[Transcriber's Notes
Emphasis is denotes as _Italic_ and =Bold=. Most small caps text
has been converted to ALL CAPS; but where some may have been
rendered as Mixed Case letters where it seemed appropriate.]
[Illustration: FIG. 1.--THE SCALLOP SHELL, _Pecten Opercularis_ (see
page 107), SLIGHTLY REDUCED IN SIZE. THE LARGER SHELLS ARE FROM DOUGLAS,
ISLE OF MAN; THE SMALLER SHELLS ARE YOUNG SPECIMENS FROM LLANDUDNO,
NORTH WALES.]
STORIES _of the_ UNIVERSE
Animal Life
By
B. LINDSAY
_WITH FORTY-SEVEN ILLUSTRATIONS_
NEW YORK
REVIEW _of_ REVIEWS COMPANY
1909
COPYRIGHT, 1902
BY D. APPLETON AND COMPANY
_All rights reserved_
PREFACE
Of the diagrams which illustrate this little volume, the majority were
prepared by Miss E. C. Abbott (formerly Bathurst Scholar at Newnham
College, Cambridge): the sketches were made from specimens in the South
Kensington Museum of Natural History, which has kindly granted
permission for their use. In addition to these, there are several
figures that are taken from specimens in my possession, photographed by
the publishers; two or three cuts are diagrammatic; and I owe to the
kindness of Mr. J. Craggs, formerly president of the Northumberland
Microscopical Association, the drawings of Polycystina and of the scales
of the Sole.
B. L.
CONTENTS
CHAPTER PAGE
I. THE STORY OF ANIMAL LIFE 9
II. HOW ANIMALS ADAPT THEMSELVES TO CIRCUMSTANCES 13
III. CLASSIFICATION: THE SORTING OF THE ANIMAL KINGDOM 30
IV. THE ONE-CELLED ANIMALS, OR PROTOZOA 45
V. THE COELENTERATA 53
VI. THE SPONGES 63
VII. THE VERMES OR WORMS 68
VIII. THE ARTHROPODA: LOBSTERS, SPIDERS, AND INSECTS 76
IX. THE MOLLUSCA, OR SHELL-FISH 98
X. THE BRACHIOPODA, OR LAMP-SHELLS 117
XI. THE MOSS-CORALS, OR POLYZOA 119
XII. THE ECHINODERMATA 122
XIII. THE CHORDATA 135
XIV. THE VERTEBRATA 138
XV. MAN 167
XVI. HOW ZOOLOGISTS DO THEIR WORK 180
INDEX 193
LIST OF ILLUSTRATIONS
FIGURE PAGE
1. The Scallop-Shell _Frontispiece_
2. Limpets and Periwinkles 19
3. Diagram of _Amoeba_ 35
4. Section of _Hydra_ 36
5. Diagrammatic Section of Earthworm 38
6. Diagram of a Gastrula 41
7. Diagram of a Trochosphere 42
8. Shells of Radiolarians (Polycystina) 47
9. A Coralline 58
10. Gorgonia 59
11. Corals 60
12. Marine Worms 73
13. A Centipede 77
14, 15. Shells of Barnacles 79, 80
16. Hermit Crabs 81
17. A Land Crab 82
18. A Sand-hopper 83
19. A Spider 84
20. Nest of Trap-door Spider 85
21. _Galeodes_ 86
22. A Tick 87
23. A Scorpion 88
24. Larvæ of Insects 90
25. Larva of the Bee 92
26. Ants 92
27. White Ants 93
28. Cocoons of Moths 94
29. A Moth and its Larva 95
30. Nest of a Gregarious Caterpillar 96
31. Development of an English Water-beetle (_Dytiscus_) 96
32. Insect Pests 97
33. Branchy Murex 102
34. Shell of the Common _Venus_ 104
35. Eggs of Molluscs 115
36. The Five-holed Sand-Cake 125
37. A Brittle-Star 129
38. A Sea-Cucumber 130
39. A Stone-Lily or Encrinite 131
40. A Feather-Star 132
41. Sections showing Position of the Vertebrate Notochord 139
42. Scales of a Sole 143
43. Tadpoles 153
44. Eggs of Reptiles 155
45. Skull of Kangaroo 162
46. Skull of Rodent 163
47. Slide with Rows of Sections for the Microscope 185
THE STORY OF ANIMAL LIFE
CHAPTER I
THE STORY OF ANIMAL LIFE
If the microscope had never been invented, the Story of Animal Life, as
it is related by modern science, could never have been told. It is to
the microscope that we owe our knowledge of innumerable little animals
that are too small to be seen by the unassisted eye; and it is to the
microscope that we owe the most important part of our knowledge about
the bodies of larger animals, about the way in which they are built up,
and the uses of their different parts. The earlier opticians who toiled,
one after another, to bring the microscope to perfection, never dreamed,
in their most ambitious moments, of the value of the gift that their
labour was to confer upon mankind. For the microscope alone has made it
possible for men of science to study the world of living things. This is
the value of honest and thorough work in almost every department of
intellectual labour; that it builds a firm and sure though perhaps
hidden foundation for the loftier and more perfect work of after days.
The microscope has shown us the intimate structure of every organ of
the animal body; and thus, in most cases, the uses of the organ, and
the steps by which it performs its tasks, have been made clear. The
microscope has also shown the true nature of the sexual functions, and
all the steps of the processes of growth in young animals. None of these
things could ever have been rightly understood without the microscope,
for all their most important details are invisible to the naked eye.
To the microscope, too, we owe our knowledge of the essential kinship
between plants and animals; to it, also, our understanding of the
oneness, the "solidarity," as the French would say, of the animal
kingdom, for it is in the structure of microscopic parts that
resemblances are revealed under the most strikingly different
circumstances of outward form.
Let us inquire a little into the history of the animals that can only
be seen by the aid of the microscope. Most of them live in water,
especially dirty water, containing decaying remains of plants or
animals. The naturalists who first discovered them studied them in
"infusions" of hay, and so on, and hence these little creatures were
named Infusoria--a name that has since been somewhat restricted in its
application. By an "infusion" is meant that water is poured on some
substance and allowed to stand; the more ancient and evil-smelling the
infusion becomes, the more of these little animals do you find living in
it. Nature provides dirty water ready made, in ditches and in ponds, and
these are full of microscopic animals. And not only do they appear in
dirty water, but kindred kinds appear in clean water also, and many in
the waters of the sea.
It will easily be understood that when the existence of microscopic
animals was discovered, zoologists had greatly to modify their ideas of
the animal world. Still more was this the case afterwards, when it was
found that all animals were built up of minute parts much resembling
these microscopic animals in their main features. To these unit parts,
of which all animal bodies are composed, the term "cell" is applied.
The name of cell is not very descriptive of these units in the animal
body, but correctly describes the unit of plant structure. In certain
important essential particulars both, however, are alike. Nowadays we
are not content to describe the grouping and external features of cells;
their minute structure also is made a subject of research and inquiry,
and affords a field for most of the fashionable speculations of our own
day.
How great has been the progress made by the science of zoology since the
eighteenth century may be estimated from the following quotation:--
"I remember," says the late George J. Romanes (in his book called "The
Scientific Evidences of Organic Evolution"), "once reading a very
comical disquisition in one of Buffon's works on the question as to
whether or not a crocodile was to be classified as an insect; and the
instructive feature in the disquisition was this, that although a
crocodile differs from an insect as regards every conceivable particular
of its internal anatomy, no allusion at all is made to this fact, while
the whole discussion is made to turn on the hardness of the external
casing of a crocodile resembling the hardness of the external casing
of a beetle; and when at last Buffon decides that, on the whole, a
crocodile had better not be classified as an insect, the only reason
given is, that as a crocodile is so very large an animal it would make
'altogether too terrible an insect.'"
How different is the state of knowledge now, when every part of a
crocodile or a cockroach is described in print in the minutest detail,
and set before even the beginner in zoology as a necessary lesson.
But in spite of the labour necessary to master such detailed lessons,
the study of the animal world is far from prosaic. The Story of Animal
Life, indeed, bids fair to be the only element of romance left in the
modern world for those who stay at home in their own land. The traveller
of days of yore, when he ventured into the woods and fields, or upon
the water, expected to meet with all sorts of strange things--fairies
and elves and ugly gnomes; giants, ogres, and dragons; mermaids and
water-witches. With the spread of education all these things have
vanished now; it is quite certain that no Board-School-boy has ever met
any of them: and one's walks abroad would be in these days as prosaic as
they are safe, but for the world of animal life. If you have eyes for
this, every field has its inhabitants, and every hedge its marvels.
Instead of a fairy, you may be well contented to meet a dragon-fly with
shining wings; instead of an ogre you will find the fierce spider, which
not only makes away with every harmless fly that blunders into her net,
but in many cases destroys her own kind also. Many a plant may be met
with which has its own special caterpillar or other dependent insect,
with ways of its own, which may amuse your idle hours. As for the change
of a caterpillar or a tadpole into its adult form, it would be taken for
a miracle if it were observed for the first time.
The reader may have noticed that there are some unfortunate people who
have no eyes for these things; from childhood upwards they have been so
absorbed in money-making or in reading books--the one case is as bad as
the other--that they have never learnt to observe the facts of nature.
Some cannot even recognise the different kinds of plants that they see
in the hedges, or in a country walk. Such natures are intellectually
defective; they are much to be pitied, and require a special training to
remedy their stupidity. I mention this, because the occurrence of this
form of stupidity is one of the dangers resulting from town life and
bookish education, which we have to guard against at the present time.
But for all healthy people accustomed to the outdoor world, the study of
animal life has always possessed an interest. Its interest has, however,
been increased a hundred fold by the progress of modern discovery, which
has taught us to see in the animal kingdom one large family, working its
way upwards from humble beginnings, to more perfect structure of body,
and more complete intelligence of mind.