Transcriber’s notes:
Minor punctuation errors have been corrected silently (e.g. missing
full stops after abbreviated words such as Fig), as have the following
misspellings: Bretahing → Breathing, Pedicillaria → Pedicellaria,
Pedicelaria → Pedicellaria, Chœtonotus → Chætonotus, Spurganium
→ Sparganium, veiw → view. Unorthodox spelling and inconsistent
hyphenation has not been altered. Several wrongly numbered
cross-references to Plates and Figures have been corrected.
Plate VIII (and its accompanying key) was originally displayed
at the beginning of the book, before the Title Page, but has been
repositioned in the body of the text in correct numerical sequence.
COMMON OBJECTS OF
THE MICROSCOPE
BY THE LATE
Rev. J. G. WOOD, M.A., F.L.S., Etc.
AUTHOR OF
“COMMON OBJECTS OF THE COUNTRY” “COMMON OBJECTS OF THE SEA-SHORE”
“MY FEATHERED FRIENDS” ETC. ETC.
WITH ILLUSTRATIONS BY TUFFEN WEST
_SECOND EDITION, REVISED AND RE-WRITTEN, BY_
E. C. BOUSFIELD, L.R.C.P.(Lond.)
AUTHOR OF
“A GUIDE TO THE SCIENCE OF PHOTO-MICROGRAPHY”
WITH ADDITIONAL ILLUSTRATIONS BY THE REVISER
LONDON
GEORGE ROUTLEDGE AND SONS, Limited
BROADWAY HOUSE, LUDGATE HILL
1900
PREFACE TO THE SECOND EDITION
The task of revising and bringing up to date a work which has been the
guide, philosopher, and friend of thousands of commencing microscopists
has been, in the present case, one of no small difficulty. On the one
hand, there was the natural desire to interfere as little as possible
with the original work; and on the other, the necessity of rendering
available, to some extent at least, the enormous advance in every
department which has taken place in the thirty-six years which have
elapsed since the work was first offered to the public. The reviser has
done his best not only to fulfil these two objects, but to keep in view
the original purpose of the book.
In the popular department of pond-life especially, about fifty new
illustrations have been added, mostly from the reviser’s own notebook
sketches. The whole of the botanical part has been revised by one of
our first English authorities, and, in short, no effort has been spared
to make the work as accurate as its necessarily condensed form permits
of. It is hoped, therefore, that it may be found not less useful than
its predecessor by those for whom it is alone intended.
PREFACE TO THE FIRST EDITION
In my two previous handbooks, the “Common Objects” of the Sea-shore and
Country, I could but slightly glance at the minute beings which swarm
in every locality, or at the wonderful structures which are discovered
by the Microscope within or upon the creatures therein described. Since
that time a general demand has arisen for an elementary handbook upon
the Microscope and its practical appliance to the study of nature, and
in order to supply that want this little volume has been produced.
I must warn the reader that he is not to expect a work that will figure
and describe every object which may be found on the sea-shore or in the
fields, but merely one by which he will be enabled to guide himself
in microscopical research, and avoid the loss of time and patience
which is almost invariably the lot of the novice in these interesting
studies. Upwards of four hundred objects have been figured, including
many representatives of the animal, vegetable, and, mineral kingdoms,
and among them the reader will find types sufficient for his early
guidance.
Neither must he expect that any drawings can fully render the lovely
structures which are revealed by the microscope. Their form can be
given faithfully enough, and their colour can be indicated; but no pen,
pencil, or brush, however skilfully wielded, can reproduce the soft,
glowing radiance, the delicate pearly translucency, or the flashing
effulgence of living and ever-changing light with which God wills to
imbue even the smallest of His creatures, whose very existence has been
hidden for countless ages from the inquisitive research of man, and
whose wondrous beauty astonishes and delights the eye, and fills the
heart with awe and adoration.
Owing to the many claims on my time, I left the selection of the
objects to Mr. Tuffen West, who employed the greater part of a year
in collecting specimens for the express purpose, and whose well-known
fidelity and wide experience are the best guarantees that can be
offered to the public. To him I also owe many thanks for his kind
revision of the proof-sheets. My thanks are also due to Messrs. G. and
H. Brady, who lent many beautiful objects, and to Messrs. Baker, the
well-known opticians of Holborn, who liberally placed their whole stock
of slides and instruments at my disposal.
CONTENTS
CHAPTER I PAGE
Pleasures and Uses of Microscopy--Development of the
Microscope--Extemporised Apparatus 1
CHAPTER II
Elementary Principles of Optics--Simple Microscopes--Compound
Microscope--Accessory Apparatus--Cover-glasses--Troughs--
Condensers--Dissection--Dipping-tubes--Drawing--Measurement 7
CHAPTER III
Examination of Objects--Principles of Illumination--Mirror
and its Action--Substage Condenser--Use of Bull’s-eye--Opaque
Objects--Photography of Microscopic Objects 28
CHAPTER IV
Vegetable Cells and their Structure--Stellate Tissues--
Secondary Deposit--Ducts and Vessels--Wood-Cells--Stomata,
or Mouths of Plants--The Camera Lucida, and Mode of Using--
Spiral and Ringed Vessels--Hairs of Plants--Resins, Scents,
and Oils--Bark Cells 37
CHAPTER V
Starch, its Growth and Properties--Surface Cells of Petals--
Pollen and its Functions--Seeds 63
CHAPTER VI
Algæ and their Growth--Desmidiaceæ, where found--Diatoms,
their Flinty Deposit--Volvox--Mould, Blight, and Mildew--
Mosses and Ferns--Mare’s-Tail and the Spores--Common
Sea-weeds and their Growth 78
CHAPTER VII
Antennæ, their Structure and Use--Eyes, Compound and
Simple--Breathing Organs--Jaws and their Appendages--Legs,
Feet, and Suckers--Digestive Organs--Wings, Scales, and
Hairs--Eggs of Insects--Hair, Wool, Linen, Silk, and
Cotton--Scales of Fish--Feathers--Skin and its Structure--
Epithelium--Nails, Bone, and Teeth--Blood Corpuscles and
Circulation--Elastic Tissues--Muscle and Nerve 96
CHAPTER VIII
Pond-Life--Apparatus and Instructions for Collecting
Objects--Methods of Examination--Sponge--Infusoria 132
CHAPTER IX
Fresh-water Worms--Planarians--Hydra--Polyzoa--Rotifers
Chætonotus--Water-Bears 144
CHAPTER X
Marine Life--Sponges--Infusoria--Foraminifera--Radiolaria--
Hydroid Zoophytes--Polyzoa--Worms--Lingual Ribbons and
Gills of Mollusca--Star-Fishes and Sea-Urchins--Cuttle-Fish--
Corallines--Miscellaneous Objects 154
CHAPTER XI
Hints on the Preparation of Objects--Preservative Fluids--
Mounting Media--Treatment of Special Objects 168
CHAPTER XII
Section-Cutting--Staining 179
COMMON OBJECTS OF THE MICROSCOPE
CHAPTER I
Pleasures and Uses of Microscopy--Development of the
Microscope--Extemporised Apparatus.
Within the last half-century the use of the microscope, not only as
an instrument of scientific research, a tool in the hands of the
investigator of the finer organisation of the world of nature, nor even
as an adjunct to the apparatus of the chemist or the manufacturer, but
as a means of innocent and instructive recreation, has become so firmly
rooted amongst us that it seems hardly necessary to advocate its claims
to attention on any of these grounds.
So wonderful is the information which it affords, so indispensable is
it in many, if not in all, branches of scientific research, that not
only would the lover of nature be deprived of one of his most valued
sources of information and enjoyment, but some sciences would be
brought absolutely to a standstill if by any conceivable means the
microscope were to be withdrawn from their followers.
On the other hand, from every improvement in the construction of the
latter, a corresponding enlargement and enlightenment of the fields
reviewed by these sciences has taken place, and the beauty and interest
of the revelations made by its means has attracted an ever-increasing
host of earnest and intelligent volunteers, who have rendered yeoman
service to the cause of knowledge.
Moreover, so vast is the scope of the instrument, that whilst
discoveries in other fields of research are few and far between,
comparatively speaking, in microscopic science they are of everyday
occurrence, and the number of problems calling for solution by means of
the instrument in question is so vast that even the humblest worker may
be of the greatest assistance.
In the following pages we propose to carry out, as far as possible
with reference to the microscope, the system followed in the “Common
Objects of the Seashore and of the Country,” and to treat in as simple
a manner as may be of the marvellous structures which are found so
profusely in our fields, woods, streams, shores, and gardens. Moreover,
our observations will be restricted to an instrument of such a class as
to be inexpensively purchased and easily handled, and to those pieces
of supplementary apparatus which can be extemporised at small cost
of money and ingenuity by the observer himself, or obtained of the
opticians for a few shillings.
With the same view, the descriptions will be given in language as
simple and as free from technicalities as possible, though it must
be remembered that for many of the organisms and structures which we
shall have to describe there are none but scientific names; and since,
moreover, this little work is intended to furnish a stepping-stone
between the very elements of microscopic science, and those higher
developments of it which should be the aim of every worker, it would be
unwise to attempt to invent commonplace appellations for the purpose of
this book, and leave him to discover, when he came to consult works of
reference in any particular subject, that his “simplified” knowledge
had all to be unlearnt, and a new vocabulary acquired. Rather will
it be our purpose to use correct terms, and explain them, as far as
necessary, as we introduce them.
The commencing microscopist is strongly recommended, whilst not
confining his interest entirely to one branch of research or
observation, to adopt some one as his particular province.
The opportunities for discovery and original work, which are afforded
by all alike, will be more readily appreciated and utilised by
adopting such a plan than by a general and purposeless distribution of
effort. To mention one or two. The student of the fascinating field of
pond-life will find new organisms awaiting description by the hundred,
and of the old ones, life-histories to make out; if he be attracted
rather to the vegetable inhabitants of the same realm, the diatoms will
furnish him with the opportunity of studying, and perhaps solving,
the enigma of their spontaneous movement, and of watching their
development. The smaller fungi, and indeed the larger ones too, will
amply repay the closest and most laborious study of their habits of
life and processes of development. Since the first edition of this work
was published, the whole subject has been practically revolutionised,
and more remains to be done than has yet been accomplished.
In short, there is scarcely an organism, even of those best known
and most studied, which is so completely exhausted that persevering
investigation would reveal nothing new concerning it.
There can be little doubt but that if any worker, with moderate
instrumental means, but with an observant mind, were to set
determinately to work at the study of the commonest weed or the most
familiar insect, he, or she, would by patient labour accomplish work
which would not only be of value to science, but would redound to the
credit of the worker.
Something like finality appears to have been reached, at least for the
present, in the development of the microscope; and whilst it is beyond
the scope of this work to treat of the refined and costly apparatus
which is essential to useful work in certain departments of research,
the result has, on the whole, been highly favourable to the worker of
moderate means and ambitions, since lenses are now accessible, at the
cost of a few shillings, comparatively speaking, which could not have
been purchased at all when this work first appeared. It is with such
appliances that we have here to deal. The worker whose finances are
restricted must be contented to extemporise for himself many pieces
of apparatus, and will find pleasure and occupation in doing so. And
let him remember, for his encouragement, that many such home-made
appliances will fulfil their purpose quite as well as the imposing
paraphernalia of glittering brass and glass which decorates the table
of the wealthy amateur. It is not the man who possesses the best or
most costly apparatus, but the one who best understands the use of that
which he possesses, that will make the most successful microscopist. A
good observer will discover, with only the aid of a pocket-magnifier,
secrets of Nature which have escaped the notice of a whole army of
dilettante microscopists, in spite of the advantages which, as regards
instruments, the latter may enjoy.
It is for those who desire to be of the former class that this book
is written, and in the course of the following pages instances will
be given in which the exercise of a small amount of ingenuity and the
expenditure of a few pence will be found equivalent to the purchase of
costly and complicated apparatus.
An enormous amount of valuable work was done in the earliest days
of microscopy, when the best apparatus available was a single lens,
composed of the bead formed by fusing the drawn-out end of a rod
of glass. Inserted into a plate of metal, or a piece of card, such
a primitive instrument was capable of affording a large amount of
information. Similar instruments are to be purchased for a few pence
at the present day, and are not without their use for purposes of
immediate examination of material. A very common form is a glass
marble, ground flat on one side, and mounted in a tube. The material to
be examined is placed upon the flat side, and is seen magnified to an
extent inversely proportional to the diameter of the sphere of glass.