chalce-
dony only ; others of chalcedony and jasper ; others, again, of
chalcedony and quartz, chalcedony quartz and jasper, and chal-
cedony, amethyst, and jasper. In order to understand the com-
position and formation of an agate, a clear definition of these
various forms is almost indispensable, although difficult to give.

Chalcedony may be defined as a crypto-crystalline form of
silica. According to Fuch and Dana, it is " Hydrated quartz, or
quartz with opal disseminated through it," and generally containing
a certain proportion of alumina. Bauerman says it "is essen-
tially a mixture of quartz and amorphous silica, forming botry-
oidal, reniform, or stalactitic masses, generally greyish or yellowish,
white, blue, rarely brown or red, and from translucent to nearly
opaque." It does not occur in definite crystals. It is readily
distinguished when it appears in a stalactitic form, but its principal
characteristic is its reniform structure, not only being kidney,
shaped, but showing under the microscope numerous incipient

132 THE ORIGIN AND HISTORY OF

acicular or needle-shaped crystals, radiating from a centre, and
giving to polished specimens a beautiful mammillated or mottled
appearance. Chalcedony has a waxy lustre, is semi-transparent to
translucent, and of various colours. The tendency to a reniform
structure is supposed to play an imjiortant part in forming the
circular and curved lines in agates. These are also affected by
the stalactitic process.

Quartz in agates is pure silica, crystalline, as in vein quartz,
and crystaUised, as in rock crystal, generally occupying the centre
of the cavity, but occasionally the outer rim and intermediate
zones. The strong tendency of quartz to crystallise in straight
lines and form true hexagonal prisms interferes with the circular
force exerted by chalcedony, and promotes the formation of irre-
gular figures in agates.

Jasper is a compact, amorphous, or non-crystalline, opaque
variety of quartz, having in some kinds a dull earthy, and in
others a conchoidal, or partially conchoidal, fracture. The opacity
is the result of alteration and the addition of oxides of iron and
other impurities. Some heliotropes or jasper bloodstones, being
chalcedonic varieties, are translucent at the edges. Many jaspers
are altered or metamorphosed sandstones, and porcelain jasper is
merely baked clay or shale, produced either by volcanic or plu-
tonic action, or by the burning of beds of coal in close proximity.
Ribbon jasper consists of parallel layers of various shades of red,
green, white, and yellow colours.

Egyptian Jasper occurs in nodules in the mud of the Nile and
in the sandy deposits in the district around Cairo. Central bands
divide the nodules into zones of various shades of brown colour,
the central zone being generally light brown, separated from other
lightish-brown zones by darker bands. These zones are supposed
to result from decomposition and subsequent colouring, in the
same way as zones in clay-ironstone nodules are produced. Prof.
Ruskin says jasper is eminently retractile, like the clay in septaria,
and in agates often breaks into warped fragments, dragging the
rest of the stone into distortions. In general, the embedded
fragments in any brecciated agate will be mainly of jasper, the
cement chalcedonic, or quartzose.

Opal — which is an occasional constituent of agate — is an

VARIETIES OF AGATE, ETC. 133

amorphous or non-crystalline form of hydrated silica, containing
water in varying proportions of from 5 to 12 per cent. It is
brittle and has a conchoidal fracture. Precious opal owes its
distinction to a rich iridescent play of colours. Common and
semi-opal are opaque or semi-translucent, white or yellowish brown,
and are not used in jewelry. Fire opal is red and brilliant, with
bright reflections.

Flint is a variety of silica allied to chalcedony, but distin-
guished from it by being more opaque and brittle, and by having
a more perfect conchoidal fracture ; also by being more capable of
forming sharp cutting edges, and is so hard as to scratch quartz.
Flint nodules are often found on the British coast, especially the
south coast, and the Isle of Wight, beautifully banded. They are
polished by lapidaries and sold as agates ; but are easily distin-
guished from true agates. Some red flints are passed as jaspers
and some as carnelians. Prof. Ruskin names flint as one of the
constituents of agate, but the apparent flinty portions of agate are
rather a variety of chalcedony than the flint of the chalk, though
chalcedony sometimes occurs in chalk.

We will now consider the mode of formation of agates. It
has been already stated that agates occupy cavities in varieties of
amygdaloidal trap rocks. Several problems difficult of solution
here present themselves : —

I. — How were the cavities produced?

2. — Whence the supply of silica of which the agates are
composed ?

3. — How the silica entered the cavities and became arranged
in bands, etc.

4.— How was the colouring effected ?

I. — As to the origin of the cavities.— The agate-bearing rocks
were originally, for the most part, molten lavas emitted from
ancient volcanoes. It is well known that volcanoes eject large
quantities of steam and gas. When these occur at the same time
as an eruption of lava, they fill it with steam or gas, as the case
may be. These bubbles rise to the surface and burst when the
lava is in an almost liquid condition. As it becomes more viscid,
the vapours or gases have less power, and as the rock or lava con-
solidates they escape or evaporate, leaving cavities such as may be

134 THE ORIGIN AND HISTORY OF

seen in loaves of bread that have been over-risen. These cavities
are subsequently filled with silica, sometimes in a crystallised, and
at other times a crystalline, an amorphous, or a colloid condition,
and resulting in the production of different mineral constituents.
That the cavities were thus formed is proved by the fact that they
are elongated generally in one direction — that is, in the direction
of the flow, instead of being globular or pear-shaped, with the
smaller end downwards, as indeed some are where the flow has
not been rapid. Some Continental writers who have been reluc-
tant to acknowledge the igneous origin of basalt and trap-rocks
have contended that the cavities have been pre-occupied by
crystals of calc-spar and other minerals, which on decomposition
have left vacuities which have afterwards been occupied by the
agates.

2. — The Source of the Silica. — One theory is that after the
rocks were consolidated, siliceous waters, supplied from deep-
seated sources, as in the case of geysers and other hot springs,
permeated them and gradually deposited silica in the cavities.

According to another theory, water containing carbonic acid
dissolved the felspar from the rocks and deposited the silica thus
set free in the cavities. And a third theory premises that also
from the rock itself silica was derived by a process of sublimation
produced by heat. Others have supposed that the mineral matter
has been conveyed by water from superincumbent rocks, as is the
case with the calc-spar in the Derbyshire Toadstone.

That the silica is derived from the strata which contains the
agates is pretty certain, for the more decomposed the traps are,
the richer, better, and more consolidated are the Agates.

3. — We must now consider the mode of entrance, deposition,
and arrangement of the various forms of silica in the cavity.
Some agates are cut so as to exhibit an apparent opening into the
cavity at one end, and sometimes in one or two other places. An
inspection of such a stone will show that the circumferential bands
do not meet at the smaller end, but run out on each side, forming
a botde-neck kind of channel. Through this channel or orifice it
has generally been supposed the silica- or agate-forming material
entered and spread itself by some unexplained method around the
sides of the cavities, in layers of different kinds and colours, as

VARIETIES OF AGATE, ETC. 135

successive supplies of silica arrived. This orifice has been called
the point of infiltration. If the silica did enter in solution in this
way, it is not easy to understand how it could arrange itself
around the walls of the cavity, and on the roof as well as on the
floor in layers of equal thickness. To overcome this difficulty,
Dr. Lange, of Idar, has suggested that after gelatinous silica, or
silica in solution, had been deposited on the floor of the cavity,
an accession of temperature caused the water to boil, and that the
pressure of the steam forced the jelly in all directions, and that
when the tension became too great it pierced an exit. Hence he
calls these apertures irruptive canals.

Another theory to account for the equal deposition of the layers
is that, as the saturated solution entered by the aperture, a current
would be produced between the solutions outside and inside to
establish an equilibrium, and the current sometimes passed out at
another aperture opposite, only partially coating the cavity, but
frequently rising above and passing round the roof and out at the
same opening by which it entered.

Dr. Rensch has tried to imitate the formation of an agate by
introducing into an irregularly formed cavity a thin cream of
plaster of Paris, shaking it round and pouring it out, when a layer
is left lining the walls of the hollow. This he repeated with
various coloured creams, forming successive layers until the cavity
was filled. A section of the nodule cut through presented the
appearance of a banded agate. He supposes that the cavities in
the amygdaloidal rocks were alternately filled and emptied by the
action of intermittent thermal springs.

In many agates a succession of varying bands continues to
near the centre, which frequently is filled up with compact silica,
chalcedony, or jasper ; but very often the centre is occupied by
quartz crystals. Sometimes the crystals meet and blend so as to
form a compact crystalline or semi-crystallised centre ; at other
times the crystals from each side just touch, showing a division
line between them. Sometimes they do not meet, but leave a
hollow studded with pyramidal crystals of quartz, rock crystal, or
amethyst ; these hollow nodules are called geodes. The shell is,
of course, a material of about a quarter of an inch thick, and
covered inwardly with globular concretions. These, again, are

136 THE ORIGIN AND HISTORY OF

Studded over with thousands of minute quartz crystals, and then
on these several dog-tooth calc-spar crystals have been deposited.

The theory that the various layers have been deposited by
silica in solution entering through an aperture has been objected
to, and another has been proposed and strongly advocated by Dr.
Haidenger in Germany and Prof. Heddle and others in England.
Their theory is that the silica enters the cavity in solution by a
general exudation through its walls in a colloid or gelatinous con-
dition, the first supply leaving a thin coating all round on the sides
and roof as well as on the floor ; while the centre of the cavity is
filled with water more or less pure. A fresh supply of a strong
solution, and by a process of dialysis, passes through the first or any
number of thin skins or layers, and as the layers increase forces
out the water through the channel which has been supposed to be
the point of entrance. An objection that some of the layers of
agate are impermeable and would not admit of the passage of the
silica through them, has been met by the fact that the microscope
shows that the concentric circles are crossed by radiating crystals
of tridamyte, through which the silica, and also various colouring
matters pass towards the centre of the cavity. But perhaps the
layers which now appear impermeable were not so originally.

Some agates are entirely filled up by concentric layers ; others
by concentric and horizontal layers ; and others, again, have, in
addition to these, a portion filled with compact chalcedony or with
quartz crystals. The concentric layers were evidently first pro-
duced by a slow process ; the horizontal layers may have been the
result of a more rapid accession of silica, or, as some scientists
think, by chemical precipitation on the floor of the cavity by the
introduction of an acid, as CO2, into the cavity. The remaining
portion, by an influx of silica, being filled in the one case with
chalcedony and in the other with quartz crystals formed by silica
held in solution, crystallising in the unfilled portion of the cavity.

The deposition of the successive layers of silica has not always
proceeded from the outside inwards ; frequently, it appears to have
proceeded from fixed centres by a radiating or stalactitic process.
The action of acids on gelatinous or colloid silica appears to have
the effect of producing slender tubes or [lipettes of consolidated
crystalline matter, and gradually depositing layer upon layer

VARIETIES OF AGATE, ETC. 137

outside the tube, until the cavity is filled or the growth stopped
by the cessation of the supply of silica. Sometimes the original
tube remains hollow, but generally it is filled up, leaving a dark
spot in the centre, with circles surrounding, showing the marks of
intermittent growth, as in the case of the eye agate and other
circular forms.

It has been suggested that some of the forms of fortification,
and other irregularly formed agates have been determined by
crystals of calc-spar having been formed in the cavities, and after-
wards dissolved, and their places filled up with colloid silica. But
in many fortification agates, the lines appear to follow the outline
of the cavity.

Professors Woodward, Raskin, and others suppose the lines
and markings of many agates procured from the drift are the
result of decomposition since the agates were set free from their
native matrix and embedded in the drift, as is known to be the
case with many banded and variously coloured flints.

Locality and Geological Position. — -The river Achate in Sicily
(how called the Drillo) is said by Theophrastus about 300 B.C.
(the earliest Greek writer on stones whose works are still extant)
to have given its name to the agate. The agate, he says, is an
elegant stone ; it has its name from the river Achate in Sicily, and
is sold at a great price. Pliny, in the first century of the Christian
era, informs us that the Achate was a stone formerly held in high
estimation, but in his day was of little or no value ; that it was
first found in Sicily, but has since been discovered in many other
places, including Cyprus, Phrygia, Egypt, and India.

Prof Forbes (in Oriental Memoirs) says the best agates are
found in peculiar strata thirty feet under the surface of the earth
in a small tract among the Rajpipla Hills, on the banks of the
Nerbudda. They are not met with in any other part of Guzerat,
and are generally cut and polished in Cambay.

Agates are now procured from various parts of the globe :
Africa, North and South America (especially Brazil), Australia,
Russia, China, India, Germany, and Scotland. They are found
plentifully in the Amygdaloidal trap-rocks of Scotland, notably at
Kinnoul hill in Perthshire, at Burne Anne near Galston in Ayr-
shire, near Montrose in Forfarshire, on the beach, in the sands, in

138 THE ORIGIN AND HISTORY OF

alluvium and boulder clay on the east and west coasts, both of
Scotland and England. These, as well as the extensive supply
now obtained from the gravels of the Uruguay and other rivers of
Brazil, have all been washed out of trap-rocks of one kind or
another.

The principal seat of the Agate industry in Europe is situated
in the valley of the Nahe, a tributary of the Rhine, which it joins
between the celebrated Mouse tower and Bingen. It is a fine
valley, bounded especially in its upper reaches by hills which rise
in ragged and grotesque crags, crowned with the relics of ancient
baronial castles. The river rises in the mountains which bound
the valley of the Moselle east of Treves and Saarbruck. The
Hunsdruck hills, ranging on the left bank of the Nahe, are com-
posed of Devonian Strata. The hills at the source of the river
are of volcanic origin, and have burst through the coal-field of
Saarbruck, and for some distance along the valley of the Nahe
are surrounded by permian rocks.

The volcanic rocks of the Galgenberg hills consist of the kind
of rock, called by Brougniart, melaphyre. "The uppermost bed,"
says Dr. Billing — to whom I am indebted for much information
on this part of the subject — " is a flinty conglomerate, composed
of water-worn gravel, of quartz, porphyritic or other trap stones,
worn into pebbles, and united by ferruginous earthy matter, and
much burnt by a stratum of trap-rock below it, which forced it out
of its level to an inclination of nearly 40 degrees." Underlying
this conglomerate is a dark brown amygdaloidal trap more or less
porphyritic, and passing into greenstone ; and again below this
lies another kind of trap rock, which constitutes the hill Galgen-
berg, near the town of Idar, which is the depository of chalcedony
and agates, which has rendered the district celebrated. Below
this is another stratum of trap, darker, denser, and more of the
nature of basalt in the lower bed than in the higher, which con-
tains the agates.

Agates formerly abounded in the alluvium at the foot of the
Galgenberg, and were readily collected ; and from very early
times workshops were established at Oberstein and Idar to grind,
cut, and polish them, There is documentary evidence that they
existed as early as 1454, and the industry was then an old one.

VARIETIES OF AGATE, ETC. 139

Early in the present century the supply of agates began to fail,
and could only be obtained by mining, and that with great diffi-
culty and expense. The mines are not now worked, as better
agates can be obtained at a cheaper rate from South America and
other places.

In 1827 two German agate-cutters, who had emigrated to
South America, observed that a courtyard at St. Leopoldo, in the
valley of the Uruguay, was paved with pebbles of agate, similar to
those they had been accustomed to work at Oberstein. They
collected a number of specimens from the drift in the bed of the
river Taquarie, and sent them to Oberstein, when, after being cut,
stained, and polished, they were pronounced to be of excellent
quality, and well adapted for general use, the carnelians being
especially good. Fresh supplies were sent for, and as they were
plentiful, large quantities were collected and sent over in ships as
ballast, at a trifling expense. This discovery gave a great impetus
to the agate industry, and the demand for agates increasing, the
landowners began to charge a royalty, the Governments of Brazil
and Uruguay put a tax on the exports, and the shipowners charged
for freightage. Consequently the cost of working was consider-
ably increased, but still there is a good demand for the stones, and
they constitute the principal source of supply for the agate indus-
tries of Europe.

Agates are collected in the valleys of the tributaries of the
Uruguay, and sent down to various ports on the coast in waggons
drawn by mules or oxen ; and are generally shipped to Hamburgh,
Antwerp, or Havre, from Buenos-Ayres or Monte-Video ; and
ultimately to Oberstein, where they are sorted and sold by auction
in open market, or in the courtyard of one or other of the Inns.
This industry is carried on chiefly in the villages of Oberstein,
Idar, and Birkenfeld, and in numerous neighbouring hamlets in
the valley of the Nahe, and its various small tributaries which
supply the water to turn the numerous small mills at which the
agates are ground, cut, and polished. The little river or brook
Idarbach flows through Idar at the height of 1,012 feet above sea
level and Oberstein, near which it joins the Nahe at 905 feet.
The majority of the agate mills are situated in the valley between
the two towns, which are about two miles distant from one another.

140 THE ORIGIN AND HISTORY OF

The red sandstone of the Zweibruken furnishes grindstones
usually from five to six feet in diameter, with which the agates are
ground down ; the stronger and coarser agates are chipped into
shape with the hammer, and then ground, the finer ones are cut
with circular steel plates with plain discs, covered with oil and
emery powder, and for finer work diamond dust ; and polished
on rotating wood or lead cylinders, moistened with tripoli. The
labour of grinding is severe. " The workman," says Professor
Rudler, "lies upon alow wooden grinding stool, specially con-
structed to fit to the chest and abdomen, leaving the limbs free.
The hands are engaged in holding and guiding the agate, whilst
the feet are firmly pressed against short stakes or blocks of wood
screwed into the floor ; the reaction enabling the grinder to press
the agate with much force against the moving millstone. The
millstones rotate at the rate of 180 revolutions per minute, and
the friction is sufficient to rasp down the hardest stones. About
180 mills, with 850 grindstones, are kept constantly employed. A
number of workmen are employed in cutting cameos and intagli
in carnelian or sard and onyx.

The artificial colouring of stones forms a separate branch of
the agate industry. The art of colouring stones artificially was
known to the ancients and preserved by the Italian cameo
lapidaries in Rome, but kept as a secret, and was unknown in
Germany until about 1819, when a German lapidary and a Roman
stone engraver were imprisoned in the same cell in Paris, and
during conversation the Italian let out the secret, which was soon
made known and practised in Oberstein, when common grey
chalcedonies of no value were stained and transformed to good
onyx, thus giving an impetus to the industry.

The porous bands of the agate may be stained almost any
colour by artificial means, while the finer and harder bands, being
impervious, are unaffected. One method is to wash the stones
and dry them thoroughly, then steep them in oil and honey or
some other saccharine substance and water, and after a few days
expose them to a moderate heat; then after washing, to place
them in sulphuric acid, and again expose them to a gentle
heat. The oily and saccharine matter, being absorbed by
the porous portions of the stone, is acted upon and decom_

VARIETIES OF AGATE, ETC. 141

posed by the sulphuric acid, and a deposit of carbon pro-
duced. Colourless banded agates are in this manner changed
into onyx with black or dark brown and white layers. The bluish-
white chalcedonies are changed in the process by heat to almost
pure white ; and perhaps the contrast of colour causes the white
bands to appear whiter than they really are.

The sard or red tint is produced by soaking colourless or grey
chalcedony in a solution consisting of nitric acid, water, and iron,
and then heating it. Blue, green, and yellow tints are also pro-
duced by chemical means, the colour depending upon the salt in
which it is boiled and the re-agent used to precipitate the colour
required. Deep colours can be reduced by the action of nitric acid.

The principal colouring matters in agates, as found in nature,
are various oxides of iron and manganese, and probably chrome.
Polished stones, agate, onyx, sardonyx, etc., are made into orna-
mental articles of various kinds by German, French, Italian, and
other lapidaries, as brooches, bracelets, beads, seals, snuff-boxes,
small vases, paper-knives, handles for knives and forks, etc. The
common agates are used in leather dressing, paint-pounding, etc.,
and for mortars for chemists to pound their drugs in.

In Eastern countries they are used for inlaying in marble
pillars, cornices, and other portions of palatial buildings. Mr.
Forbes, in his Oriental Memoirs, says : — " I was delighted with
the mausoleums of Botwab, though they are inferior to those at
Agra and Delhi, where imperial wealth and magnificence had
united to decorate the tombs of the Mogul princes and their
favourite sultanas, the ornamental parts being entirely composed
of agates, carnelians, turquoises, lapis-lazuli, and other valuable
gems."'

On the restoration of Crathie Church — where the Queen and
Royal Family occasionally attend during their residence at Bal-
moral—a polished granite pulpit was erected during the present
year (1895), which is inlaid with agate pebbles collected on the
shore in the island of lona by Princess Louise, Marchioness of

Lome.

Agate Superstitions.

Camillous Leonardus, M.D., 1502, says :— " It subdues the
poison of vipers, and scorpions if bound on the puncture, or

142 FORMATION OF CHLOROPHYLL AND STARCH.

being bruised and drank in a glass of wine. Indian agate refreshes
the sight by looking on it. Being held in the mouth, it quenches
thirst. It gives victory to him that wears it ; turns away storms,
and puts a stop to lightnings.

Cretan agate renders the wearer of it gracious and eloquent.
Preserves and confirms strength, and produces good colour or
complexion."

Thomas Nichols, author of The Lapidary, or The History of
Precious Stones, 1652, says: — " It is reported of the eagle that it
doth carry this gemme (agate) into her nest to secure her young
from the bitings of venomous creatures."

Robert Lowell, 1661, says: — "Agates of one colour causeth
audacity. Being hung about the neck, it maketh prudent and
eloquent, and preserves from danger."

Formation of Chlorophyll and Starch. — A very extended
series of observations on the mode of formation of starch grains
and chlorophyll bodies in plants has led M. E. Belzung to the
following general conclusions : — The first process which takes place
in the embryo is the formation of starch, the result of the activity
of the protoplasm of the young embryo. The substratum of the
future chlorophyll body — leucite or plastid — is always fully formed
by the time the seed arrives at maturity ; the protoplasm has
always a reticulate structure ; it is the protoplasm of the amylifer-
ous vacuoles which constitute the chromatophore or leucite. Those
starch-grains which are destined to constitute the reserve food
material in the ripe seed are an exception to the rule, and increase
as the embryo becomes green and the mass of green corpuscles
more abundant, the starch grains are resorbed ; they form a part
of the material for building up the green chlorophyll grains. In
adult green organs, especially leaves, the starch-grains, which are
formed in the light in the chlorophyll bodies, are the result of the
assimilating power of these latter, being one of the products of
the substance itself of the chlorophyll bodies, a kind of secretion
from the green substance. The resorption of the chlorophyll —
which in leaves takes place only at the period of the autumnal
fall — is, on fruits, effected almost entirely before they ripen. The
two essential phases in the life of a plant — the embryonal phase,
during which the green cell is built up at the expense of materials
which it has not elaborated ; and the adult phase, in which its
formative activity is manifested by new embryonal conditions —
constitute a remarkable example of organic reversibility. — Morot's
Journal de Botanique in the Pharni.Journ.

[ 143 ]

Britisb 1b^^racbni^a^♦

By Chas. D. Soar. Part IV. Plate VI.

THE next genus we will consider is Nes/EA. This is another
large genus, and when worked out will number as many
species as Arrenunts, if not more. Koch, in his Deutsch-
lands Crust., etc., describes and figures thirty-four species ; some
of these have since been removed to other genera. Koch himself,
in his Ubersicht, reduced the number to twenty-eight, making a
new genus for some, which he named Piona. We will notice
this genus later on.

Several species of Nesaa are very common in England, some
being very small, almost as small as Axona versicolor, others are
as large as some species of Hydrachna. They also show a great
diversity of colour, greens, browns, yellows, and reds of all shades,
being represented by these little mites, one of the most beautiful
htvixg Nes(Ea coccinea (Y^O(ik\). As they are soft skinned,! have
not been able to mount any of them in Balsam successfully. The
integument always collapses in mounting, and the slides are thus
rendered useless. The best medium I have yet found in which
to mount Nescea is a 5 per cent, solution of formalin (this is a
formula given me by Mr. Rousselet). It unfortunately removes
the colour from the mite in the majority of cases (although not
always), but it preserves the shape and structure beautifully ; in
fact, the ventral side is often more distinct when mounted in the
medium than it is in life ; of course, if a coloured drawing has
been made from the life, it does not very much matter if the
colour of the mite is removed. The mount will show all the struc-
ture, but as a beautiful object for the microscope it is spoilt.

Before we know very much about fresh water mites, the life
history of some will have to be worked out. The metamorphosis
from the egg to the imago will have to be carefully watched and
studied. For this we want a naturalist with the time, perseverance,
and ingenuity of Mr. Michael, who will do for the Hydrachnidcz
what he has done so thoroughly for the British Oribatidce ; in two
or three cases I know it has been done, as, e.g., A tax ypsilophora
by Van Beneden, in 1848 ; Atax Bonzi by Claparede, in 1868 ;

144 BRITISH HYDRACHNID^.

and Arrenurus papillaior, and others, by Max Krendowski, the
Russion Naturalist, in 1878. This will be found to be no easy
matter, for I have no doubt the larva of Nescea becomes parasitic
at a very early stage. The query is, on what does it become para-
sitic ? If the reader interested in this will turn to page 99 of
Science Gossip for 1870, an outline drawing will be found called
the Parasite of the Sand-fly, by W. Hanwell. If this drawing is
compared with my outline drawing from the life of the larva of
NescEU carnea, Fig. 3, g, I think the conclusion arrived at will be
that Mr. Hanwell's drawing represents also a larval form of an
Hydrachnid.

We know by Krendowski's book that the larv^ of Arrenurus
papillator spend some part of their time out of water, because he
figures them on the wings of a Dragon-fly, These remarks will
show some of the difficulties to be encountered. Accident or
chance will, perhaps, reveal facts which have not been previously
noticed ; the great thing, I think, is first to become well acquain-
ted with the larval forms, and then to search every living form,
whether found in the water or out of it, that is likely to become a
host for these little creatures. Of course, I am now referring to
Nescea only.

The Oribatidcs, which were so well worked out by Mr. Michael,
are not parasitic at all at any part of their life. By finding out
what the creatures fed on, keeping the cells moist, and the expen-
diture of a lot of patience and watchfulness, he was able success-
fully to trace their life-history from the egg to the perfect mite ; but
with the Hydrachnidce it is different, I have traced several differ-
ent species from the egg to the larva, and there I come to a full
stop. My friend Dr. George, of Kirton-Lindsey, has also reached
the same point with several mites, but like me has not, at present,
succeeded in going further, except in the case of an undetermined
species of Hydrachna which was found parasitic on Dytiscus
niarginalis.

The metamorphoses of Nescea consist of four stages : first,
the egg, but I am not quite certain that all water mites deposit
eggs ; some genera may prove to be ovoviviparous, but it is certain
that the members of the genus Nescea do deposit eggs ; in con-
finement they lay them on the stalks and leaves of the water

BRITISH HYDRACHNID^. 145

plants, and on the sides of the glass tank, a batch of eggs at one
time in a gelatinous film. Second we have the larval form, see
Fig- 3> gj which is very unlike the adulr, and is hexapod. Thirdly,
we have the nymph. I have taken several of what I believe to be
Nescea in this stage ; they have eight legs, but only two pores in
a special plate, on each side of the genital fissure, but with my
present limited knowledge I should not like to say to what species
of Nes(ea these different nymphs belonged. How long a time they
exist in their various stages, and how many times they change their
skin during these periods, are questions yet to be answered.
Fourthy, the imago or perfect mite.

It will, perhaps, be interesting to give particulars of the develop-
ment from the egg to the larval stage of Nescea carnea, so far as
my own observations have gone.

The Quekett Club during the summer months have an excur-
sion every fourteen days to interesting collecting grounds round
London, which is a great boon to members who live in London,
and are engaged in business all the week. On May i8th, 1895,
the excursion was to Staines. On Staines Common there are a
number of small ponds, and from these ponds I took a number of
water mites, which I believe to be Nescea carnea (Koch). This
mite is rather large, and of a deep maroon colour, long oval in
shape, and the eyes stand out on two prominent swellings, which
seems almost colourless compared to the rest of the body (I was
not fortunate enough to take a male N. carnea).

On reaching home, I separated all the Nesaa carnea from
other mites which I had collected, and put them into one small
glass tank which stands on my window-sill, and next morning I
found that a quantity of eggs had been laid on the water plants
and the sides of the tank. I then took out three or four mites
with a dipper, and put them into a small trough, and on the
morning of the 20th I had the satisfaction of finding a batch of
eggs laid in a most convenient position for microscopical examina-
tion. I again removed the mites and put the trough in position
under the microscope, and examined the eggs at every opportu-
nity. At first, they had the appearance of Fig. 3, orange red in
colour, and embedded in a film of gelatinous matter, of a pale

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. k

146 BRITISH HYDRACHNID^.

yellow colour. This film was covered — or at least appeared to be
so — with little cracks ; it was firmly attached to the glass. Fig. 3, a,
shows the appearance of two eggs under a higher power. There
were sixteen eggs in this one group. Each egg seemed to have its
own share of film, although all were in one mass. The eggs gra-
dually altered from circles to ovals, until on May the 24th they
had the appearance of Fig. 3, b. It will here be noticed that the
red portion of the little egg had begun to contract at each end.
On May 28th they had the appearance of Fig. 3, c. On May 30th
the eyes in some cases could be seen quite plainly (Fig, 3, d).
On May 31st the shape of the little creature could be distinctly
made out (Fig. 3, ^) ; a constant movement of the limbs could be
plainly seen. The delicate membrane in which the eggs were laid
was also cracked all over in a very marked manner, no doubt for
the purpose of letting the little creatures escape. On the morning
of June the ist, when I examined them, some three or four of the
larvae had escaped and were swimming freely about. When I
looked again in the evening, all were out swimming vigorously.

Fig. 3, g, is drawn from the ventral side of one of the larvse
three days after it was hatched. How long they live in this form
I cannot say. I placed all when hatched in a small tank with
nothing but vegetable life, and found them alive on June the 20th.
The larva is a pale yellow colour, with a bright red, double cres-
cent-shaped patch on the body, as shown in Fig. 3, / the shaded
portions representing the red colour. This is as far as my own
observations at present have gone with the larva of Nescea.

Genus IV. — Nes^a (Koch).

1842. — C. L. Koch, Ubersichi des Arachnidensy steins, No. 3, p. 10.

Body, soft skinned ; legs well supplied with swimming hairs ;
claws to all tarsi. The tarsi and ungues of the male, and the third
and fourth pairs of legs specially modified. On each side of the
sexual fissure are six or more so-called genital pores, either sunk
into the skin or on special plates. The epunera form two separate
groups on each side. Palpi not chelate ; mandibles in two dis-
tinct portions ; eyes wide apart.

----^TTT^- Journal of Microscopy, S^-^ Sen Vol. 6, Plate 6.

Chas. D. Soar czd not. ae.. ,1/ ' /"

BRITISH HYDRA CHNID.?*:. 147

Nes^a Longicornis.

1834 — 41. — Nescea longicornis, C. L. Koch, Deidschlands Crust.,

etc., p. 9, Figs. 14 and 15.

Koch gives, in his Ubersicht, Nescea rosea as his type of Nescea
(see Fab. I., Figs. 2 and 3). I have described and illustrated
Nescea longicornis because I happen to have a male and female of
the same species. I have found several males of Nescea, but am
at present uncertain with which females to pair them off. Mliller
also figures longicornis on Twb. IV.. Fig. 4, and describes it on
page 47. Newman also gives N. longicornis, but I am not certain
if it can be the same as the one described by Koch. N. longicor-
nis is pale yellow in colour, with dark brown patches on the dorsal
side, and a red Y-shaped mark in the centre, extending from just
behind the eyes to the posterior margin ; in Koch's figure this
mark is very plainly shown.

The first three joints of the legs, counting from the body, are
pale yellow, which gradually turn to a pale blue on the last three
joints, those of the male and female being the same in this
respect. The body of the female is oval in shape. The legs are
very much alike. The epimera (see Fig. 2) are wide apart. The
body of the male is flattened on each side and bent inwards on
the anterior margin. The epimera of the third and fourth pairs
of legs are close together ; they very nearly, but do not quite
touch (see Fig. i, a). Close to the posterior margin of the
epimera is the genital fissure ; the third pair of ungues of the
males are more often than not firmly hooked into this part. I
have endeavoured to show this on one side of Fig. i, a. The
fourth leg is very peculiar (see Fig. i, d). The length of the body
of the female is 1 3/1 50th of an inch, that of the male being
i9/3ooth,

EXPLANATION OF PLATE VI.

Fig. 1. — Dorsal view of Nescea longicornis, male.

,, 1, a. — Ventral view of same, showing on one side the way the
third pair of feet are held in the genital opening.

,, 1, b. — Genital area of male.

,, 1, c. — Third leg of ,,

148 BRITISH HYDRACHNIDiE.

Fig. 1, d. — Fourth leg of male.
1, e. — Palpus of ,,

2, — Ventral view of Nescea longicornis, female.
3. — Eggs of Nescea carnea, as deposited on side of glass.

3a, ■v

36,

3c, I Showing progress of development of the egg.

3d,

3e, I

3, f. — Dorsal side of larva at time of hatching.

3, g. — Larva, ventral view, three days old.

The Burning Tree of Burmah. — There has lately been
added to the collection of plants at the Botanic Garden, Madras,
a tree bearing on the underside of its leaves stings which leave no
outward sign when they pierce the skin, though the sensation of
pain persists sometimes for months, and is especially keen on
damp days or when the place which has been wounded is plunged
into water. The natives in the parts of Burmah where the tree
grows are said to be in such terror of it that they fly in haste when
they perceive the peculiar odour which it exhales, and if they
happen to touch the tree they fall on the ground and roll over and
over on the earth, shrieking meanwhile. Dogs and horses touched
by it run wildly about, biting and tearing the parts of their bodies
that have been touched. — Pharm. JourtiaL

Distribution of Seeds by the Wind. — BoUey {Pop. Science
News) records some interesting facts on the distribution of seeds
by the wind. In two square feet of a three-week-old and three-
inch-deep snow-drift, on the ice of a pond ten yards from any
weeds, he found nineteen weed seeds, and, in another drift, simi-
larly situated, thirty-two seeds representing nine distinct species.
While the wind was blowing twenty miles an hour, he poured out
a peck of seeds upon the snow-crust, and ten minutes after one
hundred and ninety-one wheat grains, fifty-six flax seeds, forty-
three buck-wheat seeds, and ninety-one (American) rag-weed seeds
were found in a trench thirty rods distant from where they had
been poured out. — Pharm. Journ.

[ 149 ]

Ximna:a pereara*

By William Nelson.*

LIMN^A PEREGRA — or, as it has been variously named,
The wide-mouthed Helix, The Mud Snail, The Traveller,
The Wanderer, The Wandering Mud Snail, etc. — is pos-
sessed of a rather long history. The first notice of it that I have
seen is by Martin Lister, published in 1678. It has since then
been described by a great number of writers, and has become
possessed of a long string of names or synonyms, of which I have
collected upwards of two hundred. These are in addition to the
generic and sub-generic synonyms, and as the process is still
going on there is no fixing the limits of its titles. The chief
offenders in this respect are the French conchologists. The
Germans are bad enough, though not nearly so culpable as the
Bourguignat school. We ourselves are not without blame in this
particular, as with some of our recognised authorities the chief
requisite to command a new specific name seems only to be that
it shall be found in a part of the world which has not previously
been well explored ; for it is no doubt much easier to sit down
and describe under a new name than to laboriously overhaul what
has already been written, and refer the form to its proper place in
the genus to which it may belong. Another reason for the
enormous mass of synonyms which has gathered round this
species is, no doubt, the great variation in size, colour, shape, and
texture, which again is accounted for by its excessively wide dis-
tribution and the great differences in its environment.

Passing over its ordinal and generic characters and coming to
the species, the animal may be described as having the tentacles
triangular, flat ; the foot broad, obtusely rounded, and broader in
front, and gradually narrowing, and somewhat pointed behind, and
the underside of the foot grey.

The body varies greatly in colour and has been described by
different observers as being dark-grey, brown, greenish brown,
olive-yellow, or yellowish grey, often mottled with small ring-like

*Read before the Leeds Branch of the Conchological Society, Oct. 10, 1895.

150 LIMN^A PEREGRA.

markings of a lighter colour, which are readily seen through the
shell in the thinner varieties.

The eyes are at the inner base of the tentacles.
In attempting to describe the shell we are confronted with a
somewhat difficult task, the variations being so great that it is only
by fixing upon a certain form as the type that this can be accom-
plished. We, therefore, take the elongated form as our idea of
the type, and accept Dr. Jeffreys' description so far as it agrees
with our own examination.

Shell obliquely ovate, thin,
moderately glossy, semi-transpa-
rent, yellowish-horn colour, irregu-
larly striate by the lines of growth,
epidermis thin, whorls four to
Fig. \.—L. peregra. five, convex, the last occupying

three-fourths of the shell ; spire produced and pointed, suture
rather deep ; mouth large, oval ; outer lip thin (he says), slightly
reflected (which scarcely agrees with my experience) ; inner lip
folded on the columella, forming behind it a slight umbilical cleft;
fold rather prominent and curved. Length three-quarters of an
inch ; breadth rather less than half-an-inch. Shell dextral. Dr.
Jeffreys mentions some specimens from Ireland, which exceeded
an inch and a quarter in length.

Reeve says there is no fear of mistaking the most widely
inflated forms of Limncea peregra for Z. auricularia, but I am not
quite sure of this, having personally known instances where this
mistake has been made, even in the latest published work on the
MoUusca.

Limncea auricularia has been figured as
L. peregra. The long, narrow form — var.
elongatissima — has also been mistaken for
LirnncBa palustris, and these mistakes made,

too, by conchologists of ability. For a con-
Fig. 2. -var. e^;^ra/^55^wa. ., , , . . , ,

siderable tune it has been customary to

range Z. peregra next to Z. involuta ; but of late opinion seems to

be trending in the direction of suppressing the latter form as a

species, and regarding it as a local variety of an extreme form of

L. peregra. Even Dr. Gray, who was, as all will admit, a most

LIMNiEA PEREGRA. 151

painstaking naturalist, refers the Litnneus aciitus of Jeffreys to
Limnceus peregra var., whilst I think that most conchologists would
agree with Dr. Jeffreys, and refer it, as he did later, to L. auri-
cularia.

Von Maltzan unites L. peregra with L. aiiricularia. It cer-
tainly comes very near to L. lagotis, some of the numerous
varieties of which can scarcely be separated from Z. peregra.

Litnncea peregra has been found in a fossil state in the Mam-
malian Crag at Southwold and at Bramerton, also at Stutton and
at Clacton. It is often found in a sub-fossil state, as at Askern,
and in the banks of the Tutt at Staveley. Mr. Roebuck found
fossil specimens in the mud cliffs at Hornsea, whilst myriads of
this species are turned up by the drainers at Silverdale.

[n a living state it occurs in rivers, streams, ditches, ponds,
and lakes, at all elevations, from mountain tarns down to the
brackish water on the sea beach, being found in ponds within
reach of the spray from the sea-waves. A variety of it was collect-
ed by Dr. Hooker on the Thibetian Himalaya, at an elevation of
18,000 feet.

It is very generally distributed over the whole of the British
Isles, throughout Europe, Afghanistan, Siberia, and throughout
North America, under the name of L. colmnella and many other
synonyms. It has also been found in Tasmania and described by
Rev. E. Tenison Woods as Limncea hobartonensis, L. huonensis,
L. launcestoniensis , and lastly, a few years ago Dr. Edward Atkin-
son kindly presented me with a few freshwater shells, sent to him
direct from a place called Tsing-fu-chu in North China, amongst
which I was pleased to find our old acquaintance, L. peregra.

In some cases it is very difficult to account for the local dis-
tribution, seeing that it is almost invariably the first species to
make its appearance in a new pond, as, for example, brick ponds,
in situations where no flood water can reach, and near large towns,
which are not likely to be visited by aquatic birds bringing a
supply of young fry attached to their feet.

A few curious cases have been recorded of how they might
become distributed. Mr. W. Thompson, in 1841, mentioned that
he once saw a number of L. peregra attached to the backs of
some turtles kept in a pond at Fort William near Belfast, and they

152 LIMN^A PEREGRA.

appear to have held on with some firmness, for the turtles were
swimming about with the LimncEce still keeping their seat upon
them. But still more curious is the case recorded by Mr. Standey,
who states that in 1883 he saw a full-grown specimen oi L. peregra
upon the back of a toad, which was tramping leisurely along the
road in the dusk of the evening in the vicinity of Goosnargh, near
Preston, about twenty yards from the water of a roadside pond.

It is said to breed in August, but this, I think, must be a
mistake, as my own experience has always been that they have
deposited their spawn in March, April, and May. We are told
that one individual deposits upwards of a thousand eggs. The
eggs are round, colourless, or pellucid, with a whitish, opaque spot
at one end. They generally number from forty to eighty or more
in one mass, and are enclosed in narrow, cylindrical shaped masses
of gelatinous or protoplasmic substance. The opaque spot
becomes larger from day to day, and for several days before it
leaves the mass it may be seen moving backwards and forwards.

Most of the full-grown animals which deposit their eggs in
early summer at once die off, resembling in this particular many
other of the lower order of animals, which seem to have attained
their purpose when they have perpetuated their kind.

M. Bouchard-Chantereaux says that the eggs hatch in from
fifteen to sixteen days, but no doubt in this, as in other species,
the length of time will depend in a great measure upon the tem-
perature. Mr. E. J. Lowe, in his excellent little work on The
Conchology of Nottingham^ says that it breeds in August ; whilst
the late Mr. Charles Ashford, with his usual accuracy, says : " Fry
innumerable during May ; no adults to be found after June."
This T believe to be the experience of all outdoor naturalists. It
is gregarious and rather active, being fond of floating on the
surface of the water with the shell hanging down. It shares with
its congener, L. trtincatula, the habit of leaving the water and
making peregrinations on the damp mud, sometimes to some dis-
tance from the water.

Although, as a rule, animals of this species are vegetable
feeders, they have often been rightly charged with destroying fish
in aquaria. There is also no doubt that they often eat the bodies

LIMNyEA PEREGRA. 153

of their dead brethren. Clessin observes that it attacks the
shells of its fellows only if vegetable food is wanting.

Mr. Jones states that he had frequently given L. stagnalis and
Z. limosa (another name for Z. peregrd) dead bleak and other
small fish, which they have reduced to a skeleton in a very short
time, although abundance of vegetable food was at hand. Dr.
Gray says that in the spring these animals are often infested with
a small, slender species of Gordius, which afifix themselves to the
edge of the mantle over the back of the neck. These parasitic
worms are so common that Draparnaud mistook them for the
respiratory organs of the animal. They are also preyed upon by
leeches and fishes as well as aquatic birds. In fact, ducks are so
particularly fond of molluscs, that where they are kept it is almost
useless to search for shells.

Mr. J. W. Williams records having kept a number of Dytisci
which he fed upon Z. stagnalis and Z. peregra. The beetles,
though eating both species, evidently showed a preference for
Z. stagnalis.

Though a hardy species, Z. peregra hibernates for a short time
during winter, but for a rather longer period than Z. stagnalis. The
Rev. W. C. Hey records its behaviour under somewhat peculiar cir-
cumstances. The Ouse at York was considerably lowered by
opening Naburn Lock, exposing a number of fresh-water shells on
the muddy banks. The same night a keen frost set in, the mud
becoming perfectly hard to the water's edge. The Z. peregra.,
however, burrowed itself a hole in the mud, apparently by a rota-
tory movement of the shell, and lay there warm and damp. He
says : — " I opened several of these holes, and do not think a
single specimen died."

That it burrows in the mud to escape the cold I readily admit.
At the same time, it does not seem to possess the knowledge how
to escape the effects of heat as successfully as Mr. Hey credits it
with regard to the frost, for we often find hundreds dead at the
bottom of dried-up ponds in summer. But some allowance
should be made here, for they may perhaps have deposited their
ova and so completed their life purpose. But so long as there is
sufficient moisture it can survive a very high temperature. In
some of the mill-cisterns at Cheadle, Staffordshire, into which the

154 LIMNJi:A PEREGRA.

warm water is discharged, and which water during the day is con-
stantly rising in temperature, the mollusc crawls out of the water
when it reaches 120 degrees Fahrenheit. It has then stood as
much of the heat as it is able. It, however, returns to the water
again during the night, when the temperature is lower.

This species varies very much ; in fact, there is no particular
in which there is not great variation. The shell may be very thin,
as in var. thermalis, or very thick, as in var. lutea ; the spire may

^lJ^

Fig. 3. — var. therinalis. Fig. 4. — var. burnetii. Fig. 5. — var. viarginata.

Fig. 6. — var. labiosa. Fig. 7. — var. obiusa. Fig. 8. — var. obloiiga.

be produced, as in var. elongaHssitna, or even intorted, as in var.
burnetii; it may be dark brown or pure white, the lip may be
simple, as in the type, or it may be thickened, as in var. margiti-
ahi, or reflected, as in var. labiosa; the front margin of the shell
may be inflated and rounded, as in var. obtusa, or it may be com-
pressed and flattened, as in var. oblonga. A good deal of ingenuity
has been exercised by our ablest naturalists to account for the
divergence between the long form, which is generally accepted as
the type, and the globular or ovate forms, it being generally
accepted that the long, narrow forms inhabit streams where less
resistance is offered to the running water than would be the case
by the globular forms ; hence the latter inhabit ponds where there
is no motion in the water. Most of the Continental conchologists
regard var. ovata as a distinct species ; but Hazay looks upon

Fig. 9. — var. ovata.

LIMN^A PEREGRA. 155

Z. peregra only as a biological
variety of Limncea ovata, pro-
duced by living in hard running
water, and mentions cases in
which eggs of ovata were trans-
ferred into springs or rivulets,
and the animals hatched from
them were L. peregra, and also
vice versa. This, if correct, is,
of course, very interesting. It certainly does not agree with my
own out-of-door experience, some of the most elongated forms in
my collection having been obtained from ponds.

Warm water produces thin shells, as vz^.thermalis ; absence of
lime a decollated shell ; an interesting account of which, by Mr.
Crowther, will be found in the Naturalist for 1879. Brackish
water is said to be productive of stunted L. peregra, but of this I
am very doubtful. There have as yet been no experiments made
of which I have seen any record with L. peregra of such com-
pleteness and so full of interest as those made with L stagnalis
by Carl Semper, and until this has been done there will be many
random guesses as to the cause of variation in this species.

For a long period three or four varieties were all that were
recognised by British authors ; then Dr. Jeffreys' work extended
them to eleven, but since Darwin's work on the Origin of Species
was written, the impetus given to specialisation has been so great
that most small points which were then overlooked are now noted,
so that a great many more named varieties will be required. But
this extension should be made with great caution, otherwise the
differences will be so slight that even the authors themselves will
have no little difficulty in recognising their own work.

Then, last, we have to consider the abnormal shells, some of
which are most strange in shape, some, no doubt, produced by
injuries to the mantle, some sinistrally formed, some swollen out
in part of their growth when food has no doubt been in abund-
ance, then narrowing down again when harder times have come
upon them ; others are scalariform, perhaps caused by some
obstruction to the shell-producing mantle continuing its work on
the same plane of convolution. Many of the abnormal forms are

156 GERMINATION OF OILY SEEDS.

produced by transitory causes, the shells next season resuming
their normal form. An interesting and instructive collection might
be made from a single pond, continued over a series of years.
This has been done, to a small extent, by our friend, Mr. Madison,
and serves to show that slight alterations in the environment, so
slight as to be imperceptible to the conchologist, still leave their
impress upon the shells.

Mr. Purves describes and figures a specimen obtained by him
on Belford Moor, Northumberland, which had a regular keel
round the upper part of the whorl, giving the shell an appearance
very unlike the normal form of the species, This was, no doubt,
due to an injury to the mantle of the animal.

Dr. Brot mentions that in a pond in the environs of Geneva a
number of abnormal forms of this species were obtained. The
pond swarmed with Hydra viridis, which he fixed upon as the

cause of the variation, being confirmed in
this opinion by the disappearance simultane-
ously of the Hydra and the abnormally
formed shells.

During March, 1883, I collected many
specimens in a pond at Allerton Ings, the
Fig. 10. -Abnormal Shell, majority of them being deformed, the cause
of which I ascribed at the time to superabundance of food.

The Germination of Oily Seeds. — According to M. Leclerc
du Sablon, the reserve substance of oily seeds, whether they are
stored up in the embryo or in the endosperm, consists chiefly of oil
and aleurone ; starch is but rarely found in them. In the species
examined, the proportion of oil decreases regularly during the period
of germination. By the action of a diastase, the oil is transformed
into fatty acids without any separation of glycerin. During germi-
nation these fatty acids, instead of accumulating, are themselves
transformed into carbo-hydrates, especially into those belonging to
the group of saccharoses. This saccharose is again converted, by
the action of a diastase, into glucose, which is directly assimilated
by the plant. Starch is also temporarily present as an intermediate
product between oil and glucose. Starch and oil, as reserve sub-
stances, give rise to the same assimilable products during the ger-
mination of the seed. — Bonnier's Revue Generale de Botanique.

[ 157 ]

lI^rc^aciou0 d Iparaeitic lenemiea of Bpbibee

(incluMuG a Stu&^ of HDi^per^patasttes).

By H. C. A. Vine.
Part IV. Plates VII. and VIII.

THE Linnsean order, Hemiptera, to which the Aphides them-
selves belong, includes some species which are actively
aphidivorous in all stages of their existence.

Like certain genera of the Neuroptera, this order is distin-
guished by the ' incomplete ' character of the metamorphosis
which the various species undergo, the adult differing from the
larva form generally only in the possession of wings and in minor
structural details, which are, however, of a nature to make the
resemblance often difficult for an inexperienced eye to trace,
especially in such genera as Phyllaphis, Phylloxera^ Calocoris, and
Caps2is. The habits of the larva and the nature of its food are
generally the same as that of the imago, and the acquisition of
wings rarely involves any change in environment except such as is
due to an alternation of hosts. These circumstances, together with
the coriaceous nature of the anterior pair of wings, led Linnaeus to
unite these insects in a single order with the Orthoptera.

The totally different structure of the mouth parts rendered
some further division necessary, and Latreille at a later date
effected the separation of the incongruous groups, the distinguish-
ing character of the Hemiptera since his time being the prolonga-
tion of the mouth into a fleshy rostrum, or beak, supporting four
setae, which are considered to be the homologues of the mandibles
and maxillae in other insects. The possession of this suctorial
apparatus has led some naturalists to adopt the designation of
Rhynchota, or * beaked insects,' for the group in preference to
the older term, Hemiptera. Similarly to the Neuroptera, the
Hemiptera have been sub-divided into two great sections on the
basis of their characteristic wing-structure. The best-known of
these sub-orders (the Hemiptera- Homoptera) includes the Aphides,
Cicadas, Thrips, Coccidae, and other less-known groups, and its

158 PREDACIOUS AND PARASITIC

distinguishing character is the possession by the imagines of four
membranous wings.

The remainder of the order, designated Hemiptera-Hete/vp-
tera, bears in its name a reference to the partially coriaceous
nature of the anterior wings, which, whilst serving, as in the
Coleoptera^ as a cover for the membranous pair beneath, are each
furnished with an asymetrical membranous extension, which
enables them to be used as efifeclive instruments of flight. The
species of this sub-order are popularly known as ' bugs,' and
whether or no the unsavoury association of ideas thus engendered
has had its effect upon the studies of naturalists, certain it is
that the group, as a whole, has had but little attention devoted to
it in comparison with the Diptera, or even with the other section
of the same order. Probably, the ' water boatman,' the Ranatra
linearis^ the house bug, and a few others which, on account of
peculiarities in their structure or habits, have found places in most
manuals of microscopy, are almost the only species with which a
vast number of naturalists are well acquainted, and we are yet
greatly deficient in reliable information as to the development, the
diagnosis of the larva, and the conditions under which the species
live in the different stages of their existence.

The species of the Hemiptera diifer greatly in shape and also
in colour, bright green, black, red, brown, yellow, grey, etc., being
all prevalent, and the generic characters, especially in the Capsidce,
require much patience and care in examination to ensure the
correct placing of a specimen.

The great majority of the Hemiptera are vegetable feeders,
inserting their rostra much after the manner of their victims, the
aphides, into the softer structures of plants, and sucking up the
juices through the delicate tubular setae, to be presently described.
It has, however, long been known that some species are carnivor-
ous, though curiously enough this character has been entirely
denied to the CapsidcE by most naturalists. Even Mr. Saunders,
in his lately published work, says : — " All species occur in summer
and early autumn, and subsist on the juices of leaves, etc."

Some few species are said to associate with ants, Mr. Douglas
having found them in the nest of Forinica rubra, and these may

ENEMIES OF APHIDES. 159

thus come under the notice of the student of the Aphididce, which
affect a similar habit.

In walking round a country garden on a summer or autumn
morning, one is almost sure to see on some of the dewy leaves a
bright little fly of an elegant and narrowed form, almost emerald-
green in colour, the iridescence of whose wing points, and the
delicacy of whose slender antenna render it an object of beauty.
It is probably a member of the genus Miris, and although not
itself an aphis-eater will serve to convey to an unfamiliar reader
the nature of the insects now under review.

The Hcmiptera Heteroptera are most conveniently considered
under the sectional denominations of Geocores, or ' land bugs,' and
Hydrocores, or 'water bugs.' The former, with which alone we
are concerned, are distinguished from the latter by the presence of
prominent antennae, organs which in the water bugs are minute
and usually concealed in the hollows of the faces of the insect.

The numerous families will be presently detailed, but so far as
I am aware two only can be at present certainly shown to be
aphis-eaters — namely, the Atithocoridcp. and the Capsidce. Mr.
McLachlan mentions in the Ent. Froc, 1879 — 80, that the
LygeidcB are also aphis-eaters, and it is not impossible, as the family
is known to include some insectivorous species ; but I have not
myself been able to obtain any definite evidence on the point.

The Anthocoridce are among the most common of the species,
and may usually be found in summer on any hedgerow. Saun-
ders, in his monograph of the Heteroptera, describes them gener-
ally as aphis-eaters ; but I cannot satisfy myself that the habit
extends to any species except A. sylvestris (Lin.) and probably
A. memoralis (Fabr.), which appears to have been occasionally
confused with the former species, under the specific designation,
nevioriim.

The CapsidcB are usually considered to be vegetable feeders,
and are so described by Kirby (^Entomology, 203), and the opinion
appears to have been generally accepted. Mr. McLachlan, how-
ever, in the paper above referred to, mentions the family as aphi-
divorous, and I have myself repeatedly met with Capsus lanartus
in its larva and nymph stages sucking the juices of aphides. Mr.
C. J. Watkins has related to me some similar instances, and Mr.

160 PREDACIOUS AND PARASITIC

J. W. Douglas, in the Ento. Monthly Mag. for Oct., 1895, gives so
exact a description of the attack that I venture to transcribe it : —

" Capstis lanarius feeding. — This species, like all other Cap-
sidcE, is credited with being a feeder on the juices of leaves, and I
was therefore somewhat surprised yesterday to see one individual
that was not a vegetarian. On the flower umbels of a Heracleum,
the stems of which were literally covered by the larvae of a pale-
green aphid, the Capsiis stood motionless, rostrum exerted and
arched, the tip in the body of one of the aphids, and so gently
inserted (after the manner in which Isaac Walton advises a hook
to be passed into a worm), that there was no resistance by the
victim. If this was the beginning of a feast, there was an abun-
dant supply of the delicacy to continue the revel, which in the
nature of things could not last long." Mr. Douglas also gives some
later observations of the same fact, and it may be considered to
be established beyond question that this particular Capsid at least
enjoys a carnivorous diet.

In the spring of 1895 I ^'^^ fortunate enough to secure a spe-
cimen of C. lanarius (larva) attacking an aphis, and after watching
it turn suddenly over the edge of the leaf and insert its rostrum
into the victim I removed the fragment of leaf, and mounted it at
once in a deep cell with the two insects still in situ., and the beak
of the capsid plunged deeply into the abdomen of the pear aphis
before it. The insects, as taken, are shown in the central figure
of Plate VIII.

Before proceeding to examine these insects in detail, it will be
desirable to show their position in systematic classification instead
of, as in previous groups, leaving this until the last section. My
object in so doing is to enable readers who have not made a special
study of the order to realise the relations of the species which
will be investigated.

The following synopsis of the Insecta, with especial reference
to those groups which are nearest to the Homoptera-Heteroptera,
will be useful in this direction : —

ENEMIES OF APHIDES.

161

a

•4— '

t/T J2
en 3

<5

f COLEOPTERA,

I including Strepsiptera
I Orthoptera,
j including Thyanura.
-| Neuropteka, includ-
I ing Trichoptera,
I Thysanoptera, etc.
I Hymenoptera.
1 Mallophaga.

r

Si

^ J ^ 13 .2 J

S XI 3 <^

3

I

,-i tn w

-530

rt

-H

Lepidoptera.
Diptera.

Hemiptera.

Aphaniptera.

Anoplura.

-1

I

f Cicadidae
j Cercopidae.
I Psyllidce.

Sub-order, -^

Homoptera | Aphididae.

i^Coccidae.

f Pentatomidae
I Coreidae
I Berytidae
I Lygeidse.

Reduviidae.

Saldidae.

Tingididas.

Aradidae.

Cimicidae.

Capsidae.

Hebridae.

Hydrometri-
Sub-order, dae.

Heteroptera-| Naucoridae.
I Nepidae.
I Notonectidae
l^ Corixidae.

Kirby, in his Entomology, has defined the Hemiptera as " haus-
tellate insects, wings four, membranous, naked. The fore-wings
(in the Heteroptera) of a parchment-like consistency (^except
sometimes at the tips), or (in the Homoptera) similar to the hind
wings ; metamorphosis incomplete ; and in one group (Aphides)
exhibiting alternation of generations." The He7niptera-Ho7nop-
tera he defines as follows : — " Fore-wings horny ; hind wings and
usually the tips of the fore-wings membranous; antennae usually
long, 4 or 5 jointed ; head generally free."

This division includes the true Bugs, an extensive group of
very varied structure and habits. The greater part of the terres-
trial species feed on plants. A few, however, are carnivorous,
feeding on other insects or sucking the blood of animals and birds,
and most of the aquatic species are likewise carnivorous. Kirby
divides the sub-order into 15 families : —

International Journal ok Microscopy and Natural Science.
Third Series. Vol. VI. L

162

PREDACIOUS AND PARASITIC

I. — Scutellaridse.

9--

— Emesidae.

2. — Coreidae.

10.-

— Saldidae.

Z.—Lygeid(B.

II.-

— Hydrometridae

4. — Phyrrocoridse.

12.-

— Gerridse.

5. — Capsidce.

^3-

— Galgulidae.

fi. — Tingididae.

14.-

— Mepidse.

7. — CimicidcB.

15-

— Notanectidse.

8. — Reduviidse.

Gymnocerata.

Pentatomidce.

The three families containing aphis-eating genera I have
italicised, and on the authority of Mr. McLachlan have included
the Lygeidse.

Mr. Saunders, in his exhaustive Monograph of the Heieroptera,
gives the following tabular statement of characters and families,
which will assist in tracing the position of any species which may
be found preying on Aphides : —

Table of Families.
I. — Antennae free, not hidden
2. — Abdomen, not clothed beneath with a

silvery pubescence, species not aquatic.
3. — Scutellum, reaching at least to the base

of the membrane
4. — Scutellum not reaching to the base of the

membrane (except in Aradidae)
5. — Mesoplurae and metapleurae, composed of

one piece only, elytra without a cuneus.
6. — Tarsi, 3-jointed.
7. — Rostrum, not bent at base, lying in repose

against the under surface of the head...
8. — Antennae inserted above a line drawn from

the centre of the eye to the apex of the

face
9. — Legs not very long, and slender femora

not clavate at the apex ... ... Coreida.

10. — Legs very long and slender, femora

clavate at the apex ... ... Berytidce.

Antennae inserted below a line drawn from

centre of eye to apex of face ... Lygeid(B.

1 1

ENEMIES OF APHIDES.

163

12. — Rostrum stout, bent at the base so that it

does not lie against the under surface of

the head in repose
13. — Rostrum long, ocelli placed between the

eyes
14. — Rostrum short, ocelli placed behind the

eyes
15. — Tarsi, two-jointed.
16. — Anterior legs, inserted on the posterior

margin of the prosternum ...
^7. — Anterior legs, inserted in the disc of the

prosternum
18. — Mesoplurae and metaplurge, composed of

several pieces, elytra with a cuneus
19. — Elytra with an embolium
20. — Elytra without an embolium ...
21. — Abdomen clothed beneath with a silvery,

velvety pubescence ; species aquatic or

sub-aquatic
22. — Antennae, five-jointed
23. — Antennae, four-jointed
24. —Antennae hidden in foveae under the head
25. — Anterior legs inserted on the disc or

anterior margin of the prosternum ...
26. — Antennse, with four simple joints, no anal

appendix
27. — Antennae with three joints, abdomen with

a long anal tubular appendix
28. — Anterior legs inserted on the posterior

margin of the prosternum ...
29. — Rostrum, free, three- to four-jointed
30. — Rostrum, hidden, apparently unjointed...

This arrangement of families corresponds very nearly with that
of Kirby, and may be accepted as having the support of all
naturalists who have devoted attention to the species of Heterop-
tera found in this country. The two families of Cimicidte and
Capsidce, which are the only ones, the aphis-eating proclivities of

Saldidce.

Reduviidce.

TingididcE.

Aradidce.

Cimicidce.
CapsidcE.

Hebrides.

HydrometridcB.

Cryptocerata.

Naucoridce.

Nepidce.

Notonectida,
Corixtdce.

164

PREDACIOUS AND PARASITIC

some of whose species has been demonstrated beyond doubt, have
been divided by the same patient and illustrious naturalist under
the following heads : —

Anthocarina (one of the four sub-families of the Cimicidce).

Genera.
I. — Third and fourth joints of the antennae

very fine and thin, clothed with long,
erect hairs ... ... ...

2. — Anterior femora, hardly thicker than the

intermediate pair ... ... ... Lyctocoris.

3. — Anterior femora incrassated, much thicker

than the intermediate pair ... ... Piezostethus.

4. — Third and fourth joints of the antennae,
scarcely or not thinner than the preced-
ing, hairs not long and erect
5. — Cell of the wing, with a hook-like nerve...
6. — Pronotum, with a distinct apical collar ...
7. — Apex of the metasternum between the

coxse, widely truncate
8. — Rostrum, reaching to the intermediate

coxae
9. — Rostrum, not reaching beyond the centre

of the mesothorax
10. — Apex of melasternum, rounded and nar-
rower
II. — Rostrum short, hardly reaching beyond

the anterior coxse
12. — Apical collar of pronotum long, sides

gradually diverging from it ... Anthocoris.

13. — Apical collar short, sides widely rounded

behind it ... ... ... Teiraphleps.

14. — Rostrum reaching to the intermediate coxae Acompocoris.
15. — Pronotum without a distinct collar Triphleps.

16. — Cell of the wing, without a hook-like

nerve
17. — Species robust, pubescent
18. — Head short, scarcely longer than its width

between the eyes ... ... Brachy steles.

Temnostethus .

Elatophilus.

ENEMIES OF APHIDES. 165

19. — Head much longer than its width between

the eyes ... ... ... Cardiastdhus.

20, — Species elongate, glabrous, parallel-sided. Xylocoris.

The only one of these genera which is definitely shown to
comprise aphis-eating species is Ani/wcoris, but it seems probable
that continued observation may reveal the same habit in others,
particularly in Tetraphleps (Fieb.) and perhaps Acompocoris (Reut.).
The genus Piezostethus (Fieb.) contains one species, L.formicetorum
(^Boh.), which appears to find a suitable home in the nests of
Formica rubra. Hence, it may be found under these conditions
in company with aphides possessing the same habit.

The details of the genus Anthocoris will be given later on.
The family Capsidce — which, although very often stated to
contain vegetable feeders only, includes, as has been mentioned,
several genera of more or less carnivorous proclivities, whilst the
species of two genera can be demonstrated to consume aphides
as ordinary food. It is a numerous family, exhibiting a great
variety of structure, of environment, and habit ; but the patient
observation of the student is not unlikely to be rewarded by the
addition of some of its genera to the list of Aphis-eaters, in
addition to those of Capsus and Plagiognathiis.

The following tabular account of the genera of the Capsidce. is
taken from Mr. Saunders' exhaustive work : —
I. — Head channelled in the centre or trans-
versely impressed on the vertex ; ante-
rior margin of pronotum not callosely
raised ...
2. — First joint of the posterior tarsi much

longer than the second
3- — Head channelled down the middle
4. — Base of pronotum truncate, covering the

base of the punctured scutellum .,. Miris (Fab.).
5- — Base of pronotum emarginate, not
covering the base of the impunctate
scutellum ... ... ... Megalocera:a{¥\Q!o.)

6. — Head transversely impressed on vertex..
7- — Eyes not, or scarcely, projecting beyond

the lateral margin of the pronotum ... Acetropis (Fieb.).

166

PREDACIOUS AND PARASITIC

8. — Eyes prominent, projecting considerably
beyond the lateral margins of the
pronotum
9. — Elongate, depressed, glabrous above, or
nearly so

10. — Elongate, not depressed, clothed with
erect hairs

II. — First and second joints of posterior
tarsi, sub-equal ...

1 2. — Head not channelled nor transversely
impressed

13. — Pronotum, with the anterior margin
raised and rounded, or constricted into
a short collar-like neck, or much con-
stricted in front and widened behind,
with the sides sinuate, and the poste-
rior margin largely emarginate

14. — Pronotum, with the lateral margins acute
in front, anterior margin not callose...

15. — Eyes very prominent, species parallel
sided, black and yellow, or red

16. — Eyes not very prominent, species oblong
ovate, ochreous with brown stripes ...

17. — Pronotum with the lateral margins not
acute in front, or with the anterior
margin callose ...

18. — Pronotum gradually raised and rounded
from the narrow anterior collar to the
base, its sides rounded or straight,
rarely sinuate, base not largely emargi-
nate ...

19. — Membrane with two cells

20. — Large or medium-sized species ; neck
more or less swollen, head not divided
from it even at the sides by a carina
or raised line

21. — Rostrum produced beyond the posterior
coxae ...

Teratocoris ( Fi e b . ) .

Leptoptenia (Fieb.).

Pantilus (Curtis).

Lopus (Hahn).
Miridius (Fieb.).

ENEMIES OF APHIDES. 167

22. — Membrane marbled ... ... F/iy focoris (Fa\\.).

23. — Membrane not marbled ... ... Oficognai/ius (Fieh.).

24. — Rostrum not produced beyond the pos-
terior coxse
25. — Species not deeply punctured nor rugose
26. — Second joint of antennae not clavate ... Calocoris (Fieb.).
27. — Second joint of antennae strongly clavate Rhopaltomus (Fieb.).
28. — Species deeply punctured or rugose ...
29. — Surface glabrous, both sexes macropterous Capsus (Fab.).
30. — Surface hairy, female generally brachy-

opterous ... ... ... Bothynotus{T\eb.).

31. — Medium-sized or small species ; vertex of

head completely or only in part (near

each eye) divided from the neck by a

transverse carina or rounded margin...
32. — Vertex carinated, at least near the eyes.
33. — Hemelytra and nervures of membrane,

scarlet ... ... ...Dichrooscytus{Y\&h.).

34. — Hemelytra not scarlet

35. — Pronotum scarcely convex, transversely

rugose, elytra glabrous ... ... Flesiocorts {Y'xth.).

36. — Pronotum convex, not transversely rugose,

hemelytra more or less pubescent ...
37. — Species not clothed with scattered,

deciduous, golden pubescence
38. — Head very wide, rostrum reaching beyond

the posterior coxae ... ... Zygimus {Y\eh.).

39. — Head not very wide, rostrum reaching

to about the posterior coxae . . . Lygus (Hahn).

40. — Species clothed with deciduous golden

pubescence ... ... ... Fceciloscytus {Y'leh.).

41. — Vertex not carinated, but with a rounded

margin posteriorly, visible especially

near the eyes, elytra glabrous
42. — Second joint of the antennae shorter than

the third and fourth together ... Liocoris (Fieb.),

43. — Second joint of antennae longer than

the third and fourth together Camptobrochis (Fieb.).

168

PREDACIOUS AND PARASITIC

48.

49-

50-

Pithanus (Fieb.).

44. — Membrane with only one cell.
45. — Third and fourth joints of antennae sub-
equal ... ... ... Bryocoris (Fall.).

46. — Third joint distinctly longer than fourth MoHa/ocoris(Dsih\h.).
47. — Pronotum constricted in front, raised and

widened posteriorly, sides generally

sinuate, base largely emarginate
Basal joint of posterior tarsi nearly three

times as long as the second
Basal joint of posterior tarsi not much

longer than the second
Eyes touching or nearly touching the

anterior margin of the pronotum
51. — Third and fourth joints of the antennae

not, or scarcely, thinner than the apex

of the second ...
52. — Antennae somewhat robust, head with a

slight vertical impression in the centre

posteriorly
53. — Antennae slender, vertex not impressed.
54. — Head between the eyes flat, lower than

the eyes
55. — Head between the eyes, convex, higher

than the eyes ... ... Campjy/oneura (Fieh.),

Third and fourth joints of the antennae,

much thinner than the apex of the

second.
Second joint of the antennae as long, or

nearly as long, as the third and fourth

together
58. — Callosities of pronotum scarcely promi-
nent, elytra in both sexes fully deve-
loped
Callosities of pronotum very prominent,

elytra in female generally not fully

developed
Second joint of antennae, much shorter

than the third and fourth together ...

Allodapus (Fieb).

^torhinus (Fieb.).

56

57

59

60

Cyllocoris (Hahn).

Globiceps (Latr.).

ENEMIES OF APHIDES. 169

6i. — Face nearly perpendicular — i.e., nearly

at right angles to the vertex, wing-cells

without a hook-like nerve ...Mecoffima (Fieb.) and

Cyrtorrhinus (Fieb.).
62. — Face declivous, not nearly at right angles

to the vertex, wing-cells with a hook-
like nerve ... ... ... Byrsoptera {^y^vcs..).

63. — Eyes not nearly touching the anterior

margin of the pronotum ...
64. — Head constricted behind eyes ; eyes »

large ...
65. — Posterior femora grooved ... ... Syst£l/onotus{¥\e\:).).

66. — Posterior femora, not grooved .. Bicyphus {Yieh.).

67. — Head not constricted behind eyes ; eyes

small ... ... ... ... Macrolophus {¥\eh.).

68. — Pronotum with anterior margin not raised

and rounded, nor constricted into a short,

collar-like neck, nor much constricted

in front and widened behind in the same

species, where the sides are sinuate and

the base widely emarginate
69. — Eyes not nearly touching the anterior

margin of the pronotum ... Malacocoris {V'lth.).

70. — Eyes quite or nearly touching the pro-
notum
71. — Head posteriorly very thin and flat,

covering the apex of the pronotum;

posterior tibiae somewhat flattened

and curved ... ... ... Pi/op/iorus (Hahn).

72. — Posterior tibiae, not curved and flattened
73. — Wing-cell without a hook-like nerve ...
74. — Head posteriorly more or less covering

the front of the pronotum
75. — Antennae nearly twice as long as the body Halticus (Hahn).
76. — Antennae short, not so short as the body Strongylocoris {Cost.)
77. — Head not covering the pronotum in front
78. — Species black, clothed with scattered

golden or silvery deciduous, scale-like

pubescence

170

PREDACIOUS AND PARASITIC

Heterotoma (Latr.).

Loxops (Fieb.).

79.— Tibiae with spine like hairs . Orthocepkalus {Y'l&h.)

80.— Tibise without spine-like hairs ..Heterocordylus (Fieb.).

81. — Species not clothed with golden or sil-
very deciduous, scale-like pubescence.
82. — Second joint of antennae much dilated

and flattened
83. — Second joint of antennae not dilated

and flattened
84. — Second joint of antennae very long, one-
half longer than the third and fourth

together
85. — Second joint of antennae, not or scarcely

longer than the third & fourth together
86. — Third and fourth joints of the rostrum,

together longer than the second, not

incrassated
87. — Third and fourth joints of the rostrum,

together not longer than the second,

each slightly thickened towards their

juncture
88. — Wing cell with a hook-hke nerve (want-
ing in some specimens of Asciodetna

obsoletum)
89. — Elytra opaque, dull, or at most only very

slightly shining, never clothed with

pale, deciduous, scale-like pubescence.
90. — Tibise spotted with black
91. — Tibiae not spotted with black
92. — Claws exceedingly short, strongly curved,

with an acute tooth at the base
93. — Claws not very short and not strongly

curved, without an acute basal tooth
94. — Arolia longer than the claws ...0?iychu)ne?ius{R.&\xl.).

95. — Arolia shorter than the claws
96. — Rostrum very long, extending beyond

the posterior coxae ... ... Amblytylus {Yiob.).

97. — Rostrum not very long, not extending to

the posterior coxae

Orthotylus (Fieb.).

Hypsitylus (Fieb.).

Oncotylus (Fieb.).

Macrotylus (Fieb.).

ENEMIES OF APHIDES. 171

98. — Upper surface with fine, pale, regular

pubescence, spines sub-elongate ... Co fios^ef /lus [Fieh.).
99. — Upper surface clothed with brown or

black hairs, mixed with paler spines;

sub-robust
100. — Antennae with the third and fourth joints

very little thinner than the second ... Ifop/omacAus (Fieh.).
loi. — Antennae with third and fourth joints

much thinner than the second ... J'Jacroco/eus (Fieh.).

102. — Elytra shining, often clothed with pale,

deciduous, scale-like pubescence
103. — Second joint of antennas shorter than

the third ... ... ... Harpoceni (Curtis).

104. — Second joint of the antenna longer

than the third ...
105. — Tibiae with pale spines

106. — Elongate, depressed, elytra parallel-sided Phyllis (Hahn).
107. — Not elongate and depressed, elytra

with sides rounded ... .. Flesiodema {KenX..).

108. — Tibiae with black spines
109. — Elytra clothed with short, deciduous,

scale-like pubescence
1 10. — Second joint of antennae in both sexes,

incrassated ... . . ... A iracto to mus (Fieh.).

III. — Second joint of antennae, not incrassated Psalliis (Fieb.).

1 12. — Elytra clothed with fine regular hairs...

113. — Femora enthely pale ... ... Asa'odema (Reut).

114. — Femora more or less dark, or spotted

with black or brown . . . Plagiognathics (Fieb. ).

The genus Capsus (Fab.) contains but two species found in
Britain, and in all probability both are aphidivorous, although up
to the present I have only observed, or been able to find, record
of the first. The genus consists of strongly characterised species,
dark-coloured black, red, and reddish brown in colour. The eyes
project greatly, and the second joint of the antennae is consider-
ably thickened towards its extremity ; the two last joints are not
more than half the diameter of the second, often less, and toge-
ther do not exceed it in length — generally are shorter. The elytra,

172 PREDACIOUS AND PARASITIC

pronotum, and scutellum are strongly punctured, and the spines
of the tibige are very small.

The two British genera are as follows : — ■

Capsus lafiarius (Linn.). Robust, oval, black, reddish black
or brown, shining. Femora black to pale in varying proportions ;
tibiae pale to brown ; coxae large, brown to yellowish. Antennae
black, with portions of second joint and two final joints pale, all
clothed with fine hairs. Anterior aspect of pronotum in propor-
tion to base in about i to 3 or i to 4 ; angles of base rounded,
black or stone-coloured yellow ; scutellum black or similar yellow,
very prominent ; both pronotum and scutellum thickly punctured.
Elytra black to brown or yellow, with a bright red patch oncuneus.
Portions of corium often dull red, all variably punctured ; cuneus
with a few stiff bristles, apex black usually ; membrane dark, with
curved vein partly red. The lighter specimens seem to be gene-
rally females, and are furnished with an ovipositor dividing the
posterior segments of the abdomen beneath. Mr. Saunders
mentions that all his dark examples are males. The species is
widely distributed, and may be found in gardens and on nettles,
etc. The length of the larva is about o"2 to 0*22, the nymph
about o'22 to 0*25 in.,' and the mature insect measures about 0*25
to o'3 in. in length, and 0*5 to o'6 in. across the expanded wings.

Capsus scutellaris (Fab.), black, somewhat longer than C. lana-
rius, bright shining, with narrow red line on head and scutellum
(generally). Pronotum thickly and deeply punctured ; scutellum
smooth, prominent, shining, and unpunctured ; elytra much as in
C. lanarius, except for the patch on cuneus, and more closely
punctured ; membrane dark, not spotted. I have not seen the
larval form of this species, which is rare. The nymph measures
some 0*25 to o"266 in. in length, and the imago o'3 to 0*35 in.
These measurements are made on the male insect. The female
is said to be slightly less. Widely distributed, but rare. Mr.
Saunders has taken it on heather. I have found it on garden
plants in the country.

The Anatomy of Aphidivorous Hemiptera.

The anatomy of the Capsidae and of the Hemiptera generally
presents some striking departures from the general structure of the

ENEMIES OF APHIDES. 173

otiier orders, and minute as many of these insects are the details
of their organisation are as much calculated to fill the observer
with surprise as those of the more bulky Blow-Fly, which Lowne
has described with such wonderful minuteness, or the Cockchafer,
the organs of which are modelled in wax by Auzoux, and have
attracted the learned and the curious on both sides of the Atlantic.

The despised ' bug,' however, is not less worthy of the skill of
the dissector and microscopist, and presents so many features of
interest in its larval and nymphal stages, that a fully detailed
account would probably exceed the bulk of Lowne's classical
work, and would certainly try the patience of the ordinary reader.

The characters of the Capsidse are well marked, the structure
of the antennae, the absence of ocelli, and the details of the
hemelytra serving to readily distinguish them. I have shown
upon PI. VII., at Figs, i, 2, and 3, the larva, nymph, and imago
of Capsus lanarius, and at Figs. 4 and 5 the coriaceous hemelytra
and the membranous posterior wings. On Plate VIII. the details
of the head and of the rostrum and some other parts are pre-
sented to the reader.

The Larva.

I have not been fortunate enough, in spite of much searching,
to secure any specimen of the larva in its earliest stages of exist-
ence. At a few days old it is somewhat linear in aspect (as com-
pared with the later forms). The abdomen, though flask-shaped,
is flattened laterally, and the obtuse prominences apparent on
either side of each segment, and in parallel lines upon the dorsal
surface of the abdomen, stand much more revealed than in the
stouter abdomen of the nymph, though, as in the latter, they are
each tufted with a group of very curious flattened bristles, each
one divided at its extremity into two or three points. These
bristles are shown on Plate VIII., at Fig. 13, and from their flatness
and the peculiar nature of their attachment to the epidermis are
the most obvious and striking feature of the species. They do
not appear to answer the purposes of ordinary hairs or bristles, for
unlike these their attachment to the skin is slight, and although
the solid-looking, chitinous ring or cup on the epidermis, which
forms their base, would seem to indicate an important organ, yet

174 PREDACIOUS AND PARASITIC

slight pressure or friction suffices to detach these curious appur-
tenances. I have been inclined to imagine that they were hollow
tubes, which, originally cylindrical, as appears from the form of
the base, had collapsed, from the delicacy of the membrane of
which they were found ; but an extended observation scarcely
supports this view. Bristles of a similar form and structure are
sparsely scattered on the general surface of the abdomen, thorax,
and head, and one or two are generally found on the femora and
a few on the first joints of the antennae. Hairs and bristles of
ordinary tapering form are intermixed, the proportion increasing
on the femora and thicker joints of antennae, whilst finer hairs are
alone found on the tibiae and terminal antennal joints.

The head in the larva has a much more pointed form than in
the nymph or imago, the apex being formed by the base of the
rostrum and the rather long-pointed labrum, which is folded down
closely upon it. The antennse exhibit but little difference in the
size of the joints, the characteristic development of the two first
belonging more especially to the nymphal stage. The quasi-caudal
appendage, on the other hand, is remarkably prominent in the
larva, and has the form of a short, truncated cone, which is often
marked with longitudinal stripes on either side.

The Nymph.
The second (or possibly the third) casting of the larval skin
reveals the wing-pads which indicate the nymph, and at this stage
the abdomen assumes its fuller flask-shaped form, and the thorax
becomes wider and shaped in a more suitable way for the support
of the wings. The first and esjjecially the second joints of the
antennae are more bulky, and the latter exhibits a marked increase
of size towards its anterior extremity. The rostrum, however, is
but little different from that of the larva. The details of this
organ are shown on Plate VIII., Figs. 2 and 3, representing the
upper and under side of the head, with the organ folded down
upon the ventral surface of the thorax, as when at rest. The pro-
tuberance of the labrum and the numerous flattened bristles are
noticeable features. In Fig. 4 the rostrum is shown, with the
piercing organ raised from the sheath, formed between the lobes
of the fleshy labium, for to this organ in the diptera the fleshy

ENEMIES OF APHIDES. 175

portion of the rostrum corresponds. In Figs. 5, 6, 7, 8, and 9,
the rostrum is shown in detail. It consists, as to its main struc-
ture, of two elongated fleshy lobes in four segments, which are
closely united on the underside (assuming the rostrum to be
extended); but on the upper surface form a deep groove, within
which are the delicate setse which constitute the piercing organ.
The rostrum takes its rise in, or rather is a prolongation of, the
front portion of the head, which is hollowed out on the underside
so as to receive the organ when in repose, and folded back beneath
the thorax.

When the rostrum is extended, the cavity thus formed is
covered by a membrane, no doubt of a muscular nature, which at
such times becomes tense and rigid, and which is continuous with
the skin of the rostrum. The extremities of the labial lobes, as
showii at Fig. 9, are two small, cushion-like organs, bearing each
several stiff hairs, and which are all that represent the extensive
labial terminations of the Diptera. Within the groove terminated
by these cushions lie the four setse constituting the alimentary
apparatus. They consist of fine chitinous blades, the two central
ones being nearly flat, parallel-sided lancets of great length, and
much resembling in form the blade of a narrow sword. Each of
these is grooved on the opposing faces, and the two sections
pointed at the extremity and working one against the other form
not only the weapon by which the prey is struck, but the passage
by which the ingestion of the victim's juices is accomplished.
The sharp and channelled extremities of these piercing setse are
shown at Fig. 7, and observation has satisfied me that in action
they operate by a sliding action one upon the other, this being
probably given by the alternate compression and dilation of the
spiral muscular bundles enveloping the pharynx, as seen in Fig.
10. The two remaining setse are thin and hollowed throughout
so as to form sheaths, which, closing in on either side, protect the
lancet setse throughout their entire length. These sheaths are
shown in Fig. 6 in their natural position, and the extremity of one
from an allied genus is more highly magnified at Fig. 8. Towards
the extremity they are more or less serrated, or sometimes provided
with knobby protuberances, and the thin edges, which frequently
overlap, are ribbed and notched in a definite pattern, in order,

176 PREDACIOUS AND PARASITIC '

doubtless, to assist in securing the organ in position in the body
of the victims of attack.

The insertion of the setge in the skin of the aphis or other
insect being accompHshed, these serrations give a secure hold, and
enable the channelled lancets within, sliding one upon the other
by the action of the spiral muscles at the base of the rostrum, to
extract at leisure the juices of the body without disturbance or the
possibility of escape for the victim. It is generally considered
that these four setae should be taken to represent the mandibles
and maxillae of the Diptera and Hymenoptera ; but this view does
not seem to take cognisance of the resemblance in structure
between the grooved lancets and the narrow grooved, horny ligula
of the Diptera. It seems to me that the upper of the two lancets
may represent the united and elongated mandibles, whilst the
lower is most probably the representative of the ligula. All four
setae take their rise from among powerful groups of muscles,
situated in either side of the head, and as shown in Fig. lo are so
divergent as to give each one an entirely independent point of
support, while, centrally placed among them, the tube of the
lancets is continued as a pharynx surrounded by spiral muscles,
which, by their contraction or elongation, would be capable of
producing a powerful pumping action exactly suitable to the
action of the lancets.

The coxae, and especially the anterior pair, are very largely
developed in the Capsidct, and as this feature is generally evident
in the earlier stages of the insect's existence, it may often assist in
determining the position of an unknown larva or nymph. The
tibiae, alike in the nymph and imago, are slender, and usually,
though not always, possess a fringe of five spines, and the tarsus
is in all genera three-jointed. The posterior protuberance is less
prominent in the nymph than in the larva, but presents much the
same features ; but the ventral surface of the abdomen, in all
those Capsida which I have examined at this later stage, shows in
the female an axial ridge sufficiently indicative of the future ovi-
positor. The tufted prominences on the upper surface of the
abdomen are, in the species illustrated, marked by dark spots of
irregular size, and to get a proper observation of these a specimen
should be treated with potash and mounted in Canada balsam,

Journal of Microscopy. 7r-- Ser. Vol. 6> Plate 7.

f^^T"*^??!^^-??"---??;:.-:-.

F Phillips Sc.

Journal of !Vlicrosco]jy.

■■-ay 1 '

K

3^^Ser.Vol, G, Plate 8.

H.CA.Vin&, ad not del.

CapsiL-s L cLTuiri-iA^s oO&C'CiUs

F. Phi/lips <So.

ENEMIES OF APHIDES. 177

as otherwise the opacity of the insect hinders any but the lateral
prominences from being apparent.

EXPLANATION OF PLATES VIL & VIII.

Plate VII.

Aphidivorous Hemiptera. Illustrations of Capsus lanarins (Linn.).

Fig. I. — Capsii,s lanarins, larval stage. The stiff, flattened bristles are
a very noticeable feature at this stage. The thickening of
the second joint of the antenn.e is not yet apparent, but the
labrum and rostrum are strongly developed.

,, 2. — C. lanarius, nymph or pupa stage. Here the development of
the wing pads, the thickening of the second joint of the
antennyp, and the widening of the abdomen are very apparent
features.

,, 3. — C. lanarius, imago, a. Vertex ; b, prothorax (the upper
surface seen is the prouotum) ; c, mesothorax (the only por-
tion of this visible is the triangular scutellum) ; d, raetathorax
(this is not visible with the wings closed) ; e, hemelytra ;
f, membrane of hemelytra.

J? 4. — C. lanarius, hemelytron. a, Clavus ; b, corium ; c, cuneus ;
d, membrane. The surface of the corium is deeply pecti-
nated.

,, 5. — One of the membranous posterior wings of same.

Plate VIII.

Fig. 1. — The attack of Capsus lanarius (larva) on a Pear Aphis. The
capsid, coming suddenly over the edge of the leaf, has trans-
fixed the aphis with its rostrum,

)> 2. — Head of C. lanarins (larva) from above. The projection of
the labrum beyond the vertex and covering the base of the
rostrum is very noticeable, and also the flattened bristles of
the epidermis.

,, 3. — Head of same from below, exhibiting the position and forma-
tion of the rostrum.

>i 4. — The rostrum, showing towards the base the labrum, a, and at
b the conjoined setse, lifted out of the groove in the labial
sheath.

?) 5. — The four setse, removed from the rostrum ; the two exterior,
sheath-like setae (apparently corresponding to the maxillae
in mandibular insects), separated from the central piercing
organ.

>j 6. — The extremity of the closed setse, as they appear in a nearly
related genus.

ji 7. — The extremity of the actual piercing setse (apparently homo-
logues of the mandibles and ligula), showing the grooved and
sliding structure.

Internatiox\al Journal of Microscopy and Natural Science.
Third Series. Vol. VI. M

178 REMARKABLE TREES.

Fig. 8.— The extremity of one of the maxillary setae,

,, 9.— The extremity of the fleshy sheath of the rostrum, showing
the minute terminal pads corresponding to the labial lobes of
the diptera.

,, 10. — The muscular structure within the base of the setse, showing
the spiral arrangement of the muscles which enclose the
l^harynx.

,, 11. — Antennae of C. lanarius, showing the enlarged second joint.

,, 12. — The two terminal joints of antenna (nymph), enlarged.

,, 13. — A group of characteristic flattened bristles, situated in tufts
on the sides of the abdomen of larva and nymph.

,, 14. — Tibia and tarsus of Capsus lanarius.

IRcmarJ^able Zvcce.

IN the Old World the greatest tree is the African Baobab, and
in the !<iew World the Wellingtonia. At the mouth of the
Senegal River specimens of the Baobab have been measured
of over one hundred feet in circumference, though it is never more
than sixty feet in height and becomes hollow at an early age. Dr.
Livingstone found one in which thirty men could sleep comfort-
ably ; and Humboldt tells of one in Senegambia wherein the
negroes held their meetings. Adamson has calculated that some
of these trees must be at least 5000 years of age, by which time
they are thirty feet in diameter.

Among curiosities there is the bottle tree of Brazil, which
swells from a slender base until, at half its height, the diameter is
equal to the altitude, a similar genus being found in tropical
Australia,

We must mention the so-called " living stones " of the Falkland
Islands, where, owing to the strong Polar wind, it is impossible for
trees to grow erect, so Nature has made amends by furnishing a
supply of wood in the most curious shape imaginable. Here and
there are to be found in the islands singular shaped blocks of what
appear to be weather-beaten and moss-covered boulders of various
sizes. These boulders cannot be turned over, they being tied to
the earth by roots of extraordinary strength. No other country in
the world has such a peculiar forest growth, and it is impossible to
work these odd-shaped blocks into fuel, because the wood is per-
fectly devoid of grain, and appears to be nothing but a twisted
mat of fibres. — IVm. Norman Brown in Gardener's Magazine.

[ 179 ]

Iperipatus, flD^riapobs, an^ 3n9cct9,'

VOLUME V. (the second in order of publication) of The
Cambridge Natural History has reached us, and we
are pleased to say that all we said in a former notice in
praise of the first issued volume may be said of this. The sub-
jects throughout are treated in a most pleasing and instructive
manner, and may be read with pleasure and profit by every
student of Natural History.

The first chapter treats of the small class, Prototracheata,
which contains the solitary genus, Peripatus, a lowly organised
animal and of remarkable sluggishness, with but slight develop-
ment of the higher organs of sense ; with eyes, the only function
of which is to enable it to avoid the light. Though related to
those animals most repulsive to the aesthetic sense of man — ani-
mals which crawl upon their bellies and spit at or poison their
prey — is, yet strange to say, an animal of striking beauty. The
exquisite sensitiveness and constantly changing form of the
antennae, the well-rounded plump body, the eyes set like small
diamonJs on the side of the head, the delicate feet, and, above
all, the rich colouring and velvety texture of the skin, all combine
to give these animals an aspect of quite exceptional beauty. .
They live beneath the bark of rotten stumps of trees, in the cavi-
ties of rock, and beneath stones. They require a moist atmo-
sphere and are exceedingly susceptible to drought. They avoid
light and are therefore rarely seen. They move with great deli-
beration, picking their course by means of their antennae and eyes.
• . . The antennae are extraordinarily sensitive, and so deli-

*"The Cambridge Natural History," edited by S. F. Harmer,
M.A., Fellow of King's College, Cambridge, Superintendent of the University
Museum of Zoology ; and A. E. Shipley, M.A. , Fellow of Christ's College,
Cambridge, University Lecturer on the Morphology of Invertebrates.

Vol. v., Peripatus, by Adam Sedgwick, M.A., F.R.S., Fellow and Lec-
turer of Trinity College, Cambridge. Myriapods, by F. G. Sinclair, M.A.,
Trinity College, Cambridge. Insects, Part I., by David Sharp, M.A.
(Cantab.), M. B. (Edin.), F.R.S. 8vo, pp. xi.— 584. (London: Macmillan
and Co. 1895.) Price 17/- net.

180 PERIPATUS, MYRIAPODS, AND INSECTS.

cate, indeed, that they seem to be able to perceive the nature of
objects without actual contact.

Chapter II treats of the class Myriapoda, a class of animals
which are widely distributed, and are represented in almost every
part of the world. Heat and cold alike seem to offer favourable
conditions for their existence, and they flourish both in the most
fertile and the most barren countries.

One of the most important characteristics which distinguish
Myriapods from other Arthropods is the fact that they possess, on
the posterior segments of the body, true legs which are jointed
and take part in locomotion. The head is in all cases quite dis-
tinct from the body, and may be regarded as a number of seg-
ments fused together into one mass. Their heads are always
provided with a single pair of antennse and mouth appendages,
consisting of an upper lip, a pair of mandibles or jaws, and one
or two pairs of maxillae.

Their internal structure has a great likeness to that of insects.
The general position of the internal organs may be seen from Fig.
II, which shows a Lithobius dissected so as to exhibit the digestive
and nervous system : —

The digestive canal, which is a straight tube, extends through-
out the whole length of the body, and terminates in the last
segment of the body.

The heart has the form of a long, pulsating, dorsal vessel,
which extends throughout the whole length of the animal. It is
divided into a number of chambers which are attached to the
dorsal wall of the body, and are furnished with muscles of a wing-
like shape, which are known as the alary muscles and which
govern the pulsations. The chambers are furnished with valves
and arteries for the exit of blood, and slits known as ostia for the
return of blood to the heart.

The remaining chapters of the book treat of the following
Orders of Insects, viz. : — Aptera, Orthoptera, Neuroptera,
and a portion of Hymenoptera,

Insects form by far the larger part of the land animals of the
world. They outnumber in species all the other terrestrial ani-
mals together, while, compared with the Vertebrates, their numbers
are simply enormous. Yet they attract but little attention from

PERIPATUS, MYRIAPODS, AND INSECTS.

181

the ordinary observer, this being probably primarily due to the
small size of the individual Insect, which leads the unreflecting to
treat the creature as of little importance. . . . The largest
Insects scarcely exceed in bulk a mouse or a wren, while the
smallest are almost or quite imperceptible to the naked eye, and

Fig. II.

Lithobius dissected
(after Vogt and Yung).

a, Antennse ;

b, Poison -claws ;

c, Brain ;

d, Salivary glands ;

e, Legs ;

/, Nerve cord ;

g, Malpighian tube ;

h, Malpighian tube ;

i, Vesicula seminalis ;

/, Accessory gland ;

k. Accessory gland ;

/, Testis ;

;«, Thigh-gland ;

«, Digestive tube.

yet the larger part of the animal matter existing on the lands of
the globe is in all probability locked up in the form of Insects.
Taken as a whole, they are the most successful of all the forms of
terrestrial animals.

182

PERIPATUS, MYRIAPODS, AND INSECTS.

The series of rings of which the external crust or skeleton of
Insects is composed exhibits great modifications, not only in the
various kinds of Insects, but even in the different parts of the
same individual, and at successive periods of its development.

Many of the anatomical structures have positions in the body
that are fairly constant throughout the class. Parts of the respira-
tory and muscular systems and fat-body occur in most of the
districts of the body. The heart is placed just below the dorsal
surface ; the Alimentary canal extends along the middle from the
head to the end of the body. The chief parts of the nervous

Fig. 12. — Diagram of Exterior of Insect.
The two vertical dotted lines indicate the division between H., Head;
T., Thorax; and A., Abdomen, a, Antennse ; h, Labrmn ; c. Mandible;
d. Maxillary palpus ; e. Labial palpus ; /, Facetted eye ; g, Pronotum ; h,
Mesonotum ; f, Metanotum ; /•, Wings; l\ to /lo, Abdominal segments;
w, The internal membranous portions uniting the apparently separated seg-
ments ; «, Cerci ; o. Stigma ; /, Abdominal pleuron bearing small stigmata ;
q\, qz, ql. Pro-, meso-, and meta- sterna; r, Metathoracic episternum ;
s, Epimeron, these two forming the mesopleuron ; r2, S2, Metathoracic epi-
sternum and epimeron ; /, Coxa ; v, Trochanter ; iu. Femur ; x, Tibia ;
y, Tarsus ; s, Gula.

system are below the alimentary canal, except that the brain is
placed above the beginning of the canal in the head. Fig. 13
shows the arrangement of some of the chief organs of the body,
with the exception of the muscular and respiratory systems, and
the fat-body.

PERIPATUS, MYRIAPODS, AND INSECTS.

183

Chapter V., which treats of the Development of Insects, is
most interesting. Although eggs are laid by the great majority of
insects, a few species nevertheless increase their numbers by the
production of living young, in a shape more or less closely similar
to that of the parent. This is well known to take place in the
Aphididas, or green-fly insects, whose rapid increase in numbers is
such a plague to the farmer and gardener. These and some
other cases only emphasise the fact that insectsv.are preeminently
oviparous. In illustration of this chapter we have chosen Fig. 14,
which represents the larva and pupa of a bee. It will be seen
that the difference between the two forms a very great contrast,
while the further change that will be required to complete the
perfect Insect is but slight. When the last skin of a bee or a

Fig. 13. — Diagram of arrangement of some of the Internal Organs of an Insect.
a. Mouth ; b, Mandible ; c, Pharynx ; d, CEsophagus ; e, Salivary glands
(usually extending further backwards) ;/, Eye ; g, Supra-oesophageal ganglion ;
h, Sub-oesophageal ganglion ; i, Tentorsum ; J, Aorta ; ki, k2, Z'3, Entothorax;
li to /8, Ventral nervous ganglion ; tn. Crop ; «, Proventriculus ; 0, Stomach ;
/, Malpighian tubes ; q, Small intestine ; r, Large intestine ; s, Heart ;
t, Pericardial septum ; ti, u. Ovary composed of four egg-tubes ; v, Oviduct ;
w, Spermatheca (or an accessory gland) ; x, Retractile ovipositor ; y, Cercus ;
z, Labrum,

beetle is thrown off, it is, in fact, the imago that is revealed. The
form thus displayed, though colourless and soft, is that of the
perfect insect ; what remains to be done is a little shrinking of
some parts and expansion of others, the development of the
colour, and the hardening of certain parts. The colour appears
quite gradually and in regular course, the eyes being usually the

184

PERIPATUS, MYRIAPODS, AND INSECTS.

first parts to darken. After the colouration is more or less per-
fected— according to the species — a delicate peUicle is shed or
rubbed off, and the bee or beede assumes its final form, though
usually it does not become active till after a further period of
repose.

The remaining chapters treat of Classification, in which the
various classes up to the Hymenoptera are very fully described
and figured. Chapter XVI., from which we have selected our last
illustration, is devoted to the Termitid^ — White Ants or Termites.
This chapter is throughout an exceedingly interesting one. Our
space will only allow of one short extract : —

The economy of Termes lucifugus, the only European Termite
besides Calotermes flavicollis, has been studied by various obser-
vers, the most important of whom are Lespes and Grassi and

A B c

Fig. 14. — Larva and Pupa of a Bee, Xylocopa violacea.

A, Larva ; B, Pupa, ventral aspect ; C, Pupa, dorsal aspect. (After Lucas.)

Sandias. This species is more advanced in social life than Calo-
termes is, and possesses both workers and soldiers (Fig. 15, 2, 3).
The individuals are much smaller than those of Colotermes.
Burrows are made in wood of various kinds, furniture being some-
times attacked. Besides making excavations, this species builds
galleries, so that it can move from one object to another without
being exposed ; it being a rule — subject to certain exceptions —
that Termites will not expose themselves in the outer air. This is
probably due, not only to the necessity for protection against ene-
mies, but also to the fact that they cannot bear a dry atmosphere ;

PERIPATUS, MYRIAPODS, AND INSECTS.

185

if exposed to a drying air, they speedily succumb. Occasionally,
specimens may be seen at large ; Grassi considers them to be
merely explorers. Owing to the extent of the colonies, it is diffi-
cult to estimate with accuracy the number of individuals compos-

Fig. 15. — Some of the forms of Termes lucifugus.

I, Young larva ; 2, Adult worker ; 3, Soldier ; 4, Young complementary
Queen ; 5, Older substitute Queen ; 6, Perfect winged Insect. (After Grassi.)

ing a community, but it is doubtless a great many thousands.
Grassi finds the economy of this species in Italy to be different
trom anything that has been recorded as occurring in other

186 PERIPATUS, MYRIAPODS, AND INSECTS.

species ; there is never a true royal pair. He says that during a
period of six years he has examined thousands of nests without
ever finding such a pair. In place thereof there are a consider-
able number of complementary queens — that is, females which
have not gone through the full development to perfect insects, but
have been arrested in various stages of development. Nos. 4 and
5, Fig. 15, show two of these abnormal royalties. No. 4 is com-
paratively juvenile in form, while No. 5 is an individual that has
been substituted in an orphaned nest, and is nearer to the natural
condition of perfect development. We have no information as to
whether any development goes on in these individuals after the
state of royalty is assumed, or whether the difference between
these neoteinic queens is due to the state of development they
may happen to be in when adopted as royalties. Kings are not
usually present in these Sicilian nests.

In reference to the above volume, we state with confidence
that each author has carried out his share of the work in a very
thorough and masterly manner. The remainder of the Insects
will be completed in Vol. VI. The illustrations, as will be seen
from those kindly lent to us by the publishers, are first-class, as are
also the letter-press and general get-up of the work. Our best
thanks are due to Messrs. Macmillan and Co. for the use of the
blocks and for permission to make the above extracts.

Proteids of Wheat. — Miss M. O'Brien has an exhaustive
paper in the Annals of Botany (Vol. IX., 1895, p. 171) on the
distribution of the functions of the aleurone grains in wheat. She
supports the theory of Weyl that glutin is formed by the action of
a ferment on the myosin, which is the chief proteid of wheat.
The aleurone-grains do not, in the GraminecB, present that degree
of differentiation in which the mineral matters are sharply sepa-
rated off as a globoid from the proteid constituents of the grain,
only the membrane is here differentiated. The theoretical view is
advocated of there being in flour one mother-substance which
readily undergoes hydration, giving rise to gluten. — Pharm. Journ.

[ 187 ]

Z\K IDiscovcr^ of IRontgcn: Sonic Details
of t\K Bpparatus anD OdGinal jEjperiments,*

By Hugo Muller (Berlin).

SLOWLY but uninterruptedly, in general, science proceeds.
One stone is laid upon the other, and the building grows
more and more ; but from time to time a shock as of light-
ning will shake the old, proud scientific construction, including
such discoveries as that of the rotation of the earth, of electricity,
of the spectral analysis, of the telephone, and so on. Such a
discovery was made some weeks since by a German, Prof Rontgen,
at Wurzburg. Many journalists have written about this discovery,
some with belief, some with scepticism. We are enabled to give
our readers illustrations made after Rontgen's descriptions, which
prove that he has not claimed too much. The experiments of
Rontgen were repeated in the electro-technical laboratory of the
Royal Polytechnic at Charlottenburg, Berlin, by Professor Dr.
Slaby and his assistant, Klingenberg. I assisted at these experi-
ments, and will endeavour to describe them so that anybody
possessing the necessary apparatus (which is very costly) will be
able to repeat them, and to convince himself of the wonderful
invention. The principal apparatus is an evacuated glass globe
(or Crookes' tube) of lo to 15 cm. diameter, through which a
strong electric current is sent.

A vacuum is formed in the glass globe, in the first instance, by
an air-pump with water, afterwards with mercury, as invented by
Sprengel. If the vacuum is not complete, the electric current
produces in the evacuated tube the so-called " Geisler " light,
which is visible to the human eye.

As the evacuation (exhaustion) proceeds, the light diminishes,
and, at a certain point, it totally disappears. In its place the glass
of the tube or globe becomes phosphorescent with a pale green in-
termittent light, this phenomenon being produced by the invisible

* Reprinted by kind permission of the Editor of TAe Amateur Photographer,
to whom also we tender our thanks for the use of accompanying block. — Ed.

188

THE DISCOVERY OF RONTGEN.

rays from the cathode. The phosphorescence of the glass is only a
secondary appearance produced by the cathode beams. Before
1879, Goldstein, of Berlin, and Hittorf, of Munster, observed
these beams from the cathode, but they received the name of

Crookes-light because, in a
report before the British
Association, Crookes did
not name Goldstein and
Hittorf, though he had
acknowledged their prior-
ity in the Chemical News
of the 30th of May, 1879.
The cathode rays, about
which further instruction
may be found in the
■Vj Annaleii der Physik and
Chemie, 1895-1896 (Len-
ard's observations), are
different from the X rays
of Prof. Rontgen. The
X rays, which appear only
if the vacuum is driven to
S ^ S the highest degree, are not
^ turned from their course
by an electro - magnet,
whereas the ordinary cath-
ode rays are so turned.
The cathode rays also
do not pass through the
glass of the globe, where-
as the X rays pierce the
glass, and spread in the
open air. The nature of
these Rontgen rays is not
yet quite known ; one
Fig. 16. would be inclined to be-

lieve that they are ultra-violet light, but that they are not refran-
gible. The lens or the prism has no influence on the X rays ; they

THE DISCOVERY OF RONTGEN. 189

pierce all materials in some way — organic tissue, flesh, wood,
paper, and so on ; therefore we suppose that the question here is
of longitudinal vibrations of the ether, whereas our ordinary light
consists of transverse vibrations. By chance, Rontgen observed
that the X beams made an impression on a photographic plate.
We may not think that the visible green phosphorescent light
produces this effect, for though the glass globe was enveloped in
a black opaque substance, so that no visible light pierced the
cover, an impression was nevertheless made on the sensitive plate.
The experiments which should prove all these miraculous qualities
of the X beams were quite recently made in the Polytechnic
School at Charlottenburg, and daylight was excluded from the
laboratory only while the sensitive photographic plate was being
put in the dark slide. Eight to twelve great accumulators of two
volts tension each were connected with a s-trong induction appara-
tus (Ruhmkorff), giving sparks of 30 cm. length. Copper wires
conducted the electric current to the electrodes of the glass globe,
which were kept joined to the mercurial air pump, to continue the
exhaustion of the air during the experiments. It seems the qual-
ity of the glass influences the success of the experiments, for of a
series of globes made by the glass-blower only two proved suitable.
The ordinary evacuated (exhausted) glass globes of commerce
were not suitable, probably because the vacuum was not sufficiently
complete. The right degree of evacuation of the air, the pressure
of which must not exceed a thousandth part of the atmospherical
pressure, is one of the necessary conditions.

During the exhaustion of the glass globe a photographic plate
was put into the dark-slide in a dark-room. It is best to use a
dark-slide made of pasteboard, because the metallic parts of a
wooden one absorb the rays coming from the glass globe. The
object to be photographed was tied on the closed dark-slide by
silken threads, and placed with it in front of the glass tube. If we
wished to make an image of our hand, we placed the dark-slide
containing the plate in front of the glass globe at a distance of
25 cm., and put the hand on the pasteboard, no lens or photo-
graphic camera being used. An exposure of 25 minutes was
sufficient. If the distance is greater, the exposure must be longer,
as the X rays diminish with the quadrate (square) of the distance.

190 THE DISCOVERY OF RONTGEN.

The plate was developed with metol and hydroquinone, and
showed an exact photograph copy of the skeleton of the hand, on
the middle finger of which we clearly saw a ring, which the rays
(though passing through the flesh of the hand and the pasteboard)
had not pierced. The ring was a band of lead, the ends of which
were not quite joined. A mouse was photographed in the same
way without removing the hair or the skin. The invisible X rays
produced an admirable image, showing all the small bones of the
body, as well as the vertebrae of the tail. In order to see in what
degree different materials were penetrable, we fastened a piece of
metal, a piece of glass, and a lead pencil on the surface of the
dark-slide, and were astonished to find that the glass absorbed the
rays as much as the metal and the graphite in the pencil, the wood
of the latter being pierced without difficulty. We also placed a
book of ICO and more pages in the way of the invisible beams,
but it was no hindrance. Finally, photographs were taken of a
hen's leg and a pigeon, requiring exposures of an hour or more.

The experiments were not without danger, because of the
strong electric currents, but were successful, not only in the labor-
atory of the Polytechnic, but also in that of the Urania (popular
physical institute in Berlin) and of the Physical States Laboratory
at Hamburg. In the laboratory of the Polytechnic we were suc-
cessful in modifying the proceedings so that the exposures were
shorter and the images more distinct.

By this new discovery science in general, but especially medi-
cine, will benefit. If, for instance, a ball has entered into a
soldier's leg, its place and the injury to the bone will be easily
found by the X rays. We need only place the closed dark-slide
(with the gelatine plate) under the injured leg, and send the X
rays from the glass globe through it ; the bone and the ball will
then appear as silhouettes on the photographic plate. Practical
results have recently been obtained in some hospitals. A young
lady had been unable, from some unknown cause, to use her right
hand for a long time. A photograph of her hand was made, and
the negative showed a white spot caused by a piece of glass through
which the X rays had not passed, and which was removed by a
simple operation. When the invention is perfected we shall be

THE DISCOVERY OF RONTGEN. 191

able to find gall-stones and other injurious bodies whose discovery
is, at present, attended with great difficulty.

The following observations help to explain how the image on
the sensative gelatine plate is produced. Rontgen observed that
even when he enclosed the vacuum tube in a dark box of paste-
board, a screen overlaid with barium cyanide of platinum began
to phosphoresce as soon as the elecric current passed through the
tube. The astonishing phenomenon that invisible rays producing
phosphorescence passed through the black pasteboard box, induced
Rontgen to try other materials, and he found that certain salts of
lime, mineral salt, ordinary glass, also phosphoresced. It is there-
fore probable that the photographic image on the plate is produced
by the phosphorescence of the glass, or perhaps, of the gelatine,
which flames up the more vivaciously the more the object before
the dark-slide, which lets pass the X rays, is penetrable.

Professor Conrad Rontgen was born at Lennep, March 27th,
1845. ^^ December, 1870, he became assistant at the Physical
Institute of Wurzburg, where he remained till May, 1872, and then
went as assistant to the Physical Institute of Strassburg. A year
after he was appointed professor at the Academy of Hohenheim.
In 1876 we find him at Giessen, and in 1888 he became director
of the Physical Institute of the University of Wurzburg. He has
published many scientific essays, which are the results of much
study and research.

When the Emperor William II. heard of this important dis-
covery he ordered Rontgen to come to Berlin, where he performed
his experiments before His Majesty, who presented him with a high
decoration (Krunenorden) for the great service he had rendered to
science, the full results of which cannot yet be ascertained.

Good Liquid Cement. — The following is said to make an
excellent liquid cement : — To a solution of chloral hydrate in
water dissolve gelatine to the required consistency. The cement
thus made is said to have great adhesiveness and to remain indefi-
nitely unchanged. Ordinary glue may be used instead of the
more expensive gelatine ; it is equally strong.

[ 192 ]

Sdcctcb 1Klotc6 from tbe ipoetal fiDicro=*
scopical Socict^'6 1Rote^Boo[^0.

Plate IX.

Diatoms. — I send this box out with great dififidence. Special-
ists are often tabooed and boxes of their slides set aside. But as
some of our members have, in the " Notes," asked me to circulate
some Diatoms, I have ventured to do so. These may turn the
serious attention of some to this most fascinating study ; if they
do, I shall be more than repaid.

Diatoms are " unicellular Algag," having a vegetable structure,
which has the power of secreting the liquid silica which comes
down from the mountains or stony plains through the rivers into
the sea, and depositing it in themselves. These valves appear
usually to consist of two or more layers, marked with the most
exquisite lines or points. They have been called " Brittle-worts,"
from their tendency to break up into fragmentary frustules ; this is
also the meaning of their Greek name, " Diatom." Their func-
tion is to suck out the carbonic acid there is in the water, using the
carbon -for themselves, and setting free the oxygen. By secreting
the liquid silica, they make the water purer and more useful.

They exist, and have existed, in countless millions ; in some
parts even the ice is made brown by the quantity of diatoms thrown
upon it ; they are found in fresh water, brackish water, and sea
water, in marls, in dried-up lakes, and in sedimentary rocks.
Though so small, they are of every conceivable shape, with striae
that run to 130,000 to the inch, as in Amphipleiira pellucida
Upwards of 4,000 forms have already been catalogued. They are
found in strata dozens of miles in length, and often many feet in
thickness ; indeed, a deposit of diatomaceous earth was found in
Victoria Land 400 miles long by 120 wide. The Columbia river
runs through two precipices, 500 ft. high, almost entirely diatoma-
ceous. The " Polishing Slate " of Bohemia, " Turkey Stone,"
and " Rotten Stone," are chiefly composed of diatoms. " Kiesel-
guhr," used for dynamite, and " Sozodont " tooth powder are
mainly diatomaceous. The famous Oamaru deposit in New Zea-
land is more than two miles in length ; near its southern end it

SELECTED NOTES. 193

may be about five feet thick ; towards the north end it is over
twenty feet thick.

It is obvious that out of hundreds of slides I can only send
round a few specimens. These shall be chosen so as to show
those who know little about diatoms their extreme beauty, both as
separate mountings, and as " spread " slides ; the latter will show
how the various forms are commingled. A few " test" slides will
also be added for those who possess " high powers."

I need hardly add that those who want to see Diatoms in their
native beauty with their endochrome should not fail to get some
diatomaceous material from some sluggish stream or marine marsh,
and look at them in a drop or two of water on a slide with a
cover-glass over, and view them with a j4-\nch objective as they
move — vegetables moving ! — they will have a treat.

If these slides convey to many of our members the same
pleasure that for years they have done to me — an old clergyman
in weak health — I shall be well repaid. They have been obtained
from various sources, mainly from my old friends, E. Grove, Esq.,
and Major Lang. The former is well known for his Paper on the
" Oamaru Deposit " ; the latter as one of the most splendid
mounters of "separate" forms. Some of the slides require at
least ^-inch objective.

Many persons give the whole of their leisure to the study of
Diatoms ; therefore, though they may be little known to some of
our members, those who have taken up the study must be borne
with if they say that they find in it a great satisfaction.

When one thinks of the prodigality of beauty that is around
us, and which no eye of man perceives, one sees an inner meaning
in the words of Rev. iv. ii — "For T/iy pleasure they are, and
were created."

Description of Slides.

Heliopelta (Sun Shield). — This is one of the class Actinop-
tychus, and one of the most beautiful of the discoid forms. The
structure of the valve appears to consist of an inferior layer, con-
taining large cavities or areolse, which on the elevated compart-
ments of the valve present the appearance of hexagonal cells, and
in the intervening compartments, of irregular circular cells ; and of

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. n

194 SELECTED NOTES FROM

a superior layer, covered with fine lines of dots, crossing each
other diagonally at a distance apart of about i /30,000th of an inch.
The central part and the small marginal spaces at the ends of the
radial lines appear to be of solid silex, destitute of markings.
The radial divisions range from six to twelve. See Carpenter's
'Microscope, 6th edition, p. 350, and PI. I.

Aulacodiscus orientalis.— Another of the beautiful discoid
forms, so called from having " furrows " running from the centre
to the margin, at the end of which come i7iflated tubercular pro-
cesses, varying in number.

Triceratium formosum. — The Trtceratia slxq z\?,o another very
beautiful class of very varied form ; sometimes they are square,
not triangular. The projections at the edges are prolonged in
some species into horns ; in others, they are tubercular elevations.

Pleurosigma formosum.— One of the most elegant of Diatoms,
The Pleurosigma are separated from the genus Navicula in having
a lateral sigmoid curvature. The strise by which the valves are
adorned range from 20,000 to 100,000 to the inch. Pleurosigma
formosum is said to have 37,000 for the transverse and 30,000 for
the diagonal markings. These are clearly seen by a ^-inch
objective.

Oamaru Selection.*-This slide contains the following : — Aulaco-
discus margaritaceus, var. Debyi ; Triceratium Nova Zealandicum ;
Stephanopysis valida ; Biddulphia Tuomeyii ; Triceratium glanda-
rium ; Triceratium majus ; Triceratium Nova Zealandicum ; Kit-
tonia elaborata — this last is one of the special forms of Oamaru
deposit.

Kiver Lea, Freshwater Deposit.— Some of the leading forms
are : — Epithemia gibba, turgida ; Navicula gracilis, limosa ; Nitz-
sckia angustata, linearis, sigmoidea ; Pinnularia nobilis, viridis ;
Pleurosigma attenuatum (abundant), acuminatum, Spencerii ; Stau-
roneis Smithii (rare) ; Surirella biseriata bi/rons ; Coscinodiscus
lineatus, an intruder. These intrusions can scarcely be avoided,

* We enumerate the principal diatoms seen on these slides to show what
forms are usually found in the various deposits. — Ed.

THE society's NOTE -BOOKS. 195

Berg-mehl (Mountain meal, Norway).— Said to be the meal
with which peasants in times of scarcity sitisfy their hunger when
mingled with their flour. Pinmdaria nobilis (abundant); Pinnii-
laria diverge/is ; Eunotia ; Gomphonema ; Stauro7ieis.

Holies Cliff, Virginia. — This is one of the finest Virginia series.
It contains Cosclnodiscus asieromphalus, apiciilatus, per/or atiis,
craspedodisciis ; Actinocydus Ehrenbergii ; Adinoptychus omphalo-
pelta ; Triceratium undulation. The Afitinocydi are generally
iridescent, with low powers.

"Challenger" Expedition Dredgings, 1950 fathoms. — This
slide is most interesting, as showing how the strata at the bottom
of the sea are still being formed. Though much is Radiolarian
ooze, still, a portion is Diatomaceous. Some of the forms are very
prevalent, Cosdnodiscus lentiginosus having a little " fleck " on the
margin, having a bit of Fragilaria Aniardica lying upon it, the
" fleck " showing a little below, common ; Cosdfiodiscus Africanus,
var. Wallidiiana ; Cose, adinodiilus ; Adinocydus Oliverianus,
common ; Fragilaria Aniardica, very common.

Sponge Sand.— This sHde shows how diatoms prevail every-
where. They were taken out of some common sponge sand,
which can be got from any chemist. The following is a list :—
Auliscus ccelatus ; A. coelatus, var. mergetis ; Navicula crabro ;
Endidya oceatlica ., covcvvixox^; Cerataulus Smithii ; Navicula lyra ;
N. Lesinensis ; Campy lodiscus limbatus ; Navicula quadriseriata.

Ananino Polishing Paste (Syzran, Simbirsk, Russia). — Some
of these forms are very striking, especially the Adinoptychi, Aula-
codisci, and Triceratia. The following are on this slide : — Adi-
noptychus heterostrophus ; Adin. Simbirskianus , Adin. sedudilis ;
Aulacodiscus quadra?is ; Aula, proba bills ; Triceratium IVeissii ;
Cheloniodiscus Anafiinetisis.

Oamaru Deposit.— This is the well-known New Zealand deposit,
so carefully described by Messrs. Grove and Sturt in the Quekett
Journal, 1884 — 1889. It forms a most interesting study, as so
many of the forms are peculiar. Amongst them are : —

Rutilaria radiata, with zone ; Cosclnodiscus spiniferus ; Tricera-
tium coscinoides ; Trie, unguiculatmn ; Navicula sparsi-pundata ;

196 SELECTED NOTES FROM

Asterolatnpra decora ; Trinacria vetitricosa ; Triceratimn plenum ;
Aulacodisciis crux. A. Clarke-Smith.

The fact that the " PoHshing Stone of Bohemia," mentioned
by Mr. Smith, is chiefly composed of Diatoms, is rather suggestive
to microscopists of what happens to people's teeth when they use
" Sozodont."

Is it true that P. Formosum ever possesses " striae " or any
other markings of the extreme tenuity of 130,000 to the inch ? I
studied them for some years hopefully in search of the solution to
the markings because they were so large. Carpenter mentions
them as tests for low powers. But it is to be much desired that
Mr. Clarke-Smith had given us some specimens of what would be
something more than that. No wonder my old friend is such an
enthusiast on Diatoms when he has such friends to send him
information on the latest and choicest gems.

I cannot say all my enthusiasm survives. I greatly admire
them, but cannot help thinking there is a lot of waste time spent
over classification. I believe there will come a time when that
will be abandoned and a simpler process substituted for the more
laborious one.

I entirely endorse what my friend suggests. Get them living
out of the dykes and highways for yourself, and direcdy you get
home set to work, and see them move with your own eyes. It will
be an eye-opener on the subject of the movement of Vegetables!
However, some seem so sure about it that I suppose there is no
more to be said. Still, I notice that Mr. A. Smith has doubts on the
point ; but I know that his views on the subject are expressed in his
second paragraph. For myself there is left no alternative but to
come to the conclusion that some sort of vegetables, especially in
the lower grades of life, have the appearance of being very
knowing things.

As to the beauty of the forms, it has always seemed to me that
Practical Astronomy has in some way its analogue in the micro-
scopical study of diatoms. I also hope we shall have a further
selection at some future time from Mr. Clarke-Smith's cabinet.

Lionel Bartleet,

THE society's NOTE-BOOKS. 197

Mr. Bartleet has misunderstood what I said about markings.
I did not say that Pleurosigma fonnosiim had markings uj) to
130,000, but that some had. I have, however, at Mr. Groves'
suggestion, altered my statement, making them to run up to
1 00, 000th of an inch, Amphipleura pellucida 93,000 ; Navicula
subiilissitna \\2ls 112,000. A. Clarke-Smith.

Having lately spent a good deal of time upon diatoms, the
present box of slides presents to me great interest. To draw
diatoms would be labour of love and infinite patience. A much
more ready way is to photograph them, and no structures lend
themselves more readily to the process than diatoms. A photo-
graph of Coscinodiscjis shows the areolated appearance of this
diatom, as seen with the 34^-inch objective. The appearance thus
shown is called primary structure, and to those not accustomed to
examine diatoms it would seem unnecessary to examine such a
diatom with the higher power. Another photograph shows a
portion of the same diatom made under a i/i2th oil immersion
lens. The diatom frustule is slightly arched on the surface, so
there is only a portion of it can be brought into focus at one time
with such a high power. The centre or peripheral portions are
therefore out of focus, the median zone being more or less in
focus. In this portion other structures are shown. Around the
primary areolatures are seen secondary areolations, and in the
centre of the primary areolations the appearance of structure which
under the magnifying power (950 to 1000 diameters) cannot be
adequately defined. With the latest apochromatic objectives of
Zeiss, giving a magnifying power of 2000 to 3000 diameters, the
structure in the centre of the primary areolations is shown to be
an exceedingly fine cribriform plate. These secondary areolations
and cribriform plates are often spoken of as the " ultimate struc-
ture " of the diatom. But who shall say that this is ultimate
structure ? This can only be decided when lenses have been pro-
duced possessing over those which we have at present in our
possession, still wider angles and proportionate power.

I enclose also a photo of a well-arranged group of diatoms * in
my possession, as seen by a dark-ground illumination. Besides

*We regret that we cannot reproduce these photographs.

198 SELECTED NOTES FROM

diatoms, it contains plates of Synapta and wheels of Chirodota
violacea. It is an extremely pretty object when viewed under the
microscope, many of the diatoms being iridescent. Some may
look upon such a production as waste of time. If of no further
use, it stands as a testimony to a wonderful amount of patience,
labour, and dexterity. I introduce it to show what may be done
with diatoms by enthusiastic diatomists. J. R. L. Dixon.

Diatomaceous Material, To Treat.— Mr. Allen has asked me to
give my method of treating Diatomaceous Rock, such as Oamaru,
etc. 1 give that which Mr. Grove (of Oamaru renown) has given
me. It may not prove of much use to our advanced manipu-
lators, but it may be useful to those who are beginning to work
among Diatoms — that most fascinating study.

Break up the rock with a knife (or otherwise) into thin slices.
Get a little sulphate of soda (Glauber's salts), and cover some of
the slices with the salt heaped up, in a small evaporating dish ;
sprmkle over it a very few drops of water; heat over a lamp till
the salt melts. Take away the lamp and let it all crystallise ; if it
does not, drop on a dry crystal, and it instantly will do so. When
cool, put in a little water and warm again, and if it does not fall
into pieces evaporate the water, and let it crystallise again ; then
wash well and boil in sulphuric acid, etc., as usual. After good
washing, boil again with a very small bit of caustic potash for two
minutes only, and then pour into dilute muriatic acid. It should
then be clean. In lieu of an evaporating dish, the top of a cocoa-
tin may be used, and the whole put on the bars of the fire-grate.

Decanting. — It is here that the trouble begins. Get some
small beakers about an inch and a-half in diameter and three
inches deep. If there is coarse, heavy sand, give half a minute
eacli time to settle. Do not pour off too closely at first, and after
two or three decantings you will be able to pour off clear. When
the water becomes quite clear, stop and examine the sand to see if
there are any large diatoms in it. If not, throw it away, and
when the decanted stuff is quite settled down in the large vessel,
into which you have poured your decantings, pour off all the water
you can without disturbing the bottom, and then giving the vessel
a good shake, pour the sediment back into the small beaker, and
repeat the decanting process at two minutes' interval. Proceed as

( THE society's note-books. 199

before, and then decant again at five minutes ; and if the diatoms
are very small, at ten minutes. The dealers prepare large quanti-
ties at a time. They get rid of the coarse sand by " rotating,"
and of the light sand by filtering through fine gauze. The great
point is to have the stuff properly cleaned before decanting and
rotating, so that you have clean sand and cleaji diatoms. But you
cannot get such stuff as Oamaru clean and bright with acid only.
It must be boiled up afterwards with alkali, either carbonate (in
which case you must boil it for a considerable time), or caustic (in
which case you must use a very small piece and only boil for a
minute or two) ; but the material must be bright and clean before
you can separate -densities properly. Should the flocculent matter
not disappear, try the Liquor Ammonia process. Pour off the
water from the deposit closely, put about half-an-inch o( Afmnonia
fortissimum into it, shake it well, leave it standing for a day or two
(at least twenty-four hours), dilute it well with water, and then pour
in enough muriatic acid to neutralise the ammonia. Shake vigor-
ously before decanting several times in distilled water. — —Another
plan. — After washing away the sulphuric acid, boil with common
soda, and then while still hot neutralise with muriatic acid ; wash
and repeat the boiling with soda, etc., until all the flocculent
matter has disappeared. It should then be well shaken in a
bottle and decanted as before. But, oh, the patience required for
this work !

By the courtesy of our Hon. Secretary, I am able to add some
additional Notes, taken from my second Box of Slides.

Therein I endeavoured to show that we must no longer arrange
diatoms by their shapes ; that increase of knowledge brings increase
of accuracy. I illustrated this by the genus Stictodiscus. Formerly
Triceratium parallelum was arranged in the genus Triceratium.
It is now removed from that class, and is put under Stictodiscus,
which now assumes either a discoidal, or triangular^ or quadran-
gular form. Hence, Stictodiscus Californiciis may be S. Californi-
ciis, discoidal form ; or S. C. forma trigona ; or 6". C. forma trigona,
var. gibbosa ; or S.C. forma quadrata. The other discoidal forms
were S. C, var. areolata, S. Hardmanianus, and S. fiitidus. I may
add the description of these as then sent.

Stictodiscus Californicus has large puncta somewhat remotely

200 SELECTED NOTES FROM

scattered around the centre of the disc, and then passing in rays
of single puncta to the margin, near to which there is often a
double row. Sometimes the puncta at the centre are more clearly
aggregated. The typical form is to be found in any of the
Californian deposits.

S. Calif., var. areolala, has a secondary set of areolate or
reticulate markings, which appear in focussing down a little.

S. Hardtnatiianus. — The radiating compartments are very
numerous, and the rays towards the outside consist of five or six
rows of minute granules, and round the centre are usually one or
two circles of small granules ; the puncta are not so large and the
hnes between are longer.

6". nitidus is dotted over sparsely with large shining puncta,
giving it a brilliant appearance. A. Clarke-Smith.

Description of Plate IX. Stictodiscus.

No. 1. — S. Calif ornicus.

No. 2. — S. jjarallelus f, triguna.

No. 3. — S. parallehis f. trigona, v. gibbosa.

No. 4. — S. parallelusf. quadrata.

Breeze Fly, Foot of.— The " Foot of the Fly "' is a subject to
reason upon from analogy, as it is so small an object, and a fly's
walking is so impossible to observe that I do not see how it can
be " settled " positively either way.

The Breeze-Fly, Tabanus Bovinus, is one of the Gad Flies.
This family has three pads to their feet. I think some other flies
have also, but am not sure. I certainly believe the ends of the
hairs on the skinny pad are all " hooked." I do not see the
expansion at the end, except when the end is out of focus. I can
quite believe in a viscid fluid to help to make the vacuum secure,
but I cannot think that enough is poured out to stick the fly's foot
to the glass, and that then the fly can wrench the feet away quickly
enough to walk as it does. I allow that the adhesion in a vacuum
is a strong argument against the sucker theory, but a real vacuum
is very difiicult to get, and a very partial one would support a fly,
I think. Then old flies (or, rather, weakly onesj might have their
feet stuck to the glass by the fluid and not be able to take them
up, though they use a sucker generally.

JoumaJ of Microscopy, 3" Ser. Vol. 6, Plate 9.

Diouto

rrfy^.

F.Phillips Sc.

THE society's NOTE-BOOKS. 201

Gosse, in hi.s Natural History of Reptiles, speaks of the Ghecko
lizard, and on p. 86 describes the structure of the under side of
the toes as enabling them to cling to inverted surfaces as House
flies do. He says : — " The mode in which this is effected we do
not thoroughly understand ; but we may conjecture that it is by
the raising of these imbricated plates by muscular action, so as to
form a vacuum beneath the sole, when the pressure of the external
air causes the toe to adhere firmly to the surface." Gosse uses
the leather sucker a few lines further on as an illustration. The
Ghecko can, when alarmed, move very fast. *

I do not profess to see hooks on the hairs of all fly's pads ;
they are not so easily to be seen on the Blow-fl3''s foot. I consider
the foot of the Breeze-fly as one of the best examples of "hooked
hairs " on the pads. I believe the Drone-fly and the Dung-fly
have straight hairs. The Ophion-fly has no hairs at all, I think.
The pad appears quite bare of them, and I think the pad of the
Wasp's foot is without hairs, and if so they cannot adhere by
means of a fluid poured out of expansions at the end of hairs.

W. LOCOCK.

I have carefully examined this slide with i/i2th o.g., and
cannot satisfy myself as to there being a single hooked hair. The
appearance is, in my opinion, due to the bulbous or blunted end
of the hair from which the viscid fluid is exuded, and the action
of reflected light in the lumen of the hair gives a hooked resem-
blance when the object is out of focus. I have observed the same
hooked appearance in some vegetable hairs, which poured out an
adhesive or sticky substance. R. S. Hudson.

I cannot imagine what use hooked hairs would be if they
exist to a fly in walking upon glass, as we cannot detect any
irregularities on ordinary glass slips, even with high povi^ers. To
be of any use these hooked hairs must catch in some irregularities,
and not only catch, but must also hook around the irregularity to
be of any service. Compare the relative proportions of the foot-
pad hooks and the glass to an ordinary black beetle and a sheet of
paper. Although the beetle can climb up a white-washed wall, a
papered or painted wall puzzles him, and in the cockroach the
hooked claws are assisted by spurs on the elbows. From the

202 SELECTED NOTES FROM

above I should think the vacuum theory the most tenable. I
believe the hairs are curved at their extremities, as one frequently
finds in the case with all slender filaments ; but I cannot think
those curved hairs would be sutificiently stiff to act as hooks.
Some time since 1 examined the parasite of the House-fly alive,
and think I sent a sketch showing the vacuum producing arrange-
ments in their feet. In their case the movement of attachment
and detachment was instantaneous, and I could not discover any
sign of a gummy matter on the glass. If a gummy substance were
used to assist the walking of a fly, we might hope to find foot-
prints on polished glass. I have, however, never heard of this
discovery. T. R. Barrett.

I have examined the slide, "Foot of Breeze Fly," with i/i6th
immersion o.g., and am satisfied that some, but not all, of the
hairs are curved towards the extremity, but whether sufficiently to
be of service in grasping irregularities, I am not able to give an
opinion. I'he tubular character of the individual hairs can
clearly be made out. Annie Pennington.

I think these hairs are well seen with a low-angled ^-in. o.g.,
especially on a dark ground ; there are no " hooks," the hairs are
slightly curved, but apparently only sufficient to make the ends
perpendicular to the surface walked on ; the ends appear as blunt
as if cut off with a sharp instrument. This class of object is
seen better when prepared in glycerine. Balsam renders them
too indistinct. R. Smith.

The why and wherefore a fly clings to polished surfaces, such
as glass, is a subject very much unsettled, and yet high authorities
seem to agree somewhat. Dr. Carpenter says : — " The foot is
furnished with a pair of membranous expansions termed pulvilli.
These are beset with numerous hairs, each of which has a minute
disc at its extremity. This structure is evidently connected with
the power which these insects have of walking over smooth sur-
faces in opposition to force of gravity, yet there is considerable
uncertainty as to the precise mode in which it ministers to this
faculty. Some believe that the discs act as suckers, the insect
being held up by the pressure of air against their upper surface
when a vacuum is formed beneath ; whilst others maintain that

THE society's NOTE-BOOKS. 203

the adhesion is the result of the secretion of a viscid Uquid from
the underside of the foot. Careful observations by Mr. Hepworth
{Quarterly Journ. Micro. Set.) have led him to a conclusion whieh
seems in harmony ivith all the fads of the case — namely, that each
hair is a tube conveying a liquid from a glandular sacculus situated
in the tarsus, and that when the disc is applied to a surface, the
pouring forth of this liquid serves to make the adhesion perfect.
That this adhesion is not produced by atmospheric pressure alone
\% proved by the fact that the feet of files continue to hold on to the
interior of an exhausted receiver; whilst, on the other hand, 'that
the feet pour forth a secreted fluid, is evidenced by the marks left
by their attachmefit on a clean su?face of glass." Mr. Barrett (p. 201)
seems never to have heard of this. Dr. Carpenter continues : —
"Although when all the hairs have the strain put upon them
equally, the adhesion of their discs suffices to support the insect,
yet each row may be detached separated by the gradual raising of
the tarsus and pulvilli, as when we remove a piece of adhesive
plaster by lifting it from the edge or corners. Flies are often
found adherent to window-panes in the autumn, their reduced
strength not being sufficient to enable them to detach their tarsi."

Hogg also says : — " The delicacy of the structure of these
hairs in the fly, the bend near this extremity, in each of which
supervenes an elastic membranous expansion, and from which a
very minute quantity of clear transparent fluid is emitted when the
fly is actively moving, explains its capacity for clinging to polished
surfaces."

And, again, who has not read Rev. J. G. Wood's Cotjwioji
Objects of the Microscope ? This is what he says : — •" The organ
is seen under a very high power to be covered with hair-like
appendages, each having a little disc at the end, and probably
secreting some glutinous fluid which e?iables the creature to hold on to
perpendicular and smooth surfaces. Many of my readers will
doubtlessly have noticed the common fly towards the end of
autumn walking stiffly upon the walls and evidently detaching
each foot with great difficulty, age and infirmity having made the
insect unable to lift its feet with the requisite force." — F. C. Cox.

I think the question of how the flies walk has been ventilated
before in our Note-Books. In addition to the authorities quoted

201 SELECTED NOTES FROM

by Mr. Cox, Mr. Lowne also expresses the same view — viz., that
adhesion is effected by means of a viscid fluid poured out from
the hairs, and states * that the foot-prints left upon glass by the
house-fly consists of rows of dots corresponding to the hairs.

He describes, moreover, the sac which secretes this viscid
fluid, which, he says, fills the whole of the last four tarsal joints.
He has also described this sac in Dytiscus, but I cannot at the
moment refer to it. I certainly cannot see hooks in the slide sent
by Mr. Locock, but bulbous tipped hairs. A. Hammond.

Boring Sponges.— I'liese were taken from an oyster-shell. The
oyster has many foes to contend with, and hundreds of them are
destroyed by the boring sponges, which riddle the shells with
holes and then live on their victims. This was certainly the case
with the oyster from which these objects were taken, for the shell
was bored through and through, and when opened contained
nothing but mud, the poor oyster having met with an untimely
end. M. A. Henty.

Oyster shells perforated with holes drilled by these Clione
are often to be seen at the fishmonger's. When examined
fresh, with a good pocket-lens, these shells will be seen to be
coated and lined with a yellowish substance, which forms part of
the Cliona or Boring sponge. How it excavates these holes and
cavities is a mystery; but it seems to have the power of dissolving
away the lime for the purpose of living on the animal matter con-
tained in the shell. The holes are generally of two sizes — the
larger for the emission of oscular tubes ; the smaller, which are
much more numerous, for the poriferous tubes. On splitting the
shell open, both are found to communicate with irregularly sunken
canals, occupied by the yellowish coloured body of the sponge.

To obtain a good collection of the spicules, boil this yellow-
looking substance in dilute nitric acid, and abundance of spicules
will be found. No doubt the animal uses these in its borings. If
the oyster fresh from the sea be placed in a vessel of cool sea-
water, delicate mobile tubes will be seen protruding from the
various apertures. Those from the larger holes end m a single
oscular opening; those from the smaller expand at the end into a

* Lowne's Anatomy of the Blow- Fly ^ p. 21.

THE society's NOTE-BOOKS. 205

conical form resembling the rose of a watering-pot, only that the
margin is fringed with a corona of delicate diverging spicules.
The tubes are very sensitive to touch and light. They instantly
contract and withdraw themselves when exposed to powerful sun-
light. Currents of water flow into the poriferous tubes and out of
the oscular tubes. In autumn this sponge mass will be found
crowded with ciliated embryos, about i/2oth of an inch long, with
spicules already developed in them. These Cliones are also found
in a fossil state in the shells of the Silurian strata, where we find
Belemnites perforated by them in a similar manner to the recent
oyster. Miss Henty's slide shows the spicules well with a high
power. E. E. Jarrett.

This slide is a happy variation from the usual run of slides,
and Miss Jarrett's note adds greatly to the interest of it.

The process by which such soft, helpless-looking creatures as
these tiny sponges are able to perforate hard shells, and even lime-
stone rocks, is so obscure and so difificult of explanation, that some
naturalists — and Dr. Bowerbank among them — have been led to
deny the possibility of the thing. They hold that these borings
are the work of marine annelids, and that the sponges afterwards
appropriate them for purposes of protection and concealment, and
live there as parasites upon the shell. But the balance of evidence
seems to be in favour of the Sponges making the holes as well as
living in them. Those who care to go into the subject will find it
somewhat fully discussed in Quekett Journal, No. 47, July, 1881.

J. H. Green.

Although the question as to whether the sponge does the
boring for itself is fully discussed in the number referred to of the
Quekett Journal, the matter is not settled. I think there is much
probability in the view that the sponge itself excavates the hole it
occupies. How it does so is another question which Mr. Waller,
the writer in the Quekett Jour 7ial, does not attempt to settle.

Geo. U. Brown.

Can the boring be effected by evolution of carbonic acid from
the sponge, dissolving away the carbonate of lime of the shell ?
Some of the lichens ( Verrucaria) in some such manner sink their
shields deeply into the limestone rock on which they grow.

206 SELECTED NOTES FROM

Miss Jarrett must be in error about boring-sponges being found
in Silurian Belemnites. The Belemnite is not a shell, but an
internal skeleton, and the Belemnitidse do not make their appear-
ance in geological time until long after the Silurian period, begin-
ning and ending, in fact, with the Secondary. H. F. Parsons.

Black Background for Mounting Specimens— While using Dr.
Dudgeon's pocket Sphygmograph, 1 was greatly struck by the
good background produced by holding enamelled paper over the
flame of burning camphor until it became coated with soot.

The tracings of the needle were also very white and well
defined. This led me to think that it might be applicable for
opaque mounting, and peculiarly suited for mounting many species
in numbered spaces on our slide. I tried it and found it to work
very well. The following is the process I have found most suc-
cessful : — The paper is first gummed to a slip of thin card, and
after it is dry held over the flame of burning camphor until the
surface is evenly coated.

I found it tedious to rule each line separately, so I hit on a
plan which has proved very successful. I took a paper of pins,
and after selecting an even row I gummed it to a glass slip, and
fixed a handle to the other side of the slip. By this means I
could rule all the parallel lines at one stroke, and by another
stroke all the lines at right angles to these, thus dividing the slide
into equal spaces.

The spaces can then be numbered with a mounted needle. A
weak solution of shellac in spirit should then be poured over the
blackened surface and allowed to dry, when it will be found quite
fast. The specimens may then be stuck on in the ordinary way
with gum.

The gum I use is a mixture of equal parts of gum arable and
tragacanth dissolved in cold water with a little glycerine, and the
whole evaporated in a small ointment-pot and kept dry. A drop
of water placed on the surface of the gum will dissolve enough
for a slide in a few seconds. This combination neither breaks the
specimens nor lets them get loose. S. M. Malcomson.

Bryozoic Rock, Clifton.— The Bryozoa — or Moss Coral, as
they are called by some ; Cilio-branchiate Polypes by others — are

THE society's NOTE-BOOKS. 207

of a higher grade than the simpler Polypes, and form a numerous
class of their own. Ehrenberg and D'Orbigny have detected
hundreds of microscopic fossil species, and it appears that their
shells, or outer tissues, enter largely into the composition of chalk-
beds, compact mountain limestone (as in Clifton), the flints of the
Jara limestone, the Sea-sand of Europe, the Mauritius, the Sand-
wich, and other islands, and even the sand of the Libyan Desert !
Some idea of their extreme minuteness may be formed when some
levigated whiting is spread out mixed with water and placed under
the microscope, when a Mosaic work of these animalcules of varied
and beautiful forms may be seen by its means. A power of j^-in.
shows the cells in the transverse sections in the slide before us
splendidly. E. E. Jarrett.

The Bryozoa or Polyzoa are, or ought to be at least, familiar to
most of our members, the Flustra, or Sea-Mats, being an example
of the marine, and Fiumafella, etc., of the fresh water. I have
tried, but without success, to see a mosaic of beautiful forms of
Bryozoa, or indeed anything else in whiting. Are the Bryozoa
animalcules ? Perhaps this depends on what an animalcule is.

A. Hammond.

Batrachospermum, To Mount.— I have found no difficulty in
preserving Batrachospermum in glycerine by Hautzsch's method.
Hautzsch's fluid consists of a mixture of Alcohol, 3 parts ; Dis-
tilled water, 2 parts ; and Glycerine, i part. This is nearly of the
same specific gravity as water. The specimen is floated in a cell
filled with this fluid, and set by, lightly covered to keep out dust.
The spirit and water gradually evaporate and leave the glycerine
behind. In this way the water in the texture of the plant is gra-
dually replaced by glycerine, and we avoid that shrinking from
exosmosis which takes place when the specimen is suddenly
transferred from water to a dense fluid like glycerine.

H. F. Parsons.

Blood, Circulation of, To see.— Dr. C. Hiiter, a German savant,
has devised a simple arrangement which makes visible the circula-
tion of the blood in the human body. His method is as follows :

The patient's head, being fixed in a frame, on which is a con-
trivance for supporting the microscope and a lamp, his lower lip is

208 SELECTED NOTES FROM

drawn out and fixed upon the stage of the microscope by means
of clips, the inner surface being uppermost, and having a strong
light thrown upon it by a condenser. When these arrangements
are completed, all the observer has to do is to bring the micro-
scope to bear on the surface of the lip, using a low power o.g. and
focussing a small superficial vessel. At once he sees the endless
procession of the blood corpuscles through the minute capillaries,
the colourless ones appearing like white specks dotting the red
stream. Dr. Hiiter asserts that by taking careful note of varia-
tions in the blood-flow and changes in the corpuscles, he has
derived great advantage in the treatment of medical cases. This
is the first instance of the flow of the vital fluid in one person
being watched by another. T. F. Uttley.

Bacilli from Phthisis. — For an admirable paper on this, see our
yoi/rna/ (or ]u\y a.nd October, 1883, which is the best resume of
the subject I have seen. I searched the secretions in three cases
of marked phthisis in vain — no bacilli to be seen ; and then find-
ing some in other cases, it occurred to me that the former were
using antiseptic inhalations — the latter not. This does not at all
imply that the antiseptic had removed all the algal life from the

sputum. C. P. COOMBE.

1 have examined the sputa in very many cases, and, so far,
think that there is no doubt of the value of this discovery, both
as a means of diagnosis and also of prognosis. In my experience
the greater the abundance of the bacilli, the sooner will a fatal
termination of the case occur. If they are few in number, and
keep so, the patient will not become rapidly worse. J. Deans.

Bone, Human.— Griffith's text-book, p. 114, says: — "In exa-
mining a transverse section of bone, one or several large cavities
will be seen with the naked eye in the centre of the section ; these
contain the marrow or medulla. In the long bones the medullary
cavity is single, and runs longitudinally down the bone ; whilst in
the flat bones the cavities are numerous, forming cancelli. Under
the microscope, thin transverse sections of bone exhibit oval or
rounded holes, or foramina, which are sections of canals convey-
ing blood-vessels through the bone ; these are the Haversia?i canals.
Around the sections of these canals are seen numerous concentric

THE society's NOTE-BOOKS. 209

rays, indicating layers or lamellae of bony matter. The substance
of bone presents numerous black, somewhat elongated bodies,
called lacun {lacunaa^ a little hollow), or bone corpuscles, which
are, however, hollow, therefore not truly corpuscles, as they were
formerly considered. Between the adjacent lacunae run numerous
fine, dark, branched lines, consisting of very minute canals, or
canalicidi. If the section of bone be viewed by reflected light,
the lacunae and canaliculi appear white. In the dried bone they
contain air.

The structure of bone is best seen when viewed as a trans-
parent object in the dry state ; for when the section is immersed
in liquid, the lacunae and canaliculi become filled up.

T. F. Uttlev.

Bath rnMcroecopical Society.

^be Batb Matcre.

AT a recent meeting of the Bath Microscopical Society, Mr,
J. W. Morris, F.L.S., read an extremely interesting paper
on " Hazel Nuts and their Crystallised Contents found in
the course of Excavations at the Roman Baths."

Mr. Morris explained that the subject which he had to bring
before them had come to light, if he might use such an expres-
sion, in rather an accidental way. There was nothing at all novel
or strange in the fact of hazel nuts being found among the Roman
remains. They had been found from time to time for centuries
past, and there were a good many of them in the cases at the
Pump Room. The odd thing was that through these long ages
nobody ever thought of ' inquiring within upon everything,' until
the results were discovered which were being placed before them.
The frequent occurrence of the nuts was noted by Stukeley, who
in 1724 wrote as follows : — "It is remarkable that at the cleansing
of the springs, when they set down a new pump, they constantly
found great quantities of hazel nuts as in many other places among
subterraneous timber. These I doubt not to be the remains of
the famous and universal deluge, which the Hebrew historian tells

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. o

210 THE BATH WATERS.

US was in the autumn, Providence, securing by that means the
revival of the vegetable world."

A sufficiently curious comment, but still nothing like so curious
as the fact that with the nuts to hand and the microscope at their
elbow, no one had thought of looking to see what was inside them.
On one occasion, in the earlier days of the excavation, a man
came up with some of the nuts in his hand, and he (Mr. Morris)
had no sooner taken them up than he noticed something gleam
through a crack in one of them. This brought the pocket-lens
out, and then he saw that there was really something to investi-
gate. The contents proved to be various kinds of crystals, which
were not only interesting and beautiful, but were in many respects
important, as bearing testimony on one or two points in connec-
tion with the Bath mineral waters. In some cases the kernel was
found to have been converted into solid calcite ; in others it had
perished, and the shell or testa of the nut was lined with crystals-
In some instances where the nuts had been cracked, water had
infiltrated through the cracks. The water which came in poured
with it the pulverised, smashed, and crushed atoms of broken
crystals, and strewed over the projecting peaks and pinnacles of
the carbonate of lime, a perfect shower as if a snowstorm had
descended upon the Alps. A curious thing was that in the clefts
of these peaks he had found the sporangia and the scale of a fern.
Some of the nuts were filled with quartz sand just like that
preserved at the Royal Baths, and on searching through this they
found curious evidences of organic remains.

The microscope showed him a spray of Selaginella absolutely
to be identified, while close by were a number of the spines of
Echini. These must have been washed into the nut through
cracks. Projecting from the sides, or lining the testa of the nuts,
crystals of strontia were found, being readily recognisable by their
blue tinge and their radiating fan-shaped distribution. There was
also arragonite. Carbonate of lime, when mixed with a little
strontia, would frequently yield arragonite, but the latter was very
apt to fall from the surface on which it was formed as it had in the
case of one of his best specimens that evening on the way to the
Institution. They found in these crystals curious evidences of
change of temperature. In many instances a change of tempera-

THE BATH WATERS. 211

ture had caused the carbonate of lime to take the form of arrago-
nite and in others the form of calcite. The strontia crystals,
radiating and bundled like a closed fan, had a magnificent sheen
upon them, and were remarkably beautiful.

If they took the analysis of Bath waters, they would find it
stated in some of them that traces of strontia were found ; in
other instances, it would be said that traces of strontia were sus-
pected. Was it not an interesting thing, therefore, that what by
chemical analysis of the water was " suspected " or barely traced,
they could now by this natural process show as actual crystals ?

The question naturally arose how far these crystals were due to
the action of the Bath waters at different temperatures on these
nuts, either by coming through cracks or absolutely finding their
way through the pores of the shell, and how far they might be
due to the properties of the hazel nut. He was at one time half
disposed to think that he must credit the hazel with some share of
the performance, but he was rather disposed to give that theory
up, as one day he had accidentally discovered similar crystals in
the skull of a Romano-Briton at the Pump Room. Another
curious feature about these hazel nuts was that the spiral fibre was
found to have remained, although the nuts themselves had perished.
It was sufficiently perfect for the instruction of a Botany class.
The lecture also contained other points of interest, and Mr.
Morris was heartily thanked for delivering it. The specimens
exhibited by Mr. Morris were of great interest and beauty.

[ 212 ]

Practical Methods in Microscopy. By Charles H. Clark,
A.M. Cr. 8vo, pp. xiv. — -219. (London: Isbister and Co.) Price 6/-.

This is a very well arranged and useful book professedly for beginners, and
is designed to afford the means of acquiring the necessary training. The
methods described are thoroughly practical. There are many illustrations in
the text, besides several plates giving very distinct photographic reproductions
of 17 microscopic objects. In the appendix will be found a number of useful
formulae, staining fluids, mounting media, etc.

Essentials of Vegetable Pharmacognosy. By Henry H.
Rusby, M.D., and Smith E. Jellifife, M.D. Royal 8vo, pp. 149. (New York:
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A treatise on Structural Botany, designed especially for Pharmaceutical
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A Text-Book of Dynamics. By William Briggs, M. A„ LL.B.,
F.R.A.S., etc., and G. H. Bryan, M.A. Cr. 8vo, pp. 192— xiv. (London :
W. B. Clive.) Price 2/6.

In this volume of the University Tutorial Series, the use of Mathematical
FormulcE has, as far as possible, been avoided in the solution of problems and
worked examples. Considerable attention has been paid by the authors to
" average velocity" and " relative velocity." Due prominence is also given
to the metric system of units, and care is taken in all examples to point out
what units are used at each stage of the process. Many worked-out examples
will be found throughout the book.

Physical Laboratory Manual for Elementary Science
Classes. By H. N. Chute. Cr. 8vo, pp. xvii. — 218. (London : Isbister
and Co. 1896.) Price 2/6.

In this work the instructions in the manipulation of apparatus are made
unusually full, at the same time pointing out the difficulties which are most
likely to arise. Special attention is given to the important subject of tabulating
and working out results, and deriving from them their proper conclusions.
There are a number of illustrations, and we feel sure the book will prove most
helpful to the student.

A Laboratory Course of Experimental Physics, By W.
J. Loudon, B.A., and J. C. McLennan, B.A. Large 8vo, pp. viii. — 302.
(London: Macmillan and Co. 1895.) Price 8/6 net.

This contains a series of elementary experiments specially adapted for
students who have had but little acquaintance with higher mathematical methods.
These are arranged, as far as possible, in order of difficulty. The experiments
in Acoustics are simple and of such a nature that most of them can be performed
by beginners in the study of Physics. Throughout the entire work simplifica-
tion of method has been the great aim of the authors.

REVIEWS. 213

Text-Book of Elementary Biology. By H. J. Campbell,

M.D. Cr. 8vo, pp. xii. — 306. (London: Swan Sonnenschien& Co. 1895. ) 6/-
In this (the second edition) the author treats of Protoplasm, Cells, Cell-
division, Reproduction, the early stages of Development, and the massing
together of Cells to form Tissues. There are also chapters on the Vertebrata,
Invertebrata, and Plant Structure. A chapter on the Dog-fish is given as a
type of the lower Craniata. In the Appendix will be found an account of the
Spirogyra and of the Anatomy of the Earth-worm and Frog. There are 136
good illustrations in the text. —

A Contribution to our Knowledge of Seedlings. By the
Rt. Hon. Sir John Lubbock, Bart., M.P., F.R.S., D.C.L., LL.D. Cr. 8vo,
pp. vi.— 288. (London : K. Paul, Trench, Trubner, & Co. 1896.) Price 5/-

We are pleased to be able to notice a popular edition of Sir John Lubbock's
very exhaustive treatise on Seedlings, which appeared a few years ago in two
large octavo volumes. In the smaller volume before us a large amount of in-
formation is given, illustrated by 282 figures in the text.

British Moths. By J. W. Tutt, F.E.S. Cr. 8vo, pp. xii. —
368. (London: Geo. Routledge & Sons. 1896.) Price 5/-

We have much pleasure in directing the attention of our friends to Mr.
Tutt's new work. The author is the editor of The Entomologists Record. His
aim in this work is to point out to young collectors and students the present
condition of entomological science, and to make them correct and accurate
observers. There are 12 coloured plates and 60 engravings in the text. It will
be found a most useful book.

A Hand-Book to the Game Birds. By W. R. Ogilvie-Grant.
Vol. I., Cr. 8vo, pp. xvL— 394. (London : W. H. Allen & Co. 1896.) 6/-

This volume of "Allen's Naturalist's Library" describes the Sand-Grouse,
Partridges, and Pheasants, the aim of the author being to provide such a book
as will be useful to the sportsman in every part of the world ; and the present
volume will prove of service to travellers in Africa, as it gives a diagnosis
whereby every species of Francolin known up to the present time may be dis-
tinguished. Besides several engravings in the text, there are 21 nicely coloured
plates.

The Story of the Solar System, Simply Told for General
Readers. By George F. Chambers, F.R.A.S. i2mo, pp. 202.

This is one of the interesting "Story" series, and a companion volume to
the " Story of the Stars," published a short time ago. These little books con-
vey a large amount of information in a most readable form. A chapter is given
to each of the Planets, and one to Comets. There is also a useful Table of
the Solar System, and 20 illustrations.

The American Annual of Photography and Photographic
Times Almanack for 1896. 8vo, pp. 370. (New York : The Scovill and
Adams Co. 1896.) Price — in paper covers, 2/- ; boards, 4/-

This is the tenth volume of the series, and, so far as we can judge, is the
best yet issued. It contains contributions from some sixty authors and an
unusually large number of plates and other illustrations ; also, 150 Formula;
and Useful Recipes.

The Medical Annual and Practitioner's Index : A Work of
Reference for Medical Practitioners. Cr. 8vo, pp. 732. (Bristol : John
Wright and Co. London: Simpkin, Marshall, and Co. 1896.) 7/6 nett.

This important work has now reached its fourteenth Annual Volume, and
is the result of the labours of thirty-six contributors and editors, each of whom

214 REVIEWS.

treats of a special subject. As these subjects are so varied, it will be impos-
sible to name them all. Suffice it to say that the Dictionaries of New Remedies
and of New Treatment occupy important positions in the book, and as a proof
of the up-to-date character of the work, we notice a paper on Rontgen's Method
of Shadow Photography, by E. H. Fenwick. F.R.(".S., with additions by
J. W. Gifford and J. L. Thomas. There are i8 plates, many of then:i coloured,
and 72 wood engravings.

Thf, Tutorial French Grammar. By Ernest Weekley,
M.A., and A. J. Wyatt, M.A. Cr. 8vo, pp. viii. — 2164-165. (London:
W. B. Clive.) Price 4/6.

This work contains in one volume The Tutoi-ial French Accidence and The
Tutorial French Syntax, the object of the authors being to give a clear and
fairly complete account of French inflexions and syntactical rules, and to bring
into prominence all points of fundamental importance. Special stress is laid
upon idiomatic usages, in which the English and French languages essentially
differ.

Common-Sense Euclid, Part I. By Rev. A. D. Capel, M.A.
Crown 8vo, pp. 155. (London : Abbott, Jones, and Co.)

This is devoted to the ist and 2nd Books of Euclid, and contains upwards
of 300 graduated Riders and Hints for their Solution. \xy this (the fourth)
edition the figures are inserted in the text.

A New English Dictionary on Historical Principles. By
Dr. James A. H. Murray, Jan., 1896. (Oxford: Clarendon Press.) 2/6.

The last part of the Oxford English Dictionary contains the words between
Development and Diffluency, thus finishing the words in De and proceeds
with those in Di, and includes a long series of technical and scientific terms of
ancient, medi;T;val, and modern formation, amongst which we notice diabetes,
diagnosis, dialectic, diameter, diaphanous, diaphragm, and many others.

Analysis of the Chess Ending, King and Queen against
King and Rook. By "Euclid." Edited and arranged by E. Freeborough.
8vo, pp. xii. — 132. (Hull: 9 Parliament Street. London: K. Paul, Trench,
and Co. 1895.) P"ce 5/-

The remarkable positions brought about in the play of Queen v. Rook are
generally treated as if they were deficient in interest, and offered little practical
difficulty. The author in this treatise has, however, demonstrated that the
defence has numerous resources. Every variation from the main play has been
illustrated by a diagram, and treated as a problem. The Chess Player will
find much here to interest him.

The Unrivalled Atlas of Modern Geography. (Edinburgh
and London : W. and A. K. Johnstone. ) Price 3/6.

This well-bound and most useful Atlas contains 40 Maps and an Index of
20,000 names of places. The size of the maps is about 14^ in. by 11 in. They
are distinctly printed and nicely coloured.

The Oxford Thumb Prayer Book. (London: H. Frowde.)

Contains the Book of Common Prayer and Hymns, Ancient and Modern, in
perfectly distinct and readable type. The number of pages is 862, and size
2 in. by i| in. by | in. We believe the price of these books varies from 3/-,
according to binding, etc.

REVIEWS, 215

The Mite Bible.

The Midget Testament. (Glasgow : D. Bryce & Sons.)

These are undoubtedly the smallest Bible and the smallest Testament in
the world. The Bible is a reduced facsimile of the Oxford nonpareil i6mo
edition, with 28 reduced facsimile line illustrations. It contains 916 pages,
size if in. by i^ in., and weighs 180 grains.

The Testament is a reduced facsimile of the Oxford pica i6mo New Tes-
tament. Size 4 in. by ^ in., and weighs only 26 grains. Both are furnished
with magnifying glasses for reading. The type when magnified is very clear
and distinct. The price of the Bible is 2/3, the Testament 1/3.

The Animal World : A Monthly Advocate of Humanity.
Vol. 26, fol. pp. 192. (London : S. W. Partridge and Co. 1895.)

This volume contains the twelve monthly parts issued by the Royal Society
for the Prevention of Cruelty to Animals, and is full of interesting matter
relating to various members of the animal kingdom. It contains also a large
number of illustrations.

The Band of Mercy, Vol. XVII. 4to, pp. 96. (London :
S. W. Partridge and Co.)

Another book issued by the same Society, suitable for younger children, is
also full of interesting reading matter relating to animals, birds, etc. The pic-
tures in both books are sure to please our young friends.

The Book of the Fair. Parts 13, 14, 15, 16. (Chicago and
San Francisco : The Bancroft Publishing Co.) Price §1 each.

"The Book of the Fair" is the only work in any wise attempting to
reproduce in print the great Chicago Exhibition entire. It presents in attrac-
tive form the whole realm of art, industry, science, and learning as exhibited
by the nations, so far as can be done within reasonable limits. The entire
work will consist of 1000 imperial folio pages (12-f 16 in.), and will be com-
pleted in 25 parts.

In the parts before us the section devoted to Mines, Mining, and Metal-
lurgy is concluded ; other subjects considered are Fisheries and Pisiculture ;
Transportation ; the Live Stock Department ; and Anthropology and Ethnology.

The entire work, whether we consider the paper, print, or illustrations, is
excellent, and when completed will make one of the handsomest volumes we
have seen.

Beeton's New Dictionary of Every-day Gardening, Cr. 8vo,
pp. 731. (London: Ward, Lock, and Bowden. 1896.)

This is an entirely new edition, completely re-written, thoroughly revised,
and considerably extended, and forms a popular cyclopaedia of the theory and
practice of Horticulture, Floriculture, and Pomology in all their various
branches, to which also is added a Monthly Calendar of Garden Work through-
out the year. It contains a large number of illustrations and many good
coloured plates, each with a key giving the names of the flowers represented.
It is unquestionably a valuable and most useful book.

Die Naturlichen Pflanzenfamilien. By A. Engler. Nos.
126, 127, 128. (London: Williams and Norgate. Leipzig: W. Engelmann.)

These parts contain the continuation of the Acanthacese, by G. Landau ;
Myoporaceae, by R. v. Wettstein ; Phrymacese, by J. Briquet ; Plantaginacese,
by O. Harms and C. Reiche ; Verbenacet^ and Labiata;, by J. Briquet ;
Sabiacece, by O. Warburg ; Melianthaceae, by M. Gurke ; Balsaminaceee, by
O. Warburg and K. Reiche ; Rhamnacese, by A. Weberhauer. There are 49
well engraved illustrations, giving 351 figures.

216 REVIEWS.

The Royal Natural History. Edited by Richard Lydeker,
B.A. , F.R.S., etc. (London : F. Warne and Co.) i/- monthly.

Has now reached its 29th monthly part. The last two parts are devoted
almost exclusively to Fishes, of which there are four good coloured plates and
a great number of engravings.

The New Photography. By Arthur B. Chatwood. Cr. 8vo,

pp. 128. (London: Downing and Co. 1896.) Price l/-

Here we have something quite new ; indeed, all the new developments in
photography are practically considered. There are chapters on the X Rays,
Colour Photography, Psychic Photography, Retinal Impressions, Spirit Photo-
graphy, and Anaglypa. The author appears to be well up in Electricity. This
is indeed a very up-to-date work, and will afford subject for much thought.

The ABC of Modern (Dry-Plate) Photography. Cr. 8vo,
pp. viii. — 193. (London : The Stereoscopic and Photographic Co.)

This well-known little book has reached its 24th edition, each of 5,000
copies, and gives a large amount of information, which, although specially
valuable to a beginner, will be useful to a more practised hand. It is well
illustrated.

Bright and Son's ABC Descriptive Priced Catalogue of the
World's Postage Stamps, Envelopes, Post-Cards, etc. Cr. 8vo, pp. xiv. — 695.
(Bournemouth : Bright and Son. London : Simpkin, Marshall, and Co.
1896.) Price 1/9.

Stamp collectors will find this a very convenient and useful catalogue.
The stamps of each country are arranged in chronological order, according to
the date of issue. There is a good money table and a reduced facsimile of all
the stamps. We regret that these, in many cases, are not so distinct as we
could have wished, being, as we suppose, photo-reproductions of the stamps
themselves instead of from engraved blocks.

We have received from Messrs. Cassell and Co. :

The Story of the Heavens.

Science for All.

Battles of the Nineteenth Century.

European Butterflies and Moths.

Chums.

[ 217 ]

Some 1Rote0 on tbe IDictoria IRcgia.

By Charles Hoole, assisted by W. Harrow
(Curator of Sheffield Botanical Gardens).

N reading a few short notes on that truly royal
genus of the Nymphieacece, or Water-lily family, the
Victoria Regia, before a Sheffield audience, I
thought it would not be inappropriate to quote a
notice from the Horticultural Magazine, as that
work was edited by Mr. Robert Marnock, curator
•^J7f^^^ of" our Botanical Gardens, and published by the late
\?^W^9 Mr. G. Ridge, whose shop in King Street I well
remember as a general meeting place of those
interested in books and book-making (no allusion to the trade).
The extract is from the March No. of 1838, and is as follows; I
must ask you to bear in mind that it was written nearly sixty years
ago :^" An undoubted addition to a tribe of plants, at once so
beautiful and so circumscribed as that of the Nymphs or Water-
lilies, would be an event of interest, even if it only related to a
distinctly marked species of some well-known genus. But when
the discovery is not only a new genus, but a plant of the most
extraordinary beauty, fragrant, and of dimensions previously
unheard of in the whole vegetable kingdom, except in the collosal
family of Palms, an interest must then attach to it which can
rarely be possessed by a novelty in natural history.

" Such a plant is the subject of the following notice : — A
Water-lily, exhibiting a new type of structure, of the most noble
aspect, of the richest colours, and so gigantic that its leaves
measure above eighteen feet and its flowers nearly four feet in
circumference, was met with in British Guiana, in lat. 4^ 30' N.
and long. 58° W. nearly, by Mr. Robert Schomburgh, a German
gentleman, travelling on account of the Royal Geographical
Society, assisted by her Majesty's Government, for the purpose of
examining the natural productions of that part of the British
dominions. In an account of the plant transmitted to the Geo-
graphical Society, Mr. Schomburgh speaks thus of the discovery :

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. p

218 SOME NOTES ON THE VICTORIA REGIA.

" It was on the ist of January this year (1837), while contend-
ing with the difficulties Nature imposed in different forms to our
progress up the river Berbice (in Brit. Guiana), that we arrived at
a point where the river expanded and formed a currentless basin.
Some object on the southern extremity of this basin attracted my
attention. It was impossible to form any idea what it could be,
and animating the crew to increase the rate of their paddling we
were shortly afterwards opposite the object which had raised my
curiosity — a vegetable wonder : All calamities were forgotten ;
I felt as a botanist, and felt myself rewarded. A gigantic leaf,
from five to six feet in diameter, salver-shaped, with a broad brim,
a bright green above, and a vivid crimson below, rested upon the
water. Quite in character with the wonderful bay was the luxu-
riant flower, consisting of many hundred petals, passing, in alter-
nate tints, from pure white to rose and pink. The smooth water
was covered with the blossoms, and as I rowed from one to the
other I always observed something to admire."

Some drawings were sent home by Mr. Schomburgh. He con-
sidered the plant a species of NymphcEa^ and was desirous that it
should be distinguished by the name of The Queen — a wish with
which her Majesty has been graciously pleased to comply.

He adds that the flower is much injured by a beetle {Trichius
sp. ?), which destroys completely the inner part of the disc. We
have counted sometimes twenty to thirty in one flower. Specimens
are deposited in the cabinets of the British Museum.

So much for the account in a local publication ; but it is now
stated that the first traveller who discovered this plant was Hsenke
in 1 801 ; but M. D'Orbigny was the first to send specimens to
Paris in 1828. They were, however, neglected or overlooked. In
a work published some few years after this time, M. D'Orbigny
mentions having discovered the plant in the river Parana in British
Guiana. It was known, he says, to the natives by the name of
Irupe, in allusion to the shape of the leaves, which resembles that
of the broad dishes used in the country. The Spaniards called
the plant Water-maize, as they collect the seeds and eat them when
roasted. In 1832 a German traveller found it in some tributaries
of the Amazon ; but it was not until the late Sir Robert Schom-
burgh discovered it in the river Berbice in 1837, as you have

SOME NOTES ON THE VICTORIA llEfJIA. 219

before heard, that public attention was drawn to the magnificent
plant. The Victoria Regia is a very rapid grower, and in conse-
quence of that characteristic an observer was able to note the rate
of growth every five minutes, and his results show very clearly the
frequency and extent of the spontaneous irregularities in the rate
of growth. The observations were taken in the month of August.*
From eleven in the evening until twelve midnight the lengths of
growth were, roughly speaking, from rather more than a quarter of
an inch to about three-eighths of an inch every five minutes, giving
a total of about four inches for the hour. From twelve midnight
to one a.m. the lengths were from rather more than a quarter of
an inch to nearly three-quarters of an inch, giving a total of about
five inches for that hour. The temperature both of water and air
scarcely varied, and the plant was exposed to candle-light. The
foregoing measurements refer to the petiole, or leaf stalk, only. I
must now express my indebtedness to my friend, Mr. Harrow, the
distinguished curator of our Botanic Gardens, for much valuable
assistance and for the material for the slides which I have the
pleasure of submitting to your inspection.

In the summer of 1893 — which, you may remember, was a
very bright and sunny one — Mr. Harrow was very successful in
the cultivation of Victoria Regia, having no less than thirty-eight
flowers, most of them twelve and a-half inches in diameter. A
few of the later ones were rather smaller, although perfect in form
and colour. The first opened on July 9th and the thirty-eighth
on Nov. 26th. Thirty-eight is an exceptionally large number of
flowers for the plant to bear during one season, and it is doubtful
if so many will be seen again for some years. The seed of the
original parent was selected a few years ago from the finest plant
that could be found amongst some thousand acres of Victoria
Regias. 1 may say that seeds two or three seasons old germinate
sooner than new ones. The Victoria Regia has been in cultiva-
tion in our gardens some forty years, and only during one year has
the house been without its royal occupant. There are but two
other botanical gardens in England where the Victoria Regia can

" Lectures on the Physiology of Plants. By Dr. Sydney Howard Vines,
F.R..S., late Fellow of Christ's College, Cambridge. Published by the Cam-
bridge University Press. •

220 SOME NOTES ON THE VICTORIA REGIA.

be seen ; these are the Gardens at Kew and the Botanical Gardens
in Regent's Park, London. It is also grown in two or three
private establishments in this country. In the past season of 1895,
some exceptionally large leaves were produced, which I think may
fairly claim to be called record leaves. The largest was seven feet
three inches in diameter ; a number of others ranged about seven
feet, with upturned rims, varying from three to four and a-half
inches. The fully-grown leaves can sustain considerable weight
without being submerged. A chair was placed upon one of them,
having previously had two thin boards put to prevent the chair-legs
from bursting the leaf. Mr. Harrow and some of the gardeners
sat upon the leaf in turns, and in one of the trials a weight of
about eleven and a-half stones was sustained. This plant pro-
duced twenty-seven flowers. The first opened in the last week of
July and the last the first week of November. The flower lasts
about three days, opening in the evening and giving off a delight-
ful perfume, which has been perceived forty or fifty yards from the
house when the ventilators in the roof were open. The colour of
the flower when first opened is pure white, but on opening the
following evening is a deep rose and loses its fragrance. After the
third day the ovary becomes gradually submerged and the seeds
ripen, which takes from two to three months to accomplish, a large
number being produced in an ovary.

It is on record that when Sir J. Paxton got his first bloom at
Chatsworth, he was so delighted with the flowers that he chartered
an express train to Eastbourne, where the Duke was staying at his
marine residence, and arrived there just before the Duke's break-
fast-time, and he put it on the table so as to be the first thing
which would greet him in the morning. " Well done, Paxton ! "
was the laconic commendation of the Duke, and the great gar-
dener went back to Chatsworth highly pleased.

The plant, as you are now aware, is, under cultivation, treated
as an annual, a fresh one being raised every year. The seed is
black and about the size of a pea. It is sown in the early part of
January, when it is put into a tank heated with hot-water pipes,
when a temperature of about 85° to 90^ F. is maintained in order
to germinate the seed. The young plant is potted on until April.
It will then have three or four fiat leaves about twelve inches in

SOME NOTES ON THE VICTORIA REGIA. 221

diameter, and is placed in about six tons of prepared soil in the
basin of the tank, which is about eight feet by two feet six
inches deep. The tank itself is about twenty-eight feet in
diameter, containing water kept at a temperature as near 85"^
as possible. The plant soon becomes- established, covering
the surface of the water with its handsome leaves. As a
rule, only one flower expands at a time. The first leaf pro-
duced is very remarkable, including the stalk, which is scarcely
distinguishable from it, is about two inches long and devoid
of spines ; the second rather longer, and in it the leaf and
stalk are differentiated, and two or three spines appear on the
stalk ; the third is somewhat larger and rather similar in
shape, with more spines on the stalk ; the fourth assumes
an oval form with pointed ends, the one over the stalk with
a deep notch in it ; spines begin to develop on the chief
nerve. The colour underneath is of a reddish hue, and the upper
surface is marked with chocolate-coloured blotches. The stalk
lengthens and is covered with small spines. These spines have
■spiral vessels and a small cavity in their interior, opening by a
little pore at the top. From the under surface of the base of the
leaf-stalks numerous adventitious roots are given out. The leaf-
stalks, flower-stalks, and nerves are traversed by numerous air-
channels, which make the enormous leaves so well adapted to float
on the water, when we remember the size and number of the veins.
In the leaves of submerged water-plants, however, the strands are
insignificant and many are even destitute of vessels, which is easily
understood, as the need of resisting pressure and bending in sub-
merged leaves is very slight. In most flat membranous leaves,
which have one side directed towards the sky and one towards the
earth, stomata are entirely wanting on the upper surface, being
restricted to the under side. An exception to this is afforded by
the leaves of the Victoria Regia and some others, they being
covered with stomata on the upper side, while on the lower side,
which is in contact with the water, stomata are entirely absent.
It may be observed that the water-lilies have small stomata, and
land ones, which belong to another order ( Liliacecz),. have large
ones. The whole of the upper surface can receive the rays of the
sun, and is thus warmed and illuminated throughout. The under-

222 SOME NOTES ON THE VICTORIA REGIA.

side of the leaf is coloured violet by a pigment called anihocyatiin,
which is believed to change light into heat, and thereby materially
help to warm the leaf The leaf is pierced with numerous pores,
which allow the rain or other water which may accumulate upon
them to pass through, and thus prevent the leaf from being sub-
merged. The leaves are only armed with prickles on the under
surface and on the turned-up margin — i.e., only where they are
exposed to the attacks of plant-eating aquatic animals.

It is an interesting fact that many woody plants are only pro-
tected while young — i.e., while they are short, and their foliage can
be reached by ruminants, such as goats, sheep, and oxen • but on
the branches beyond the reach of the mouths of these animals^no
prickles and spines are developed.

I cannot close this paper without a word on a remarkable
companion which the Victoria Regia had in the year 1893, and I
will add a note which Mr. Harrow has kindly written on that
curious organism, the Fresh-water Medusa, Li7itnocodium Sowerbii.
It is as follows : —

Ifresb^water /llbeDusa, XimnocoMu?n Sowerbii.

By William Harrow.

The Fresh-water Medusa which appeared in the Victoria Regia
tank during the summer of 1893 has proved a most interesting
topic to zoologists and many others, and information relating to it
has been widely circulated throughout the country by various
articles in the newspapers.

Professor E. Ray Lankester, in a most interesting article in
Nature, says : — " For three years nothing has been seen of the
Fresh-water Medusa in the Regent's Park, and naturalists had
given up hope of carrying on any further investigation into its
life-history. It seemed as though this beautiful little organism —
brought, we know not how or whence, into the midst of London —
had, like some mysterious comet, unexpectedly burst on the zoo-
logical world and as unexpectedly disappeared.

" I was, therefore, greatly astonished to hear in September from
my friend, the Director of Kew, that the curator of the Sheffield
Botanic Gardens had discovered it in a quantity in the Victoria
Regia tank under his care during the present summer, and I was

SOME NOTES ON THE VICTORIA REGIA. 223

soon after delighted by the safe arrival from Sheffield of a bottle
containing living, well-grown specimens of the familiar jelly-fish."

The Fresh-water Medusa was first discovered in the Victoria
Regia tank of the Botanic Gardens, Regent's Park, London, in
1880, and had never been found elsewhere until last year, when it
was observed in numbers swimming about the Victoria Regia tank
in these Gardens. The question at once arose, How came it to
Sheffield ? Professor Lankester, in the article alluded to, says : —

" The question as to how the jelly-fish got to Sheffield is easily
answered. Water plants {Nyinphceaccce and Pontederid) were sent
from Regent's Park to Sheffield, to re-stock the tank there, on
April 4th, 1892, and on April 7th, 1893. Hence there was the
possibility of some of whatever germs of Limnocodium existed in
Regent's Park being transferred to Sheffield. The curious thing is
that in 1892 and 1891 no Liinnocodium was seen in the original
source — viz., the Regent's Park tank, nor in 1893, excepting a few
sent from Sheffield and placed in that tank by Mr. Sowerby.

This is the first instance recorded in which another Victoria
Regia has been " infected " with Limfiocodiimi from the original
Regent's Park tank, excepting when the new tank in Regent's Park
was in 1890 infected from the old one, by the transference to it of
weeds and roots containing the germ of the jelly-fish.

To those unacquainted with this little creature the following
description may be interesting : — " The general form of the animal
resembles a small, shallow, nearly hemispherical bell, of the most
delicate structure, transparent almost as glass, the tentacles of a
beautiful opalescent white, and as seen floating in the water
resembles the ordinary jelly-fish, but from which, however, it
differs in many particulars ; one of the peculiar features being that
the tentacles are extended upwards, when the animal is floating,
instead of hanging from the bell, as in most other members of the
group. The size varies much according to age. Individuals have
been noticed as small as pins' heads, one-thirtieth of an inch, and
from this size ranges up to one-third of an inch, or of full-grown
adult specimens, fully expanded, to half-an-inch in diameter.

The bell or umbrella is quite transparent. The marginal ring
bears three sets of tentacles. The first, a set of four large, primary
tentacles ; the second, a tier of twenty-eight or more, secondary

224 SOME NOTES ON THE VICTORIA REGIA.

medium size ; and the third, a tier of one hundred and ninety or
more, small, tertiary tentacles, placed in groups of six between the
secondary ones. The stomach is long and tubular, extending
below the disc, and may be likened to the stick of an umbrella.
The mode of progression through the water is by the sudden con-
traction of the marginal ring, exactly like the rapid closing and
opening of an umbrella or parasol, and the individual appears
capable of directing its movements in whatever direction it
pleases."

These jelly-fish have been sent to various places, with the view
of establishing it in other quarters, though we are afraid the deed
will be futile, as they have never been known to reproduce
themselves. Professor Lankester, in a letter to the writer,
states that the jelly-fish are produced by a little polyp, which
multiplies and creeps on the rootlets of NyniphceacecE and Po?ite-
deria. At certain times the polyp nip off a round piece from their
free extremity, which becomes a jelly-fish and grows and enlarges
to the adult size whilst floating in the water.

The Rontgen Rays and Precious Stones. — The observa-
tions made by Bugust and Gascard on the possibility of distin-
guishing diamonds and jets from many of their imitations by the
application of the .v rays have caused them to make further
experiments. The transparency of aluminium to the rays has
since led them to study the effects produced in the case of precious
stones, of which that metal is a constituent. They find that the
crystalline forms of alumina known as corundum, ruby, sapphire,
emerald, topaz, and cat's-eye, may be classed between their imita-
tions and the diamond with regard to the effect produced. The
torquoise, which consists of aluminium phosphate, is also clearly
distinguished from its substitutes by means of the rays, and mallite
is almost as transparent as carbon. Fine pearls of small size are
less opaque to the rays than false ones of the same size, and may
be clearly distinguished from them ; but in the case of larger
specimens the result is less certain, depending greatly upon the
manner in which the false pearls have been made. — Pharm.Journ.

[ 225 ]

®b5crvation6 on tbc Structure of
C^etopus CauM^ue/'

IN the following paper a short account is given of the structure
of the vegetative and reproductive organs of Cystopus candi-
dus, a fungus parasitic on cruciferous plants, and especially
abundant on the common Shepherd's-purse {Capselia bursa-pas-
ioris), on which it forms shining white patches, often of consider-
able extent, on the stems, leaves, and fruits.

The mycelium consists of non-septate hyphae, which ramify
in all directions between the cells of the host plant, and often
produce extensive hypertrophy of the organ attacked. Here and
there small spherical haustoria are developed oil the hyphae, and
these penetrate directly into the cell cavities. Both hyphae and
haustoria contain a granular protoplasm, in which numerous nuclei
can be seen. The structure of these nuclei can be made out by
careful staining and examination under a sufficiently high power,
as was shown by Fisch. Each nucleus is vesicular, and contains
a large nucleolus, which stains deeply, and is surrounded by a less
deeply stained substance, in which some indications of a granular
or thread-like structure may at times be observed.

The reproductive organs are of two kinds, asexual and sexual.
The asexual organs are formed just beneath the epidermis of the
host-plant ; they are club-shaped branches of the mycelium, from
which zoosporangia are cut off by constriction and formation of a
double wall at the apex. These branches contain granular proto-
plasm derived from the mycelium, and numerous vacuoles. A
few nuclei are found scattered in the protoplasm, the number
being variable, from five to twelve. The structure of the nucleus is
similar to that in the mycelium, but is more easily made evident.

In the formation of the sporangium a part of the protoplasm
accumulates at the apex, together with a few nuclei, four or five,
or perhaps more ; this is then separated from the club-shaped
branch by constriction of the cell-membrane. A double cell-wall
is then formed which completely cuts off the sporangium from the

* Extracted from a paper by Harold T. Wager in the Report of the
British Association, by G. H. Bryan.

226 THE STRUCTURE OF CYSTOPUS CANDIDUS.

branch on which it is formed. The sporangium is thus, from the
beginning, a muUi-nucleated cell. Each nucleus at a later stage
becomes the nucleus of a zoospore without undergoing further
division. The nuclei found in the club-shaped branches are
probably derived directly from the mycelium, no division-stages
having been observed in the sporangiophore itself It is possible,
however, that owing to the smallness of the nuclei the division-
stages are masked.

The sexual organs, antheridia and oogonia, also contain
numerous nuclei. According to Fisch, the oogonium contains
from ten to twenty nuclei, the antheridium three or four. More
than this have been found in many cases. In the formation of
the oosphere, the protoplasm separates into periplasm and gono-
plasm, a cell-wall appears round the gonoplasm. A large number
of nuclei remain in the periplasm, but the gonoplasm does not
appear to possess nuclei at this stage ; at a later stage, however,
during the formation of the exospore, a number of nuclei make
their appearance in the oospore around a central oil-globule.
These observations do not agree with those of Fisch. According
to that observer, all the nuclei of the oogonium fuse together to
form the nucleus of the oosphere. According to Dangeard, the
central nucleus of Fisch is nothing more than an oil-globule, and,
so far as my observations go, I agree with him. Soon after the
separation of the oosphere a quantity of oil begins to accumulate
in or near the centre. This is stained deeply by hsematoxylin or
picro-nigrosin, and might easily be taken for a nucleus. Its oily
nature may be determined, according to Dangeard, by soaking
the sections for some time in chloroform, when it disappears, and
a vacuole is left. The oil-globule gradually increases in size,
until the exosporium is fully formed. It then takes up about
one-third of the diameter of the cavity of the oospore.

The disappearance of the nuclei of the oosphere during the
earlier stages of its development, is probably only apparent, some
change taking place, of the nature of which we are not yet cogni-
sant. It is probable that these nuclei are included in the oosphere
at the time of its separation from the gonoplasm.

The problem of fertilisation is an important one, but is difficult
to settle. At an early stage the antheridium contains numerous

THE PYGIDLUM OF THE COMMON FLEA. 227

nuclei, which pass over, at a later stage, into the fertilising tube of
the antheridium, but whether they pass into the oospore is a ques-
tion which has not yet been settled.

[An interesting, illustrated account of " Cystopus, or White
Rust," was given in the Journal of Microscopy and Natural Science
for June, 1885.— G. H. Bryan.]

^bc ip^tjiMum ot the Common jflea**

By Dr. Alfred C. Stokes.

THIS organ has been studied so frequently, and by so many
microscopists ; it has been used for so many years as a
test of certain qualities in objectives, that further notes on
the subject might be deemed superfluous; it might well be thought
that the last word must have been spoken about a matter so com-
mon, not to say so hackneyed. It is because the pygidium has
been so frequently examined that I cannot divest myself of the
belief that the structural features which I have recently observed
must have been repeatedly seen by microscopists, although these
morphological points seem to be actually undescribed. I can find
no reference to them in the literature of the subject which I have
been able to examine, yet they are so prominent and so conspic-
uous that it is difficult to imagine how they could have been so
long overlooked, if they have been, especially after such accom-
plished microscopical observers as Van Heurck, Dallinger, Nelson,
Carpenter, have used the pygidium as a test. But some of these
investigators, notably Dallinger and Nelson, have lately described
previously unobserved features, or features which have previously
been misinterpreted.

Mr. E. M. Nelson was the first to describe correctly the form
of the so-called spines or hairs which clothe the inter-areolar sur-
face, calling them lambent, meaning that they are flame-shaped,
thus using the word out of its proper signification, for "lambent"
means, not flame-shaped, as the eminent British microscopist

* From The Journal of the New York Micro. Soc.

228 THE PYGIDIUM OF THE COMMON FLEA.

intends to suggest, but something quite different. Other observers
had noted these spines, and indeed had figured them as stout,
tapering bodies arising from a circumvallate depression, to the
base of which each was said to be attached by a socket-joint.
The fact is that no such socket-joint, nor any structure resem-
bling it, is present on the inter-areolar surface of the pygidium .
" As an example of erroneous interpretations," says Dallinger
in his edition of " Carpenter, " " the representation of the
pygidium of a flea by some leading sources of information of
a few years ago may be instanced. It was a special test of
many authors, and has been carefully figured ; this shows that
it was not an accidental error, which it might have been if it
were merely an ordinary object ; it is an error depending in
all probability on a faulty system of illumination. Moreover,
the error cannot be attributed to the object-glasses of the time, as
it is a low-power object, and the low powers of that day were quite
as good as those lately in use. In the descriptions and in the
drawings, often beautifully executed, the hairs proceeding from
the centre of the wheel-like discs are represented as being ' stiff
and longish bristles,' thick at one end and tapering off to a point.
And the small hairs round (sic) are described as 'minute spines' ;
in the drawing they are like the spinous hairs of an insect, and
have the usual socket-joint at the base. In reality, the 'stiff and
longish bristle ' is an extremely long and delicate filament, totally
unlike a bristle, being not tapered but of nearly uniform thickness.
The ' minute spines ' are in reality very curious hairs, and, as
far as we at present know, unlike any others. They are delicate,
lambent, bulbous hairs."

These "stiff and longish bristles," which issue from the areolae,
appear to be fragile, and are, as a consequence, readily broken,
when they are observable on the preparation as stout, truncated
filaments, usually with no trace of decreasing diameter. But when
they are unbroken they certainly do taper; and do so conspic-
uously, at least with the specimens which I have seen. If a true
bristle must taper, then are these true bristles.

The flame-shaped hairs are narrowed with a regular gradation
from the somewhat bulbous base to the usually curved and acumi-
nate tip. But if the classical socket-joint of these inter-areolar

THE PYGIDIUM OF THE COMMON FLEA. 229

hairs can be proved to be an error of observation, as can be
easily done, then it is not unlikely that there are other structural
points about the organ which may have been overlooked or mis-
interpreted. In fact, there seem to be several.

Of some of those to be mentioned here there is absolutely no
doubt ; of a single one there must be doubtful acceptance until
the microtome can be brought to bear on the pygidium, when the
problem may be readily solved. I have not even the skill of a
novice in the use of the microtome, and those of my friends and
correspondents who have attempted to section the pygidium have
failed, either on account of the horny character of the subject, or
because of the lack of sufficient material. When sectioned it
will not be what Dr. Dallinger calls a low-power object ; even in
its totality it is far from being that.

The areolae, or those superficially wheel-like bodies which,
in number from thirty-two to thirty-eight (Van Heurck), constitute
the double, somewhat reniform organ called the pygidium, are not
the simple bodies which they are usually supposed to be. The
ordinary statement of the books is, as Dr. Van Heurck puts it in
the fourth edition of his work on The Microscope, that, "The pygi-
dium of the flea is composed of two lobes and exhibits from
thirty-two to thirty-eight long, stiff hairs implanted in the centre of
each of the areolae, each one being surrounded by a row of little
cuneiform elevations. The inter-areolar spaces are covered with
small spines. A good objective should show these areolse clearly
defined in all their parts, and the elevations should appear cunei-
form, and not round as they are figured by Dujardin." This is
not all of the structure as I see it with the best objectives of
Reichert, Zeiss, and of Spencer.

Each areola is in reality a follicular depression, varying in
dimensions to a degree perceptible even without the use of the
micrometer, but averaging, perhaps, about 1/3000 inch in depth ;
and each contains, not only the long central, bristle-like filament
and the cuneiform projections, which are said to form a single
row, but a somewhat complex,' strongly chitinous system of rods
and wedges and membranes, the whole apparatus being covered
by an elevated, membranous dome about as high above the gene-
ral surface as the follicle-is deep below it, and with a central eye

230

THE PYGIDIUM OF THE COMMON FLEA.

through which the long bristle projects, tlie dome itself bearing
some minute external appendages. The areolse are by no means
the simple, uncomplicated objects they are commonly described
and figured to be. They have been looked upon by microscopists
as low-power objects, as Dr. Dallinger describes them, but they
will prove themselves worthy of study with the highest-power ob-
jectives at our disposal. The structure of these wonderful bodies,
as I see it, is shown in the accompanying diagram, Fig. 17 : —

Fig. 17.
Diagram of an areola from the Pygidium of a Flea.

The walls of each follicle are vertically fluted at regular inter-
vals, and the upper margin is, as a result, broadly crenated. The
cuneiform projections (they are not elevations as commonly des-
cribed) converge towards the centre from a comparatively wide
band of encircling chitin, and each is outwardly continued toward
the bottom of the follicle by a curved, rod-like body, which at the
base becomes continuous with a second set of wedge-shaped pro-
jections, often less strongly chitinous than the upper row, and
always rather shorter. There is not a single row of these cunei-
form projections which have so long been used as a test for
definition, and which Dr. Van Heurck says Dujardin figures as
being round. There are two rows entirely distinct from each
other, but connected exteriorly by the vertical rods referred to.

THE PYO[DIUM OF THE COMMON FLEA. 231

and shown in the diagram. At the outer surface of these vertical
rods, that is, between them and the internal wall of the follicle, is
a delicate membrane which constitutes the outer boundary of the
complicated apparatus, and is continuous with the membrane
which forms both the upper and the lower surfaces, and fills the
spaces between the wedge-shaped projections. This produces a
circular chamber strengthened outwardly by the vertical rods, and
above and below by the cuneiform projections. If there were
nothing more to the intra-foUicular apparatus this chamber would
be a simple, circular passage open at the centre, through which
the long bristle passes. But the circular region is not open toward
the centre ; it is there closed by a slightly inclined membrane,
which extends from the tips of the upper wedges obliquely outward
to the tips of the shorter lower projections. This membrane closes
the circular chamber, and produces a more or less conical space
at the centre of the follicle, through which the long filament issues.
But whether or not it completes the structure of this part is doubt-
ful. I think it does not. But to become positively assured as to
that, a study of sections is necessary, and here the expert micro-
tomist will find a subject worthy of his steel. And here, too, he
will meet with an object that will tax his skill in the illumination
of the microscope, and his ability to manipulate the best high-
power objectives. For this is not a low-power object.

But while I am unable to prove to others that my opinion is
correct, still that opinion is that this circular chamber is divided,
by vertical membranes, into as many cells or compartments as
there are wedge-shaped projections in each row, a membrane ex-
tending from a cuneiform body above to the one directly below.
I am making no positive statement about this minute structure,
and it is minute enough to be a delightful task for the lover of the
delectable instrument ; I am expressing only an unproved opinion,
leaving to the microtomist the pleasure of deciding the question,
and, I am free to confess, envying him the skill needed in the
delightful work. However, if these vertical membranes exist, and
judging from certain optical appearances I think they do exist,
then is the pygidium of the despised parasite one of the most
remarkable studies with which the microscopist can become
acquainted.

232 THE PYGIDIUM OF THE COMMON FLEA.

But perhaps the most pleasing structure, which is also one of
those surprising things in Nature, is the delicate dome which arches
above each follicle with its enclosed apparatus, and through whose
central eye the long tapering filament projects. If this domoid
membrane has not previously been observed, I am at a loss to
account for the oversight. It is almost conspicuous ; it demands
only a slightly upward focus to define its rotundity and its circular
eye ; if the long bristle is followed from tip to base, the dome can
scarcely fail to make itself seen.

This over-arching membrane is set down above the follicle,
and is a little greater than it in diameter, the greatest width of the
dome being about i/i,8oo inch, with about 1/2,000 inch to that
of the depression which it covers. In the diagram it is shown as
it appears in surface view, with a regularly spherical outline, the
summit somewhat flattened and the region about the central eye
conspicuously depressed. In some specimens, probably in all,
when seen in profile, the dome is widened above, and the convex
walls slope inward to the base. But as to the existence of the
domoid membrane there is not the slightest doubt. It is present
above every pygidial areola, adding much to the interest of the
orgaHj somewhat to its complexity, and happily adding emphasis
to the general belief that the pygidium is an auditory organ. The
function of this membranous dome can be readily inferred.

It possesses, however, some minute appendages whose function
is not so easily conjectured. Around the eye of the dome, as
shown in the diagram, is a single row of from eight to ten projec-
tions which, for want of a better name, may be called setae. These
are positively not the tips of the flame-shaped hairs, and they are
as positively not minute folds in the membrane of the dome, but
strictly independent organs, minute enough to satisfy the most
exacting microscopist who likes to work with high powers. In
estimated length they vary from 1/15,000 to 1/20,000 inch. I have
no micrometer ruled fine enough to measure such setae, but the
estimate seems to be at least within the actuality.

These small objects arise from the surface of the dome in a
regular row, and take varying positions, being sometimes perpen-
dicular at the edge of the eye, at times leaning over the margin ;
in other instances they appear further down the slope, standing

THE PYGIDIUM OF THE COMMOX FLEA. 233

upright or variously inclined or curved. They convey the idea of
solidity and of firmness, having nothing of the aspect of a bristle,
for they seem not to taper, but to be minute cylinders, each appa-
rently arising abruptly from its base, and having a truncated summit.
These appearances, however, may be illusory, as the sets are so
exceedingly minute that it is difficult to decide positively. But as
a test for definition, the reader will find the little appendages
entirely satisfactory. He may perhaps think that the resolving
power of the objective should likewise not be slight, and I should
be disposed to agree with him.

All this structure, which the reader must admit to be sufficiently
complex, is visible within and above the pygidial areolae of all the
common species of Pulex which I have examined, but it seems to
be rather larger and more conspicuous within those of Pulex irri-
tans, especially with those specimens which are to be had in Cali-
fornia, where, in addition to big trees and some other large things,
our microscopical friends are so fortunate as to have big fleas.

The Spider Plant. — Travellers who visited or passed the
Cape Negro country of Africa, says the Morning, often heard from
the natives of a plant that was part spider and threw its legs about
in continual struggles to escape. It was the good fortune of Dr.
Welwitsch to discover the origin of the legend. Strolling along
through a wind-swept table-land country, he came across a plant
that rested low on the ground, but had two enormous leaves that
blew and twisted about in the wind like serpents ; in fact, it looked,
as the natives had said, like a gigantic spider. Its stem was four
feet across and but one foot high. It had but two leaves in reality.
They were six feet to eight feet long, and split up by the wind so
that they resembled ribbons. This is probably the most extra-
ordinary tree known. It grows for nearly, if not quite a century,
but never upwards beyond about a foot, simply slowly expanding
until it reaches the diameter given, looking in its adult state like a
singular stool on the plain from ten feet to eighteen feet in circum-
ference. When the wind came rushing in from the sea, lifting the
curious ribbon-like leaves and tossing them about, it almost
seemed to the discoverer that the strange plant had suddenly
become imbued with hfe and was struggling to escdi^gQ.— Journal
of Horticulture.

International Journal of Microscopy and Natural Science.

Third Series. Vol. VI. Q

[ 234 ]

Zimc, Space, anb 3nvi6tble Morlb?.

By W. D. Barbour.

Part I.-TIME AND SPACE.

THE twin mysteries of time and space may well be regarded
as modern discoveries. Primeval man interpreted them by
the immediate things of sense. The stars were brilliant
gems, and the planets wandering stars. Sun and Moon were gods,
because of material benefits conferred. Space was hmited by
sight, and time by lunations, seasons, and history. The Infinites
were there just as now, but imagination was feeble, and conceptive
power wanting. Yet knowledge increased, the mind grew, the
horizon dilated, and by slow degrees greater distances in space,
and longer ages in time, were brought within the compass of
thought. In the light of limitations such as these, our interpreta-
tions of old or primitive writings necessarily require considerable
modification. Unfortunately, the same phraseology which expressed
the ancient limited conception of the infinite in time and space,
expresses also ours. The words are the same, but the applied
meanings are incomparably different. Slowly, even reluctantly,
have translators, students, and commentators, allowed for the
absence of that knowledge and mental development which the
present age so amply enjoys. Thus the phrases " everlasting,"
" without end," " for ever and ever," " eternal," " evermore,"
"immortal," " beginning and end," "all the earth," "the whole
earth," " under the whole heaven," " the heavens," etc., embody
meanings indefinitely larger to us, as compared with those under-
stood by our forefathers, five hundred, to say nothing of five thou-
sand years ago. Reason suggests that such phrases, however
susceptible, more or less, of infinite meanings, were not spoken,
or written, " over the heads " of the people to whom they were
addressed, but were rather directed to the level of their limited
comprehensions. Such considerations should not be overlooked
in our study of the Biblical stories, aUke of " Creation," and of
other natural phenomena.

Just as the revelations of Geology burst the shackles of the
human imagination, which, until the present century, shut up alf

TIME, SPACE, AND INVISIBLE WORLDS. 285

terrestrial time within the insignificant limit of six thousand years,
so have discoveries in Astronomy overleaped those boundaries of
space arbitrarily imposed by appearances and ignorance, which in
present as well as in former ages have sought to make Earth the
centre of the Universe, and to cabin and confine all Creation
within the microscopic limits of a few thousand miles. With the
advent of the telescope in 1609, when planetary discs, revolving
satellites, and sphericity of Sun and Moon were first demonstrated
to human sense by Galileo, there gradually dawned upon thinking
minds the conviction that other globes and other worlds might
exist, in which life in its thousand forms, such as we here see
around us, might exist and flourish ; and in which beings like our-
selves, enjoying the liberty which accompanies responsibility, are
working out their own destinies. The wide welcome everywhere
and at all times accorded to this suggestion of life in other Planets,
and in which we recognise the ever-enlarging social instinct of human-
ity, strongly suggests its naturalness, and therefore to some extent
its likelihood. We are thus led to indulge the thought, and to
anticipate the possibility, however seemingly remote or improbable,
of communicating with kindred minds and hearts, upon one or
other of those Planets which adorn our midnight skies. Proctor
believed that it is in this aspect that astronomy acquires what
powerful hold it possesses upon the popular mind.

During the five thousand years in which Astronomers were
pondering and questioning in vain the distance and constitution
of the Stars, and when at length their powers of belief were
strained, as the piling up went on of the big distance figures, the
Astronomical mind was unconsciously all this time being inducted
into one of the mysteries of the Infinite. Compelled by the logic
of exact measurements, the Astronomer rose to the occasion, and
strove to grasp the pregnant truth that our Sun, vast in bulk
(860,000 miles diamater) as he is, is yet, with all its planetary and
other attendants, utterly lost, and sinks into insignificance, amid
that mighty host of Suns and Systems which micrometer and
spectroscope reveal as in swift and ceaseless motion through the
vast abysses of space. Human sight, thus multiplied by the
telescope a thousandfold, transporting us instantaneously into
recesses of space, so remote that light from thence requires four

236 TIME, SPACE, AND INVISIBLE WORLDS.

thousand years to reach us, must needs intensify our conceptions
of the Universe, and prepare our minds for the bewildering truth
that within that radius, on every side of this our infinitesimal globe,
Planets large and small, millions in number, are now evolving like
our Jupiter, Saturn, Uranus, and Neptune, or are already evolved
like our Mercury, Venus, Mars, or Earth. As man cannot prescribe
limits to Creation, neither should there be pause or limit to his
mental efiforts to grasp ever more and more of the illimitable.
Whilst Professor Cleland contends that evolution of the human
body has already reached its climax (as shown in the front curving
in of cranium and brain, forming an arch of about one hundred
and eighty degrees, of irregular cylindrical shape, commencing at
point of communication of skull with spinal canal round to point
above the nose, the extremes being thus nearly parallel), and that
" the pinnacle of matter " is now reached, and the great object of
its creation now attained, in the evolution of mind ; so in the
present outgoings of thought and aspiration towards the Infinite,
we see one of the signs that mind, in its loftier branches, has
already outgrown the physical capacities of its tenement, and is
now preparing to commence a new and higher course of evolution.
In the question of evolution of Suns and worlds, it is natural
that much emphasis should be laid upon analogy. Analogies and
probabilites may be regarded as instances, examples, or side-lights
of that which is described as the great law of Continuity, and
which we may look upon as the final expression of the oneness
and harmony of all Nature. Drummond has defined the law of
Continuity by picturing a world without it, that is, one in which law
and order are not continuous, and therefore, in which dis-continuity
exists. In such a world, cause and effect would cease ; no
dependence could be placed upon anybody or anything, everything
happening by accident or chance. Sun might rise one day in the
north and set in the east ; another day at midnight, or not at all.
Moon might appear full when it ought to be crescent, or rising
when it ought to be setting. Jupiter might appear horned, and
Venus with rings and satellites. The Stars, no longer " fixed,"
might wander hither and thither, carrying confusion inextricable
into all the Cardinal points and signs. Some years might be all
summer and others all winter. The laws of light and gravitation

TIME, SPACE, AND INVISIBLE WORLDS. 237

might change at any hour. Thus, the natural order of everything
might at any moment be reversed, Earth become mad, and its
inhabitants lunatics. Only thus, by extreme contrast, can we
properly estimate the immense value and importance to us, of this
law of Continuity throughout the Universe. Man finds in this
Continuity his promise and warrant, that, " if he depend upon
nature, his intellect shall not be insulted, nor his confidence
abused ; " and " if man has to trust nature, that his reason shall
not be put to confusion." Continuity, it has been well said, " is
the expression of the Divine veracity in nature."

Assuming, then, a universal oneness in nature, we should
expect to find, as -discovery progresses, a general harmony between
truth known and truth not known ; and that the great lines of
natural laws, which prevail throughout, and (if we may speak of law
as a governing agent) regulate our Solar System, are not only
similar to, but identical with, those which exist throughout the
Stellar Universe ; and which we may liken to those artificial lines
of longitude and latitude by which we explain the positions and
movements, equally of near planets and distant stars. Following
Newton's discovery in 1686, of gravitation, the greatest generalisa-
tion the world has yet seen, SirWm. Herschel startled the scientific
world in 1802, with the announcement that amongst the Stars,
binary systems exist, in which the smaller star revolves in circular
or elliptical orbit round the larger. There was no mistaking the
meaning of this discovery. Here was ocular demonstration of
Continuity— viz. : that the same law which causes the apple to fall
to the ground, which retains the Moon in her orbit, and restrains
our Earth from its otherwise headlong flight away from the Sun,
also controls and regulates those giant orbs in remote space.

Up to recent years. Astronomers had assumed certain truths
about the Stars, but were without demonstrable evidence on the
following points : — i. Constitution of the Stars. 2. Are they in-
candescent, and from what does their light proceed ? Are any
Stars motionless in space ; or, in other words, do exceptions exist
in outer space, to that law of Motion in matter, which appears to
obtain throughout the Universe ? In putting these questions to
spectrum analysis, an opportunity now offered of proving or dis-
proving, the continuity, throughout the Universe, of Solar or

238 TIME, SPACE, AND INVISIBLE WORLDS.

Planetary matter ; also the laws to which we know matter to be
subject. The answers which came were definite and complete so
far as they went. i. The Stars are found, as well as the faintness
of their light enables spectroscopists to judge, to be at least par-
tially composed of matter which is identical with that in our Sun
and Earth. 2. The Stars are incandescent, and their light, so far
as ascertained, is also identical with that of our Sun, varying only
according to the prominence of any elements at any moment in
the Star's atmosphere. 3. All Stars, bright enough to respond,
are found, if not by telescope and micrometer, yet by spectrum
analysis, to be swiftly in motion, and to be, just as in the case of
our Sun, all coursing on their mighty journeys, at tremendous
speeds, varying from 20,000 to more than 200,000 miles per hour,
through the fathomless depths of infinite space ; but whither
bound, whether on some vast orbit of trackless extent, or in simple
obedience to the universal gravitation of all matter, no human
being can tell. Here we have another great generalisation, than
which there can hardly be a more conclusive testimony to that
ubiquitous and all-embracing law of Continuity.

In considering the question of invisible worlds, it is necessary
to remember that our Sun is not only a binary but a multiple Star,
that is, a giant centre of lesser stars or planets, which, owing to
the gradual cooling they have undergone during some millions of
years past, have so contracted in bulk and diminished in brightness
that out of the eight primary planets, four— viz., Mercury, Venus,
Earth, and Mars — have become solid and dark bodies ; and the
other four — viz., Jupiter, Saturn, Uranus, and Neptune, although
shining partly by their own light, would yet be utterly invisible in
even the great Lick telescope, if looked for from the distance of
the nearest Star. Even our sun itself, glorious and majestic as he
is, would at that distance sink into a Star scarcely brighter than
Alcyone in the Pleiades Could we plant ourselves upon one of
the globes doubtless revolving round the southern star Phi
in Ophiucus, our Sun would appear from thence as a tiny com-
panion to Aldebaran, half-way towards the little optical double on
its right, and quite possibly the aid of a telescope might be neces-
sary to make it visible at all. In the light of considerations like
these, it would appear to be more than probable that, excluding

TIME, SPACE, AND INVISIBLE WORLDS.

239

nebulous stars and clusters, nearly every naked-eye Star, however
lonely and isolated it may appear, as well as many telescopic Stars,
are the majestic centres, like our Sun, of extensive systems of
planets, satellites, comets, and meteor systems. We must not
suppose, however, that they are all built upon the same pattern, or
that all have arrived at the same degree of development as our
Solar System ; but until Analogy, Probability, and Continuity,
have been proved to be false lights to the human mind in its
search after truth, we must conclude that these globes, while differ-
ing in size, gravitation, brightness, distance, and motion, and yet
resembling each other in general structure and design, all point
with significant force to a oneness in origin, a oneness in purpose,
and a oneness in destiny.

Part II. -INVISIBLE WORLDS IN OUTER SPACE.

By W. D. Barbour.

THE revelations of physiology under the microscope bring us
near to the threshold of the mystery of Creation. We
tread upon wonderful, if not holy, ground. Nature's secret
processes are here unveiled to human gaze. The Divine methods
are made visible. Within that unicellular speck of animal bioplasm,
there lie, as Huxley tells us, "strange possibilities." "In its warm,
watery cradle, rapid changes proceed, yet all steady and purpose-
like, as if in the hands of a skilled modeller. As with an invisible
trowel, the plasma is divided and sub-divided until reduced to an
aggregation of the finest granules. Then, as by a delicate finger,
the spinal column is traced, and head, limbs, and tail, become
moulded in such fashion that one involuntarily imagines the hidden
artist behind it all, working with his plan before him." And our
wonder rises as we read in that jelly-looking speck an amazing
history of mystery. Tracing its ancestry back, in thought, through
countless generations and vast periods of time, which seem- like
eternity, we are confronted at last by our dark cloud-covered Earth,
just cooling down from its primitive sun-like condition. There,
in that lirst bioplasmic " substance, made in secret and curiously
wrought," as it slowly evolves in those warm, saline, nascent

240 TIME, SPACE, AND INVISIBLE WORLDS.

waters, we read, shall we say, the earliest conditions and environ-
ment of organic life, the hidden dawn of mind, its first contact
with Terrestrial matter, and lastly, the first stage in that great drama
of Creation, as revealed in those significant words, "Darkness was
upon the face of the deep, and the spirit of God was brooding
upon the face of the waters."

Noticeable among the characteristics of life, when once it
became established upon Earth, are its immense variety, fecundity,
persistency, and universality. Tyndall speaks of indurated germs
which hours of boiling do not kill. Drummond reminds us of
" the almost incalculable fecundity of the first created forms of
life," and again of a " cloud of progeny of uncountable millions
of spores ; also of common births of a million each, and a mother-
hood in twelve days of sixteen millions of young." Philosophy
has been asking for a thousand years, — " What is the meaning of
all things ? " Revelation long ago solved the mystery in one
word, — " Life." Geology out of its rocky depths of fossilised
organisms likewise answers — " Life." Mountain, lake, plain, river,
forest, desert, ocean, and the air we breathe, each and all respond
with, because full of — " Life." In arctic cold, as well as torrid
heat, we have the same repeated story of — "Life." And the Stars
in distant space are now, in their gentle light, sending us intima-
tions of kinship with Earth and Sun ; in all of which we read a
like end and destiny — the Continuity of Life.

Analogical reasoning has largely forced the conclusion among
astronomers that our Solar system at one time existed as a gigantic
nebula, similar in appearance, and probably in nature, to those
which the telescope descries as bordering on the Milky Way.
Probably homogeneous as an incipient nebula, by what means the
misty primitive matter evolved into separate discrete elements, is
one of the many profound mysteries in Nature. Neither can the
force be explained which originated its rotation, and finally resolved
the nebula into a series of gigantic ball furnaces, hotter by far than
the fiercest heat artificially produced. The final issue, only, we
apprehend in the many " elementary " substances which, sep-
arately or combined, make up the Earth upon which we dwell.
It seems not unreasonable to deduce from these conclusions that
our Planets, being simply off-shoots or detachments from the Sun,

TIME, SPACE, AND INVISIBLE WORLDS. 241

that is, " Samples of the bulk," partake substantially of its nature
and constitution. And spectrum analysis has verified this conclu-
sion to a remarkable extent. Twelve terrestrial " elements,"
including hydrogen (representative of water ; and, although light-
est of all the elements, yet gives three lines in the Spectrum) ;
sodium (the principal metallic base in sea-water), calcium (lime
and limestone rock), and iron ; all which rank among the com-
monest elements on Earth, are found in the Solar spectrum ;
whilst aluminium (the base of clay), carbon and oxygen (essentials
in organised structures), copper, lead, and five other elements, are
believed by Peck, upon strong evidence, also to be present.
Chemists have long suspected substances like carbon, sulphur,
phosphorus, chlorine, and iodine, to be compound and not ele-
mentary ; and the spectroscope has greatly strengthened this
suspicion : indeed, the supposition is neither improbable nor un-
philosophic which would see in every single line of the thousands
contained in the spectrum (with possible exceptions however, as in
the case of Sodium with its double line), the specific evidence of
one single and, perhaps, indivisible element. The present diffi-
culty lies in the frequent inability of the eye to distinguish between
excessively close and fine lines, and the tendency of the terrible
heat of the Sun (Lockyer describes it as " beyond all definition")
to dissociate or break up the so-called elements into finer and yet
finer conditions of matter, the spectra changing with every separate
crisis. It would even seem to be within the limits of possibility
that, given adequate heat, possibly far exceeding that in the Sun,
the final simple element or elements might be obtained which lie
at the foundation of all matter in the Universe. Lockyer expresses
himself thus — "The spectroscopic phenomena observed are simply
and sufficiently explained on the view that the so-called chemical
elements behave after the manner of compound bodies." For
thorough and exhaustive conclusions on the heat, matter, and
general condition of the Sun, his opinion is that its spectrum
should be widened out to the extent of 315 feet.

Turning now to the Stars, and to the answers given by the
spectroscope as to the presence of Solar or terrestrial elements in
all those Stars which were found bright enough to give visible lines,
whilst the evidence received up to the present time scarcely

242 TIME, SPACE, AND INVISIBLE WORLDS.

amounts to demonstration, it yet is significant that all discovery
hitherto tends but to confirm the conclusion that matter in the
Stars is mainly and generically the same as that which is contained
in Earth and Sun. The delay in arriving at just conclusions arises
from the differences existing amongst the Stars, caused chiefly, we
doubt not, by their diff'erences in development and temperature,
the spectra ever changing according to dissociation or combination
of their elements. Many years ago a difference was thought to
have been detected between Sun matter and Earth matter. An
unknown element was detected in the Sun, the lines of which
could not be matched by any substance upon Earth. This new
element was therefore called " Helium," because peculiar to the
Sun. Strange to say, this substance has, within the past year, been
shown by Professor Ramsay to be identical with a hitherto undis-
covered element, existing in some earthy matter which he was
examining. It may here be mentioned that spectrum analysis can
detect the presence of some invisible substances to one eighteen-
millionth of a grain or even much less. Thus, to recognise a new
element as existing in the Sun, 92 millions of miles distant, and
then, after many years, to identify, for the first time, the same
element under our very feet, savours of romance even in science
(justifying the adage that truth is sometimes stranger than fiction),
and is also, to say the least, a curious link in the long chain of
evidence which subordinates all other laws to the greater law of
Continuity.

That no Sun or Star exists to or for itself, we take to be as
absolutely certain as that " no man liveth to himself." All
observation and scrunity of the Heavens, together with analogy,
combine to show a wonderful unity and inter-dependence of Suns
and Planets, existing, so far as we can see, throughout the Universe.
Dark planets we cannot, of course, see ; but, remembering that
our Sun was at one time surrounded by eight brilliant miniature
Suns, now all cooled or cooling down, we understand well what is
meant when the telescope shows us tiny points of light sheltering
under the wings of larger stars like Vega, Aldebaran, Rigel, and
Regulus. Then there are fine double Suns like Castor, a 37 mag.
revolving round the 27 mag. in 1,000 years; Gamma in Leo, a
3-5 mag. round a 2"o mag. in 407 years; Gamma in Virgo, 3*25

TIME, SPACE, AND INVISIBLE WORLDS 243

mag. round a 3 mag. in 185 years, reminding us of our planet
Neptune, which takes 164 years to revolve round our Sun: and
lastly, the giant Sirius, 26 times heavier than our Sun, whose
companion, six times heavier, was believed to exist, owing to
changes in motion of the large star, long before a giant telescope
discovered it in 1862. We may also name Theta in Orion, where
seven Suns, how large no one can tell, owing to unfathomable
distance, lie partly embedded in an enormous nebula ; also the
famous double-double Epsilon in Lyra, the smaller companions
requiring 500 to 1,000 years to revolve round the larger, and each
double perhaps 900,000 years round their common centre, the
two debilissima and two or three others probably also forming
part of the system. Amongst clusters, we have the Pleiades,
2,300 smaller stars controlled by ten or twelve giants; also the
cluster in Hercules, 14,000 suns, all revolving round a common
centre ; and the " Magellanic Clouds " in the Southern sky,
comprising in their 315 clusters and nebulae a galaxy of glory
unimaginable.

• In the above examples, excepting the clusters, it is certain in
some cases, and almost certain in others, that our Sun would be
counted diminutive alongside these colossal luminaries ; also
when compared with such giants as Canopus, Arcturus, Procyon,
Arided, Spica, and Fomalhaut. On the other hand, in crowded
clusters, and amongst the small stars of the Milky Way, we
certainly meet with Suns oi a much inferior order, probably
approaching Uranus in size, say 32,000 miles diameter, or even
small as Earth itself before it had cooled down. Differences in
degree of development are also observed, varying from bluish
white stars, like Vega and Rigel, through middle-aged yellowish
stars like Capella and our Sun, up to red advanced stars, like
Antares and Betelgeux In the law of Continuity we, thus, do
not look for identity of detail or invariable sameness, but rather
for such general variety in size, motion, age, etc., as may consist
with substantial unity in structure and design. This unity, then,
we find to exist between our Sun and the Stars. The Sun is a
huge globe of gaseous and liquid matter, incandescent, emits light,
gives out heat, and is rapidly moving through space. The same
can be said of all the Stars. Elementary matter is also largely the

244 TIME, SPACE, AND INVISIBLE WORLDS.

same in both. A goodly number of the Stars (and probably all)
are also variable like our Sun, but with periods of variability from
a day up to weeks, months, or many years. Gravitation is also
the property of all, binding in one universal bond of union all
Suns, Planets, Satellites, Meteoric, and Cometary Systems.

The above analogies, assisted by probability and unquestioned
knowledge, the result of observation and experiment, prepare us
for the further analogy of " Invisible worlds in outer space." We
refer, of course, to dark solid globes like our Earth. Many
millions of years ago, when the contour of the Heavens was
vastly different to the present, and when our ever swiftly moving
Solar System occupied probably a totally different part of space,
our Sun, younger in years and much greater in diameter than now,
must have appeared to a telescopist (supposing one to be there),
at the distance of four year's light journey, as a large brilliant star,
attended by three or four liliputian Suns, the remaining four
nestling too closely to the large star to be distinguished. But
what appearance would it now present, say, to a telescopist on
one of the Planets revolving round our nearest neighbour. Alpha
Centauri ? All that he would see, in such case, of our glorious
Sun, his splendid retinue of planets, satellites, and millions of
meteor systems and comets, would be a little lonely star in a
vacant portion of Cassiopeia. What then has caused the differ-
ence ? Simply, the cooling down which all have undergone (the
interior four planets having become dark and solid), in the terrible
cold of outer space, with their consequent diminution in size
and brightness. Applying these two illustrations to our present
Heavens, we have the approximate history, past, present, or future,
of all the stars now separately visible to the naked eye, and which
number, on a clear night, about six thousand. Remembering that
these SIX thousand he at all distances from us, from twenty-five up
to a thousand billions of miles or more, we see at once why so
many stars appear as lonely or single. The distances between
them and the Sun-like Planets vanish into nothing from our enor-
mously distant point of observation. Nevertheless, in hundreds
of instances, our telescopes do descry these Sun-like Planets, and
have even traced them in their mighty orbits round their Primaries.
These are the facts, made patent by ocular demonstration, which

TIME, SPACE, AND INVISIBLE WORLDS.

245

go to show that just as our Sun controls dark Planets like Earth,
and bright Planets like Jupiter, so Astronomers reasoning from
analogy and continuity, assisted by telescopic scrutiny, have con-
cluded that the same conditions likewise obtain in the case of the
lucid Stars around us. The argument applies with concentrated
force to those red advanced stars like Alpha Herculis and Mu
Cephei, the greatest portion of whose Planets in all probability
have died down to darkness and solidity long ago.

If further proof were needed, several instances might be named
of short variable stars like Algol, where the darker Sun or Planet,
in the course of its close orbit, actually intervenes between us and
the primary, thus detracting from the latter's brilliancy, and giving
rise periodically to that change in brightness which we character-
ise as variability.

The total number of Stars visible in largest telescopes has been
variously estimated from thirty millions upwards. Of these only
a very small fraction, about six thousand, are separately distinguish-
able by the naked eye, under favourable circumstances. Those
of first and second magnitudes are undoubtedly much larger than
our Sun, and, in some cases, as much larger as our Sun is than
Jupiter. How many are smaller, it is not possible to say ; but
being certain that a considerable number of the lower magni-
tudes, like some in the Pleiades, appear so, only by reason
of their enormous distance, we may not err, perhaps, if we
regard each of these six thousand as, on an average, equal in
bulk to our Sun. Let us also assign to each an average
of eight primary Planets, as in our System, thus giving a total
of 48,000 Planets, in addition to attendant Satellites, Com-
etary Systems, etc. Half of these 48,000 we will suppose to be
incandescent like Saturn, and the remaining 24,000 to be dark and
solid like Earth, Mars, Venus, and Mercury. Let us now divide
this number, as a tribute to the majority of Sirian or " young "
Stars, also to any faint Stars whose light may have become dim,
and whose heat dulled, through age ; and whose planets, therefore,
may have already passed the life-bearing stage ; and also as an
allowance for any planets which, owing to excess or deficiency of
heat and light, or other cause, have proved incompetent for the
development of life. We thus arrive at twelve thousand dark

246 TIME, SPACE, AND INVISIBLE WORLDS.

and, to all appearance, inhabitable planets. Ignoring for the
present Mars, Venus, and Mercury, and taking Earth only as our
guide in analogy, let us regard every fourth globe only as inhabited
by organised life, short of Man. We are thus left with three
thousand Planets controlled by Suns within the limits of naked
eye vision, in which, according to all available evidence, furnished
by Analogy, Probability, and Continuity, life, vegetable and animal,
exists more or less abundantly.

The question now arises (and the answer will surprise those
who have not considered the matter), " In how many of these
three thousand worlds may we reasonably suppose the evolution
of life to have culminated in responsible and intelligent beings
like ourselves ? " This question is answerable only by asking
another, "When did the life-bearing stage commence upon Earth?"
Even Geology, with all its wonderful discoveries, fails us here.
Authorities vary in their estimates, but all speak of millions of
years. Shall we say, just to give point to thought, not less than
seven, more nearly twenty, and just possibly forty millions, these
being followed by the small fraction of seven thousand years cover-
ing human probational history ; that is, the history of Man as the
final product of physical evolution, he alone combining within
himself all the tremendous issues of the past of Earth, with all the
possibilities of an illimitable and evolving future. These figures,
which, if the reasoning be just, or approximately so, by no means
exaggerate the final result, indicate, by the following simple ratios,
the number of planets now inhabited by human or intelligent life,
and now controlled by those Star-suns which the naked eye can
descry on any clear night in the Heavens above and around us.
The total life-bearing period of each planet (continuing for seven,
twenty, or forty millions of years) is to the total human life period
(say seven thousand years), as the number of present life-bearing
planets (three thousand, as before named) is to the number of
planets now inhabited by intelligent beings like ourselves. The
ratio or answers are as follows : — 3 planets, if the average life
period of the 3,000 be 7 million years ; 1-05 if 20 millions ; and
o'525 if 40 millions.

Thus, by calculation based upon averages, supported by
analogy, probability, and continuity, we reach the singular result

TIME, SPACE, AND INVISIBLE WORLDS. 247

that out of the 48,000 planets controlled by Suns visible to the
naked eye, only three thousand can reasonably be regarded as
inhabited at the present time by vegetable and animal life, short
of man ; and that only the very small average fraction of i'525
(that is, less than two) can fairly be looked upon as the present
abode of moral and responsible creatures like Man. These figures,
it will be noted, do not touch our conclusion that the 48,000 plan-
ets referred to, pass, with probable exceptions, arising from various
causes as already named, through the life-bearing stage at one
portion or another of their histories.

Instead of limiting the enquiry to the six thousand Suns, which
our unassisted vision can distinguish on a clear night, let us extend
it to that vast multitude of Stars which lie within the reach of our
largest telescopes and most sensitive photographic plates. Estima-
ting these at the modest number of twenty millions, we obtain, by
the same process of calculation, a residual of ten million worlds
inhabited by inferior animal life, and 5,083 inhabited by moral
and intelligent life, similar to our own.

• The argument for worlds of life in outer space is well summed
up in that epitomised history of Creation, which fitly stands at the
head of the noblest revelation given to man. In its veiled sen-
tences, the student will find, in simple and majestic language, not
only the beginning of all Earthly things, but in stately order, and
in measured pace, the unfolding of the Divine plan, and finally,
the secret told, the why and wherefore of it all — the evolution of
man. As in matter, we read the spiritual made manifest, so in
man we read matter made spiritual. In the light of this ancient
story, the immediate end, the object of the invisible worlds in
space, whatever be their ultimate destiny, stand revealed. Like
our Earth, they are the homes in which are born — the nurseries in
which are taught — the schools in which are trained, often "through
much tribulation " — the children of God.

[ 248 ]

preservation of UIqx.

ACCORDING to W. A. Setchell and W. J. V. Osterhout, the
selection of aqueous media for preserving algae for class pur-
poses is a matter requiring careful consideration. They
find, too, that no one medium can be used indiscriminately for all
kinds of material. The Cymiophycece are best prepared with a solu-
tion containing i per cent, each of chrome alum and formalin.
The gelatinous sheath and matrices are rendered firm by this
solution, the cell contents are kept in a very natural condition, and
in most cases the colours are retained in their ordinary tints. For-
malin solution, I to 2 per cent., preserves the cell contents very
well, but does not preserve the colours or the softer gelatinous
sheaths and matrices. Camphor water fails with many blue-greens,
and is not strong enough for species preserved in the mass and
associated with many bacteria. The Chlorophycece are very satis-
factorily preserved in any of these media, but chrome alum is
preferable in most cases, though membranaceous forms — li^e Ulva
lactena, etc. — are rendered very brittle, and are, therefore, better
placed in simple formalin solution. The Phceophycece. do well when
placed immediately in r per cent, chrome alum for three to six
hours, and then preserved in 2 per cent, formalin solution or
camphor water. Specimens for crushing may remain indefinitely
in chrome alum solution. The coarser forms of the Rhodophycea.
may be kept in excellent condition in any one of the three solu-
tions recommended, chrome alum preserving more colour than
formalin or camphor water. For finer study, specimens are best
left in a concentrated solution of picric acid in sea-water for twenty-
four hours, then washed in plain sea -water for twenty- four hours
longer, and preserved in camphorated sea-water.

Such genera as Nemalion, Chai?ipia, Rhabdoma, Cystodoniiim,
etc., respond best to this treatment. Delicate species, like Grtf-
fithsia bornetiann, Calithamtiion baileyi, C. bot'reri, C. seirospermum,
etc., must be placed in 2 per cent, formalin in sea-water, with
plenty of fluid, so as not to be crushed, and though the colour
disappears, the cells keep their shape and the plants present a life-

PREDACIOUS AND PARASITIC ENEMIES OF APHIDES. 249

like appearance so far as form goes. To prevent Dasya elegatis
dropping its hairs, and the more delicate species of Polysiphonia
breaking up into short pieces, they should be put, whilst fairly
fresh, into formalin or chrome alum solution. — Bot. Gazette.

|pre^aciou6 S. iparaditic lEnemice of apbi^c0

(incluDina a StuDy oX H^^per^parasites).

By H. C. a. Vine.
Part IV, (continued). Plates XIII. and XIV.

Capsus Lanarius. Anatomy of the Imago.

THE change involved in the casting of the nymphal skin of
this specie^ is much greater than is the case with many
others of the order. The most striking feature of the
nymph, the numerous tufts of elongated, flattened appendages,
which, for want of a better name, I have called ' hairs,' have
wholly disappeared, and the abdomen, which has no longer the
distended appearance of the nymph, is become chitinous, shining,
glabrous, brown to black in colour, though sometimes yellowish
beneath, and clearly segmented ; in the female the dorsal surface
of the posterior segments of the abdomen is divided by two horny
ridges, between which an ovipositor of beautiful construction
(Fig. 6, PI. XIV.) is extruded as occasion requires.

The abdomen and the major part of the thorax is now com-
pletely hidden by the extensive hemelytra, which, with the evolu-
tion of the scutellum and the development of colour, make so
great a change in the general appearance of the insect as to make
it difificult to believe that only a cast skin stands between it and
the nymph.

The Head of the Imago.
The head has wholly lost the elongated and somewhat
angular appearance which was characteristic of the larva. It is
now broad and flat, the length at the most not exceeding the

International Journal of Microscopy and Natural Science.

Third Series. Vol. VI. r

250 PREDACIOUS AND PARASITIC

width between the top of the eyes, and the entire width being as
nearly as possible two and a-half times the length. The projection
of the labrum is much less obvious than in the larva, no doubt
from the modification in the proportions of the parts ; the differ-
entiation of the ' face ' into the central lobe and the gence, or
cheeks, is generally well marked, and the attachment to the frontal
thoracic segment — the pionotion — is by means of a narrow collar.
The surface is smooth, impunctate in all specimens I have seen,
free from hairs or bristles, and varying in colour from black to
reddish brown and ochreous yellow.

The Antenna.

These organs are equal to or exceed, in length, that of the
entire insect, and are strongly characterised by the contrast between
the anterior and basal joints. The substantial first joint is about
one-eighth to one-tenth the length of the entire organ, and is
slightly inflated rather in advance of its centre ; it is approaching,
or quite, black in colour, and is fairly covered with rather long,
thin hairs of ordinary structure. The second joint occupies fully
one half of the entire antenna in average specimens. It is towards
the base narrow, rigid, and very distinctly black ; the central
portion in pale specimens is usually yellow, and in dark specimens
nearly black, and increases somewhat in size towards the final
portion, which is enlarged and ends with a square shoulder, and
has a slightly domed transverse termination. The whole of the
joint is regularly clothed with stiff, fine hairs of ordinary structure,
partaking usually of the colour of the derma, from which they
rise ; towards the thickened end they become much more dense,
and are also slightly longer and stouter ; the colour is here very
black.

The two final joints are together about three-fourths the length
of the second joint. 'I'hey are parallel-sided and are considerably
less in diameter than the preceding joint at its narrowest point,
sparsely clothed in fine even hairs, which differ considerably from
those found in the same situation in the nymph. The colour of
these segments varies in different specimens from yellow to brown
or black ; the final joint is usually about two-thirds the length of
the third joint, which it otherwise resembles in every respect.

ENEMIES OF APHIDES. 251

The total length of the antennae averages about one-fifth of an
inch.

The Rostrum.

This organ serves its most important uses in the earlier stages
of the life of the Hemipteron, and in the imago is, in proportion
to the remainder of the insect, distinctly smaller than it was in
the fully-grown larva or nymph. It consists of the various organs
already described in the last part, and is in frequent requisition
for the piejcing of aphides.

The Thorax.
The thorax is,- to a great degree, hidden in all Bugs by the
hemelytra. The pronotum (the dorsal aspect of the anterior seg-
ment) in Capsus lanarius is exceedingly narrow in front, not much
exceeding the width of the head between the eyes, and wide
behind, the sides sloping very sharply. It varies in colour from
black in dark specimens to yellow in some pale ones, and is closely
punctured over its entire surface.

• The scutellum, which is the only other portion of the thorax
visible when the hemelytra are closed, is of medium size, almost
equilateral and domed. The colour varies from black to yellow,
and the surface is rather sparsely punctured with finer punctures
than the pronotum and elytra. Beneath, the coxae, the large size
of which is characteristic of the genus, are the most obvious features.

The Hemelytra and Wings.
The coriaceous portion of the hemelytra is well developed in
C. lanarius. From the point of attachment to the mesonotum to
about three-fourths of the entire length of these organs they are of
a thick horny structure, in which the ridges separating the various
parts are very prominent. This portion is thickly and deeply
punctured, but otherwise somewhat shell-like in texture and
without hairs except at the apex. Each hemelytron consists of
corium, clavus, cuneus, and membrane. The cuneus is separated
from the corium by a deep indentation, a trace of which is pro-
longed across its width, giving the apical portion an appearance of
almost separation. The cuneus is sharply pointed at the exterior
edge, and is here almost black ; above which is a patch of bright

252 PREDACIOUS AND PARASITIC

scarlet, the colour gradually losing its intensity as it recedes from
the apex, which is covered with fairly thick black or brown hairs.

The membrane beyond the coriaceous portion, forming about
one fourth of the entire length of the organs, is very finely rugose,
blackish or brown in colour, usually with a light or clear patch
below the final extremity of the coriaceoivs portion. It is strength-
ened by a thick nervure, extending in an oblong loop from one
ridge of the corium to another, and the space enclosed is divided
into two unequal cells by a similar nervure traversing it longitu-
dinally. Some part of these nervures, which appear to be con-
tinuous with the substance of the corium, are often almost as
brilliant in colour as the cuneus. The hemelytron is shown,
sufficiently amplified for these details to be readily seen, on PI.
VIII., at Fig. 4, in our last chapter.

The membranous posterior wing, which is only visible when
the insect is about to take to flight and the wings are expanded,
resembles in many respects the corresponding organ among the
Coleoptera, (although of course without provision for folding
transversely) as may be seen by a comparison of the drawing.
Fig. 5 on PI. VII., with that of CoccineUa bi-pundata, delineated on
PI. VIII. of the previous volume ; but the arrangement of the
nervures is different in the various families, and although in the
Capsidce the projecting hook-like development of the nervure
forming the upper side of the cell, which is found in some genera,
serves for a sectional division, it is not always to be depended
upon, as it is sometimes scarcely developed, and in one family,
which I have not had an opportunity of examining, is stated to be
sometimes present and sometimes absent altogether. The mem-
brane is covered evenly, but not quite closely, with short, regular
hairs, and is fringed with very fine hairs of somewhat greater
length, which, along the nerve which forms the upper edge,
assume the appearance of very minute short spines.

The Legs of the Imago.

The last appendages of the thorax to be noted are the legs,

which afford some useful features for generic division in the

Capsida. The coxse in this family are generally very much

developed, and the tibiae are sometimes furnished with spines at

ENEMIES OF APHIDES. 253

regular intervals, as in Plagionathiis and Orthocephalus, which are
characteristic. The tarsi are three-jointed.

The Abdomen of the Imago.
The abdomen in the Capsida is much softer in its structure
than is the case with most other families of the order. In Capsus
lanarius it is somewhat short and fairly wide ; the number of
segments which may be readily observed does not exceed eight,
but the generative segments comprise the representatives of two or
three other segments, so that some of the best writers on the
Hemiptera give the total theoretical number of segments as eleven.
In Capsus the females are provided with a beautiful and strangely
constructed ovipositor, contained, when retracted, within a groove
formed by a pair of horny ridges on the under surface of the
abdomen. In the male, the only external evidence of the organs
of generation consist of a pair of " genital styles," which are found
at the extremity of the abdomen.

The Ovipositor.

This organ consists of four chitinous blades, somewhat broad
and 'short, slightly curved and widened towards their points, some-
what after the shape of a flat spear-head. The organ is figured on
Plate XIV., at Figs. 6, 7, and 8. The two outer blades, a and b, can
scarcely be said to form a sheath for the stronger blades within them,
but it is more probable that they fulfil the part of lancets, and
pierce the surface on or in which the egg is deposited, leaving the
central blades only the function of passing on the egg.

Both pairs of blades are strengthened by a narrow chitinous
rib, and towards their extremities the lancet blades are finely ser-
rated on the outer surfaces, giving to the edges the appearance of
a saw. In C. lanarius also several larger teeth, independent of
the serration, are visible on the outer edge, but these I have not
observed in any of the other species, which are furnished with a
similar ovipositor. The central ribs, which give the necessary
rigidity to the ovipositor proper and to the lancets, coalesce in
pairs at the base of the organ, and joining beneath it, so as to
form a ring, through which the base of the ovipositor proper is
attached to its muscular supports, they continue into the lateral

254 PREDACIOUS AND PARASITIC

parts of the abdomen, where they are attached to the various
muscles by which the parts of the organ are actuated. The action
of the outer lancets appears to be of a rasping rather than a cut-
ting nature, and as, in the instances of which I have definite
knowledge, the eggs are placed upon the surface of leaves, it seems
likely that the function of these organs is to roughen the surface,
or to irritate it, so as to render it fit for the reception of the eggs.

The Internal Anatomy.

The alimentary organs are of a much simpler type than obtains
in those insects which have been hitherto described in these pages.
The suctorial tube of the rostrum passes on the juices which it
has extracted from the victim through a pharynx surrounded by a
mass of spiral muscles to an oesophageal passage, which receives
in its course the secretion of two or four attached glands, which
may be presumed to be salivary in their functions. There is no
organ in any way analogous to the sucking stomach of the diptera,
but the juices pass directly to an elongated vessel which answers
the purpose of stomach and intestine, but in which it is difficult to
allocate the limits of the respective functions. Some vessels dis-
charge into this organ at a point which is probably the termination
of the stomach proper. It has been suggested by Burmeister that
these are of a urinary nature, but from their position and structure
in the specimens, which I have examined, I should be more
inclined to think they may be biliary in function, if I ventured to
differ from so responsible an authority on insect anatomy.

The intestine terminates in a short, slightly expanded tube,
which opens at the extremity of the abdomen, forming the anal
orifice. In the female the sides of the abdomen are occupied by
the ovaries, in which the elongated eggs lie clustered in an oblique
position, ready for their passage to the ovipositor. I have always
observed that the ova are all about the same size and apparently
equally developed, while I have not found any appearance of
immature or rudimentary ova which, by successive development,
would keep up the supply. From this it would seem that the eggs
of these insects must be comparatively few in number, and that
the first development of the ovaries probably represents the extent
of the maternal effort. The spermathecse which are mentioned by

ENEMIES OF APHIDES, 255

some writers have escaped my own observations ; but the analogy
which the organs present to those of other insects renders their
existence pretty certain. The male generative organs may, in a
good specimen, sometimes be traced lying along the central part
of the abdomen, and consist of testes with subsidiary glands, and
a narrow canal with an ejaculatory duct ; but the parts are so
fragile and difficult to observe in juxtaposition that I could not
make a reliable drawing. The remaining internal organs follow
closely the lines found in other nearly related insects, and do not
present many features of special interest.

The second aphidivorous genus of the CapsidcB is Plagio-
nathus (Fieb.), which includes nine species found in Britain.
Several of them are figured on PI. XIII., and it will probably be
found that most of them are occasional, if not habitual, Aphis-
eaters. They are generally narrow and oblong, and are distin-
guished from other genera, having a similar hook-like projection of
the nervure in the membranous wing, by the presence of all the
following features : — The tapering antennse, black or dark-brown
spots or spines, or both, on tibise, and a glistening surface clothed
with short, fine black or silvery hairs.

The species are very widely distributed, and some, including
P. arbtistorum, the known aphis-eating variety, are very common.
P. arbustorum may often be found upon nettles, but wild cornel,
angelica, red currant, and rose, at times all become its temporary
habitat, and probably many other aphis-haunted plants are visited
by it. Mr. Watkins has communicated to me his observation of
the presence of the imago on Angelica in mid-winter, and there is
no doubt that it frequently hybernates in sheltered situations. The
aspect of the insect varies very considerably, it being variously
described as ranging from almost wholly black to dull yellow. I
have myself seen none but ochreous yellow specimens, some
having more black than others ; but in all, the black margins of the
light-coloured femora and two first antennal joints suffice to iden-
tify the species.

Mr. Saunders tabulates the species as follows : —
I, — Vertex with a distinctly raised carina, antennse
short, with second joint longer than third and
fourth together ... ... ... Roseri.

256 PREDACIOUS AND PARASITIC

2. — -Vertex without a distinctly raised carina, third
and fourth joints of antennae together longer
than the second.
3. — Male more parallel-sided and elongate than the
female, femora pale, spotted or lined with black,
or surface clothed with silvery white hairs.
4- — Surface clothed with silvery hairs ... ... Albipennis.

5- — Surface not clothed with silvery hairs.

6. — Femora margined with black ... ... Arbustorum.

7. -Femora spotted at apex, but not margined with

black ... ... ... ... Viridulus.

8.-— Male and female, nearly alike in shape, femora
dark or red, upper surface not clothed with
silvery hairs.
9. — Spines of tibiae strong and black, arising from
black spots.
10. — Base of corium pale ... ... ... Bohemani.

II. — Elytra entirely dark.

12. — Larger, a pale spot near each eye ... ... Nigritulus.

13. — Smaller, head entirely black ... ... Pulicarius.

14. — Tibiae, with fine black spines not rising out of

black spots.
15. — Base of the elytra pale ... ... Saltitans.

16. — Base of elytra concolorous with the rest ... Wilkinsoni.

P. albipennis, P. arbustorum, and P. viridulus are the com-
monest species, and I think it likely that all are aphidivorous,
though definite proof has only been obtained in regard to the
second species. I have been unable to secure any specimens
which could be certainly identified as the larval and nymphal
stages of P. arbustorum, but the imago is shown on PI. XIII. at
Fig. I. The antennae and the characteristic tibiae are given on
PI. XIV. at Figs. I, 2, and 3.

The colour of my specimens, as I have already mentioned, is
ochreous throughout, with some points of deeper orange, and
hairs, spines, parts of antennae, etc., black or very dark brown.
The external anatomy of the imago differs in some important
respects, besides the more elongated shape, from the Capsid last
considered, and the following points are of interest : —

ENEMIES OF APHIDES. 257

The Head.
The head is of average proportions, with a prominent labrum,
of a black or dark colour as far as a line drawn across behind the
eyes. Behind this is a band of lighter colour, greenish grey to
yellow. The surface is clothed with fine hairs, and a number of
long, coarse black hairs, almost bristle-like in texture, are very
obvious. In common with the other genera of this family, the
ocelli are wanting ; but the perfect development of the eyes is a
characteristic feature. The eyes stand out on either side of the
head like two spheres attached to it by about two-fifths of their
surface only ; the facets are large and very clearly defined, and
regular to the edges of the organs, and on the posterior side, where
in many species the lenses fade and the pigment is deficient, both
are in P. arbustorum as sharp and perfect as elsewhere, except on
a small, clearly-defined, semi-circular space next the pronotum,
where they are altogether absent.

The Rostrum.
This organ, which is four-jointed, differs little from that of
C. lanariiis, already described, but the basal joint is more volumi-
nous and of a more chitinous texture.

The Thorax and Wings.
These structures also present much the same features as in the
Capsid already described. The Hemelytra are considerably longer
and narrower, and are clothed, as to the coriaceous part, with
short, fine black hairs, which frequently appear silvery in reflected
light. The membrane is dark, with a translucent spot behind the
cuneus.

The Legs.
The most characteristic features of the species are to be found
in the femora and tibiae, the former of which are always outlined
and sometimes spotted with black or very dark brown. The
tibiae are pale, usually ochreous, and provided with a number of
fine black spines, each of which rises from a patch of brown upon
the integument ; the extremities of the tibiae and the whole of the
tarsi are also black.

258

PREDACIOUS AND PARASITIC

Among the Cimicidce, one sub-family, the Anthocorid(B, is pro-
bably the best-known of the Aphis-eating Hemiptera.

The Cimicidcz comprise four sub-families, and probably a car
nivorous habit prevails throughout the group to a greater or less
degree. The following characters, given by Saunders, will enable
the student to determine to which division any detected aphis-
eater may belong : —

I. — Rostrum 3-jointed, tarsi 3-jointed.

2. — Ocelli absent ...

3. — Ocelli present.

4.— Antennae very long and thin, clothed vvith long

hairs, third and fourth joints together twice as

long as first and second
5. — Antennae not very thin, not clothed with long

hairs, and third and fourth joints not nearly

twice as long as the first and second
6.— Rostrum 4-jointed, tarsi 2-jointed

Cimicina.

Ceratocombhia.

AntJiocorina.
Microphysi?ia.

The sub-family, Anthocorina, includes eleven genera found in
Britain : —

I. — Third and fourth joints of antennae very fine

and thin, clothed with long, erect hairs.
2. — Anterior femora, hardly thicker than the

intermediate pair .. ... ... Lydocoris.

3.— Anterior femora incrassated, much thicker

than the intermediate pair ... ... Piezostethus.

4. — Third and fourth joints of the antennae,

scarcely or not thinner than the preceding,

hairs, not long and erect.
5. — Cell of the vving, with a hook-like nerve.
6. — Pronotum, with a distinct apical collar.
7. — Apex of the metasternum between the coxae,

widely truncate.
8.— Rostrum, reaching to the intermediate coxae.. Temnostethus.
9. — Rostrum, not reaching beyond the centre of

the mesothorax •• ... ... Elatophilus.

10. — Apex of metasternum, rounded and narrower.

ENEMIES OF APHIDES. 259

II, — Rostrum short, hardly reaching beyond the

anterior coxae.
12. — Apical collar of pronotuni long, sides gra-
dually diverging from it ... ••• Anthocoris.
13. — Apical collar short, sides widely rounded

behind it ... ... ... ••• Tetraphleps.

14. — Rostrum, reaching to intermediate coxae ... Acompocoris.

15. — Pronotum without a distinct collar ... Triphleps.

16.— Cell of the wing without a hook-like nerve.

17. — Species robust, pubescent.

18. — Head short, scarcely longer than its width

between the "eyes ... ... • Brachy steles.

19. — Head much longer than its width between

the eyes ... •■. ••• ■•• Cardiastethus.

20. — Species elongate, glabrous, parallel-sided .. Xylocoris.

Of these genera, the first, Lyctocoris (Hahn.), is certainly car-
nivorous, preying upon the small insects found in the rubbish
which forms its usual habitat, and I have strong reason to think
that the second Piezosiethus (Fieb.) is not only an insect-eater, but
an aphis-eater, attacking the melon aphis and other species which
are found in the hot beds which it usually haunts. Its habits in
this respect render it a very convenient species for study.

Anthocoris (Fall.). — The genus may be readily recognised by
the following characters : — Head with eyes not touching the pro-
notum ; ocelli placed posteriorly, close to the inner margins of the
eyes ; antennae with second joint not nearly so long as the third
and fourth together; rostrum short, reaching to about the anterior
coxae; pronotum, with well-marked apical collar, sides behind it
more or less rounded, base largely sinuate ; scutellum impressed
at the apex ; ' elytra always developed, their sides sub-parallel or
slightly rounded ; legs simple, posterior coxae close together, the
metasternum produced between them in narrowly rounded lobe.'
Six species are known as British and may be distinguished as
follows : —

I. — Elytra in part dull.

2. — Corium entirely shining, except at the

extreme base ... ... ... Sarothatnni

( Douglass & Scott. )

260 PREDACIOUS AND PARASITIC

3. — Corium dull except towards the apex .. Gallarum ulmi

(De Geer.)

4. — Corium entirely dull.

5. — Cuneus entirely shining ... ... Nemoralis.

(Fabr.)

6. — Inner angle of cuneus dull.

7. — Larger, head and pronotum black ... Confusus.

(Reuter.)

8. — Smaller, head and pronotum in front red ... Visci.

(Douglass.)

9. — Elytra entirely shining ... ... Sylvestris.

(Linn.)

Probably all these genera are carnivorous and aphis eaters, and
it will be observed that each species haunts plants or shrubs which
are usually frequented by aphides in great numbers. A. sylvestris
is well known to the hop growers as a frequent visitor on their
limes, but they are far from recognising its beneficent mission, as
they very generally believe it to be injurious to the vegetation. If
the hop farmers had studied the matter with as much interest
as they bestow upon the liquids with which they endeavour
to destroy the aphides by " washing," they would have discovered
that the " needle-nosed fly," as they call it, is an active ally, and
passes its life destroying the aphides which really do the mischief,
which the farmer attributes to the bug.

I have frequently seen A. sylvestris transfix a juicy aphis (and
it appears to me to exercise some discretion in this respect), and
after the gentle, or violent, as the case may be, insertion of the
lancets of its rostrum, to remain motionless, save for the rhythmical
movement due to the pumping action of the muscles, while the
aphis, sometimes quiescent and sometimes struggling, collapses
gradually, and is often at last lifted, an almost empty skin, upon
the rostrum of the attacker, to be presently contemptuously cast
aside, though still with the ability to feebly use its legs and move
away. Mr. C. J. Watkins has kindly informed me of several sim-
ilar instances, and Mr. Maclachlan in the Ent. Proc. remarks on
its activity in attacking Aphides in the hop gardens. I have figured
A. sylvestris on PI. XIII., at Fig. 2, and also the immature larval
form at Fig. 3. The characteristic hemelytron and antenna are
shown, along with those of P. arbustorum, on PI. XIV., Figs. 4 and 5.

ENEMIES OF APHIDES, 261

The most characteristic details shown in these figures will
enable the reader to appreciate the main features of difference
between this genus and those already described and figured without
the wearisome repetition of detailed description. The colouring
is always more or less dull, and partakes of yellow, brown, and
black, and the general aspect of the insects, especially as to the
head, is somewhat long and pointed in comparison with Capsus,
and, though not so narrowed as Plagionathus, the head of the
latter is much more obtuse.

To facilitate the recognition of other species of the genus as
aphis eaters I have drawn also on Plate XIII., figures of ^. nemo-
ralis, A. gallarum ulmi, and A. visci.

The development of the Hemiptera-Heteroptera is still very
obscure, and, in view of the difficulties in the way of investigation,
nothing short of an exhaustive study of the whole subject with the
advantages of a suitable insectary and other conveniences will
avail to put us in possession of the consecutive phases of these
insects' history. I myself have made many attempts during the
past two years to observe the development, but have been met by
great difficulty in obtaining eggs which had any reasonable cer-
tainty of being those of the insects in question. The ordinary
sources of supply appear unable to provide eggs of plant bugs, and
they seem to be very rarely observed on vegetation, while I have
never known the female produce eggs in confinement.

So far as I can judge from fragmentary observation, the eggs
are laid about the middle of spring, and it is some weeks fre-
quently before the young are hatched. The eggs are elongated,
and are attached usually to vegetation in layers or groups, the
upper or free end having some sort of ridges or spines around it,
and the colouring varying from quite pale to a deep brown. The
young, on leaving the egg, shows little of its ultimate shape, this
only developing when the first moult takes place, which is some
fourteen or fifteen days after its emergence from the egg, and
seems to depend upon the supply of food. Meanwhile, a small
oblong insect, considerably wanting in development, except as to
its rostrum, is the larval representative of the future Hemjpteron.
After the skin is first cast, some of the recognised characters of
the sub-order become apparent, and it is in some cases possible

262 PREDACIOUS AND PARASITIC

(as in the case of C. lanarius) to say to what family the larva
belongs. The carnivorous species, during their earlier existence,
are chiefly dependent upon their vegetable hosts for their
nutriment ; but after the moult more frequent attacks upon
Aphides, and other small insects, may be observed, even in
confinement ; and I have noted that, when so kept, recurrence to
vegetable juices is much more general than when the insect is in
its natural habitat. Some three to four weeks is the apparent
duration of the larval condition, and at this time the insect dis-
appears from its ordinary haunts, and, hidden in some deep
crevice, divests itself of its larval envelope, appearing again with
the wing-pads and developments of detail of the nymph or pupa.
So well does the insect conceal itself at the time of change that I
have never succeeded in finding a cast skin.

The nymph is much more sturdy (in C. lanarius^ which has
been the principal subject of my observations) and rapacious than
the larva, and frequently accounts for a considerable number of
Aphides — always, I think, in the larval form — in a short space of
time.

A specimen taken in the nymph stage, after a short time,
during which it appeared anxious to escape, attacked and consumed
three aphis larvse in the course of forty-five minutes. The period
of existence in this stage seems very uncertain, and probably
depends upon the atmospheric condition and the supply of food.
Certainly, a very large proportion of the immature Hemiptera
which I have taken from time to time are nymphs. A few days
may sometimes see a change to the imago condition, but I have
had a Capsid under observation for three weeks, and lost it without
any development taking place.

With the final moult the voracity of the insect becomes much
reduced, and it may now be more often found on plants which are
not usually frequented by Aphides. The characteristic features
also for the first time become clearly defined, and the modification
in the number of joints in the antennae, the rostrum, and the tarsi
form valuable specific and generic indications.

The females of the Capsidce and of some other groups which
are similarly furnished with an obvious ovipositor are beautiful
objects for microscopic study. The eggs are usually laid in rows

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ENEMIES OF APHIDES.

263

or groups on leaves, or in many cases underneath bark, and pro-
bably, I think, in this latter situation survive the winter, though,
as I have seen specimens of Capsus hybernating in December and
January, there can be no doubt that some of the mature insects
survive until spring to perpetuate their race.

The highly destructive system of the insect world is well seen
in the vast proportion of the eggs of bugs which are pierced and
destroyed by parasitic Hymenoptera. So much is this the case
that it is very uncertain if a cluster of eggs will yield a single
Heteropteron larva, their place being taken by minute Hymenop-
tera of similar species to those which we shall later on review as
the chief destroyers of Aphides.

EXPLANATION OF PLATES XIII. AND XIV.

Plate XIII.
Fig- 1 • — Imago of Plagio7iathus arbustorum.
2. — Larva of Anthocoris sylvestris.
3. — Ima^o of same.

4.

P. roseri.

5.

P. albipennis.

6.

P. saltitans.

7.

P. bohemanni.

8.

A. nemoralis.

9.

A. gallarum ulmi.

10.

A. visci.

11.

Podisus luridus.

Plate XIV.

Fig. 1. — Antenna of Plagionathus arbustorum.

,, 2. — Hemelytron of same.

J, 3. — Tibia and tarsus of same, exhibitina; characteristic
markings and spines.

,, 4. — Antenna of Anthocoris sylvestris.

,, 5, — Hemelytron of same.

., 6. — Ovipositor of CVi^wiw lanarins, in situ (from a balsam
mcjunt).

,, 7. — Ovipositor, separated.

,, 8. — One of the external blades or sheaths.

[ 264 ]

^ecbnolog^ of Biatoms,*

By J. Tempere.

Chapter III.-ON THE MOUNTING OF DIATOMS.

DIATOMS prepared as I have described in the preceding
chapters are mounted in two ways — either dry or in a
medium. These two methods apply equally well to mixed
Diatoms — that is to say, to washings spread out on a thin plate —
as to species that are sorted and isolated.

The Dry Method.

The mounting of Diatoms dry is the less used of the two
methods ; it requires more care and more attention than when a
liquid is used, for it is necessary to exclude all trace of moisture in
the cell and also to prevent its subsequent introduction.

Preparation of the Cells. — The cells should be made of a
cement of black gum-lac, prepared as follows : — In a vessel of tin
(a sardine-tin will do very well) you heap up white gum-lac to half
its depth, and having made a saturated solution of aniline black
in alcohol of 90^ (absolute alcohol), pour enough of it over the
gum to cover it ; allow them to remain in contact for a few
minutes, and then place the tin in a water-bath, stirring the
mixture till the lac is completely dissolved ; then, while warm, pass
the mixture through muslin. In cooling, this cement becomes
semi-liquid, and has just the consistence which it ought to have to
meet the requirements of the operation. When, in consequence
of the evaporation of the alcohol, it becomes too thick, a few
drops of absolute alcohol may be added, taking care that it is
well stirred up.

The cells — which ought to be made on the turn-table — should
have always the same exterior diameter as the thin glass which is
to cover them ; their thickness may vary from the i/8th to the
i/ioth of a millimetre. One good coat of cement is generally
enough.

In order to make a good cell — that is to say, one that is not
too large and of even thickness throughout — it is well to use a
sable brush of the best quality, of which the hairs are not more
* Translated from Le Diatomiste.

TECHNOLOGY OF DIATOMS. 265

than ten millimetres long. These cells ought to be prepared a
good while in advance, so as to be perfectly dry and hard when
they are wanted for use. Those of our readers who have a stove
can accelerate the drying by placing the cells near it for a few
hours.

To Spread the Diatoms Uniformly over the Thin Glass.

The Diatoms intended to be mounted dry ought to be held in
suspension in distilled water, absolutely pure ; that is to say, that
when evaporated on a thin glass, it shall leave no trace behind.
If they have been kept in eau-phe7iique or in alcohol (marine
gatherings), these liquids ought to be entirely got rid of.

And here a little difficulty occurs which tact and practice will
soon surmount ; it refers to the quantity of Diatoms that ought to
be contained in two or three cubic centimetres of distilled water,
so that when once spread on the thin glass there shall be enough
without their being superposed one on the other, or allowed to
form into little masses, as frequently happens with the smaller
species. As a general rule, you may say that the water containing
the Diatoms in suspension should never have a milky appearance,
but only a slightly opaline tint, especially when the small species
are concerned. As to the medium-sized species and those still
larger, it is desirable to see them individually float in the liquid.

The glass on which we are to spread the Diatoms ought to be
thin glass (English No. i), perfectly cleaned, for the least trace of
greasy matter will cause an immediate retreat of the liquid, and
the even spreading of the Diatoms will be rendered impossible.

I always take the precaution, in order to avoid this difficulty,
to use new English glasses, which are cut mechanically and put up
in i-oz. and \-oz. boxes, and have not been handled. These can
be wiped between the finger and thumb with a bit of fine old
linen rag, while they are held by the edge with the other hand.
You may equally well use other glasses after they have been sub-
jected to the following treatment.

The glasses are first placed in a lo per cent, solution of car-
bonate of soda, in which they are agitated for some seconds in
such a way as to bring all the surface into contact with the liquid.
This liqliid is poured off and twice replaced with distilled water ;

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. s

266

TECHNOLOGY OF DIATOMS.

N\S

after the second time, a little sulphuric acid is added, which neu-
tralises the soda that remains and completely cleans the glasses.
The least trace of acid is then removed by very pure distilled
water, and the glasses are allowed to dry spontaneously, screened
from dust ; or, better still, they can be dried near a stove. There
then remains nothing but to wipe them before using.

The glasses, being wiped, are placed at some dis-
tance from each other on a plate of metal or very level
glass. You then take, by means of a pipette (armed
with an elastic ball), Fig. i8, a certain quantity of
liquid containing Diatoms in suspension, and these
you have well mixed up with the pipette ; then, whilst
with one hand you hold the glass lightly with a
mounted needle, you cover it with the liquid by lightly
pressing the india-rubber ball. If the quantity spread
appears too great, you can withdraw the desired quan-
tity by reducing the pressure. A little practice will
put you in the way of all the little details of this
operation.

If the glasses are as they should be, the water will

spread very evenly up to the edge. It will present a flat

surface, never in bulges. Nothing now remains but to

allow them to dry spontaneously, screened from dust,

or dried by a stove, at a temperature of 4o^C. A too-

Fig. 18. brisk dessication, or the use of too high a temperature,

generally sets up currents, which cause the Diatoms to group

themselves in little masses of a very annoying character.

Burning Diatoms on the Platinum Plate.

Certain gatherings, such as contain delicate kinds — especially
marine species, which do not admit of the use of acids during the
process of cleaning (almost all the marine gatherings are of this
class), and which have only been treated with distilled water and
the " tamisage " — ought to be at once spread on the glass and then
treated to a dull red heat on a plate of platinum, so as to destroy
the organic matters, which are found independent of the endo-
chrome in which each frustule is contained, and of which the
presence, now useless, tends to obscure the details of the siliceous
carapace.

TECHNOLOGY OF DIATOMS.

267

.V^

/.

19-

The small plate of platinum that is needful for this purpose
should be neither too thin nor too thick. If
too thin, it will present superficial irregulari-
ties, which will prevent the glasses from so
resting on it that they may be altered in shape
under the influence of the heat if it should be
a little too great ; and if too thick, it will cost
more than is needful without corresponding
advantage. That which I use measures
35 X 30 mm., and has a thickness of from
i/ioth to i^. I hold it between the jaws of
a little test-tube holder (Fig. 19), to expose it
to the flame of a small spirit-lamp.

Three or four glasses of 1 6 mm. may be
burnt at the same time on a platinum plate of
the size I have indicated. It is placed above
the flame and gradually lowered until it
assumes a dull-red tint ; you may in certain
cases carry it as far as a cherry red, but with
great care and for a very short time. In order
to judge the better of the intensity of the heat
as represented by the colour that the platinum
plate assumes, it is well to conduct the opera-
tion in a feeble light. During the operation
the surface of the glasses becomes, first,
brown, then black, and then perfectly white,
which indicates that the carbonaceous matter
is all consumed, and it only remains to fix
the glasses on the cells that have been pre-
pared for them.

The glass slip, with the cell, having been
wiped from dust, is slightly warmed over a
spirit-lamp to drive off any moisture; or,
better still, placed on a plate having a tem-
perature of about 4o''C. You place the thin
glass with the diatoms downwards on the cell,
and, holding the slip by one end, warm the other in the lamp-
flame, pressing lightly and perpendicularly on the cover-glass with

268 TECHNOLOGY OF DIATOMS.

a mounted needle. Under the influence of the heat the upper
part of the cell softens, adheres to the cover-glass, and fixes it
there in a manner absolutely hermetic. The plate, when cooled,
is put on the turn-table, with a coat of cement to protect the
edges of the cover-glass, and the preparation may be considered
as permanent, unless after a certain time the cover-glass should
crack and allow damp to enter.

Mounting in Resinous or Mixed Mediums.

This mode of mounting is that usually adopted, and, besides,
it ensures absolute permanence if the media employed have been
well prepared, and also the details of the more delicate of the
siliceous carapaces of the Diatoms are most clearly shown, espe-
cially if the medium employed is one which possesses a high
refractive index.

The Diatoms are spread on the cover-glasses in the way I have
previously indicated. If the gathering or the deposit contains the
larger species, it will be well to separate these from the smaller
and to make separate preparations ; that is to say, the result of the
washing of this gathering should be divided into a heavier and a
lighter part. This division, as I have explained in the chapter on
" Cleaning," can be effected by repeated decantations, or, better
still and in a more regular manner, by the employment of tamis-
filters.

If the materials are the result of washings made with acids,
and have been freed from all organic matter, the burning on the
platinum plate becomes unnecessary. Only those special kinds
which I have already mentioned require this operation. These
materials, and also the lighter deposits, can be mounted directly
in the balsam without it being necessary to fix the valves on the
cover-glasses. It is not the same with the heavier kinds, for then
a cover-glass carefully spread with Diatoms of large size becomes
unsightly (affreuse), when heat is applied for hardening the resin,
which developes bubbles of vapour that crowd the valves one on
the other, causing;; them to unite in groups, and often driving them
to the edge of the cover.

This fixation is obtained by placing the Diatoms that it is
desired to spread and fix in water containing a very small quantity

TECHNOLOGY OF DIATOMS. 269

of gum. This is how this water is prepared so as to have it
always ready. You choose some bits of Gum Arabic, extra white,
which are first washed and then dissolved in very pure distilled
water. This solution, which should be very fluid, is then filtered
twice through a double filter. You add to loo grammes of equally
pure distilled water some drops of the solution of gum. It is
needful that the quantity of gum so added shall be enough to fix
the Diatoms, and yet so thin that when dried it shall leave no
trace on the glass — that is to say, that the film deposited shall be
so thin as to be invisible.

The covers, thus prepared and well dried, are ready to be
placed on the balsam.

Cafiada Balsam. — A certain number of resinous media have
been, and still are, used for mounting Diatoms. First of all,
Venice turpentine was used, and then Canada balsam, which is
not really balsam, but simply a resin obtained from the Abies
Canadensis. As it can be obtained very pure and very limpid, it
is the medium most generally used in micrography.

The best preparation of Canada balsam for general use is
obtained by allowing the balsam to thicken till it comes to the
consistence of a very thick mass. You then add enough benzole
to form it into a semi-fluid liquid.

You place a drop of this balsam on the slip of glass, and then,
after having, by means of a pipette, applied a drop of benzole to
the Diatoms on the cover-glass, and quickly placed the latter on
the drop of balsam, causing it to be begin contact with the slip on
the left, and lowering it gently towards the right, using a mounted
needle. By this means you avoid the enclosure of air-bubbles,
which, though they may be got rid of by employing heat, are
nevertheless useless and troublesome. You then warm the slide
on a hot plate, or above a spirit-lamp, to expel the benzole and
harden the resin. The preparation, when cooled, is then washed
and cleaned with benzine ; then the cover-glass is sealed down
with a coat of cement of black lac, so as to guarantee the prepara-
tion from all external agents. As Canada balsam has only a feeble
index of refraction (i"52), it has long since been replaced, espe-
cially for the mounting of Diatoms, by Styrax and other similar
balsams.

270 TECHNOLOGY OF DIATOMS.

Slyrax. — We have here a true balsam of a composition very
complex, obtained from the Styrax orientalis. This balsam, of a
deep brown colour, contains cinnamic acid, a near neighbour to
benzoic acid, as well as numerous impurities, from which it must
be freed. This is the method that I employ, and which is mainly
that described by M. le Professor J. Brun for the preparation of
Tolu.

The balsam of commerce is boiled with enough water (about
twenty times the volume of the balsam under treatment), renewed
twice ; the floating mass, very soft after it is cooled, is then
exposed in saucers and placed on a stove till it becomes brittle.

The mass is then dissolved in benzole, then filtered twice in a
funnel, of which the upper part is covered with a plate of glass.
The filtered portion is exposed, protected from dust, until by the
evaporation of the benzole it acquires the desired consistence — a
semi-fluid. The index of refraction of styrax is i"62.

Balsam of Tolu, Liqtdd Amber. — It was M. le Professor J.
Brun, of Geneva, who first proposed to employ balsam of Tolu to
replace Styrax. Balsam of Tolu is obtained by making incisions
in the bark of the Toluifera balsamum. Tolu is less dark than
Styrax and is prepared in the same manner. In commerce you
can meet with Tolu that has been deprived of the benzoic acid by
washing with water. In this case, it is only necessary to dry the
mass on a stove without further washing. The index of refraction
of Tolu is I '64.

Liquid Amber — which is extracted from Liquidamber styraci-
flua — is found in commerce in a fluid or viscous form. The
latter is the only one for our use ; in other respects, it has a close
analogy with Tolu, without possessing any advantages.

Unless the various balsams (Canada balsam alone excepted)
are prepared with great care, and completely free from the acids
they contain, you run the risk, after a certain time, of seeing
numerous crystals form in the mass — crystals that often make the
preparation unfit for study. Their index of refraction is the reason
for employing them, but their brown colour is disagreeable, and it
is this, above all, that has always made me prefer the Monobromide
of Naphthaline mixed with Canada balsam. Diatoms are mounted
in Styrax Tolu in the same manner as in Canada balsam. -

TECHNOLOGY OF DIATOMS. 271

Nahire of Moiwbroinide of Naphthaline and Catiada Balsam. —
The Monobromide of Naphthaline is a Hquid, very fluid, of a
golden yellow when pure, very subtle, and very penetrating. Its
index of refraction is i"65. In mixture with Canada balsam it
constitutes a medium of a clear and agreeable colour, and still
possessing an index of i"62, which is equal to styrax.

The mixture is made by adding one volume of Canada balsam,
very thick and very pure, to an equal solution of Monobromide of
Naphthaline. They are agitated from time to time to cause an
intimate union of the two, which then form a semi-fluid of a very
clear yellow.

The use of this mixture for the mounting of Diatoms requires
certain observations and certain precautions :

I. — It is absolutely necessary that the vessels in which the
mixtures are made, and in which they are kept, should be kept
absolutely free from all traces of moisture, and hermetically sealed,

2. — At the moment of mounting, which is done in the same
way as with the other media, it is needful to pass the slip and cover
rapidly over the flame of a spirit lamp to drive off all moisture.

3. — The mixture cannot be hardened without losing, in great
part, its index of refraction, by the evaporation of a part of the
Monobromide. These preparations should be allowed to dry
spontaneously in the open air for some days, or for some hours in
a stove from 30 to 4o°C, after which the cover should be sealed
down with two or three coats of lac cement.

The Mysteries of Flowers. — One of the most mysterious
elements of flowers is the perfume, the essential action of which
in plant-life cannot be demonstrated by the wisest of our scientific
men. Gas can be weighed, but not scent. The smallest-known
insect that lives in the heart of the Rose can be caught by a
microscope lens and made to give up the secret of its organisa-
tion ; but what it is that the warm summer brings us Irom the
wild flowers of the hillsides or wafts to us from the choice plants
of the hothouse no man has been able to determine. So fine, so
subtle, so imponderable, it eludes weights and measures. — Journal
of Horticulture.

[ 272 ]

Britisb Ibi^bracbnib^.

By Charles D. Soar. Part V. Plate XII.

IN our last paper we considered the genus Nescea. We will now
turn our attention to Fiona, a genus very closely allied to it.
C. L. Koch, in his Deutschla^ids Crustaceans, etc., does not
mention this genus; but in his Ubersicht, 1842, he separates five
species from the genus Nescea (in which genus he had previously
described them), and places them in a new genus, which he named
Fiona. The five species so separated from the Nescea were Fiona
ovaia, F. rufa, F. viridis, F. affinis, and F. fasciata, making F.
ovata his type specimen. In 1879, Neuman put one species
{P. viridis) back again into its old place, and in his Stvedish
Hydrachnider he also gives and describes this genus, adding five
more species to the list already given— namely, Fiona fusca,
F. mira, F. flavescens, F. la.pponica, and F. abnormis ; but at the
same time he expresses a doubt as to the propriety of the classifi-
cation of all these species under one genus.

Neuman, however, appears to think that Koch had not suffi-
cient data to warrant him in creating this new genus. I here give
a translation from Neuman's work, Sivedish Hydrachnider, 1879,
p. 51, so that readers may see for themselves what he says : —

" In my account of the spiders and ' water-mites ' of Gothland
and Bland, I mentioned that I had long felt doubtful as to the
propriety of classifying the species here in question under a sepa-
rate genus, as they should perhaps more appropriately be brought
under the head of Nescea. As defined by Koch, the genus Fiona
— differing from Nescea by the unequal distribution of the so-called
* dorsal stigmata ' (or spots), and the absence of teeth on the
fourth joint of the palpus only— does not appear to have any
raison d'etre. As regards the insubstantiality or incorrectness of
making the said dorsal spots a basis of generic division, I have
already expressed my opinion. The absence of teeth on the
feelers might appear a better mark of distinction, but for the fact
that it so happens that certain species of Nescea have such small
feeler teeth as to be imperceptible except when very strongly
magnified, and that Fiona abnormis is likewise provided with

BRITISH HYDRACHNID^. 273

similar teeth. The pointed projection or prickle, directed forward,
which is set upon the point of the fourth joint, and which some-
times attains a length half as long as the fifth joint, appears, on
the other hand, peculiar to this genus. Another and more essen-
tial difference between Nescea and Fiona appears in the formation
of the ' fold of generation,' for in the case of the last named this
has about the same form as in the case of Limnesia and Hygro-
bates ; that is to say, the crevice is surrounded on either side by
three stigmata only, while the genital fissure in Nescea has numer-
ous smaller ones on each side, which are quite different in shape
to these."

It will therefore be seen that there are two very important
features in which Fiona differs from Nescea, namely, the pointed
projection or prickle on the edge of the fourth joint, which partly
overlaps the fifth joint (see PI. XII., Fig. 2, and the three genital
pores on each side of the genital crevice (Fig. 3). These two very
distinctive features, I think, are sufficient to warrant Koch in sepa-
rating the mites which bear these peculiarities from the genus in
which he had originally placed them.

In the extract given above from Neuman, the reader will
notice two more genera mentioned — namely, Limnesia and Hygro-
bates, neither of which we have at present considered ; but we
shall come to them later on, when those interested in these crea-
tures will be able to compare the drawings of the genital area one
with another, and see how near the similitude is. That Neuman
himself was satisfied with the separation of this genus from Nescea
is proved by his adding five species to the list.

Genus V. — Fiona.

1842. — Fiona, C. L. Koch, Ubersichi des Arachnidensy stems,
Heft 3, p. 13, Tab. i, Fig. 4.
Body soft. All tarsi have claws. Legs have swimming hairs.
Palpi not pincer-shaped, but on the anterior margin of the last
joint but one is a short, peg-like appendage near the fifth joint.
On each side of the genital crevice are three pores only. Eyes
wide apart. Mandibles in two distinct portions ; Epimera forming
two groups on each side.

274 BRITISH HYDIIACHNID^.

Fiona ovata (Koch).
1835-41. — Nescea ovata, C. L. Koch, Deutschlands Crust., etc.,
N.S., Fig. 13.

1842. — Fiona ovata, C. L. Koch, Ubersicht des Arachnidensy stems,
Tab. — , Fig. 4.

1879. — Fiona Jlavescens, Neuman, Sveriges Hydradmides, p. 54,
Tab. II., Fig. 4.

This I believe to be the same mite given by Koch as the type
species of Fiotia, and also Neuman's " F. Jlavescens." It is a very
beautiful Hydrachnid, of a fair size, and brilliant in colour; its
beauty cannot be seen in a black and white drawing. To be
appreciated the mite must be seen in the life. The body is 2/2 5ths
of an inch long, oval in shape, the line of the oval being slightly
depressed on either side towards the posterior margin. The
dorsal colouring is very strongly marked ; it is a bright yellow,
pale at the anterior portions, and inclined to red at the broadest
part on the margin ; in the centre is a yellow cross, cadmium in
colour, which is spotted with a darker tone. This cross is sur-
rounded with a dark patch very nearly black, and which in some
specimens looks quite so. The eyes are a deep red. The ventral
side is a little deeper in colour round the margin, but is almost
colourless in the centre. The black marking which is so promi-
nent on the dorsal side also shows well on the ventral (see Fig. 5).
At the posterior end of the genital area is an angular patch of
bright yellow, spotted with a deeper yellow, in the centre of which
is the anal plate. The legs, palpi, and epimera are grey blue, all
of which have a finely granulated surface. The first leg is about
i3/3ooths of an inch long, the second i/2oth, the third 4/75th,
and the fourth i/i5th. The palpi (Fig. 2) shows the prickle
which is one of the characteristics of this genus ; it is about
4/i5oths of an inch long. The ventral side in some speci-
mens is so covered with fine downy hairs that it is almost
impossible to make out the genital area. I have taken a
number of females of this species, but have never yet succeeded
in finding a male. The specimen from which this drawing was
made was taken from a pond at Bagshot, Surrey, Sept. 24, 1894.
I have had several species of Fiona deposit their ova on the side

f] n Journal of Micro'scopy 3^" Ser. Vol 6 Plate 12. fl ji

="-s yZ-

Wv

'*Jiy

r ,..#

r^i \l '11/ 7l-4 ^

..,;.. r \! i.i. ;■. ■•! / -71,

m'".

9

*rT * •

^1/ if i Fiona- ovatco a.?^id PiJr?^a afl^riLis

I '' ; Chas.D So3.r,ad nah del.

BRITISH HYDRACHNIDyE. 275

of the glass tanks in which I keep them in the same manner as I
described in Nescea.

Not having a male of this species, I have drawn the ventral side
of Pmia affinis $ (Koch), Fig. 6, thinking it would be interesting
to show the difference in the structure of the epimeral plates in the
male and the female ; it will be noticed that the two posterior pair
are very large, and nearly touch in the centre. This Hydrachnid
is not so large or so beautiful as P. ovata ; it is quite an ellipse in
shape, pale blue in front, and gradually turning to yellow ; the
posterior margin is quite yellow; it has a yellow cross on the back
surrounded with dark brown markings. Both male and female
are the same colour.

In Fig. 7 I give a drawing of the nymph stage of Fiona affinis,
and which, from the position of the epimera, I take to be the
nymph stage of a female. How long it remains in this stage I
cannot say. 1 have kept it eight months in a tube and it still
looks in good condition, it has plenty of colour (it is the same
colour as the adults), and swims about vigorously. I have exam-
ined it at intervals, but can see no change whatever ; in this stage
there are only two genitals on each side in a special plate. The
nymph of Fiona can easily be recognised from the nymph of
Nescea by the last pair of epimeras being extended backwards
to a point.

EXPLANATION OF PLATE XIL

Fig. 1. — Dorsal view of Fiona ovata, ^ •

2. —Palpus of same, showing the peg on the fourth joint.

3. — Genital area of same, showing the position of genital suckers.

4.— Mandible.

5. — Ventral view of same.

6. — Ventral view of Fiona affinis, ^ ,

7. — Ventral view of Fiona affinis, nymph.

8. — First leg of Fiona ovata, ^ .

9. — Fourth leg of ditto.

[ 276 ]

Comparative Bnatom^. ''

THE two handsome volumes before us form a complete and
very valuable Text-book of the Comparative Anatomy of
the Invertebrata, in compiling which the author has endea-
voured to do full justice to the numerous important results of the
research of the last decades. They contain, separated as far as
possible from the portions devoted to the main subject, the ele-
ments of Comparative Embryology, which will undoubtedly be
welcome to many students. The Comparative Anatomy of the
different animal races has been prefaced by short systematic
reviews, which will prove useful to the student or systematic zoo-
logist. The medical student will also find much valuable zoologi-
cal information.

Vol. I. commences with a short introductory chapter on The
Cell, followed by a Systematic Review of the PROTOZOA.
Chapter II. treats of the METAZOA, and gives systematic reviews
of the ZooPHYTA or Ccelenterata — Class i, the Gastr^adte;
Class 2, PoRiFERA, or Sponges ; and Class 3, Cnidaria. Chapter
III., PLATODES. Chapter IV., VERMES. Chapter V.,
ARTHROPODA-ARTICULATA— First Division, Crustacea;
Second Division, Tracheata ; Class i, Protracheata ; Class 2,
Antennata ; Class III., Arachnoidea or Chelicerota and
Tardigrada.

Vol. II. treats of the MOLLUSCA, ECHINODERMATA,
and ENTEROPNEUSTA.

With a view to giving our readers a better idea of the very
thorough manner in which the various subjects in these books are
treated, we shall, with the publishers' permission, make a few
extracts, and illustrate them with sortie of the blocks which they
have kindly placed at our disposal. We turn, therefore, to Chap.

* " Text-Book of Comparative Anatomy." By Dr. Arnold Lang, Professor
of Zoology in the University of Zurich, formerly Ritter Professor of Phylogeny
in the University of Jena. With Preface to the English Translation by Prof.
Dr. Ernst Haeckel, F.R.S., Director of the Zoological Institute of Jena.
Translated into English by Henry M. Bernard, M.A.Cantab., and Matilda
Bernard. Parts I. and II., 8vo. Part I., pp. xviii. — 562 ; Part II., pp. xvi. —
618. (London: Macmillan and Co. 1891 and 1896.) Price 17/- each net.

COMPARATIVE ANATOMY. 277

II., which describes the Metazoa. Here, we are told, in contra-
distinction to Protista or Protozoa^ we have real Animals or Aleta-
zoa. " The bodies of the former consist of one single cell or of
several similar cells (with the exception of Vo/vox), each of which,
however, is competent to perform all vital functions (cell colony) ;
the bodies of Metazoa, on the contrary, always consist of a num-
ber of cells, which are not all similar, but have divided among
them the different forms of vital activity (cell community). The
division of labour may be more or less complete, and according to
it the degree of morphological complexity and of physiological
perfection is determined. There are animals which are morpho-
logically (according to structure) and physiologically (according to
their vital activities) only a little raised above the Protozoan
colony — e.g., the Hydra.

" The bodies of these animals consist of only slightly different
sorts of cells : digesting cells, neuro-muscular cells, stinging cells,
and formative cells of eggs and spermatozoa. All these kinds of
cells are, however, indispensable to the existence of the Hydra
body ; not one of them can be removed from the body without
endangering its existence. The whole body is nevertheless physi-
ologically an individual, but, as opposed to the cell, an i?idividual
of a second ; i.e., a higher order — a person. Most animals remain
at this stage of individuality. A Medusa, a Worm, a Crustacean,
or a Mammal, is such an individual of the second order. In many
animal divisions, however, the individuals of the second order
multiply by fission or gemmation. The new individuals thus aris-
ing remain united, and together form i?idividuals of the third order
— an animal stock. The single individuals which collectively form
such a stock may remain similar, and they may then be related to
the stock in just the same way as the cell-individuals of a Proto-
zoan colony are related to the colony ; or division of labour again
sets in, resulting in variety of development in body, form, and
structure of the person forming the stock (polymorphism). Then
such r< stock is physiologically again an individual of the third
order. The single persons become equivalent to instruments of
this complex individual, and bear the same relation to it as the
various cell elements of a single individual — e.g., a Hydra — bear
to it. As instances of animal stocks without division of labour

278 COMPARATIVE ANATOMY.

among the persons, we have most Corals; and of stocks with far-
reaching division of labour and polymorphism, the Siphonospora.

" Even in the lowest Metazoa the cell elements are not found
scattered in the body without any special arrangement. On the
contrary, we find even among the simplest Ccelenterata that they
are arranged in two epithelium-like layers, which are closely con-
tiguous and form the wall of the body, which is pouch-shaped and
provided with an opening. In keeping with the physiological
activities of the various cells, the stinging cells and the neuro-
muscular cells form the outer layer, while the digesting cells form
the inner layer, which is turned towards the pouch cavity — i.e., the
gastric cavity. The reproductive cells lie protected in the deeper
portions of the outer layer. These two layers, which occur in the
development of all Metazoa, are called the Ectoderm and the
Endoderm."

Turning to Class III. — Cnidaria, sub-class Hydrozoa — we
read: — " In all Hydrozoa an ectodermal cesophagus is wanting.
The mouth leads direct into the endodermal gastric cavity.
Gastral filaments are wanting. The sexual products mostly arise
from the ectoderm. The sexes are generally separate."

Asexual reproduction is very common among the Cnidaria,
side by side with sexual reproduction. Among the Cteitophora
alone it has not been observed. In Hydra we find asexual repro-
duction by gemmation side by side with sexual reproduction in
adult animals. Buds are formed by hollow outgrowths of the
body-wall. These buds grow, and at the distal end a breach is
formed — an oral aperture, round which the tentacles arise by
means of the new outgrowths. Such buds can detach themselves
from the mother-body, or they may in small numbers remain
united with it for some time. In the last case small Hydra colo-
nies, composed of similar individuals, arise.

In the same way, elegant and richly-branched colonies arise in
most Hydroids (Fig. 20). The individuals of such stocks are,
however, generally not similar, but, as a consequence of more or
less division of labour, Dimorphism or Polymorphism takes place.
We distinguish (i) sterile ?iutritive persons, which remain on the
level of the Hydroid, and undertake the feeding of the stock, the
gastric cavities of the individuals of the stock being in communi-

COMPARATIVE ANATOMY.

279

cation with one another ; (2) Sexual persons, which undertake the
duty of ripening the sexual products and also of planting them
out and dispersing them, so that the young brood of Hydroids
proceeding from the fertilised egg may attach themselves in new
places and form new stocks. l"he sexual persons which are des-
tined for a free-swimming life, and which are buds of the Hydroid
stock, attain a structure corresponding with this manner of life ;
they become young Craspedote Mcdusce, which detach themselves
from the stock, swim away, and — often after longer or shorter
metamorphosis — ripen the sexual products.

Fii^. 20. — Bougainville ramosa (after Allman), with budding Medusse.
h. Nutritive polyps; vi.k.. Medusa buds; w., Detached young Medusa

{Margalis ramosa).

Turning now towards the end of Vol. I., we come to Class
Afitennata, sub-class Hexapoda or Insecta, which is thus described :

"The body of the Hexapoda falls typically into three parts, quite
distinct from each other : head, thorax, and hind body (abdomen).
The unsegmented head probably originally consisted of four seg-

280

COMPARATIVE ANATOMY.

ments. The thorax is composed of three segments : prothorax,
mesothorax, and metathorax, answering to the three anterior trunk
segments of the Myriapoda. The typical number of segments in
the hind-body is ten or eleven. The thorax and the abdomen
together form the trunk, which may be compared with the trunk
of the Symphyla. Among the Apterygota the Thysaiiura possess
ten abdominal segments, and the CoUembola a varying number, but
always less than ten. In the Pterygota the number of abdominal
segments in the adult animals varies, and is generally less than ten.
This diminution is caused by the fusing of those segments which
are connected with the genital apparatus and lie in front of the

Fig. 21, A — D.
The Nervous Systems of Four Species of Diptera,
to demonstrate their various degrees of concentration.
A, Non-concentrated nervous system of CJiirononms plumosus, with three
thoracic and six abdominal ganglionic masses. ^i5, Nervous system of Einpis
sterco7-ea, with two thoracic and five abdominal ganglionic masses. — C, Nervous
system of Tabanus bovinus, with one thoracic ganglionic mass, and the abdo-
minal ganglia moved towards each other. — D, Nervous system ot Sarcophaga
carnaria. All the ganglia of the ventral chord except the infra-oesophageal
ganglion, which always remains separate, are here united into one single
thoracic ganglion mass. — (After E. Brand.)

COMPARATIVE ANATOMY. 281

last ; and, secondly, by the fusing of the anterior abdominal seg-
ments (usually only the first) with the thorax. On the other hand,
in a few insects {Macrolcpidoptera, Diptera, and Rhyfuhota), the
last (third) thoracic segment is joined with the abdomen.

"The nervous system of the winged Insecta shows very great
variety in its arrangement ; the Diptera (Fig. 21, A — D) are par-
ticularly instructive. In no other order of insects are the extremes
so great, and yet connected by such numerous intermediate stages.
The series begins with the sub-order of the CuHcida;, Culiciformes,
TlpulidcB, Fimgicohe (e.g., Chironomus, A), which have very slightly
concentrated nervous systems. The ventral chord here consists of
an infra-oesophageal ganglion, three thoracic ganglia, and five to
six abdominal ganglia. The last thoracic ganglion is not simple,
but at least one of the anterior abdominal ganglia is fused with it.
The last and largest abdom.inal ganglion is also not simple ; it
consists of several (in Chironomus probably two) fused ganglia.
The concentration of the nervous system among the Diptera
begins in the families of the Empidce, Asilidce, TherecidcB, Xylo-
phugidcB. Bibionidce. {e.g., Empis, B.), where the two anterior tho-
racic ganglia become fused, so that there are only two thoracic
ganglia. In this respect the Diptera forms a contrast to other
insects with only two thoracic ganglia — e.g., many Coleoptera,
Lepidoptera, and Hymenoptera. In these cases it is the posterior
thoracic ganglion which consists of the two fused posterior ganglia.
Tabamcs (Fig. C) exhibits a nervous system, in which all the three
thoracic ganglia are fused into one thoracic ganglion mass. This
is the case in the families of the Syrphidce, Stratiomida, and
Tabanidce. The abdominal ganglia show a tendency to approach
each other and to fuse. Finally, the highest degree of concentra-
tion among the Diptera is shown in the Muscidce, CEstridce,, and
Pupiparce, where all the ganglia of the ventral chord, except the
infra-oesophageal ganglion, are fused into one large ganglionic mass
(Fig. 21, D, Sarcophaga). From this nerve a median nerve runs
towards the end of the abdomen, giving off nerves to the abdo-
minal segments at regular intervals.

Turning now to the Second Volume, we come to a most inter-
esting chapter on the Ontogeny of Chiton /'<9///(Mollusca), Fig. 22.
The egg possesses little nutritive yolk. The segmentation is total

International Journal of Microscopy and Natural Science.

Third Series. Vol. VI. t

Fig. 22. — Development of Chiton Polii (see p. 283).

COMPARATIVE ANATOMY. 283

Fig. 22. — Devklopment of Chiton Polii (after Kowalevsky).
A — F, Six stages in the development of the gastrula into the young Chiton,
sections nearly median. — G, Frontal section through stage C, oblique, from the
upper part of the velum to the blastopore. — H, I, K, L, Transverse sections of
four stages of development behind the mouth, i, Blastopore ; 2, Archenteron
or mid-gut ; 3, mesoderm ; 4, octoderm ; 5, velum or preoral ciliated ring ;
6, stomod.-eum or oesophagus ; 7, mouth ; 8, radular sac ; 9, body cavity ;
10, pedal gland, in one oesophagus; 11, foot; 12, anus with proctodseum ;
13, cerebral ganglion ; 14, pretrochal tuft ; 15, pleurovisceral cords; 16, pedal
cords; 17, mantle furrow; 18, eye; c, shell; c\ — cj, the seven shell-plates,
first formed.

and somewhat unequal ; a coelogastrula is formed by invagination.
a, The blastopore of the gastrula larva marks its posterior end.
A pair of endoform cells near the dorsal end of the blastopore are
specially large. A longitudinal section shows two dorsal and two
ventral ectodermal cells, with larger nuclei ; these belong to a
double row of cells, on which is developed the preoral ciliated ring,
which, in Molluscs, is called the velum (Fig. 22, A).

(b) At a later stage, the blastopore appears shifted somewhat
towards the ventral side, and an inward growth of ectodermal cells
begins at its edge ; this is the commencement of the formation of
the ectodermal stomodceum. At the posterior and upper edge of
the blastopore there is, in the figure, a cell lying between the
endoderm and the ectoderm ; this is, no doubt, a mesodermal
cell (B)

(c) The larva elongates ; a distinct stomodasum (embryonic
oesophagus), leading through the blastopore into the archenteron,
is formed by the continuous growth inward of the ectodermal
cells. This organ becomes shifted still further forward along the
ventral surface (C).

(dj Fig. 22, {?, is an oblique section from the anterior upper to
the posterior lower point through a slightly older larva, which
shows the stomodgeum, and, at the sides of the blastopore, the
^rsl mesoderm cells. These are probably derived from the endo-
derm, and are symmetrically placed at the two sides of the blas-
topore.

(e) A median section through the next stage (Z>) shows no
mesoderm cells as yet in a median place. The mouth, however,
appears shifted forward along the ventral side as far as the ciliated

284 COMPARATIVE ANATOMY.

ring or velum, the double row of cells in the latter being very clear.

(f) Transverse section of an older stage (H). The mesoderm
cells have increased in number, and are arranged in two groups at
the sides of the stomodsum, between the ectoderm and the
endoderm.

(g) At a later stage — a longitudinal section of which is given in
Fig. 2 2, E — the principal feature is a stronger development of the
mesoderm, in which a space, the body-cavity, now appears. A
bulging backward of the stomodaeum forms the first rudiment of
the radular sac. Behind the mouth, a sac-like depression is
formed, evidently by the ectoderm ; this has been called the pedal
gland, although it has not as yet been discovered what becomes of
it in the adult animal.

(h) When the body-cavity forms, the cells of the mesoderm
become divided into two layers, the inner visceral layer becoming
appended to the intestine, and the outer parietal layer to the ecto-
derm {cf. Fig. 2 2, /). In the transverse section, we see, deep
down in the ectoderm, the first rudiments of the pleurovisceral
cords. The pedal cords arise in the same way, and anteriorly, in
the cephalic area, which is encircled by the preoral ciliated ring,
the rudiments of the supra-a;sophageal central nervous system form
a neural plate — i.e., as a thickening of the ectoderm, which carries
a tuft of long cilia.

(i) At later stages (F.K.L.) the central nervous system, with
the pleurovisceral and pedal cords, become detached from the
ectoderm and take up their mesodermal position. The rudiments
of seven shell-plates appear on the back as cuticular formations ;
the eighth only appears later. A posterior invagination of the
ectoderm represents the rudiments of the proctodeum (the embry-
onic hind-gut, with the anus). The first teeth appear in the
radular sac. The whole of the cephalic area and the region of the
foot become covered with cilia. On the dorsal ectoderm, on the
parts that are not covered by the shell-plates, the first calcareous
spines appear. In the posterior part of the body; a great accumu-
lation of mesodermal elements evidently marks the position of a
formative mesodermal zone.

At this stage, the larva leaves the egg envelope and swims
about freely, and, on the degeneration of the ciliated ring, sinks to

COMPARATIVE ANATOMY.

285

the bottom transformed into a young CJiihm. During the last
transformation, two lateral eyes appear on the anterior ventral side
of the body. The development of the circulatory system, the
nephridia, the genital organs, and the ctenidia has not been fol-
lowed.

Fig. 23. — Diagram of the Organisation of a Pentremites (original).

We fear our extracts have already been too lengthy. We can-
not, however, resist the pleasure of presenting our readers with
Fig. 23, which shows the Ambulacral Skeleton of the Echinodermata.

286 COMPARATIVE ANATOMY.

Description of Fig. 23.

^, B, C, D, E, the five ambulacra. A, Ambulacrum with covering-
plates (i) and extended pinnule (2). B, Ambulacrum with depressed pinnulte.
C, Ambulacrum after removal of the pinnulae and covering-plates. D, After
the further removal of the side-plates and accessory side-plates (except three).
E, After removal of the lancet plates as well. In the centre is seen the mouth
with the spiracles surrounding it; in the posterior inter-radius the anus, i,
Covering-plates ; 2, pinnulse ; 3, deltoid plates ; 4, their sloping ambulacra!
edges ; 5, side-plates ; 6, lancet plate ; 7, pores ; 8, outer or accessory side
pieces ; 9, furrow of unknown significance on each side-plate ; 10, radials
(fork-plates); 11, aperture of the ambulacral canal; 12, lower lancet plate;
13, hydrospire folds.

We have been deeply interested in the perusal of these books.
The ilkistrations, upwards of 850 in number, are all good, and the
explanatory text clear and concise. Our best thanks are due to
Messrs. Macraillan for the use of the electros and for permission
to make the above extracts.

Arrow-Poisons. — R. Hitchcock refers to the arrow-poisons of
the Ainos in a paper contributed to the report of the U.S. National
Museum. According to Dr. B. Schreube, the young side-roots of
Aconitum Japonicum are gathered in summer and dried in the
shade until autumn. Such roots as contain active poison become
softer, a process of fermentation appearing to take place, and after
removal of their outer coating are rubbed to a pasty mass between
two stones. The material is then ready to be spread upon the
arrow-heads, or may be preserved, without the poison losing its
activity, for five months. The results of chemical and physiolo-
gical investigations of the poison by Dr. Stuart Eldridge, whilst
confirming the supposition that aconite is the active ingredient,
seem to indicate that other, probably inert, substances are also
present in the compound. This observer states that the mass,
after being mixed, is buried in the ground^ and on its removal
appears as a stiff", dark, reddish brown paste, which, before appli-
cation to the arrows, is mixed with a certain proportion of animal
fat. — Nature^ xlvi., 475.

[ 287 ]

Significant IDeetioee in Jfamiliar iflowers.

By E. M. Hardinge, Glendale, U.S.A.

IN the very centre of the wild carrot, at the hub of its wheel of
bloom, is one small, vivid crimson or purple spot. On
examination, this bit of brightness proves to be a dwarfed
and distorted cluster of sterile blossoms.

We get a light upon its meaning when we see, in a tropical
member of the Parsley family, a little disc of red purple flowers in
the heart of the large disc of white ones. In our wild carrot the
rosy or purple blossoms of the central cluster set no seed, shed no
pollen, and are scarcely conspicuous enough to lure insects to the
fertile white blossoms which surround them. They are often so
distorted and so crowded together, that the colour-spot has no
symmetry, and we can scarcely believe that it has been, or could
be, a disc of delicate flowers like those at the outer circumference
of the wheel of bloom. Is this colour-spot a new departure or a
reminiscence ? The last supposition is quite as likely as the first,
for Nature's changes are often eliminations.

Many common wild flowers are even now in process of change,
and in them the botanist finds organs that are dwindling, or traces
of organs that have almost entirely dwindled away. Thus, the
members of the great Crowfoot family — the Ratmnculacecz — show
a strong inclination to rid themselves of petals. Aconite, Colum-
bine, and Larkspur represent the initial steps in the process. In
these flowers the petals are present, but the sepals are so large and
brightly coloured as to be quite sufficient lure to insect visitors.
Indeed, bright and conspicuous sepals are borne by many members
of the Crowfoot tribe.

The petals of such flowers are no longer necessary as insect
lures. They are, in fact, " thrown out of a job," and Nature, it
seems, offers them their choice of two alternatives : either they
must assume some new task in the floral division of labour, or
they are doomed to dwindle, in obedience to a general law of all
unused organs. The petals of the Columbine are assisted in the
advertising business by the sepals, which rival them in richness or
delicacy of tint, so they have taken up other duties in the floral

288 SIGNIFICANT VESTIGES IN

economy, and have resolved themselves into honey-bearing spurs.
This modification of the outrivalled petals is found in several
members of the Crowfoot tribe. The Marsh Marigold {Caltha
palustris) has large yellow sepals, which simulate petals and act as
such, the true petals meantime being present as honey-bearing
horns. In the Hellebore, also, the petals have been converted
into nectaries.

The calyx of the Larkspur is so vivid in colour that the petals
are not now essential to make the blossom attractive to insects.
Nature, therefore, has assigned them additional duties, and only
by performance of these do the petals keep their place. The two
upper ones are converted into horns of plenty, stored with nectar,
and the two lower are so shaped and placed as to cover the
stamens and protect the pollen from thieving crawlers and rain.

In the most highly-specialised member of the family, the Field
Larkspur ( Delphmum cofisolida), these four petals have united
into one body. " The stamens," says Sir John Lubbock, " mature
one after the other, and each, as it ripens, raises its head into the
small entrance to the flower, so that the proboscis of the bee, in
pushing down to the nectar, can scarcely fail to jostle the anther.
After shedding their pollen the stamens retire, and the stigma then
comes up and occupies the place they have vacated." Flowers
with their honey at the bottom of a deep spur are said by Miiller
to have lost the power of self-fertilisation, and the Larkspur,
according to Sir John Lubbock, is utterly unable to set its seed
without the visits of the humble bee.

Following the rule and custom of the Crowfoots, the four-
petalled Larkspur should have a fifth petal, and it is probable that
the flower once possessed one. Superseded in its decorative duties
by the brilliant calyx, and finding no other work to do, this petal
became useless and atrophied. It has left no trace behind, but
we surmise its story from the fate which has overtaken similarly
circumstanced petals in the Larkspur's next-of-kin, the Aconite.

In Aconite the process of atrophy has gone still farther. The
calyx has assumed all the duties of a corolla, and the petals are
reduced to two. The other three are sometimes visible as very
minute rudiments among the stamens — mere reminiscences of
bygone glories — and are sometimes altogether wanting. When the

FAMILIAR FLOWERS. 289

calyx is corolla-like, and the superseded petals do not assume
other duties, they dwindle and disappear.

In Myosuriis they are linear ; in Isopyrum they have become
minute ; and in Zanthorhiza they are tiny glands, not much bigger
than commas. Bright and delicate sepals are the sole and sufifi-
cient adornment of the Hepatica, Trautvettaria, Anemone, Cle-
matis, and Hydrastis. No petals at all are present in these
flowers, even as rudiments. In Cimicifiiga and Hydrastis the
delicate and decorative sepals fall off almost immediately after the
flower has expanded, showing that the last stage in this series —
that of dispensing altogether with floral envelopes — is nearly
reached.

It is still more nearly reached by the Rue ( Thaiictriun), which
has no petals, and merely the rudiments of sepals. The Thalic-
tru?n produces no honey, but without stored sweets or floral enve-
lopes it bids for and secures the attention of insects. They are
lured by the conspicuous stamens, which are made to do the duty
of the absent petals as well as their own.

■ Cimicifuga, or Bugbane, attracts insect visitors by a like device,
for after its inconstant and fugitive sepals are gone, its great fea-
thery spine of cream-white stamens is very noticeable amid the
green shadows of its woodland haunts.

Atrophy of the fifth stamen is found in flowers of two orders :
the Figwort family and the Bignonia family. In Chelone the
stamen in question is present, but smaller than the others, and
generally sterile — a step towards atrophy. In Collinsia it is a
slender rudiment, and in Scrophiilaria it has dwindled to a mere
scale ; " a thing," says Prof. Gray, " of no use whatever to the
plant, but very interesting to the botanist, since it completes the
symmetry of the blossom."

In Gratiola and Hysanthes, the fifth stamen has, it seems,
entirely disappeared and two more are being eliminated — are
present, but sterile. Veronica has reached the goal with two
stamens and no rudiments, and it gives further proof of its high
organisation in its bright blue colour, in the shape of its corolla,
and in the distinct drawing of its honey guides. Its poorest rela-
tions are the common mullins. Their colours, yellow and white,
are, says Grant Allen, worn by " the earliest and simplest types of

290 SIGNIFICANT VESTIGES IN

existing flowers." Their flat, symmetrical, open corollas prove
them to be but little specialisedj and they still bear the fifth
stamens which their more advanced cousins have discarded.

Most of the members of the Bignonia family are tropical, and
those which are habitues of this soil have somewhat the air of
strayed exotics. The Bignonia carreolata festoons the trees which
fringe our southern rivers, hanging its great showy orange and
crimson flowers from the topmost boughs ; and more familiar
members of the family are the Catalpa tree and the Trumpet
Creeper of our gardens. The Bignonia and the Trumpet Creeper
have each four stamens, with a very evident rudiment of a fifth.
In the Catalpa the process of elimination has gone still further,
and the flower bears but two perfect stamens, and two or three
little white threads, which are reminiscences of the rest. All these
flowers which possess stamens growing small by degrees and beau-
tifully less are monopetalous and most of them are deep-throated.
In such flowers the pollen is thriftily preserved to meet the needs
of fertilisation. The stamens are, in most cases, partially pro-
tected from wind and rain, and the pollen is therefore less likely
to be blown or washed away. Moreover, the monopetalous flower
is comparatively safe from insect robbers. In a polypetalous
flower, which keeps open house, as it were, to all comers, a crawl-
ing insect can slip in between the petals, rob the nectaries, " eat
the pollen," says Grant Allen, " to his heart's content," and go out
the same way he came in, dusted with pollen which probably will
never be carried where it should go — to another flower of the
same species. The tubular blossom is more difficult to enter and
less likely to be robbed, and, in many cases, it bids for the atten-
tion of a select circle of visitors by keeping its nectar out of the
reach of the vulgar mob, and accessible only to larger-winged
insects. Polypetalous flowers, especially those with shallow cups,
must produce enough pollen to meet Nature's requirements after
many mischances have been endured, and must hence be liberally
supplied with stamens. But with the union of the petals fewer
stamens are needed to supply Nature's needs, and the more the
blossom is tubed, the more closely, as a rule, are its anthers brought
together, and the more accurately are they pressed against the
body of any visiting insects.

FAMILIAR FLOWERS. 291

With the tubing of the blossom, Nature shows a tendency to
turn it to one side, thus preventing rain and dew from entering the
flower-cup and washing the pollen away. Hence, as the petals
unite and as the flower-cup deepens, there is a tendency for some
of the stamens to atrophy, unless they can be so changed as to
become serviceable to the flower in another capacity. This seems
to have been the alternative chosen in the case of the fifth stamen
of the Pcntste^non, or Beard Tongue. This fifth stamen has evi-
dently no present intention of effacing itself. Instead of shrinking,
it seems to have grown, for it is the largest and sturdiest stamen of
the group. It bears no anther, and, of course, produces no pollen,
but it has evidently taken up fresh work equally useful. The two
pairs of stamens are curved, so as to bring their anthers close
together just under the blossom's arching upper lip, where they
can scarcely fail to deposit a load of pollen upon the back of any
visiting insect. But the odd one stands quite apart from the rest,
and raises its head into the orifice of the corolla, just above the
blossom's lower lip. This fifth stamen is clothed, especially at its
tip, with fine silky hair, and it stands directly in the pathway to
the nectar.

A thicket of fuzz growing on the corolla and along the pathway
to the nectar is a device which has been adopted by several flowers
of widely differing species. Among the orchids, Calopogon and
Arethtisa are bearded along the upper surface of the lower lip.
Chelone and Antirrhinum, both members of the Fig wort family,
are bearded in the throat, and in many violets a velvety tuft grows
just above the entrance to the spur, in which the honey is found.
In every one of these flowers — -as Sir John Lubbock has shown —
the fuzz is there to prevent ants and other small pedestrians from
crawling down after the honey, which the flower is trying to save
for some winged insect friend. Flying insects with long probos-
cides make no difficulty of the vegetable fur, but it is a formidable
obstacle to crawlers.

A few long scattered hairs clothe the lower lip of the Pent-
siemoji, and act as additional guardians to the flower's stored
sweets. But the brunt of the work of defence has been assumed
by the bearded fifth stamen. It opposes a formidable obstacle to
crawling thieves, and may also serve to bring the back and shoul-

292 SIGNIFICANT VESTIGES IN

ders of flying insects more closely into contact with the anthers.

By thus making itself useful, the fifth stamen of the Pentstemon
keeps its place and its importance, while the corresponding organ
in almost every other member of the Figwort family is dwindling,
or aborted, or has utterly vanished away.

The Indian Turnip, or " Jack in the Pulpit " ( Ariscema tri-
phyllum) is in a state of transition and has nearly become a dioe-
cious flower. Prof Gray calls it " by abortion dioecious." The
green spathe encloses a glossy spike, around the base of which will
be found a group of pistils or a group of stamens. But one Jack
in a baker's dozen is a case of atavism, it seems — a reminiscence,
perhaps, of some bygone time when all Jacks bore both stamens
and pistils. The base of its spadix is surrounded by a group of
pistils, with two or three stamens above them, or by a group of
stamens, with two or three pistils below them. This arrangement,
occasionally referred to, as it were, by the Indian Turnip, is fre-
quently adopted by the Green Dragon ( Arisama Dracontium),
and is still habitual with the near relations of the Arismma, Pel-
tranda virginica and Calla palustris. But the majority of the
Indian Turnips are unisexual, and thus in this family we have a
distinct series, advancing, by abortion, from a lower to a higher
mode of reproduction.

The atrophy of leaves in parasites is a familiar story. Botan-
ists count ten or twelve native plants, representing four widely
different orders, which subsist, partially or entirely, on vegetable
juices sucked from other plants.

The Eye-bright (Euphrasia) and the Yellow-rattle (Rhinanthus)
are just entering upon a similar mode of life, following the evil
example of their first cousin, the Painted Cup ( Castillea), which
is a thorough-going root parasite. Eye-bright and Yellow-rattle
are known to eke out their rations, now and then, with juices
, drawn from the roots of whatever grows nearest, and it is not
improbable that there are other plants, as yet untouched by suspi-
cion, which feed; partially or occasionally, upon nourishment
unlawfully purloined from their neighbours. But this nefarious
practice cannot remain long unsuspected, for as soon as a plant
forms a habit of parasitism it begins to lose its healthy green
colour, and its looks betray it.

FAMILIAR FLOWERS. 293

An honest, hard-working plant, which grubs for its own living,
has in stem and leaves an abundant supply of chlorophyll. To its
presence the rich greens of vegetation are due, and by its means
animal substances, water, and gases are converted into vegetable
fibre. But the plant which takes its food, already partially
digested, from some other plant, needs less chlorophyll for its
support, and Nature, with wise thrift, bestows less chlorophyll
upon it. Then its leaves begin to dwindle and its green colour to
fade, and it is driven to more and more complete parasitism by
growing unfitness for self-support.

At one end of this chapter of vegetable crime and retribution
is the little Eye-bright of the New England hills, still bearing green
leaves, and, to all outward appearance, living as honestly as its
neighbours. At the other end is the Indian Pipe or Ghost Flower,
an out-and-out root-parasite, with all its stems faded to a corpse-
like pallor, and with its foliage dwindled away to small, scattered
whitish scales.

The atrophy of the fifth stamen among the Figworts, accom-
panied as it is with more and more perfect adaptation of the flower
to the winged insect, may be regarded as the atrophy of advance-
ment. The dwindling and bleaching of the foliage of parasites is
the atrophy of degeneration. The atrophy of advancement is
found again if we study the growth of the fruit in some familiar
trees. When a plant, in shiftless and step-motherly fashion, hands
its off-spring over to those untender nurses, luck and chance, it
follows that an enormous proportion of the offspring will die. But
as soon as care is taken of the seed's future, making its survival
probable, fewer seeds are produced. " Diminution in the number
of seeds," says Grant Allen, " invariably accompanies every
advance in specialisation, or every fresh forward step in appliances
for more certain distribution." And "when the seeds of our
fruits become atrophied," says Darwin, " the fruit itself gains ,
largely in size and quality."

Some of our most familiar trees are even now diminishing the
number of their seeds. Nature, keeping up an age-old habit,
forms a large number of germs, but the trees, having adopted a
newer habit, neglect most of these germs, and bring only a rem-
nant of them to maturity. But these comparatively few off-spring

294 SIGNIFICANT VESTIGES IN

are sent into the world better nourished, better provided for,
better equipped for the battle of life than they would have been,
had the parent tree undertaken the maintainance of a larger
number of descendants, and thus they profit by the fate of their
little brothers which perished untimely.

The Horse-Chestnut blossom has a three-celled ovary, with two
ovules in each cell ; but the ripe Horse-Chestnut bur never holds
more than three nuts, and sometimes only two, or even a solitary
one. "Yet the vestiges of the seeds which have not matured,"
says Prof. Gray, " and of the wanting cells of the pod may always
be detected in the ripe pod." The very young acorn is divided
into three compartments, and each compartment has two ovules
hanging from its summit. One might, therefore, expect the mature
acorn to be a husk enclosing six small nuts or seeds. But, in fact,
five of the cells and five of the ovules are completely obliterated
in the forming fruit, which thus becomes one-celled and one-
seeded, " and rarely," says Prof. Gray, " can any vestige be found
of the missing parts."

The pistil of the Maple blossom has two styles, two stigmas,
two ovaries, and two ovules in each ovary, but it developes into
two-winged seeds. It is not unusual for atrophy to go still further,
and for one of the winged seeds to stop growing very early in the
season, so that the fruit turns out to be an unsymmetrical affair,
with one side swelled into firmer and plumper proportions, because
nourishment has been withheld from the other.

In the Acorns and Horse-Chestnuts which come to maturity,
the baby-plant is supplied with a particularly rich and plentiful
stock of starches on which to feed while it does its first growing,
and it is protected from damp and from insect enemies by a tough,
horny shell. The maple germ is also provided with sustenance
for its first days of life, is wrapped in a strong covering, and is pro-
vided with a wing, so that it can fly before the autumn gales, and
find fresh woods and pastures new. When the descendants of
these trees are so well started in life, a large proportion of them
will survive, and thus the oak, horse-chestnut, and maple families
are quite as well kept up as are the families of other trees, which
cast to the winds a large number of seeds less fully equipped for
the battle of life.

FAMILIAR FLOWERS. 295

By investigating the blossoms of the oak, horse-chestnut, and
maple, we see that these trees, ages ago, bore very many seeds,
which must have received but a scant provision a-piece wherewith
to start themselves in life. Under these circumstances, an immense
majority of the seedlings would die young, giving the parent plant
the expense of putting an enormous family out into the world, and
all to little purpose. To-day, evolution is teaching them " a more
excellent way."

" It is a fatal habit," says Grant Allen, " to picture evolution to
one's self as a closed chapter. We should think of it rather as a
chapter that goes on writing itself for ever. Our fields are full of
degenerate flowers- which retain some memorial of their old estate,
pointing backward, like the fasces of the Byzantine Emperors, to
the past glories of their race in earlier times." They are also full
of plants which bear somewhere about them half-obliterated traces
which tell the story of their progress from a lower to a higher form
of life ; for the changes brought about by atrophy may be either
progressive or retrogressive.

But atrophy, wherever we find its traces, proves to us one
thing, that nothing retains its place in the organism unless it makes
itself useful, or ornamental, or both, and that Nature tolerates no
shirks ; the moral of which, if moral there be, is tersely, though
inelegantly, expressed in the slang phrase, " You must hustle if you
want to be in it." And this is everlastingly, pitilessly true even of
the smallest herb which we crush beneath our feet.

Ants and Orchids. — According to J. H. Hart (Nature, liil,
627) the presence of ants seems to be essential to the well-being
of certain orchids. Whether the effects produced are directly due
to ants, or to some indirect cause, has not yet been determined.
The author is inclined to the opinion that the ants confer benefit
on the plant by providing it with the mycelium of a fungus to
cover its roots, this organism enabling it to take up food which
would otherwise be unavailable. It may be that the presence of
stinging-ants protects the plant ; but Mr. Hart thinks it is almost
certain that the fungus, which grows on the material that the ants
accumulate round the roots, plays an important part in the nutri-
tion of the plant by providing it with food material.

— Pharmaceutical Journal.

[ 296 ]

Sclectc^ notes from the motc^Boohs of the
postal riDicro6copical Society.

nD^rmecopbclou0 Heart.

By E. Bostock. Plates X. and XI.

I AM circulating in the present box a number of slides contain-
ing objects collected by myself during the early part of 1891,
and subsequently, in various localities, and, as I believe that
none of them have been previously sent round, I trust they may
prove of some interest to our members, especially as some of them
have only recently been described, and possibly one or two of
them may be altogether new.

They consist mainly of Myrmecophelous Acari, obtained from
the nests of ants of various species in the Riviera, Corsica, and
the Tyrol, and subsequently at home, as the result of various raids
upon the domiciles of the unfortunate ants. They serve to illus-
trate to some extent how very numerous are the varieties of other
creatures that are collected, protected, and nurtured by these for-
midable and omnivorous animals.

The question as to how they come to be found in the nests of
the various ants is an interesting one, and one to which I have so
far met with no satisfactory answer. Whether the ants carry them
there, or whether they happen along "promiscuous like," and com-
ing across the nests they find them comfortable abodes, and so are
induced to remain, is doubtful ; but one thing is quite clear, that
when they are there, they are certainly tolerated by their formid-
able hosts, and this probably on account of services rendered in
the shape of general scavengering or in some other manner. At
the same time, it is not a little singular that most of the different
forms are found associated with a particular kind of ant, and
though they may not always be met with in all nests of that one
kind, they are «<?/ met with, so far as my experience goes, outside
and away from these nests, and this would hardly be the case if
the Acari gathered from the surrounding neighbourhood into the
ants' nests in which they happen to be found. At the same time,
and be this how it may, I am inclined to the opinion that, so far

SELECTED NOTES. 297

as these gamasids are concerned, it is a case of pure toleration on
the part of the ants, because when their dwelHngs are disturbed
they show no signs of anxiety on account of their messmates,
whereas their flocks of aphides which may be exposed by the
removal of the covering of the nests are speedily attended to and
carried off to places of safety in the recesses of the same.

With the exception of occasional Oribatidce, these acarids
appear to belong to the family Gamasida, which is the most exten.
sive family, perhaps, of the Acaritm, and is considered at the same
time as the most highly organised.

The family GAMASiDiE is divided into four sub-families, viz. :
the Fieroptifm, which are found upon bats and allied creatures,
such as the flying-fox, etc.

The Derinanyssince, parasitic upon bats and birds.

The Gamasince, which are some of them parasitic in their
immature stages, whilst a larger proportion are entirely free-living,
active, predatory creatures ; and lastly,

UropodincB. — Of these also it may be remarked that many are
parasitic whilst immature, for they are frequently met with attached
to the legs and abdomen of insects in somewhat numerous clus-
ters, by what was at one time supposed to be a kind of umbilical
cord, and from which the family derives its name. This, again,
appears to be a case of semi-parasitism only, resorted to as a
means of conveyance to " fresh fields and pastures new," for no
nourishment can be obtained from the hard chitinous surfaces of
their temporary hosts.

The family Gamasid.« finds its place in the order Acarina,
having the abdomen entirely united to and fused with the cephalo-
thorax, and in the sub-order Metastigmata, in which the tracheae
open at the posterior part of the body, at the base of the legs ; a
skeleton having for base a sternum or ventral plate. Rostrum with
free, unarmed tactile palpi ; mandibles chelate.

The sub-family Uropodin/e is characterised by having a vent-
ral plate, united all round with the dorsal plate ; with excavations
for the legs, and perforated in front to afford passage to the mouth-
organs. The femurs of the first pair of legs are very much thick-
ened, and in a state of rest entirely cover the mouth-opening ; the
dorsal plate flatly arched.

International Journal of Microscopy and Natural Science.

Third Series. Vol, VI, u

298 SELECTED NOTES FROM

In the sub-family GAMASiNiE there are no excavations for the
legs, and the ventral plate is not entirely united with the dorsal, at
least in front, where a passage is left for the capitulum or tube
containing the trophi. The femurs of the first pair of legs are
wide apart, and are not thickened, as in the preceding sub-family.

The genus Lalaps is distinguished from Gamasus in that in the
former the second pair of legs are alike in both sexes, and rarely
bearing knobs or excrescences ; whilst in the latter the second pair
of legs are thickened in the male, and usually provided with
knobs and protuberances.

*TJropoda formicarise (Fig. i) was, I believe, first discovered by
Sir John Lubbock in his nests of Lasiiis flavus, and was described
for him by Mr. Michael in Ants, Bees, and Wasps, but the species
has never been figured because the specimens it was described
from were mounted in balsam, and he has been waiting until he
could find some fresh examples. This we have at last done in the
nests of the same species of ants {L. flavus), during a visit to
Forth Gwarra in Cornwall in October, 1892. They were met with
in some numbers on the upturned stones that covered the nests of
this ant, or rather upon some of them. It is a fine species, and
somewhat singular in having a considerable depression in the
upper hinder half of the abdomen, traversed by several transverse,
thickened, chitinous ridges. A massive chitinous plate projects
between the second and third pairs of legs on either side
apparently for their protection.

*Uropoda coccinea (Fig. 3). — This species was found by Mr.
Michael in the summer of the same year in the nests of Campo-
notus herculeaneus, near Innsbruck, Tyrol, in considerable numbers,
and was subsequently described and figured by him in a paper

* Since the above slides were circulated, a paper has been published by Mr.
Michael {Notes on the Uropodina, Jotirnal of the R.M.S. for June, 1894), in
which he gives a list of the British species, together v^^ith a revision of the clas-
sification and nomenclature of the same. The species marked with an asterisk
have their generic name altered to Glyphopsis, which differs from the genus
Uropoda in having the body irregular in form, the dorsum not regularly vaulted
or arched, but sculptured.

The fine species referred to above as having been left with Mr. Michael is
also described and figured by him in the same No. as Glyphopsis Bostocki.

THE society's NOTE-BOOKS. 299

read before the Zoological Society in December of the same year.
In the autumn of 1891 I was staying in Buxton, and there found
the same species also fairly abundant in all ages and both sexes in
the nests of Formica fusca under stones. When found alive the
creature is a deep crimson and very conspicuous upon the white
pupae of the ants, a position in which it was frequently met with ;
but after being killed and preserved, the colour fades until it
arrives at that of the present specimen. It is evidently very near
in character to

*irropoda (lamellosa?) (Fig. 7). — Mr. Michael considers this
species as doubtfully the "lamellosa" of Canestrini, but on com-
paring the drawing of the latter there is a marked difference, both
in the general contour of the creature and in the sculpture of the
upper surface of the abdomen, so that I am inclined to doubt that
it is so. This species was also found in some of the nests of L.
flavus in the neighbourhood of Forth Gwarra in Cornwall.

Fig. 4 (Uropoda campomoleudina) is found in the same nests as
the above.

Fig. 5 is another Uropoda of doubtful species, and is met with
in the nests of F. fusca very frequently attached to the legs of this
ant, the presumption in such cases being that such individuals are
about seeking another home, and so to form new colonies.

Including another very fine species of Uropoda — of which I
only found two specimens, which I left with my friend Mr. Michael
— -and CossinecE, also found at the same time, this makes six
distinct and well-marked species of this genus that I met with last
autumn in Cornwall, and there remain doubtless many others to
reward the pains of a diligent searcher.

Lselaps equitans (Fig. 10), also found in the nests of T. ccespitum
at the rear of Ajaccio, is a very different creature to the Uropoda
before named, which are all very slow and inert. It runs about
among the ants with the greatest activity, and in the general con-
fusion occasioned by the disturbance of the nest is consequently
difficult to capture. They might frequently be seen sitting upon
the heads of some of the ants, being thus carried about by them
in a temporary fashion, and disappearing with them into their sub.
terranean galleries. This species is also figured and described in

300 SELECTED NOTES FROM

the before-named Journal of the Zoological Society^ together with
Lcelaps Icevis and Lcelaps cuneifer.

Laelaps laevis (Fig. 8). — The former I obtained from the nest of
a ground ant, of name unknown to me. I met with it in one nest
only in the woods at the back of a village called Igis, near Inns-
bruck, Tyrol. It occurred in some numbers, together with great
quantities of a small Oribatid of the genus Notuspis, but of a
species unknown to me.

Laelaps cuneifer (Fig. 9) came from the nests of Camponotus
herculatieus, and was fairly plentiful in the large galleries con-
structed by this ant in the decaying trunks of fir-trees. With these
occurred also numerous other gamasids and oribatids, and in one
or two instances the curious chocolate-coloured larvae of a species
of breeze fly were comfortably ensconced in the same passages — a
somewhat singular locality for a fly to make its first appearance.
The colour and texture of the larva was exactly that of the gal-
leries in which it was found.

Fig. 1 1 is a LcBlaps I have been unable, so far, to identify, and
is probably undescribed. It came from the nest of an ant found
under stones in the olive groves at San Remo, of which I also
neglected to secure specimens for identification. The acari walked
leisurely about, holding their long front legs after the manner of
the chelae of chelifers.

Fig. 12 is a single specimen of a gamasid taken from the nest
of a ground ant in the Aahrenthal, near to the village of Patsch.
I have called it a Laelaps, but am very doubtful whether it does
not belong to another genus, and I also believe it will turn out to
be quite new.

Zetorchestesmicronychus (Fig. 6). — To complete the quotum
of slides, I have put in one containing several specimens of a very
interesting Oribatid, not as yet found in this country, but which
seems generally distributed on the continent — viz., Zetorchestes
mycronychiis, found amongst mosses. It is the only one in this
family that is known, so far, to be gifted with the ability to jump
like a flea, and is consequently difficult to capture, for as soon as
it is approached with a camel-hair pencil it gives a spring and has
disappeared. It will be noticed how deeply the coxae of the last

THE society's NOTE-BOOKS. 301

pair of legs are inserted into the walls of the abdomen, thus
giving great power of propulsion to these limbs. E. Bostock.

My friend, Mr. Bostock, having granted me the privilege and
pleasure of examining his slides and notes before their circulation,
I feel constrained to express my gratification, and also to congra-
tulate the P. M.S. that they have such a worker. If every member
pays as much attention to them as I have done, he will not find
the usual time too long for their investigation. There is so much
of interest and novelty, and it is no slight privilege to have a peep
at good mounts of rare, and even as yet undescribed, creatures.
I wish Mr. Bostock had given a minute and detailed account of
his raid on a good savage ants' nest. The idea makes me shiver.
Bees are bad enough ; but ants — ugh !

Uropoda formicarise (Fig. i) is a very fine species and well
worth figuring. I know Mr. Tuffen West is no longer to be num-
bered amongst the members, but I hope that his mantle has fallen
on some other member, who will find plenty of employment for
.his pencil whilst the box is with him, or I would suggest that some
photographic member should do his best with these mounts.

Uropoda canestriniana is a much smaller, but equally distinct
species.

TJropoda coccinia is described and figured by Mr. Michael in
his paper on the " Association of Gamasids with Ants " in the
Proceedings of the Zoological Society, Dec. i, 1891.

The two next Uropodas are small, but very distinct and beau-
tiful species, well worthy of being figured. One thing strikes me,
and that is that all these new species are so different in form and
so much smaller than the old ones, with which one is so familiar,
such as Vegetans, Cassideces, etc.

Laelaps equitans. — This beautiful mount reminds me of one of
Z. hilaris, and Koch says that these mites live a very long time in
captivity, but are never still. When Koch wrote, only four species
of Lgelaps were known. All these were parasitic on mites, and all
of them were very similar in figure. In this box we have no less
than five species, all diftering from those he described, and the
four last of them not giving one the idea at first sight that they
belonged to Lcelaps at all. I wish I had a good English transla-

302 SELECTED NOTES FROM

tion of Koch's work, but have never heard of one being made.

C. F. George.

Notes and criticisms from one who has not a competent know-
ledge of the subject are useless and unimportant. I know nothing
about " Mites," and therefore shall not attempt to say anything
about Mr. Bostock's valuable and interesting slides. I can only
thank him for the circulation of such a carefully prepared set, so
instructive and suggestive, It is not often we get any obtained by
so much travel and trouble. The whole subject of the various
lodgers in ants' nests deserves investigation by some competent
naturalist. It is one on which Darwin might have written nobly.
Sir John Lubbock speaks of certain beetles which live in ants'
nests, and suggests, if I remember right, that they may be objects
of worship ! I could wish Mr. Bostock had said something more
about the structure of Acari, and I should like to know how he pre-
served them before mounting. Are they put when caught at once
into turpentine or acetic acid ? I have been looking at what
Nicholson says about Mites. Does he not confuse Mites with
Ticks ? Are not mites near akin to spiders — creatures with eight
legs? Are not ticks insects '^'x'Ca six legs (like the sheep tick) —
degenerate flies, in fact, which have lost their wings ?

R. S. Pattrick.

I am grateful for the privilege of examining these notes, and
have found them of great assistance in gaining a little knowledge
about these creatures. I should like to know more definitely than
I have been able to gather from the notes the functions of the
Acari in the nests, and also how such objects are caught and pre-
served, as I can hardly imagine them so plentiful as to be found
upon every ant that may be caiight. W. S. Ingram.

I am glad to find the accompanying slides have proved of
interest to some of our members, and also that they have borne
their travels so satisfactorily. Before starting them again, I take
the opportunity to reply to the Rev. R. S. Pattrick's query as to
how they are preserved {i.e., the acari) before mounting. My
general plan when practicable is to place them in a saucer of water,
then kill them in boiling water, from which they are transferred to
slightly dilute acetic acid. This keeps them in fair condition for
subsequent treatment for some time.

Journal of Microscopy 3 - Ser Vol. G, Plate 10.

tt a I

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3.

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..=.^ >. f:Ph,//ios c/efeiSc

Myryrv&cophiloW'S Aoa^rc-.

Journal of Microscopy o- Ser. Vol. 6, PlaLc 11

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11. ^jQ^ "'^'-

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THE society's NOTE-BOOKS. 303

Ticks.— Nicholson is quite correct in placing Ticks among the
Acarina, of which order they constitute a considerable family,
under the title IxodidcB, which includes Argus also. The Sheep-
tick (so called) is not a tick at all, but a degraded fly. It has only
six legs, in common with other insects, whereas the Ticks and
remaining families of the Acarina have all eight legs, barring
certain degraded forms. I think, however, the main point of dif-
ference between the different families have been more than once
pointed out in our Note-books by myself, and it seems superfluous
to repeat these matters with each fresh box.

I am afraid I cannot enlighten Mr. Ingram more definitely as
to the functions of the Acari that avail themselves of the shelter
of the nests of ants, beyond stating that they are probably induced
to remain there because of the food picked up amongst their hosts.
Again, they probably act as scavengers ; but I feel doubtful as to
whether any more intimate connection exists, or that they are
there on any other principle than that of toleration. It is true,
however, that they are not found indiscriminately in a// ants' nests,
and.that certain Acari appear to be associated with certain kinds
of ants.

The thanks of the Society are due to Miss F. Phillips for her
nicely-executed drawings. E. Bostock.

EXPLANATION OF PLATES X. and XI.
Plate X.
Fig. 1, 1. — Uropoda formicarice, $ and 5 •
,, 2. — TJ. canestriniana, 5, x 50.
,, 3. — U. cocdnea, 9 , ^ 50.
,, 4. "1 l/". (? sp.), (J, from nests of F. flava.

5. ]u. (?sp.), c?, ditto.

,, 6. — Zeterchestes micronychus, x 50.

Plate XI.
,, 7. — Uropoda laminosa (? sp.), ^j ^ 50.
,, 8.— Lcelapn Ictvis, (J, x 50.
,, 9. — L. cunifer, (J, x 50.

,, 10. — L. equitans, x 50.

„ ll.-i. - (? sp.).

„ 12.-i. - 0 sp.)-

304 SELECTED NOTES FROM

Coniferous Wood from Coal Measures (vert. sec). — Traces of
the glandular tissue (peculiar to the cone-bearing trees) can be
found in many parts. But the principal interest in the specimen
lies in the fact, that while in the condition of ordinary wood, it
was perforated by the larva of some insect, and that the perforations
have been left filled ivith excreta, just as we should find a bit of
worm-eaten wood of the present day. W. Pumphrey.

No doubt the black, roundish bodies in the cavities are the
remains (carbonised) of the animal which burrowed, but it seems
to me doubtful if they are excrement. If so, the animal produced
a bulk about equal to himself, and the several pellets are large in
proportion to the size of the larva, which would not have been
larger than the cavity it occupied ; and if these are all excremen-
titious, what has become of the animal itself? Possibly I may be
answered that the animal has come to maturity and crawled out,
leaving its excrement, but in that case we may suppose the latter
would have been at one end of the cavity and not distributed all
through it. G. D. Brown.

I do not think the above an improvement of Mr. Pumphrey's
explanation of his slide. From observations of similar burrows
in wood, I am convinced that those in the slide are, as Mr. P.
says, filled with excreta, just as we should find a piece of insect-
eaten wood at the present day.

The rounded bodies are not remains of the animal itself, but
its excreta, which are likely enough to fill the burrow. The larva
can only progress by passing every particle of the excavated
material through its intestines. A. Hammond.

Cyclostoma elegans, Palate of. -This small snail is common in
most chalky districts ; its shell is closed by an operculum. The
palate contains seven rows of teeth, and is different from that of
the other land-snails. M. Farhall.

Cyclops quadricornis.— I direct particular attention to the three
eyes or lenses. I protest against the word facets, as applied to
them. It will be found that the two upper eyes are directed
respectively to the right and left, whilst the under one is straight-
forward, though probably it may be used to view objects imme-
diately below it approaching the mouth.

THE society's NOTE-BOOKS. 305

The eyes should be examined in various lights ; arrange the
condenser properly, and the eyes will shine like opals. How is it
these eyes are so much more brilliant than those of insects ?

R. K. CORSER.

Ditto. — I have not minutely examined the eye of cyclops, but
comparing Mr. Corser's slide with my own observations on Diap-
tomus Castor, I am certainly inclined to support its triple nature —
i.e., I think it consists of three crystalline lenses (not facets, for
facets are cuticular structures, whereas the lenses are derived from
the epidermis). I think it highly probable that the structure of the
eye in Cyclops and Diaptomus is essentially similar to that of
Daphnia, differing mainly in the fewness of the lenses.

A. Hammond.

Cyclops. — In the new edition of the Micrographic Dictionary,
Cyclops is said to have a sino^le central eye ; but Huxley, in his
Invertebrata, says there are two simple eyes together within the
carapace. Nowhere can I find mention of three ocelli.

T. GOUGH.

Ditto. — Carpenter states that " this genus receives its name
from possessing only a single eye, or, rather, a single cluster of
ocelli. The slide enclosed in this box certainly shows three ocelli,
whatever may have been written to the contrary. From Mr.
Gough's remarks, it seems that one noted scientific man alleges
that this Crustacean has two simple eyes. I wonder what he would
say of this slide if it came under his own eye. Gosse, in his
Evenings at the Microscope (ist edit., p. 216), states that "the eye
of Cyclops is elaborately constructed ; for it consists of a number
of (not very large) simple eyes placed beneath a common glassy
cornea. Several muscle-bands are attached to this compoutid
organ of vision, and are arranged so as to form a cone, of which
the eye is the base ; these give the eye a movement of rotation
upon its centre, which may be distinctly seen."

I am inclined to think that previous observers were not so
much in error as Mr. Corser seems to imply, but that they were
not sufficiently precise. They noted that the eye of the creature
was situated /;/ a single spot — hence the allusion to the fabled
monsters of classic history. More modern observers, as quoted

306 NOTES FROM THE SOCIETY'S NOTE-BOOKS.

above, have asserted what is no doubt the true state of the case.
The so-called single eye is really a chister of ocelli. R. H. Moore.

Calathus cisteloides.— This beetle is iigured in Rev. J. G.
Wood's Common British Beetles and named C. cisteloides., and is
described at p. 34 as follows : —

" The length of this insect is raiher under half-an-inch. It is
one of the dull-coloured species, as are indeed almost though not
all beetles which live in dark retreats and only venture into the
open air at night. It is almost entirely black, but the basal joint
of the antennae and the legs are red. Sometimes even the legs
partake of the general black hue of the body.

The disc of the thorax is extremely wrinkled, and there is a
large oval impression on either side of the base. If is narrower
in front than at the base. The head is very smooth and convex
behind, and has a small furrow on either side between the antennae.
This is one of the wingless genera, the second or membranous
pair of wings being undeveloped." H. W. Lett.

Coleus, Leaf and Glands. — The red beads on the leaf of Coleus
are the essential oil-glands. Similar appendages will be found on
the leaves of the common Myrtle, the Mints, Sweet Briar, Euca-
lyptus, and Garden Lavender ; all of which yield a perfume more
or less readily when bruised or crushed, which ruptures the Uttle
vessels and the essential oil escapes. H. W. Lett.

The slides illustrating the essential-oil glands in the leaves of
plants are most interesting. Some species of Citrus have them as
fully developed as Hype7iciim perforatum, about which latter plant,
by the way, an old legend relates that the minute holes are formed
by the devil with his needle. E. E. Jarrett.

Coal Section. — The slide so marked is incorrectly named, but
the error is by no means uncommon, as almost all dealers supply
similar sections under the same name. Still, as the substance
sectioned is Lignite, the title is partly correct, as it is the coal of
the Tertiary period. It contains much more bitumen than our
own coal of the carboniferous period, is also much softer, so much
so that it can be easily cut with a knife. It has a dull, earthy
appearance, and has no "joints" in it.

REVIEWS. 307

It is not at all wonderful that under the microscope it should
show woody structure, as fragments of wood, and large ones too,
are abundant in it, and so little decomposed some of them are,
that they require to be cut with a hatchet in some cases. At least,
such was the case at a mine which T visited this summer at Diirn-
ten, near the lake of Zurich, Switzerland. An interesting discus-
sion on the subject of making "Coal-Sections" appeared in
Science Gossip in 1882, beginning in the April No., the gist of
which is that sections of house-coal are almost impossible to make,
and even when made show very little structure. The instructions
for making Coal-Sections, as given in the Micro. Dictionary., are
perfectly useless as applied to house-coal ; it is simply wasted
time to try to follow them. Some persons, however, can prepare
them by a process of their own. I obtained one from Herr
Heinrich Hensoldt, 7 Machell Road, London, S.E., a very skilful
preparer. James C. Christie.

1Rcvicw0,

A Text-Book of Pathogenic Bacteria for Students of
Medicine and Physicians. By Joseph McFarland, M.D. Royal 8vo, pp. 359.
(London: H. Kimpton, 1896.) Price 12/- net.

In this handsome volume the author gives a concise account of the techni-
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and Co. 1896.) Price 7/6.

A very useful packet companion for the country rambler, its purpose being
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contains coloured figures of 156 species, black-and-white plates of 22 species,
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The instructions here given, which take the form of talks with young
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These parts contain the Rutaceae, Simarubaceas, and Burseraceae, by A.
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Allen and Co. 1896.) Price 6/-

This vol. of Allen's Naturalists' Library continues the description of the
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pp. X. — 253. (London: A. and C. Black. 1896.) Price 5/-

Mr. Witchell, author of " The Fauna of Gloucestershire," has given the
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This is an admirable book for the identification of Butterflies and Moths,
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This vol. of •' Allen's Naturalists' Library " completes the survey of the
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REVIEWS. 309

The Royal Natural History. Edited by Richard Lydek-
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Part 31, the last part of this fine work which has reached us, is the first
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Nature's Wonders. By Edith Carrington. Cr. 8vo, pp. 216.
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An interesting account is here given of Wonders of the Air, Wonders by
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the various standards, the volume before us being for Standard V. All young
people must like to read these books.

The Aquarium : Its Inhabitants, Structure, and Management.
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Those interested in the life-histories of Aquatic Animals will do well to
read this little book, a sixth edition of which is now before us. Amongst its
various chapters will be found instructions for Constructing both Marine and
Fresh- water Aquaria, and how to stock them and keep them in order. There
are 239 illustrations.

Artistic and Scientific Taxidermy and Modelling : A

Manual of Instruction in the Methods of Preserving and Reproducing the
Correct Form of all Natural Objects, including a Chapter on the Modelling of
Foliage. By Montague Browne, F. G.S., F.Z.S., etc. Fscap. 4to, pp. xii. —
463. (I<ondon : A. and C. Black. 1896.) Price 21/-

This important work treats the subject of Taxidermy and Modelling in a
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There are 22 plates and 1 1 illustrations printed in the text. The volume is a
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Nature's Byepaths : A Series of Recreative Papers in
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This is one of the most interesting books written by Dr. Taylor, the late
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Subterranean Mountains; Soils, their Origin, Renovation, and Decay; A
Naturalist on the Tramp ; The Geological Dispersion of Animals and Plants ;
Aquatic Engineers ; Vegetable Parasites ; etc. etc.

Mathematical Questions and Solutions from the Educa-
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Edited by W. J. C. Miller, B.A. Vol. LXIV. 8vo, pp. 128. (London :
Francis Hodgson. 1S96.) Price 6/6; to subscribers, 5/-

Intermediate Science. Mixed Mathematics Papers, being
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310 REVIEWS.

The Intermediate Algebra, based on the Algebra of Rad-

hakrishnan. By William Briggs, M.A., F.C.S., F.R.A.S., and i\. H. Bryan.
Sc.D., F.R.S., etc. Cr. 8vo, pp. vii.— 375. (London : W. B. Clive. 1896.)
Price 3/6.

We learn by the Preface that Prof. Radhakrishnan's book is the outcome of
the intelligent digestion of the best English authorities, particularly of De
Morgan, Clifford, and Chrystal, and in the book before us the Indian work has
been subjected to numerous alterations and modifications, and considerable
additions have been made (notably. Logarithms, Interest, and Annuities) to
render it more suitable to the wants of English students. These last-named
chapters are entirely new ; a new method is introduced of treating annuities
-(.vithout employing the formula for a geometrical progression.

A New English Dictionary on Historical Principles, edited
by Dr. James A. H. Murray. Fieli:) — Fish. By Henry Bradley, Hon. M.A.
Oxon. (Oxford: The Clarendon Press. London: H. Frowde. April, 1896.)
Price 2/6.

The present section is concerned with words that are among the oldest and
most frequently used in the language. This part contains 766 main words,
of which 5S6 are current and native or fully naturalised, and 161 (or 27 '4 per
cent.) are obsolete. There are also 553 combinations and 97 subordinate,
making 1416 in this section.

The Oracle Encyclopaedia, containing the most accurate

information in the most readable form. (London: George Newnes.)

Part 19 of this work commences the fourth volume. Commencing with
London, it carries on to the word Medici. This part consists of 120 pages.
There are many illustrations.

A Popular Handbook and Atlas of Astronomy : Designed
as a Complete Guide to a Knowledge of the Heavenly Bodies, and as an Aid
to those possessing Telescopes. By William Feck, F.R.S. E. , F.R.A.S., etc.
Large 4to, pp. xii. — 176. (London and Edinburgh: Gall and Inglis. 1890.)
Price 21/-

In this fine work the various subjects are described in a popular manner,
complete and accurate information being at the same time given in the principal
departments of modern astronomy. The aim of the author has been to supply
the knowledge that is required by every fairly-well educated individual — viz.,
to give a clear, accurate, and popular account of the nature of the various
heavenly bodies and their position in the universe.

In the first chapter, in a condensed form, is presented the Author's investi-
gation as to the origin of the Constellations ; these are the outcome of many
years' study. The principal subjects discussed in the various chapters are
arranged under various heads

We believe the Atlas will be found to be of the greatest assistance to all
who are desirous of obtaining an accurate knowledge of the sidereal heavens,
and have great confidence in recommending it to our readers. There are 45
large plates, maps, etc., and many illustrations, diagrams, etc.

Historical and Future Eclipses, with Notes on Planets,
Double Stars, and other Celestial Matters. By Rev. S. J. Johnson, M.A.,
F.R.A.S. Crown Svo, pp. viii. — 178. (London : James Parker. 1896.)

We have in the first part of this book a brief account of some very early
Chinese eclipses, and of the most ancient eclipses of which we have clear
record, eclipses in the Christian era, and a long list of future eclipses extending
to A.D. 2491, with diagrams; Part 2 contains interesting notes on Planets,
Double Stars, and other celestial matters.

REVIEWS. 311

The Story of a Piece of Coal : What it is, Whence it
comes, and Whither it goes. By Edward A. Martin. Fcap. Svo, pp. 179.
(London: G. Newnes. 1896.) Price l/-

This volume of the " Library of Useful Stories" brings together the prin-
cipal facts and wonders connected with a piece of coal into the focus of a few
pages, where side by side will be found the record of its vegetable and mineral
liistory, its discovery and early use, its bearings on the great Fog problem, and
its useful illuminating gas and oils. These little books are deserving of much
praise.

The Story of Electricity. By John Munro. Fcap. Svo,
pp. 194. (London : George Newnes. 1896.)

This is another volume of Sir George Newnes' very capital " Library of
Useful Stories." It describes in very plain language the Electricity of Friction,
of Chemistry, of Heat, and of Magnetism ; Electrolysis ; the Telegraph and
Telephone ; Electric Light and Heat : Electric Power ; and the Minor Uses
of Electricity. There are 100 illustrations. A useful list of books relating to
Electricity, with the published price of each, is given. We trust this series of
story-books may be greatly extended.

The Photographic Reference-Book : Hints, Information,
and Methods concerning all kinds of Photographic Work and Recreation.
Compiled by W. A. Watts, M.A., under the direction of Henry Sturmey,
editor of Photography. 8vo, pp. 300. (London : Iliffe and Son.)

A very large amount of information is contained in the 300 pages of this
book, which is essentially a worker's handbook, the keynote of the volume
being hotv to do everything in connection with photography.

The Year-Book of Photography and Amateur's Holiday
Guide for 1896. Cr. Svo, pp. (about) 400, or counting Advertisements 628.
(London : The Photographic News.) Price l/-

The various sections into which this book is divided treat of Progress and
Practice, Facts and Formula;, The Amateur's Holiday Guide, Lanterns and
their Accessories, and Novelties of the Year. It is a thoroughly good shilling's
worth, well illustrated by plates and smaller illustrations.

The Gospel of Buddha according to Old Records, told by
Paul Carus. Fourth edition. Cr. 8vo, pp. xvi. — 275. (Chicago : The Open
Court Publishing Co. 1896.)

Dr. Carus tells us that the bulk of the contents of this book is derived from
the old Buddhist canon. Most of the passages are literally copied from tran-
slations of the original texts. Buddhism appears to be split up into innumer-
able sects, but the present book follows none of the sectarian doctrines. It
takes an ideal position, upon which all true Buddhists may stand as upon
common ground.

Black's Guide to the English Lakes. Edited by A. R.

Hope Moncrieff. Crown 8vo, pp. x. — 223. (London : A. and C. Black.
1896.) Price 3/6.

This edition (the twenty-second) will be found to be practically a new work,
it having been re-written and re-cast. It is divided into the following sections,
viz. — Windermere, Ullswater, Central, Keswick, and Coast sections. There is
a large map of the Lake District in pocket at the end of the book ; also, a
number' of Section and District maps.

312 REVIEWS.

Pleasure-Cycling, by F. T. Bidlake ; with Helps to Riders,

by Sennocke. Cr. 8vo, pp. 32. (London : Iliffe and Son. 1896.) Price l/-
In these 32 pages the author finds something to say on the pleasure and
healthy exercise of cycling. He gives hints to riders on choosing a machine,
learning to ride, etc.

The Practice of Cookery and Pastry adapted to the busi-
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pp. xvi. — 359. (Edinburgh: Andrew Elliot. 1896.)

This little book contains a large number of practical and useful receipts on
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Preserves. The author appears to have taken pains to make his directions as
clear and distinct as possible, both as regards quantity of ingredients and time
required for cooking.

Messrs. Cassell and Co. have sent us the following : —

Cassell's Concise Cyclopedia. Parts I., II., III. 6d. each.

Commencing with A, these parts carry to Daddy Long-Legs, for a descrip-
tion of which the reader is referred to Crane-Fly. The descriptions are short,
concise, and to the purpose. There are two plates and a number of smaller
illustrations in each part.

Cassell's Natural History, Parts i, 2, and 3. Edited by
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We are pleased to know that Messrs. Cassell are publishing a remarkably
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natural history of the Apes and Monkeys and of the Lemurs, by Prof. Martin.
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Contains most interesting papers on every department of science. Part 7
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Chums. 6d. monthly.

Two new serials are commenced in the June part. Prizes are offered by
the editor for which our young friends would do well to compete, even if they
are unsuccessful.

[ 313 ]

Briti6b 1bv>^racbni^a:.

By Charles D. Soar. Part VI. Plate XVI.

'^r^'^.-^^ Genus VI. — Diplodontiis (Duges).

N the present paper we propose to direct attention
to a genus which differs considerably from that last
described.

1834. — Diplodontiis, Duges, " Remarques sur la
famile des Hydrachnes " in A?males des
Sciences. Nat., Tom. I., p. 144.

Body soft-skinned ; legs well-supplied with swim-
ming hairs ; claws to all the tarsi. Epimera in four
groups. Palpus short and chelate. Eyes four, two
on the Dorsal and two on the Ventral side, near the margin of
body. The genital plates on each side of the genital fissure are
covered with numerous genital pores.

This genus differs verylmuch from the last which we considered.
At present I only know of one species in England, although I
have taken three varieties of it in as many different localities.
This Hydrachnid is very common ; I have secured as many as
forty specimens in one day's collecting. I consider there are three
varieties, because, although all are identical in structure, the
colouring of the three varieties is distinctly different.

Diplodontus despiciens (Mull.).
Bibliography.
1 78 1. — Hydrachna despiciens, Miiller, Hydrachnce, p. 58, Plate VI.,
Fig. 8.

1834. — Diplodontus filipes, Duges, " Remarques sur la famile des
Hydrachnes," in Annales des Sciences, p. 158, Plate X.,
Figs. 1—4.

i2>^j\.— Diplodontus filipes, Bruzelius, Beskr. 0. Hydrachn. som.
forek. i. skane., p. 44, Tab. IV., Figs. 9 — 12.

1878. — Diplodontus filipes, Krendowsky, Die Metamorphose Hy-
drachnidcB, p. 8, Plate I., Figs, 3 — 4.

International Journal of Microscopy and Natural Science.

Third Series. Vol. VI. v

314 BRITISH HYDRACHNID^.

1880. — Diplodontus filipes, Newman, Sveriges Hydrachnides, p. 108,

Tab. XIII., Fig. 3.
1882. — Diplodontus filipes, Haller, Hydrachniden des Schweiz, p. 47.
1885. — Diplodontiis filipes, Krendousky, HydracJmidcE of Russia,

p. 123, Figs. 16 — 20.
1896. — DipJodontus despiciefis, Koenike, Farschungolerischte aus der

Biologischen Station zu Flofi.

The first time I made the acquaintance of this Hydrachnid
was at the Warren, Folkestone, in July, 1894; it is a very beautiful
mite. The body is an ellipse in shape ; sometimes it is more
rounded than at others ; it also varies very much in size, some
females being quite twice the size of others ; its average length is
about 5/60 of an inch. The colour of the body varies very much,
some being a brilliant red, whilst others are of a dirty yellow, and
all intermediate shades. The whole of the surface of the body is
covered with small papillae. The dorsal surface is also strongly
marked with a number of brown patches, sometimes radiating from
the centre, and at others apparently in confusion and running in
all directions. Eyes four, two showing plainly on the dorsal
surface, and two on the ventral ; the upper pair project and stand
out in bold relief like glass beads. The legs are not very long,
but are well supplied with swimming hairs ; all the tarsi have claws.
The colour also varies very considerably. I have found some with
the legs of the same brilliant colouring as the body, whilst the legs
of others have hairs of a bright yellow ; so marked has been this
distinction of colour in some cases, that I at first thought I had
found a distinctly different species, but the structure in all cases
has been identical. The palpus is chelate (see Fig. 5). In the
larger specimens the mouth organs are so far under the body that
the palpi cannot be observed from the dorsal side, but in the
smaller specimens the last joint only can sometimes be seen.
The genital plates are close up to the genital fissure, and are
covered with a great number of raised dots. These dots are very
small, but they are exceedingly numerous. I can distinguish no
great distinctive difference in the sexes, except that which is seen
in the genital fissure, as shown at Figs. 7 and 8, Plate XVI.

These interesting little creatures will live well in a tube at

Journal of Microscopy if- Sen Vol, 6, Plate 16.

s %w\ \

. Mil V:i^

I

^r \\

Diplodontus despLCL&ns /^r?z7j.U.J

BRITISH HYDRACHNID^. 315

home, if the water is kept in good condition with pond weed. I
have been fortunate enough to breed the larva. On June ist this
year I put a dozen Diplodontus despiciens adults into a tube by
themselves, and on June 4th a quantity of ova was deposited on
the side of the tube. The eggs or nuclei were embedded in an
outer protoplasmic matter, in the same manner as I described in
the paper on JVescea. They were of a deep cadmium colour, the
gelatinous-looking film being almost colourless. They passed
through similar stages to those previously mentioned, and
hatched out on June i6th. Their first object in life seemed to be
to get out of the water and into the world as quickly as possible ;
they ran about like so many minute red spiders.

The movements of these little creatures were much more
energetic out of the water than in, and I found some difficulty in
getting one into a suitable position to draw (Fig. 4 is drawn from
one in the life). It has four eyes on the dorsal surface, as shown
in the drawing ; six legs only, which is usual in the larval stage ;
the tarsi is broad at the widest part, and thin at the claw end ; the
claws; two in number, are curved backwards (see Fig. 6) ; the tarsi
is covered with a quantity of long pectinated hairs. The colour
of the larva is pink. Palpus is chelate, same as adult.

I have not been able to carry my investigations further than
the larval stage, but have taken several specimens of the nymph,
which is supposed to be the next stage, at Bealings this year
(Fig. 3, in which note the arrangements of the genital pores) ; and
at some future time I hope to be able to note and describe the
whole life-history of these very interesting creatures from the ova
to the adult.

Krendousky, in his work 1878, gives a very good outline
drawing of the larva of this Hydrachnid. Miiller's small figure
of the adult is very good. Newman's figure is a beautiful drawing
in colour, with red body and yellow legs.

EXPLANATION OF PLATE XVI.

Diplodontus despiciens (Miill.).

Fig. 1. — Ventral surface of adult.
,, 2. — Dorsal surface of adult.

316 THE BINARY STARS.

Fig. 3. — Ventral surface of nymph, showing the difference in the gen-
ital area at this stage, and at that of the imago.

,, 4. — Dorsal surface of larva, drawn from a specimen hatched the
same day.

,, 5. — Palpus of imago.

,, 6. — Tarsi and unguis of larva, showing the pectinated hairs.

,, 7. — Genital plates of 9 •

,, 8. — Genital plates of ^.

Zbc Binary Stars,''

By H. Wyles, L.D.S., Leeds.

SCATTERED throughout space are numbers of stars which,
upon examination with the telescope, are seen to be double,
two stars being visible where to the unaided eye there only
appeared to be one. These double stars offer a great variety of
appearances to the observer, the two components in some cases
being widely separated and in others very close together, so that
their separation requires a telescope of great size and perfection.
Then, again, they are sometimes composed of two stars^. of the
same apparent degree of brightness or of the same colour, and
others appear of widely different magnitudes and of very different
colours. They have been most carefully observed by astronomers
for more than a hundred years, and they have yielded in return
results and information of the most important and interesting
nature. Who would have believed at one time that we should
ever be able to weigh a star and say what its mass might be when
compared with our own earth or with the sun ? Yet this is only
one of the results which assiduous observation of the binary stars
has enabled astronomers to achieve.

The name of " binary " is only applied to those double stars in
which the two components have been shown to have a physical
connection with each other, and to form a pair which are really
very near together in comparison with the immense distance which

*A paper read before the Leeds Astronomical Society March nth, 1896.

THE BINARY STARS. 317

separates them from us. Of course, it is certain that there are
many stars which appear double when viewed with a telescope, in
which the close proximity of the pair is merely apparent and not
real, the two stars not being in any way connected with one
another, one being immensely more distant than the other, and
their apparent nearness to each other being merely due to perspec-
tive, both happening to lie very nearly in the same line of sight.

On the other hand, there are large numbers of double stars in
which careful and persistent observation has brought to light the
fact that both the components are moving in concert, and are in
fact two suns performing revolutions round each other, or rather
round the common centre of gravity of the pair, and it is these
movements of revolution which have been made to yield such
important results. Perhaps it will be best to divide the double
stars into four classes : —

First, the binary stars proper, in which movements of revolu-
tion have been detected, such as Castor, 61 Cygni, and Sirius.

Second, pairs in which no such movement has been discovered
(owing, perhaps, to its being too slow to be noticed), but in which
a common proper motion of both components through space
along parallel lines and in the same direction is found, rendering
it more than probable that some physical connection exists
between the pair — Mizar and its companion, together with Alcor
in Ursa Major, may be taken as examples of this class.

Third, those doubles which are distinguished by quite opposite
characteristics, and in which no movement of revolution can be
detected, and where the proper motion of one is not participated
in by the other. Vega is an instance of this class of star.

Our fourth class consists of those stars which — although we
cannot see that they are double, and which no telescope in the
world will show as more than a single point of light — we yet know
by a process of reasoning (which is as certain in its results as
ocular demonstration) to be really double, and to be composed of
two suns revolving round one another, but placed so close together
in comparison to the immense distance at which they are situated
from us that the spectroscope alone is able to divide them, and to
afford us proof of their double character. The primary star of the
Mizar system (which, when taken together, has supplied an

318 THE BINARY STARS.

example of our second class), if taken by itself, affords an example
of this fourth class, as it is found to be a splendid spectroscopic
double.

It is with stars of our first class, or binaries proper, in which
revolution of the pair is visible, and of the fourth class, or spectro-
scopic binaries, in which the spectroscope declares revolution to
exist, that we are now principally concerned. It was, I believe,
Sir William Herschel who first discovered this movement of revo-
lution more than a hundred years ago, and since that time some
of these pairs have been watched through more than one complete
revolution. It is not my intention to attempt the description of
many of the binary stars separately, for their name is legion. I
shall only single out one or two, and use them as examples to
show the main principles of the methods of research which have
been adopted, and the results which these researches have led to.

In the first place, when by observation we have learnt the time
of revolution of the smaller star around the larger — or, rather, of
the pair round their common centre of gravity — we can, if we also
know the distance at which they are situated from us, tell the mass
of the pair as compared with the mass of the sun. We will take
Sirius as an example of this. The presence of a large and massive
companion revolving round Sirius was suspected long before this
companion was ever actually seen. It had been observed that the
proper motion of Sirius was somewhat irregular, and it was confi-
dently predicted by the illustrious astronomer, Bessel. that this
irregularity of movement would be found to be caused by the
disturbing influence of a large but comparatively faint companion^
and this has since proved to be the fact. This body, which (like
the planet Neptune) was known to exist before it was ever seen,
owing to its perturbing influence upon the movements of Sirius,
was first observed in 1862 by Alvan Clark, jun., one of the cele-
brated firm of American opticians, when testing a new and power-
ful refracting telescope which they had been making. I believe
the object-glass of this telescope which first showed the companion
to Sirius was eighteen inches in diameter, but it has since been seen
with telescopes of much less size, for it is always found to be the
case that when an object has once been discovered, observers pro-
vided with much smaller telescopes than the original discoverer

THE BINARY STARS. 319

are able to see it. Many careful observations and measurements
of the movements and positions of this companion to Sirius have
now been made, and it has been found almost exactly to fulfil
Bessel's prediction. It has been ascertained that it completes its
revolution round its primary in about forty-nine years ; also, as the
distance of Sirius from us is approximately known, the actual
distance in millions of miles which separates the pair can be cal-
culated when their mean angular distance from one another in
seconds of arc has been accurately measured. Now, taking the
distance of Sirius from us at loo billions of miles, an apparent
mean angular separation between him and his companion of one
second of arc would represent an actual distance between them of
about 484 million miles.

When a number of careful measurements of the relative posi-
tions and angular separation of two stars have been made extend-
ing over a sufficient lapse of time, it is possible to map out the
shape of the orbit which each is pursuing as seen from the earth,
and to estimate approximately their mean angular distance from
each other expressed in seconds of arc. There are some slight
discrepancies in the various estimates of the mean angular dis-
tance separating Sirius and his companion as given by different
observers ; but it seems probable that this cannot differ much from
seven seconds of arc. If, then, the mean distance separating
Sirius and his companion is seven seconds as seen from the earth,
then, as one second at the distance of Sirius represents, as I have
said, 484 million miles, seven seconds will indicate an actual mean
distance between the pair of 3388 million miles, or rather more
than thirty-six times the distance from the earth to the sun. We
are, therefore, able to make a comparison between Sirius and his
companion on the one hand, and the sun and the planet Neptune
on the other.

Now, Neptune is about thirty times as far from the sun as the
earth is, and we will imagine that another planet existed in the
solar system at the same distance from the sun as that which sepa-
rates Sirius and his companion. Now, taking the earth's distance
from the sun as unity, Neptune's would then be represented by
the number 30, and the distance of our imaginary planet would
then be 36. We know that Neptune completes the circuit

320 THE BINARY STARS.

of his immense orbit in one hundred and sixty-five of our years,
and by bringing Kepler's third law to bear upon the problem, we
can easily discover what the period of revolution of this imaginary
planet would be, situated at a distance from the sun represented
by the number 36, as compared with Neptune, whose dis-
tance we represent by 30. Kepler's third law says that the square
of the periodic time of a planet in the solar system always
bears the same relation to the cube of its distance as in the case
of any other planet, so that the square of the periodic time of our
imaginary planet must bear the same relation to the cube of its
distance (36) as the square of 165 (Neptune's periodic time) bears
to the cube of Neptune's distance (30).

Now, if we work this out, we shall find that if such a planet
existed in the solar system at the distance we have assigned to it,
it would take about two hundred and seventeen years to revolve
round the sun. But the companion to Sirius completes its revo-
lution in forty-nine years ; we therefore see that it revolves very
much quicker in comparison to its distance from its primary than
do the planets of the solar system ; and we know that the greater
the attraction of a central sun the quicker all its planets must
revolve in order that they may not fall into it. It is evident,
therefore, that the mass of Sirius must be much greater than that
of the sun.

The law of gravitation, as discovered and explained by Sir
Isaac Newton, tells us that the square of the time of revolution
of any planet varies inversely as the gravitational pull existing
between itself and its central sun, and the gravitational force
exerted by two bodies upon each other at a given distance is
directly proportional to their joint masses. Therefore, the mass of
Sirius together with his companion, is to the mass of the sun and
his imaginary planet as the square of 217 is to the square of 49 ;
that is to say, about nineteen times as great.

Now, the masses of the planets of the solar system are almost
inappreciable when compared with the mass of the sun. The
mass of our imaginary planet may therefore be left out of our
calculation, and we therefore find that the joint mass of Sirius and
his companion is nineteen times as great as the mass of the sun.
The correctness of this result depends mainly upon the accuracy

THE BINARY STARS. 321

of our knowledge on two points : — First, the mean angular dis-
tance of the two bodies apart ; and secondly, the distance at which
they are situated from us. (Their period of revolution it is com-
paratively easy to arrive at by direct observation.) If Sirius is less
than loo billion miles away, then, of course, an angular separation
between him and his couipanion of 7 seconds of arc would not
mean so great an actual distance between the pair as 3388 million
miles. If Sirius is further off than we think, then, of course,
seven seconds of arc separation between the pair would mean a
greater number of miles between them. If, on the other hand,
our measurement of the angular distance is not quite correct, but
is either too great or too small, then the result of our calcula-
tion will be modified accordingly.

There are many other binary stars, the distances of which from
the solar system are approximately known, and which it has there-
fore been possible to weigh in a similar way to Sirius and his com-
panion by careful measurement of the distance of the pair from
each other and observation of their periods of revolution.

The second of the four classes into which I have divided the
double stars — namely, those in which no revolution has been
detected, although the proper motion of the pair through space is
in the same direction and along parallel lines, indicating that most
probably some physical connection exists between them — is not
nearly so interesting as the first class, or binaries proper, and it
has added little to our astronomical knowledge.

To the third class, or merely optical doubles, we are indebted
for our knowledge of the distances at which some of the stars are
situated from us. The apparent shift in the position of the nearer
of the two with regard to the more distant one, when viewed from
opposite sides of the earth's orbit at intervals of six months, being
the basis of the very elaborate and difficult calculations which
have afforded us all the information we at present possess on this
very interesting subject of stellar distances, a description of the
methods by which this is accomplished is beyond the scope of this
paper, and I will therefore pass to the consideration of our fourth
class, or the spectroscopic doubles, which are two stars so close
together in comparison to their distance from us that the spectro-
scope alone is able to divide them. Until the wonderful power

322 THE BINARY STARS.

which the spectroscope possesses of measuring the velocity of the
approach or retreat of a star towards or away from the earth in the
hne of sight was discovered, it had been impossible to detect any
stellar movements except those which were at right angles to our
line of sight, and these only by an elaborate series of most careful
measurements of a star's exact position on the face of the heavens,
made at intervals many years apart ; but the discovery that when
a star is approaching us, all the transverse lines in its spectrum
are shifted slightly nearer the blue end of the coloured band into
which the spectroscope expands the star's light than their position
would otherwise have been, and that if the star is retreating from
us all these lines are moved slighdy out of their proper places in
the opposite direction — namely, towards the red end, at once
opened an altogether new field for research. But the spectroscope
will do more than this : it will not only tell us at once whether a
star is moving towards us or running away from us, quite irrespec-
tive of the star's distance away ; but by measuring the amount by
which all the lines are moved in one direction or the other, and
making a comparison between this amount and the known velocity
of light, it is possible to declare at what speed the star is moving.
I do not propose to deal with the method of procedure by which
these wonderful results are attained, as that is a subject which has
already recently occupied the attention of this (the Leeds Astro-
nomical) Society ; I wish merely to describe some of these results.
We will take Mizar, the centre star of the three forming the
tail of the Great Bear. I have already used this star as an
example of stars of the second class, and until observed spectro-
scopically it did appear with its companion to belong rightly to
this class, as no revolution of the companion round Mizar was
discernible, and both of them, together with Alcor, the small star
near them, appeared to possess proper motion in the same direc-
tion, rendering it probable that some physical connection exists
between all the members of the group ; but Sir Robert Ball, in his
book, Jn the High Heavens, describes the remarkable results which
have been obtained by the application of the spectroscope to
Mizar, the principal star of the group, by Professor Pickering.
Professor Pickering, it seems, has found that Mizar, as well as
being a very easy and beautiful telescopic double belonging to our

THE BINARY STARS. 323

second class, is, when taken by itself, altogether separate from its
companions, found to be a very interesting spectroscopic double,
for when the spectroscope was first applied to Mizar by Professor
Pickering, he found that the lines in its spectrum were sometimes
single and sometimes were all double. When double, one set of
lines had been moved bodily a very little way towards the red end,
whilst the other set had all shifted slightly towards the blue ; they
then closed up again, and then shifted an equal amount in the
opposite direction, thus showing that Mizar by itself, away from
its companion, must really be two stars revolving round a common
centre of gravity, so that at one point in their orbit (which must
be placed almost edgeways to our line of vision) one star would
be moving towards us while the other would be retreating from us,
while when at the opposite points in their orbit the movements of
each star towards or away from us would of course be reversed.
When crossing our line of sight at right angles, the spectroscope
would show no movement at all, and the double set of lines from
the two stars would close up into one set and appear single. As
each set of lines is moved about an equal distance in an opposite
direction, it appears that each of the two components is moving at
about the same speed, which the spectroscope declares to be
approximately fifty miles a second, and it is only necessary to note
the time taken for the lines to open out and close up again twice
to arrive at the length of time occupied in performing one revolu-
tion of the orbit. This is found to be one hundred and four days.

As, therefore, we know the time taken, and also the speed, we
can easily calculate the length of the path travelled, or the cir-
cumference of the orbit round which both the stars are moving,
and its diameter will therefore represent the distance separating
the two stars. This distance between them is found in round
numbers to be about 150 million miles.

The mathematician is now provided with all the necessary data
to enable him to weigh these two companions, and arrive at their
joint mass as compared to the mass of the sun. It is to be
observed that the spectroscope has provided him with all this
information on which to base his calculation, quite regardless of
what the star's distance may be from us. He knows that the
distance separating the components is 150 miUion miles, and he

324 THE BINARY STARS.

knows that their revolution is performed in a hundred and four
days ; he is therefore able to proceed with his calculation in the
same way as I have described in the case of Sirius, and he finds
that the combined masses of the two stars forming the spectro-
scopic double which we call Mizar is no less than forty times as
great as the mass of the sun.

I will now describe one other very wonderful result which has
followed the application of this spectroscopic method of research
to one other star, which, although very different from any I have
before mentioned, must yet be placed in our fourth class among
the spectroscopic binaries. This star is the famous and well-
known variable Algol in the constellation Perseus. Although
beheved to be a binary before the spectroscope was ever applied
to it, yet it seemed impossible that the supposition could ever be
proved, until the spectroscope furnished us with most convincing
evidence of the fact. The remarkable variability in the light of
Algol had attracted attention to it for centuries, as its changes of
lustre are quite perceptible to the unaided eye ; and several
theories accounting for the vagaries of the star have been pro-
pounded. But the one which has commanded most respect, and
which was generally believed by astronomers to be the correct solu-
tion of the mystery attaching to Algol, was one which assumed that
Algol was one of the binary stars having a large dark companion
revolving round him, so that it sometimes passed in front of him
as seen from the earth, thereby cutting off a portion of his light,
or in other words partially eclipsing him ; and it is this theory
which has received such wonderful confirmation from the spectro-
scope. The variability of Algol has been found to be almost
perfectly regular, and the star passes through the complete cycle
of its changes in a period which has been ascertained with great
accuracy to be 2 days 20 hours 48 minutes and 51 seconds. For
a period of 2 days 13^ hours, Algol shines with a steady light as
a star of the second magnitude ; then his brightness begins gradu-
ally to decline, and for 3-| hours he slowly becomes fainter, till he
has lost about three-fifths of his light. At this, the lowest point,
his brightness appears to remain stationary for about twenty
minutes, and then it begins to increase in the same way that it
before diminished, until in 3^ hours from the time of minimum

THE BINARY STARS. 325

Algol has again attained his maximum brilliancy, and this he
retains for another period of 2 days 13^ hours, after which he
goes through exactly the same changes again. The theory of a
partial eclipse by a dark companion was a perfectly feasible one,
but it could not be proved without the spectroscope, as no telescope
would show Algol as a disc of any appreciable size, but merely
(like all the other fixed stars) as a point of light. This could be
seen to vary in brightness, but of course not in shape, as would
be the case if we were near enough to see the passage of a dark
satellite in front, partially eclipsing the star. This we can never
hope to actually see, but the spectroscope enables us to see it with
our mind's eye, and with little less certainty of its truth than if
we saw it in reality.

Professor Vogel first applied the spectroscope to Algol, and he
then found that the star was approaching the earth at a speed of
something like twenty-six miles a second. When next he tried it
he found that Algol was receding from us at about twenty-six miles
a second. He tried again and again, and found that the star was
•really moving with a maximum velocity of twenty-six miles a
second, sometimes towards the earth and sometimes away from
us, and sometimes it appeared to stand still. Vogel found that,
at the conclusion of the period of approach, Algol appeared to
be stationary. Then a slow movement of retreat began, which
gradually increased till a speed of twenty-six miles a second was
attained. Then this gradually declined until he appeared again
to stand still. Then a slow movement of approach began, which
also gradually attained a maximum speed of twenty-six miles a
second, and then slowly decreased until again no movement at
all was perceptible.

Now, it is quite impossible to suppose that Algol can run
along in a straight line with first accelerating and then diminishing
velocity, and stop and turn back at each end of his course. Such
a movement would be quite at variance to all astronomical move-
ments with which we are acquainted, and it is impossible to invent
any system of forces which would produce or explain such an
erratic movement on the part of one of the stars ; yet this is what
the spectroscope at first sight declared Algol to be doing But it
must be borne in mind that the spectroscope cannot show move-

326 THE BINARY STARS.

ments across our line of sight ; and if, therefore, Algol be really
moving at twenty-six miles a second round a nearly circular orbit
placed edgeways to us, this will explain perfectly the appearances
presented, as the spectroscope would only show the movement at
the sides of the orbit, when either approaching us or retreating from
us, and not at all when crossing our line of sight at the nearest
and the most distant points in the orbit. Vogel also found that
the time of this revolution of Algol in an orbit, as shown by the
spectroscope, corresponded exactly with the complete cycle of
variability, namely, 2 days 20 hours 48 minutes and 51 seconds.
It seemed certain, therefore, that a connection must exist between
the orbital revolution and the variability ; and to strengthen this
probability he also found that the minimum always occurred at the
conclusion of Algol's movement of retreat from the earth.

These facts have furnished the mathematician with all the
data he requires for explaining the variability of Algol, and for
finding out a great many things about him. As the time he takes
to complete a revolution of his orbit and also his velocity are both
known, the size of his orbit is at once ascertained. This is found
to be a little more than six million miles in circumference, or, in
round numbers, two million miles in diameter. It is evident,
therefore, that there must be some invisible body of large mass
near to Algol, causing him to revolve in this orbit. The next
point for consideration is the amount of light lost when at mini-
mum, and this is about three-fifths of the whole, the dark body
being only able to cover three-fifths of Algol's surface, so that two-
fifths therefore remain uneclipsed. This minimum lasts for twenty
minutes, and then the star rather suddenly begins to brighten.
The dark satellite must therefore remain wholly in front of Algol
for twenty minutes, aud then begin to pass off The total time
which the two bodies take to pass one another completely must
now be taken into account. This is found, by careful observation,
to be about seven hours and a quarter.

Now if we know the velocity with which each of the globes is
moving, we shall be able to arrive at their respective diameters,
seeing that one eclipses three-fifths of the other's light for twenty
minutes, and they take seven and a quarter hours to pass each
other. The velocity of Algol, the spectroscope tells us, is twenty-

THE BINARY STARS. 327

six miles per second, and, assuming the same density for both the
bodies (which is the only element of doubt in the calculation), it
has been shown that a dark companion of the required size, rela-
tively to Algol, would really have just about half his mass, and
must revolve in an orbit twice as large, or about four million miles
in diameter. The centre of gravity round which both the bodies
revolve must therefore lie at a point between them which is situ-
ated at twice as great a distance from the centre of the smaller
body (the dark companion) as it is from the centre of Algol ; and
as both must revolve round their common centre of gravity in the
same time, it follows that the dark companion, whose orbit is twice
as largQ as Algol's, must travel twice as fast, namely, fifty-two miles
per second.

The orbital velocity of the companion having in this way been
ascertained, and that of Algol declared by the spectroscope to be
twenty-six miles per second, and also knowing that seven and a
quarter hours are required for the two bodies to pass one another,
it has therefore been possible, for the first time in the history of
astronomy, to say, with what must certainly be a very near approach
to the truth, what the size of one at least among the host of stars
is ; and Algol is declared to be just about a million miles in
diameter, or nearly twice as big in bulk as our sun, and his com-
panion about 800,000 miles, or very nearly the same size as the
sun. This is a noteworthy achievement in astronomy. We
have known for many years what the masses of many of the stars
are as explained in the former part of my paper, but no astronomer
has ever before been able to say what the actual size of any star
really is. The stars could, in many cases, be weighed, but it was
impossible to measure them.

As I have said, the only element of doubt in this calculation
is that it assumes the same density for both Algol and his dark
companion. If this is not the case it will, of course, modify the
result somewhat, but this is a matter which it is impossible to
put to the test with the resources at present at the command of
science. Algol's companion is a body which has never been seen,
and I think I may safely say that it never can be seen from our
earth, and it is all the more wonderful therefore that science has
been able to teach us so much about a body which we can never

328 THE BINARY STARS.

hope to see. It is noteworthy also that in all this the distance of
the Algol system from the earth is of no account, and in no way
enters into or affects the calculation.

It has also been possible to weigh Algol and his companion,
and ascertain their masses, in the same way as the masses of other
binary stars have been discovered, and we are assured that though
Algol is about twice as big as the sun (that is to say, has about
twice the sun's bulk), yet he is made of much lighter materials, as
he only weighs about half as much, and the companion, though
about the same size as the sun, only weighs about one fourth of
the sun's weight.

Sir Robert Ball has drawn attention to the (as he terms it)
monstrous proportion which exists between the sizes of Algol and
his companion, and their distances apart, as compared with dimen-
sions and distances in the solar system ; for, whereas Algol is about
a million miles in diameter, and his companion about 800,000
miles, yet they are only about, in round numbers, three million miles
apart from centre to centre • and I will conclude my paper by
borrowing one of Sir Robert Ball's illustrations for you to remem-
ber the relative sizes and distance apart of Algol and his compan-
ion by ; and this is, that if we take a shilling to represent Algol
and a sixpence to illustrate the size of his companion, and place
them so that their rims are two inches apart, they will fairly
represent, with regard to relative sizes and distance apart, the
proportions of this wonderful and interesting Algol system.

Arctic Hail and Thunderstorms. — Mr. H. Harries read a
paper before the Royal Meteorological Society on June 17th, 1896,
on " Arctic Hail and Thunderstorms," in which he showed that
the commonly-accepted opinion that hail and thunderstorms are
almost, if not quite, unknown in the Arctic regions, is incorrect.
He had examined a hundred logs of vessels which had visited the
Arctic regions, and found that out of that number no fewer than
seventy-three showed that hail was experienced at some time or
another. Thunderstorms were not so frequent as hail, but they
have been observed in seven months out of the twelve, the month
of greatest frequency being August. Mr. Harries is of opinion
that the breeding place of thunderstorms in these high latitudes is
in the neighbourhood of Barent's sea. — Science.

[ 329 ]

Xcavci? from in^ flotc^:©ooh :

(3lcaniiui5 from an ^S*l^ Jfie^^— r'W'^'>"'"^A

By Mrs. Alice Bodington.

I HAVE noted down a few out of the many striking instances
given by Darwin as to Bud-variation and Graft-hybrids* in
various plants, showing that the somatic cells are capable of
producing varieties of every kind without the intervention of the
sexual organs.! Darwin also enters at length into the subject of
those sudden variations known to gardeners as " sports." That
these sudden variations are due to some law or laws one cannot
doubt ; yet I think little or nothing is known, even now, about the
mode of action of these laws. Often we recognise a " memory of
cells," by which old and perhaps long-lost ancestral characteristics
are revived ; but quite as often Nature seems to have resolved
upon making a sudden change, as in the case of the yellow
magnum-bonum plum tree, which after forty years produced a
branch bearing purple plums.

. As in the dog, we find a new species descended from the wolf
or the jackal, so in the peach we have a new species descended
from the almond, with what may be called a grandchild in the
shape of the nectarine. The peach is nowhere found wild. It
was introduced into Europe a little before the Christian era, and
from the fact of its not having a pure Sanscrit or Hebrew name, it
is supposed to have originated in Far Eastern Asia, where the
double-flowering Chinese peach still shows transitional qualities.
The fruit of this Chinese peach is much elongated and flattened,
with the flesh both bitter and sweet, but not uneatable. | From

*Animals and Plants under Domestication, Vol. I., Chaps. IX., x., xi., xii.

tChap. xi., p. 398 — " These cases prove that those authors . . . are in
error . . . who attribute all variability to the mere act of sexual union."

TChap. X., p. 359. Van Mons states that he once raised from a peach-
stone a peach having the aspect of a wild tree, with fruit like that of the
almond. The French peach-almond bears a fruit oval and swollen, with the
aspect of a peach, including a hard stone with a fleshy covering, which is
sometimes eatable. A peach-almond grafted on a peach bore during 1863 and
1864 almonds alone ; but in 1865 bore six peaches and no almonds. A double-
flowered almond, after producing almonds during several years, suddenly bore
for two years spherical, fleshy, peach-like fruits, and then reverted to its former
state and produced large almonds.

International Journal of Microscopy and Natural Science.

Third Series. Vol. VI. w

330 LEAVES FROM MY NOTE-BOOK.

this stage, says Darwin, one small step leads us to such inferior
peaches as are occasionally raised from seed.

The late origin of the nectarine, as a " sport " from the peach,
makes its history particularly interesting. Late as is the origin of
the nectarine, it reproduces itself truly by seed, as does the
peach ; and both show an equal tendency to sport. Peter CoUin-
son in 1741 recorded the first case of a peach tree producing a
nectarine, and in 1766 he added two other instances. Mr. Salis-
bury, in 1808, records six cases of peach trees producing necta-
rines ; one of the varieties, the Royal George, had the habit of
producing both kinds of fruit. In short, the evidence is super-
abundant for full-grown peach-trees suddenly producing nectarines
by bud-variation.

Mr. Rivers (p. 361) states that from stones of three varieties of
the peach he raised three varieties of nectarine, and in one of

these cases no nectarme grew near the parent peach tree

Of the converse case — namely, of nectarine stones yielding peach
trees (both free and cling stones), we have six undoubted instances
recorded by Mr. Rivers. Sir J. E. Smith gives the remarkable
case of a tree in Norfolk which usually bore both perfect necta-
rines and perfect peaches, but during two seasons bore " half-and-
half fruit ; " that is, one half a perfect peach and the other a
perfect nectarine.

Darwin sums up the case thus : — " We have excellent evidence
of peach stones producing nectarine trees, and of nectarine stones
producing peach trees ; of the same tree bearing peaches and
nectarines ; of peach trees suddenly bearing nectarines by bud
variation (such nectarines reproducing nectarines by seed), as well
as fruit part nectarine and part peach,''' and lastly of one nectarine
tree, first bearing half-and-half fruit, and subsequently true peaches.
As the peach came into existence before the nectarine, it might
have been expected from the law of reversion that nectarines
would have given birth by bud variation, or by seed to peaches,
oftener than peaches to nectarines, but this is by no means the
case " (p. 362). Can any theory fit such bewildering facts ?

*The "Royal George" peach produced a fruit three-quarters peach and
one-quarter nectarine, quite distinct in appearance as well as in flavour. The
lines of division were longitudinal.

LEAVES FROM MY NOTE-BOOK. 331

That extraordinary monster, the St. Valery apple, must not be
passed over (p. 371) : —

" The flower has a double calyx with ten divisions and fourteen
styles, surmounted by conspicuous oblique stigmas, but is destitute
of stamens or corolla. The fruit is constricted round the middle,
and is formed by five seed-cells, surmounted by nine other cells.
Not being provided with stamens, the fruit requires artificial ferti-
lisation, and the girls of St. Valery annually go to ^ faire ses
pommes,' each marking her own fruit with a ribbon ; and as differ-
ent pollen is used the fruit differs, and we have an instance of the
direct action of foreign pollen on the mother plant." The con-
trast between the -St. Valery apple, with its fourteen seed-cells, and
the pigeon apple, which has only four cells, is certainly very great.
Another odd instance of a "sporting" tendency is given on pp.
348 — 9, where one pea-plant produced four sub-varieties — viz.,
blue and round, blue and wrinkled, white and round, and white
and wrinkled peas ; and though the grower, Mr. Masters, sowed
these four varieties separately during several successive years, each
kind always reproduced all four kinds mixed together.

Sporting in Plums (p. 399). — The grosse mignonne peach at
Montrueil developed a sporting branch, the "grosse mignonne tar-
dive" a most e.xcellent fruit, which ripens a fortnight sooner than
that of the parent tree, and this same peach has produced by bud
variation the early grosse mignonne. By no possible theory, it
seems, can one account for the same tree producing a late and an
early fruiting sport.

A tree of yellow magnum bonum plums, forty years old, pro-
duced a branch which yielded red magnum bonums. A single
tree out of four or five hundred trees of the " Early Prolific "
plum, descended from an old French variety bearing purple fruit,
produced when about ten years old bright yellow plums'.

Chrysanthemum (p. 404). — A seedling, raised by Mr. Salter,
produced by bud variation six distinct sorts, five different in colour
and one in foliage, all of which are now fixed. When a branch of
chrysanthemum sports into a new variety, says Mr. Salter, it can
generally be propagated and kept true.

Rose. — The history of the moss-rose is peculiar ; it is supposed
to have arisen from tlie Provence rose {R. centifolia) by bud

332 LEAVES FROM MY NOTE-BOOK.

variation, for the branches of the common moss-rose tree have
several times been known to produce Provence roses. The
common moss-rose, by bud variation, has produced three varie-
ties. Prof. Casparz has carefully described the case of a six-year-
old white moss-rose which sent up several suckers, one of which
was thorny and produced red fioivers destitute of moss, exactly like
that of the Provence rose ; another shoot bore both kinds of
flowers, and in addition longitudinally striped flowers. This white
moss-rose had been grafted on a Provence rose ; but how curious
is the fact that the influence of the stock lay dormant for six
years !

Sporting Potatoes (p. 410). — A single eye in a tuber of the old
Forty-fold potato, which is a purple variety, was observed to
become white. This eye was cut out and planted separately, and
the kind has since been largely propagated. A whole white tuber
was also produced by this variety of purple potato, and has been
propagated and kept true. Mr. R. Trail stated in 1867 that
several years ago he had cut about sixty blue and white potatoes
into halves through the eyes or buds, and then carefully joined
them, destroying at the same time the other eyes (p. 420). Some
of these united tubers prpduced white and others blue tubers.
Some, however, produced tubers partly white and partly blue, and
the tubers from four or five were regularly mottled with the two
colours. In these latter cases we may conclude, says Darwin, that
a stem had been formed by the union of the bisected buds — that
is, by graft-hybridisation.

Mr. Taylor, who had received several accounts of potatoes
having been grafted by wedge-shaped pieces of one variety inserted
into another, though sceptical on the subject, made twenty-four
experiments, which he described in detail before the Horticultural
Society. He thus raised many new varieties — some like the
graft and some like the stock, others having an intermediate cha-
racter. (Can anything demonstrate more forcibly that the prin-
ciple of heredity and the power of variation are distributed
throughout the somatic cells ?) Several persons witnessed the
digging up of the tubers from these graft-hybrids, and one of them,
Mr. Jameson, a large dealer in potatoes, writes thus : — " They
were such a mixed lot as I have never before or since seen. They

LEAVES FUOM MY NOTE-BOOK. 333

were of all colours and shapes, some very ugly and some very
handsome." Another witness says: — "Some were round, some
kidney, some pink-eyed kidney, piebald and mottled red and
purple, of all shapes and sizes." Some of these varieties have
been found valuable and have been propagated.

Numerous instances are given at great length of the produc-
tion of graft-hybrids, sometimes the tubers being grafted and
sometimes the stems. Mr. Fearing-Burr, a very careful experi-
menter, produced distinctly mottled and most curious potatoes by
inserting eyes from blue or red potatoes into the substance of
white ones, after removing the eyes of the latter. (Letter from
Mr. Merrick, of Boston, U.S.A., to Darwin in 187 1.) In Ger-
many, Herren Reuer and Lindemuth, both attached to the Royal
Gardens of Berlin, inserted eyes of red potatoes into white ones
and vice-versa. Many forms partaking of the characters of the
inserted bud and stock were obtained ; for instance, some of the
tubers were white, with red eyes.

"Characters of all kinds," says Darwin, "are affected by
graft-hybridisation, in whatever way the grafting has been effected.
. . . Herr Magnus asserts with much truth that graft hybrids
resemble in every respect seminal hybrids, including their great
diversity of character. However, the characters of the parent
forms are not often homogeneously blended in graft hybrids. . .
It would seem that the reproductive elements are not so com-
pletely blended by grafting as by sexual generation. . . .
Finally, it must, I think, be admitted that we learn from the fore-
going cases a highly important physiological fact — namely, that the
elements that go to the production of a new being are not 7iecessarily
formed by the fnale and female organs. They are present in the
cellular tissue in such a state that they can unite without the aid
of the sexual organs, and thus give rise to a new bud partaking of
the characters of the two parent forms" (pp. 423 — 4).

I will give two very curious cases of graft hybrids, one being
the Cytisus Adami and the other the famous bizarria orange : —

" The Cytisus Adami is a graft hybrid ; that is, it was pro-
duced from the united cellular tissue of two distinct species. Mr.
Adam, who raised the original plant, procured this variety by
inserting a shield of the bark of C. purpureus into a stock of C.

334 LEAVES FROM MY NOTE-BOOK.

laburnum, and the bud lay dormant, as often happens, for a year.
The shield then produced many buds and shoots, one of which
grew more upright and vigorous, with larger leaves than shoots of
C. purpureus^ and was consequently propagated. Now, it deserves
especial notice that these plants were sold by Mr. Adam as a
variety of C. purpureus before they had flowered, and the account
was published by Poiteau after the plants had flowered, but before
they had exhibited their remarkable tendency to revert into the
two parent species, so that there was no conceivable motive for
falsification. ... If we admit Mr. Adam's account as true,
we must admit the extraordinary fact that two distinct species can
unite by their cellular tissue and subsequently produce a plant, .
. . resembling in every important respect a hybrid formed in
the ordinary way by seminal reproduction" (p. 417).

Throughout Europe, in different soils and under different
climates, branches of the Cytisus Adanii have repeatedly and sud-
denly reverted to the two parent species in their flowers and leaves.
To see mingled on the same tree tufts of dingy red, bright yellow,
and purple flowers, borne on branches having widely different
leaves and manner of growth, is a surprising sight. " I have seen
a single flower," says Darwin, " divided into halves, one side being
bright yellow and the other purple, so that one half of the stan-
dard petal was yellow and of larger size and the other half purple
and smaller." The most remarkable fact about this tree is that in
its intermediate state, even when growing near the parent species,
it is quite sterile ; but when the flowers become pure yellow or
pure purple, they yield seed. . . . Two seedlings reared by
Mr. Herbert from the seed of yellow flowers exhibited a purple
tinge in the stalks of their flowers ; but several seedlings raised by
Darwin resembled in every character the common laburnum, with
the exception that some of the stems had extremely long racemes.
These seedlings were perfectly fertile. That such purity of
character and fertility should be suddenly recognised in so sterile
a form is an astonishing phenomenon. Darwin proceeds to enter
into minute details as to the condition of the ovules and pollen in
the sterile forms.

The famous bizzaria orange offers a strictly parallel case to
that of Cytisus Adavii. The gardener who in 1644 in Florence .

LEAVES FROM MY NOTE-BOOK. 335

raised the tree declared that it was a seedling that had been
grafted, and, after the graft had perished, the stock sprouted and
produced the hizzaria. Gallesis, who carefully examined several
living specimens and compared them with the description given
by the original describer, P. Nato, states that the tree produces at
the same time leaves, flowers, and fruit identical with the bitter
orange and with the citron of Florence ; and likewise compound
fruit, with the two kinds either blended together, both externally
and internally, or segregated in various ways.

I can find nothing as to the way in which the blood-orange is
raised. I have always understood it is produced by grafting the
orange on the pomegranate. If so, it shows the strong influence
which the stock can exercise on a graft, since these oranges are
not only permeated with a deep-red colour, but the flavour is very
much affected.

Vines. — Gartner (p. 419) quotes two separate accounts of
branches of dark- and white-fruited vines which had been united
in various ways, such as being split longitudinally and then joined,
etc. ; and these branches produced distinct bunches of grapes of
the two colours, and other bunches with berries either striped or of
an intermediate new tint. Even the leaves in one case were
variegated. What is particularly curious is that attempts to raise
variegated grapes by fertilising white kinds with pollen of dark
kinds failed.

Bulbs of blue and red hyacinths may also be cut in two, and
they will grow together and throw up a united stem, with flowers
of the two colours on the opposite sides, or in some cases with
the two colours blended together.

"The facts given in this chapter" (chap, xi.), says Darwin,
" prove in how close and remarkable a manner the germ of a fer-
tilised seed and the small cellular mass forming a bud resemble
each other in all their functions— in their power of inheritance,
with occasional reversion, and in their capacity for variation of the
same general nature, in obedience to the same laws. This resem-
blance— or, rather, identity of character — is shown in the most
striking manner by the fact that the cellular tissue of one species
or variety, when budded or grafted on another, may give rise to a
bud having an intermediate character. We have seen that varia-

336 LEAVES FROM MY NOTE-BOOK.

bility does not depend on sexual generation. . . . We have
seen that bud variation is not solely dependent upon reversion or
atavism to long-lost characters, or to those formerly acquired from
a cross, but appear often to be spontaneous. But when we ask
ourselves the cause of any particular variation, we are lost in
doubt." In chap. xii. Darwin goes at great length into the ques-
tion of the capriciousness of the inheritance of variations. For
instance, he mentions some seedlings of a peculiarly coloured
balsam, which all resembled their parent; but of these seedlings
some failed to transmit the new character, whilst others transmitted
it to all their descendants during several successive generations.
The " weeping " or pendulous growth of trees is strongly inherited
in some cases, and without any assignable reason feebly in other
cases. A weeping, or rather a prostrate, yew was found in a
hedge in Shropshire. It was a male, but one branch bore female
flowers and produced berries ; these, being sown, produced seven -
teen trees, all of which inherited the peculiar habit of their parent.
On the other hand, seeds of the weeping beech, sown by Mr.
MacNab, produced only common beeches. Mr. Rivers, at
Darwin's request, raised a number of seedlings from three distinct
varieties of the weeping elm ; . . but none of the young

trees showed the least signs of weeping. Mr. Rivers had sown
above twenty thousand seeds of the weeping ash, and not a single
seedling was in the least pendulous. Other weeping ashes have
faithfully transmitted their characteristic quality, so that the appa-
rent capriciousness of inheritance could not be better exemplified.
I think I have quoted enough on this subject to induce any-
one who is interested in it to examine all the instances given by
Darwin for himself, and if so my object in making these notes
will have been attained.

As Leaves from a Note-book may be allowed to be a little dis-
cursive, I will conclude this paper with some Notes taken from
the Spectator relating to the instincts and habits of birds.

Peculiar Mode of Hatching.
Mr. Edmund Tregear,* writing from Wellington, New Zealand,
says : — " The great penguin of the Antarctic Circle, standing with

*"The Problem of Arctic Life," Spectator, Jan. l8th, 1896.

LEAVES FROM MY NOTE-BOOK. 337

its head as high as a man's waist, hatches its eggs in a very pecu-
liar manner. These are not brooded after the manner of most
birds' eggs. The female lays two eggs. The first she hands over
to the male bird ; the second she keeps. The egg is held on the
upper surface of the large flat feet, and is pushed up under the
waistcoat of thick feathers. It is there held close to the body,
whose warmth gradually vitalises the young bird. So tenacious
are the parent birds of this grip, that if you knock one of them
over it will fall over on its back with its foot stuck stiffly out, still
clutching the egg to its body.

Maintenance of Life in very Low and very High

Latitudes.

With regard to the curious puzzle as to how highly organised
creatures can flourish in very high or very low latitudes, Mr.
Tregear says that between New Zealand and the Antarctic Circle
are numbers of islands, many of which are barren and others
covered with scrub, where tens of thousands of penguins and other
sea-birds make their nurseries. When, during the summer, the
eggs have been hatched and the young reared, the younger gene-
ration is left, and the adults set out for the lands round the South
Pole. They leave in autumn thin and attenuated ; they go for the
winter to the clime of eternal snow and ice ; and they return six
months afterwards as fat as butter to their old haunts. Their
squadrons, swimming in long columns, cover the sea for miles.
When one part of the bird-army strikes its regular nesting-place, it
appears as if word were passed round. The proper inhabitants of
the spot collect and take possession, pushing the youngsters of
last year out to sea. The others wheel their lines to left and
right round the obstacle, and push on northward to their usual
summer homes. It seems that beyond the great belt of ice-cliffs,
which bar the way to the South Pole, there must be pleasant fiords
and bays where the penguins fish and fatten. I neglected to take
notes — except in my memory — of the extraordinary manner in
which Nature provides " cold storage " for bird-life in Siberia. I
believe I can correctly give the main facts. There are at least six
species of birds visiting England in the winter whose nesting-
place is unknown. A gentleman, deeply interested in the subject.

;;:{.s

1. 1'! A VIC! I'ltOM M\ No'l h; I'.OdK

(li'Ici iniiH'd il jkcmIiIc Io (Iimovci IIk- Miiiiinct icsorl ol llicsc
Iniiisilnrv visilorH. His rcsciiK Ik:, led liim .r; l.n :i'. llic 7)///i/nrx

Ol Silii'll.l, wIlK II, Il r, licrillc;,:, Io ■„iy, III lll<- Wllllil 1 1| cm I il ci I llic
vn V ciiiIkh liinciil ni dc, dhil mii. I'liil willi llic \'ciy In:. I niclliii);
ol I lie Miow .III c\l i;i(ilillli;il V ( li;iii|M- i k ( in i ci I, ;iii( I llic liillicilo
Milll.liy VVilHll'S WV\V clilu'cllcil Willi ihc ,liri\';il (il |Imii|;.,iiiiI'. II|)()I1

iIioiis.iihIi; o( iiirds. No ■ iici liail tlicy iili|'lilc(!. ih.in llu-y

ltc).;;ili j'.iccdily Iccdiii).;, :iiid llicii il ;i|i|)c;in'(l lli:il llic •. now li.ul
.u'lrd ii'i M |ii'c'iiTv;i,tivc liii < i miiiIIcss licii ic:.. I''c:ii < >l llic oikoiii
iii|.', ciild cvidciil ly di ivc'. llic hirds soiilli luldic llic hci i ic:, liinc
liliic III ii|>cii III llii' .iiiliiinii, lull illidci llic'.iidw liicy ;iic {icilci lly
|)rc!Hcrvi'd lill llic liiid;, icliiiii III llic nc'iliii]', ',c:imiii. In tin:.
region wcic limiid llic nc:,liii)', |ila((;. (il llncc ol llic :,|jc( ic., whose
iicstiii)-', |il;n (". li.id liccii unknown , llii' oihci linci' soii^lil rt'|j;ions
slili linllici iioilli, .111(1 llicii ncsl;. ;iiid cj'jv. rciii.iin Io he (lis
( ( i\ CI cd.

/'//r Willi lu'i(<l i>l Ih^lhlhUit. 'I'o .ill iho'.cwlio lo\c loiciid
ol, Ol Io w.ili II, llic li;iliil:, ol lixiiij; ;i iiiin;i I:., llic .iiliclc, wlm li
lliivc iip|>r,iicd diiiiii;' llic l;i:.l lew inonllr. in llic S/^crfiltor ;irc :i
|Mc.il dcll;',lil. Soiiicl iiiK :, llic wiilci l.ikc:, ii:. down Io llic ;,lioic,
:iiid wc I .111 III nii.ijMii.il ion lollow lli;il iiilic|iid lolr.lci > .ih lici who
I iiclci :. I he ii.c ol III:. 1 1,1 1 e h.im I;, h i .n ly o| liei iiiodc ol < .il< lini;;
loli',ler, II I, :,ii( > e:.:. Ill :.o |ie(nli,iil\ dilluiill :i l;i;,k r. loiindcd
on llie inlnii.ilc kiiowlcdiM- he h.is .ilLniied ol .ill ihc " hillc w.iys"
ol |oli:,lei;,, which iiKliidc'. ihc loniiinlK liiilul ol lln- in.ilc ,nid
Iciii.ile lolislcrs, w'liii h i',ii h.iiiil in li.iiid ! inc. in ( l.iw in claw Io
hrow.sr n|ion llic :.c:i\vci'tl;, ol iIk (oic;,lioic ( )i \\>- < .in lollow Ihc
coiinoi.inl', oil llic I'.lc ol W'lrlil Icadiii;', .i wilil lilc in ihc d.chiiij;
wave:., \cl oei a:.ioii.illy ( oiidc'.i cndin!', Io loiin .i (in le wliK h ina
(III ill\' diuc; a '.lio.il ol li'.li toward:; Ihc :.lioie, wIk le llie\ ( ,in he
dc\'oilied .il IciMiie .Soiiicl iiik ■, llic ( ( )| iiioi ,inl '. l>e(oiiie eiilai'j'.lcd
111 llic jiai:. ol the l>iio\:. wlin li imi.ikI die Needle;,, and llie\' ( .in
only lu- !(■:,( lied |i\ ,i man a', ln.ue .i:. oiii liKiid the lo!i:,lei
( aleliei , w ho < an diMci'.iid " In ,ik:, I li,il ( nl like :.lie.iis."

I'.iil the .!( (dinil ol the li.ipiM hiid lile ol liolkh.ini I ake and
ollui |iiole(led waU'l'S I', i|iiilc .r. dcli:',lil I ill. The inodilu .it ion:,
ol in',|in( I ,iic \c\\ |ie( iili.ii, \.ii\ini',, ol ( (iiii;.e, a(coidini', to the
|i,ii Ik iil.n '.iiet le:,, l>ul all tendliij', Io ;.liow ill. it the le.n ol liiaii i.s

I.KAVKS IIJd.M MV NOTK-MOOK.

:{;{!)

;iii .It i|iiiic(I insiinci "I'liilci sdihc lolly Irccs on llic ii|iih)mI('
sitii" ol llu- l.ikc," s;ivs llif .mllioi, "were ;i mimlin nl dnk
ohjocls, lioin rij;lity lo ii hiiUilii'ti ; ;mil i)|iinious v.iiictl .1;. lo
whctluT tlu\M' iTiMliut's wcyr shfi|) or dcci l\inf; iisU'cp. I'lu'v
proved lo !>(• a llot L ol ('mikkIm nci'si-. . I'lu" hints ii'mi

larly leave llu- waici al 1 cilaiii hours. .\\\A ll) iiilo ihc mirshrs of
' llolkhani Meals ' helwi'en i\\i- paik ami llu^ sen, wheie llie\ lecil
hy (la\' wilh Ihe laiuoiis wild groy gci'Se ol llolkliam and iiesl like
wiUl hirds in the loiip, hue ol sand lulls lulwieu I lolkliani l!a\ and
NN'ells lliirhoui. A IUNU'iT view ol llie lake showeil llie eiioiuioUS
i\uuiher of iudi^euous wild fowl llu-ie eolleelcd. ihe ed);c' is as
lemihii as ihal ol' ihe I imh', \\ ali 1 in ls.enslu)',lou ( lardeus, aud
the ^rass is eroiiped '.lioil wUh llie ;',ia/iu;', ol ihe |.;ei'se. Aliove
lies tile \^\'cy palaee nl I lolkhaui I lall, aud llie oiilline ol llie waliT
is ns ii'i^ular as di ll ol die llalian window, on die lat^ade ol llu-
lion.e \'el llie lowl he as lliiek as ducks Upon a null pond, lhoU]di
llie I'.nll'. hoveimi; ovei llic aulaee, 01 lloaliiij', like while hoals
aiiiouj^sl the diieks, '.how thai llu:. i:. no home ol hall dome'. I i
I aled hirds, hul die i lioseii lesoil ol lowl lioiii ihe .id|at etil le\ils
ol the sli.illow iioilheiii sea. in loii^li and sloiius we.illi<i,oi
lon^ Irosis, llie line sea ducks visil llii< lake. Hul in mild seasons
only iii.illaid:., wid;;eoii, and leal \ iMl the Like. W hen

disliulied, die whole t omp.ins lose lo iheii leel ,iiid i.in low.uds
the walei, Ihe <hiek .iiiil wid);eou liMiij', Willi .1 iiish and ( lallt 1 ol
wilij^S, and plim;',iii;; iiilo die tcnlie ol the w.ilei, whil .1 llie Mioly
('ools laii till dii'\' leat lied die walei's edj;e, and llieii l.iiiiK lied
ihenisclves m .1 hl.u k lleei aiuou}; llu' f^ay, paili 1 <iloiued (lii< ks.

rhoU|',li so wild aud wary heyoud the hniil:. ol :.,iniluaiy,
ihe hiids are here almost as lame .is those npnii the oiiiaiucnial
watiTS ol the I .oiidon p.nks. They stream oil lioiii the h.nik as
the vi'.itot .ippioai lies, alijditini', mi the w.iha .il a disl.iiK c ol lilly
yards, and I. ike im liutlui nolue ol the iiitiud(i. Ileyoml (he
lake is a k'"^^' "' ''*"'' •""' puic.

Where the ilex^rovc ( nds, a hed ol diied, loii^li i^rass iiinges
the water, through whu h .1 narrow lu aien li.n k, made hy r<iol
passengers and deei, luns to join the mad at lo.ss the d.iui Some
lhi!i|.; U'liK h war, neither grass um hir.hes hlocked this li.u k al die
lime (ll the wiiui's visit, apii.ii eiil ly a dense growth dl le.i.-le lops.

340 LEAVES FROM MY NOTE-BOOK.

A nearer view showed this to be a line of ducks' heads, all turned
in one direction. The birds were standing on the path in a long
line facing the water, the approach of the visitors having given the
signal of " eyes left " to the whole regiment. Some five or six
hundred mallard were soon afloat upon the water, while flight after
flight of widgeon were seen passing over at a great height from
the sea, to join those at the head of the lake.

" Both wild-duck and widgeon leave the lake at night to feed
in the vast stretch of creeks, samphire, salt-marshes, and half-
reclaimed land which lends such strange beauty to the line of
shore between Wells and Blakeney. In their choice of the hour
of departure, these two species, so alike in form and in their habits
when in security, exhibit one of those unexplained differences in
degree of caution in the avoidance of danger, which is one of the
puzzles of the sportsman-naturalist. The wild-duck leave at dusk,
and nightly risk the chance of a shot from the ' gunners ' waiting
on the marshes at flight time. The widgeon wait till dark, and,
except on moonlight nights, seldom lose any of their number to
the gun. As the fowlers are tramping home across the flats, they
hear the widgeon ' like gales of wind ' rushing high over the
marshes ; but the flocks are invisible, except when the moon is for
a moment darkened by ' a misk o' ducks ' flitting across its beams
in the winter sky."'''

These habits of the various species of wild-fowl enable one to
understand how the old hermits in their solitary cells in the wild
fens of Saxon times heard such inexplicable rustlings and move-
ments in the meres; such strange shrieks and wailings in the air,
so that to their excited fancy it seemed that the air and waters
teamed with evil spirits. And that weird flight of the widgeon in
flocks, invisible except when the moon is for a moment darkened
by a " misk o' ducks," gives meaning to the Celtic superstition
that the spirits of the dead could be heard wailing high in air, as
they sought their birthplace beyond the ocean.

* Spectator, Jan. l8th, 1896.

[ 341 ]

niMcromctr^.*

By E. G. Love. Plate XV.

WHOEVER undertakes any serious work with the micro-
scope is confronted, sooner or later, with the necessity
for some method of determining the actual size of
microscopic objects; and it may not be without profit if we briefly
review the different methods for ascertaining this.

As we might naturally suppose, the earliest efforts in micro-
metry consisted in comparing the microscopic object with other
objects whose approximate size was known or could easily be
determined. Thus Leeuwenhoek employed grains of sea-sand
of such size that one hundred of them, placed side by side,
extended one inch. One of the sand grains was so placed that it
could be directly compared with the object under the microscope.
The same idea was adopted by later microscopists who employed
the very small spores of certain plants.

Hooke, as early as 1675, described a method for determining
the magnifying power of a microscope. To use his own words :
" Having rectified the Microscope, to see the desired Object
through it very distinctly ; at the same time that I look upon the
Object through the Glass with one Eye, I look upon other Objects
at the same Distance with my other bare Eye : by which means I
am able, by the Help of a Kuler divided into Inches and small
Parts, and laid on the Pedestal of the Microscope, to cast as it
were the magnified Appearance of the Object upon the Ruler, and
thereby exactly to measure the Diameter it appears of through
the Glass ; which, being compared with the Diameter it appears
of to the naked Eye, will easily afford the Quantity of its being
magnified." While Hooke referred to the determination of the
magnifying power, and that with objects capable of being measured
without the aid of the microscope, the same method is applicable
to ordinary micrometer work.

Dr. James Jurin wound a piece of very fine silver wire about
a pin, leaving no space between the threads, measured any length

* Substance of some remarks made before the New York Microscopical
Society. From the Journal of the New York Microscopical Society.

342 MICROMETRY.

of the coil, and then by counting the number of threads found
the diameter of the wire. This was then cut into small pieces,
and one of them was placed upon or near the object to be mea-
sured, and a comparison made. That this method was very crude
is evidenced by the fact that Jurin found the diameter of a human
blood corpuscle to be i /1940th of an inch.

In 1742, Benjamin Martin described an eye-piece micrometer
which consisted of a screw having fifty threads to the inch. One
end of the screw was pointed, while the other carried a hand
which passed over a dial divided into twenty parts. This appliance
doubtless gave fairly accurate results, and in a more or less modi-
fied form has appeared in later micrometers. Baker also credits
Martin with a glass micrometer having parallel lines i/4oth of an
inch apart, and placed in the focus of the eye-piece.

Geo. Adams, Sr., in his Micrographia, 1746, says that, acting
upon the idea suggested by Jurin, he constructed a micrometer
which consisted of small silver wires stretched in the form of a
lattice, the distances between the wires being equal to the diameter
of the wire, which was probably from the i /500th to the i /600th
of an inch. This lattice was used upon the stage, being placed
under the object if it was transparent and over it if opaque.
Adams, however, appreciated the difficulty of measuring objects
which were less than the diameter of the wire.

Three years prior to Adams' publication. Baker described a
similar arrangement invented by a Dr. Smith, consisting of a lattice
of fine wires or small squares drawn upon glass with a diamond.
This, however, was designed as an aid in drawing microscopic
objects. According to Baker, Cuff devised a micrometer in 1747
which consisted of a lattice of fine wires i/5oth of an inch apart,
set in a circular frame to be placed in the focus of the eye-piece.
This device is shown in Fig. i, PI. XV. Baker made a similar
micrometer of human hairs placed i/ioth of an inch apart. Fig. 2.

Geo. Adams, Jr., in his Essays on the Microscope, describes a
needle micrometer which he states was first made by his father.
This is shown in Fig. 3. It was designed to be clamped to the
tube of the microscope, the needle passing through a small open-
ing in the eye-piece. The screw had fifty threads to the inch,
and was provided with an index moving over a circular plate

MICROMETRY.

343

divided into twenty equal parts, so that each division of the scale
indicated i/ioooth of an inch. The small prism, a, served to
register the number of revolutions. Figs. 3, A, B, and C, show a
sectoral scale used upon the stage to determine the actual value
of the revolutions of the screw. It was two inches long, and
i/ioth of an inch at the base. Hartnack devised a diagonal
scale on the same principle, which consisted of fifty vertical lines
crossed by two horizontal lines, whose distance apart equalled five
divisions of the vertical scale, and which was crossed by a diagonal.
Thus if the length of the vertical line was o'5 inch, the shortest
line^on the lower side of the diagonal would be o'oi inch.

Micrometers may be divided into two general classes : — First,
stage micrometers, in which both object and micrometer are mag-
nified together : second, eye-piece micrometers, in which the scale
is applied to the magnified image of the object. In the latter class
the scale, or micrometer proper, is usually made a part of the eye-
piece, so that the whole becomes a micrometer eye-piece.

Stage Micro meters. — ^These in their crudest form are represented
by the sand grains of Leeuwenhoek, and the silver wires of Jurin.
The micrometers of Coventry were made of glass, metal, ivory,
etc., and bore lines ruled with a diamond at some uniform distance
apart. The use of these micrometers for the direct measurement
of microscopic objects was, of necessity, very limited, being con-
fined to low powers where the object and scale could be brought
practically to the same focus. In other ways, however, these
micrometers are very important. Their use with the camera
lucida and in standardising eye-piece micrometers is familiar to
all microscopists. In the former case any object drawn can be
measured by replacing the object by the micrometer, the conditions
remaining the same. If the size of the object drawn is arrived at
by dividing the size of the image by the magnifying power of the
microscope, the distance from the eye-piece to the surface receiv-
ing the image must be ten inches.

More recently Zeiss has offered a stage screw micrometer,
shown in Fig. 4. This is intended for the accurate measurement
of objects too large for one visual field of the microscope, and can
be adapted to the stage of any of the larger stands. The plan of
this micrometer is sufficiently evident from the illustration. The

344 MICROMETRY.

small dial registers complete revolutions of the screw, the fractional
parts being indicated by graduations on the larger disc, whose
smallest divisions are equivalent to "002 mm. The screw measures
up to 10 mm., or nearly "4 inch.

Micrometer eye-pieces. — These may conveniently be divided into
those with fixed scale and those with movable scale. The eye-
piece may be either positive or negative, the former giving the best
view of the micrometer, and the latter of the object.

In micrometers with fixed scales, the lines may represent frac-
tional parts of a millimeter or of an inch, or, as is usually the case,
be some arbitrary scale, the value of which must be determined
for different combinations of objectives, oculars, and tube length.
The scales ruled on glass in the form of squares, and which are
copied from the lattice micrometers of the older microscopists,
are not to be recommended for general work, although they are
sometimes used in special cases.

In 1840, Geo. Jackson devised an improved form of Martin's
eye-piece micrometer. The scale was on glass and mounted in a
metal frame, with a screw at one end and a spring at the other.
The eye-piece, a negative one, was provided with slits to allow the
scale to be moved across the field. The arrangement is shown in
Figs. 5 and 6, the former being the micrometer, and the latter its
position in the eye-piece.

The method of using this micrometer is familiar to most, but
for the benefit of others it may not be out of place to give one
method, especially as the same applies to other ocular micrometers.
It is first necessary to standardise the eye-piece micrometer. This
is effected by bringing the scale into focus, placing a millimeter or
inch micrometer upon the stage, focussing, and then adjusting the
two scales so that the zero of the eye-piece scale shall exactly cor-
respond with one of the lines of the stage micrometer. Determine
how many divisions of one are equal to an even number of divi-
sions of the other, when a simple calculation will give the value of
each division of the ocular scale in terms of the stage micrometer.
Thus, suppose that 0*5 mm. of the stage micrometer are equivalent
to forty-six divisions in the eye-piece, each division of the latter is
therefore equal to o'oioS; mm. Replacing the stage micrometer
by the object to be measured, it is found that its length is equal to

MICROMETIIV. 345

thirty of these divisions, or in otlier words is o"326 mm. in that
dimension. It is obvious that this vahie for the divisions of the
eye-piece micrometer is good only while the conditions remain
the same.

The form of micrometer eye-piece devised by Jackson has
been largely replaced by one in which the scale, an arbitrary one,
on a circular glass is fixed at the focus of an ordinary negative
eye-piece. The micrometer eye-pieces with movable scales are
represented by the cobweb micrometer invented by Ramsden, and
first used for telescopes. Fig. 7 shows the eye-piece, and Fig. 8
the cobwebs and comb.

It consists of a positive eye-piece, in the focus of which two
fine parallel wires or cobwebs are stretched across the field. One
of these wires is fixed at the centre of the field, while the other
can be moved by means of a screw, having fifty or a hundred
threads to the inch, and whose outer end is attached to a gradu-
ated disc, usually divided into a hundred parts. On the lower
side of the field is a metal comb having notches which correspond
with the threads of the screw. This comb serves to register entire
revolutions of the screw, while fractional parts are indicated by the
disc. It is necessary to ascertain the value of each revolution or
part of a revolution of the screw in the manner already described.
The objection to this micrometer is that the measurement of an
object cannot be made in the centre of the field.

Among other modifications of this micrometer is one by
Nelson, in which the fixed wire was placed five notches from the
centre of the field on the side furthest from the screw head ; and
later the same microscopist still further improved it so that both
wires could be moved en bloc across the field, and also by adopting
a compensating eye-piece.

Zeiss has devised a screw micrometer eye-piece for objects
which occupy a large part of the field. It consists of a Ramsden
eye-piece having a glass-plate with crossed lines, and the whole
can be moved across the field by means of the micrometer screw.
A compensating eye-piece can be employed instead of the Rams-
den for use with apochromatic lenses.

The ease and accuracy of measuring objects by means of
photomicrography is familiar to all who have had experience with

International Journal of Microscopy and Natural Science.

Third Series. Vol. VI. x

346 MICROMETRY.

this method. We believe Dr. Woodward preferred this to all
others for the measurement of blood corpuscles. By substituting
the stage micrometer for the object its image is thrown upon the
ground glass, and then can be measured or photographed as
desired. Measurements should be made upon the negative and
not on the positive print obtained from it.

Regarding the unit of measure to be adopted in micrometry,
it may be said that the micron, or the i/ioooth of a millimeter, is
now generally adopted in scientific work. The standard was pro-
posed by Harting in 1859, who called it a micro-millimeter. This
term was afterwards changed to micron by Listing, and the sign ^
adopted as an abbreviation. The micron is equivalent to nearly
1/25, 000th of an inch. The determination of the magnifying
power of a microscope is effected in much the same way as the
measurement of microscopic objects.

One of the simplest plans is that suggested by Hooke, to
which reference has already been made. If a stage micrometer
is used in place of the object a comparison can be readily made
between the image of any portion of the scale and the ruler placed
at the same distance. Thus if i/iooth of an inch on the stage
micrometer is equivalent to 6/ioths of an inch on the ruler, the
magnification is sixty diameters.

Another simple and accurate method is to use some form of
the camera lucida. The microscope is arranged as for drawing,
the paper being placed ten inches from the eye-piece. It is im-
portant to note that in measuring objects by the camera lucida it
is immaterial what this distance is, since the object bears the same
ratio to the scale at all distances. A micrometer is then placed
upon the stage, and its graduations projected upon the paper and
measured. The magnifying power is found by dividing the dis-
tance measured on the paper by the division of the stage niicro-
meter used. Thus, if i/iooth of an inch of the scale equals three
inches on the paper, then the magnifying power is 300 diameters.

Other methods have been suggested, but they possess no
advantages over those given.

Journal of Microscopy 3™ Ser.VoI 6 Plate 15.

j:— __:^e-^-^ f

'o

THE KEPIIODUCTION OF (nilUTOLlTES. 347

EXPLANATION OF PLATP: XV.

Fig. 1.— Cuff's Wire Micrometer.
2. — Baker's Hair MicroiiicLer.

3.- Adam's Needle Micrometer. A, B, C, the sectional scale.
4. — Zeiss' Stage Micrometer.
5. — Jackson's Eye-piece Micrometer.
6. — Jackson's Micrometer Eye-piece.
7. — Ramsden's Micnuneter Eye-piece.
8. — The scale of the same.

©11 the 1Rcpro^uctiou of iS)rbitoltte9/''

By J. J. Lister, M A.

MR. H. B. Br.\dy has described specimens of Orbitolites
which he obtained in Fiji, showing the margin of the disc
crowded with young shells. Mr. Brady's material was
worked at in the dry state, and it was at his suggestion that the
author collected specimens, preserved in spirit, from the Tonga
reefs. Examination of this material shows that large brood-
chambers are formed at the margin of the disc during the later
stages of growth. These are, at first, lined with a thin layer of
protoplasm At a later stage the central region of the disc is found
to be empty, and the whole of the protoplasm is massed in the
brood-charabers in the form of spores. The spores have the
structure of the " primitive disc," which, during the early stages
of growth of the Orbitolites, occupies the centre of the shells.
They are liberated by absorption of the walls of the brood-
chambers, and each becomes the centre of a new disc, which is
built up by additions of successive ridges of chamberlets at the
margin. The reproduction of Orbitolites, therefore, takes place
by spore formation.

The spore contains a single nucleus, lying in its " primordial
chamber." After several rings of chamberlets have been added,
a stage is reached at which the nucleus appears to be represented
by numbers of irregular, darkly staining masses, scattered through
the protoplasm of the central part of the disc.

In the later stages, numbers of oval nuclei are found in the

protoplasm, often arranged in pairs, and in favourable preparations

they may be seen to be undergoing amitotic division.

* Extracted from the Proceeding's of the Cambridge Philosophical Society
by G. H. Bryan.

[348]

tTecbnoIoo^ of Biatome/

By Mons. J. Tempere.

Conclusion.

The Selection— The Mounting of Isolated Specimens

and Systematic Preparation.

A COLLECTION of Diatoms to be really useful, so that it
may serve as a means for comparing species — their affin-
ities, transformation, etc., etc. — ought to be as much as
possible of isolated, well-marked individuals, so as to be capable
of being classed in a systematic manner.

At first it seems very difficult to be able to take hold of and
transfer microscopic bodies so small as the greater part of the
Diatoms, and yet it can be attained with less effort than might
have been supposed. Certain arrangements, and a little practice
and patience, will suffice, as we shall presently see.

The deposit and gathering, washed and held in suspension in
very pure distilled water, are spread either on microscopic slips or
on cover-glasses that serve to support them. If cover-glasses are
used, I give the preference to those of from 15 to 18 mm. diam-
eter, No. 2, that is to say, rather thick, which when once covered
with Diatoms can be preserved, if they are deemed, suitable, in
little boxes of 17 or 18 mm. diameter, and separated one from
the other by rings of caoutchouc or of card, which can be easily
obtained.

If the spreading be made on micro-slips, which I prefer, they
ought not to exceed from 18 to 20 mm. to the centre ; then these
slips may be placed one on the other, separated by small pieces of
gummed card fixed at the end of each slip.

To conduct the selection under the most favourable condition,
and without risk of confounding the species, it is necessary to use
an optical combination, giving at the same time an enlargement of
from 80 to 100 mm. in diameter, and a focus long enough to allow
the operator free manipulation of the instruments by which he takes
hold and transfers the Diatoms. The longer the focus of the lens,

* Translated from Le Diatoniiste.

TECHNOLOGY OF DIATOMS. 349

the greater the ease of the operator. As to the eye-piece a No. 3
ought to be sufficient, otherwise the eye will be too quickly tired/
the rays reflected from the mirror of the microscope will give
light enough ; an iris diaphragm is useful for moderating the light.
When the light is too intense, I use a piece of clear blue glass
fixed under the stage of the instrument, to soften it still more, the
work of selection being trying to the eyes, especially when it is
continued for many consecutive hours.

In a combination of this kind, there is yet one difficulty to
overcome — namely, the reversal of the image of the object. The
employment of a correcting eye-piece takes away too much light
and definition ; besides, it fatigues the eye more, so I advise our
readers to neglect this, for they will actually become, and that in a
very short time, so accustomed to this optical effect that they will
not notice it, or, at all events, that it will not inconvenience them.

It is the same in the use of the mechanical finger, and of all
other contrivances more or less ingenious intended for picking up
Diatoms. In my opinion, the hand is the only sure instrument,
and in a relatively short time it is possible to acquire sufficient
steadiness. I recommend the use of very simple instruments.
The bristle of a living hog, or of one recently killed, or better still
a hair from the belly of a hedgehog, carefully chosen by means of
a pocket lens, fixed with wax to the end of a light pen-holder,
or held within the jaws of a light drawing-pen, constitutes the
instrument.

I prefer using a drawing-pen to anything else, because then it
is easy to lengthen or shorten the hair according to the require-
ments of the occasion. You can hardly understand, when we have
got a really good bristle, how careful we are of it.

I pass on to notice the little incidents that may happen during
the selection.

The Diatoms jump and pass out of the field of vision on
contact with the bristle.

There are two causes for this : — First, the distilled water has
not been perfectly pure, or possibly the Diatoms have not been
sufficiently washed ; in these cases the valves adhere more or less
to the glass, and the bristle, in suddenly detaching them, makes

350 TECHNOLOGY OF DIATOMS.

them jump in a manner that is not pleasant to the operator.
Second, the bristle has touched the Diatom too much on one side,
and according to its shape has made it take a half-turn, accom-
panied by a jump.

To avoid these, it is necessary, in the first case, to cause the
valve to slide very smoothly before the bristle, sometimes breath-
ing softly on the plate and not lifting the valve till it is free ; and
in the second case, which is the more frequent, only touching the
Diatom on the centre, which is what you always ought to do.

The Diatoms stick to the Bristle.

I have said, in speaking of the choice of a bristle, that it is
needful that it should be taken either from a /iving a.n[ma\ or from
one recently killed. Under these conditions, preserving its natu-
ral fatty condition, it remains supple and the objects adhere to it
more wilhngly. It will be enough to pass the bristle through the
lightly-closed lips to make it sufficiently moist to hold the Dia-
toms, and at the same time to remove any particles of dust that
may be adhering to it. When the valves do not easily leave the
bristle, it is that a little saliva remains on the end of it, or perhaps
that the extremity presents some accidental roughness, in which
case it becomes necessary to change it ; lastly, this tiresome adhe-
rence may equally proceed from a cause that I attribute to an
electric current — a curious fact, but one well known to those who
have selected Diatoms. Mr. Kinker, of Amsterdam, has told me
that when the north wind blew rather strongly, the effect was very
sensible. I have observed the same many times. This is not
always the sole cause ; but each time that an effect of this kind
has been produced, I have laid aside my selection for a more
propitious moment.

When a Diatom has been chosen, it must be transferred to a
slip prepared to receive it, and there fixed. For this it is needful
to use two microscopes, the second serving to centre the slip
carrying the prepared cover-glass ; but then there is some chance
of losing the object en roufe, especially if it be heavy. It is
therefore better to place the two slips side by side on the stage of
the microscope which is used for the selection, and then advancing

TECHNOLOGY OF DIATOMS.

351

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TECHNOLOGY OF DIATOMS.

or withdrawing both together, the desired part of each can be
brought under the objective.

This mode of operation suffices
when you are making preparations
of isolated specimens, but when you
are making systematic preparations,
that is to say, when groups of a
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certam number ot species,
in a certain order, are to be made,
the use of a movable stage is abso-
lutely necessary.

I give a sketch of a stage of this
kind which I have constructed, and
which has done me good service.
In this stage, the height of the box
carrying the hollowed rings for hold-
ing the prepared cover-glasses is so
arranged that the surface of these is
on the same level with that on which
the Diatoms are spread, and this
prevents any change of position,
however long the work may have
to be continued.

Cements used for fixing the
Diatoms on the Cover-glasses.

The liquids or cements used for
fixing the Diatoms are of various
kinds. Some of them change as
they grow older, and lose, if not
totally, at least a part of their adhe-
siveness. Gum-lac is of this class.
In general, the cements present a
dry surface, from which it is possible
to remove dust that may have acci-
dentally fallen on it — such are cer-
tainly preferable to all others.

TECHNOLOGY OF DIATOMS. 353

The composition of those most commonly used is as follows :
Gum-lac Cement.— Dissolve a small quantity of white lac in
alcohol of 90 per cent., making the solution of such strength that
a drop spread on a slip, slightly warmed, leaves a film of lac very
thin and transparent. This solution ought to be filtered after
resting, so that the insoluble and flocculose portions may subside.
As the solution is alcoholic, it spreads spontaneously and evenly
over the slip. It is sufficient to place in the centre a small drop
by means of a small glass pipette ; the only precaution that is
absolutely necessary to be taken, if you wish to get an even and
transparent surface, is slightly to warm the slips before putting the
cement on them.

Gelatine and Fish-Glue Cements.— These two cements are very
good, especially the second ; the preparation is as follows : —
Russian Isinglass, or extra-white Gelatine- i gramme.
Phenique, Distilled Water, as i to 100 - 100 ,,
Acetic Acid (crystallisable) - - - i „
Steep the gelatine or isinglass for an hour or two in the water ;
then dissolve by the application of heat; filter, while hot, through
a simple filter-paper, and then a second time, while still hot,
through a double or triple filter ; then add the acetic acid, the
object of which is to make the solution quite clear and to main-
tain it in a liquid state.

Resinous Cements. — The solutions already described on pp.
268 — 271 can be used with equal success.

For Fixing the Diatoms on the lac, it is necessary to slightly
warm the slips on which they are placed ; for the other three, it
will be enough to breathe softly on them.

For the more convenient preparing of the cover-glasses, I fix
them temporarily on a slip by breathing strongly on it and then
rapidly slipping the cover-glass on this humid surface. Nine times
out of ten the cover-glass adheres sufficiently to allow of its being
perfectly cleaned ; it is covered with the fixing liquid, and the slip
serves to support it while you are placing the objects upon it ;
after which a slight exposure to the flame of a spirit-lamp will
separate the cover-glass from its support.

354

TECHNOLOGY OF DIATOMS.

Cells. — When large Diatoms are to be mounted separately,
especially those with long, fragile appendages, the use of a cell
becomes a necessity. The most simple method is this : — You
prepare a solution of gum arable as thick and as pure as possible.
The water employed to dissolve the gum should previously be
deeply coloured with some aniline dye ; then, by means of a
turn-table, you make on the centre of the cover-glasses already
cemented a little cell from i to li mm. interior diameter, and
about i/io mm. thick, and leave it to dry perfectly. The other
kinds of cells are less useful and more difficult to make, requiring
the use of costly instruments.

Artistic and Systematic Preparations.

These preparations, which certainly are very beautiful when well

done, call for much skill on the part of the operator. The use of

a movable stage then becomes indis-
pensable. To enable you to place
the objects regularly at equal dis-
tances at right angles or in curves,
you use glasses divided into i/io
mm., which are placed in the eye-
piece (Figs. 2 2 and 23). Fig. 23 helps

to make those pretty rosettes, which certainly the greater part of

our readers have admired.

We beg to thank Mons. J. Tempere for the use of the blocks

by which this and the previous paper are illustrated. — Ed.

Fig. 22.

Fi.£?- 23.

Distribution of Fungi by Snails and Toads.— Voglino
communicates a suggestive paper to the Nuovo Giornale Bot. Ital.
(1895, 181), in which he demonstrates that certain fungi {Agari-
cinice) are distributed by snails and toad.s. An examination of the
stomachs of the snails showed the presence of the spores of
various species of fungi which were seen to have begun their ger-
mination, and culture experiments with the excrements of various
snails produced a large number of germinating spores of fungi.
The same was observed on examining the stomachs of toads, in
which the spores of Russula and Lactariiis were specially abun-
dant.— Pharmaceutical Jourtial.

[ 355 ]

®n tbc jfoimation an^ Structure of
Deutal lEuamel/'

Plates XVIIL, XIX, XX, XXL
By T. Lkon Williams, D.D.S. Baltimore, L.D.S, R.CS.I.

ALMOST every anatomist or histologist of note since the
time of John Hunter has made some contribution to the
subject of this paper. In going over the literature of the
theme, one is struck by the wide divergence of opinion expressed
— a divergence which is as marked and emphatic to-day as it was
forty or fifty years, ago. Broadly speaking, all who have written
on the subject may be separated into two groups or schools: those
who have taught that the formation of enamel is effected by direct
cell-calcification, and those who have claimed that the tissue is
produced by a secretion — by the calcification of a cell product.
Between 1850 and i860. Professor Carpenter was maintaining
the former position, and during the same time the late Professor
Huxley wrote several papers antagonising this view, and claiming
that enamel could not be produced by any conversion of a cellular
structure. Curiously enough, his main contention was correct,
although founded upon mistaken premisses. In 1848, the late
Sir John Tomes delivered a course of lectures in which he taught
that enamel formation is the result of the calcification of the
enamel-forming cells. His son, Mr. Charles Tomes, in the last
edition of his work on Dental Anatomy, published in 1894, still
holds to this opinion ; and these views are also shared by Walde-
yer, Wedl, and many others. On the other side, Professor Schafer
in England, Professor Spee in Germany, and Dr. Aijdrews and
Dr. Sudduth in America, have maintained that the enamel cells or
ameloblasts are not directly calcified, but that they are the active
agents in producing the material from which enamel is formed.

It is not my intention to present a summary of the history of
the literature of this subject, and I have mentioned the foregoing
names merely to show that the most eminent teachers have held,

* An abstract of a paper read before the Royal Society, December 12th,
1895. From The Lancet. We beg to thank the editor for kindly lending the
blocks which form the accompanying plates.

356 THE FORMATION AND STRUCTURE

and still hold, widely dififerent views. This difference, I believe,
has largely grown out of relying too closely on one or on a few
particular methods of working. I have seen many illustrations of
the possibility of drawing contradictory conclusions from appear-
ances presented by different methods of treating tissues, each of
these conclusions very probably representing a half truth. Another
reason may also be found in the very great difficulties attending
the preparation of thin sections of developing teeth with all of
the tissues in their normal relations. In deciding, therefore, to
reinvestigate the whole field of the development of the teeth, I
determined at the outset to adopt a large number of methods of
working, in the hope that, by comparing the results of widely
differing treatment, T might unravel some of the tangles in which
the subject has always been involved. I selected for the com-
mencement of my work embryos of the cat, dog, sheep, cow, hog,
and monkey, as well as human embryos of all stages of develop-
ment. The rodents were also represented by mice, rats, and
guinea-pigs. Some of the material was cut while fresh, and some
immediately after fixing by freezing processes. Other material was
fixed and hardened by a great variety of processes, and embedded
in balsam by the Weil process, or decalcified by different acids and
embedded in paraffin and celloidin.

More than thirty different stains and combinations of stains
have been tried, and sections have been mounted in balsam,
Farrant's medium, glycerol, sulpho-carbolate of zinc in glycerol
(my favourite medium for purposes of study), and other preserva-
tives. As there is but little difference of opinion concerning those
earlier stages of tooth development which precede the commence-
ment of the formation of dentine and enamel, we need give no
further attention to this period than is necessary for an introduction
to the subject proper. All students of dental histology are now
aware that the teeth are developed from two distinct tissues. The
so-called enamel organ is a product of the oral epithelium, while
the dentinal germ or papilla is formed in the submucous or dermal
tissues, the former being the first to appear.

The first sections cut for these special studies were from the
jaw of an embryo Iamb at a period just after the commencement
of enamel formation. The material was fixed in a saturated

OF DENTAL ENAMEL. 357

aqueous solution of corrosive sublimate, partially decalcified in a
weak solution of chromic and nitric acids, and embedded in
paraffin. Sections were stained with a modification of the Ehrlich-
Biondi fluid. The appearances were different from anything I had
before seen. There was no trace of a prismatic character in the
partially decalcified enamel, but instead a faint appearance of fibres
running parallel with the inner ends of the ameloblasts, with small
globular masses irregularly distributed among them.

Fibrous Character of Enamel.

With the suggestions which this specimen gave me, I prepared
some extremely thin sections from the persistently growing incisor
of the rat. The enamel rods in the enamel of the rat, as is well
known to those who have studied the subject, terminate a little
below the surface, leaving on the outside a thin layer of clear and
apparently structureless enamel. A partial decalcification of this
layer showed a stroma composed of two sets of fibres running in
nearly opposite directions, neither direction corresponding with
the long axis of the ameloblasts. One set of fibres passes in a
somewhat more oblique course than the other, and becomes con-
fluent with the ends of the enamel prisms. The other set of fibres
sweeps downward on a circular course, crossing the more oblique-
running fibres and the enamel prisms nearly at right angles.
Sometimes both sets of fibres join, and, twisting about each other
in a rope-like design, pass along the course of the enamel prisms
(Fig. i). It is probable that the arrangement of fibres is fairly
constant in teeth of the same animals, although differing widely
in teeth of different animals ; but it is only by cutting sections in
a great variety of directions that one at last gets a true picture of
the complex arrangement of fibres and rods. Enamel from the
teeth of rats and mice shows a more marked fibrous character
than any other that I have examined, and the most striking feature
of arrangement of the fibre is the interlacing or weaving together
of those running in different directions, like warp and woof in a
web. This is very plainly shown in Fig. 2, where the torn edge
of the enamel bears a striking resemblance to the effect produced
by tearing a woven fabric of any sort.

358 THE FORMATION AND STRUCTURE

Structureless Basement Membrane, or Membrana

Pr^.maformativa.
By means of selective stains 1 have been able to demonstrate
the existence of a membrane-like structure lying between the
ameloblasts and the forming enamel, and also between the amelo-
blasts and the stratum intermedium. It is uncertain whether this
structure is identical with the membrana prsemaformativa of
Raschow, Huxley, and others. Its existence has been disputed
by several of the more recent writers upon this subject ; but it is
plainly shown in Figs. 3, 4, 5, 6, and 7. I suggest that the struc-
ture lying between the ameloblasts and the stratum intermedium
be called the outer ameloblastic nmnbrane, while that which sepa-
rates the enamel cells from the forming enamel may be known as
the inner ameloblastic membrane.

The Cells of the Stratum Intermedium.
It has for many years seemed clear to me that the enamel
organ, and more especially the cells of the stratum intermedium,
should be classed among the true secreting tissues. I am not able
to understand how so many good observers have failed to see the
intrinsic plexus of blood vessels, which is very early developed in
this layer of cells. Wedl, Magitot and Legros, Sudduth, and
others say that they have uniformly failed to detect a blood
supply within any part of the enamel organ proper. If we exa-
mine the evolution of this tissue in the enamel organ of the
mouse or the rat, its place among glandular structures at once
becomes evident. All appearance of round, polygonal, or oblong
cells, as usually seen in the stratum intermedium, has entirely
disappeared, and in their place we have a highly differentiated
secreting tissue. The ameloblasts are surmounted by epithelial
papillge, around and between which is a free distribution of capil-
lary loops. The ameloblasts are seen to be in intimate relation
with the papillae, each ameloblast seeming to have a root-like
process which extends into and is lost in the substance of the
papilla to which it belongs. The diameter of each papilla is equal
to about that of five or six ameloblasts, and each papilla may
therefore be said to supply from twenty to twenty-five ameloblasts.
Blood-vessels are seen, in both transverse and longitudinal section,
everywhere about the papillae, and we may often observe branches

OF DENTAL ENAMEL. 359

descending to supply the loops which pass round the ends of the
papillffi lying next the ameloblasts (Fig. 2).

At the commencement of enamel-formation in the teeth of the
mouse there is but little indication of a special secretory organ, as
may be seen by referring to Fig. 4. We see here that the outer
ameloblastic membrane is not structureless, but is apparently com-
posed of very tine fibres.

Method of Formation of Enamel.

Several observers of distinction — notably Dr. R. R. Andrews
and Professor Spee — have described the development of enamel
as a process in which the tissue is formed by the deposit of drop-
lets or spherules of calcoglobuliii. This view is undoubtedly
correct, but, as stated by the writers mentioned, it does not include
all the phenomena that may be observed. The ultimate structure
of completely formed enamel shows that it is built up by the
deposit of bodies which are of very nearly uniform size. There
is, as we shall see, no uniformity in the size of these masses of
calcoglobulin, neither is there anything in their structure which
corresponds with that of formed enamel ; in fact, under the finest
lenses that are made they show as highly refractive masses without
definite structure. Although they are usually more numerous at
the inner ends of the ameloblasts, next to the forming enamel,
they may be seen throughout the entire length of these cells, and
I have often seen them lying close up to the membrane which
separates the ameloblasts from the stratum intermedium. Occa-
sionally I have espied them when they seemed to be actually in,
or emerging from, this membrane. Such appearances are shown
in Fig. 5. It is possible, and I think highly probable, that this
substance, although appearing in the ameloblasts, is really formed
in the more specifically secreting cells of this stratum intermedium.
These masses probably consist of calcoglobulin, an albumin-like
substance holding calcific material in solution. Its function, I
believe, is not the building up of the enamel rods as has hereto-
fore been supposed, but the formation of the interprismatic or
cement substance which binds the enamel rods together.

It is clearly shown in Fig. 6 that the enamel rods are formed
by the superposition or continuous deposition of bodies which are
spherical when they leave the enamel cells, but by compression or

360 FORMATION OF DENTAL ENAMEL.

chemical action are more or less changed into a disc-like shape as
they take their place in the building of the enamel rods. Thus,
for the first time, we have a clear explanation of the varicose
appearance of the rods or prisms in completely-formed enamel.
Each varicosity of the rods represent one of these globules or
disc-like bodies. In the inner portion of enamel next to the
dentine the enamel globules usually melt together so completely
that their individual form is lost, but as we approach the outer
surface of the enamel the rods are clearly seen to be composed of
globular or flattened bodies, not completely united, but still con-
nected by calcified plasmic strings. These plasmic strings, of
which there are many to each enamel rod, are often seen under a
power of from 800 to 1000 diameters to be made up of granules,
and these granules, so far as our present powers of observation are
concerned, constitute the ultimate structure of enamel.

The Cross Stri^ and Retzius Bands.

My observations on these points have led me to totally different
conclusions from those reached by Professor von Ebner of Vienna.
Professor von Ebner regards the striae of the enamel rods as an
artificial appearance produced by the action of acids, and the
Retzius bands as due to ground-off or artificial prism ends, and also
to imprisoned air or gas contained in minute tubes or canals.

I have clearly demonstrated that the cross striae are due to the
varicose enlargements of the enamel rods, and that these varicosi-
ties are produced by the successive deposit of globular masses
from the enamel cells. The deposit of these bodies is simulta-
neously over the entire surface of the forming enamel, hence the
regularity of the lines of striation and increment. I have further
shown that the Retzius bands cannot be due to air or gas in minute
canals, because there are no such canals in normal human enamel.
Neither are these bands due to the ground-off ends of enamel
rods, as may be clearly seen from Fig. 8, where the rods are seen
to pass through several bands without break in their continuity.
The Eetzius bands are caused by pigmentary matter in the granules
which constitute the' ultimate structure of enamel. Completely
formed normal human enamel contains no living matter in the
sense in which this term is generally understood. There are con-
sequently no nutritive changes in enamel after it is once formed.

PLATE XVI[|.

Fig. 1.

Forming enamel from incisor of rat. x 800. a, Enamel cells.
B, Outer fibrous layer of enamel, c, Enamel rods showing twisted fibres.

Il

.y. »« (J

J

Fig. 2.

Forming enamel of rat. x 400. a, Secreting papillte of enamel
organ, b, Enamel cells, c, Torn fibrous edge of enamel.

International Journal of Microscopy and Natural Science.

Third Series. Vol. VI. y

PLATE XIX.

1

I

j
■ I)

- E

I

i

— F

.-■^«g-<to;.;^.^: ...^

Fig. 3.

From longitudinal section of developing tooth of lamb, x 150.
A, Secreting cells of stratum intermedium. b, Outer ameloblastic
membrane, c, Ameloblasts or enamel cells, d, Inner ameloblastic
membrane, e, Enamel, f, Dentine. G, Odontoblasts.

— A

— r.

■: ■•'".jj

— D

- F

Fig. 4.

Section of developing incisor of mouse, x 400. a, Cells of stratum
intermedium, from which secreting papilhe are developed. B, Outer
ameloblastic membrane, c, Ameloblasts. d, Formation of enamel by
deposit of globular bodies from enamel cells, e, Dentine, r, Odontoblasts

PLATE XX.

Fig. 6.

Formation of masses of calcoglobulin in enamel organ of lamb's tooth.
X 800. Stratum intermedium, b, Outer ameloblastic membrane,
c,. Inner ameloblastic membrane. D, Calcoglobulin masses. E, Enamel
globules from which enamel rods are formed, r, Dentine.

'C-

y. liiPRji

-'nut^sufu'

,-^ B
— C

— E

G

Fig. 6.

Section of developing tooth of human embryo. x 600. a, Reticu-
lum of enamel organ, b. Stratum intermedium, c, Outer ameloblastic
membrane, d, Ameloblasts. E,Innerameloblastic membrane, f, Forma-
tion of enamel rods by successive deposit of enamel globules, g, Dentine

PLATE XXI,

Fig. 7.

Section of developing tooth of dog. x 1000. a, Stratum inter-
medium. B, Outer ameloblastic membrane, c, Ameloblasts showing
small masses of calcoglobulin. D, Inner ameloblastic membrane.
E, Enamel.

Fig. 8.

Human enamel. x 1,000. a, b, Bands of Retzius.
rod passing through bands without break of continuity.

c, Enamel

[ m) ]
p^c^aciou^^ c^ iparaeitic lEncmiee of Bpbi^c6

(incluMno a Stu&\? of ir^i^pev^parasitcs).

By H. C. a. Vine.

Part IV. (concluded) and Part V.

Plates XIII. (July Part) and XVII.

"\T 7'HEN completing the drawings for the last part of the
V V section on Heteroptcra, some observations led me to
think it probable, and indeed almost certain, that another
group of this sub-order includes aphis-eating species, and I inclu-
ded, therefore, in PL XIII., a drawing of the only European
species, the Podisus liiridns of Fabricius. This insect is one
of the family, Pentatomidce, and in common with other species of
that group, in the larval form, has four joints only in the antenna,
while the perfect insect possesses five joints in these organs.

The majority of the species of this family are inhabitants of
the United States, where the favourable surroundings have caused
a development of the Hemiptera much beyond any that obtains
in Europe, and it was an account given by Professor Eiley of the
attacks of several species, and in particular P. sphwsa, upon the
larva of the Colorado Beetle {Doryphora lo-lineata, Say), which
led me to suspect that some varieties of the family would prove to
be aphidivorous. I have since observed that in captivity the
species figured will occasionally destroy small, soft insects, and
among others aphides, and in view of these facts it may prove of
interest to include here some account of the one European species
and of the best known of the American varieties.

The former — Podisus luridus, Fabr. — is figured on PI. XIII. at
Fig. 1 1, and it bears a strong resemblance to the genus Tropicor/ns,
from which the mature insect may be distinguished by its much
shorter and stouter rostrum, and in general by the comparative
shortness of the antennae. The colour of the mature insect is
dull yellow, ochreous, to brownish, showing a considerable amount
of green opalescence or reflection, which becomes the prevailing
colour of the head. The margins of the thorax are distinctly
green, while the yellowish scutellum is pretty closely punctured

870 PREDACIOUS AND PARASITIC

with dark depressions, generally green also. The elytra, thorax,
and head are all thickly and deeply punctured in a manner which
frequently gives a mottled appearance to specimens. The mem-
branous portion of the hemelytra is smoky, and the whole effect
of the colouring is somewhat dull, unless in an oblique light, when
the green and purple iridescence overcomes the duller lines.

The tarsi are black, the legs yellowish brown with dark blotch-
ing, and the tibi« of the anterior pair are spiny. The posterior
edges of the thorax are produced laterally in a very remarkable
way.

The American variety of this genus, which I have mentioned
as probably — in fact, pretty certainly — aphidivorous is described
by Professor Riley as Arma spinosa, Dallos, and is known in the
United States, which is its chief habitat, as the ' Spined Soldier-
Bug.' It, however, belongs to the modern genus, Fodisus, and —
although, so far as I am aware, it is not found outside America —
the possibilities of transit are so great that it is pretty certain to
be sooner or later found on this side of the Atlantic, and in this
event will doubtless make Aphides one of its chief sources of
sustenance.

Professor Riley, who has made special study of the natural
enemies of the Colorado Beetle, gives the following particulars
concerning this species : — " This is one of the most common and
efficient of Doryphora's enemies, occurring in all parts of the
country, and seeming to have a decided fondness for our potato-
destroyer, especially for the soft larva. It is of an ochre yellow
colour. Thrusting forward his long and stout beak, he sticks it
into his victim, and in a short time pumps out all the juices of its
body and throws away the empty skin. He belongs to a rather
extensive group {Scutellera family) of the true bugs [Heteroptera),
distinguishable from all others by the very large scutel, which in
this genus is triangular and covers nearly half the back.

" The Spined Soldier-Bug may be at once distinguished from
all allied bugs, whether plant feeders or cannibals, by the opaque
brown streak at the transparent and glassy tip of its wing-cases.
The eggs of this Soldier-Bug are pretty little, bronze-coloured,
cauldron-shaped objects, with a convex lid, around which ciliate
fifteen or sixteen white spines. They are neatly placed side by

ENEMIES OF APITIDES, 371

side in clusters of a dozen or more upon leaves and other objects,
and are so much subject to the attacks of a minute Hymcnopter-
ous parasite, that those who undertake to hatch such as are found
outdoors, will more often get flies than bugs. The newly-hatched
bug is ovoid and shiny black, with some bright crimson about the
abdomen. In the full-grown larva the black still predominates on
the thorax, but some four yellowish spots appear, and the abdomen
becomes more yellowish, though still tinted with red. In the
pupa, which is readily distinguished by the little wing-pads, the
ochreous-yellow extends still more, and finally, with the last moult,
the black disappears entirely in the perfect insect. Throughout
the miniature stages the shoulders are rounded, not pointed, and
the antennae have but four joints instead of five, as in the mature
bug, while there are but two visible joints to the feet, or tarsi,
instead of three. . . . The Spined Soldier-Bug by no means
confines himself to the Potato-Beetle larvae, but attacks a great
number of other insects."

It appears to me probable that another species which Professor
Riley has described as the ' Bordered Soldier-Bug,' also very des-
tructive to the larvae of the Colorado beetle, is probably identical
with the species of Fodistis, which has been already described in
these pages.

Part V. Plate XVII.

Travelling beyond the borders of the class Insecta, we find
some occasional destroyers of Aphides among the voracious divi-
sion of the Arachnida or Spiders, the distinguishing mark of
which is the absence of the definite division into three sections :
head, thorax, and abdomen, which characterises the former class.

The voracious and carnivorous habits of the group are well
known, some species not only devouring other insects, but also
those of their own kind, and Col. L. Blathwayt states that in some
varieties the females promptly thus dispose of the more diminutive
males when their services are no longer required for the propaga-
tion of the species. This (to us) unnatural instinct accords well
with the popular belief in the ferocity of these creatures, and the
danger consequent on the attack and bite of certain of the larger

372 PREDACIOUS AND PARASITIC

species, and although the researches of naturalists have gone far
to clear away the exaggerated conceptions which formerly prevailed
as to the destructive properties of the Arachnida, there can be no
doubt that to the largest insects, and possibly to some of the
smaller mammalia, the bite of some species may prove fatal, while
the annoyance which some of the most minute species is able to
inflict upon men, is exemplified in the irritation following the bite
of the ' Harvest Bug,' one of the family Tro?nbidiidce, or ' Spinning
Mites,' to which the aphis-sucking species also belongs.

This family, which belongs to the order Acarina, differs from
the typical Arachnid in wanting the division into head and abdo-
men, which is so marked a feature of the latter. In the Trom-
bidmm the parts answering to the head, thorax, and abdomen are
united to form an irregularly-shaped oblong or ovoid mass, covered
in the mature state with dense, short hairs or bristles of even
length, and sometimes knobbed at the terminations, as in holoscri-
ceum, or pinnate, as in some other species.

The family comprises a considerable number of species and is
very widely distributed, and so nearly do many of the species
resemble the species of the nearly related Hydrachnidce, that
figures of these may be readily mistaken for those of TroitibidiidcE.
The Troinbidiuni in its earlier stage ( = larva), is an active six-
legged mite, more or less hirsute, but generally only to the extent
of stiff bristles, rather sparsely scattered over the body and legs.
The mature Trombidium is possessed of eight limbs, and has
generally lost the ovoid form which characterises many species in
the earlier stage. Four eyes are observable on the anterior surface
of the body in Ho/osericeum, and in other species they may with
some difficulty be made out, but not often very readily.

The chelicerte are armed with two minute, needle-like appen-
dages, or with a pair of delicate claws, usually much thinner than
the claws of the legs, and they bear also at the extremity a knob-
like bristle, or a brush-hke appendage, the precise purpose of
which it is difficult to recognise. The chelicerse of the most nearly
allied families of the Acarina are provided with opposing claws or
nippers, recalling those of the crab.

The palpi are terminated by, a horny point and a thumb-like
process, which is attached below the point by a delicate hinge,

ENEMIES OF APHIDES. 373

and appears capable of being opposed to the latter. In Holoscri-
ceum this process is so clothed with stiff bristles as to assume
somewhat of a hard character, while in other species a rounded,
fleshy structure obtains.

Some varieties are known to be vegetable feeders, and are
believed to do considerable damage to plants and trees, to the
under surface of the leaves of which they usually attach them-
selves and suck the sap much as do the aphides. But Tetranychus
telarius, Trovibidiion Holosericeum, and other species prefer either
a mixed or a wholly animal diet, and as the vegetation which they
frequent is also the habitat of some of the most prolific species of
aphides, the juicy insects afford a convenient and, we may pre-
sume, a palatable nutriment. For with the opportunity the meal
is repeated, and in the presence of plenty the Aphis-eating habit
has become established.

These Arachnida during their early stages are frequently para-
sitic on some more bulky host either of the insecta or of their own
class. Thus, T. Holosericeum frequently passes its larval period on
the body of the slender Harvest Spider, where it attaches itself to
the under surface of the abdomen, or thorax, and may be ob-
served as a scarlet spot, which becomes more prominent as the
mite grows in size, and where it at length quits its protecting,
though possibly not unwilling, host. It finds in the soil a retreat,
where a period of rest analogous to the pupal stage of insects is
passed. Two or three weeks suffice for the change, and the
minute ovoid nymph produces an eight-limbed mite, which be
comes in turn the parent of a new generation.

I have observed the young of a very minute species which I
have been unable satisfactorily to identify thus parasitic upon the
large black aphis of the poppy, and I cannot avoid the conclusion
that, in this case (and probably in the former one), the larva draws
its nutriment from the host to which it is attached. It is stated
that some species undergo their transformation without quitting
their host, but I have myself not been able to confirm this.

The identification of the different species of these curious
creatures presents some difficulties, but I have been able to satisfy
myself that Tetranychus te/arius, Linn., Trombidhini Holosericeum,
Tetranychus tiliarum, Miiller, and a robust specimen covered with

374 PREDACIOUS AND PARASITIC

pennate hairs, not identified, are actually aphis destroyers ; while
I have no doubt that several other closely-related species, which
I have been unable to determine, probably have the same habit.
But it should be observed that the total destruction of aphides
thus effected is comparatively small, and that in all probability
the injury inflicted on vegetation far outweighs the service render,
ed to man by these minute creatures.

The habit of these mites is to spin a slight fine web on the
under surface of the leaves of the vegetation which they haunt,
and under this protection the plant-feeders draw their nourishment
from the host, while the carnivorous mites go out to find food, and
both dispose, between the filaments of the web, the eggs which
are to continue the species. These eggs are shown on Plate XVII.,
Fig. 8. The most striking feature of the mature mites is the
curious capitate, or plumose, bristles with which they are closely
covered. So densely are they placed, that in T. holosericeum a fine
velvety appearance is produced, resembling a close, short fur. The
plumose bristles which cover some of the most determined aphis-
eaters, seem to consist of several short, tapering joints, from each
of which some fine hairs diverge obliquely. The character of the
slender double claws and the capitate hairs, and brush-like pads,
which are their general appurtenances throughout the family, are
of great interest ; and the small, brilliant, circular eyes may be
observed among the bristles along the front of the mite and im
mediately above the opening of the mouth. The chelicer^e do
not terminate in nippers, and the colour, which is usually of a
more or less brilliant red, is sometimes spotted with dark brown.

The position of the Family Trombidiidcc, in the Class Arach-
NiDA, may be seen by the following tabulation : —

Class Arachnida.
Orders. — Arfhrogastra, Arancida, Acarma, Tardigrada, Lin-
guatulina, Paiitopoda.

The Acarina are divided into seven families, distinguished
as follows : —
I. — Forepart of head prolonged into a distinct beak
and separated by a constriction from the rest of
the body ... ... ... ... Bdellidcz

Journal o( Microscopy S"^--*^ SerVol 6, Pla±e 17.

? '/ 1 ^

/V.C^.A yine, aainut ct£i.

Aphidivorou.s Aca.ri7T.-a.&.

ENEMIES OF APHIDES. 375

II. — Fore part of head not ])rolonged into a distinct
beak.

A. — Skin firm.

1. Skin scarcely extensible, palpi not seated on
a common chin piece.

(a) Chelicerffi, claw or needle like; Palpi
terminated by pair nippers ... Trombidiidce
Palpi, with bristles or hook at end ... HydracJmidce

(b) Chelicerae, with nippers ; first joint of

Palpi very large ... ... OribatidcE

Joints of Palpi nearly equal ... Cramasidce

2. Skin leathery, very extensible \ Palpi attach-
ed to a chin plate ... ... ... Ixodidce

B. — Skin soft, with few chitinous bands ... ... Acaridce

EXPLANATION OF PLATE XVII.

Fig. 1. — Acarus (species ?) attacking Aphis on apple leaf (from a
mounted specimen shewing both in natural positions).

,, 2. — Larva of a Trombidium, with Poppy Aphis on leaf. This
larva was apparently parasitic of the aphis.

,, 3. — Leg of larva in last figure.

,, 4. — Palpi and mouth parts of Trombidium holosericeuni.

,, 5. — Leg and claw of last.

,, 6. — Acarus (species?), taken by Mr. Watkins, attacking Aphides.

,, 7. — Claw of last.

,, 8. — Eggs and web (after Miss Omerod).

,, 9. — Tetranychn^ telarius, Linn, (after Miss Omerod).

According to Meehan's Afonthly, the large majority of plants
are scentless, and probably not one-tenth of the hundred thousand
flowering plants known to botanists are odorous. Of the fifty
known species of the mignonette family, only the one so highly
prized in our gardens is fragrant, and only about a dozen of the
one hundred species of violet are scented. In many large genera
the scentless varieties are as one hundred to one, and sweet-smell-
ing varieties are comparatively rare among our wild flowers.

[ 376 ]

Ibalt^'lbours at tbe flDicroscopc witb tbe
late flDr. Znttcn meet

Plates XXII., XXIII., XXIV.

Arborescent Crystallised Silver (Plate XXII., Fig. i). — I'hisis
truly a lovely slide ; when viewed as an opaque object with the
light well directed, it is strikingly beautiful, and will tem[)t many
of us to try, by repeating the mounter's experiment, to get its
counterpart for our own collection. I have never seen any so
perfect of its kind as this is. Its wonderful resemblance in minia-
ture to vegetable growth is well seen by comparing it with the
algae, Angiunaria dilatata, happily present in the same box as if
for the purpose of comparison. The juxtaposition of the pair
suggests thoughts like these : — In each case we have a substance
in solution, to begin with —the one a mineral salt, the other vege-
table protoplasm. The essential correspondence in the angle
assumed by the branches with regard to the main stems indicates
that the deposits i?iust have been laid in obedience to the same
fundamental view, magnetic currents being doubtless the imme-
diate agents, copper having a stronger affinity for some nitric acid
wedded to silver, robs the latter and sets free the Dian metal. In
the second case, by the play of affinities less easy to comprehend
in their entirety, a corresponding force separates what we see here,
and lays it down as vegetable growth, on a well-recognised plan,
which bears its appropriate name : the " formed material," in one,
Pure Silver ; in the other, an "alga." The idea might be extended
so as to embrace the Animal Kingdom, in which some of the
Sertularian Zoophytes probably show the nearest approach to
deposition on the like plan.

Spines of Spatangus (PI. XXII., Figs. 2, 3, 4, 5, 6).^ — " Spa-
tangus " is one of the " Heart Urchins." By careful consideration
of this specimen, and comparing it with an entire example, we
learn that the piece of shell with its attached spines, here shown,
has been taken from the right side near the position of the vent.
Study of the figures on the Plate, with their explanation, will, I

HALF-HOURS AT THE MICROSCOPE. 377

think, render it unnecessary to say much more about it in these
notes.

There are few microscopic objects more instructive or beautiful
than these, especially when bleached. An amount of variety will
be found in the form, size, and direction of the spines on one of
these shells, which will afford much room for thoughtful reflection.
The function of those before us appears to be primarily that of
defence ; on either side of the median line, proceeding backwards
from the mouth, is a set, the components of which resemble tiny
ivory spoons. I expect these are to aid the creature in burrowing
into the sandy tracts in which it resides. Interspersed among the
latter are some straight and very slender ones, whose function I
take to be probably that of tactile organs, analogous to the
" Vibrissas " of higher animals. The spine-like scales of some
insects have a considerable general resemblance to the spines of
Spatangus ; this is well shown in the wing of the larger Midge,

I do not know if there be sufficient difference in the spines of
Spatangi to enable us to discriminate species thereby. The one I
am most familiar with, and the commonest, is S. purpureus.

Anguinaria dilatata (PI. XXII., Figs. 7, 8, 9). — There are two
well-marked species in this genus which are confounded together
by Dr. Johnston {Brit. Zooph., I., 290, and PI. L., Figs. 7 and 8).
These species are A. anguina., the common form, and the present
one, which is sometimes called A. spatulata. Prof. Busk has, with
his usual minute accuracy, described the anatomy of A. anguina
in an old volume of Trans, of the Microscopical Society of London.
The resemblance in this species to a snake is very striking ; the
tentacles, when partially protruded, simulating a many-forked
tongue. At the aperture of the mouth is a horny lower jaw,
horse-shoe shaped in its figure. Mr. Busk described and figured
the muscles which open and close this jaw ; they are attached to
its angle, and consist of a small abductor of two fibres, and a
larger adductor, fan-like in shape, on either side of the mouth.
The fibres composing these muscles are of the striped kind, indi-
cating the possession of will in the creature having them. The
long muscle, whereby the polype is withdrawn into its cell, is
peculiar, in that the fibres composing it are permanently separate ;

International Journal of Microscopy and Natural Science.
Third Series. Vol. VI. z

378 HALF-HOURS AT THE MICROSCOPE.

that is, they are not united together to form a mass.

A nervous system has been described in some of these Polyzoa.
I am not aware that the observations have yet been confirmed ;
still, the rapidity and consentaneity of their actions seem to render
its presence almost (as we might say) a matter of certainty. The
polypidom is described by Mr. Busk as subject to a curious acci-
dent : the falling off, namely, of the upper part - a fresh portion,
or " head," being, however, formed. A " callus," or thickened
scar, marks the place of union and reproduction. The specimen
before us appears distinctly to show marks of similar fracture and
repair.

Eggs of Parasite of Common Fowl (PI. XXIII., Figs, i, 2, 3). —
It is rather misleading to call this as above, as it appears to imply
that there is only one parasite of that bird. There are, however,
no less than four species of lice, belonging to as many genera, to
which domestic fowls act the part of hosts. These are :—

1, Goniodes dissimilis. 3, Lipetirus variabilis.

2. Goniocotes hologaster. \.,' Menopon pallidum.

Now, can we find out to which these belong ?

Eggs, believed to be from Menopofi pallidum, the commonest
of the four, may be briefly characterised as " upwards of three
times as long as broad, scarcely visibly punctate."

Such of the Lipeuris as I know are still longer in proportion to
their width and smooth. That leaves the maternity of these pro-
ductions to be settled between the two Gls in the above list : the
Goniodes and the Goniocotes. Does either genus possess species
habiting, the one the pigeon, the other the fowl? Such is the
case with Goniocotes I I think the probability is that these are the
eggs of Goniocotes hologaster.

Such furnishes a good illustration of the slow and patient
process by which that accurate knowledge of things to which the
term " Science " is applied has to be gained, and may serve as
some justification of the annoyance felt by scientific men when,
from the want of care, or (in some cases) a direct intention to
mislead, barriers are erected to their progress, which at times prove
very difficult to clear away. It is deeply to be regretted that
H. Denny did not live to publish his intended work on the Eggs

HALF-HOURS AT THE MICROSCOPE. 379

of the A7iopliira, for which he had collected the material. These
are now, I believe, at the British Museum, and may be studied by
those who will take the needful steps to procure access to them.

Fly (PI. XXIII., Fig. 4). — The form of the antennae; the vena-
tion of the wings, in so far as can be made out ; the general
aspect of the legs and their appendages (hooks, flaps, etc.), all
proclaim this to be a species of Scatophaga. It furnishes a good
opportunity for saying a few words on the parts composing the
body of an insect. There are, then (with comparatively few
exceptions), thirteen segments in all insects. These may be thus
enumerated : —

I. — Head (composed of 5 sub-segments).

2, 3, 4. — Thorax.

5 — 13. — Abdomen; the first six segments containing the
organs specially devoted to the reception and digestion of food ;
the remainder modified in various ways in connection with the
genital organs. Two segments only of the thorax have spiracles,
the first and the last. The former of these is what is sold by
object-vendors for " Spiracle of Fly," and is the one commonly
figured. It is curious to find that the male fly has one pair of
spiracles more thnn the female, indicating greater development of
the respiratory function for flight in search of her. A correlated
fact is that the compound eyes with him occupy a much greater
extent of surface, in some instances all but covering the crown of
the head. The peculiar hooks terminating the abdomen of the
male Scatophaga are here well shown.

The males of some flies feed upon pollen and nectar, whilst
their partners prefer gross decaying substances.

Hairs of Tiger-Moth Caterpillar (PI. XXIII., Fig. 5).— The
introduction of this specimen to our boxes must be regarded as
an important fact, for the necessity of making ourselves thoroughly
acquainted with the structure of the common objects around us
comes to my mind with continually increasing force.

The caterpillars of the Bombycidce (to one of which those
before us belong), many of them possess hairs capable of pro-
ducing urtication to a greater or less degree. It is not yet quite
settled to what this is due. Those, however, who are in the habit

380 HALF-HOURS AT THE MICROSCOPE.

of handling Cacti, and know how their spines get into the skin
and rankle there, will not, I think, find it difficult to refer the urti-
cation of caterpillars' hairs to the same merely mechanical cause.
A paper on this subject was published in the Monthly Jourti.
Micro. Soc. for October, 1874; but it leaves much to be desired,
both in the description and the figures. Some foreign caterpillars
sting much worse than any we have — r\o\.2^i\y Bombyx processiofiea,
on which, with much of an entertaining description, consult
Kucheumeister's Manual of Parasites, Sydenham Soc. Trans.

Scales from Wing of Clothes-Moth, Tinea vestianella, PI.
XXIII., Fig. 6). — It is satisfactory to see this slide for reasons
similar to those assigned in the last case. The long hair-like
scales fringe the hinder margins of the wings. I believe very
little has up to the present time been done towards classifying
scales according to their form; referring these forms to their
proper places on the wings, etc., and explaining their uses. Here
is a wide field open for many workers. The older observers con-
tented themselves with figuring as many varieties as possible — an
endless task where, amongst tens of thousands, no two occur
exactly alike. There are those who have attempted their system-
atic study ; some have given it up in despair, failing to find any
clue through the labyrinth of forms; others have abandoned it
from lack of time, or the funds necessary to its successful pursuit.
And yet I think there is a clue, and one which is less difficult to
find than is commonly supposed. If the feathers of a bird were
plucked, a handful of them taken and thrown down indiscrimin-
ately, the keenest observer would be unable to refer each to its
proper place ; and again, " No two would be found exactly alike."
But by studying the feathers carefully and minutely on the skin, a
reasonable approach to accuracy may be gained ; their forms and
their uses defined. Bear this in mind as the leading idea required
for successful study of Lepidopterous scales, and I am persuaded
results far surpassing any yet recorded will be gained. As the
result of many careful observations, I am of the belief that (in
most of the Lepidoptera at any rate) peculiar scales are present,
whereby the species yielding them may be characterised. In the
Picridce, and some other genera of Butterflies, the males alone

HALF-HOURS AT THE MICROSCOPE. 381

have remarkable scales not found in the other sex. Those from
Garden-Whites and Meadow-Browns are commonly known and
figured. John Watson, of Manchester, has done most hitherto
towards advancing our knowledge on this subject. His observa-
tions, so far as published, are to be found in Tratisaciions of the
Literary and Philosophical Society of Matichester.

Beetle from Butterfly Cabinet (PI. XXIV., Figs. 1—7.)— This
is Dermestes lardarius, the Bacon beetle, the type of the Dermesiidce.
I have preferred representing her ladyship from a living specimen.
You will thereby be better able to recognise her if she come under
your notice. The head, thorax, and hinder half of the elytra are
pitchy black ; over the upper part of her body (and not only when
she goes to courts but in every-day life also) she wears a beautiful
fur cloak, elegantly " Vandyked " below, with three spots of a rich
purple colour on each shoulder. Her otfspring is very destructive
to furs, stuffed specimens, the contents of entomological cabinets,
etc. As to how her ladyship got to where she was found, she
might say with Topsy, " I guess I growed there " ! The form of
the ovipositor leaves little difficulty in settling that point. Her
mamma (guided by an acute sense of smell) doubtless inserted
her tool as far as she could at some part where the two halves of
the box join, then dropped an egg. The little rascal hatched from
it, lively and slippery as an eel (having long, polished, backward-
pointing hairs all over), soon wriggled its way in, then revelled for
a twelvemonth at least on the choice treasures in our friend's
cabinet. It then, after moulting several times, at each operation
growing much bigger, in due course of nature went to sleep for a
time in its last larval skin, through which the perfect beetle burst
on arriving at maturity. Westwood has some most interesting
notes on this genus {Mod. Class, of Insects, I., 155 — 161), to
which reference must be made for further information.

Skin of Carder Fish (PI. XXIV., Figs. 8— 12).— I have spent
some time in trying to ascertain the scientific name of this fish,
but without success. The scales differ somewhat in form from
those of the Lesser Spotted Dog-Fish, Scyllium caniculiim ; still
more in the closeness with which they are set on the skin. Still,

382 HALF-HOURS AT THE MICROSCOPE.

the differences do not seem to me greater than may be explained
by supposing the pieces of skin to have come from different parts
of fish of the same kind. It is of essential importance, in feeling
our way to exact knowledge, that every step should be made sure.
I wish very much to see longitudinal and transverse sections of
these scales, with the skin in which they are implanted, as well as
thin sections made parallel with the plane of the tooth-like
portion. This will bring out some very interesting points and
show how marvellously like teeth they are, both in conformation
and in structure. The fish drawn on this Plate (with the hope of
ascertaining if it be of the same species with that from which the
scales were taken) was a great favourite with me when on a visit
to the Boulogne Aquarium. It lay on a ledge of rock, absolutely
without motion, all the time its portrait was being taken, and was
a very handsome fellow, but with '■'■such a wicked eye" like you see
in the portraits of Napoleon Trois. What looks like a projecting
tusk is but a fold of skin which hangs down on either side of the
mouth — a sort of feeler, in fact. These fish were not uncommon
in the Boulogne market ; some reached a length of three feet and
upwards. I was informed by the keeper of the aquarium that
their French name was " Roussette."

Transverse Section of Human Molar (PI. XXIV., Fig. 13) is
described in the explanation to the plate. Will some member
illustrate for us the structure of human teeth in their various forms
by vertical and horizontal sections ? Then follow it up by sections
of pachydermatous teeth — rodent, carnivorous, lacertine, piscine,
etc. They would form an endless series of beautiful and instruc-
tive objects, especially if fossil teeth were included, and would be
most interesting. Tuffen West.

There has been established in Berlin a People's Society for
Natural Science, the chief object of which is to offer scientific
lectures that will be interesting to those having no technical know-
ledge of the subject. The first lecture before the Society was given
by Di. Forster, Director of the Royal Observatory, and entitled
"Conditions and Beginnings of Life on the Earth." — Science.

[ 8S8 ]

Sclcctc^ IMotcs from tbc Soctct^'a
IRote^Booke.

Spatangus. — I find in Maunders' Treasury of Nat. History that
this species of Echitioitermata is ahiiost always found buried in the
sand. They feed on minute animals abounding therein, their ali-
mentary canal beiny filled with sand cont;iining them. As their
power of locomotion and prehension is very small, it is difficult to
imagine how such an animal can obtain sufficient nutriment for
its subsistence. E. Lovett.

Dermestes lardarius.— I can attest as to the nuisance these
fellows are to a cabinet, and find a good plan to adopt is to exa-
mine the drawers carejully occasionally, and remove any specimens
under which a little dust is to be seen, as, whenever any of this
dust appears under a beetle or moth, it is certain an intruder is
commencing operations.

Several of these beetles, together with some of their larvae, were
found dead in some Egyptian mummies in the inside of the bodies,
and It was thought they got there before the final embalming took
place. E. Lovett.

Hairs of Larva of Lepidoptera form interesting objects, those
of Ardia caja (the one under consideration) being the general
type ; the cocoons of moths being the best to illustrate them, as
the larva intermingles its hair with the silk of the cocoon, and the
two may be seen well together. The tuft hair from the larva of
Orygia antiqua are very curious indeed, and it has just occurred
to me that, just as the nails and horns of animals represent hairs
solidly bound together, so probably the spines at the tail of the
larva of the Sphingidce may (if cut into longitudinal*' sections)
exhibit all or a part of the characteristics of consolidated hairs.
The spines of the larva of Vanessa urtica are curiously formed,
and represent a short, branched hair, though literally a spine ; and
the skins of smooth larvte, of which there are, of course, an
immense variety, exhibit, when viewed microscopically, a number
of very short, stumpy spines, frequently double, which are the

"" Would nol transverse sections show this better? — Ed.

384 SELECTED NOTES FROM

representations of the bunches of hairs of the so-called hairy
larvae. E. Lovett.

Caligus MuUerii,— I took several of the Caligus Mullerii on
codfish here. On a lank and sickly fish of about ten pounds
weight, I found as many as five dozen. 1 observed that only a
very few of these parasites were to be found on healthy and well-
fed fish ; but the one I have referred to as bearing so many had
apparently met with an accident, whereby the sight of one eye had
been destroyed, and as the injury appeared to be of old standing
I judged that deficient nourishment had been consequent on
defective vision, and analogy seemed to teach that such deficient
nourishment had favoured the increase in the number of these
parasites.

During some two days I must have examined over two hundred
fish ; but my observation does not confirm the opinion that the
Caligus particularly affects the gills or mouth, for I found but few
specimens in this position. It was a congener of this fellow
{Lerneopoda) which is mentioned by Scoresby as attaching itself to
the eye of the shark, and by piercing the tissues destroying the
vision of its victim ; but the damage to the Gadus Morrhua, from
which this specimen was taken, appeared rather to have had its
origin in other causes. There is, I believe, and I think I have
seen (before I knew of its existence), an animal living parasitically
upon this entomostracan parasite. W. Lane Seer.

Dog-Fish.— Mr. Tufifen West's very accurate sketch (PI. XXIV.)
is really a portrait from life of what Mr. W. says he "takes to be"
the smaller spotted dog-fish. My friend, Mr. Henry Lee, has
been most successful in breeding them in the Brighton Aquarium,
and has actually induced, and then watched and recorded, the
process of egg-laying by the fish, exemplifying by actual observa-
tion the uses as well as the application of the long gelatinous
tendrils (three to thirty feet) which are attached to the corners of
the (mermaid's purse) egg.

I believe that the skin of both the larger and lesser spotted
dog-fish is applied commercially in the manufacture of corn-rasps
sold by many druggists ; indeed, a chemist on the south side of
Fleet Street has, or had a short time ago (1875, Ed.), a whole pile
of these corn-rasps lying in his window, with a stuffed specimen of

THE society's NOTE-BOOKS, 385

the Scyllium suspended above them, though it occurred to me as I
passed by, that not one in a million who throng that busy thorough-
fare would be likely to discover the connection intended to be
conveyed. W. Lane Seer.

Cherry-Stone, Tr. Sec— It will be noticed that the grain runs
in three different directions : the outer in lines converging towards
the centre, the middle in longitudinal lines from end to end, and
the inner in a matted mass round the stone. W, M. Appleton.

Cuticle of Plants, To Prepare. — I have prepared some hun-
dreds of cuticles in past years by the following method : — Place
the leaf in a test-tube in a little solution of caustic potash {liquor
potassce, of druggists), boil for a short time, varying in the case of
different leaves from a few seconds to several minutes ; turn the
contents of the tube into a beaker of hot water and swill round,
and then removing the leaf open it out with a broad scalpel under
water. If the leaf be snipped round one edge before it is placed
in the potash solution, it will open out spontaneously.

The vascular system of the leaves are remarkably well prepared
in this way, the minute terminations remaining attached, and in
many cases manifesting special characteristics. See on that point
Herbert Spencer's Principles of Biology and reprint of a paper (in
that volume, I think) read by him many years since before the
Linnaaan Society.* H. Pocklington.

Chrysis ignita. — Nothing can exceed the splendour and bril-
liancy of the Chrysididcz. Latreille compares these insects to
precious stones, and supposes that their superb colour dazzles
their enemies, and so facilitates their escape. They seem timid,
for directly they are touched they roll themselves into a ball.
They have a very weak sting, placed at the extremity of their long
telescopic-formed oviduct (only able to pierce soft bodies). This
flexible tube can be extended to a very great length, and is fre-
quently exserted. It is brownish-ochre in colour, the terminal
plate of the abdomen beneath being generally black.

These insects are not uncommonly found on walls and windows
in very hot weather, and their brilliantly-coloured thorax and abdo-
men, as well as their velvety black antennae, and yellow or blue-

* Linn. Soc. Trans., xxv., 405.

386 SELECTED NOTES FROM

green backs thickly and coarsely punctured, clothed with upright,
soft, grey hairs, make beautiful objects for the microscope.

E. E. Jarrett.

Ditto. — The Chrysididce are indeed among the most beautiful
of our insects. They are parasitic upon the insects, mostly affect-
ing the larvae of solitary Hymknoptera, among which the well-
known Sand-fly {Oolynerus ?) is a frequent victim. This insect is
wonderfully persevering in its attempts to deposit its eggs. The
sting Hke ovipositor is capable of inflicting a smart prick when the
insect is moved to anger. J. H. Wilson.

Some Additional Remarks on Finishing Slides.*
I am very much averse to making mounts conspicuous by
ringing them, which I think white varnish does without in any way
adding to their strength. It seems quite unnecessary to ring a
balsam mount, which, if made of fairly colourless balsam, looks
very nice, if carefully done, without any cleaning off". It is only
balsam which has been unduly heated and dried (before making
up with xylol or other solvent), which cracks off, and such mounts
are unpleasantly yellow, not to say brown. The balsam I have
always used looks quite colourless on the mount.

For mounts in fluids where it is absolutely necessary to put a
ring to prevent the fluid escaping, I much prefer plain gold-size,
which looks well, is transparent like the mount, and never cracks.
I generally go over rings of gold-size three times. J. Gifford.

On reading the remarks on finishing slides, I at once asked,
" Why ring balsam slides at all ? " To add black, white, or black
and white, or coloured rings to such a slide as Fig. 2, is as useless
as "to gild refined gold or paint the lily." Nor do I think that in
a climate like ours such ringing adds anything to the security of
a balsam mount. The superfluous balsam would serve nearly
the same purpose as a ring of a different material, and, unless
excessive in quantity or very uneven, is surely no dis-sight. It
may be. however, that balsam slides in :i hot climate require ringing
with some substance not so easily affected by heat. A friend of
mine returning from the ^Antipodes found on reaching England

* For earlier notes on this subject, see this Journal for 1894, p. 102, etc.

THE society's NOTE-BOOKS. 387

that the heat on and near the Line had melted his balsam, and
had allowed the cover-glasses to fall to the bottom of the racks.
Even then, if the slides had lain flat, no harm might have
happened

There is, I think, a practical inconvenience in ringing slides
that require to be examined with a high power, and that is, you
cannot slide your slide off the stage without screwing up the micro-
scope, and so losing your focus ; at least, this is so with a simple
stage like that of the Hartnack microscope. Of course, when one
comes to deal with deep cells, either for balsam or glycerine,
ringing and finishing become of first-rate importance. How
almost invariably the glycerine slides are spoiled, or at least
damaged, before they have completed the circuit of the P. M.S.
Farrant's medium, ringed with asphalte, stands much better than
glycerine. R. S. Pattrick.

I own to being very much interested in the subject on
mounting and ringing slides. For years I have followed the idea
given me by an old friend, and use various colours for the different
groups of slides, viz. : — Green for vegetables ; blue for diatoms ;
purple for insects ; red for animals ; and white and black for
polariscope objects.

I get a small tube of oil-colours, and squeeze a little into a
homoeopathic bottle ; then I pour a little benzole in and let it soak
for a day or two to take up the oil; then I pour away the oily
benzole and put in some fresh, and all is ready. Having ringed
on the zinc-white cement, I at once apply the colour of the ring,
as desired ; the benzole takes it over to the zinc-white, and the
slide is done. The advantage is that if you are showing slides to
people, you know from the colour of the ring the class of subject
you are showing, and when you want to put away your slides you
perceive at once where they are to go. I admit that there is no
further use in ringing slides, but why may not the outside look
pretty ? A. Clarke Smith.

In my opinion, by far the neatest way to finish a balsam slide
is to put a ring of balsam on instead of zinc white.

John E. Fawcett.

388 SELECTED NOTES FROM

If an object is worth the labour of preparing, surely it deserves
finishing in a neat manner. For some years I have used zinc
white with a red or black band. J. Phillips.

Some Slides from Jersey, contributed by Mr. W. Pumphrey.

My contribution for this year to the Postal Microscopical
Society consists of twelve slides prepared at the Biological Labo-
ratory, Jersey, and may, I think, be taken as fair specimens of the
style of work of that establishment. They are selected from three
of the lower orders — viz., the Sponges ; the Actiniae ; and the
Echinoderms.

Sponges.— The sponges form almost, if not quite, the lowest of
animal tribes. They consist of a gelatinous mass, supported and
maintained in position by a skeleton composed of spicules. Some-
times the spicules are siliceous and sometimes calcareous. The
simplest form is that of a small mass of gelatinous matter, sup-
ported by these spicules, so formed as to imbibe from the outside
through minute passages the liquid (whether it be salt water or
fresh) in which the organism lives, and from which it derives its
nourishment ; the liquid being ejected from a central orifice. By
a series of buddings the simple cell becomes built up into a large
aggregate of individuals.

No. I is an entire specimen of a sponge, with calcareous
spicules. The specimen consists of a small group of associated
individuals, in different stages of growth. The spicules in this
species are trifid.

No. 2 is a section of another calcareous sponge ; the spicules
are more robust ; and in making this section the greater part of
the spicules have been broken. Those in the interior of the
organism are very much larger than those near the exterior, and
which by their close aggregation and interlacing give firmness to
the exterior part.

No. 3 is a section of a siliceous sponge ; here the spiculse are
of two distinct forms. Scattered through the mass are minute
spiculse, having four points, while others of simple acicular form
are scattered irregularly about. The specimen also contains large
numbers of Sterrasters, or oval spicules, which are closely aggre-
gated towards the exterior of the organism.

THE society's NOTE-BOOKS. 389

Spongilla fluviatilis.— No. 4 is a section of a fresh-water sponge
{S. fluviati/is). This specimen is hterally filled with statoblasts or
winter germs ; these are seen to be built up with spiculae of a dif-
ferent make from those of the mass — bi-rotate — with eight or ten
points.

The four following slides are from the family of the Adinice, the
Sea Anemones. This group of animals consist, in their simpler
forms, of a gelatinous sac, unsupported by spiculae, with a cavity
which acts as a stomach, and of which the orifice is surrounded by
a row, or rows, of tentacles. In some species the soft matter of
the animal, as in the SerlularicB, is supported by a horny pol3'^pi-
dom ; in others, as the Alcyonium, the soft matter is stiffened by
numerous short, calcareous spiculae ; while in others, as the Corals,
the polyps secrete a skeleton of calcareous plates, within the
limits of which it can withdraw itself when disturbed. Our speci-
mens are confined to the first and third of these groups.

Adamsia rondoletta. -No. 5 is a section o{ Adamsia ro7idoletta.
The Adamsia are sea anemones that are almost always found
adherent to the vacant shells of certain molluscs ; they affix them-
selves round the orifice of these shells, whence they are called
" Cloak anemones," and the shell is very often found to be also
tenanted by a hermit crab.

On No. 6 are sections of the anterior and posterior parts of
Peachia hastata, an anemone which buries itself in the sand, having
the power, at will, of protruding the anterior part through the sand
and displaying its row of tentacles.

Alcyonium dig^itatum.— No. 7 comprises sections of Alcyonium
digitatum (Dead Men's Fingers), one of the composite ActifiicE
that secretes calcareous spicules, which in the specimen are seen in
situ. It will be noticed that they are closely aggregated towards
the exterior of the animal, giving it solidity and firmness. The
section also shows the polyps occupying cells near the exterior of
the composite animal.

No. 8 is one of the polyps of Alcyonium digitatum detached
from the mass, in order to show its analogy with a simple actinia.

The remainder of the slides are preparations from the class of
animals of which the ordinary Star-fish (Cross-fish) is the type.

390 SELECTED NOTES FROM

No. 9 is a transverse section of one of the arms of the common
star-fish, Uraster rubens, and No. lo a longitudinal section of the
same, displaying very clearly some of the wonderful arrangements
of the star-fish group.

No. IT, a ventral section through Asterina gibbosa, one of the
smaller species of the star-fish family.

No. 12, anchors and plates of Synapta digitafa in sitit. The
Synapta, or Sea Cucumber, belongs to the Echinoderms, but is a
transition form, connecting them with a more highly organised
group. Instead of having a stiff, shelly covering, through which
the organs of locomotion and prehension protrude, the Sea Cucum-
bers have an integument of a leathery consistency, and embedded
in the integument are to be found the various spines and plates so
well known in collections of microscopical preparations. In this
section they are seen in situ in a portion of the integument.

William Pumphrev.

Alcyonium digitatum.— Slide No. 8 is a very beautiful slide of
a polyp of Alcyonium diqifatum ("Dead Men's Fingers." "Cows'
paps," "Mermaids' Fingers," etc.). A. digitatum is typical of the
order Alcyonaria. It is met with as deep as seventy fathoms, but
is common in much shallower seas. It is widely distributed, and
is about equally abundant in tropical and temperate waters. The
Alcyonaria date back to the cretaceous period ; when dredged up
it is repulsive in aspect, and has thus earned its not very attractive
common names ; but placed in sea water, its sponge-like mass
distends, becomes pellucid, and from all parts of its surface num-
bers of exquisite polypes, of which the mounted specimen is one,
expand their star-shaped crown of tentacles, and the previously
uninviting mass becomes an object of extreme beauty.

The tentacles are fringed, and within, circulating currents may
be observed finding their way up one side and down the other,
following the course of several fringes ; by the action of their
ciliated walls they seem to fulfil the function of a respiratory
system.

The skeleton is sclero-basic and spicular, and is well shown on
the slide with a ^-in. objective.

THE society's NOTE-BUOKS. 3U1

The slides of Si)onges and Spongillae are most interesting.
Going through a series of locally collected sponges with a friend
at Ramsgate a few weeks ago, we could neither of us determine
whether the axis of the bi-rotate spiculae are hollow or no (slide
No. 4), a bright spot in the centre of the radiating points seeming
almost to indicate this. Perhaps members working with higher
powers can determine (my highest power is 3^-in. with B eyepiece).

J. Lucas.

Observing the transverse section of the Burrowing Anemone
with a i-inch objective, observe the three body layers — ectoderm,
mesoderm (stained crimson in the section), and endoderm. The
ectoderm contains the stinging cells, or nematocysts, with which
the anemone paralyses and kills its prey. The mesogljea is com-
posed of muscular tissue ; the endoderm tines the entire body-
cavity in all its chambers with a coating of ciliated cells. Note
the oesophagus (the round circle in the middle). In this specimen
the section has been slightly crushed by pressure of the cover-glass.

Notice also the short, pouch-like outgrowth from the oesopha-
gus ; this is the siphunoglyph. Most anemones have two of these,
but Peachia has only one. These siphonoglyphs are angles which
bound the extremities of the mouth-slit ; they are continued down-
ward into the oesophagus as deep, richly ciliated grooves, and
remain open even when the animal is greatly contracted. They
appear to be useful in keeping up a constant flow of water through
the oesophagus.

Note also the twelve mesenteries which serve to break up the
great body-cavity into a number of radial longitudinal chambers.
These mesenteries are arranged in pairs; some reach across to the
oesophagus, and are called primary mesenteries ; others fall short
of it, and are called secondary mesenteries.

Observe the ridges on one face of the mesenteries, and notice
in the section muscle fibres forming a beautiful arborescent pat-
tern. These are the muscles which pull down the tentacles and
mouth disc, so as to shorten and retract the animal. The accom-
panying rough illustration may serve to explain these remarks.

Unsigned.

392 SELECTED NOTES FROM

EXPLANATION OF PLATES XXII., XXIII., XXIV.

Plate XXII.
Fig. 1. — Arborescent Crystallised Silver.

,, 2. — Represents a portion of the specimea shown with spines
partially seen, in different positions, x 25.

3. — Figure of Spatangus purpureus from above, to show the
form of the shell ; m. indicates the position of the mouth,
which is on the under surface ; p. v., position of the vent.

,, 4. —Base of a large spine, to show the cotyloid cavity, the strung
ridge for attachment of muscles which move it, and the
rectangular form of the meshes in its calcareous network.

,, 4a. — Sectional view of the spine, taken at about two-thirds of the
length. X 20.

,, 5. — Truncated column on which the spine is placed, having at its
top a smooth, rounded eminence, with depression for attach-
ment of a round ligament. x 20.

,, 6, — Diagram of the parts, in sectional view: — Sp., Spine;
rd., rd., Hidge near its base for muscular attachment ; r.l.,
Round ligament ; ah. m.. Abductor muscle, which, acting at
a disadvantage, has its attachment both above and below to
a projecting ridge ; ad. m.. Adductor muscle.

,, 7. — Portion of Seaweed, with Angihinaria dilatata attached.

,, ^.—Anqninaria anguhia, with polyp partially protruded.

,, 9. — Head of same, more enlarged, and horse-shoe-shaped chitin-
ous lower jaw.

,, 10. — Another specimen, showing repaired fracture of the neck.
ad. m.. Adductor muscle of jaw; ah. m. , Abductor muscle
of neck ; r.f., r.f.. Place of repaired fracture. Near the
top, towards the right hand side, are some Diatoms, probably
Bhahdomina minuta.

Plate XXIII.

Eggs op Parasite of Common Fowl.

Fig. 1. — One of the Eggs, showing the triple coronet of horny cilia
surrounding the mouth ; the hexagonal areolation, seldom so
strongly expressed as in the figure, the lid, and the glutinous
material at the place of attachment.

,, 2 and 3. — Further illustrate some of these points.

,, 4. — Illustrating some points in a species cf Scatophaga, S . The
figure represents the thorax and abdomen, and is specially
designed to show the number and position of the segments
composing them, and of the spiracles.

h., Position of the head ; tx. , Thorax, composed of p.i.cc.,
Prothorax ; in.s.x., Mesothorax ; m.t.x., Metathorax. The
abdominal segments are denoted by the letters a.s., with 1.
2, 3, etc., for first, second, and third abdominal segment, and
so on ; p.t.x.s., Prothoracic spiracle; m.t.x.s., Metathoracic

Joupnal of iMiL'HoseopV. 3p3. Scp. , \ ol. 6, Plalc: 22.

^^C^'

ad.m-Sf :i

Joupnal o| Mlepogcop^, 3p3. Sep,, Vol. 6, Plate 23.

tx

:^iSS!5?v. '"^% msx \ ptx<^.

abdomen ^^

/ 6as/^'

Ul

1 117 ,'

•■" A '\

,'ll

genital'

3 as 2as "j-^^ j^tx ,!_/

' / i

Joupp-al of Mlevozeof^, SpSl Sep., Vol. 6, Plate 24.

^3

J'^

-I

fTifj /^/.^ :f

^

\iip

4\

i«f^

t ^ f

*

^ x^.r

y^/"

5

' - /

V 4^ , ,^

> J

/

'^^'^

'tl

■^

s'M^:^^--

/ '

^-*AJ?fWn ^--^

^

^^■A\.^

,

.^^j^r

ri'-''

,^

,

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''<

THE society's NOTE-BOOKS. 393

spiracle. The Roman numerals are placed in their respective
segments.

Fig. 6. — Hairs from Caterpillar of Tiger Moth.

a, Three hairs slightly magnified, x 10.

b, Base of a brown hair, x 50.

c, Central portion of one of the grey hairs, x 50.

d, Apex of a brown and of a grey hair, x 50.

,, G. — Scales from wing of Tinea vestianella.

a, Long, slender, hair-like scale.

b, Bifurcate ditto.

c, One of the same class, with three forks.

d, Large characteristic scale from central portion of wing.

e, Smaller scale belonging to the same class.

/, Small translucent scale, having perhaps sensory functions.
g, Very minute scale, perhaps ill-developed.
iVofe.— These scales should have been separated from the
Hairs on the Plate by a vertical line. We observe
also the numeral 6 is omitted.

Plate XXIV.

Fig. 1. — Dermestes lardarins, Bacon Beetle, from living specimen, x 3.

,, 2. — Left Antenna, showing the number of articulations, x 25.

,, 3. — Fore tarsus from left side. \

,, 4. — Middle tarsus do. > x 25.

,, 5. — Hinder tarsus do. )

,, 6. — Portion of compound eye of the left side, showing the pyra-
midal sclerotics of several of its facets.

,, 7. — Ovipositor. The Roman numerals denote the segments
represented by the joints composing it.

,, 8. — Reduced figure of a drawing made from the life, in the
aquarium at Boulogne-sur-Mer, of what I take to be the
small spotted Dog-Fish.

,, 9. — Portion of the skin, with scales, from specimen on slide, x 15

,, 10. — Scales of Scyllium caniciditm, with the expanded base upper-
most, X 25.

,, 11. — Side view of another scale of the same, x 26.

,, 12. — Sectional view of same, specially given to show the outline of

the tooth-like plate of the scales, x 25.

The three latter figures, taken from specimens separated by

the action of potash, kindly given me by another member.

,, 13. — Transverse section of Human Molar Tooth, x 3, showing —
e, Enamel; d., Dentine; o.d., Osteo-dentine, or "cement,"
which appears to have invaded and completely filled the
central pulp-cavity, with devarications therefrom.

All drawn by TuflFen West.

Erratum.— Explanation of Plate XXII., Fig. 2, p. 392, should read
"Represents a portion of Spatangus purpureus, with," etc.

iNTEfiNATIOXAL JOURNAL OF MICROSCOPY AND NATURAL SCIENCE.

Third Series. Vol. VI. aa

[ 394 ]

riDicroscopical ^ccbnique.

Storax as a Mounting Medium.— Permanent preparations can
be mounted in storax, according to Dr. J. H. Piffard (Medical
Record, 1895, P- 547)' ^^ i^ t)e prepared as follows : — The storax is
liquified on a water bath, then filtered through two or three thick-
nesses of cheese cloth, on a hot-water funnel, and when cold mixed
with an equal weight of xylol. Shake well several times daily for
at least two weeks, then filter two or three times through absorbent
cotton or Swedish filter-paper, and evaporate at a gentle heat to
the consistency of treacle. Finally, to each two parts of the fluid
add three parts of naphthaline monobromide, and heat gently
until a clear amber-coloured fluid is obtained. Preferably, the
refractive index of the medium should be brought to i'62 5, by
adding more of the ingredient that may be found deficient, and
the product will then be found suitable for work with the highest
powers. — Phar?naceuiical Journal.

Brown Cement, suitable for microsco ic wor —The Chemist
and Druggist recommends either a thick solution of shellac in
vegetable naptha, or of gutta-percha in chloroform or bisulphide
of carbon.

To find Micro. Objects.— It may not be generally known to
those who mount their own slides that much good material can be
found during the winter by examining the stems of any dried
plants in the hedgerows, as, e.g., Nettle, Cock's-foot Grass, etc.
In this manner various and often rare insects can be taken in fine
condition The most productive stems are those 7wt in a vertical
position, as when standing at all upright the rain can enter, which
makes it too uncomfortable for insects to take up their winter
quarters there. It is a good plan, when the day is very cold, to
take the stems home in a paper bag, and examine them over a
sheet of white paper. Moss collected in the woods will also yield
good results, especially in the beetle tribes. C. J. Watkins.

MICROSCOPICAL TECHNIQUE. 395

Nutrient Gelatine.— To prepare this, first make beef broth by
mincing 450 gm. of lean beef, free from all fat and connective
tissue, and boiling for half-an-hour in a large flask, with a litre of
distilled water. Filter and make up to one litre with water, then
add sodium chloride 5 gm. and pure peptone 10 gm. Heat the
mixture in a flask on a water-bath at 100" C. for an hour, shaking
from time to time. Now cautiously add concentrated solution of
sodium carbonate until faintly alkaline, and again heat at 100^ C
for half-an-hour. Next, allow 100 to 120 gm. of sheet gelatine to
soak in the broth for half-an-hour ; heat slowly on a water-bath
until the gelatine is dissolved ; neutralise carefully, and again heat
for half-an-hour. Then add the white of an egg, heat till all the
albumin is precipitated, and finally filter through two layers of
moist filter-paper, on a hot-water funnel, into sterilised flasks, and
sterilise on a steam steriliser for twenty minutes on each of two
successive days. — Pharmaceutical Journal.

Inoculating Culture Tubes.*— Beneke recommends that gelatin
culture tubes should be inoculated by making a puncture at the
side of the medium close to the glass. The advantage of this
method over the older plan of inoculating the mass in the middle
is that the growing culture can be microscopically examined from
the outside and various details made out, such as the nature of
the growth, the comparative appearance of colonies near the
surface and those situated more deeply, and the presence of one
or more distinct organisms. If the tubes used have the opposite
sides flat and parallel, such examinations will be still further
facilitated.

A New Method of Preparing Serum Agar-Agar.— Drs. Kant-
hack and Stephens suggest in the Lancet the utilisation of patho-
logical serum, such as ascitic, pleuritic, and hydrocele fluids, of
which there is always a large supply at a hospital, for the prepara-
tion of serum agar-agar culture medium for the separation of the
typical diphtheria bacilli. The following method gives a beautifully
clear and transparent medium in less than half-an-hour: — To every
100 c.c. of serous exudation, 2 c.c. of 10 per cent, caustic potash
is added ; i '5 to 2 per cent, of agar-agar previously soaked in

*Cent,f. Baki. in Pharm. Journ.

396 MICROSCOPICAL TECHNIQUE.

acidulated water is next added. The mixture is then boiled in a
Koch's steamer until the agar is dissolved, after which it is filtered
through a hot-water funnel, and 4 or 5 per cent, of glycerin added
to the filtrate. The medium is now ready for sterilising in test-
tubes in the ordinary way. Sometimes the serous fluid is very rich
in albumin. Before adding the potash, a little should, therefore,
be boiled in a test-tube ; if it becomes practically solid or contains
a large excess of albumin, it should be diluted with at least twice
its bulk of distilled water. — Pharmaceutical Journal.

The Staining of Cellulose.— Varying results may be obtained
on staining cellulose, according to its age, young and soft tissue
absorbing stains with least difificulty, whilst maturer tissues may
remain unaffected by the same stains. Dr. E. G. Love studied
the subject, and made comparative tests with a view to determining
the value of different stains. He found that some stains — such as
hsematoxylin — require no mordant to fix them, whereas carmine
stains generally require a mordant, such as alum. The mordant
may be mixed and applied with the stain, or it may be used sub-
sequently; or, again, the tissue may be impregnated with the
mordant before the stain is applied. There are thus four ways of
staining tissues. The last-mentioned was found best for prepara-
tions which are difficult to stain. In the specimens of cotton and
linen fibres treated, the cellulose was, of course, not in such a
receptive condition as young and soft cellulose tissue, for in pro-
portion as the cellulose increases in density it affords a greater
resistance to the action of stains. Thus, Grenacher's solution of
carmine in alum was found to produce a slight reddish tint only
after twelve hours ; Thiersch's solution in oxalic acid a dull rose
colour after eighteen hours ; and borax carmine, with oxalic acid
as a mordant, was no better than Grenacher's solution. The
cotton fibres were stained light blue by hsematoxylin and alum, but
any depth of colour could be obtained by applying a mordant
(alum, aluminium, copper sulphate, or acetate) first. Methyl green
produces a deep green when the fibre has been previously mor-
danted, but light green if stained first. — Pharmaceutical Journal.

[ 897 ]

A Text-Book of Histology, Descriptive and Practical, for
the Use of Students. By Arthur Clarkson, M.B., C.M.Edin. ; with 174 ori-
ginal coloured illustrations. 8vo, pp. xx. — 554. (Bristol : John Wright and
Co. London: Simpkin, Marshall, and Co. 1896.) Price 21/- net.

It is with much pleasure that we direct the attention of our readers to
this really magnificent work, the purpose of whose author has been to furnish
the student of Histology with both the descriptive and practical parts of the
science. The first two chapters are devoted to the consideration of the general
methods of Histology ; subsequently, in each chapter, the structure of the
tissue or organ is first systematically described ; the student is then taken his-
torically over the specimens illustrating it ; and, finally, an Appendix affords a
short note of the methods of preparation. We give a summary of the more
important subject-matter of the various chapters : — Chaps. I. and II., General
Methods ; Chaps. III.— VII., The Simple Tissues ; Chap. VIII., The Vascu-
lar and Lymphatic' Systems ; Chap. IX., The Spleen and Ductless Glands;
Chap. X., The Respiratory System; Chaps. XL and XII., The Ahmentaiy
Canal; Chap. XIIL. The Kidney, Ureter, and Bladder; Chap. XIV., The
Skin, Epidermic Appendages, and Termination of the Sensory Nerves ; Chap.
XV., The Reproductive System; Chap. XVI., The Eye, Ear, and Olfactory
Membrane; and Chap. XVII., The Nervous System. There is also an
exhaustive index. The information given throughout the entire work is tho-
roughly plain and concise. Besides the 174 beautifully coloured plates, there
are 22 wood engravings in the text.

Rheumatoid Arthritis : Its Pathology, Morbid Anatomy,
and Treatment. By Gilbert A. Bannatyne, M.D.Glas., M.R. C.P.Ed. 8vo,
pp. xii. — 173. (Bristol : John Wright and Co. London : Simpkin, Marshall,
and Co, 1896.) Price 7/6.

Chap. I. of this work is Introductory and Historical ; Chap. II. treats of
the /Etiology and Pathologj' of the subject ; Chap. III., Pathological Anatomy
and Bacteriology. These chapters are followed by others on Diagnosis, Prog-
nosis, and Treatment.

The Ritual of Health for the Grown. By H. Cooper
Patten. Cr. 8vo, pp. 125. (London: Jarrold and Son. 1896.) Price i/-

This, the first of three volumes in course of pubhcation, is intended for the
guidance of men between the ages of 30 and 60 and of women five years
younger, and contains an amount of good common-sense information, from
which all may derive much profit. We regret that the book came to hand too
late to receive the careful reading we should otherwise have liked to have given
it. We hope to treat the succeeding volumes of the series in a more satisfac-
tory manner.

Die Naturlichen Pflanzenfamilien. By A. Engler-
Nos. 136, 137, 138, 139. (London : Wilhams and Norgate. Leipzig : Wil-
helm Engelmann.)

These beautifully illustrated parts contain descriptions of the Pezizine?e
(concluded), Phacidiine?e, and Hysteriinere, by G. Lindau ; RhamnaccK (con-
cluded), by A. Weberbauer ; Vitaceas, by E. Glig ; Meliacete (concluded), by
H. Harms ; Trigoniacete and Vochyiacere, by O. G. Peterson ; Tremandracete
and Polygalaceas, by R. Chodat ; and Dichapetalacex, by A. Engler.

In these parts there are 665 figures, comprised in 95 illustrations.

398 REVIEWS.

W, & A. K. Johnstone's Botany Sheets for Beginners,

Nos. I and 2. (Edinburgh and London. 1896.) Price 3/6 each.

These are finely coloured sheets, mounted on canvas and rollers, suitable
for Schools and Science Class Rooms.

Sheet I. treats of the Typical Root. Fig. i shows the Germination of an
Acorn ; 2, Matured Tap-Root System of Sunflower ; 3, Annular Roots of
Ipecacuanha ; 4, Scabiosa, or Devil's Bit ; 5, Ciarden Beet ; 6, Carrot ;

7, Yellow Turnip ; 8, Snake-root ; 9, Moniliform Roots of Pelargonium ;
10, Drop- Wort ; 11, A Diagrammatic View of a Tap-root with its Branches ;

12, Apical portion of a Typical Root, as seen in Longitudinal Section ;

13, Germination of Maize ; 14, P'ibrous Adventitious Roots of Meadow Grass ;
15, Tuberous Adventitious Roots of Dahlia; 16, Orchis maculata ; 17, Dia-
grammatic section of Tubers of same ; 18, Simple Root of Lemna ; 19, Ivy ;
20 shows the parasitic (metamorphosed) root Mistletoe ; 21, Rhizoids of Algae;
22, Common Mushroom.

Sheet II. treats of Stems. Fig. i shows St. John's Wort ; 2, Lesser Peri-
winkle ; 3, Dutch Clover ; 4, Strawberry ; 5, House Leek ; 6, 7, Mignonette ;

8, Buds of Sycamore ; 9, White Dead Nettle; 10, Daffodil; 11, Fox -tail ;
12, Hop; 13, Convolvulus ; 14, Vine; 15, 16, Furze; 17, Leaf-like Branches
of Butcher's Broom ; 18, Cactus ; 25, Hop-stem, with parasitic roots of Dodder.

The explanatory text at the bottom of each chart is good.

How to Study Wild Flowers. By Rev. Geo. Henslow,
M.A., F.L.S., F.G.S., etc. For the Use of Schools and Private Students.
Cr. 8vo, pp. 224. (London: Religious Tract Society. 1896.) Price 2/6.

This little book is intended to enable the student to rapidly acquire an
accurate knowledge of typical British wild flowers, and to show him how he
may attain this without other assistance. It is very plainly written and nicely
illustrated with 47 engravings.

The History of Mankind. By Prof. Friedrich Ratzel.

Translated from the Second German Edition by A. J. Butler, M.A. ; with
Introduction by E. B. Tylor, D.C.L., F.R.S., etc. Vol. I. Royal 8vo, pp.
xxiv. — 486. (London: Macmillan and Co. 1896.) Price 12/- net.

This grand book offers those who are beginning anthropological work the
indispensable outline sketches of the races of manknid, especially of the savage
and barbaric peoples who display culture in its earlier stages, thus aiding the
great modern nations to understand themselves. Besides a map, there are nine
beautifully-coloured plates and a great number of illustrations.

A Manual of North American Birds. By Robert Ridge-
way. Illustrated by 464 outline drawings of the Generic Characters. Second
edition, royal 8vo. pp. xiii.— 653. (Philadelphia (U.S.A.) : T- B. Lippincott
Co. 1896.) Price 35/-

The first edition of this fine work appeared eight years ago. Smce 1887
ninety-one species and sub-species have been added to the North-American
fauna. A description of these has been added in the Appendix ; whilst the
whole work has been carefully revised and corrected. The drawings of chief
generic characters, which are more or less in outline, cover 124 plates.

British Butterflies ; being a Popular Handbook for Young
Students and Collectors. By J. W. Tutt. Cr. 8vo, pp. 479. (London :
George Gill and Sons. 1896.) Price 5/-

It is with much pleasure we notice this volume of " Hedgerow and Wood-
land " series. From it the young entomologist may learn the main facts relat-

REVIEWS. 399

ing to the variation, iiabits, and life-histories of some of our British Butterflies,
and in which he will find an attempt to sei clearly before him the structural
peculiarities of their eggs, larva;, pupae, and imagines, those peculiarities which
are now considered of importance by systematisis being most fully dealt with.

The chapters on the Egg, Caterpillar, Chrysalis, and Imago will give the
collector the clues he requires to follow up the more advanced branches of the
study. The chapters on Collecting, Killing, Setting, and Preserving Insects
will be found valuable, being based on Mr. Tutt's long practical 'experience.

There are lo fine plates and 45 illustrations in the text. The book forms
a nice companion volume to that on British Moths, noticed in our April'part.

Insects and Spiders : Their Structure, Life-Histories, and
Habits. By J. W. Tutt, F.E.S. Cr. 8vo, pp. 116. (London: George Gill
and Sons. 1896.) Price i/-

This, which is Part II. of Gill's Practical Series of Object Lesson Books,
describes the General External Characters, Internal Organs and their functions,
and the Metamorphoses of Insects, with descriptions of the different orders of
Insects, in a series of lessons which are meant to be merely suggestive, the
point aimed at being to lead the child to observe. There are a number of good
illustrations.

Earth Knowledge : A Text-Book of Physiography. By W.
J. Harrison, F.G.S., and H. R; Wakefield. Part I., 9th edition, and Part II.,
6th edition. Cr. 8vo, pp. 266 and 240. (London: Blackie and Son. 1895.)
Price 2/- each.

So considerable have been the changes and additions to these new editions

that they are practically new books. Care has been taken to bring them up to

date, and to embody the most recent discoveries in science. There are upwards

. of 220 illustrations in the two books, besides which both are accompanied by

good indexes.

By the Deep Sea : A Popular Introduction to the Wild Life

of the British Shores. By Edward Step. F.L.S. .Second edition. Cr. Svo,
pp. 322. (London: Jarrold and Son. 1896.) Price 5/-

To naturalists visiting the seashore we can recommend no more interesting
book than the one before us. It treats of all those things likely to be met with
— Low Life, Sponges, Zoophytes, Jelly Fishes, Sea Anemones, and the
rest. It contains more than 120 illustrations, is written m a popular style, and
cannot fail to interest every reader. Besides an Alphabetical Index, it contains
that which we seldom find in popular works — a Classified Index of Species
referred to. This we consider a very valuable addition, and one which authors
of similar books would do well to follow.

The Biological Problem of To-Day : Preformation or Epi-
genesis ? The Bases of a Theory of Organic Development. By Prof. Dr.
Oscar Hertwig ; translated by P. Chalmers Mitchell, M.A. Cr. 8vo, pp.
XX. — 148. (London: William Heinemann. 1896.) Price 3/6.

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A series of lessons adapted to the Elementary Stage of the South Kensing-

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A romantic interest belongs to the rise and progress of most of our indus-
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We consider the title of this book somewhat misleading, and are therefore
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In addition to describing the construction and method of using Galvanic
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Those about to use the lantern during the coming winter will find informa-
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The present volume is a thoroughly up-to-date one, and one which must
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This is No. i of Percy Lund's Popular Photographic Series. The peculiar
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This is another of the Popular Photographic Series, in which the details of
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The Junior Photographer, Summer Double No., Aug., 1896.
The Practical Photographer, Sept. Double No., entitled

Photography and Photographers, — This is a Japanese number, and is fitted
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These Journals are published by Percy Lund and Co., Ltd., London, and,
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Beginner's Guide to Photography, showing how to Buy a

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We have here practical remarks on Photographic Apparatus generally ;
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The Cat : Her Place in Society and Treatment. By Edith

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All are acquainted with the trite sayings of the late Mr. Spurgeon's Jolin
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We are mformed that the publishers of Mr. Spurgeon's sermons have just
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REVIEWS. 403

The Royal Natural History, Part 34. Edited by Richard

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In the present part is commenced a description of Sub-Kingdom EcHiNO-
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This part commences with Russian Language and Literature, of
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Work : The Illustrated VVeekly Journal for Mechanics. Vol.
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A glance at the index of this volume, which occupies nearly 8 pages, each
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This grand work was concluded a few months ago, but by an oversight we
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We think the next best thing to having actually seen the great Columbian
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and Visible Sound.

CTN

($y{Y^r

%iet of DMatcf^,

Anguinaria anguina

Plate
22

Page
376

Aphidivorous acarinae

17

369

Aphidivorous Hemiptera, Details
Arborescent Crystallised Silver

of

14
22

249
376

Capsus lanarius

Capsus lanarius, Details of

...

7

8

157
157

Cytoplasmic Crystalloids of Scilla
Dental Enamel, Structure of

patula... 5
i8, 19, 20, 21

113
... 361-367

Dermestes lardarius

24

381

Diatoms

,9

192

Diplodontus despiciens

...

16

313

Dog-Fish, Spines of
Eggs of Parasite of Fowl

...

24
23

381
378

Gryllus domesticus. Labium of

I

35

Hairs from Caterpillar
Hemiptera Heteroptera
Hydrachna geographica
Labium of Gryllus domesticus ...

...

23

13

3
I

378
249

55
35

Myrmecophelous acari

...

10, II

296

Micrometry

Molar Tooth, transverse sec. of

...

15
24

341
381

Nessea longicornis

...

6

143

Neuroptera and Orthoptera, Structure of

Labium of

2

35

Neuroptera, Wing Venation in ...

I

35

Fiona ovata and P. afifinis

12

272

Scatophaga ...

Spines of Spatangus ...

Wing Venation in the Neuroptera

23
22

I

376
376

35

[ 406 ]

3n^c|: to DoL Vh

-t>|)e-

Page
iVcari, Myrmecophelous - - - 296
Acid, Aspartic - - - - 85

Acrostichum alcicorne - - - 80
Adamsia rendoletta - - - - 389

Adaptation of Water-plants to their

Environment - - - - 61
Address, Presidential - - - i

Agar, Preparation of Clear Nutritive - 97
Agar- Agar, New Method of Preparing 395
Agate, Brecciated - - - - 131
Agate, Superstitions respecting - - 141

Agate, The Origin and History of - 129
Alcyonium digitatum - - 389, 390

Algae, Preservation of - - - 248
Alpine Rose, Leaf of the - - - 79
Alteration of Physical and Mental

Characteristics by Climate - 49

Ammonites pluvicostatus - - "78

Analysis of Steel, Microscopical - 93

Ananino Polishing Paste - - - 195
Anatomy, Comparative - - - 276
Anatomy of Imago of Capsus lanarius 249
Anemone, Burrowing - - - 391

Anguinaria dilatata - - - '377
Ant-Lion, Larva of - - - - 76
Ants and Orchids . - - - 295
Ants, Intelligence in - - - 128

Aphides, Predacious and Parasitic

Enemies of the - 35, I57, 249, 369
Aphidivorous Hemiptera, Anatomy of 172
Arborescent Crystallised Silver - - 376

Arctic Hail and Thunderstorms - 328

Aregma bulbosum - - - - 80

Aregma obtusatum. Spores of - 80, 81
Argon and Helium - - - - 122

Argon, Separation of - - -123

Arrow Poisons ----- 286

Artistic Preparations of Diatoms - 334
Aspartic Acid - - - - "85

Asterina ------ 78

Atypus sulzeri - - - - - 87

Aulacodiscus orientalis - - - 194
Aulocomnium androgynum - 77, 78

Bacilli from Phthysis - - - 208
Bailey, L. H., on Experimental Evo-
lution among Plants - - - 8
Balsam of Tolu - . - . 270

Page
Barbour, W. D., on Invisible Worlds- 239
Barbour, W. D., on Time, Space, and

Invisibile Worlds - - - 423

Bath Waters, The - - - . 209
Batrachospermum, To Mount - - 207
Bougainville ramosa - - - - 279

Bee, Wild, Parasite of - - - 86
Beetle from Butterfly Cabinet - - 381
Bergmehl ..... ig^

Berlin Society for Natural Science - 382
Binary Stars, The - - . - 316

Black Background for Mounting Spe-
cimens . - . - . 206
Blood, To see the Circulation of - 207

Blow-fly, Preparing and Mounting the

Head of - - - - - 89
Bodington, Mrs. A., Leaves from my

Note-Book - - - 45, 329

Bone, Human - ... - 208
Borax Carmine Staining Solution,

Improved - - - - - 96
Boring Sponges .... 204

Bostock, E. , on Myrmecophelous Acari 296
Bramble Brand - - - - 80

Breeze-fly, Foot of - - - - 200
British Hydrachnidae 55, 143, 272, 313

Brown Cement . - . . 3^^

Bryan, G. H., On the Origin of Insect

Transformations - - '57

Bryozoic Rock . . - - 206

Burmah, The Burning Tree of - - 148
Burning Diatoms on a Platinum Plate- 266
Burrowing Anemone - - - 391

Calathus cisteloides - . . - 306
Caligus Mullerii .... 384

Call-Ducks - - - - - 52
Canada Balsam . . - . 269

Capsus lanarius, Anatomy of - 249, 254
Carder Fish, Skin of ... 381

Carmine Staining Solution, Improved

Borax - - - - - 96

Cattle 45

Cebus and the Matches - - - 16
Cells of the Stratum Intermedium - 358
Celsia, Stamens of - - - - 78
Cellulose, Staining - - . . 396
Cement, Gelatine, and Fish Glue - 352

INDEX.

407

Cement, Good Liquid
Cement, Gum-lac
Cement, Resinous
Chalcedony

"Challenger" Dredgings
Cherry Stone. Tr. Sec. of
Chiton, The Development of

Page

■ 191

- 353

■ 353

- 131

- 195

- 385

- 2S1

Chlorophyll and Starch, Formation of- 142
Chrysanthemum - ,- - "331

Chrysis ignita ----- 385

Cleavage Cells, Cytotropism of - - 91
Climate, Alteration of Mental and

Physical Characteristics by - 49

Clothes Moth, vScales from Wing of - 380

Clutiona amarantha - - - - 87

Cnidaria ------ 278

Coal Measures, Coniferous Wood from 304

Coal Seciton - - . - - - 306
Cocoa, Prepared - - - -85

Coleus, Leaf and Glands of - - 306

Comparative Anatomy - - - 276

Coniferous Wood from Coal Measures 304

Conn, H. W. , on Louis Pasteur - 17

Cross Stelfe and Retzius Bands, The - 360

Crystallised Silver, Arborescent - 376

Culture Tubes, Inoculating - - 395

Cuticle of Plants, To Prepare - - 385

Cyclops quadricornis - - - 304

Cyclbstoma elegans, Palate of - - 304

Cystopus candidus. Observations on - 225

Cytisus Adami ----- 333

Cytoplasmic Crystalloids of Scilla - 116

Cytotropism of Cleavage Cells - - 91

Dental Enamel, Formation of - - 354

Dermestes lardarius - - - - 383

Desmids ------ 82

Deutzia, Insinerated Leaf of - - 93

Deutzia Scabra, Leaf of - - - 84

Diatomaceous Material, To Treat - 198

Diatomology as an Aid to Geology - 32

Diatoms - - - - - - 192

Diatoms, Artistic Preparations of - 354
Diatoms, Burning on the Platinum

Plate 266

Diatoms, Cement for Fixing on Cover-

g'ass 352

Diatoms, Dry Method of Preparing - 264

Diatoms, Growth of, in Surface Water 100
Diatoms, Monobromide of Napthaline

and Canada Balsam for - - 271
Diatoms, Mounting in Resinous and

Mixed Mediums- - - - 268

Diatoms, Selecting and Mounting - 348

Diatoms, Technology of - - 264, 348

Diatoms, The Pearls of - - - 100

Page

Diatomaceous Material, To Treat - 198
Diatoms, To Spread Uniformly on

Glass ----- 265

Dictynota crassicornis - - - 85

Diplodontus despiciens - - " 3^3

Diptera, The Nervous System of - 280
Distribution of Fungi by Snails and

Toads 354

Distribution of Seeds by the Wind - 148
Dodder and its Host - - 84—86

Dogs 48

Dog- Fish 384

Drawings, Micro- Photographic - - 98

Ducks ------ 50

Durio zibethimus. Leaf of - 84, 86

Eggs of Fowl Parasite - - - 378

Ehrlich's Triple Stain - - - 90
Enamel, Dental, Fibrous Structure of 354

Enamel, Dental, Method of Formation 359
Evolution among Plants, Experimental 8
Examination of Sputa for Tubercle

Bacillus - - - - - 95
Eye of a Fish, Remarkable Structure of 127

Falconer on the Adaptation of Water

Plants to their Environment - - 61

Field, Gleanings from an Old - - 329

Finishing Slides, Remarks on - - 386

Finishing Slides, Varnish for - - 97

Fish, Remarkable Eye-Structure of - 127

Fixing Material, A New - - - 91

Flea, Pygidium of the Common - 227

Flint - - - - - - 133

Flowers, Vestiges of Familiar - - 287

Flowers, The Mysteries of - - 271

Fly 379

Foot of Breeze Fly - - - - 200

Formalin, Tissues Hardened in - - 94
Formation and Structure of Dental

Enamel ----- 355

Formation of Chlorophyll and Starch- 142

Fowls, Eggs of Parasite of - - 378

Fresh-water Diatoms - - - 194

Fresh-water Medusa - - - 222
Fungi, Distribution of, by Snails and

Toads ----- 3^4

Gamasidse, The Family of - - 297

Gelatine and Fish-Glue, Cement - 353

Gelatine, Nutrient - - - - 395

Geology, Diatomology an Aid to - 32

Germination of Oily Seeds - - 156

Gleanings from an Old Field - 45, 329

Good Liquid Cement - - - 191

Growth, Correlation of - - - S3

'^4!7'^t

408

INDEX,

Growth of Trees
Gum-lac Cement

Page

- 60

- 353

Hairs of Larva of Lepidoptera - - 383

Hairs of Tiger-moth Caterpillar - 379
Half-Hours at the Microscope with

Mr. Tuffen West - - - 376
Hardcastle, C. D., On the Origin of

Agates 129

Hardcastle, G. F. , On the New Gases,

Argon and Helium - - - 122
Hardinge, E. M., On Significant Ves-
tiges of Familiar Flowers - - 287
Harrow, W., Limnocodium Sowerbii - 222
Hatching, Peculiar Mode of - - 336
Head and Proboscis of Blow-Fly, Pre-
paring and Mounting - - - 89
Heat of the Sun ... - 102
Heliopelta - . . . . ig-j
Helium and Argon - - - - 122
Hemiptera, The Anatomy of Aphidi-

vorous - - - - - 172

Hexapoda or Insects - - - 279

Holkham, Wild Fowl of - - - 338

Holies' Cliff Diatoms - - - I95
Hoole, C. , and Harrow, W., Notes on

the Victoria Regia - - - 217
Huie, L. H., On Protein Crystalloids
and their Relation to the Nutrition

of the Pollen Tube - - - 113

Human Bone ----- 208

Human Molar, Tr. Sec. of - - 382

Hydrachnidse, British 55, 143, 272, 313

Hydrozoa, The . . - . 278

Improved Borax Carmine Staining

Solution - - - - - 96

Incinerated Leaf of Deutzia - - 93

Inclined Planes for Railways - - loi

Insect Transformation, The Origin of- 57

Insects, Staining Wings of - - 95

Intelligence in Ants - - - 128

Internal Anatomy of Capsus lanarius - 254

Invisible Worlds in Outer Space - 239

I nvisible Worlds, Time, Space, and - 234

Jaspar - . . .
Jersey, Some Slides from -

- 137

- - 388

Lselaps equitans
Lselaps cuneifer
Lselaps Isevis
Larva of Ant-Lion

- 299, 301

- 300

- 300

- 76

Leaf and Glands of Coleus

- 306

Leaf of Alpine Rose

Leaf of Deutzia, Incinerated

- 79

- 93

Page

Leaf of Deutzia scabra - - - 84

Leaf of Durio zibethinus - - 84, 86

Leaves from my Note-Book - 45, 329

Lepidoptera, Hairs of Larva of - 383
Lister, J. J., On the Reproduction of

Orbitolites - - - - 347

Life, Maintenance of, in Low and

High Latitudes - - - 337

Limna^a peregra . . - - 149

Limnocodium Sowerbii - - - 222

Liquid Amber for Diatoms - - 270

Liquid Cement, Good - - - 191

Love, E. G., On Micrometry - - 341

Matches, Cebus and the - - - 16
Membrana praemaformativa. Structure

of 358

Micro-Objects, To find - - - 394

Micro-photo Drawings - - - 98
Micrometry - - - - -341

Microscope, A Remarkable - - 99
Microscope, Half- Hours at the, with

Mr. Tuffen West - - - 376

Microscopical Analysis of Steel - - 93

Microscopical Technique - - 88, 394

Mollusca, Palates of - - - 82
Monobromide of Naphthaline and

Canada Balsam for Diatoms - 271

Moore, R. H., Presidential Address - i

Morris, J. W., On the Bath Waters - 209

Mucilage in Plant-Cells, Detection of - 97

Miiller, H., On Discoveries of Rontgen 187

Myrmecophelous Acari - - - 296

Mysteries of Flowers, The - - 271

Nelson, W., On Limnsea peregra - 149
Nessea longicornis - - - -147
Nessea, The Genus - - - - 143

Neutral Red 90

New Fixing Material - - - 91

New Gases, Argon and Helium, The - 122
New Staining Process - - - 91

Nitrogen, Free, and Non-Leguminous

Plants 102

Note-Book, Leaves from my - 45, 329
Note-Book, P. M.S., Selected Notes

from - - 76, 192, 296, 383

Notes on the Victoria Regia - -217
Nutrient Gelatine . . - . 395
Nutritive Agar, Preparation of Clear - 97
Nutritive Value of Sugar - - - 102

Oamaru Selection - - - 194, 195
Observation on the Structure of Cys-

topus candidus - - - - 225
Oily Seeds, The Germination of - 156

INDEX.

409

Pa^e

Oolite, The Formation of - - - loi

Opal 132

Orbitolites, Reproduction of - - 347

Orchids and Ants ... - 295

Orange, The Bizzaria - - - 334

Orthoptera, Preparing - - ■ 2)i

Outer Space, Invisible Worlds in - 239

Ovaries of Scilla patula, Preparing - 88

Palate of Cyclostoma elegans - - 304
Palates of MoUusca - - ■ - 82
Parasite of Wild Bee - - - 86

Pasteur, Louis - - - - - i?
Peculiar Mode of Hatching - - 336
Peripatus, Myriapods and Insects - 179
Phthisis, Bacilli from - - - 208

Piona ovata ... - - 274
Piona, The Genus - - - - - 273
Plant-Cells, Re-agent for Detection of

Mucilage in - - - "97
Plant, The Spider - - - - 385
Plants, To Prepare Cuticles of - - 233
Plants, Experimental Evolution among 18
Plants, Non-Leguminous - - - 102
Plants, Scentless . . . . ^75
Plums, Sporting in - - - '331
Pleurosigma formosum - - - 194
Potatoes, Sporting in - - - 332

Precious Stones and Rontgen Rays - 224
Predacious and Parasitic Enemies of

Aphides - - 35, 157, 249, 369
Preparation of Clear Nutritive Agar - 97
Preparing & Mounting Head of Blow-fly 89
Preparing Orthoptera - - "33

Preparing the Ovaries of Scilla patula 88
Preservation of Algae - - - 248

Presidential Address - - - i

Proteids of Wheat - - - - 186
Protein Crystalloids in relation to the

Nutrition of the Pollen Tube - 1 13
Pumphrey, W., On Some Slides from

Jersey 388

Pygidium of Flea . . . . 227

Rabbits 47

Rapid Staining - - - - 9.5

Reagent for Detecting Mucilage in

Plant-Cells - - - - 97

Red Stain, Neutral - - - - 90
Remarkable Eye-Structure in a Fish - 127
Remarkable Trees - - - - 178
Reproduction of Orbitolites - - 347
Resinous and Mixed Mediums,

Mountjng in - - - - 268

Resinous Cements for Diatoms - - 353
Retzius Bands and Cross Stelae, The - 360

International Journal of Microscopy
Third Series. Vol. VI.

Page

Rontgen Kays and Precious Stones - 224

Rontgen, The Discovery of - - 187

Root, Mounting .Sections of - - 7°

Root, The Structure of the - - 67

Root, Sectionising - - - - 69

Root, Staining Sections of - - 70

Rose 331

Scales from Wing of Clothes Moth - 380
Scentless Plants - . - - 375

Scilla patula. Preparing the Ovaries of 88
Seeds, Distribution of, by the Wind - 148
Seeds, Germination of Oily - - 156
Selected Notes from P.M.S. Note-
books - - 76, 192, 296, 383
Silica, The Sources of - - -134
Siliceous Nodules, The Origin of - 128
Silver, Arborescent, Crystallised - 376
Skin of Carder Fish - - - - 381
Slides, Remarks on Finishing - - 386
Slides, Varnish for Finishing - - 97
Snails and Toads, Distribution of Fungi

by 354

Soar, C. D., On British Hydrachnidse 55,

143. 272, 313
Sozodont ----- 85, 87
Spatangus - - - - ■ 3^3

Spatangus, Spines of " " - - 376
Spider Plant. The - - - - 233
Sponge Sand - - - - - I95
Sponges . - - . . 388

Sponges, Boring - . - - 204
vSpongilla tluviatilis - - - - 389
Sporting in Plums - - - -331
Sporting in Potatoes - . - 332

Sputum, Examination of, for Tubercle

Bacillus 95

Stain, Ehrlich's Triple - - - 90
Staining Process, New - - - 91
Staining, Rapid - - - "95

Staining .Solution - - - - 7^
Staining Solution, Improved Borax

Carmine - - - - - 96
Staining Wings of Insects - - 95

Stamens of Celsia - - - -78
Starch and Chlorophyll, Function of - 142
Starch-Grains - - - - - 82
Stars, The Binary - - - - 316
Steel, Microscopical Analysis of - 93

Stokes, Alfred C., On the Pygidium of

the Common Flea - - - 227
Storax as a Mounting Medium - 394

Stratum Intermedium, Cells of the - 358
Strawberry Brand - - - - 81

Structure of the Root, The - - 67

.Stylops Spencii - - - 86, 87

AND Natural Science.

BB

410

INDEX.

Page

Styrax for Diatoms - - - - 270

Sugar, Nutritive Value of - - 102

Sun, Heat of the .... 102

SignificantVestiges of Familiar Flowers 287

Technique, Microscopieal - - - 88

Technology of Diatoms - - 264, 348
Tempere, J., On Diatomology as an

Aid to Geology - - - - 32
Tempere, J., On Technology of Dia-
toms .... 264, 348
Thunderstorms and Arctic Hail - 328
Ticks --.... 203
Tiger- Moth Caterpillar, Hairs of - 379
Time, Space, and Invisible Worlds - 234
Tinea vestianella, Scales from Wing of 380
Tingis crassicornis - - - - 85
Tissues Hardened in Formalin - - 94
Toads and Snails, Distribution of

Fungi by 354

Tolu, Balsam of - - . . 270

Top, New, for Educational Purposes - 14

Transformation, The Origin of Insect- 57

Tree, The Burning, of Burmah - - 148

Trees, Remarkable - - - - 178

Trees, The Growth of - - - 60

Triceratium formosum - - - 194

Triple .Stain, Ehrlich's - - - 90
Tubercle Bacillus, Examination of

vSputum for " " ■ ■ 95

Page
Uropoda formicaria; - - - 298, 301
Uropoda canistriana ... - 301
Uropoda coccinia - - - 298, 301
Uropoda lamellosa - - . . 299
Uropodiniae, The Sub-Family of - 297

Varnish for Finishing Slides - - 97
Victoria Regia, Notes on the - - 217
Vine, H. C. A., On Predacious and

Parasitic Enemies of the Aphides 35,

157. 249. 369
Vines 335

Wager, H. T., On Cystopus candidus- 225
Wager, H. T., and Walker, N., On

the Structure of the Root - - 67
Water Plants, Adaptation of, to their

Environment - - - - 61
West, Tuffen, Half-Hours at the

Microscope with - - - 376

Wheat, Proteids of - - - 186

Wild Bee, Parasite of - - - 86
Wild Fowl of Holkham - - - 338
Williams. J. L. , On the Formation and

Structure of Dental Enamel - 354
Wind, Distribution of Seeds by the - 148
Wings of Insects, Staining - - 95

Wyles, H., On Binary Stars - - 316

Zetorchestes micronychus - - - 300

INDEX.

411

IRcviews.

Page
Adulterations, Simple Methods for

Detecting io8

Algebra for Beginners - - - 400
Algebra, The Intermediate - - 310
Animal World, The - - - 215

Apochrypha, The . . - - 109
Aquarium, The ... - 309

Astronomers, Great - - - - 106
Astronomy, A Popular Handbook and

Atlas to 310

Atlas, The Unrivalled - - - 214

Bacteria, Text-book of Pathogenic

Band of Mercy, The

Battles of the 19th Century 112, 312,

Bible, The Mite - . - -

Biological Problem of To-day -

Biology, Text-book of Elementary

Bird-Song, The Evolution of

Birds, A Manual of North- American -

Birds, Chats about British

Birds of Great Britain, Handbook to

the 103,

Book of the Fair, The - - 215,
Botany Sheets for Beginners
Boy Skipper, The . . - -
British and Colonial Druggist Diary -
British Battles - - - - 112,
British Butterflies . . - .
Buddha, The Gospel of - - -
Butterflies and Moths, British and

European - - - - -
Butterflies and Moths, European 1 1 1 ,
By the Deep Sea . . - -

Cassell & Co.'s Publications
Cassell's Concise Cyclopredia
Cassell's Natural History
Cat, The

Chemist and Druggist's Diary
Chemistry, Organic, Lessons in
Chess Endings, Analysis of
Chums

307
215
403
215

399
213
308
398
308

308

403
398
no
109
312
398
311

104
104
399

216
404
404
402
no

399

214

112, 312, 404

312,
312,

Coal, The Story of a Piece of - - 311
Cookery and Pastry, The Practice of - 312
Cycling, Pleasure - - - - 312

Die Naturlichen Pflanzenfamilien

215,
Down the Village Street
Dynamics, A Text-book of

Earth, The Story of, in Past Ages

Earth Knowledge

Eclipses, Historical and Future

Electricity for Students

Electricity, The Story of -

Encyclopiedia, The Oracle iii, 310, 403

" - 3"

- 112

- 214

- 312

Page

- 104,

308, 397

- 109

- 212

106

399
310
106
311

English Lakes, Black's Guide to
English Specialist's Journal
Euclid, Common-sense
European Butterflies and Moths

Devonshire, The Way about
Dictionary, A New English

- 400

- no, 214,

310, 400

Ferns, British and Foreign - - 105

Flowering Plants, Analytical Key to

the Natural Orders of - - 105

Food and Drugs, Aids to the Analysis

of 104

Fungi, Introduction to the Study of - 104

French Grammar, The Tutorial - 214

Game Birds, Handbook of - - 213

Gardening, Beeton's Dictionary of - 215
Geography, Skeitchley's New Physical 400
Golden Thoughts from the Book of

Spiritual Poverty - - - 403

Golden Thoughts on the Higher Life - 403
Gospel of Buddha - - - ■ SH
Grasses, Handbook of - - - 105
Great Yarmouth, Illustrated Guide to - 109

Hazell's Annual - - - - in

Health and Beauty, Helps to - - 108
Health. The Ritual of - - - 397

Heat, An Elementary Treatise on 107

ni, 312, 404
- 397

Heavens, The Story of the
Histology, A Text-book of

Industrial Explorations - - - 107
Insects and Spiders - - - - 399
Insects, Some Common, and other

Lowly Forms . - . . 103
Intensity Coils .... 401

Intermediate Algebra, The - - 310
Intermediate Science - - - 309

John Ploughman's Pictures - - 402

412

INDEX

Page
Lantern and how to use it - - 107

Le Cure du Benizou - - - - 109

Lepidoptera, British, Handbook to - 104
Lepidoptera, Handbook to - - 308

Little Folks 112

Lyell, Charles, and Modern Geology - 106

Magic Lantern, The - - - 401

Man, Origin and Nature of - - 109
Mankind, A History of - - - 398
Mathematical Questions and Solutions 309
Mechanics, First Stage - - - 107
Medical Annual, The - - - 213

Memory and the Specific Energies of

the Nervous System - - - no
Memory Maps, Arnold's - - - 108

Microscope, A Popular Handbook to

the 103

Microscopy, Modern - - - - 103
Microscopy, Practical Methods in - 212
Moths, British 213

Natural Science, The Elements of - 104

Nature, The Forces of - - - 107

Nature, The Hidden Beauties of - 103

Nature's Bypaths . . . . ^09

Nature's Story .... 103

Nature's Wonders - . . - 309

Norway, New Ground in - - - 400

Optical Instruments, Modern - - 401
Oracle Encyclopedia, The - 310, 403

Our Country Butterflies and Moths - 308

Pathogenic Bacteria, Text-book of - 307
Photographer, The Junior - - 402

Photographer, The Practical - - 402
Photographic Annual, 1896 - - 401

Photographic Reference Book - - 311
Photography, ABC of Modern Dry-
Plate - - - 216, 402
Photography, American Annual of - 213
Photography, Beginner's Guide to - 402
Photography, Drop-Shutter - - 402
Photography, .The Elements of Stereo-
scopic ----- 402
Photography, The New - - - 216
Photography. Year-Book of - - 31 1
Physical Laboratory Manual - - 212

Page
Physics, A Laboratory Course of

Experimental - - - - 212

Physics, A Manual of - - - 107

Physiology - - - - - 108

Plants : How they Live and Work - 307

Pleasure-Cycling - - - - 312

Prayer-Book, Tlie Oxford Thumb - 214

Puzzles, Everybody's Book of - - no

Queen Victoria's Dolls

no

Random Recollections of Woodland,

Fen, and Hill - - - - 105
Rheumatoid Anthritis - - - 397

Romance of Industry and Invention - 400
Rose-Bud Annual, The - - - 109
Royal Natural History, The - ni, 216,

309. 403

Science for All - - n2, 312, 404

Science, The Intermediate - - 309

Science, Popular Readings in - - 106

Science Progress - - - - in

Seaweeds, Intro, to the Study of - 105

Seedlings, A Contribution to our

Knowledge of - - - - 213

Skertchley's Physical Geography - 400

Solar System, The Story of - - 213

Splash of a Drop The - - - 106
Stamps, Bright's ABC Catalogue of - 216

Stamps, British, Catalogue of - - 112

Stars, Half-Hours with the - - 105

Story of a Piece of Coal - - -311

Story of Electricity - - - - 311

Story of the Heavens - - - 312

Tallerman, Sheffield, Pal. Hot-Air Bath 1 10
Taxidermy and Modelling, Artistic - 309
Testament, The Midget - - - 215

Universal Medical Science Annual

108

Vegetable Pharmacognosy, Essentials of 212

Wayside and Woodland Blossoms - 307
Wild Flowers, How to Study - - 398
Will, The Diseases of the - - 109
Work 403

Zoo, The -

106

END OF VOLUME VI.

T^-^ <^r.-..-iv.^,\:.-ii

;:^