FIRST BOOK
OF
Z O  0 L O                                                    G Yo
BY
EDWARD S. MORSE, PH. D.,
LATE PROFESSOR OF COMPARATIVE ANATOMY AND ZOOLOGY IN BOWDOIN COLLEGE.' As for your pretty little seed-cups, or vases, they are a sweet confirmation of the pleasure
Nature seems to take in superadding an elegance of form to most of her works, wherever you
find them. How poor and bungling are all the imitations of art! When I have the pleasure
of seeing you next we will sit down-nay, kneel down if you will-and admire these things."
-[HOGARTI in, a Letter to ELLIS.




ENTERED, according to Act of Congress, in the year 1875, by
D. APPLETON & COMPANY,
In the Office of the Librarian of Congress, at Washington.




PRE FACE.
THEI ":First Book of Zo6logy" is expressly prepared
for the use of pupils who wish to gain a general knowledge of the structure, habits, modes of growth, and other
leading features concerning the common animals of the
country.
Particular attention has been given to the lower animals,
as these are more often neglected in text-books. Directions
for collecting, the preparation of specimens for the cabinet,
and the haunts of the animals to be studied are given, and
the pupil is expected to study, with the book in one hand,
and the specimens in the other. The figures illustrating this
worl, with a few exceptions, have been drawn from Nature
by the author, and have been prepared with especial reference to their being copied by the pupil. Tc facilitate this
the figures are made in outline, with the shaded side of the
figure indicated by darker lines.




;sT~                    PREFACE.
The necessity of the pupils copying (however poorly) the
figures, either upon the slate, or upon paper, cannot be too
strongly urged.
From his own experience, the author has learned that a
specimen or figure may oftentimes be carefully studied, and
yet only an imperfect idea be formed of it; but, when it
had been once copied, the new points gained repaid all the
trouble spent in the task.
It makes but little difference whether the pupil is proficient in drawing or not; it should be strenuously insisted
upon by the teacher that the pupils copy, as far as possible,
the figures contained in each lesson.
To collect in the field, to make a cabinet, and then to examine and study the specimens collected, are the three stages
that naturalists, with few exceptions, have passed through in
their boyhood.
If one recalls the way in which boys first manifest their
taste for such studies, he will remember that first a few examples were brought together; a collection was made.  It
may have been birds'-eggs, insects, or shells; then little
boxes, a case of drawers, or shelves, were secured to hold
their treasures.  In thus collecting and arranging and rearranging the cabinet, the eye becomes familiar with the outline and general character of the objects, and in this way the
mind is finally prepared to comprehend the relations existing




PREFACE.                       V
between animals, and to appreciate the leading points upon
which classification is founded.
Agassiz invariably placed before his students a single
specimen, or a box full of specimens, and told them to look
and see what they could find out.
It has seemed, therefore, that the way to commence the
study of zoology is to follow the course one naturally pursues
when he is led to the study by predisposition. Nor is it essential, at the outset, to present the entire range of the animal kingdom. Teach the characters of one or two great divisions first, and then the pupil is better prepared to grasp in
turn the other divisions.  The persistent attempt, in all textbooks of this kind, to give some attention to every large
group in the animal kingdom, has often resulted in wearying
and confusing the minds of those who take up the study for
the first time.
A very serious difficulty is encountered in those books
which give a more or less complete view of systematic zoology. for beginners. In some, the authors commence with
the lowest forms, and end with the highest. ID others, the
highest animals are dealt with first, and the lessons end with
the lowest.  The first mistake made is the attempt to
teach systematic zoology, where the pupil is quite ignorant
of the material to be classified; and proper familiarity
with the objects, the author contends, can only be acquired




vi                      PREFACE.
by collecting the specimens and forming a little cabinet of
them.
The difficulty, however, arises in commencing the lessons with either the lowest or the highest animals. If the author commences with the lowest animals, he deals at the outset with creatures which the pupil in certain cases can never
see, as many of the animals to be considered are microscopic,
and most of them  of such a nature that their soft parts
cannot be preserved.  On the other hand, if the author commence with the vertebrates, he presents, point-blank, some
of the forms of structure most difficult to understand.
The main thing at the outset is to teach the pupil how
to collect the objects for study; this leads him to observe
them in Nature, and here the best part of the lesson is
learned: methods of protection for the young, curious
habits, modes of fabricating nests, and many little features
are here observed, which carl never be studied from  an ordinary collection. Hence, collecting in the field is of paramount imlportance. Next, the forming of a little collection
at home prompts the pupil to seek out certain resemblances
among his objects, in order to bring those of a kind together.
In this way he is prepared to understand and appreciate
methods of classification. Finally, having grasped the leading features of a few groups, he is enabled to comprehend
the character of cognate groups with less difficulty.  Thus,




PREFACE.                      vii
an inland student, having got the typical idea of an insect
from the study of a common grasshopper, for example, is
much better prepared to understand the general structure
of the Crustacea, though he may never have seen the few
forms peculiar to fresh water.  In the same way after
having studied the common earthworm, he can form  a
better idea of the complicated structure of many marine
worms, though these he may never see. After long deliberation, and some hesitancy, the author is forced to depart
from  common usage, and present, in this first book, only a
few of the leading groups in the animal kingdom.
From  the abundance of material, and the comparative
ease with which the specimens may be preserved for cabinet
use, shells and insects have always formed the favorite collections of children.  They are the most commona objects in
nearly all collections, and it has seemed to the author that
here the pupil ought to commence his studies.
Having learned to collect and prepare specimens for the
cabinet, and to observe the relations and differences existing
among them, the pupil is then prepared to go on to forms
less familiar, or to study in detail the material already gone
over.
Great pains have been taken to present, in every case,
drawings made from  the animal, expressly for this book.
They are all American, and, with few exceptions, are en



viii                   PREFACE.
tirely new. It is believed that teachers will appreciate the
absence of those hackneyed illustrations which have too long
done service in text-books on the subject.
To those especially interested in the study, many figures
are given which have never before been published, even in
scientific work]s, as, for example, the rare 1ymnacea mnegasoma, Lymnzca anmpla, Ptyelus lineatus, and many others.
I desire here to express my thanks to Dr. A. S. Packard,
for looking over the pages relating to insects, and to Dr. I-I.
Hagen, Mr. Samuel HI. Scudder, Prof. H. H. Straight, Prof.
Theodore Gill, Prof. A. JO Cook, and lMiss Maggie W.
Brooks, for important specimens for illustration; and to the
firm of Russell & Richardson, Boston, who, with the interest
of personal friends, have attended to the proper engraving
of my drawings. I am also deeply indebted to Prof. E. L.
Youmans, Mr. John M1. Gould, and MIr. Henry W. Swasey,
for valuable suggestions and advice; and, finally, I have to
express my gratitude to the publishers of this book, who
have, with unbounded liberality, left the entire matter of
illustration in my hands.
Eo S. M.
SALEAM, MASS., Mfarch 12, 1875.




CONTENTS.
CHAPTER I.
PAGE
FRESH-WATER SHELLS...
Where to collect, 1; Empty or Dead Shells, 2; Parts of a Shell named, 8; Forms of
Spire, Dextral, and Sinistral Shells, 4; Lines of Growth, Growth of a Shell, 5, 6.
CHAPTER II.
FRESH-WATER SNAILS..... 
Where and how to collect, 7, 8; Live Shells, 8; Head, Tentacles, Foot, how they
breathe, 9, 10; Operculum, 12; Gills, 13.
CHAPTER III.
LAND SNAILS.......  14
Where to collect, 14; Parts of the Animal, 15, 16; Tentacles, Jaw, 17; Explanation
about an Object being enlarged, 18; Slug, 19; Eggs and Young, 20; Mantle, 21.
CHAPTER IV.
SEA SNAILS.........  21
Where to collect, 22; Entire Aperture, Aperture Notched or Canaliculated, 23; Siphon, and its Uses, 24; Flesh and Animal Feeders, 25; Egg-cases or Capsules,
26, 27.
CHAPTER V.
FRESH-WATER MUSSELS                                                               27
Where found, 27; Ligament, Lines of Growth, 28; Regions of Mussel, 29; How
they crawl, 30; Excurrent and Incurrent Orifices, 31; Siphons. Mantle, 32; How
Pearls are formed, 83; Internal Markings of Shell, Hinge, 84; HIow the Shells
open and Ligament acts, 36.




X                                   CONTENTS.
CHAPTER VI.
PAGE
CLAMS, MUSSELS, AND OYSTERS....                          37
Salt-water Bivalves, 37; Parts of a Clam, Siphons, Currents of Water, and how
they eat, 38, 89; Ligament, and Internal Markings of Shell, 40; Byssus, 42;
Siphonal Tubes separate, 44; Oysters, 45; Heart, Palpi, Liver, Gills, Mouth of
Oyster, 46, 47; Relations between Clamus, Mussels, and Snails, 48.
CHAPTER VII.
COLLECTING INSECTS........  49
HIow to collect and arrange, 49; To make Insects' Boxes, 50; To kill and pin Insects, 51, 52; Where to find Insects, 52, 53.
CHAPTER VIII.
PARTS OF AN INSECT....           53
True Insects or Hexapods, Mouth-parts, 55; Antennee, Eyes, 56, 57; Regions of
Body, 58; Wings, 59, 60; Position of Wings, 61; How to Spread the Wings,
62; Beetle spread, 63; Abdomen, 63, 64.
CHAPTER IX.
PARTS OF AN INSECT (continued).           65
Parts of the Thorax, 65; Beetle dissected, Mouth-parts, 66-69; Appendages of the
Segments, 70.
CHAPTER X.
GROWTH OF INSECTS.......  71
Collecting Eggs, Caterpillars, Chrysalides. 71, 72; Where to collect, 73; Eggs, 74;
Raising Caterpillars, 75. 77; Chrysalis, 78. 79; Development of Chrysalis, 80;
Incomplete Chan-es, Sl; Complete and Incomplete Metamorphosis, 82; Difference between Larva and True Worms, 83-S5.
CHAPTER XI.
HABITS AND STRUCTURE OF INSECTS..                  85
Mud-wasp, 85-87; Mosquito, 83.
CHAPTER XII.
HABITS AND STRUCTURE OF INSECTS (continued).                                  89
Young Grasshopper, 89; Cast-off Skin of Grasshopper, 90; Curious Accidents, 91;
Air-tubes, 92; How Insects breathe, and how some rest, 93; Sounds produced
by Insects, 94; Stridulation of Grasshopper, 95, 96.




CONTENTS.                                     xi
CHAPTER XIII.
PAGE
HABITS AND STRUCTURE OF INSECTS (continued)..        7
Spittle Insect, 97, 98; Cicada or Seventeen-year Locust, 99, 100.
CHAPTER XIV.
HABITS AND STRUCTURE OF INSECTS (concluded).. 101
May Fly or Ephemera, 100-103; Caddis Worm, 104; Gall Fly, 104, 105; Other
Galls, 106.
CHAPTER XV.
SPIDERS......... 109
Parts of a Spider, 110; Mouth Parts and Eyes, 111; Spinnerets, 112; Legs, 113;
Habits of some, 114; Net [Building, 115; Ballooning Spiders, 116, 117; Egg
Cases, Young Spiders, 117, 118, Care for the Young, 119,120.
CHAPTER XVI.
DADDY-LONG-LEGS, CENTIPEDES, AND MILLIPEDES.         121
Daddy-long-legs, 121-123; Centipedes, 1283, 124; Mouth, Parts of, 125; Millepedes,
126; How they lay their Eggs, and Young, 127; Comparison between Myriopods and Insects, 127, 128; Some Characters of Insects, Spiders, and Myriopods,
129.
CHAPTER XVII.
CRAw-FISH AND LOBSTER....... 130
Craw-Fish, where found, 130; Reions of, 131; Mouth Parts and Appendages, 182,
133; Gills, 134; How to arrange Parts, 135, 136; Moulting, 137; Young Lobster, 138.
CHAPTER XVIII.
CRABS, HERMIEIT-CRABS, AND OTHER CRUSTACEANS.. 138
Common Crab, 189; Eggs, and how they carry them, 140; Fin-like Legs, Oyster
Crab, 141; Hermit Crab, 142-144; Fresh-water Crustaceans, 144; Sowbug and
Eggs, 145, 146; Regions of Crustacea, 146, 147.
CHAPTER XIX.
BIVALVE CRUSTACEANS AND BARNACLES..... 147
Characters of, 148, 149; Where found, 150; Appendages, how they secure their
Food, 151'; Young Barnacles, 152, 158.




xii                                 CONTENTS.
CHAPTER XX.
PAGE
WORMS                 o...1 3
Angle Worms, 154; How they move, 154, 155; Leech, 155; Sea-Worms, 156, 157;
Tube-building Worms, 159.
CHAPTER XXI.
CONCERNING NATURAL GROUPS.. 160
Characters of Articulates, 160; Of Worms and Mollusks, 161; Type Characters, 161;
Typical Animals, 162; Systematic Tables and Classification, 163.
CHAPTER XXII.
CHARACTERS OF VERTEBRATES. 163
External Characters of Salamanders, 163, 164; Comparison with Cat, 165; Differences between the two, 166; Young Salamander, 166; Skeleton of Cat, 167;
Vertebral Column and Spinal Cord, 169, 170; Bones of the Ankle and Wrist,
171, 172; Groups of Vertebrates, 173, 174.
CHAPTER XXIII.
BONES OF THE LEG AND WING O  BIRDS..... 174
Importance of studying Young Forms, 174; Wing Bones of an Adult Bird, 175;
Embryo Birds, and Wing Bones of same, 176; Leg Bones of an Adult Bird,
177; Leg Bones of Embryo Bird, 178; Leg Bones of Young Toad, 180.
CHAPTER XXIV.
CLASSES AND SUB-KINGDOMS.. 181
Sub-Kingdom Mollusca, Class Gasteropoda, 181; Class Acephala, 182; Sub-Kingdom Arthropoda, Class Insecta, 183; Class Myriopoda, 184; Class Arachnida,
185; Sub-Kingdom Vermes, Class Annelida, 185; Class Crustacea, 186; SubKingdom Vertebrata, 187.
NOTICE TO TEACHERS.... 189




FIRST BOOIK OF ZOOLOGY.
CHIAPTER  I.
FRESH-WATER SHELLS.
FoR these lessons, it has been deemed best to comimence
with the shells of mollusks, such as snail-shells and mussels.
They are better objects to examine than insects, being more
simple in structure, and less liable to be broken in handling.
When found alive, their habits can be readily studied, as
they can easily be kept alive in jars filled with water.
1. Let the pupils first malke a collection along the shores
of some lake or river, picking up all the different kinds of
shells they meet with.  The waves will have thrown them
up on the shores, or in times of drought the waters will
have left them exposed. Certain kinds are very small,
though they will be found by sharp looking.  Most of
the shells collected will be empty, and these shells are
called deacd she8ls, because the soft-bodied creatures once
contained in them  have died and decayed, leaving the hard,
limy shells.  Some of the shells collected may contain the
animal, and at one time all of them  possessed a little creature within, which was the fabricator of the shell.
1




FIRST BOOK OF ZOOLOGY.
2. IRemember that the shell is not a house built by the
snail, as a wasp builds its nest, but the shell is a part of the
animal, and is connected to it by certain muscles, so that it
cannot leave the shell, as many suppose.
The empty, or dead, shells, are to be studied first.
Looking over the shells collected, we shall find some of
the following kinds:
FIG. 1.-FRESH-WATER SHELLS,
A number of fresh-water mnussel-shells, also, will probably be collected.
FIG. 2.-FRESH-WATER MIUSSEL-SHELL.
These are to be reserved for future examination.  Those




FRESH-WATER SHELLS.                        3
having a spiral turn or twist are called snail shells, and are
to be studied first.
3. Let the pupils pick out from  their collections the
shells like these:
FIG. 3.-FRESHI-WATERt SNAIL-SHELLS.
The different spiral turns, or twists,'are called whorls,
and the whorls together form the spire. The opening into
the shell is called the caerture, and the line separating the
whorls is called the sutzure.  The pointed end of the spire is
called the apex.
avex.
suture. 
V.W~re,j~;:i. TV 7Wohbrls forming the spire.
body-whorl.
bog~~y-zhorl. n —'  ~ —------ ---- aperture.
FIG. 4. —SHELL, WITH PARTS NAMED.




4                 FIRST BOOK OF ZOO3LOGY.
In some shells the spire is elongated; in others the spire
is short; in others still the spire is depressed or flcttened.
FIG. 5.
SPIRE ELONGATED.   SIORT.         FLATTENED.
4. If the shell is held in the hand, with the aperture
toward the holder, and the spire pointing upward, as in the
figures drawn, the aperture will be either toward the right
hand, or toward the left hand.  In the figures already given,
the aperture is on the right hand, and these shells are called
clextrc/l, or right-handed, shells.
Shells having the aperture on the left hand when held in
the way above described, are called sinis~tral, or left-handed,
shells. Let the pupils here examine all the shells they have
collected, holding each one with the spire pointing upward,
and the aperture toward them, and  separate  the dextral
shells from  the sinistral shells.  As sinistral shells are not
as common as the other kind, it may be that none will be
found in the first collections made by the pupils.  The following is a figure of a sinistral shell:
Fro. 6.-SINISTRAL SHELL.




FRESH-WATER SHELLS.                     5
5. If the surface of the shell be examined closely, delicate lines running from one suture to another will be seen,
as in the figures already given; and, if the shell be looked at
from the side of the aperture, these lines will be found running parallel to the edge of the aperture, or lip, as it is
called.
These delicate lines are called lines of growth.
FIG. T. —SHOWING LINES OF GROWTH RUNNING PARALLEL TO THE EDGE OF THE: APERTURE.
The shell is increased in size by successive layers of
shelly matter added to the borders of the aperture.  In this
way the shell grows.
A clearer idea of the growth of a shell may be obtained
by studying the next figure (Fig. 8): A representing in outline a young shell; B representing the full-grown shell in
outline; and Crepresenting the same outline as B, with a
number of lines of growth represented upon it.
If the shell were now to continue its growth a single halfturn, or whorl, the dotted lines would indicate the increased
stages it would assume: a representing the first increase in
size, b the next stage, and c the appearance of the shell when
the additional half-whorl has been completed.




6                   FIRST BOOK OF ZOOLOGY.
B      A        G
C       b
FOG. 8.-ILLUSTRATING THE INCREASE IN SIZE OF A SHELL,
Among the lot of shells collected by the pupil, differentsized ones will be found. Now, if a number of these, of
different sizes, can be picked out, provided they belong to the
same kind, or species, it will be noticed that the apex of all
of them  will be the same; but that the shells have increased
in size at the aperture, and the aperture will be larger, and
the larger shells will have more whorls than  the  smaller
shells.  The following figures illustrate four different ages
of the same species of shell:
FIG. 9.-ILLUSTRATING DIFFERENT AGES OF THE SAME SHELL-THE LOWER FIGURES REPRESENTING A VIEW OF TIIE SHELL FROM THE APEX.




FRESH-WATER SNAILS.                   7
6. The axis around which the whorls revolve is called
the columelict.  This axis is generally solid, though in many
shells it is hollow, as if the whorls had turned around a
shaft which -had afterward been withdrawn.  This hollow
axis looks like alln opening in the base of the shells as in
the following figure:
FIG. 10.-A SNAIL-SHELL SEEN FROM BELOW.
This opening is called the umbiliezts.  The apex of the
shell is sometimes called the nucleuts, because the shell commences to grow from this point.
CHAPTER II.
FRESH-WATER SNAILS.
7. THE pupils will now be required to bring in some live
snails. Let them  examine bits of bark, chips, or branches,
found in ditches, or muddy brooks.  Under lily-pads and
on the stems and leaves of other aquatic plants, and on
stones in rivers, snails of various kinds will be found.  A
dipper with the bottom perforated, or made into a sieve, and
attached to a wooden handle four or five feet in length, will
be found useful in scooping up the sand or mLud from  the




8                 FIRST BOOK OF ZOOLOGY.
bottom of rivers and ditches.  The dirt having been sifted
out, the shells and other objects will be left behind.  The
dipper may be made as in the figure.
FIG. 11.-DIPPER ATTACHED TO A WOODEN lHANDLE FOR COLLECTING SNAILS.
Shells collected with the snails inside, and cleaned for
the cabinet, are called live shells.   They are always more
fresh and perfect than dead shells.
Having made the collection, the snails should be kept
alive in a wide-mouthed jar, or bottle, care being taken not
to have more t*han fifteen or twenty in a jar holding a qua rt
of water.
8. The pupils will have secured some of the following
forms:
FiG. 12.-...RESH(I SNAIS.
FtG. 12.-FEESH-WATEE SNAILS.




FRESH-WATER SNAILS.                    9
The broad, creeping disk upon which the snail rests, and
by which it retains its hold to the glass, is called the foot.
The snail moves about, and crawls or glides slowly along, by
means of the foot.
The two little horns or feelers, in front, are called tentaccles, and, as the snail moves, the tentacles are seen stretched
out in front, and occasionally bending, as if the creature were
feeling its way along. The eyes are seen at the base of the
tentacles, as two minute black dots.  The mouth is between
the tentacles, and below.  The part froln which the tentacles spring is called the head, and the opposite end of the
body is called the tcil. The surface upon which the snail
rests is called the ventral or lower surface, and consequently
that portion of the body which is above is called the dorsal
surface, or back.
9. The pupil, in watching the  habits of the  snails
he has collected, will notice some of them crawling to
the surface of the water to breathe air.  The snail accomplishes this by raising the outer edge of the aperture
to the water's edge, and then opening a little orifice in
the side, through which the air enters to the simple lung
within.
This orifice is on the right side in those snails.having
dextral shells, and on the left side in those snails having sinistral shells.
Many kinds of snails which live in fresh water are called
air-breathers, because they are forced to come to the surface
of the water to breathe air.  In doing so they first expel a




10                      FIRST BOOK OF ZOOLOGY.
bubble of air, which may be seen escaping from the breathingorifice, as in Fig. 14, B.
t  e    e    t
A view from the back,
or dorsal view.
side-viewo.
m;b
ventral view.
tt. Tentacles.
e e, Eyes.
b, Breathing-orifice.
ss, Mouth.
FIC. 18.-A FIESi-WATER SNAIL SEEN FRO2M ABOVE, FRIOM THE SIDE, AND FItRO{ WILOW.




FRESH-WATER SNAILS.                                    11
These fresh-water air-breathing snails may be kept under
water for many hours before life is extinct.
Bell
b                  34
FIG. 14.-Jar of water, in whichl is contained a number of species of mollusks, some of which
have already been studied. Some of them are near the surface, breathing air: A aend C
are taking in air; B is just expelling a bubble of air from the lung; D is crawling on
the surface of the water; E G, and I, are in the act of crawling up, to get a fresh supply
of air; and Jis a water-breather, having gills, but no lunng.
10. Among the snails collected, there will probably be
found some which have a peculiar scale on the hinder part of




12                FIRST BOOK OF ZOOLOGY.
the body.  When the snail crawls, this scale will be seen just
behind the shell, as in Fig. 15, o.
This scale is called the opemculum, and when the snail
has contracted, or drawn within the shell, the operculum is
seen to fit the aperture of the shell, closing the shell as a
stopper closes the mouth of a bottle.
FIG. 15.-SNAIL WnITH OPERCULUM. —o, Operculum; e, Eye; X, Rostrum; a, Entrance to GillCavity.
Nearly all sea-snails, that is, snails which live in salt-water,
and many species of fresh-water snails, and also many snails
which live in damp places on the land, and whicli are called
land snails, have an operculum.
When the snail has retired within the shell, the opercnlumn
will look like this in the apertnre of the shell (Fig. 16):
A series of concentric lines will be seen  marking  the
operculnum, and these are the lines of growth, the operculum
growing  around the  ounter  edge by successive additions,
just as the shell grows by successive additions to its. outer
margin.




FRESH-WATER SNAILS.                      13
The Western rivers teem  with species of snails having
operoula.
11. If the pupil has any of these operculated snails alive,
0
FIG. 16.-APERTURE Or SHELL CLOSED BY OPErCULUM, O.
he will observe that they do not come to the surface to
breathe air.
Instead of a lung, they have a cavity containing an organ, or part, called the gill, by means of which the snail is
capable of getting from  the water what the air-breathing
snail gets from the air, namely, oxygen.'
It will be seen that the head of the snail is shaped differently in the snails having an operculum, the mouth being at
the end of a sort of proboscis or rostrum.  (See Fig. 15.)
The shells, too, are, as a general thing, more solid.
12. Thus far the pupils have examined those snails which
live in fresh water.  Some of these were air-breathers, and
came to the surface of the water at intervals to breathe
air.  HIe has studied other fresh-water snails which did not
breathe air directly, but performed this function by means of
1If the class is sufficiently advanced, the teacher may here explain about
oxygen and what the blood requires, and gets by respiration.




14               FIRST BOOK OF ZOOLOGY.
an organ called the gill. And these snails were operculated,
that is, they all possessed a little scale called the operculum,
which closed the aperture tightly when the snail contracted
within the shell.
He has also learned that the shells grow in size by successive additions of limy matter deposited around the free
border of the aperture, and that the delicate lines which
mark the surface of the shell; and which run parallel to the
outer edge of the aperture, are lines of accretion, or lines of
growth.
CHAPTER  III.
LAND SNAILS.
13. THIERE are many other species of snails which live
out of the water altogether, though they are generally found
in damp places; and these are called land snails, because
they live on the land.
Let the pupils now endeavor to collect some land snails.
By going to some hard-wood grove of maple, beech, or oak,
and turning over the layers of dead leaves, old rotten logs,
or pieces of bark, they will be sure to find some specimens
of land snails. Some of them  do not grow larger than a
pin's-head, others have shells as large as a walnut.
They are generally light brown in color, and the smaller
species often have highly-polished or shiny shells.
The spire is generally depressed or flattened.  In many,




LAND SNAILS.                       15
the border of the aperture has a thickened white rim, or lip,
as it is called.  Such a collection having been made, the
pupil will find among them some of the following kinds:
FIO. 1. -THEM SHELLS OF LAND SNAILS.
14. Tilhe snail, as it crawls along, leaves a slimy trail after it.  This trail consists of a fluid, which not only flows
from the creeping disk, bnt also from the surface of the
body.  If the back of the snail is irritated by a sharppointed stick, a little whitish mass of this fluid, or mucius,
will adhere to the end of the stick.
By placing the snail on a piece of glass, and allowing it
to adhere and crawl on it, a good view may be obtained of
the peculiar movements of this creeping disk, by looking
through the glass from the other side.
The breathing-orifice may be found just within the aperture of the shell, on the right side of the snail.
This orifice will be seen opening and closing at intervals.
(See Fig. 18, b.)
15. In the fresh-water snails there are bnut two tentacles
upon the head. In the land snails with few exceptions, the




16                FIRST BOOK OF ZOOLOGY.
tentacles are four in number, a larger and a smaller pair.
The larger tentacles are called the 8stTerio2r tentaclces; the
b
b
FIG. 18.-LAND-SNAILS CRAWLING.-b, Breathing Orifice; s t, Superior Tentacles; i t, Inferior Tentacles; qn, Mouth.
smaller ones, often appearing as mere tubercles, are called the
infer~ior tentacles.  (See Fig. 18, 8 t and i t.)  As the snail
crawls, the superior tentacles are seen in constant motion, as
if the creature were feeling its way about with them.
The eyes, instead of being at the base of the tentacles, as
in the fresh-water snails, are found at the tip of the superior
tentacles.
In the land snails, with few exceptions, the tentacles can
be drawn within the head, and for this reason they are also
called retractile tentacles.
While the snail is crawling, let the pupil touch the end
of the tentacle with his finger, or, even if he alarm the snail
by a sudden jar, lie will see the tentacles quickly withdraw
within the head.  The pupil will observe that the bulbous




LAND SNAILS.                        17
end containing the eye disappears first, as the end of a glovefinger disappears, when the hand is withdrawn from  the
glove, the glove turning wrong-side out.
-A                    B
FIG. 19. —SHOWING SNAIL WITH TENTACLES RETRACTED, A; AND TENTACLES PROTRUDED, B.
16. Something may now be learned as to the way in
which land snails eat.
By placing before the snail the tender leaves of lettuce or
cabbage, the head will be seen to move, as little mouthfuls
of the leaf are bitten off.  The tpper lip of the mouth is furnished with a hardened piece called the buccal -plate.  It is
crescentic in shape, and, in some species, the cutting edge is
notched, so that it acts like an tpper set of teeth, by which
it bites off little bits of the leaf.  The floor of the mouth
is lined by a membrane having upon it rows of little points
which enable the snail to rasp and grind its food. These parts
FIG. 20. —JAW, oI BUCCAL PLATE OF A LAND SNAIL, HIGHLY MAGNIFIED.-(It can just be
discerned without a microscope.)
are so minute that they can be studied only by the aid of a
microscope.  If the pupil will watch his fresh-water snail




18                   FIRST BOOK  OF ZOOiLOGY.
as it crawls around the sides of the jar, he will see at intervals the mouth open, and a glistening tongue appear, as the
snail laps up the scumn which forms upon the surface of the
glass.
NOTE FOR TEACHERS AND PUPILS.-Let the teacher here explain to the pupils
what is meant by an object being magnified.
If the teacher has a common magnifying-glass, let each pupil in turn observe
its magnifying effect, by looking at a common house-fly, or the printed page of a
book. If a microscope can be shown the class, it will be better still.
Let it be explained, also, what is meant by an object being enlarged two, or
three, or more times. To be enlarged two or three times, is to make the object
two or three times as long as it was before, and of proportional bigness.
Oftentimes the object has to be reduced in size in the figure, as in pictures of
large animals, in the picture of an elephant, for example.
In representations of very small animals, however, the figure has to be enlarged in order to show parts plainly that could not otherwise be seen, were they
drawn natural size, that is, a size corresponding to the actual size of the animal.
Thus in Fig. 24, b and c are greatly enlarged, to show the little snail within the
egg.
17. In searching for snails, the pupil will come across
snail-like animals, which have no coiled shells on their backs.
Let the pupil examine the under side of damp boards or
plank walks in gardens, and he will be sure to find them.
They are very common in old gardens in  cities.  These
FIG. 21. —A SLUG CONTRACTED.
creatures will be found  clinging to the board or upon the
ground, and will present this appearance (Fig. 21). Soon,
however, they will stretch out their tentacles, and commence




LAND SNAILS.                      19
to crawl, and then their resemblance to the shell-bearing
snails will be seen at once.
Instead of having a coiled shell into which they can
retreat when alarmed, they have a little limy scale inlbedded
in a portion of the back, called the mqantle.  The breathingorifice is on the right side of the body, and the tentacles,
mouth-parts, creeping disk, and other features, are quite
similar to the land snails already studied.
a       b
FIG. 22. —A NAKED LAND SNAIL, OR SLUG, FULLY EXPLNDED. —a: Mantle; b, BreathingOrifice.
18. On the approach of winter, land snails bury themselves in the ground, and those that have shells retire within
the shell as far as possible, and close the aperture of the shell
with a film of the mucus which the body secretes so abundantly.  In this condition they remain dormant until the
warm weather of spring revives them again.
If the pupil will collect a lot of snails in the early spring,
and keep them confined in a box, with earth, damp leaves, or
bits of rotten wood or bark, the snails in the course of a few
weeks will lay a number of little eggs. These eggs will be
white and round, about the size of a pin's-head. By careful
tending, that is, by keeping the leaves slightly moist, the




20                 FIRST BOOK OF ZOOLOGY.
eggs will hatch out tiny snails, and these will attain half
their mature size the first season.
a          e
000 0 0
Po (
00
FrG. 23.-a, Eggs of Land Snail; b, Young Snail just hatched; c, Young Snail somewhat
advanced: b and c are magnified.
19. If the pupil will also collect a lot of fresh-water airbreathing snails, and keep them alive, they will deposit their
eggs upon the sides of the glass jar in which they are confined.  These eggs will be oval in shape, and transparent,
and will be inclosed in a transparent, jelly-like substance. Fig.
14, Il, represents the appearance of a cluster of these eggs.
Fig. 24 shows a cluster of eggs with the appearance of
two eggs highly magnified, showing the young snails as they
appear within the egg.
a          b           c
FIG. 24.-a, Cluster of Eggs of a Fresh-Water Snail; b, e, Eggs enlarged, showing the
young Snails within the Eggs.
With the aid of a magnifying-glass, the eggs may be
watched from day to day, and the young snail can be seen in
its various stages of growth.




LAND SNAILS.                       21
20. If a land-snail is taken out of its shell (and this can
be done if boiling water be first poured upon it, and then
with a pin the animal can be readily picked out), it will present this appearance (Fig. 25):
FIG. 25.-LAND SNAIL REMaOVED FROM ITS SHELL. —m, Mantle.
The portion contained within the shell presents the
same general appearance as the shell itself. A free border,
or collar, is seen which corresponds to the aperture of the
shell.  This border is called the mzantle, and is a characteristic feature of all the snails thus far studied. It is the edge
of the mantle which deposits the successive layers of the
shell, and increases its size. In the slug, there is only the
liniy scale; this is buried in the mantle, which is plainly seen
covering a portion of the back, like a shield (Fig. 22, a).
CHAPTER IV.
SEA SNAILS.
21. CLAssEs that live near the sea-coast may now study
the marine, or salt-water snails. These may be collected
alive at low tide, upon rocks, or under the sea-weed. By




FIRST BOOK OF ZOOLOGY.
examining pools left at low tide, many little sea snails may
be seen creeping about.
A good place to collect dead shells may be found along
an exposed beach. After a violent storm, when the waves
have been running high, a great many animals are thrown
up from  the sea, and among them  many shells may be
secured.
The following will be some of the shells collected:
FIG. 26.-COMMON SEA SNAILS.
22. With very few exceptions, all sea snails are waterbreathers; that is, they are furnished with gills, instead of a
simple lung. Most of them are operculated.
In the shells collected the pupil will find two wellmarked groups.
In the two lower right-hand figures of Fig. 26, the
shells have an aperture with a continuous border; that is,




SEA SNAILS.                       23
there is no notch, or fold, in it. In the three upper figures
there is a notch, or fold, in the base of the aperture.
FIG. 27.-SHELL SHOWING LONG CANAL.
This notch is called the canal, and in some species it is
very short, while in other species it is very long, as in Fig.
27.
The mantle of the animal is prolonged in a fold which
occupies this canal, and is called the siphor. Through this
fold or siphon the water finds access to the gills.  (Fig. 28
shows another species. The siphon is seen as a fold of the
mantle running into the canal of the shell.)
23. A very common species, found in the greatest abundance from Maine to Florida, on mud-flats, will give a good




24                    FIRST BOOK  OF ZOOLOGY.
illustration  of the uses of the siphon.   In this particular
species, the siphon is much longer than  the canal, and, when
the snail is crawling, the  siphon  is bent upward.  As the
e l
= \
FIG. 28. —A  SEA SNAIL SEEN FROM BELOW.-C, Eye; m, Mouth; s, Siphon.
habit of this species is to  crawl along partly buried in the
mud, the  siphon, projecting  above the  level of the  mud,
conducts the pure sea-water to the gills of the snail below.
Fig. 29 illustrates the appearance of this snail:
A                i,C
FIG. 29.-A, the Snail crawling upon the Surface of the Mud; B, the same slightly buried; C,
the same nearly buried; the Siphon, s, is seen curved upward.




SEA SNAILS.                      25
Such shells are called canaliculated shells.
The aperture of the shell is said to be entire, when it
does not possess this notch, or canal. Let the pupil separate
the shells having the aperture entire, from those shells having a canal.
These differences in the shell, as slight as they appear,
are accompanied by corresponding differences in the character and habits of the animal.
Those snails having the aperture of the shell entire are
with few exceptions vegetable-feeders, while those having a
canal to the shell are flesh-feeders. The mouth-parts, and
opercula, too, are different in the two groups.
24. Other shells will be found differing greatly in appearance from  those thus far studied.  One of these is represented in the lower left-hand corner of Fig. 26.
Another species, called the limpet, looks like this (Fig.
30):
FIG. 30.-SHELL OF LIMPET.
These shells will be found sticking with great tenacity to
the rocks, and some skill and force will be required to
remove them. This can be done by using the large blade
of a pocket-knife, and suddenly scraping them from the rock.
If they are then placed in a saucer of water, with the shell
downward, the animal within  will be found to have the
broad, creeping disk, head, tentacles, and other parts, peculiar
to the snails already studied.
2




26                   FIRST BOOK  OF ZOOLOGY.
25. In  the  land  snails, it was  learned  that the eggs
were deposited separately, while in  the air-breathing, freshwater snails the eggs were inclosed in a gelatinous substance.
Among the sea snails there are many species which inclose
their eggs in pods, or capsules, as is also the case in the operculated  fresh-water  snails.   Sometimes  the  capsules  are
clustered together in large masses, as in those of the whelk
(Fig. 31):
FIG. 31.- A VERY SMALL CLUSTER OF EGGS OF THE WHELK DEPOSITED ON THIIE STEM Oi
A LARGE SEA-WEED.
In others they are united in a long string (Fig. 32).
A                     S        B
FIG. 32.-A, a Portion of a String of Egg-Capsules, from a Florida Species of Whelk similar
to Fig. 27; B, a single Capsule separated, showing Outlet, o, through which the Young
escape; s, Stem,
The common  cockle sticks its separate egg-capsules side
by side upon the rock (Fig. 33).




FRESH-WATER  MUSSELS.                         27
The beach-cockle deposits its eggs in a broad ribbon of
sand  cemented  together, looking  very much  like  a  deep
saucer, with the bottom broken out, and the side separated
(Fig. 34).
FIG. 83. —EGG-CAPS-ULES OF COMMON COCKLE.-(A shell of the animal which produces these
capsules is shown in the upper central figure of Fig. 26.)
This ribbon is elastic when wet, and, if it is held up to
the light, the little transparent spaces for the eggs will be
plainly seen.
E   o BEA COCL (the shell of which is shown in the lower
FriG 34.-EGG- RIBBON OF BEACH-COCIrLE (the shell of which is shown in the lower
right-hand figure of Fig. 26).
CHAPTER V.
FRESH-WATER MUSSELS.
26. LooKING over our fresh-water shells again, we find
many that are known as mussels, or clams. These shells are
common everywhere along the margins of brooks, rivers, and
lakes.  The musk-rats feed upon the soft parts of the mus



28               FIRST BOOK OF ZOOLOGY.
sels, and the remains of their feasts may be found in piles of
mussel-shells all along the shores of certain lakes.
The shell is composed of two pieces, or valves, as they are
called. The two valves are often found united, and the
margin along which they are connected is called the hingemargin, because the shells hinge at this part, and will open
and shut as a door swings upon its hinges.
Let the pupil now examine a perfect fresh-water mussel,
that is, a mussel in which the valves are united in this way,
and he will observe that they are connected by a brownish
substance, which is quite elastic when the shell is alive, but
becomes brittle when dried. The shells are held together as
the covers of a book are held together by the back.
This substance is called the ligament, and the position of
this ligament will indicate the back, or dorsal region of the
animal.
27. On the outside of the shell will be seen fine lines,
which run nearly parallel to the outside margin of the shell.
These lines are the lines of growth, and indicate the successive stages of growth, or increase of the shell, as in the lines
of growth in the snail-shell already studied, and, as in the
snails, the growth takes place at the margin of the shells.
The pupil may trace these concentric lines back, as they
grow smaller and smaller, till they are found to start from
one point at the back of the shell, and this point is called
the beak or uzmbone.  It represents the starting-point in the
growth of the shell. In fresh-water mussels, the umbones
are eaten away by some corrosive action of the water, and the




FRESH-WATER MUSSELS.                    29
early stages in the growth of the shell are usually destroyed.
In very young shells, however, the early stages can be plainly
seen.
Back or dorsal region.
u       1.g.-O       v                  i        S;.;                                                   F
f Ventral region.
FIG. 35.-A FRESH-WATER MUSSEL. —I, Ligament; x, Umbone; f, Foot; ex., Excurrent
Orifice; in., Incurrent Orifice.
28. The ligament is always behind the beak, or umbone,
in fresh-water mussels, and in nearly all bivalve shells (so
called, because they have two valves or pieces, while the
snail-shells are sometimes called univalve shells, because they
have but one valve or piece).
Let the pupil now hold a perfect mussel-shell in his hand
(that is, a mussel in which both valves are together, and
united across the back), with the ligament uppermost, and the
umbone away from him, or beyond the ligament, and the
valve on his left hand is the one which covers the left side
of the animal, while the valve on his right hand covers the




30                FIRST BOOK OF ZOOLOGY.
right side of the animal.  The forward end will be the end
away from  him, and the hinder end will, of course, be the
end toward him.  (See Fig. 35.)
29. Let the pupils now endeavor to collect some freshwater mussels alive.  These may be found partly buried in
the sand or mud of rivers and lakes.  As they crawl along
partly buried in this way, they plough up the sand, leaving a
well-marked furrow  or groove behind them.  Every boy
that goes in bathing is familiar with the peculiar furrow left
by the fresh-water mussel.  By following such a furrow, the
mussel that made it will soon be found.
Fig. 36 represents the appearance of a common freshwater mussel in the act of crawling.
FIG. 86.-SHOWING POSITION OF MUSSEL WHEN CRAWLING.-f, foot buried below the surface
of the sand s. Above the line s is supposed to be water, the line representing the bottom
of a lake or river.
Having collected a few in this way, they may be placed
in a large, shallow pan of water, and allowed to remain quiet
for a while. Gradually the shells will open a little, and from
the hinder end a curious fringed border appears; on examin



FRESHI-WATER MUSSELS.                 31
ing this border, it will soon be found that the border forms
two openings which lead into the shell.
Great care must be taken not to jar the dish, or the table
upon which it rests.  The slightest jar will cause the shells to
instantly close.  If some indigo, or small particles of dirt, be
dropped near these openings, currents of water will be revealed; one Current pouring out of the opening nearest the
back, and another current as steadily pouring in at the other
opening.  The opening into which the current of water is
passing is called the incurrent orfjice, while the orifice from
which a current of water is passing is called the excurrent
orkfice. The incurrent orifice is sometimes called the respiratory orifice, because the water is taken in to supply the gills
which are the breathing or respiratory organs of the mussel,
and this orifice corresponds to the siphon in the sea snails
already studied. This current of water, besides bathing the
gills, also carries in minute particles which are floating in
the water, and these particles are conducted to the mouth of
the creature, and swallowed as food. At the opposite end of
the shell from these openings, or the forward end, a whitish,
fleshv mass will be seen protruding. This is called the foot,
and corresponds to the foot or creeping disk in the snails.
By means of this foot the mussel crawls through the sand.
The mouth is above the foot, and always concealed within
the shell.  In Fig. 35 the foot is shown, and also the excurrent and incurrent orifices, with arrows drawn to indicate
the direction of the currents of water.
In some small species of fresh-water bivalves, the excur



32              FIRST BOOK OF ZOOLOGY.
rent and incurrent orifices are prolonged into tubes, and then
they are called siphons. Fig. 37 represents a common species which the pupils may find in muddy brooks and ditches.
By using the long-handled dipper already described, some
specimens will probably be found. They are quite small,
from the size of a pea to that of a nickel cent. The siphonal
tubes are prominent, and the foot is long and tongue-shaped,
and the animal is very active in crawling about; also in Fig.
14 K and L represent two of these small animals with bivalve shells.
FIG. 3T.
30. The foot of these creatures resembles in appearance
and action the foot of a fresh-water snail, only there is no
mouth nor tentacles in sight. These parts are present, but
are never protruded beyond the edges of the shell.
When the fresh-water mussels are partly open, a fleshy
border will be seen just within the edges of the shell, and
this is the border of the mantle, and corresponds to the same
parts described in the snails; the fringed membrane which,
formed the openings at the hinder part of the mussel is
simply a continuation of the mantle.
When the shells are removed from the animal, the mantle
will be found lining the shells, just as the blank pages line
the inside of a book-cover.  While the edge of the mantle deposits the successive layers, which increase the size of




FRESH-WATER MUSSELS.                    33
the shell, the entire surface of the mantle deposits the pearly
substance which lines the inner surface of the shells, and
which is so characteristic of the fresh-water mussels.
31. Grains of sand, or other particles, getting in between
tile mantle and the shell, are soon covered by layers of pearly
substance poured out, or secreted by the mantle. In this way
pearls are formed.
If pearls are broken open, a centre, or nucleus, will be
found, consisting of some particle of dirt or sand, or some
stbstance which had found its way by accident between the
mantle and the shell, and around which the pearly matter
has been formed in successive laSyers.
A Co o 
FIG. 38.-A, Pearly Concretions from a Fresh-water Mussel; B, Pearly Concretions from
the Common Oyster.
In shells having a brilliant, pearly lining, or nctcre, the
pearls obtained are oftentimes very beautiful, and from  certain Oriental species living in the sea, called Avicuca, the
most brilliant pearls of commerce are obtained.  If, on the
other hand, the nacre lining the shell is dull white, as in the
common oyster, the pearls are dull-colored.  This kind of
pearls is often found in oysters.
The Chinese have long been familiar with the art of




34              FIRST BOOK OF ZOOLOGY.
making artificial pearls. By partly opening the shells of
certain fresh-water mussels, and inserting little lead images,
or other objects, between the mantle and the shell, the objects soon become covered with a natural layer of pearl.
32. Let the pupils now study the markings on the inner
surface of the shells of river-mussels. The shells of these
creatures are called valves, and are spoken of as right or
left valves, according to whether they are on the right or left
side of the animal.
Certain ridges and prominences will be seen at the hinge,
and, when the valves are carefully joined, the ridges in one
valve will correspond to gFooves in the other valve.  These
ridges are called teeth. The short ones, near the beak, are
called cardinal teeth, and the long ones lateral teeth.  The
margin upon which they occur is called the hinge-mnargin, for
it is upon this margin that the valves turn. (See Fig. 39.)
33. Certain scars, or impressions, will be found marking
the inside of the valves, and these indicate the point of the
attachment of certain muscles to move the valves, and to
enable the animal to protrude its foot, and crawl along.
These marks are hence called muscular marks, or qnuscular impressions, and will be found to correspond in the right
and left valves.
An irregular, round impression will be found at each
end of the valve, near the hinge-margin. These show where
the muscles are attached to move and close the valves,
and hold them firmly together. The muscles run directly
across from one valve to the other; and, to open a live




FRESH-WATER MUSSELS.                       35
mussel, it is necessary  to  pass  a  sharp  blade  between
the valves, and cut through the muscles, before the valves
will open.  These muscles are called the adcfductor muscles,
and the scars or impressions on the valves are called the
ccdductor muscular imrpressions.  Very close to the adductor
muscular impressions are seen smaller impressions, and these
indicate where the muscles are attached which move the
foot.  These muscles are called the pedal muscles, and the
impressions are called the pedal mnuscular imnpressions.  One
occurs just behind the  anterior adductor impression; the
other will be found just above, and in front of the posterior
adductor impression.
c       Mt              1i     g
1119
ap
BIG. 89.-THE RIGIHT V'ALVE OF A FRESH-WATEI MUSSEL.-C, Cardinal Teeth 1, Lateral Tooth;
Ri, Ligamnent; aa, Anterior Adductor Impression; )ca, Posterior Adductor Impression;
iap, Anterior Pedal Muscular Impression; p2p, Posterior Pedal Muscular Impression;
A, Pallial Line.
34. Besides these marks, the pupil will see a delicate
and slightly irregular line running from  the anterior to the




36               FIRST BOOK OF ZOOLOGY.
posterior muscular impression, just inside, and nearly parallel
with the lower margin of the shell. This line is called the
palliac line, and indicates where the mantle is attached to
the shell.  It will be observed that, when the soft parts are
removed from the shell, the mantle adheres along this line.
The pupil may mark with a pen the names of all the
parts upon the inside of a fresh-water mussel.
35. When the mussel is opened by separating the adductor muscles with a knife, the valves slowly open, and
after the animal is removed the valves still remain partly
open, and, to preserve them  closed, a string has to be tied
around them, and in this condition, if the ligament is allowed
to dry, the valves will then remain closed. From this it is
evident that the ligament acts upon the valves to draw them
apart.  To keep them closed, then, the animal mnst continually exert itself by contracting the addclctor muscles; and it
will be found that, when these creatures are left in the water,
undisturbed for a while, the muscles relax, and the valves
partly open. The ligament is elastic, and is stretched as it
were from one valve to the other, over the back. A possible
imitation of the action might be represented by partly opening the lids of a book, and then gluing across the back, from
one lid to the other, a sheet of elastic rubber.  If, now, the
lids are tightly closed, the rubber is drawn out, or stretched
across the backl and, if allowed to regain its elasticity, the
lids are pulled apart. This experiment illustrates the way in
which the ligament acts in those shells which have the ligamient external.




CLAMS, MUSSELS, AND OYSTERS.               37
CHAPTER VI.
CLAMS, MUSSELS, AND OYSTERS.
36. CLASSES having access to salt-water may now collect
a lot of bivalves, as the clam, mussel, razor-shell, oyster, scallop, and whatever species they can find belonging to this
group. A much greater variety of forms will be found in
salt-water than in fresh-water.
Among some of the common species met with will be
the following:
FIG. 40.-SALT-WATER BIVALVES.
In these the pupil may trace out the muscular impressions within the shell, and make Out their relations to the
impressions already described in the fresh-water mussels.




38               FIRST BOOK OF ZOOLOGY.
Many differences will be observed in the muscular impressions, as well as in the teeth and the position of the ligament.
37. As the common soft-shelled clamn'can be readily procured in the fish-markets, it will be well to study this first.
A live specimen must be selected, and, as the clam lives a
long time after it has been removed from  the water, there
will be no difficulty in getting the proper specimen.  Upon
pressing the valves together, or touching the soft parts which
partly protrude from between the valves, the creature will
show signs of life, by drawing the shells closer together, and
this will assure the pupil that the specimen is alive.
A  large shallow dish may now be filled with pire seawater, and in this the clam  may be placed.  After it has
remained there for some time, the black end of the animal,
which is incorrectly called the head, will slowly stretch out
from between the shells, and the end, unfolding, will display
two openings fringed with little feelers (see Fig. 42). Into
one of these openings the water will be seen flowing, while
from the other a current of water will be seen issuing. And
these openings are called the incurrent and exeurrent oriTices,
and correspond to similar parts previously described in the
fresh-water mussels.  In the latter creature, the openings
just protruded beyond the edge of the shell. In some very
small species of fresh-water bivalves, one of which was shown
in Fig. 37, these openings were at the end of separate tubes.
In the clam the tubes are inclosed in one sheath.
The clam can protrude this apparatus to a length equaling that of the shell two or three times.  As the clam lives




CLAMS, MUSSELS, AND OYSTERS.            39
buried at some depth below the level of the sand or mud in
which it occurs, it requires this extension of the openings
to reach the sea-water above.
38. It may be stated here, that the current of water
passing into the general cavity of the shell not only carries
the particle of food upon which the animal subsists, but conveys the pure sea-water to the gills by which it breathes,
the gills performing the same function for animals living
immersed in water as the lungs perform for creatures which
breathe air. All bivalves depend upon currents of water to
convey their food to them.
While, in the snails, the creatures could go in quest of
food, having the power of protruding the head from the
shell, and their mouths furnished with means to bite or rasp
their food, in the bivalves there is really no head, they having only a little opening directly under the anterior adductor
muscle, which is the mouth, and into which the particles of
food are swept.
39. If, now, the clam is opened, the edges of the mantle
will be found much thiekened and united, except a small slit
near the front edge, through which can be protruded a small,
tongue-shaped foot. Powerful muscles will be found at the
base of the united siphons or tubes, which move the siphons
in and out, and an examination of the inside of the shell will
show where these muscles are attached.  The pallial line,
instead of running directly from the anterior adductor impression to the posterior oiie, is abruptly curved back, and
forms a sharp bend, as it turns again to the posterior ad



40               FIRST BOOK OF ZOOLOGY.
ductor impression.  This mark is called the sinus, and, when
present, indicates the siphons to be of considerable size, and
having large muscles to contract them.
Let these parts now be marked with a pen upon the shell,
with their names, as in Fig. 41:
FIG. 41.-RIGHT VALVE OF A COMMON CLAM.-I, Ligament; aa, Anterior Adductor
Impression; pee, Posterior Adductor Impression.
40. On opening the shell, a prominent tooth is seen
on one of the valves near the hinge, while on the other
valve there is a corresponding depression. When the valves
are forcibly separated, there is left attached either to the
tooth, or in the depression, a substance resembling dark glue,
very elastic, and firmly attached to its place.  This is the
ligament, and is said to be internal, because it is within the
shell, and not upon the outside, as in the fresh-water mussel
already studied. When the animal closes the shell by contracting the adductors, the ligament is compressed, by being
jammed between the prominent tooth, and the recess into
which it fits. When the muscles relax, the ligament expands,




CLAMS, MUSSELS, AND OYSTERS.                                41
ex.    in.
B                             A                 f
FIG. 42.-CO-MaoN CLAM.-A. showing Siphons partly extended; in., Incurrent Orifice; ex.,
Excurrent Orifice; f, Foot; in, thickened border of the Mantle projecting beyond the
Edge of the Shell; B, Siphons, greatly extended. (The shell is not drawn, as there was
no room for it on the page.) The excurrent and incurrent orifices are more open than in A.




42               FIRST BOOK OF ZOOLOGY.
forcing the valves apart.  The way in which it works might
be illustrated by placing a piece of rubber inside the hinge
of a door: when the door is closed, the rubber is squeezed,
and the tendency would, of course, be for the rubber, in expanding, to again push the door open.
That it requires a continual effort for the clam to keep
the valves closed, is seen in the fact that when these
creatures are allowed to remain out of water for a while, as
they are when in the market, the muscles get tired, and,
relaxing, the shells partly open.  If, now, the basket or
barrel which they are in be suddenly shaken, the clams
will as suddenly close, and a rustling sound is made, as the
water is forced out from  the gill-cavity, the water often
squirting out in a stream from the siphonal openings.
41. On the rocks between high and low water mark, and
adhering to the piles of the wharves, may be found clusters of
mussels which are attached to these places, and to each other,
by little brown threads which issue from between the valves
below. These threads are made at will by the creature, one
by one, and are fastened to the substances upon which they
rest.  The threads are called byssca-threads, and, combined,
form the byss8s.
If the pupils will collect a number of these salt-water
mussels, and place them in a large glass dish or bowl filled
with salt-water, they may watch the mussels as the creatures
attach themselves to the sides of the vessel. In the figure,
the byssus is seen like threads coming from between the
valves below, with their ends adhering to the stone.




CLAMS, MUSSELS, AND OYSTERS.                 43
42. Fig. 44 represents an animal which is often thrown
up on beaches along the coasts, after a storm, and whose shells
are very common in the debris thrown up by the waves.
FIG. 43.-A MUSSEL ATTACIIED TO A STONE BY ITS BYSSus. —f; Foot.
These shells are very thin and delicate, and the valves are
strengthened by a thickened rib which runs from the umbone
toward the lower margin of the valve within.
In this species the siphons are united, the mantleprojects
beyond the edge of the valves, and the foot is flattened in
front.
I                          ee.  in.
f                m
RIG. 44. —, Ligament; f, Foot; m, Mantle; s, Siphons; ex., Excurrent Orifice; in., Incurremnt
Orifice.
Fig. 45 represents another animal which is often abundant on the sea-beach. In this species the siphonal tubes are




44               FIRST BOOK OF ZOOLOGY.
separate, instead of being united. This figure represents the
tubes only partly extended. They can be thrown out to
twice the length represented in the figure.
excurrent siphon.
incurrent or branchial
siphon.
FIG. 45.
Another species quite similar to the above occurs on mud
flats, in company with the common clam. If this be collected alive and placed in sea-water, the creature will extend
its siphons, which are long and separate, and bend them  in
coils.
43. The pupils have now learned, among other things,
a few features regarding the position which certain bivalves
occupy in their native haunts: the fresh-water mussel creeping by means of its foot through the mud or sand in which
it lives partly buried; the salt-water mussel, fastened to
some place by means of its byssus; the soft-shelled clam,
lying buried at some depth in the mud, and extending its
siphons to conduct the pure sea-water to its gills, and food to
its mouth.
The oyster differs considerably from  these animals to
which it is related, and which have just been studied. Instead of being free, they grow attached by one of their valves
to the rock and to each other; clusters of a dozen or more individuals of different sizes are found growing, attached to
each other, and forming large masses. At any oyster-market




CLAMS, MUSSELS, AND OYSTERS.          45
the pupil may get these clusters. Before studying a specimen, it is best to clean the shell thoroughly in water by means
of a coarse brush.
44. Instead of having two adductor muscles, it has but
one (though this muscle, it seems, is composed of two elements). A single dark-purple mark on the inside of each
valve shows the point'of attachment of the adductor muscle.
When the oyster is opened, the mantle contracts somewhat,
so that the edge of the mantle is some way from the margin
of the shell, as shown in Fig. 47.
The left valve is the larger, and is the one that becomes
attached; the right valve is flattened, and somewhat smaller.
The mantle has its margins free; that is, the edges are not
united as in the common clam, where they are not only
united, but greatly thickened. Neither is the mantle prolonged into siphons as in other species; consequently, the
water flows in at one portion of the shell, and pours out of
another portion, not being definitely conducted by special
channels, as in those forms heretofore given.  The oyster
can be readily studied, as specimens may be got in almost
every village in the country.
In looking over canned specimens, be sure and pick out a
large one, and one that does not appear to be mutilated, as
they frequently are when taken out of the shell by the oysterman, or jammed, as they often are in packing.
To those who can get them alive, it is well to have the
oysterman open the specimen, being sure that he removes
the larger valve, leaving the oyster attached, and resting in




46              FIRST BOOK OF ZOOLOGY.
the smaller and flat valve, which is the right one. To examine it properly, the specimen must be placed in a deep
saucer filled with water, so as to cover it. A number of
rinsings will remove the mucus with which the oyster is
covered, and this will render the specimen in better condition to examine. In placing it under water in this way,
the membranes float apart, and can be more readily
studied.
45. The adductor muscle is near the middle of the animal.
It is composed of two elements, one half being a glistening
white, and the other half being grayish. Imlnmediately adjoining the grayish portion of the muscle, a translucent space
is seen, and this space contains the heart, composed of a body
constricted in the centre, as if a tube bad been tied in the
middle by a string. This is the heart proper, and in specimens freshly opened the heart may be seen to slowly pulsate,
or beat.
By raising the mantle, the gills will be seen as delicate,
leaf-like membranes.
At the smaller end of the oyster, and that portion which
comes next to the bealk or hinge, the mouth will be found
having on each side two delicate lappets which are called the
palpi. It will be difficult to find the mouth, and some patience will be demanded in lifting the mantle and following
up between the palpi to where the mouth is.
The dark region just back of the mouth contains the
stomach and liver; the dark or blackish portion, showing so
conspicuously in cooked specimens, being the liver.




CLAMS, MUSSELS, AND OYSTERS.                   47
By referring to the accompanying figures, these parts
may be readily made out:
FIG. 46.-OYSTER ATTACED BY LEFT VALVE TO A STONE.
m
FIG. 47.-OYSTER WITH THE LEFT VALVE RtEMOVED. —I, Heart; 1, Ligament; m, Position
of Mouth.
46. The pupil will now recall some characters in common
between the snails, and the mussels, clams, and oysters, thus
far studied in these lessons, namely: they all have the body
protected by a limy shell (except the slug), this shell either
composed of one piece, as in the snails, or of two pieces or




48                FIRST BOOK OF ZOOLOGY.
FIG. 48.-RIGHT VALVE' OF AN OYSTER, the Dark Semicircular Malrk near the Middle of
the Shell being the Adductor Muscular Impression, the Pallial Line showing faintly.
valves, as in the clans, mussels, and oysters. All of them
increase the size of their shells, or grow, by the addition of
layers of shell-material to the edge of the aperture, or the
margins of their valves, and these layers are indicated by
delicate lines seen on the outside of the shell, and called lines
of growth.  They all have the creeping disk, or foot (excepting the oyster). In the snails, this is broad and flat; in the
mussel and clam the foot is flattened sideways, and variously
shaped. In the snails, the creature projects, with the foot,
a head furnished with feelers, or tentacles, and the mouth is
possessed of certain hard parts by which food can be eaten.
In the mussels and clams there is no definite head, the mouth
being hidden away within the mantle, and the creature projecting, from the forward end, only the foot. In all of these
animals thus far studied there is a cavity within, containing
the gills to which water has access, or else there is a simple




COLLECTING INSECTS.                 49
lung, as in the air-breathing snails.  These, with the cuttlefishes, which we will not consider here, belong to a branch of
the Animal Kingdom called Mollusca.
CHAPTER VII.
COLLECTING  INSECTS.
4X. THESE lessons, as well as the preceding ones, are
prepared with the understanding that the pupils shall make
a collection as far as possible of the species of animals studied. In fact, it is a part of the lesson to know how and
where to collect, and above all to know how to preserve the
specimens collected.  To enable the pupils to do this, the
briefest directions are given for the making of boxes, nets,
etc., accompanied with the simplest methods of preserving
the collections made.
In many cases the directions given are by no means the
professional methods; tlus.the pupils are directed to use
common pins for insects, while the professional collector uses
only the true insect-pins made expressly for the purpose, but
these are oftentimes difficult to procure, and are more expensive than the common ones.
In collmencing these lessons, each pupil must first be
provided with a nLnmnber of common pins, and a box properly arranged in which to pin the insects collected.
Some holiday afternoon, or an hour before school-time
3




50               FIRST BOOK OF ZOOLOGY.
in the morning, may be spent in making the insect-boxes.
These may be of any convenient size, having a depth of not
over two and a half or three inches, and furnished with a lid.
A shallow cigar-box will answer the purpose.  The bottom
of the box may be lined with strips of corn-pith, or slices of
cork, into which the pins can be easily stuck.  Large corkstoppers will do, and these may be cut into lozenge-shaped
pieces like this:
FIG. 49.-SLICED COR1K FOR INSECT-BOX.
These pieces are to be fastened to the bottom of the
box by gluing. If strips of corn-pith are used, they may be
tacked or glued to the bottom of the box. The box, when
finished, will look something like this:
Co OD
FIG. 50.-INSECT-BOX.
48. The insects, when collected, are to be pinned to the




COLLECTING INSECTS.                51
cork in the way figured, leaving the head of the pin sufficiently above the insect to grasp with the fingers.
Care nmust be taken not to have the insect too far down
on the pin, as its legs in that case would touch the bottom  of
the box, and break off. Insects may be killed by immersing
them in alcohol for a few minutes.
FIG. 51.-INSECT PINNED
Butterflies may be killed by compressing the body between the thumb and forefinger, as shown in the figure,
using just force enough to kill, without crushing them.
The fumes of benzine, or ether, and of certain poisons, will
also kill insects, but these substances should not be suggested
to young pupils, as their use is dangerous.  (Teachers will
here use their judgment according to the character of their
classes.)  The rude box and common pins are offered simply for experimental collections. The ingenuity of a pupil,
where neater collections are desired, will readily secure better ways of making them.
49. The pupils may go out in a class in quest of material




52               FIRST BOOK OF ZOOLOGY.
for study, and this is the best way, as the activity and success of one will act as a stimulus to the others.
FIG. 52.
In the country, the best places to collect are by the roadsides, or borders of woods and groves; in the gardens, and
by the fences, or along the shores of lakes and brooks, under
stones and stumps, the bark of fallen trees, or beneath the
layers of dead leaves.  Insects are scarce in deep woods, and
in large, open tracts of pasture-land.
In the cities, the parks and gardens will afford good
collecting-grounds, as under plank-walks and boards many
insects find shelter.  Alongside of railroad-tracks the discarded sleepers often hide many a curious beetle. In short,




PARTS OF AN INSECT.                  53
let the pupil peer under any object large enough to afford
shelter to these creatures. By following the furrows made
by a plow, certain kinds will surely be met with.  The pupil
must be urged to pick up every thing that he thinks is an
insect, such as grasshoppers, beetles, flies, ants, spiders, etc.
In a single holiday afternoon the pupil will have gathered some of the following animals:
FIG. 53.-SOME OF THE ANIMIALS COLLECTED,
CHAPTER  VIIi.
PARTS OF AN  INSECT.
50. TEm animals are now to be carefully examined.  Let
the pupils pick out, and arrange together in one portion of
the box, all of those which have three pairs of legs.  In




54                 FIRST BOOK OF ZOOLOGY.
some, the legs will be closely drawn to the body, but by
sharp looking they will be found.
After studying these Carefully, the pupil will observe
that those insects which have three pairs of legs have the
body divided into three regions, or parts, called respectively
the hiead, thorax, and abdoven, and that, with few  exceptions, they all have wings. Insects having these characters
are called Ihsect8 prop2er.   They are also called f1Iexapods,
a word meaning six legs.
These are to be studied first.  The other animals collected may be saved for future study.
51. Some insects have the three parts of the body distinctly separated, as in the ants, flies, and wasps. In other
insects the parts of the body are very close together, so that
it is difficult to distinguish the dividing line, as in certain
beetles.  Let the pupils examine each insect, and make out
the head, thorax, and abdomen.
-_ —[_ —h —e-'_'.) head.
Insect with the head, thorax,                tJ
and abdomen, distinctly.            )..
separated.                     -----------
a j bdomen~.
} thorax.
Insect with the head, thorax,...     3.......
and abdomen, close to-                    a dome.
gether.                                  abo
FIG. 54.
In the head, we find the mzouth, the eyes, and the feelers,
or antennce.




PARTS OF AN INSECT.                        55
The mouth is on the under side of the head, and is surrounded by certain parts called rnouthxparts.   These parts
differ greatly in different insects.
52. In those insects that chew their food, such as the beetles and grasshoppers, certain of the mouth-parts act as teeth,
or jaws, and, being joined to the right and left sides of the
mouth, move sideways, and not up and down, as in other
animals. In other insects some of the mouth-parts are very
long and slender, so as to form a long, sharp sting, as in the
bugs proper, so that they use them  to suck the juices of
plants upon which they feed. Or, the parts are again modified in shape to form a long, slender tube, by which the
nectar of flowers may be sucked, as in the butterflies.
ante7nna.......an.Ptenna-. --- -----------
BUG.
mouth-parts.                  mo-parts.                      MOTH.
antenna. -
i  antenna. --------------  O oFLY.
amoth-pars.  ------      BEETLE.
mnouth-parts.FIG. 55. —SHOWING MOUTIT-PARTS OF A FEW INSECTS.-THE HEADS ARE SEPARATED FROM
THE BODIES, AND ARE FACING THE LEFT, AND DRAWN IN PROFILE AS SEEN FROM THEIR
LEFT SIDES.
In the common house-fly, the mouth-parts appear as a
proboscis, a kind of fleshy appendage which is bent up when
not in use. When the fly feeds, the proboscis unbends, and




56               FIRST BOOK OF ZOOLOGY.
the food is lapped up by it.  Let the pupils carefully watch
a fly as it feeds upon a bit of sugar, or as it laps the hand.
In the butterfly and moth the pupil may uncoil the long
tongue with a pin. It resembles in appearance a watch-spring.
53. On the front of the head are two horns, or feelers,
called antenLce.
These are variously jointed, and vary greatly in different
insects.
In butterflies, they are generally long and slender, and
swollen at the tips, like a drum-stick.  Sometimes they are
thread like, and in others the antennme are barbed on the
sides, and look like a feather, as in certain moths. In some
beetles they are strongly jointed. In the common house-fly,
they hang down in front of the head.
Below are given figures of the left antenna of several
different insects showing how different they are in different
kinds of insects.  The pupils might save the antenne of
different insects and glue them to a card, writing opposite
each one the name of the insect, whether fly, beetle, or locust.
54. On the sides of the head are round, smooth places,
and these are the eyes. They are entirely different from the
eyes of most animals, for, when examined under the microscope, they are seen to be divided into little spaces, looking
very much like the surface of honey-comb. Each of these
little spaces represents a separate eye.  Some insects have
hundreds and. even thousands of these little spaces, or eyes.
For this reason, such kinds of eyes are called comppound eyes.
Under the microscope three minute black dots may be




PARTS OF AN  INSECT.                              57
seen on top of the head between the compound eyes, and
these are called simple eyes.
A          B   C   D   E    F   G   H  I
FIG. 56.-ANTENNiE OF VARIOUS KINDS OF INSECTS.
A, Fly.                     D, Dragon-fly.              G, Bug.
B, Bee.                     E, Moth,                    H, Beetle.
C, Green Grasshopper.       F, Butterfly.               I, Beetle.
In  many insects, as in  the  dragon-flies for example, the
compound eyes are very prominent and cover the sides of the
head, enabling the insect to look backward as well as forward.
A
C
FIG. 5T. —SnowIN  COMPOUND AND SIMPLE EYEs.
A, Head of Fly, natural size.
B, Head of Fly enlarged eight times; c, compound eye; s, simple eyes.
C, Portion of the surface of a compound eye highly magnified.




58               FIRST BOOK OF ZOOLOGY.
55. Thus far we have learned that an insect proper, or
true insect, has the body divided into three parts or regions,
called the head, the thorax, and the abdomen.
Let the pupil take a dead fly, and first pull off carefully
the legs and wings, and afterward separate the head from
the thorax, and the thorax from  the abdomen.  Having
separated the parts in this way, they may be pasted to a card
in this manner, writing the correct name beside each part, or
region, as shown in Fig. 58..... ——..
FIG. 58.-CARD, WITH REGIONS OF AN INSECT GLUED TO IT, AND MARKED.
The principal parts of the head are the mouth-parts, compound eyes, simple eyes, and antennae.
56. In studying the thorax, the pupil may select some
common insect (a large fly, or a bee, will answer the purpose), and pull off the head and abdomen.  A  common
house-fly separated in this way may be stuck upon a card.
By experimenting with a number of insects in this manner,
the pupil will soon learn that insects not only have the body
divided into three sections, but that the thorax invariably
has attached to it the legs and wings-the legs being at



PARTS OF AN INSECT.                        59
tached to the under side of the thorax, while the wings
are attached to the upper side thereof.
head. c,.
thora  _ ___. _
abdome.    — )
P5IG. 59.-Head, having mouth-parts, antenne, compound eyes, c; and simple eyes, s.
Thorax, having legs and wings.
Abdomen, never having legs or wings, but having certain appendages at the extremity.
57. The wings of insects are never more than four in
number, and these are arranged in two pairs.
The group of insects to which the house-fly belongs has
but two wings, or a single pair, and among this group (and
other groups of insects as well) there are some which have
no wings.
The wings are very different in shape and structure in
distinct kinds of insects.   In  the  common  fly  they  are
quite small, and transparent.  In  the butterflies they are
large and broad, and are covered with minute scales which
rub  off on the fingers like dust.   In the dragon-fly the
wings are long and narrow.




60                FIRST BOOK OF ZOOLOGY.
In all these wings the pupil will observe a net-work of
lines, which stiffen the wing and support the delicate memnbrane constituting the wing, just as the frame of a kite
stiffens and supports the paper that is stretched upon it.
These lines are called veins, or nervures.  To study the venaFIc. 60.-AN IN- FIG. 61.-AN INSECT WITH  FIG. 62.-AN INSECT WITH FOUR WINGS.
SECT WITHOUT   Two WINGS.
WINGS.
tion of the wings, is to study the way in which these veins
are arranged.  It would be well for the pupils to stick upon
a card a number of different kinds of wings, such as those
of the grasshoppers, beetles, flies, wasps, and label thema
accordingly.
58. In many insects the forward and hinder pair of wings
are of the same nature, as in the butterflies, moths, bees,
wasps, and dragon-flies. In other insects, however, the forward-wings differ in character from  the hind-wings.  Thus,
in the grasshopper the forward pair of wings are more
dense in structure than the hind-wings, though the little
veins may be seen closely crowded together. They differ as
well in form. (See Fig. 64.)
In other insects, as in the squash-bug, the front-wings




PARTS OF AN INSECT.                    61
have the half nearer the body dense and stiff, while the
remaining portion of the wing is very thin, or membranous.
In the beetles the front wings are hard throughout, and
in most of them  are bent and moulded to the shape of the
body, and, when closed, form  a tight cover over the hindwings.
The forward-wings of a beetle are so unlike ordinary
wings, that they are not called wings, but are known as
elytra, a single one being called an elytrom.
59. WVhen insects are at rest, they generally bring their
wings into a position different from  that taken by them  in
fligh-t.  In certain dragon-flies, however, the wings when
Butterfly at rest with wings
meeting over the back.
Moth at rest with the wings
sloping on the sides of the
body.
FIG. 63.-INSECTS AT REST.
at rest assume the same position as they do when flying.  In
the butterfly the wings are brought together over the back
when at rest, while the moths rest them  sloping over the
abdomen, the front-wings covering the hinder-wings.




62               FIRST BOOK OF ZOOLOGY.
In the grasshopper, the front-wings are long and narrow,
while the hind-wings are large and broad.  When the grasshopper is at rest, the hind-wings are folded together precisely like a fan, and, when closed, rest against the sides of
the abdomen, the long, narrow  front-wings closing down
upon them, and covering them.
60. Let the pupils prepare a grasshopper, with the wings
spread as in the act of flying. A specimen which is dry may
be moistened'by wrapping it np in a piece of wet cloth, and
letting it remain a day or two.
FIG. 64. —GEASSHOPPrE WrTHI THE WINGS OF ONE SIDE EXPANDED.-f, Forward-wing; h,
I-Iinder-wing.
Having softened the joints of the insect in this way, it
may then be pinned to a piece of cork, or a pin-cushion,
and, the wings having been stretched, they may be pinned
in this position, using triangular bits of card through which
the pins are passed to hold the wings in place, as represented
in Fig. 64, which shows a grasshopper with the wings on




PARTS OF AN INSECT.                      63
one side of the body pinned in the way described.. When
the insect becomes perfectly dry the wings will remain in
the position in which they were pinned.
A common beetle should be prepared in the same way.
In the beetle the front-wings are very hard and are
closed tightly over the hind-wings. With a pin, or the
blade of a knife, the upper or front wings may be opened,
and beneath these will be seen the hind-wings, not folded
like a fan as in the grasshopper, but folded or bent in the
middle, as the arm is bent at the elbow.
FIG. 65.-A BErETLE WITH THE ELYTRON AND HIND-WING OF THE RIGIT SIDE OPEN, AND THEM
ELYTRON OF THE LEFT SIDE OPEN WITH THE LEFT HIND-WING FOLDED IN ITs NATURAL
POSITION1 WHEN CLOSED.
61. The abdomen has no wings or legs, but is plainly
marked with lines running across the abdomen transversely.
VrG. 06. —ABDOMEN OF A DRAGON-FLY, SIOWING RINGS OR S0GDMUE F,




64               FIRST BOOK OF ZOOiLOGY.
These lines show the separation of the abdomen into rings,
or segments.  In insects with lengthened and slender abdomens the segments are long, and the abdomen, when bent
or curved, bends at these joints, as shown in Fig. 67.
FIG. 6T.-INSEOT WITI A LONG, SLENDER ABDOMEN.
If the pupil can handle these parts delicately enough,
he may be able to separate the abdomen at these joints
into a series of rings, or segments, and glue them on a card,
marked " Ringys or segments of the ccldomzen."  In the grasshoppers the segments show very plainly.  On the hinder
part of the abdomen there are various appendages, sometimes so short as to be scarcely perceptible, sometimes long,
and thread-like, as in the May-fly (Fig. 98); again, in the
shape of a sharp sting, as in the hornet. In the cricket, they
are quite long and conspicuous.  These appendages vary
greatly in different insects.




PARTS OF AN INSECT.                     65
CHAPTER IX.
PARTS OF AN INSECT (CONTINUED).
62. THE pupils have learned that the abdomen is divided
into rings or segments, and the division between these segments is plainly seen in most insects.
The thorax is divided in a similar manner, only the lines
which divide the thorax are not so plainly seen.
The nnmber of segments in the thorax is three.  To the
first segment, the head and first pair of legs are attached; to
the second segment, the second pair of legs and the first pair
of wings are attached; and to the third segment, the hind
pair of legs, the hind pair of wings, and the abdomen, are
attached. The three segments of the thorax have special
names: the prothorax, this being the forward segment, next
to the head; mesothorax, being the middle segment; and
nzetcatd orax, being the last segment.  Arranging these segments with the appendages attached to them in a table, they
would appear as follows:
(st Segent        (4othora~,   ~Has attached to it the first pair of
1 1st Segment, Protliorax,   lees.
TnE THORAX IS COM- 
POSErD OF THREE SEG-  2d Segment, Aiesothoraw,  Has attached to it the second pair of
~MEN~TS.~ ~I                     I  legs aend the first pair of wings.
rd SSegment,  fet(tl orax,  Has attached to it the third pair of
legs and the second pair of wings.
63. Let the pupils now endeavor to dissect a beetle, carefully separating the segments of the thorax, and, if possible,
the minute jaws and other mouth-parts, and stick them  on




66                    FIRST  BOOK  OF ZOOLOGY.
a large  card, with  the names of the  different parts neatly
marLed upon the card, as in  the accompanying figure (Fig.
68):
labi man.    --—. —.............................-._
maxilca. ----------------------------— J 
-...... - motlh-part,. 1
mandibleum. ------------------------------
an7,te?2nna. -1 
co irtu nleye.                      h..J —---— e a...     hecad.      J
first 7eg. a —-------------------               -      piora
elyt rf  -- --------------------- othioras 
uiing.
second leg. -------------- 
=_~il llu                 -m-~.-etathoraxE. J
second wiing. -
third le. --------------------
------------- _.BDOMEN.
FiG. 68.-A COMMON BROwN B[BEETLE,'WITH THE PARTS SEPARATED.
Having  now  learned  something  about the  parts of an
insect, and  having  seen  how  much  these parts vary in  size
and appearance in different insects, the pupils are better prepared  to  understand  the surprising  modification  which the
mouth-parts undergo in the different groups.
64. The parts of an  insect's mouth, generally speaking,
consist of an upper lip, called the  clabru /n; a pair of jaws,
called mancadibles; a pair of smaller jaws, called maxzillc, to
which are attached little jointed feelers, called maxillary




PARTS OF AN INSECT.                  67
2alpip; and a lower lip, called the lab6vin, which represents
still another pair of jaws joined together; to this joined
piece, or lacbium, are attached a pair of jointed feelers, called
labial pcaGl2i.  In Fig. 68 these parts are shown separated
from the head.
The numberless varieties of mouth-parts, peculiar to different insects, are in reality made up by modifications of the
parts above described.  Thus, in one group of insects, the
mandibles may be lengthened out into a piercing-like sting,
while some of the other parts may be reduced in size, or become almost obsolete. In another group the maxille may be
greatly elongated, with their edges joined to form  a tube,
while the other parts of the mouth are scarcely to be discerned.  In another group the labium may be greatly lengthened to form  a tongue-like organ for lapping up food, while
the mandibles-so big and hard in some insects-are barely
perceptible, and of no use to the insect.
Not only, then, do these parts assumne different proportions and different shapes in the different groups of insects,
but they also vary greatly in being very hard or very
soft.
If the pupils will examine the different kinds of insects'
wings, taking the front-pair of wings for example, they will
find a marked difference between them, some being very
large and transparant, as in the dragon-fly, others being hard
and opaque, as in the front wings or elytra of a beetle.
Compare the broad and brilliant-colored wing of the butterfly with the straight and narrow fore-wing of a common




68              FIRST BOOK OF ZOOLOGY.
grasshopper. And yet these are all wings. In a similar way
do the mouth-parts of an insect vary.
65. In the head of a mosquito, what appears to be a
single sting, by which the animal pierces the flesh and sucks
the blood, is in reality composed of long, delicate, threadlike parts, which represent the mandibles, maxille, and the
tongue, or ligta, which represents a prolongation of the'
labium. In the bugs the mouth-parts are compacted into a
hard beak-the piercer, so called, consisting of mandibles,
maxille, and labium, the labrum being represented by an
acutely triangular piece.
The mouth-parts of a beetle have already been described
in general terms. They are represented as separated from
the head in Fig. 68, while in Fig. 69 a side-view of another
beetle is given in which the mandible shows very prominently, while the labrum, labium, and maxillse, do not show
at all, as they are concealed by the other parts. The maxillary and labial palpi are seen, however.
66. In the butterfly the labial palpus is seen very large
and prominent, while the coiled, thread-like tongue represents
the pair of maxillhe lengthened and joined, forming a long
elastic tube which can be coiled or uncoiled by the insect,
and through which it sips the nectar of flowers. In the
mouth-parts of a house-fly the parts are soft and fleshy, and
united together to form a sort of proboscis; the maxille are
minute; the maxillary palpi are present as simple jointed appendages; the mandibles are minute, and useless; while the
labium is greatly developed, having a broad end which is




PARTS OF AN  INSECT.                          69
divided into two lobes at the extremity, by means of which
the fly laps up its liquid food. The insides of these lobes
are rough, and the irritation which flies produce when they
alight upon the hand is caused by the scratching of these
rough surfaces.
cantenna    > --
0       uSQUasa-Buca.
mandibles, 2nawilla, ancd [
labium, united.     --------------------
antenna - --
mandible. -------— BEETLE.
inaaillary palpus.
labiapalpu ------....... —
antenxna. -    o
antenna a. —---------------  HOurSErLY.
maccillarypalpus. —------------
labimn.
FIG. 69.-HEADS OF A FEW INSECTS SEEN FROM THE SIDE, 81IoWING MOUTH-PARTS, NAMED.
67:'. Much more may be learned about the mouth-parts of
insects, and the pupils might attempt the separation of the
mouth-parts of such inseets as the grasshopper, beetle, wasp,
and butterfly, sticking these parts, when separated, upon a
piece of white card, as shown in Fig. 68.




t0              FIRST BOOK OF ZOOLOGY.
It will be advisable,  also, for the pupils to utilize the
broken specimens of insects by selecting the wings of different insects and gluing them upon a card, labeling each
one. Different kinds of antenne might be fastened. upon
another card, and the legs of some widely-different insects
may be arranged in the same way. For example, let themn
take the hind-pair of legs of a grasshopper and of a waterbeetle. It will be instructive to observe how clifferent these
two kinds are, and how admirably one is adapted for jumping, while the other is so perfectly fitted for a paddle. IBy
making comparative collections of this kind the pupils will
learn a great deal regarding the structure of insects.
68. The pupils- have thus far learned that a true insect
has the body divided into regions called the head, thorax, and
abdomen; that the head bears the mouth-parts, antennse, and
eyes. The thorax has the legs and wings, while the abdomen
has only the caudal or tail appendages, and these are not
often apparent. They have also learned that the thorax is
made up of three segments, not often plainly marked, while
the abdomen is composed of a greater number of segments,
in most cases very plainly apparent. As each segment of
the thorax is characterized by having attached to it a pair of
appendages, and as the head contains a number of appendages, it is believed by many naturalists that an insect's head
is composed of a number of segments, so closely merged
together, however, as not to be distinguished, except theoretically. As naturalists, however, differ in their estimate of
the number, we will leave this difficult problem  for more
advanced students to study.




GROWTH  OF INSECTS.                         71
CHAPTER X.
GROWTH OF INSECTS.
69. As the study of the growth of an insect, from the
egg to maturity, requires some time and considerable care,
the different stages of such growth may be described and
taught with what examples the pupil may be able to collect.
An afternoon may be spent exclusively in collecting the
following objects:
A                        C
FIG. 0O.-EGGS: A, Eggs attached to Outside of a Cocoon
(B and Ccopied from figures by C. V. Riley).
FIG. I. —CATERPILLAR
AND GRUB-WORMS.
A
FIG. 73.-CocooNS' A, showing Inside of Cocoon, containFIG. 72.-CHRYsALIDES.        ing the Remains of a Chrysalis-Sklin.




72              FIRST BOOK OF ZOijLOGY.
In the spring and fall the eggs of the canimer-worm moth
may be found in abundance on fences and trees in cities.
They are very minute, and are found in clusters arranged
like stones in a pavement, but with greater regularity. With
a sharp knife a shaving of wood may be cut off, taking the
eggs with it. (See eggs in Fig. 77, b.)
If they are collected in the spring-time, little wornms will
hatch from them in the course of a few weeks, and these
nay be fed on the young leaves of the elm-tree.
Eggs of other insects may be found on fenees, leaves, and
twigs of plants; also on the leaves of the squash-vine, and
other plants in the garden.
Certain eggs may be found upon the twigs of apple-trees,
covered with. a shiny coating, like varnish. For all these objects the pupils will have to hunt carefully, as only the keen-.est eyes will find them out.
70. Caterpillars and g)'Ub-worms are found everywhere,
so common indeed that the pupil has only to examine the
fences as he goes to school to secure some. For certain
kinds of grub-worms, he may dig in the garden, follow
the furrow  made by a plough, or tear the bark from
some dead tree, and discover the specimens he is in search
of.  For chrysalides and cocoons the pupils may be directed to search on old garden-fences, under stones and dry
boards.
Some chrysalides will be found hanging with the large end
downward, as in Fig. 72; others will be found suspended
by the small end, with a delicate thread around the middle,




GROWTH OF INSECTS.                       73
holding the chrysalis horizontally, or vertically, against the
fence, as in Fig. 80, C.
Some of them  are encased in a mesh of threads, which
may be built against the fence, or under the edges of clapboards on the sides of houses.  And within the cocoons collected, the chrysalides, or their empty cases, will be found, as
in Fig. 73.
FIG. U4.-PORTION OF A FENCE, HArING -PON IT, AMON(G OTItER THINGS, EGGS, CATERPILLARSB
AND CHRYSALIDES OF INSECTS.
Rich collecting-places may always be found on old gardenfences in cities and towns.  Fences surrounded by trees and
bushes will oftentimes have a great many insects lurking
under projecting edges-caterpillars climbing up the posts,
4




74                FIRST BOOK OF ZOOLOGY.
and chrysalides attached to the rails of the fence. Fig.'74
shows a portion of a fence of this kind.
With the eggs, caterpillars, and chrysalides on hand, the
pupils are ready to study the life-history of an insect.
71. Many animals, as fishes, snakes, and birds, lay eggs,
and from  these eggs little creatures are hatched that reseinble the animals which laid the eggs.
Insects also lay eggs, but from these eggs come little
creatures which do not at all resemble the insect that produced them.
The different kinds of eggs collected by the pupils were
laid by insects of different kinds.  For example, if they have
collected eggs like the following (Fig.'5), the insect that laid
them was a moth, and looked like Fig. T6.
FIG. 7T6.-IWSEICT WHTCH LAID THE EGGS IN
FIG. 75.
FIG. 75.-EGGS LAID ON THE
TwIG OF AN APPLE-TREE.
Now, if the pupil will keep these eggs in a box, there
will hatch from  them little animals resembling worms, very
tiny at first, but growing rapidly if supplied with appropriate




GROWTH OF INSECTS.                        75
food. Insects generally lay their eggs in such places that
the worm, or caterpillar, coming from them can easily find
access to its proper food, and this food in the case of most
caterpillars consists of leaves, or the wood, bark, or juices, of
plants and trees.
72. Commencing with the egg, the pupil should get, if
possible, the insect while in the act of depositing her eggs,
and this will not be difficult to do in the case of the cankerworm  moth, whose caterpillars commit such ravages upon
the elm-trees.
b    a               c         d
e               YI  f           7A
FiG. 7.-CATNER —WORM MOTH, EGGS, AND WORmS: a, Female Canker-worm Moth laying
her Eggs, b; c, Top-View, and d, Side-View of an Egg magnified; e, Canker-worm eating its way out of the Egg, magnified; f Magnified Vievw of Canker-worm; g, Natural
Size of Canker-worm after leaving the Egg; h, Male Canker-worm Moth.
The female of the canker-worm  moth  has no wings.
They are very common in early spring and in the fall, laying their eggs on fences.  Fig. 77, ca, represents the female
moth depositing the eggs; b, the eggs being deposited upon
a chip which was cut from  a fence while the female was at
work; c, represents a top view of one egg magnified; d,




E6              FIRST BOOK OF ZOOLOGY.
represents a side-view of the same egg; e, represents another
egg with the canker-worm eating its way out; f, represents
the canker-worm highly magnified, after it has crawled out
from the egg; g, shows the natural size of the worm; A,
shows the appearance of the male canker-worm moth. The
female moth which is laying the eggs differs from the
male in having no wings.
Now, if fresh elm-leaves are placed in the box with the
worms, they will commence to feed on them. The eggs
hatch out just as the leaves commence to grow, and consequently the young worms have tender leaves to feed on
at the outset.
The worm grows rapidly, and after a few weeks ceases
feeding, and, dropping to the ground, or lowering itself down
by a thread spun from the head, buries itself just below the
surface of the ground, and there changes into a chrysalis, forming a rude cocoon of earth about it. At the proper time
there comes from the chrysalis a male canker-worm moth
with wings, or a female canker-worm moth without wings.
V3. From  the eggs, then, come worms or caterpillars.
The worms or caterpillars change into chrysalides, and sometimes these are inclosed in cases or cocoons. From the chrysalides comes the perfect insect, similar to the insects which
first laid the eggs.
If it is desired to keep the caterpillars alive, the pupil
should try to find them when they are feeding, and to observe the kind of leaf they are eating, and then, by giving
them fresh leaves of the same kind as they need them, the




GROWTH OF INSECTS.                      77
caterpillars will grow  rapidly, and ultimately change into
chrysalides.  It is a common thing to see boys collect caterpillars and place them in a box, with grass to feed upon; the
grass dries, and of course becomes unfit for food, and even
if it were fresh the caterpillar would not eat it, unless it were
its natural food.  If the pupils wish to raise caterpillars,
they must be sure and furnish them with the kind of leaf
they are accustomed to feed upon.  It may be an elm-leaf,
or a cabbage-leaf.   Thus, there is a common worm  which
they will find feeding on the leaves of the Tartarian honeysuckle, as in Fig. 78.  To raise this worm, therefore, it is
necessary to furnish it, from time to time, with the leaves of
this honeysuckle.
FIG. T8.-WORAi FEEDING ON THE LEAF OF TEIE TARTARIAN I-IONEYSUCKLE.
(Copied from figure by J. H. Emerton, in Packard's " Guide to the Study of Insects.")
In its growth, the caterpillar usually sheds its skin three
or four times.
After the caterpillar has become full-grown, it stops eating, and crawls about in a restless manner.




78               PFIRST BOOK OF ZOOLOGY.
In the summer and fall, various kinds of caterpillars are
seen crawling over the sidewalks and along fences.  They
are not now searching for food, but are seeking an appropriate place where they can change into the chrysalis state.
From the long, active, and often devastating caterpillar,
having three pairs of small legs in front, and other pairs of
blunter legs behind, the creature gradually changes into a
body, blunt in front, tapering behind, with no indications of
legs, head, or any of the appearances seen in the caterpillar,
except that the hinder part still shows the division of that
portion into rings or segments as in the caterpillar, and signs
of life are still manifested by this portion moving from side
to side, when touched. Many caterpillars spin a case or cocoon, as it is called, in which it incloses itself previous to
changing to a chrysalis.  The thread with which they make.
this case issues from  a little tube in the lower part of the
mouth or labium.  Silk is made from  the thread composing
the silk-worm's cocoon.
A             B           O
FIG. 79.-A, Hinder Portion of Chrysalis-skin hanging; B, C, Enlarged View of Hinder End,
to show the little Hooks by which it hangs.
74. Fig. 79, A, shows the hinder portion of a chrysalisskin, the insect having escaped from it, and the forward part




GROWTH OF INSECTS.                       79
having fallen to the ground.  The chrysalis is seen suspended
by the tail, and is held there by little hooks on the end of
the tail, which become entangled in a sort of web previously
made by the caterpillar; _B  and C represent different -views
of the chrysalis-tail enlarged so as to show the hooks. Pupils
will be sure to find these empty chrysalis-skins attached under the projecting portions of fences.
A                               B    b
C                              D
FIG. 80. —A, Caterpillar getting ready -to change into a Chrysalis; B, Just ready to shed its
Skin previous to changing; b, little Band to hold it up; C, Chrysalis; D, Butterfly just
escaping from Chrysalis, the Wings just being unfolded.
Fig. 80 shows different stages of a cabbage-worm, from
the worm stage to the chrysalis stage: A, representing the
worm  as it assumes a position under the projecting edge of
a fence; B, after it has supported itself round the body by a
delicate thread, b, and attached itself by the tail at the same
time; and, C, representing its complete chrysalis condition;
D, shows the butterfly just escaping from  the chrysalis, the
wvings still being rumpled.  After having escaped from  the
chrysalis, the butterfly generally clings to the empty case till
the wings have expanded and dried, when it flies away.
Fig. 80 represents a cabbage-butterfly introduced from  Eu



80              FIRST BOOK OF ZOOLOGY.
rope, and now common in certain parts of New England. Its
wings are yellow, with two blackish spots on the forward
wing, and one on the hinder wing. The chrysalides of this
species are very common on fences, and, when collected in
the fall, may be kept through the winter. During February
and March the butterflies will come out, and these may be
fed on honey or sugar mixed with water, and in this way
may be kept alive for some time.
75. The caterpillar, then, having changed into the chrysalis, remains in this condition a few weeks, or even many
months, and then the skin slowly cracks open, and out crawls
a creature no longer like a caterpillar, but having three pairs
of long, jointed legs, the body divided into three very distinct
regions-the head, thorax, and abdomen-the thorax having
wings, and the head furnished with long antennme, and provided with imouth-parts suitable for sipping nectar, and no
longer like the heavy jaws of the caterpillar, suited only to
chewing coarse leaves; in short, a creature resembling the
insect which first laid the eggs from which the caterpillar
came.
T6. Other names are given to these three stages of an
insect. The worm, or caterpillar, is called the lcarva; the
chrysalis is called thepcupa; while the perfect insect is called
the imzcyqo.  These terms are necessary, for without them
the proper condition of an insect could not be easily described.
Take, for example, the caterpillar stage of a butterfly:
the same stage in a common fly is known by the name of




GROWTH OF INSECTS.                      81
maggot, and in other insects the same conditions are known
by the name of borer, grub-worm, and many other terms.  If
thle pupil learns that all these various names describe a similar stage in the lives of these insects, it is much more convenient to have some general term describing all these stages,
such as larva, or larval stage.'7. While most insects pass through changes similar to
those above described, there are others, such as the grasshoppers, crickets, roaches, and bugs proper (a group of insects which includes the squash-bug, lchinch-bug,   and bedbug, all of which have a disagreeable taste and odor, and
to which naturalists restrict the name of bug), which do not
pass through a caterpillar and chrysalis state.  The young
hatch from  the egg, and closely resemble the adult insects
a    b
FIG. 81.-DIFFERENT STAGrES OF THIE CHINCH-BUG: a, Egg; b, Newly-hatched Larva; c, Larva
after First Moult; c, Larva after Second Moult; e, Pupa; f, Perfect Insect.
[These figures are copied from the Seventh Annual Report of C. V. RILEY,
State Entomologist of Missouri.]
except that it has no wings, and is of course much smaller
than the parent.  In its growth it moults or sheds its skin,
and each moult reveals its wings more advanced in growth,




82PI             FIRST BOOK OF ZOLOGY.
till finally, on the last rmoult% it attains the size and features
of the mature insect.  And even in this growth, so unlike
the moth and butterfly, the terms larva and pupa are applied
to certain stages of their history.
The foregoing figure represents the egg and successive
stages of the chinch-bug, an insect which has been so destructive to various crops in the West. The figures are all
enlarged; the little line at the lower left-hand side of each
figure represents the natural size.
78. Many insects, as the beetles, flies, moths, butterflies,
bees, and wasps, pass through complete and distinct changes
from  their early condition to maturity, as above described.
Other insects, as the grasshoppers, crickets, roaches, and
bugs, hatch out from  the egg, as little six-footed insects,
and not as worms, and in their growth do not pass through
an inactive puyla or chrysalis stage, but slowly acquire wings,
and ultimately attain full growth as above stated. I-Ience
these changes are not so completely defined as the changes in
the insects first mentioned.  For this reason the term  comnylete 9netamzorphosi8 is used to define the mode of growth of
the beetles, flies, and other insects having a similar mode of
growth; while the term  inconplete mnetano2phAosis defines
the mode of growth of the grasshoppers, crickets, and others.
79. Many of the larvae of insects look like worms —so
much so, indeed, that they are commonly called worms, such
as cut-worms, canker-worms, currant-worms, and the like.
The pupils have learned that these are not true worms, but
only the larval condition of certain insects.




GROWTH OF INSECTS.                   83
True worms, however, never change into any thing else.
Such, for example, is the earthworm, hair-worm, and leech,
and worms which live in the sea.
FIG. 82.-EARTHWORM.
FIGe. S3. —MARINE WORM.
These worms, and other true worms, generally speaking,
have the body divided into a great many segments or rings,
as in the earthworm.  In the larva of insects, on the contrary, the segments are limited in number.  With few exceptions the larvae of insects have legs, and these legs in the
fore-part of the body are jointed.  In worms, jointed legs do
not occur. The jointed legs of the larvTe number three pairs,
and are on the three successive rings back of the head, and
consequently correspond to the three pairs of legs in the adult
insect.
In certain larvae other legs occur, but these are not jointed,
though often having special structures at their extremities,




84              FIRST BOOK OF ZOOLOGY.
by which they are enabled to cling. These are called proplegs, or false legs.
It would be well for the pupils to collect some leeches and
earthworms, and, if they live near the sea-shore, a few worms
may be collected under stones at low tide.
Having collected these, let the pupils compare them with
the larve of insects.
As the larva of an insect comes from the egg, it has its
full number of segments at the outset.  In the larva of a
butterfly, for example, there may be counted, besides the head,
twelve segments or rings, and this number does not increase
as the creature grows, but remains constant; and, as we have
already learned, the creature does not long remain in its
worm-like stage, but assumes' other conditions, ultimately becoming a creature unlike, in form and habits, the larval condlition in which it spent a portion of its ]ife.
80. The true worm, on the contrary, comes from the egg
with a very limited number of segments, and as it grows
new segments are formed, till in some worms as many as
four or five hundred segments are developed before the animal has attained mature proportions, and in this condition
it remains; that is, it is complete, never changing or passing
through larval or pupal stages to develop into something
quite unlike the worm.
TBriefly, then, a larva may be distinguished from a true
worm generally by its limited number of segments, and, when
supplied with legs, having three pairs of jointed ones on
the anterior rings of the body.




HABITS AND STRUCTURE OF INSECTS.           85
With few exceptions worms live in the water, and even
those which live on the land are limited to damp earth or
moist places. While the larve of insects are in many cases
aquatic in their habits, and breathe or respire by means of
gills, the larger number live on the land, feeding on leaves,
wood, and substances of a similar nature, and are airbreathers.
CHAPTER XI.
HABITS AND STRUCTURE OF INSECTS.
81. LET the pupils now endeavor to study the habits of
certain insects by direct observation.  The following sketches
are given as aids to the pupils in making independent observations on special insects.
Most insects make no provision for the larva, but leave
them to take care of themselves, though usually the egg is
deposited where the larva comling from it may find proper
food at hand.
Other insects prepare cells or cavities in which they deposit their eggos, just as a bird builds a nest to hold its eggs.
Certain insects, in preparing these cells, also lay up a store of
food ready for the larva when it shall have hatched from the
egg. Such is the case with the common mud-wasp.  This
insect makes a number of little chambers of mud, generally
sticking them to the sides of a wall, or to the ceilings of sheds,
barns, and attics. These pellets of mud are seen firmly plas



86               FIRST BOOK OF ZOOLOGY.
tered to the wall, rough and irregular in appearance, and at
first sight might be mistaken for the work of some mischievous boy.
FIG. 84.-A MUD-WASP'S NEST, HAVING Two CELLS.
Fig. 84 represents their general appearance, for, rough
as they appear, on close examination they are seen to be
constructed very systematically - the soft clay of which
they are built being laid on in alternate layers, looking
something like a braid; while the upper portion, being built
of looser and coarser material, is put on ill irregular lumps.
With a thin-bladed knife these mud-cells may be scraped off,
and sometimes can be pulled away with the fingers.  Upon
opening them  they will be found either filled with little
spiders, or containing yellow-colored larvae, pupae in brown
skins, or wasps.  Their history is as follows:
82. When the mother-wasp gets ready to lay her eggs,
she first builds these curious nests of mud, which she collects
from the streets, or by the sides of brooks in clayey soil. Having finished one cell, she deposits therein an egg, and then
collects a number of small spiders with which she completely
fills the cell. After this is done she closes up the top of the




HABITS AND STRUCTURE OF INSECTS.                  87
cell with looser mud. Thus she proceeds, constructing cell
after cell, going through the same manceuvres with each one.
It has been observed that the wasp stings the spiders so
as to paralyze, but not to kill them.  Hence they remain
alive but cannot struggle, and when the egg hatches the
little  larva coming from  it finds in these spiders a store
of food on which to feed.  These are gradually eaten, and
thus room is made for the rapidly-growing larva which, having eaten all the spiders, passes into its pupa state surrounded
by its brown chrysalis case, and finally emerges a perfect
wasp, when it softens the mud-walls of its nest, by a fluid
poured from its mouth, and gnaws its way out.
C    d    b   a
FIG. M5.-SHOWING A NEST OF FOUIs CELLS CUT OPEN: a, representing a Cell with the Egg
at the Bottom, and the remaining Space filled with Spiders; b, the Larva full-grown,
after having consumed all the Spiders; c, the Pupa; and d, the Imago, or Perfect
Wasp, ready to come out.
Fig. 51 shows one of these mud-wasps pinned.
The pupils may collect these nests or cells in April or:May, and by June the wasps will be ready to come out. If
collected soon after they are made, the eggs may be found; if




88                   FIRST BOOK  OF ZOOLOGY.
a little later, the larva will be found feeding on the spiders;
and, still later, the full-grown larvoe and pupoe appear.
In collecting for the cabinet, one nest should be cut open
to show the cells and their contents.
83. The mosquito deposits her eggs on the surface of the
water, sticking them  together in such a way as to form  a
raft.   From  these eggs little black  creatures hatch, which
swim  about with a quick, jerking motion.  In this condition
they represent the larvae.  If the pupils will examine pools
and ditches, or even the tubs and barrels of water which often
stand about farm-houses, they will be very sure to find some
of these animals.  They are small and  black, and by their
C
A              B
FIG. 86.-A, Larva; and B, Pupa of a Mosquito; c, Line showing Natural Size of Larva; d,
representing Water-Line. —The larva is seen with the hinder end of the body just projecting above the surface of the water, so that the air may enter through the little tube.
The pupa is seen with the back just level with the surface of the water, and through the
two tubes, on the back of the thorax, the air is being admitted to the body.
rapid, jerking motion cannot be mistaken. A number may
be collected and placed  in  a jar of water, where all their
changes, from  the larval to the perfect state, may be watched.
They will be seen coming to tile surface of the water for air,




HABITS AND STRUCTURE OF INSECTS.           89
which they breathe in through openings in the hinder part
of the body. Changes soon take place by which they assume the pupa state, and at this time they no longer breathe
through the hinder portion of the body, but through two
tubes on the back of the thorax. Finally, the pupal skin cracks
open, and out crawls the perfect mosquito, for a while resting on the empty pupal case which floats in the water like
a raft, and the insect remains supported in this way till the
wings become fully expanded and dry, when it flies away.
CHAPTER  XII.
HIABITS AND STRUCTURE OF INSECTS (CONTINUED).
84. IN certain groups of insects the young hatches from
the egg, not as a caterpillar, but as a little insect having the
body divided into three regions, possessing three pairs of
jointed legs, and looking very much like the mature insect,
except that it is very much smaller and has no wings.
FIG. 87.-YounG GRASSHOPPER. —w, Wing just appearing.
In the grasshopper, for example, the animal does not pass
through a series of abrupt changes, but the creature comes
from the egg with the general proportion of the adult insect,




90                  FIRST BOOK OF ZOOLOGY.
save that it has no wings, these growing gradually as the
creature increases in age.  Fig. 87 represents a young grasshopper with the wings just appearing. At intervals, the insect sheds its skin, or noullts, the wings continually increasing in length until mature size is reached.
Let the pupils endeavor to collect some young grasshoppers representing various stages of growth, and place these
in their collections beside the full-grown one.
By searching in the grass, the cast-off skins of grasshoppers may be occasionally found still clinging to the spears of
grass, where they were left when the grasshoppers shed themn.
FIG. 88.-CAST-OFF SKIN OF A GRASSHOPPER.-The grasshopper has shed its skin whilo
clinging to a blade of grass. The skin is imperfect, the antennae and parts of its legs are
broken; the abdomen is shriveled, and does not show.




HABITS AND STRUCTURE OF INSECTS.             91
Fig. 88 shows the appearance of one of these cast-off skins.
85. Grasshoppers are often infested with parasites. Frequently the grasshoppers, in a sickly condition, are met with
clinging to the grass, or bushes. A careful examination of
them will show a number of little bright-red mites crawling
on them, or attached near the base of the wings, and evidently the cause of their weakness.
Curious cases have been found wherein these creatures
had met with fatal accidents. In their headlong fall to the
FIG. 89.-GRASSHOPPER PIERCED WITH SPEAR OF GRASS.
ground, after one of their reckless jumps, they are liable to
have their armor pierced with the dried spears of grass. Fig.
89 represents a grasshopper which had been pierced in this




92                  FIRST BOOK OF ZOOLOGY.
way, the dried point of the grass probably striking the head,
and then glancing off, and entering between the head and
the thorax.
86. In studying the early stages of the mosquito, it was
found that at the outset the animal breathed air through an
opening in the hinder part of the body; that soon after this
the opening closed, and air was taken in by two openings on
the back, but in no case did the insect breathe through its
mouth.  In the perfect insect, as well as in most larva, there
are little openings along the sides of the body. These little
openings communicate with  tubes which branch, and subdivide again and  again, sending  their little  air-twigs into
every part of the body, even into the legs and the veins of
the wings. These little tubes represent the lungs of an insect. They necessarily render the body very light besides.
to
FIG. 90.-INsEcT SHOWING THE SPIRACLES.-Grasshopper with the wings and two hinder pairs
of legs removed to show spiracles, or openings in the sides of the body which communicate with the air-tubes within the body:'w, showing where the wings were attached;
h and m, where hind and middle legs were attached; s, spiracle on thorax; t, tympanum.
In large insects like the grasshopper the minute openings
in the sides of the body can be plainly seen without the aid
of a glass. The segments of the abdomen have each a little




HABITS AND STRUCTURE OF INSECTS.           93
opening, which is represented in the figure; and where the
abdomen joins the thorax, a cavity lined with a delicate skin
will be found, which is called the tymnpctnanan, and is supposed
to be an organ of hearing.  If the softer parts within the
body of an insect be removed and slightly compressed between two pieces of thin glass, the air-tibes, looking like fine
white threads, may be seen with an ordinary pocket-lens.
The air-tubes are called trachece, and the openings on the
outside of the body which communicate with them are called
spiracees.
87. Insects breathe by dilating and contracting the abdominal segments. The act of breathing can be plainly seen
in the grasshopper or the honey-bee, and it will be noticed
that after violent exercise, as in a long flight, the insect
breathes more rapidly than when it has been at rest for some
time, just as a boy after running finds himself compelled to
breathe rapidly for a while.
After violent exercise the insect gets tired and rests. Bees
may often be seen, after a long flight, to alight in the grass
near a flower, and for a while appear so fatigued that they
cannot reach the flower, but remain breathing very rapidly.
Insects have curions ways of resting and sleeping. A species
of wasp has been observed soundly sleeping while holding on
to a blade of grass by its jaws alone, the fore-legs just touching the grass, while the body and the middle and hinder
pair of legs were hanging downward, and not bearing against
the grass at all, as shown in Fig. 91.
88. In this connection it may be well to allude briefly to




94               FIRST BOOK OF ZOOLOGY.
the manner in which the various sounds emitted by insects
are made. It is obvious that the vibration of the wings produces the loud buzzing sound made by certain insects. But
there are other sounds which are traced directly to the
effect of the air rushing in and out of the spiracles, and
impinging on certain plates whose sharp edges border the
spiracle.  The experiment has been made of closing the
FIG. 91. —WASP SLEEPING WHILE HOLDING ON TO A BLADE OF GRASS WITH ITS JAWS.
spiracles with varnish, when all noise ceased. It is believed
that the mosquito produces its remarkable tones in this way.
Such noises have always been associated with the vibration
of the wings, because the noise seems to be made when the
insect is flying, but the cause of this is explained by supposing that the violent muscular action of moving the wings
also causes the air to be violently thrown out of the spiracles,
and as a proof of this it has been found that cutting off the




HABITS AND STRUCTURE OF INSECTS.          95
wings of such an insect, while modifying the sound, by no
means prevented it being made; and it is a fact also that no
sound is produced by other insects whose wings vibrate with
great energy.
89. The peculiar chirp of the cricket is made by the forewings being rubbed rapidly against the hind-wings upon
which they rest; one of the large veins in the fore-wing
being thickened and notched like a file, and the wing itself
acting as a resonant body in augmenting the sound. The
males, only, make this sound; the females are silent; and if
the fore-wing of the female be examined, the vein in question is not thickened, nor is it rough, like a file.
MLr.'Samuel H. Scudder has stated that the grasshoppers produce their sound, or stridulate, in four different
ways: "1. By rubbing the base of one wing-cover upon
the other, using for that purpose the veins running through
the middle portion of the wing; 2. By a similar method, but
using the veins of the inner part of the wing; 3. By rubbing the inner surface of the hind-legs against the outer surface of the wing-covers; and 4. By rubbing together the
upper surface of the front edge of the wings and the under
surface of the wing-covers.  The insects which employ the
fourth method stridulate during flight-the others while at
rest. To the first group belong the crickets; to the second,
the green or long-horned grasshoppers; to the third and
fourth, certain kinds of short-horned or jumping grasshoppers."
90. Harris, in describing the third method of stridulation,




96                 FIRST BOOK OF ZOOLOGY.
says that " their instruments may rather be likened to violins, their hind-legs being the bows, and the projecting edge
of the wing-covers the strings," and adds that when a grasshopper begins to play "he bends the shank of one hind-leg
beneath the thigh, where it is lodged in a furrow designed
to receive it, and then draws the leg briskly up and down
several times against the projecting lateral edge and veins of
the wing-cover.  He does not play both fiddles together, but
alternately, for a little time, first upon one, and then on the
other, standing meanwhile upon the four anterior legs and
the hind-leg which is not employed."
b ae>\ ohb eoooosooeo
c Cubb  > b b zo o0 0 e  e  0alg
FIG. 92.-Leg of a Grasshopper magnified, showing Ridge of Fine Teeth on the Inside of the
Leg, marked a, by which the Insect rasps the Wing; b, c, Different Views of Ridge of
Fine Teeth, highly magnified.
A figure is here given of the hind-leg of a common grasshopper, showing the row of minute teeth which occur on the
inside of the leg, and which are drawn across the edge of the
wing.  The pupils may imitate the sound thus produced by
drawing a coarse file, or the teeth of a comb, rapidly across
the edge of a stiff sheet of paper.




HABITS AND STRUCTURE OF INSECTS.           97
CHAPTER  XIII.
HABITS AND STRUCTURE OF INSECTS (CONTINUED).
91. A LITTLE bug, called the tree-hopper, has a peculiar
history in its young state.  The eggs of certain species are
laid in the ground, and, as soon as these hatch, the young
ones crawl up the stems of grass, and, piercing the grass with
their mouth-parts, commence to suck the juices contained
therein.  While this action is going on, a clear, watery fluid
escapes from certain pores in the body, and in a short time
the young insect is completely immersed in it.  As it is
obliged to breathe air, it secures this by turning up the
hinder part of the body, and by means of little appendages,
clasping a bubble of air, which then flows along the under
side of the abdomen; here it is taken in through the spiracles. The air having been so nsed, is allowed to escape in
the fluid in which the insect is immersed.  This operation
is repeated over and over again fresh bubbles of air being
thus secured, and then escaping in the fluid. After a while
the fluid becomes filled with these little bubbles, which soon
convert it into a frothy substance, and this is the origin of
the white flecks which occur so thickly on grass, and which
is here commonly called frog-st)it, and, in England, ccfckoospittle.
92. There are certain insects belonging to the same group
which are aquatic, and whose young come to the surface of
5




98                      FIRST BOOK OF ZOOLOGY.
the water, and  in the same manner seenre air.   So this little
tree-hopper, while in the  young  state  sucking  the  juices of'
grass, and completely immersed in a watery fluid, may be
looked upon as an aquatic larva  during this stage.
FIG. 93.-GRASS, WITH TIIE FROTH    FIG. 94.-A PORTION OF A GRASS-STEM, WITH TIIE
UPON IT, a, a, and a Young In-     YOUNG INSECTS,,1AGNIFIED: a, the Insect reachsect exposed at b.                 ing out the Hinder Part of the Body to secure
a Bubble of Air; b, an Insect allowing a 13ubble of Air to escape in the Fluid, the dotted line
b indicates the bubble; c, the Mouth- parts, like
a Sting, piercing the Grass.
Let the   pupils collect and   examine  this  froth, and, by
carefully wiping  it away, they  may  expose the young insect
fastened to the grass.
93. The insect called the seventeen-year cicada, or seven



HABITS AND STRUCTURE OF INSECTS.            99
teen year locust as it is improperly called, has an interesting
life-history.
The perfect insect is shown in Fig. 95.  They may be
known by the peculiar loud, buzzing sound emitted by the
male. This sound can oftentimes be heard at a great distance.
FIG. 95.-SEVENTEEN-YEAR CICADA.
The seventeen-year cicada is found rarely in Southern
New England, but is common in the Southern and Western
States.  This species exists in great numbers, and does
immense damage to the trees which it infests. The female
deposits her eggs in the twigs and smaller branches of
oaks. Little furrows are made in the twig, side by side, and
into these furrows the eggs are laid.  The leaves wither
on the trees from the injuries inflicted in this way. Little insects hatch from the eggs, entirely different in appearance from the parent; and these, running to the end of the
twig, fling themselves off, and falling to the ground dig
their way down, till they come to some root upon which
they fasten, and with a piercing sting suck the juices of
the root.  Here they remain for nearly seventeen years,
slowly growing. At the end of that time they assume the




100               FIRST BOOK OF ZOOLOGY.
appearance represented in Fig. 96.  At the proper time they
crawl out of the ground, and their skins splitting open along
the back, out come the perfect insects, with wings and all
complete, to fly away, lay their eggs, and devastate the
forests.
There are certain species which do not occur in such
numbers, and which pass through all their changes in a single year.  The cast-off skins of the pupa of such species may
be often found clinging to apple-trees and fences in New
England.
FiG. 96.-PUPA-CASE OF A SPECIES OF NEW ENGLAND CICADA OR HARVEST-FLY, CLINGING
TO A TWIG.
The pupils should, if possible, collect a twig in which
the eggs have- been deposited, a pupa-skin, and the perfect
insect.




HABITS AND STRUCTURE OF INSECTS.               101
CHAPTER XIV.
ITABITS AND STRUCTURE OF INSECTS (CONCLUDED).
94. THE May-fly, or EpiLemerac is one of the most common insects in the Western States.  They live only a few
weeks in their perfect state, oftentimes but a few days.
Their eggs are laid in the water, and the larvse live in the
water two or three years.  At the end of this time they
come to the surface in immense numbers, and, shedding
their skins, come out as winged insects. At this time they
resemble their perfect state so closely, that the name subFIG. 97.- LARVA or EPIIEmIEA.
(Reduced from Figure by J. H. Emerton, in Dr. A. S. Packard's Directions for collecting
Insects, Smithsonian Institution.)
imagos is given to them  in this condition.  They often fly
a considerable distance from  the water, alighting on the
ground and trees.  Here they again shed their skin, and
then have attained their perfect state.




102              FIRST BOOK OF ZOOLOGY.
These insects occur in prodigious numbers in certain
parts of the world.  In some regions of Europe they are so
FIG. 9S.-EPHEMERA.
abundant that the inhabitants collect them in heaps, and use
them as dressing for the land.  In the cities bordering the




HABITS AND STRUCTURE OF INSECTS.           103
great lakes it is a common sight to see the gas-posts and
adjoining buildings blackened by the myriads of Ephemera
which have been blown in from the lakes and have been attracted by the lights.  The following figure represents a
gas-post, in Cleveland, Ohio, as it appeared with Ephemera
clinging to it:
FIG. 99. —GAS-POST, WITHI EPHEMERA CLINGING TO IT.
95. Another group of insects somewhat resembling the
Ephemera pass their larval state in the water.
Some of their larvse are called ccaddcis-worms, or case



104               FIRST BOOK OF ZOOLOGY.
worms, and are inclosed in cases of cylindrical and other
shapes.  These are variously made of grains of sand, bits
of bark and sticks, and other fragments of convenient size
cemented together.  Some of these cases, built of small
FIG. 100.-C-ADDIS-WORM, WTITH  CASE.
grains of sand, look like coiled snail-shells.  Other larva
shelter themselves in bits of straw, or the fragments of
hollow stems of plants.
Fig. 100 represents the larva of one of these insects in
its case, which is made of bits of sticks arranged in a spiral
course.  The larva drags about this case, and as it grows collects material for the enlargement of its tube.
In almost any quiet pool or running stream these curious
cases may be found, containing the larvwe within.
FIG. 101.-GALL-FLY.
96. The curious round balls called gall-nuts, which are
Ibund on the leaves of the oak and of other trees, are produced by an insect called the gall-fly.'The eggs are deposited in the substance of the leaf, and




HABITS AND STRUCTURE OF INSECTS.            105
it may be that the larva, by its presence there, causes the
unnatural growth of the leaf, resulting in a wart or tumor,
and sometimes in a large round nut. It is believed, however,
that the adult insect, in depositing the egg, also stings the
leaf, and, poisoning it at the same time, induces the abnormal growth of the leaf.  Within this the larva feeds,
N. —  W
FIG. 102.-GAIT -NUT ON OAK-LEAF.
(Copied from Harris's "Insects injurious to vegetation," third edition.)
and changes into the pupa state, and finally into the perfeet
insect, when it gnaws its way out.
In the autumn the pupils will find the gall-nuts abundantly in the woods.  Let them collect a number of these,
andl, on carefully cutting them open, they will find within a
tiny oval case, and upon opening this they will discover
snugly stowed away a little, polished black fly having four
wings.  Tilhe creature when liberated is ready to fly away.




106              FIRST BOOK OF ZO6LOGY.
Some of the nuts will be empty, because the gall-insects
have already escaped.
Galls are also produced by insects not at all like the ichneumon.  The following figure, which represents a gall conmon on the golden-rod, is produced by a two-winged fly.
The figure represents the stem or stalk unnaturally swollen,
the swollen portion being the gall, within which the larva,
pupa, or perfect insect, may be found if- the creature has not
already escaped.
Fro. 103.-GALL ON GOLDEN-RIOD STALK.-P, Pupa removed from the Gail.
Let the pupils arrange in their collecting-box a leaf with
the nut attached, a nut cut open showing the pupa-case, and
the insect pinned.
97. Only a few brief lessons have been given representing the life-history of a butterfly, mud-wasp, mosquito, spit



HABITS AND STRUCTURE OF INSECTS.          107
tie-insect, seventeen-year cicada, May-fly, and gall-fly.  Let
the pupils endeavor from  their own observations to make
additional life-histories, or record facts, concerning other
insects, such as the honey-bee, paper-wasp, and a great many
other common insects, of which no mention has been made
here. The turning over of stones and logs in the woods
will oftentimes expose the burrows of ants, and the ants
will probably be found busily engaged in carrying off long,
white, oval cases, which look like eggs; let the pupils collect
some of these, and see if they can find out what stage in the
history of the insect they represent.
98. An instinct which appears wonderful to us, prompts
the insect to seek appropriate places for the deposition of
her eggs.  The butterfly, for example, seeks for food
the nectar of flowers; its larvse, however, must have
leaves upon which to feed, and the instinct of the butterfly
impels it to deposit its eggs in a place where the young
shall find their appropriate food.  It has been learned
also that other. insects store up animal food for their
young, as in the case of the mud-wasp, where spiders are
imprisoned in cells in which the eggs have been previously
laid.
The gall-flies deposit their eggs directly in the substance
of the leaf.
99. Another group of insects, much resembling the gallflies, deposit their eggs directly in the bodies of the larvse
and pupa of other insects.  They are called ichAneunonflies. These insects have on the hinder part of the body a




108              FIRST BOOK OF ZO6LOGY.
sharp, piercing sting, and with this organ the necessary hole
is made through which the egg is deposited.
A caterpillar soon hatches from  the egg thus deposited
by the ichneumon-fly, and feeds upon the fatty portions of
the body of the larva in which it has been so placed. But
this larva containing the ichneumon-caterpillar, meanwhile,
completes its growth and changes into a chrysalis, when the
inclosed ichneumon-larva devours the entire contents of the
chrysalis, and then changing into the pupa state soon emerges
as an ichneumon-fly, to go in quest of caterpillars, in which
to deposit its eggs. Thus it will often happen that a number of cocoons have been collected, from  which ought to
appear a certain kind of a butterfly, for examnple, but from
many of them a brown ichneumon-fly will emerge, a sight
quite as startling, to one not familiar with insects, as if a
robin should be seen to hatch from a hen's-egg.
If the pupils will collect from the fences a large number
of the chrysalides of the common yellow cabbage-butterfly,
and keep them in a box, with a piece of glass for a cover,
they will observe that while a butterfly comes from many,
from others, which have already changed to a lighter color,
little black flies will appear, crawling out of a hole in the
side of the chrysalis which had been made by some of the
imprisoned ichneumons. (See Fig. 104.)
100. Nearly every species of insect is infested with one
or more species of ichneumons, which deposit their eggs
either within the pupa, larve, or the eggs themselves.
There are some species of ichneumons which deposit their




SPIDERS.                       109
eggs within the eggs of the canker-worm moth, and, as tiny
as these eggs are, they are still large enough to furnish nourishment and room  for the complete development of the
insect feeding within.
Illn Fig. 74 an ichneumon-fly is shown on the wing, in
search of caterpillars wherein to deposit her eggs.
Fig. 67 also represents an ichneumnonfly of large size.
Fig. 104 represents ichneumnon-flies escaping from  the
chrysalis of the cabbage-worm moth.
FIG. 104. —CIYSALIS OF THE CABBAGE-WORM, FPROM WrIITCII ARE SEEN ESCAPING ICIINEUMON-FLIES.
CHAPTER XV.
SPIDERS.
101. Fort this lesson the pupils are to collect a number
of spiders, seeuring, if possible, the largest specimens.  A
wide-mouthed bottle, with a little alcohol, will answer to
collect them in. Let each pupil select the largest specimen
to study, and pin it to a piece of cork, or to a soft pine strip.
The legs are to be arranged with two pairs pointing forward
and two pairs pointing backward, as shown in Fig. 105.
Let them  study the following characters with the specimlen before them:
The spider is divided into two regions. That region or
part to which the legs are attached is called the cephalo



110                  FIRST BOOK  OF ZOOLOGY.
thorax.  The hinder region is called the abdome en.  Instead
of having  a separate head, as in true insects, the spider has
its head and thorax combined, and hence this part is called
the cephalo-thorax, a compound word meaning head-thorax.
A                    B  s
FIG. 105. —COMMON' GARDEN SPIDER.-A, as seen from above; B, as seen from below; p,
Palpi; qn, Mandibles; s, Spinnerets from which the Spider's Thread issues.
102. The spider has four pairs of legs, instead of three
pairs of legs as in the true insects.  Projecting in front are
a  pair  of jointed  feelers  called  al2pi (see  Fig. 105, p).
These look very much like legs, and in very young  spiders
can scarcely be distinguished from  them.
C      A
1  2   p m               8s    4
eIG. 1i06.-SIE-VIEW OF COMxMON GARDEN SPIDER. —C, Cephalo-thorax; A, Abdomen; 1, 2,
3, 4, First, Second, Third, and Fourth Pairs of Legs; s, Spinnerets; sz, Mandibles; i), Palpi.




SPIDERS.                          111
The mouth is armed with a pair of jaws which are attached  above the mouth and hang down in front, at the
end of which are the poison-fangs.   With these they are
enabled to secure and kill the flies and other insects upon
which they feed. The following figure represents the jaws
or mandibles.
0='"S
p   1                        1.p
FIG. 107.-FRONT PORTION OF COMMON GARDEN SPIDER GREATLY ENLARGED, showing, pp,
Palpi; m, Mandibles;  II, a Portion of the First Pair of Legs, and above, the Front of the
Cephalo-thorax shows, with the Eight Eyes upon it.
Directly behind the mandibles, are two smaller jaws,
called maxillae (see Fig. 108), which aid in crushing the food
and arranging it for the mouth.
PIG. 108.-INNER JAWS, OR MAXILLE, OF A CarxON GARDEN SPIDER —The first Joints of
the Palpi are seen also.
The spider has eight eyes, situated on the front part of
the cephalo-thorax.  They look like little black beads, and in




112               FIRST BOOK OF ZO6LOGY.
large spiders can be easily seen without the aid of a magnifying-glass.
103. The acbicomen has little appendages at its hinder end
called spinnerets, and from  these the spider produces the
thread with which it builds its nests and nets, the nets being
commonly called spiders' webs.
Highly magnified the spinnerets appear as blunt protuberances arranged together in pairs, and capable of being
contracted  or expanded.  These  spinnerets  are  covered
with hundreds of jointed hairs which are perforated and
through which the web-forming material escapes.  This material is fluid and something like the white of an egg.
Escaping from  the body, through hundreds of these nminute
openings, the strands of this fluid dry almost instantly, and,
uniting, form the delicate, yet comparatively strong, thread of
the spider. Thus it will be seen that the thread of the
spider is composed of hundreds of strands, which may be
often separated just as the fibres of a rope may be pulled
apart. Under the microscope the posterior end of the abdomen with the spinnerets looks like this.
FIG. 109.SPNEET OF A PR., one of the Tubular  Hrs from the Spinnerets, higly
F. 109.-SPNNeEX Ts OF A SPIDE.-mag one of the Tubular d. irs from the Spinnerets, highly
magnified.




SPIDERS.                      113
104. As the thread issues from the spinnerets, the spider
guides it with its hind pair of feet, and these are curiously
adapted for the purpose not only of holding and guiding the
thread, but also of enabling the spider to run rapidly across
its nets without getting entangled, while other animals become helplessly ensnared in attempting the same thing.
The ends of the legs terminate in three claws, a pair of
larger ones generally notched like a comlb, and a third one
like a spine which acts as a thumb.  Other notched spines
or hairs also aid in securing a hold upon the web, and even
if these fail to secure a footing, the leg itself is covered with
long stiff bristles pointing downward which are sure to catch
in the web. The two large notched claws, as well as the
other claw and spines, are highly polished, and consequently
present no roughened surface  to which the thread will
adhere.
The following figure (Fig. 110) represents the end of a
spider's leg magnified, showing the arrangement of hooks
and claws.
tm  o
FIG. 110. —END OF A COMMON GARDEN SPIDER'S LEO MAGNIFIED. —O, Outer Claws; in,
Middle Claw; t, Toothed Hairs.
105. By observing the spiders which build their nets
across the openings of windows and in other convenient




114              FIRST BOOK OF ZOOLOGY.
places, and while at work, they may be seen to use their
bind-feet in apparently drawing out the thread as it were
from  the spinnerets.  It will be observed that the thread
issues in a broad band, and, when these spiders are sluggish,
their thread may be caught on the end of a pencil by gently
rubbing the spinnerets with it, and then by withdrawing the
pencil the thread may be reeled off.
The various kinds of nets are adapted to entrap the
spider's food, which consists of flies and other insects.
Certain kinds of spiders do not build nets, but go in
search of their prey by stealthily creeping up and pouncing
upon it unawares.
It is a very interesting sight to watch the little black-andwhite spider (so common on the sides of houses) slyly approach
a fly which has alighted near it.  If the spider is on the side
of a window-sill and a fly has alighted near it, the spider
instantly turns round, facing the fly, cautiously and very
slowly mloves backward, till it gets on the upper side of the
window-sill and out of sight, when it rapidly approaches, now
and then peering over the edge of the sill, to see where the
fly is, and, finally getting directly above the fly, it gathers its
legs for a jump, securing its thread to the window-sill at the
same time, and then with a sudden spring seizes the fly in its
jaws. Sometimes the insect is much larger than the spider,
and flies away, with the spider tightly clinging to it; the
thread, however, holds fast, though sometimes run out to the
length of a foot or more. Soon the poison of the spider takes
effect, and the fly gradually weakens, and ceases its strug



SPIDERS.                      115
gles, when the spider carries it off to some nook, there to devour it.
106. One of the most common spider-nets is like the one
shown in Fig. 73. If the place selected is in the opening
of a window or similar place, the spider first runs a few
threads as a sort of framework, to which are to be afterward
attached the radiating threads, that is, those which run from
the centre of the net to the sides. Having arranged these
so near together that the spider can easily reach from  one
radiating thread to the other, the creature commences at the
centre of the net, and runs a thread from one radiating thread
to the other in a rapidly-unwinding spiral till it reaches the
outer edge of the net.  This is to form a staging, and also
the better to hold the radiating threads in place.  It then
commences at the outside, and going back over its last course
carefully constructs the permanent mesh; and, as it comes to
each radiating thread, it will be seen to attach to it the
thread it is now making, by simply pressing the spinnerets
against it.  As it goes around again and again, continually
shortening the circle, it gathers Lp the thread which was
first laid as a staging, and, rolling it up in little balls, drops
it to the ground.  This habit has led to the impression
that the spider eats its web.  The circular threads are
glutinous, while the radiating threads are smooth, and this
can be proved by throwing dust through the net, when the
cross-threads will catch and hold the dust, while the radiating threads will remain clean.  The actual centre of the net
is not the geometrical or true centre, but a little above it.




116             FIRST BOOK OF ZOOLOGY.
It may be observed, too, that the net does not stand vertical,
but leans a little, and the spider having completed the net
takes a position in the actual centre of the net, head downward and on the inclining side of the net. With its legs
outstretchedl, and resting on the radiating lines, it can feel the
slightest jar or agitation made by a struggling insect. The
spider being above the true centre of the net and on the inclining side, if the fly has become entangled below the centre,
it can instantly drop to the desired point suspended by the
ever-ready thread which it makes, and, swinging to the net,
it almost instantly catches the fly.
The pupils would do well to watch the spiders while they
are constructing their nets, and to observe and describe, or
sketch in outline, the different kinds of nets they find and
the kinds of spiders which construct them.
107. B1esides the nets made by spiders to ensnare insects,
some species have the power of running out a long thread
which answers the purpose of a balloon in raising them from
the ground and carrying them floating a long distance in the
air.. In constructing this buoyant means of transportation,
the spider does it at peculiar times of the day, and in peculiar
positions. Selecting some place where the heated air is rising
from the ground or from the side of a fence, it turns up
its abdomen and allows the rising current of air to carry
upward the thread which is being made, and, when this thread
is of sufficient length for its buoyancy to overcome the weight
of the spider, it floats away with the spider hanging below.
The following represents the young spider in the atti



SPIDERS.                        117
tude of throwing out its thread for the purpose of sailing
in the air.
Voyagers often meet with these spiders in myriads as
the wind sweeps them from the land.
FIG. I11.-YOUNG SPIDE GREEATLY ENLARGED, SHOWING ITS ATTITUDE IN THROWING OUT TRE
ThrPEADD, PREVIOUS TO RISING FROM THE GROUND. (Copied from a Figure by J. H. Emerton. )
108. The spider also constructs cases to hold her eggs, and
lines them  warmly with the finest web.  These nests vary
greatly in appearance.  A  very common variety, somewhat
oval in shape, may be found suspended in barns and sheds.
The pupils should collect and open these cases or nests, and
they will be found to contain little eggs, sometimes rolling
out like beads into the hand, or, the eggs having hatched,
hundreds of little spiders will appear moving within the nest.
Nests, or, more properly speaking, egg-cases of different
kinds, may be collected under stones and logs, and wherever
spiders' nests occur. The little spiders hatching from the egg




118                   FIRST  BOOK  OF ZOOLOGY.
will grow to twice their size in the nest, without apparent
food, and it becomes evident that, in some cases, they
must eat each  other, as Prof. Wilder has observed  within
some of the egg-cases a far less number of spiders than there
were eggs in the nest at the  outset.   These nests may be
kept in boxes, and the eggs will hatch in due time.
A             B             C
FIG. 112.-SPIDEnRs' NESTS OF DIFFERENT KINDS CONTAINING EGGS.-A and C are common
nests in sheds and barns; B was found under a board in the field, the part containing the
eggs stands upon a stalk.
109. The young spider comes from the egg resembling in
form  the parent spider, except that the legs are much shorter
in  proportion  to  his relative  size, and  the palpi appear so
large that they look like another pair of legs, as they then
are in fact, but they afterward become modified to feelers.
y
4/
FIG. 113.-ENLARGED FIGUREl OF A YOUING SPIDER JUST FROMI TIIE EGG, WITH THE FIRST
MOULT, m, adhering to the Hinder Part of the Body;?J, the Natural Size of the Spider; i,
extremity of a Leg highly magnified, showing an Outer Skin which has not been shed.




As the young spider grows, it sheds its skin at short intervals of time.  If the pupils will examine the young spider
soon after it is hatched from  the egg, they will find attached
to the hinder part of the body the skin which has just been
shed.  This curious process of shedding the skin, or moulting,
occurs at intervals, till the spider has reached adult size.
FIG. 114. —THE CAST-OFF SKIN OF AN ADULT SPIDEnR.
110. The cast-off skins of spiders are very common in
their webs, and, if the pupils examine any barn-window
which is covered with spider's webs, they will be sure to find
some of these cast-off skins, like the one represented in Fig.
114.
The mother-spider, generally so timid, overcomes her fear
during the time she has the care of her eggs, and with
many spiders the egg-cases are directly cared for by the
mother, she oftentimes carrying them about with her or holding on to them and showing the greatest solicitude for their
safety.  Let the pupils try to separate the egg-case from the
mother-spider, and they will then learn how courageous the
spider is at this time, and how persistently she remains by
her eggs.  Some species of spiders carry their young on
their backs, and move about with them.




120             FIRST BOOK OF ZOOLOGY.
A small black spider was picked up in the woods, which
had her body entirely covered with young spiders, which
were evidently newly hatched.  When the mother-spider
was picked up, all the little spiders becoming fiightened
jumped off, but just before jumping each one attached a tiny
thread to its mother's back, and as the spider was held up in
the air there hung below, suspended by invisible threads,
the whole progeny looking like little black beads.  The
mother-spider was then thrown down among the dead leaves,
sticks, and pine-cones. She did not run away, however, but
waited tillll all of the young ones had found their way through
this tangled wilderness, safely back to their mother, and this
they accomplished by means of their threads, one end of which
they had previously attached to her back. Having waited
till all had been gathered in this way, she continued her
journey.
111. The spider has no power of throwing or ejecting
its thread to distant objects, as many suppose. When threads
are seen stretching from one tree to another, the spider has
caused the thread to issue from the spinnerets, and the wind
has then caught it and borne it along, till finally it gets
entangled with some object, and in this way the spider is
enabled to cross from one point to another.
These creatures are not so dangerous as many suppose, and
but very few authenticated cases are known of man having
been bitten by these animals; though the larger spiders
at the South, and in California, as the tarantula, for exam
ple, can inflict a dangerous wound.




DADDY-LONG-LEGS, CENTIPEDES, AND MILLIPEDES.  121
CHAPTER XVI.
DADDY-LONG-LEGS9 CENTIPEDES AND MILLIPEDES.
112. Is the insects proper, or true insects, the pupil has
learned that the head, thorax, and abdomen, are separated
into three regions or parts. In the spiders, it has been seen
that the head and thorax are combined, forming a single
region or part, and called the cephalo-thorax, while the abdomen appears as a distinct part. There is another group
of animals allied to the spiders, the individuals thereof having four pairs of legs, and the head, thorax, and abdomen,
more or less merged together. The animals belonging to
this group are called in various parts of the country, daddylong-legs, grcnddacddy-long-le/s, grandfatlzer-gracybeatrds, and
harvlest-men, and in northern New York are known by the
name of "' grab for gray bears."
Certain species are common around houses and sheds,
others are found in the woods. They are easily recognized
by their small bodies and extremely long and slender legs.
It is difficult to hold them in the fingers, as some of the legs
are liable to drop off on the slightest effort made to retain
them.
In the middle and on the back of the cephalo-thorax, there
is a slight eminence, upon which are situated the eyes, two in
number. The abdomen appears distinctly segmented.
113. Their food consists of small insects, such as flies and
6




122 /,V-I             FIRST  BOOK  OF ZOOLOGY.
mosquitoes;  and these they go in quest of, slyly approaching
and pouncing on their victim  and seizing it with their mandibles, which are furnished at their ends with a pair of nippers,
which enable them  to retain their prey.  (See Fig. 115, in.)
They build no net to entrap their prey, and are weak and
helpless compared with their higher relatives, the true spiders.
They are dependent then for food  upon  such insects as they
can overcome, and these they devour, differing in this respect
from  the rapacious spiders which  suck the fluid contents of
their prey, rejecting  the rest.   Certain species are known to
FoG. 115.-YorUNG DADDY-LONG-LeGs, ENLAGED: y, showing Natural' Size; B, Under Side
of Body still more enlarged; nm, Mandible of Left Side; p, Palpus of Right Side; P,
Palpusj greatly enlarged; P 0, End of Palpus, showing Notched Claw; L, End of Leg,
showing Claw; E, Eye-Prominence, with the Two Eyes. (The three last-mentioned Figures are greatly magnified.)




DADDY-LONG-LEGS, CENTIPEDES, AND MILLIPEDES.  123
be cannibals, as some have been seen to pounce upon a brother
daddy-long-legs and devour it, leaving only the legs.
It is believed that in the Northern States they do not survive the winter, as in the spring only young ones are seen,
and these attain full size by autumn. At this season, the eggs
are laid under stones and in the cracks of boards and other
protected places, where they remain to hatch out in the following spring.
114. Under old boards in gardens and hidden beneath
stones and dead leaves in the fields and woods, the pupils
will find the creatures to be studied in this lesson.  They
are commonly known as centipedes, and in the Eastern States,
at least, are also known as earwigs; though the earwig
in England is an entirely different animal, being a true sixlegged insect.
The centipede belongs to a group of animals called J/yriopocds and the animals belonging to this group are composed
of a great many similar segments, some species having as
few as ten segments, others having over two hundred segments. In this latter respect, these creatures resemble the
worms, but differ from the worms in having jointed legs and
antenna, and in these last-named characters resemble the
insects, besides having other affinities with the insects, in
breathing air through  spiracles and trachese which run
through the body.
There are two very distinct groups of /lyriopods; one
group comprising the true centipedes, in which the body is
flattened, the segments loosely joined, and the legs gener



124               FIRST BOOK OF ZOOLOGY.
ally equaling, and sometimes exceeding, the width of the
body.
The segments in many cases are unequal in length, some
of them  being very short and alternating with long ones,
though all bear a pair of legs below. The antennae are much
longer than the legs, and are often composed of a great many
joints. A pair of modified legs reach out behind and look
like a hinder pair of antennae.
In a few forms the eyes are compound as in the insects,
while in others the eyes are separate as in the spider, and
are called ocelli.  These are grouped on each side of the head,
at the base of the antennae.
A magnified view of the head, showing group of
[FIG. 116.-COMMON CENTIPEDE,   eyes at the base of antennae. A few joints only of
NATURAL SIZE.     the antennme are shown.
115. The jaws or mandibles are large and jointed, with
the terminal joint long and sharp as in the spiders. The
other pairs of jointed appendages act also as mouth-parts.
The under lip is notched with fine teeth, as shown in the following figure, which represents the under surface of the head
of the species of centipede shown in Fig. 116.




DADDY-LONG-LEGS, CENTIPEDES, AND MILLIPEDES.  125
These creatures are active in their motions, and rapacious
in their habits. Some of them feed on small insects, others
attack earthworms.  Their bite is venomous to insects, and
one species having very long legs will produce by its bite a
severe pain lasting several hours. A large species found in
the Southern States, and in the tropics, and commonly known
a       mPz
FIG. 117.-SHOWaING MAGNIFIED VIEW OF THE UNDER SURFACE OF THE HEAD OF A CENTIPEDE: ae, Antenna; m p, Maxillary Palpus; fj, Foot-jaw;;f, Poison-Fang of Foot-jaw;
1, Labium; m, Maxilla. The Mandibles are hidden behind the other parts, and do not
show.
as the centipede, is considered a dangerous animal from its
bite. The feet of this species are supposed to poison by their
touch, since, when they run over the flesh, small ulcers appear
where the feet have come in contact with the skin.  The
pupils may collect these animals, and either dry them and
stick them to cards, or preserve the specimens in vials filled
with alcohol.
116. The other group of myriopods, commonly known as




126                FIRST BOOK OF ZOOLOGY.
millepeds, have a long, cylindrical, and oftentimes shiny body,
composed of a great many segments so smoothly joined together that it is difficult to see the separation between them.
The antennae are short, there are no long caudal appendages, and the legs are short and feeble. At first sight it
would appear that these creatures were exceptional among
insects and spiders, in having two pairs of legs to one segment; but it has been learned, by studying the very young
milleped, that there is'really but one pair of legs to a segment, but thiat the segments grow together in pairs, so that
each apparent segment is composed of two segments.
avn.tevcsec. jK II
A             B
FIG. 118.-A COMMON MITILIPED. The line underneath the figure represents the length of
the specimen from which the drawing was made. A, a Magnified View of the Head of the
Milliped represented above; B, a Magnified View of the Left Jaw.
These creatures live on decaying matter, and are slow and
weak in all their movements.  When touched, or alarmed,
they coil up in a closely-wound roll. The body is hard, and
the animal can be stuck on a card for the cabinet. The eggs,
to the number of sixty or more, are laid in little burrows




DADDY-LONG-LEGS, CENTIPEDES, AND MILLIPEDES.  127
previously prepared by the creature in earth that is neither
too moist nor yet too dry.  In preparing the burrow  the
female makes use of the fluid which comes from her mouth,
and which enables her to stick the earth together in little
balls, and these she passes up from her burrow by means of
the little legs which grasp the pellet and convey it from  one
pair of legs to the next pair, and so on till it is thrown
out of the burrow. After the burrow is completed, and the
eggs laid, the entrance to the nest is carefully filled up with
clay, or dirt, moistened with fluid from the mouth.
117. It has been learned, in studying the development of
the insect proper, that the worm-like larva comes from  the
egg with its full number of rings or segments, and that, as
the creature matures, some of these segments are so merged
into other parts, particularly so with some of the caudal ones,
that it seemed as if the perfect insect has a less number of
rings than the larva.  In the myriopods, however, the young
creature as it hatches from the egg possesses only a few segFIG. 119.-HIGHLY-.MNIAGNIFTED FIGURE OF A fVERY TOUNG MILLIPED, SHORTLY AFTER HATCHING FROM THE EGG.
(Reduced from a figure by Elias Metschnikoff.)
ments, but as it grows new segments are from time to time
formed near the hinder part of the body, until the creature




128             FIRST BOOK OF ZOOLOGY.
attains adult size, when it may possess over a hundred segments.
Like true insects, however, the young myriopod mnakes
its appearance from the egg with three pairs of legs. The
body, however, is never divided into a thoracic portion, and
an abdominal portion, as in the true insects, or into two regions as in the spiders, but after the head there succeeds a
continuous row of similar segments to the tail.
118. In studying the insects, spiders, and centipedes, or
myriopods, the pupils have learned something about three
groups of animals which have in common a body composed
of segments, and possessing jointed legs.  They all breathe
air through holes in the side of the body, called spiracles,
the air, thus breathed, finding its way through various parts
of the body by means of little tubes called tracheae, except in
the spiders, where little sacs, called pulmonary sacs, take the
place of tracheae.
In the true insects the segments of the body are gathered
into three regions, called respectively the head, thorax, and
abdomen. In the spiders the segments of the body are gathered into two regions, called respectively the cephalo-thorax,
and abdomen, the head being merged in the thorax. In the
myriopods the head is again distinct as in the true insects,
but the remaining segments of the body are distinct and are
not grouped into regions.
The true insects have three pairs of legs. The spiders
have four pairs of legs, while the myriopods have no definite
number of legs. In some species there are nearly two hundred




DADDY-LONG-LEGS, CENTIPEDES, AND MILLIPEDES.   129
pairs of legs, and in no species are there less than ten pairs of
legs. The true insects alone have wings.
119. In the growth or development of the true insects
and spiders, the young animal comes from  the egg with its
full number of segments complete, while in the inyriopods
the young animal comes from  the egg with a few  segments,
and new ones are added as the animal grows.
Some of the characters of the insects, spiders, and myriopods, may be represented as follows:
1        2    3
Three pairs of legs, and having wings.
TRiE INSECT.-Body divided into Three Regions.
1  2        3   4
Four pairs of legs.
SPIDER.-Body divided into Two Regions, Head not separate.
No definite number of legs
MYRIOPOD.-Body not divided into Regions, but Head separate.
rIG. 120.-ANIMALS WHOSE BODIES ARE COMPOSED OF SEGMENTS POSSESSING JOINTED LEGS,
AND BREATHING AIR THROUGI OPENINGS IN THE SIDES OF THE BODY.
On account of some of these characteristics above mentioned, with others not mentioned, being held in common by
the true insects, spiders, and myriopods, these creatures form
a natural group in the animal kingdom, just as the snails,




130              FIRST BOOK OF ZOOLOGY.
mussels, oysters, and clams, possessing certain characters in
common, together form a natural group of animals.
There are, however, many other animals which are neither
insects, spiders, nor myriopods, and still possess a body composed of segments, and also have jointed legs, and these animals are to furnish the subject for the next lesson.
CHAPTER XVII.
C RAWFIS H A N D LOBSTE R.
120. THE fresh-water Crawfish, or fresh-water Lobster as
it is sometimes called, is very common in many of the Western rivers.  It may be collected in little pools by the riverside, and kept alive for a long while in a jar of water. It
may be fed on the larva of insects and fresh-water snails.
It would be well to keep the animal alive for a while, so
that its motions in swimming and crawling may be observed. For the cabinet, it can be dried with the legs outstretched, or specimens may be preserved in alcohol.
The general form of the body is much like that of the
salt-water lobster, differing, however, greatly in size; the
crawfish varying from three to five inches in length, and
the lobster attaining a much larger size.
The animal is divided into two regions, the body proper,
to Tahich the legs and big claws are attached, and the abdomen, consisting of the jointed portion behind.  The head




CRAWFISH AND LOBSTER.                   131
does not appear separated from  the body as in the insects,
but is combined with the thorax, and hence this part is called
the cephalo-thorax, as in the spiders.  The cephalo-thorax is
covered by a continuous shield, or shell, called the caroacace,
while the abdomen is divided into a series of segments. This
part can be bent snugly beneath the body (see Fig. 121).
FIG. 121.-FRESH-WATER CRAWFISH FROM THE MISSISSIPPI. RIVER.
At the hinder end of the abdomen are five flattened appendages, which serve as fins, by means of which the animal
can swim vigorously backward.  (See Fig. 122.)
FI, 122.-TAIL OF CRAWFISH SHOWING FLATTENED APPENDA GES FOR SWIMMING.
There are two compound eyes in front, which rest upon
little jointed stalks, so that the creature can turn theim in
various directions.




132              FIRST BOOK OF ZOOLOGY.
121. Just below the eyes are two long, and two short and
double antenne, or feelers, and directly below these are six
pairs of variously shaped and jointed appendages closely
packed together.  They surround the mouth and assist in
secmuing and preparing the food for the stomach. The first
pair are called jaws, or imandibles, and are furnished with
sharp cutting edges for biting the food, and a flattened surface for grinding or crushing it. The next two pairs are
called  azxillce, and are accessory jaws.  The pair of mandibles and the two pairs of maxillae, with another pair just
behind, making four pairs in all, belong to the head, the
other two pairs of mouth-parts belong to the thorax, and are
so evidently modified claws or feet that they, with the pair
just in front of them, are called foot-jaws or mnaxillipedes.
(See Fig. 126, in which these parts are all named.)
122. From the under side of the body project five pairs
of jointed legs, and these differ in shape and size. The first
pair are much larger than the rest, and in the lobster are
FIG. 128.-A BIG CLAW OF THE LOBSTER, SHOWING THE WOODEN WEDGE, a,
called the big claws.  They carry at their extremities big
pincer-like jaws capable of giving a sharp nip, and are probably used as weapons of defense, and also to hold on to their
prey.  The lobster can bite very severely with these big




CRAWFISH AND LOBSTER.                133
claws, and for this reason the fisherman drives in a little
wedge of wood to prevent the animal from opening the movable part, so that he can handle it without being bitten.
The other legs are long and slender.  The two forward
pairs ending in slender nipp&es, while the two hinder pairs
end in a single projecting claw. With these four smaller
pairs of legs the crawfish and lobster crawl or walk.
On the under side of the abdomen are little flattened appendages arranged in pairs, a pair to each ring or segment.
The animal not only swims backward by means of the broad
FIG. 124.-ONE OF THE FLATTENED OR ABDOMINAL APPENDAGES OF A LOBSTER.
fins on the end of the tail, or abdomen, but has the power
besides to swim in a forward direction by extending the abdomen, and using the little fins below as swimming organs.
123. The crawfish, like the lobster, breathes in the water
by means of gills. These are attached to the base of the
legs and are concealed on the sides of the thorax by the
carapace, which covers them.  By forcibly tearing up the
side of the carapace, there will be exposed the gills which




134                  FIRST BOOK  OF ZOOLOGY.
look like plumes.  This space may be called the gill-chamber,
and the water flows into it by passing under the edge of the
carapace back of the big claws, and passes out of an opening
near the mouth-parts. The currents of water flowing in to
the gill-chamber are induced by a stiff appendage attached to
the base of the second pair of maxillhe called the flabelivm
(see Fig. 125), and which swings back  and forth  and scoops
the water into this chamber.  These gills are shown as they
appear in  the  crawfish.   In  tearing  off the  claws of the
lobster, the gills are often drawn out too, and remain attached
to the base of the legs.  (In the lobster the carapace can be
easily bent up, so as to show the gills.)
In the following figure a crawfish is shown with a portion
cephalo-thorae           abdomen
snall anttenna                             W\'   N    V
large anteazn                )            D2iii 
mandible
maxillipedes    2- - -- --------— A
C /   B                 A.TIG. 125.-CRAWFISH SEEN FROMJ THE SIDE, WITH THAT PORTION OF THE CARAPACE REMOVED
WVHICH COVERS THE BRANCHIUE OR GILLS. THE, APPENDAGES OF THE LEFT SIDE ONLY
HIIOWN.-, lRegion of Stomach; A, Abdominal Appendages; B, Bases of the Four Small
Legs; C, Base of Large Claw;.f; Flabellum attached to the Second Maxilliped; e, Eye.




CRAWFISH AND LOBSTER.              135
of the carapace on the left side removed to show the gills as
they appear in the gill-space. The big claw and the four
smaller claws or legs are cut off, so that the other parts can
be plainly shown.
124. If the pupils are skillful enough, it will be a good
exercise for them to separate the various appendages of the
crawfish, and arrange them upon a card, just as the beetle
was arranged, as shown on page 66, fastening the carapace
in the middle of the card with the back uppermost, then
gluing the abdomen to the card, or, if possible, separating
each ring of the abdomen and gluing each one separately to
the card, one behind the other, and then arranging the appendages on each side of the thorax and abdomen, and with
a pen marking the names of the various parts on the card.
Figure 126 represents the way in which the mouth-parts
of a crawfish or lobster may be arranged.
As the lobster is a much larger animal than the crawfish, it will be easier to separate its appendages, and these
may as well be taken from a specimen which has already
been boiled, or as it may be obtained in the market. They
may then be dried and fastened to a card with glue. The
red color of the lobster appears only when the animal is
boiled. When alive the color of the creature is a reddishyellow mottled with bluish or greenish-black.
125. The eggs are carried by the crawfish and lobster
glued in masses to the swimming appendages which are
attached to the lower surface of the abdomen, and the
creatures retain them ill this way till the young hatch out.




136                 FIRST BOOK OF ZOOLOGY.
This feature is characteristic of the class to which these animals belong.  How  different in this respect from  the creatures already studied, in which the eggs are deposited and
left by the animal!  It has been learned that certain spiders
too carry their eggs round with them, and protect them.
BTTING-JAW...............   dible.
( First ailla..............
LITTLE JAWS OR ACCES- t
SORY JAWS, OR MAXILL.lSecond Naxillace..........
Fr st fllaxilliped-... -----—.
FOOT-JAWS, OR MAXIL-  Second Jalcexilliped,... —-.
LIPEDES.  
Third Jlaxiliped.....
FIG. 126.-MOIITR-PAR'TS OF A CRAWFISH FROM THE LEFT SIDE.
Fig. 128 represents a crab carrying its eggs glued to the
appendages on the under surface of the abdomen.  Pupils
having access to lobsters in the markets, will, by looking over
them, find some specimens in which the eggs are being carried
in this way.
126. The young animal in growing sheds its entire shell,




CRAWFISH AND LOBSTER.                 137
in this respect again resembling the spider.  This process is
called molntinqg, a term  used in describing a similar process
in the spider.  The lobster and crawfish continue to shed
their shells at different periods, till they attain full growth.
It is stated that the crawfish sheds its shell annually. If the
pupils will keep some of these creatures alive, they will probably have an opportunity to observe this curious process of
moulting, in which the entire outer skin, or shell, is discarded,
so that there is left, complete in all its parts, the empty crust,
like a discarded garment.  The carapace separates from  the
abdomen above and cracks along the back, and by a series of
efforts the animal pulls its way out.  Great trouble is experienced in withdrawing the legs, and oftentimes a leg is left
behind, and cases are recorded wherein the animal has perished
in the struggles to liberate itself from the old skin.  For
some time the animal shows great timidity, and the lobster,
when it has freshly shed its skin, retires to some secluded
place, and there remains till the soft and tender skin has
become thickened and hardened, so as to  enable it to
withstand the attack of its enemies.  Lobsters often lose
their legs in fighting, and on a sudden alarm are capable of
dropping them off.  The loss of the leg in this way is made
good by the curious property the stump has of reproducing
another leg, which grows out' again, jointed and shaped like
the one lost, 6nly much smaller than the original one.  At
each succeeding moult, however, the leg becomes larger and
larger. If the pupils will now carefully examine a lot of
lobsters, they will notice among them  some specimens in




138               FIRST BOOK OF ZOOLOGY.
which some one of the legs will be much smaller than its
mate on the other side.  This shows where a new leg has
been growing, to replace one previously lost.
127. The young passes through a remarkable series of
moults, or shedding of the shell, and each moult brings it
nearer in appearance to the general form of a lobster. The
following figure presents the appearance of a young lobster
which has undergone several such moults.
FIGo. 127.-A YOUNG LOBSTER MAGNIFIED. —C shows the Natural Size of the Creature.
(Reduced from a Figure drawn by Sidney I. Smith.)
CHAPTER XVIII.
CRABS, HERMIT-CRABS, AND OTHER CRUSTACEANS.
128. THE class of animals to which the crawfish and
lobster belong is called Crustacea, a name derived from a
Latin word, crusta, meaning a crust, or the shell with which
the animals of this class are covered.
To this class belong the crabs, hermit-crabs, shrimps,
and an infinite variety of forms found in salt-water, certain
little creatures found in the great lakes and other fresh




CRABS, HERMIT-CRABS, AND OTHER CRUSTACEANS.  139
waters, as well as a little creature known as the sowbug, which
is common -under stones and boards in damp places. By far
the larger proportion of these animals are found in salt-water.
Pupils having access to the sea-coast will find along the
shore, and in pools of water left at low tide, a number of
species unlike any thing found in fresh water.
The common crab may be studied and compared with
the lobster.  It will be found that the crab has the large
claws, little legs, mouth-parts, antenns,  and other details
similar to the lobster and crawfish.  The body, however,
is entirely unlike in shape; instead of being long and cylindrical, it is wide and flattened, and the long, jointed abdomen
so characteristic of the lobster and crawfish is quite concealed
in the crab. At first sight, the creature would appear to
have no portion corresponding to this part in the lobster,
but beneath the body there will be found a close-fitting piece
composed of segments or joints, and, if this be raised or
opened, the relation between this small piece and the large
jointed abdomen of the lobster becomes at once apparent.
The crab carries her eggs attached in masses to the abdominal appendages which are arranged in pairs on the
segments of the abdomen, as in the lobster.
In the following figure, which represents a crab carrying
her eggs, a comparison of parts may be made between it and
the crawfish or lobster.
The eggs as they are laid are covered with a sticky fluid,
which thickens into threads and holds the eggs together and
also holds them  in masses to the abdominal appendages.




140                   FIRST  BOOK  OF ZOOLOGY.
These appendages, having long hairs, retain the eggs all the
more securely.
B   1
FIG 1 -VIEW OF  N      TH T   ABD       XTEND  AN        NG A
FIG. 128.-SIDE-VIEW  OF COMMON CRAB, WITH THE ABDOMEN EXTENDED AND CARRYING A
MASS OF EGGS BENEATH.-e, Eggs.
Under the microscope the eggs appear like bunches of
berries or currants.  The following figure represents a few
eggs from  a common crab:
A                      B
FIr. 129.-A, a few Eggs from a Common Crab, enlarged; B, Single Egg greatly enlarged,
showing more plainly the hardened Thread t, by which they are attached to each other.
This Egg shows the young crab just beginning to form.
129. The small legs of a crab terminate in a single claw.
There are no nipper or pincer-like ends as in the two forward




CRABS, HERMIT-CRABS, AND OTHER CRUSTACEANS.  141
pairs of claws of the lobster, and in studying the crustaceans
generally an infinite variety of modification will be found in
these parts. In the crab which is so much sought after for
food, and which is known as the soft-shell crab (a condition
which indicates that the crab has just moulted, or shed its
hard shell), the hinder pair of legs have the last or terminal
joints flattened, and these flattened joints are used as fins by
means of which the creature swims through the water.
FIG. 180.-RIGHT ]IIND-LEG OF THE EDIBLE CRAB.
The above figure shows the appearance of the right
hind-leg of one of these crabs. Compare this with the corn
mon crab shown in Fig. 128.
130. A curious little crab, called the oyster-crab, malkes its
home within the shell of the oyster, living in the gill-cavity
FIG. 131. —OYSTEI-CRAB. The Tail is hidden beneath the Body, one Segment only showing.
of the animal. Specimens may sometimes be found in
canned oysters, and, to those who do not have access to the
sea-shore, these creatures will furnish objects from which
an idea of the crabs or short-tailed  crustaceans may be




142               FIRST BOOK OF ZOOLOGY.
got.  The tail will be found flattened against the under
side of the body. Another species occurs in the salt-water
mussel.
In the female crab, a figure of which is given (128),
this part is very large and will be oftentimes found holding
a mass of eggs.  With care the creatures may be dried,
and their various parts separated and stuck upon cards for
the cabinet.
FIG. 132. —HERMIT-CRAB IN THE SHELL OF A SEA-SNIL.
131. The hermit-crab possesses the general features of the
common crab and lobster.  The abdominal portion is long
and cylindrical, and, instead of being encased in a hardened
shell as in the lobster, it is soft and pliant, with scarcely a
trace of hardened parts to indicate the segments.  The creature, having this defenseless part, protects itself by securing
the hard shell of some sea-snail as a house in which it constantly lives.  The cau-dal appendages are curiously modified




CRABS, HERMIT-CRABS, AND OTHER CRUSTACEANS.  143
to enable it to retain its hold on the shell, and the other abdominal appendages are rudimentary or wanting on the right
side, or that side which comes most against the inside of the
shell, as if they had been worn off. Wherever the creature
goes, it drags the shell after it as a house.
7    7
/f-'~.............................. a
FIG. 133.-HERMIT-CRAB REMOVED FROM ITS SHELL: A, Hardened Ridge which bears against
the Inner Edge of the Aperture of the Shell; a, a, Appendages to which the Eggs are
attached.
As the hermit-crab grows, it passes through the samne
features of moulting which characterize the crustaceans generally.  The shell which protects its soft defenseless abdomen
has, of course, no power of growth, and is abandoned when




144               FIRST BOOK OF ZOOLOGY.
the hermit-crab gets too big for it.  The creature has, therefore, to go in search of another house slightly bigger than
the one ready to be discarded.  It is said that it does not
always content itself with the dead shells that strew  the
beach, but has been seen attacking a live snail and eating it
for the purpose of occupying its vacant shell, and this is
rendered probable by the fact that they so often occupy
fresh and perfect shells.
Not unfrequently they are found living in old and beachworn shells which they have dragged about so long as to
have worn the shell nearly through at the place where it
rests and rubs against the sand.  The pupils may collect
hermit-crabs of all sizes on the shores.
The figure on the preceding page represents a hermitcrab after its removal from  the shell.   The creature is
drawn as it appears lying on its back.
132. There are comparatively few species of crustaceans
found in fresh water; and, with the exception of the species
of crawfish and a few others, the fresh-water crustaceans are
of small size.
FIG. 184.-FRsH-WATER CRUSTACEAN. The Line below represents the Natural Length of
the Animal.
(Reduced from a Figure, in S. I. Smith's Report, of Fresh-Water Crustacea, published by U.
S. Fish Commission.)




CRABS, HERMIT-CRABS, AND OTHER CRUSTACEANS.  145
The figure 134 represents a small species which is common in stagnant pools in nearly all the Northern States.
From  this species the pupils may study a form in which
the segments of the thorax are not covered by a continuous
shield.
The sowbug is a crustacean which lives out of water,
though always requiring damp surroundings.  It may be
collected under logs and stones.  In this creature the seven
segments of the thorax are easily counted.
FIG. 185.-CoMMoN SowaBG.-The line shows the length of the specimen from which this
figure was made.
The eggs of the sowbug, as well as those of other species
of crustaceans of the same group, are carried on the under
side of the thorax and between the legs, in a little br6oocling
cavity made by leaf-like parts which lap over each other
and hold the eggs in place.
The eggs of these crustaceans may be found by examining the under side of the body, and observing a lightishcolored space between the legs.  With a pin or the point
of a knife-blade they may be scraped away without injuring
the animal.  They are very minute, and only under the
7




146              FIRST BOOK OF ZOOLOGY.
microscope can the development of the young creature be
watched.  The following figure represents a single egg of
the sowbug highly magnified:
FIG. 136. —EG OF SowBUG, HIGHLY MAGNIFIED.-The little dot, at one side, represents the
natural size of the egg. The head faces the left.
Around the upper edge of the emzbryo (as a young animal
in the egg is called), from eighteen to twenty little blunt appendages may be seen; these represent the legs and other
appenldages of the body-c the one longer than the rest is an
antenna.  As the creature grows, these appendages become
jointed and variously modified to form the legs, mouth-parts,
antenn,e, and the appendages on the tail, which differ greatly
fronm each other, though at the outset they are all alike.
133. Having studied a few of the many different kinds
of crustaceans, let the pupils examine them together to find
some points characteristic of them all.
Their bodies, in conimon with the insects, are composed
of segments to which are attached jointed appendages of
various kinds.  This body is divided into two regions, the
cephalo-thorax and the abdomen. In some the cephalo-thorax
is covered by a continuous shield, called the carapace, as in
the crawfish, crab, lobster, and shrimp.  In others the segments of the cephalo-thorax are distinctly separate, and
movable upon each other, as in the sowbug and certain other




BIVALVE CRUSTACEANS AND BARNACLES.           147
crustaceans, one of which is figured on page 145.  The cephalo-thorax is composed of fourteen segments, seven of these
belonging to the head, judging from the number of appendages which arise from that part.  The abdomen is supposed
to possess seven segments, though the last one is so rudimentary that its existence as a true segment has been denied by
some.
The deep line running across the back of the carapace, in
the crawfish and lobster, is called the cervical suture, and
represents the dividing line between the head and the thorax.
The following outline represents a sowbug, with the
regions of the body marked.  Compare this with Fig. 125.
head. 
thorax. 
abdomena. 
FIG. 137.-SOW-BUG, WITH RE GIONS OF BODY MARnKED.
CHAPTER XIX.
BIVALVE CRUSTACEANS AND BARNACLES.
134. THE crustaceans during their growth shed their hard
outer covering at intervals, and, in this as in many other respects, resemble the spiders.  In the possession of gills, in



148             FIRST BOOK OF ZOOLOGY.
stead of air-cavities, the crustaceans show a marked difference
between themselves and spiders.
Now, there are hundreds of minute crustaceans in which
it would be hard to recognize any close relations between
them and the crustaceans already studclied.
Among these odd forms may be mentioned certain little
animals abundant in ditches and pools throughout the coluntry. Sonie of these creatures are smaller than a pin's-head;
others are as large as an ordinary white bean.
At first sight they might readily be mistaken for bivalve mollusks, as the body is covered with a bivalve shell,
which partly opens and shuts, and is firmly attached to
the body within. If the pupils are fortunate enough to
collect some of these creatures in a net and watch them as
they actively dart about in a jar of water, they will at once
see the difference between them and the clam or mussel.
Instead of the animal's projecting a soft and fleshy foot
with which to creep slowly along, as in the mussels, they will
see numbers of little jointed, swimming legs partly protruded,
and jointed antennae thrust out in front; and, if their eyes
are keen enough, may detect a little black speck just above
the Antennse, which represents the eye.
The following figures represent a species collected in
Dubuque, Iowa, and another form from Lynn, Massachusetts.
135. The concentric lines on the shell appear like lines
of growth, and such they really are; but they are not made
like the lines of growth on the mussel.  When the creature
moults, the delicate skin covering the antennTe and swim



BIVALVE CRUSTACEANS AND BARNACLES.                         149
ming  legs is discarded.    The  imoulting  process  also  takes
place with  the  bivalve  shell, but, instead  of its being  discarded, the rnmoult is held or cemented to the new shell which
forms underneath.   Mloult after imoult of the shell is thus
retained, the increasing  size of each  imoult showing as sepD                            L           S
B
FrI. 138.-FRESH-WATER CRUSTACEANS; D, Species from Dubauque, Iowa; e, Eye. The line
below indicates the natural length of the specimen; L, Species from Lynn, Mass.: this is
figured the natural size; S presents a highly-magnified section of one of the shells, to
show the successive moults, these being numbered in their order of moulting; B shows
the appearance of a portion of the edge of the shell along the back, representing the successive moults lapping one over the other.
arate  concentric lines of  growth.   If the shell is cut into
and the cut edge is examined with  a microscope, the successive moults will be seen resting one upon  the other, like the
leaves of a book.  By reading  carefully the description  accompanying Fig. 138, the pupils will learn maore about it.
The  very  young  stages of  these  creatures  have  some
resemblance  to the young of the barnacle shown in Fig. 141.
136. Another group of animals classed with the crustacea
is still more unlike  the forms already studied.   These are




150               FIRST BOOK OF ZOOLOGY.
the barnacles.  They are found in immense numbers covering the rocks and piers in places between high and low
water mark.  In nearly all places along the coast the rocks
are whitened by their numbers.  Pupils living inland can
get specimens of the barnacle by visiting places where oysters are received in the shell; and, by examining the shells
as they are thrown away, may now and then come across
good specimens.  With a stiff brush and some water the
mud may be washed off the shell, and then the creature will
present the following appearance.
FIG. 139.-BARNACLE ON OYSTER-SHELL. —The circular scar on the shell indicates the place
from which another barnacle had been taken.
The barnacle-shell is round and conical, broad at the
base by which it is firmly attached to the rock or whatever
object it grows upon.  The walls of this shell are composed
of six pieces whose edges overlap each other.  The opening
in the top of the shell is closed by four plates which tightly
fit together.
In collecting these creatures for the purpose of studying
themn alive, care must be taken in breaking them from  the




BIVALVE CRUSTACEANS AND BARNACLES.                 151
rock.  It will be much better to take them from  the wooden
piers, or, if possible, specimens should be collected attached
to some pebble.  These may now  be placed in a jar or bowl
of salt-water; and, if they are watched closely, there will be
seen a set of fringed arms, like hairs, thrust out at the top of
the shell, which, stretching out with graceful crl'yes, close and
partly retract within the opening.  This motion will be constantly and rapidly repeated. There are six pairs of these
appendages, and they are flung out in this way to grasp the
minute particles in the water, which serve them  as food.
Tilhe arms being jointed and fringed with delicate hairs, the
whole combined forms a sort of net.  In Fig. 140, 6, the
tip of one of these arms is shown, highlly magnified.
A                        B. 40.-A, Sie-View of Barnacle, Natural Size, showing Appendages protruded for Food;
3<IC. 140.-A, Side-View of Barnacle, Natusal Size, showting Appendages protruded for rood;
B, Top-View of same closed; C, highly-magnified View of the Tip of one of the Appendages.
137. Inland pupils may break open the barnacles collected
on the oyster-shell, aPnd, taking out the soft partis may examine
them  by placing the parts in water, when the fringed arms
become apparent; and under the microscope the delicate hairs




152                    FIRST BOOK OF ZOOLOGY.
which fringe  the arms may be seen.   The  jointed structure
of these  appendages  and  their  arrangement in  pairs  show
that the creature  does not belong  to  the  shell-fish  or mollusks, as its shell migght seem  to indicate.
In  past times many able  naturalists  classed  these  creatures with  the  mollusks, because  they  judged  from   the  external appearances of the shell, which was limy.   A   careful
study of their anatomy and  development proved  their relations to the crustaceans, and that they had no affinities whatever with the mollusks.   In their growth they moult, in this
act shedding all the skin, and at certain times in the summer
the water will contain  myriads of their cast-off  skins,   The
shell, however, is not shed.
B                    -
FIG. 141.-EARLY STAGES OF A BARNACLE A, shortly after leavning the Egg; e, Eyes B,
having acquired a Bivalve Shell, and just before becoming attached, represented upside
down; C, Appearance after becoming attached —Side-View; D, Top-View of still later Stage,
with the Shell forming around it; E, Side-View of Later Stage, showing Appendages )protruded. (The little marks at the sides of the figures indicate the natural size of the object.
A, B, highly magnified; all of these Views are magnified, and, with the exception of D,
are reduced from figures of C. Spence Bate.)




WORMS.                      153
138. The young come from eggs as iree-swimming animals, fulrnished with eyes and jointed appendages provided
with hairs. In this condition they swim about for a while,
and then acquire a bivalve shell, and in this state remotely
resemble the little creatures shown in Fig. 138.
In Fig. 141, the letter A represents its first appearance
from the egg. Its next appearance with the bivalve shell is
shown at B. After remaining a free-swimmling animal for a
while it becomes attached to the rock, adhering by means of
appendages on the head, and, then moulting, it loses its former
appearance; the appendages change their proportions, new
parts are added, the eyes disappear, a limy shell gradually
forms around it, and it assumes characters entirely unlike
those of its earlier stages.
CHAPTER XX.
woRMSI
139. AxMONG the animals thus far studied, having a body
composed of segments, the pupils have seen that in all cases
the appendages w, ere jointed, that is, the legs and antennae
were composed of distinct segments or joints; and, with the
exception of the myriopods, or centipedes, the animals possessed a limited number of segments to the body.
In the group of animals now to be studied-the wormsthe body has, generally speaking, an indefinite numnber of
segments, and there are no jointed appendages attached to it.




154             FIRST BOOK OF ZOOLOGY.
The most accessible worm  is the common earthworm.
Specimens can be collected by digging for them in damp
earth; and they may be found under almost any board or
rock which has lain for some time.
The worms may be washed by placing them in a bowl
of water, where their movements wAill soon remove the
dirt.
The body is composed of a series of rings or segments,
which are alike in form, except those at the extremities,
which differ. The body tapers at both ends. The forward
or anterior end tapers to a blunt point, while the hinder
end becomes broad and flattened.
By carefully watching the worm when it shortens up
after a long stretch, there will be seen, projecting from the
sides and lower portion of each ring, minute points, which are
the ends of little bristles protruding from openings in the
sides. These bristles as they move project backward.
rIG. 142.-COMMON EARTHWORM.
The worm moves along the ground by the aid of these
bristles, or setce, as they are called. The body alternately
lengthens and shortens. When the body lengthens, the setse




WORMS.                         155
on the hinder segments of the body prevent it stretching
backward, because the setse pointing backward stick into the
ground; the body therefore can only lengthen in one direction, and that is in a forward one.  Then, when the body
shortens, the setse in the forward segments stick into the
ground, and the hinder part of the body is drawn up, and
by this method the creature moves along.
A B
FIG. I43.-EG(G-CAPSULES OF LEECi_, A; AND YouN(u LEEcH, B.-The egg-capsules are
drawn natural size. The young leech, which was taken from the egg-capsule, is drawn
greatly enlarged, the little line above showing its natural size.
140. Another very common worm  is thLe leech.  Specimens may be collected in almost any pond or lake, and kept
alive in jars of water.  The creature is fiat and broad, and
in some species is furnished, at the hinder end of the body,
with a sucker, while others have a sucker at each end
of the body.   It crawls by means of these suckers, and
swims through the water by an u-ndulating movement of the
body.  The eggs of the leech are laid on the leaves and
stems of plants which grow  in the water.  The eggs are
contained in little oval and flattened capsules- and these capsules are laid side by side.  In Figure 143 A  represents two
capsules, in which the little leeches can be seen; and also a
figure of a young leech greatly enlarged, showing the eyes




156             FIRST BOOK OF ZOOLOGY.
and month, at one end, and the sucker at the hinder end.
The body being nearly transparent, the internal organs show
through.
The species of worms in fresh water are few in number
and quite small. The ocean seems to be their true hone,
and all along the sea-coast a great variety of worms —many
of them of large size-occur.
141. Pupils who have access to the sea-coast may collect
them between high and low water mark. Certain species
may be got by turning over stones and others by digging
either in muddy or sandy places.  After a violent storm
from the ocean, many kinds of worms are thrown up, and
may be found in pools left by the receding tide. The roots
of large sea-weeds also afford shelter to certain kinds. All
of these creatures may be kept alive for a few  days,
though considerable care is required, aind those not experienced in keeping salt-water aquaria are warned to exclude
these animals.
They may be best studied by being placed in shallow
bowls or plates, and there will be much to admire in their
graceful motions and curious ways.
142. A very common formn is found Wunder stones at low
tide. The body is composed of a great mally segments,
from the sides of which project little appendages of various
shapes, and also bunches of'bristles which can be plainly
seen as the creature moves. The head, instead of being
simple as in the earthworm, is surmounted by various
feelers.




WORMS.                        157
Another species very common on the sea-shore, under
stones, is much shorter than the one just described.  It has
two rows of oval scales along the back, and the mouth is furFIG. 144.-A CommION SEA-WOWr.
nished  with powerful jaws, which work Up and down.  When
they are placed in alcohol these jaws generally protrude.
14-3. Some species have a curious way of protruding
their cesophagus when they seize their food, at the end of
FIG. 145. —A S.CA-WORM  WITH ScaLEs. —The eyes may be seen, fonr in number, between the
forward scales.
which appear the jaws, like sharp claw-shaped teeth.  The
following figure shows the anterior end of one of these
worms, with the cesophagus protruded, in the act of seuenring its prey.
Certain other sea-wormls build tubes of mud or sand
in which they live, and many of these have bunches of




158                  FIRST BOOK  OF ZOOLOGY.
thread-like feelers on the head.  If these worms are taken
from  their tubes and placed in a plate of sea-water in which
h
rIG. 146.-ANTEItIOR PORTION OF A SEA-WORIN, WTITH THE (ESOPHAGUS PROTRUDED. —-C;,
(Esophagus; j, Jaws; 7h, Head,
are contained also particles of dirt or sand, they will commence
to build  a new tube, and for this purpose the threads on the
head will stretch out like delicate rubber cords, and, becoming
entangled in the particles of dirt, will draw  them  toward the
head, when the appendages on the body will mould it around
them in the shape of a tube.
I    A
FIG. 147.-SEA-Wo RMs  wh-Ich  AIAKE LIMy TUBES.-A-, orm with Irregular Tube, the line
Z indicates natural length; B, Wormn with Spiral Tube, enlarged; C, Piece of Sea-Weed,
showing the Appearance and Natural Size of these Spiral Tubes attached to it.
Other worms deposit a hard, shelly tube of lime.  Some
of these are irregular in shape, as in Fig. 147, iA. Other




WORMS.                        159
species build the tube in a coil, looking very much like a
snail-shell, as in Fig. 147, -B. This form is very common on the
ordinary rock-weed, and may be collected in the debris thrown
up by the waves.  Pupils should collect these, and, if possible, watch the little creatures as they protrude the feathery
appendages which surround the head.  In the forms figured,
one of the appendages is modified into a sort of plug, and,
when the worm retires within the tube, the plug stops up the
aperture securely, as certain snails close the aperture of their
shells with an operculuam.
144. In studying the affinities existing between animals
in order to group them together naturally, the pupils should
learn how unsafe it is to judge by the external appearances of
the animals to be classified.  For example, the little worm B
just described has a coiled, limy shell, which might easily be
mistaken for the shell of a snail. Yet the slightest examination
of the soft parts within shows that the animal is made up of
segments, and that, minute as it is, there are bunches of
bristles, or sete, projecting from the sides of the segments,
and from these and other characteristics the creature is proved
to be a true worm, having no affinities with the snails.  The
barnacles too have a limy shell;'yet, when the creatures
within are examined, their affinities with the crustaceans are
seen at once; and, although distinguished naturalists in past
times grouped them  with the shell-fish, or mollusks, they
properly belong to that class which includes the lobster and
crab.




160               FIRST BOOK OF ZOOLOGY.
CHAPTER XXI.
CONCERNING NATURRAL GROUPS.
145. THE pupils have seen, thus far, that the various creatures studied not only differ greatly in their structure, but that
some are complex or elaborate in their characters, while
others are quite silple.  But, while these animals differ
so mulch among themselves, there are certain characteristics
which many of theml have in common1 as in the crustaceans
and insects, for exanmple, where all of them  had the body
divided into transverse segments, and the appendages were
all jointed. These features, which are conmmon in large assem.
blages of animals, are the essential characters by which they
are brought together into great groups or divisions.  Thus,
all those animals which have the body jointed, that is to say,
divided into a series of segments, as in the worms, crustaceans,
and insects, form tire great branch of Articulates of Cuvier,
because Cuvier, the celebrated French naturalist, first appliecl te name Arteiculctcc to an assemblage of animals which
included the worms, crustaceans, and insects.  Since then
other naturalists have had reason to separate the worms from
the crustaceans and insects, and to classify them. in a great
branch called VTermnes, for worms do not have a continuous
hardened and limy skin covering the body and appendages,
and, generally speaking, the segments cannot be grouped
in regions, as is possible with the crustaceans and insects; the




CONCERNING NATURAL GROUPS.               161
segments are far more numerous, and there is no definite
nunber of them, as in the two last-mentioned classes; the
absence also of jointed appendages and certain features concerning their internal structure, lead some naturalists to recognize, under the name vermes, the worms and related
forms as a branch separate from the crustaceans and insects,
though still having certain features in common with them.
The name' Articulates is therefore abandoned, and the crustaceans and insects are united in one branch, and called
ArthFroyod8s, a word derived from two Greek words, meaning
jointec foot.'The clams, oysters, mussels, snails, and some
other creatures which have not been mentioned in this book,
have certain essential features in common, and so they are
included in another great branch called JLfotl6lsks from  a
Latin wordcl, molis, meaning soft, because the bodies of these
animals are soft.  A very inappropriate name, because there
are many other animals which are soft bodied having no
relation with the shell-fish or Mollusca.
146. Now, these divisions or branches not only include
animals which are simple in their structure, but animals
which are very elaborate.  All the animals in each great
division, however, must embrace creatures that possess the
same essential characters. ~With a knowledge of these essen —
tial features, it has been customary to make a diagram of a
theoretical animal out of these characters only. This theoretical fignure is called an archEetype, meaning an ancient type,
or first type, and the characters composing it are hence called
typ2e-cchacracters, or typical char'cters, and that animal which




162              FIRST BOOK OF ZOOLOGY.
possesses most of these characters, in the plainest manner, is
called a tylfJical animcal.  This mode of presentation applies
as well to smaller groups as to larger ones.  Thus in the
crustaceans, the lobster and crawfish might be called typical
crustaceans, as being the types or representatives of the class,
while a barnacle would certainly not be looked upon as a
typical animal of this class, though belonging to it.  In
the same way an insect without wings would not be looked
upon as a type of the insects, because one of the leading
characters of the class of insects is the possession of wings.
In making systematic tables to show the'relative grade
an animal occupies, the simplest groups may be placed
lowest in the list to indicate their inferior position. For
instance, if the arthropods were to be arranged in a systematic table, those which have no lungs, but gills instead,
would be placed lowest, because it has been found in other
classes of animals that oftentimes the young or immature
animal has gills which are afterward replaced by cavities for
the purpose of breathing air direct, and the immature animal
is regarded as less perfect, or lower in its organization than
the mature or adult form.  Consequently the crustaceans
would be placed lowest in the scale. Then would come the
air-breathing arthropods, and lowest among these would
come the spiders, as the head is not specialized from the
thorax. Next would come the myriopods, as in these the
head is specialized as in the insects.  And, finally, the true
insects would come highest, as here the legs are reduced to
three pairs, the head as well as the thorax is definitely sepa



CHARACTERS OF VERTEBRATES.              163
rated, and now the creature has added to it wings by means
of which it has new means of locomotion.  This, however,
refers only to the most prominent types.
If the table is to be arranged to show the highest animals
in the highest part of the column, it would be arranged as
follows:
Insects.
AIR-3REFATHING ARTTIROPODS. zli~ysr-ioPods.
ARTHRiOPODS.                      pider s.
( WATER-BREATHING ARTHROPODS.  CrZustCceaCns.
This is classification: to classify animals is to bring those
creatures together which have certain leading features in
common. And these classes may be divided again and again
into smaller groups.
As, for example, the insects proper: if the pupils were to
divide them  into smaller groups, the beetles would come
together as one group, no matter what their shape or size;
moths would form another group; the bugs another group,
and so on.
CHIAPTER  XXII.
CHARACTERS OF VERTEBRATES.
147. THE lessons thus far presented have been upon
creatures belonging to three great divisions of the animal
kingldom, the Mollusks, Arthropods, and Worms.  There are
many othler groups which represent other great divisions of
the animnal kingdom, of which no mention has yet been made,




164               FIRST BOOK OF ZOOLOGY.
and upon some of which a few brief lessons will be given.
The mnaterial to be collected for this lesson should consist
either of salamanders (or lizards, as they are incorrectly
termed) or water-newtts.  The salamanders inay be found in
groves and forests, under rotten logs or bark.  They are
absolutely harmless, though many people regard them  as
poisonous.  Water-newts are similar to the salamanders, except that they live in the water, and the tail is often provided
with a fin.
The following figure (Fig. 148) represents a species of
FIG. 148. —COIMOIN YELLOW SPOTTEi) 5 AjLAMANDER.
salamander common to the Northern States, and also found
at the South.  Its color is bluish black, with a row  of irregular shaped yellow spots on each side of the body.
In studying thle external characters of the salamander,
the pupils will observe the following features:




CHARACTERS OF VERTEBRATES.              165
The animal has a head with a slight narrowing between
it and the body. The head has two eyes, capable of being
closed by movable lids.  The mouth opens transversely;
that is, the lower jaw is on the under part of the head, and
moves up and down.  In the insects and crustacea, the jaws
were on the sides of the head and opened sideways.  The
jaws have minute teeth, and in large salamanders the teeth
can be felt by rubbing the finger along the edge of the
mouth.  On the front of the head there are two holes representing the nostrils.  The creature has four short legs, a forward pair and a hinder pair; it has short feet also, with four
toes on each forward foot, and five toes on each hinder foot.
The tail, which is quite as long as the body at its commencement, is nearly as wide as the body, but tapers gradually,
and becomes flattened at its end.
148. How different in every respect is this creature from
the animals thus far studied in this book! and yet, if the salamander is compared with a dog or cat, the characters mentioned above will be found in each.  The cat has also a head
containing two eyes with movable lids; the lower jaw is on
the under part of the head and moves up and down and the
mouth opens transversely; it is furnished with teeth, there are
four legs with feet and toes, and the creature has a tail. But
there are also important differences between the two: the cat
has external ears, while the salamander has none, though it
has parts which enable it to hear.  The cat's skin is covered
with hair and is dry, while the salanander has no hair upon
it and the skin is always moist.  The cat has sharp claws,




166              FIRST BOOK OF ZOOLOGY.
while the salamander now being described has none.  On
touching the cat it feels warm, while the salamander feels
cold to the touch; with the cat the young are born alive, and
the little kittens have the same general features as the parentcat.  The salamander lays a lot of eggs, and most of the
species lay their eggs in the water; when these hatch, the
creatures coming from  them  have no lungs and cannot
breathe air directly, but have gills instead. More curious
still is the fact that, when the young creature hatches from
the egg, it has no legs, these appearing afterward as the animal grows.
The following figure represents the appearance of a young
salamander ten days after hatching from the egg. The gills,
appearing like feathers, are seen on the sides of the neck.
g
FIG. 149.-YoUNG SALAMANDER. —g,, Gills.-(After a figure by Dr. P. R. Hoy.)
149. Thus, while there are important differences between
the cat and the salamander, there are also many points of resemblance; and, if the arrangement of bones constituting the
skeleton be examined,  a still closer resemblance mnay be seen.
Within the body the salamander has a series of bones which
together form the skeleton.  The most important part of the
skeleton consists of a row of bones which runs along the central line of the back of the body from the head to the tip of




CHARACTERS OF VERTEBRATES.             167
the tail.  This row, or column of bones, is called the vertebral
column, and the bones composing it are called the vertebrce.
The bones of the head combined form the skull or craznium.
The ribs, which in the salamander are rudimentary, are attached to the sides of the body vertebrae. The bones of the
fore and hind legs are similar, though they are called by
different names.
A series of bones just back of the head, the longest of
which is the shoulder-blade, forms the pelvic girdle; to this
girdle the first bone of the fore-leg is joined. Other bones at
the hinder part of the body form the pelvic arch, and to this
the first bone of the hind-leg is joined.
150. It will be a difficult task for the pupils to remove
the flesh from  a salamander so as to show the bones united,
and it will also be difficult to prepare the skeleton of a cat;
but the pupils may learn something about the bones and their
attachments by gently handling the creature.  Strauss-Durkheim, a celebrated naturalist, when he was writing his famous
work on the cat, used to hold one of these animals for hours
in his lap, while he felt of the muscles and other portions of
the body.
The following figure of a cat shows the position of the
bones in outline.
Along the back is a series of prominences which indicates
the vertebral column, or, as it is usually called, the backbone
or spine. On the sides of the body the ribs may be felt like
bars or ridges. The shoulder-blades, or ccapulce, are prominent bones, forming the shoulders, and from these the bones
of the fore-legs start.




168                 FIRST BOOK OF ZOOLOGY.
The bones of the pelvic arch, or pelvis, may be readily
detected, and from  these the hind-legs start.
-------------           -------
--—.....    1
------------?    89  65  4
FIG. 150.-CAT, WITHE BONEs OF RIGHT SIDE DRAWN. —C'Oa, Cranium; se, Scapula or ShoulderBlade; 1, Ilumerus; 2, Radius and Ulna; 3, Carpus; 4, Phalanges; 5, Femur; 6, Tibia
and Fibula; 7, Tarsus; 8, Metatarsus; 9, Phalanges; i, Innominate Bone-a number
of Bones combined, forming the Pelvic Arch; v, Vertebral Column.
151. This mode of examining  the bones is suggested,
since it would hardly be possible for pupils to prepare a
proper skeleton, and because few of the museums of the
country to which they would have aceess possess skeletons
of this kind.  Now and then there may be found upon the
beach a nicely-cleaned skeleton of a dog or cat, made so by
little creatures which have fed upon the flesh, and this may
be used for study.
As unlike as the salamander and cat are in some respects,
in many characters, both external and internal, they are remarkably alike.
If one of the body vertebra be examined, there will be
found a central bony mass, in the upper side of which will
be found a hole which is made by the bone growing up from




CHARACTERS OF VERTEBRATES.             169
each side of the bony mass, arching over, and uniting above.
All of the vertebrae, except those in the tail, possess this channel or tube.
Within the skull is a mass called the brain, and running
from  this through a hole in the skull is a long white cord
called the spinal cord or cerebro-spinal cord, and this always
runs along on the back of the spine or vertebral column,
passing through the arch or hole of each vertebra just-described. In fact, the spinal cord is protected from injury by
passing through this bony tube.
These features with various modifications will be found
in all animals having a vertebral column, that is, a central
longitudinal axis either of bone or cartilage above which
runs the spinal cord.
The impulses of the animal to move originate in the
brain and, passing along the spinal cord, run off by means of
nerves, to animate the movements of the muscles. As a proof
of this, if the spinal cord be injured, the parts behind and
below it are rendered helpless.
The ribs passing from the vertebrae arch below, and
form another and much larger cavity, in which are contained
the organs which contribute to the body's growth, such as
the lungs for breathing, the heart for propelling the blood,
the stomach for digesting the food, and so on. The following figure represents a body vertebra to which are attached
a pair of ribs with the cavity above, in which is contained
the spinal cord or cerebro-spinal cord, and the cavity below,
in which are contained the lungs, heart, stomach, etc.
8




170               FIRST BOOK OF ZOOLOGY.
152. If the legs of the salamander are now examined, the
following characteristics will be noticed:
Cavity below,containing lungs, heart,
stomach, etc.
FIG. 151.-A VERTEBRA AND A PAIR OF RIBS, FROM A CAT.-C S, Cavity for Cerebio-spinal
Cord.
If we compare the hind-leg of the salamander with our
own leg, we shall find essentially the same arrangement of
parts, namely: the leg bending at a joint in its middle, or
the knee-joint, and below this joint another one called the
ankle-joint. In that portion of the leg above the knee-joint
there is one long bone called thefemur which joins or articulates with the pelvic arch. In the leg below the knee-joint
there are two long bones side by side, called the tibia and'fibula.  In the ankle-joint there are a number. of small
bones closely packed together; these are called the tarsal
bones, and together form  the tarsus.  In the body of the
foot there are several bones upon which the toes rest, and




CHARACTERS OF VERTEBRATES.           171
these are called the qnetatarsal bones, and together form
the metatarsus; and finally come the bones of the toes called
phalctnges —a long series of names to remember, yet they
apply to every animal possessing a vertebral column and
having legs.
153. The fore-legs of the salamander have similar joints,
the elbow-joint corresponding with the knee-joint, the wristjoint corresponding with the ankle-joint. Above the elbow
there is one long bone called the humerus., and this articulates with the shoulder-blade, or scapula, as it is called. Below the elbow are two long bones side by side, called the
radibus and tulna. In the wrist are a number of small bones
called carpal bones, which together form the cacrpus; and
then follow longer bones corresponding with the metatarsal
bones, and these are called the metacargpal bones, and together form the metacarpus; and finally the bones of the
fingers which are called phalanges, the same name which applies to the bones of the toes. The following figures represent the bones of the right fore and hind leg of a species
of salamander common to the Northeastern and Middle
States.
With the aid of a good hand-lens the pupils may see
these bones in the leg of any small salamander by observing
the following directions: having secured a live salamander,
the animal may be killed with ether; now, if the leg be cut
off and gently pressed between two thin pieces of glass, the
flesh is sufficiently translucent to show all the principal
bones quite distinctly:




172                 FIRST BOOK  OF ZOOLOGY.
|... — femur     hmeu. uzmerus...,fibtula.
t-eb~. —---- tibia,'adius
/Z1zac   ---------... tarsus.           ecarpus
f2'J/9 -  metatarsus. metacarppus __-___   <Q
U>$   W~c\/\ \;9 p7halanges.  phalanges ajo   KI     \
HIIND-LEG.                                FORE-LEG.
FIG. 152.-HIND ANID FORE LEG OF A COMMON WOOD SALAMANDER. (These figures are
greatly enlarged.)
154. All animals possessing a vertebral column have essentially the same external features which have been given
in the preceding lessons on the salamander and the cat; that
is, they have a head containing two eyes with movable lids,
a mouth opening transversely and generally furnished with
teeth; and, with the exception of the snakes and a few other
creatures, possessing  two  pairs of legs-a  fore-pair and a




CHARACTERS OF VERTEBRATES.              173
hind-pair —and internally having a skeleton embracing the
features already noticed.
In the fishes the head is continuous with the body, the
fore and hind legs are represented by fins, one pair directly
back of the head, corresponding with the front-legs, and another pair of fins, which represent the hind-legs, variously
situated behind, below, or even in front of the first pair.
155. The animals which possess a vertebral column, and
hence called Vertebrates (from  the Latin word verto, "I
turn'"), are the fishes, frogs, toads, salamanders, snakes, lizards, turtles, crocodiles, birds, and the warm-blooded, fourlegged beasts, such as the cat, dog, sheep, horse, and elephant.
These last-mentioned creatures belong to a large class of
animals called  acnmalica, the leading features of which are,
that the young are born alive, and the mother nurses the
young.
The fishes, frogs, toads, salamanders, snakes, lizards, turtles, and crocodiles, and others like them, are cold-blooded,
while the birds and mammals are warm-blooded, and all of
them, except the mammals, lay eggs from which their young
hatch.  The fishes, snakes, lizards, and other reptiles are,
generally speaking, covered with scales.  The frogs, toads,
and salamanders, are sm6oth-skinned; the birds are covered
with feathers, while the mammals, with few exceptions, are
clothed with fur.  In the general grouping of the vertebrates the fishes and amphibians-namely, the toads, frogs,
and salamanders-form  one group, the reptiles and birds
form another group, and the mammals a third group.




174             FIRST BOOK OF ZOOLOGY.
With the exception of the fishes, the,, similarity in the
character and arrangement of the bones of the skeleton of
every vertebrate is remarkable. Even the birds, which are
apparently so different from the mammalia on the one hand
and the turtle and salamander on the other, are yet quite
similar to each in the general character and arrangement
of their bones; and if the young bird, while yet in the egg,
is examined, the presence and affinities of certain bones are
very clearly seen.
CHAPTER  XXIII.
BONES OF THE LEG AND WING OF BIRDS.
156. Our pupils have learned by this time how important it is to study the very young animal in order to determine its relationships. Thus in studying the young barnacle the affinities of the creature were more readily recognized, and in the affinities of the parts of the animal, by
studying the young spider the palpi were more easily seen to
be modified legs. Now, as an interesting example of the
necessity of studying the young or early condition of an
animal, a bird is cited.
The fore-leg in the bird is represented by its wing, and
in studying the bones of the wing of an adult bird but little
resemblance can be seen between them and similar parts in
other vertebrates.  The humerus, radius, and ulna are plain
enough, it is true, and, when the pupil has a chance to pick




BONES OF THE LEG AND WING OF BIRDS.             175
the flesh from a chicken's or a turkey's wing, he may observe
these bones easily enough.  The bones of the wrist and
hand, however, seem  to be few  in number and curiously
grown together.
H  R  U
carpus {
metacalrpus 
pohalctanges i
FIG. 153. —RIGHT WING OF AN ADULT BuRD SEEN FROM THE INSIDE. —; Humerus; R, Radius; U Ulna.
157. If, however, a young bird is taken from  the egg
before the parts are fully formed, the bones of the wing
will be found separate and distinct, and the relation between the wing of the bird and the fore-leg of other vertebrates becomes more fully apparent.
So constant are the characters of these parts in all birds,
that a robin, a sparrow, a pigeon, or a chicken, will reveal
the parts quite as distinctly as the larger birds.
In the embryo bird, that is, a bird while still in the egg,
the wing and leg appear far more alike than in the adult, as
may be seen by looking at the following figures of embryo
birds e




176                   FIRST BOOK  OF ZOOLOGY.
A                    B                       C
FIG. 154.-EIMBYO BIRDs IN VARIOUs STAGES OF DEVELOPMENT.-A, Chipping Sparrow;
B, Petrel; C, Tern seen from above.
If, now, the bones of the wing of an embryo bird be examined, the bones of the  extremity of the wing, instead of
humerus -----
radius 
netacarpus  
phalaeges 
FIG. 155.-RIGHT'WING OF AN EMnBRYO BIRD GREATLY ENLARGED.-Only a portion of
the humerus is seen.




BONES OF THE LEG AND WING OF BIRDS.             177
being closely welded together as in Fig. 153, are found to
be separate, and the carpal bones, of which only two were
apparent in the full-grown wing, are now separate and four
in number.  The wing at this stage looks more like a threetoed foot. Fig. 155 shows the appearance of the wing of an
embryo bird.
As the bird develops, the bones of the fingers gradually
approach and some of the bones grow together till they
present the appearance shown in Fig. 153.
158. The bones of the leg grow together in the same way.
fibula
tibia |
tarseus e -...... —''
mIG. 156. —BoNEs OF THE RIGHT LEG OF AN ADULT BIRD. 1Only the lower portion of
the tibia -and fibula is drawn.




178                FIRST BOOK OF ZOOLOGY.
The foregoing figure (see page 177) represents the lower
portion of the leg-bones of a bird.
It will be seen that three of the metatarsal bones, corresponding to the three long toes, are combined; their ends,
where the toes join on, appearing separate, while the metatarsal bone of the short toe on the side remains separate from
the others.
At the ankle-joint, or tarsus, there are no separate tarsal
bones to be seen, nor would their existence be known, except
theoretically, without an examination of the embryo.
The following figure represents the appearance of the leg
---------— fibcta.
- metatacrsus.
O C  i         p7halanyes.
tIG. 1[7. —RIGHXT'LG Or AN EMBRYO BiRD GREATLY ENLARGED. —Only the lower portion
of the tibia and fibula is drawn.




BONES OF THE LEG AND WING OF BIRDS.          179
of an embryo bird greatly enlarged, showing the bones in
place.
At this early stage, not only the metatarsal bones are
seen separate, but the bones of the tarsus, four in number,
are well -marked and distinct.'
The many strange modifications in the shape and proportions of the legs of vertebrate animals are accompanied by
similar changes in the arrangements, number, and proportion
of the bones of these parts.
Thus, in the short leg of the salamander (see Fig. 152)
the bones of the tarsus occupy a space about as long as that
of the metatarsus. In birds, on the contrary, the tarsus is
very short, while the metatarsus is very long.
159. If the pupils will observe the hind-leg of the toad
or frog, it will not only be seen to be much longer than the
fore-leg, but an extra joint seems to be added in the foot.
An examination of the bones shows that the first two tarsal
bones are very long, while the other tarsal bones are very
short; so that in this case the tarsus combined is much longer
than the metatarsus.  The following figure represents the
right hind-leg of a. young toad while still in the tadpole
state, though the adult shows the same features.
The above brief lessons on the vertebrates do not even
embrace an outline of the structure and habits of any of
the classes, and they are given only as suggestions toward a
method of study, and to point out the essential paths to fol1 The author has seen the tarsal bone, marked i, in the heron, tern, and seapigeon.




180                FIRST BOOK OF ZOOLOGY.
low) in order to gain an insight into the affinities existing
between the various groups composing this great branch of
animals.
-2     fibula.
-------- tibia.
tarsus,
lmetataresse,
D O    I phalanges,
FIG. 158.-BoNEs OF THE RIG1T LEG OF A YOUNG TOAD GREATLY ENLARGED. —The femru
is not shown in this drawing; the tibia and fibula are combined together.
There are still other large classes of- animals forming
branches or sub-kingdoms quite distinct from  those already
studied, and represented by animals which live in the sea,
such as the star-fish, sea-urchin, jelly-fish, and sea-anemone,
of which no mention will be made in this book.  There are
also many classes, belonging  to branches already touched
upon, which have not been alluded to.  These will be fully
dealt with in the second book, now in preparation.




CLASSES AND SUB-KINGDOMS.             181
CHAIPTER XXIV.
CLASSES AND SUB-KINGDOMS.
TRE following figures illustrate the classes and sub-kingdoms which have been dealt with in this book, with their
technical names:
SUB-KINGDoM MOLLUSCA (Clams, Snails, Squids, etc.).
Class Casteropoda (snails, periwinkles, limpets, etc.).Animals whose bodies are generally inclosed in a mantle or
sac, which usually secretes a shell composed of one piece, and
this often assuming a spiral shape.  The body rests upon a
broad, creeping disk called the foot, and this part represents
the ventral portion or belly of the animal.  The name Gasteropodac is derived from two Greek words, qaster, the belly,
and pous, foot. The following figures represent a few animals of this class:
/




182              FIRST BOOK OF ZOOLOGY.
GASTEROPODS.
Class Acepkala (clams, oysters, mussels, etc.).-Animals
whose bodies are protected by a mantle which secretes a bivalve shell, or a shell composed of two pieces.  They have
no well-defined- head, and hence the name Acephala, derived from two Greek words, a, without, and cephale, head.
These animals are also called iamellibranchiates, because
the gills form leaf-like membranes or plates on the sides of
the body; the word being derived from a Latin and a Greek
word, lamellac  a plate, and branchia, gill. The following
figures represent a few animals of this class:
*~~~~~~~~~1,= j.




CLASSES AND SUB-KINGDOMS.              183
ACEPHALA.
IUB-IKINGDoM ARTHROPODA (Insects, S2pders, Centipedes,
-rabs, etc.).
Class Insecta (beetles, bugs, butterflies, etc.).-Animals
iose bodies are made up of segments grouped together in
ree regions, the head, thorax, and abdomen; having three
irs of jointed legs, and one or two pairs of wings, and
eathing air through openings in the sides of the body.
ie word insecta comes from a Latin word, inseco, I cut into,
ferring to the distinct separation of the body into regions.
54




184             FIRST BOOK OF ZO(ILOGY.
TISECTS.
Class 2yriopoda (centipedes, millepedes). Animals comni
posed of many segments. These not apparently combined
into regions, except the head, which is distinct. The numnber
of pairs of legs coinciding with the number of segments.
Breathing air through openings in the sides of the body.
The word mnyriopoda is derived from two Greek words,
murios, ten thousand, and pous, foot.
A MYRIOPOD.




CLASSES AND SUB-KINGDOMS.           185
Class Arachnicda (spiders).  Animals whose bodies are
segmented. The segments grouped together into two regions,
the cephalo-thorax and abdomen. Haviang four pairs of
legs, and breathing air through openings in the body.
The word arachnida is derived from  a Greek word,
arachne, spider.
ARACHNIDS.
SuB-KINGDOM VERME5s (worms).  Class Annenida (angleworms, leeches, certain sea-worms, etc.).  Animals whose
bodies are made up of an indefinite number of segments,
bearing appendages which are not jointed, and in the larger
number of groups having bunches of bristles or setce upon
the sides of the body which act as supplementary organs of
locomotion. The name annelida is derived from the Latin
word annnlus, a ring.




186              FIRST BOOK OF ZOOLOGY.
WORMS.
Class Crustacea (lobsters, crabs, barnacles, etc.). Diffieu
to define, but including animals which pass through a seri(
of moults in their growth, though in this respect resemblin
the spiders, and breathing by means of gills, and in th
respect differing from other artrogpods.




CLASSES AND SUB-KINGDOMS.                187,
CRUSTACEANS.
SUB-KINGDOM  VERTEBrATA, with the following classes,
which were only briefly alluded to: FisAes, Avmphibians,
Reptiles, -Birds, lTraamals.  According to a late classification of Professor Huxley's, these classes would stand IcfAthyopsida, which includes the Fishes and Amphibians; Stu



188               FIRST BOOK OF ZOOLOGY.
ropsidca, which includes the Reptiles, and Birds; and 1
iXammalia.
Ickthyopsida is derived from  two Greek words, ick
a fish, and op8i8, appearance.  Sauropsidct comes from
Greek words, scauros, a lizard, and opis, appearance.
VERTEBRATES.




N OTICE TO TEACHERS.
To those who care to pursue the subject more in detail with
their classes, or to present the history of those groups of animals of which no mention has been made in this book, the
author would suggest the following publications, among many
others of value, as works of reference:
Woodward's Manual of Mollusca.
Marine Mammalia and American Whale-Fishery. By Captain C. M. Scammon,
U. S. R. M.
Sea-side Studies in Natural History.  By Mrs. Agassiz and Alexander Agassiz.
Corals and Coral Islands. By Prof. J. D. Dana.
Packard's Guide to the Study of Insects.
Insects injurious to Vegetation. Harris.
The Annual Reports of. the State of Missouri on the Noxious, Beneficial, and
other Insects. By Prof. C. V. Riley.
United States Fish Commissioners' Report for 1871-"72. By Prof. Spencer F.
Baird. Containing valuable illustrated chapters on the Mollusca, Crustacea,
WVorms, etc., by Prof. A. E. Verrill and S. I. Smith.
Key to North American Birds. By Dr. Elliot Coues, U. S. A.
Osteology of Mammalia. Flower.
A History of North American Birds. By Baird, Brewer, and Ridgeway.
Canadian Entomologist.
Forms of Animal Life. Rolleston.
Methods of Study in Natural History. By Prof. L. Agassiz.




190                    NOTICE TO TEACHERS.
And for general information, the works of Darwin, Huxley,
Owen, Wallace, Mivart, Lubbock, and the  Duke of Argyle,
and also
Nature, a weekly magazine published in London, and containing an infinite
variety of contributions from English and Continental naturalists.
The American Naturalist, a popular illustrated magazine of natural history.
Edited by Dr. A. S. Packard and F. W. Putnam, and published in Salem, Massachusetts; containing a vast amount of information by Lockwood, Allen, Coues,
Verrill, Smith, Stearns, Scudder, Emerton, Gill, Putnam, Packard, Hyatt, Mann,
Marsh, Dall, Cooper, Gill, Cope, Ridgeway, Wood, Abbott, Trippe, Le Conte,
Wyman, Dawson, Grote, Mayer, Gentry, Shaler, Wilder, Aikin, Treat, Perkins,
Riley, Agassiz, Dana, Hill, Uhler, Edwards, Tuttle, Tenney, Ward, Hagen, Hartt,
Shimmer, Hartshorne, Ritchie, Tilsdale, Hoy, Orton, Lewis, Leidy, Brigham,
Scammon, Binney, Stimpson, Collins, Fowler, Walker, Jordan, Wright, Norton,
Maynard, Canfield, Fellowes, Endicott, and others.
The Popular Science Monthly, edited by Prof. E. L. Youmans, and published
by D. Appleton & Co., New York; containing valuable illustrated articles by
American and European naturalists.
Every school library should, if possible, contain a complete set of Nature, the
Naturalist, and The Popular Science Monthly. For special descriptions of species,
the miscellaneous collection of the Smithsonian Institution, with contributions
by Stimpson, Gill, Bland, Binney, Prime, Tryon, and others. Also the American
Journal of Science and Art, and the publications of the Boston Society of Natural History, Philadelphia Academy of Sciences, New York Lyceum of Natural
History, Buffalo Academy of Natural Sciences, California Academy of Natural
Sciences, Portland Society of Natural History, Museum of Comparative Zoology,
Peabody Academy of Science, etc.
All these last-named publications should be found in the
larger libraries of the country.
THE END.




Appletons' Standard Scientific Text-Books
Youmans's First Book of Botany.  Designed to cultivate the Observing
Powers of Children. By ELIZA A. YOUMANS. 12mo. I83 pages. $I.oo.
This little book has proved a wonderful success, and is emphatically a step in the
right direction. Although it has been issued but a short time, it has been adopted for
use in the cities of Chicago, St. Louis, New York, Columbus, Nashville, Milwaukee,
etc., etc., and in the States of Maryland, Illinois, and Arkansas. It is to be speedily
followed by the Second Book of Botany and six large and beautifully-colored Botanical
Charts, after the plan of Henslow.
Hon. Superintendent Bateman, of Illinois, says: "As a sample of the trute method
of teaching the elements of science in primary schools, Miss Youmans's book is deserving of the highest praise. In this respect I have seen nothing equal to it. The same
method, pursued in all the natural sciences, would soon give us a generation of accurate and intelligent young observers of natural objects and phenomena, and change for
the better the whole tone and character of common-school instruction.
" NEWTON BATEMAN, Snf/ t Public Instruction.'
Lockyer's Astronomy, accompanied with numerous Illustrations, a Colored
representation of the Solar, Stellar, and Nebular Spectra, and Celestial Charts of
the Northern and the Southern Hemispheres. A uzerican.Edition, revised and
specially adapted to the Schools of the United States. I2mo. 312 pages.
Quackenbos's Natural Philosophy.  Revised Edition.  Embracing the
most recent Discoveries in the various Branches of Physics, and exhibiting the
Application of Scientific Principles in Every-day Life. Adapted to use with or
without Apparatus, and accompanied with Practical Exercises and numerous Illustrations. 12mo. 450 pages.
Quackenbos's Philosophy has long been a favorite Text-Book. To those who have
used it, no words of commendation are necessary; to those who have not, we would
earnestly suggest a careful examination of its claims. We would here merely say that
it has recently been THOROUGHLY REVTSED, in view of recent discoveries in Physics,
and the general acceptance of new theories respecting Heat, Light, and Electricity,
the Correlation and Conservation of Forces, etc. The present Edition is in all respects
an accurate exponent of the present state of science.
-Huxley and Youmans's Physiology.  The Elements of Physiology and
Hygiene. A Text-Book for Educational Institutions. By THOMAS H. HUXLEY,
F. R. S., and WILLIAM JAY YOUMANS, M. D. I2mo. 420 pages.
Nicholson's Text-Book of Geology. Well condensed, accurate, and clear.
12mo. 266 pages.
Nicholson's Text-Book of Zoology. A comprehensive Manual for the use
of Academies and Colleges. By Prof. NICHOLSON, of Toronto. I2mo. 353 pages.
Wrage's German Grammar: based on the Natural Method-L~aeguage before Gcezmnulzar. Teaches German rapidly, pleasantly, and thoroughly. I2mo.
350 pages.
Krusi's New Series of Drawing-Books: Teacher's Manual, and Synthetic
Series of Inventive Drawing (4 Nos.), now ready. Something new and excellent
-one of the most valuable and efficient of educational agencies.
Send, for Catalogues and further information, to
D. APPLETON  & CO., 549 & 551 Broadway, N. Y.




ID. APPLET'ON c CO.' S iPUBLICAz TIONTS.
Lockyer's Astronomy.
AIiERICA1N EDITION.
"This is by far the clearest and best manual of Astronomy we
have ever seen.   A  child may understand it-and  yet
it contains information which will be new  to
all who have not time to follow  the
latest  discoveries." -  Niew
York Daily Times.
The opinion of the critic of the TiYnes, given above,
is that of all who have examined this sterling schoolbook, which is winning golden opinions everywhere.
Out of hosts of letters, we have space for the following
only:
"Loclkyer's Elements of Astronomy is a work of rare excellence. As a text-book for
the use of schools it is mtnrspaassecl by any work on that subject with which I am acquainted."-Pnor. JOHN S. HART, State Normal School, Trenton, N. A.
"I think it an excellent work —well calculated for class use by pupils of an academic
grade. The arrangement and typography are worthy of especial commendation. It is
a decided success."-S. B. HowE, Stept. of Schools, Schenectadly, N; Y.
"It is the best school-book on Astronomy that I ever saw. The spectra of the sun,
stars, and nebule, are worth the price of the book. The diagrams are excellent. I
deem it superior to all other books on that science with which I am acquainted. Of
course I shall use it." —W. HT. PITT, A. il., Prise. Frioeeldship Academy.
"I have examined with much satisfaction the admirable elementary treatise on Astronomy by Lockyer. It furnishes the reader with the means of learning in a short
time the great features of the modern progress of Astronomy. No book (except, perhaps, Youmans's New Chemistry) has appeared, which so easily, yet thoroughly, prepares the reader for the subsequent study of that mighty auxiliary to modern sciencespectrum-analysis. Moreover it presents, in a clear and succinct style, the relations of
the various parts of the stellar universe, besides inducting the learner into that neglected
branch of Astronomy known as Geography of the Heavens. Its illustrations are genuine aids to the comprehension of the subject-matter."-DAvID BEATTIE, Ss2et. Troy
NV. Y.) City Schools.
"I have examined it with care, and fin dd it admirably adapted for use in schools. It
is so plainly written and so fully illustrated as to render it specially suited for beginners
in the science, and, at the same time, profitable for advanced students.'"-PRno. C. STAy
LEY, Ussione College.
"It is a clear and beautiful unfolding of a profound and fascinating subject.  It
seems to me admirably adapted to the academic grade of students. Not attempting to
discuss those problems and theories of the science for which such pupils have neither
the time nor the capacity, the author has given an outline of the subject that is clear,
sufficiently complete, and thoroughly modern."-PRoF. BRADLEY, Priqnc. Albany Free
Academy.




THE FIRST BOOK OF BOTANY
Designed to cultivate the Observing Powers of Children.
]By IELIZA A. YOUIJIMANeS.o
Price, $1.
This book is incontestably superior to all others of its kind, in two essen
tial respects:
FIRST, it is the best book for all beginners in botany, whatever their age,
because the rudiments of the subject are reduced to their utmost simplifica
tioni, and all the study is upon plants themselves. To study botany without
studying plants is a mockery of education, because it leads not to real
l7nowledge, but to sham knowledge. Miss Youmans's book involves the
study of the plants from the beginning to the end; the book being only a
guide and a help.
SECOND, this First Book of Botany is the only school-book we have, that
provides systematically for the cultivation of the observing powers of children, It practises them in noticing, searching, comparino', dnd reasoning.
with reference to objects themselves-the most important and neglectedi
part of our mental culture. In short, the plan of this book combines the
practical acquisition of one of the most fascinating and uselful of the
sciences, with that kind of intellectual training which it should be the highest purpose of education to confer.
0friom Prof. JoHN S. HART, Principal of the Trenton Normal c/lwosil..This little book seems to me to supply the very thing needed in our
course of primary instruction. I refer not to the study of botany, bult to the
method of studying it here developed. We have here a fourth fundamental
branch of study, which shall afford a systematic training of the observing
powers; and its general introduction into our primary schools would work
a great and most important revolution in our whole system of education.
From the Nation.
We must award the unpretending work of Miss Youmalns high praise.
The authoress has unquestionably the true conception of the duty of the
teacher. Every effort is made to keep the attention of the student upon the
object to be studied, and so well has she succeeded that one may safely say
that the student can do nothing with the book unless he has the specimen
in hand. The plan is so arranged as to be suitable for a priiuary school,
but the method is one which may apply to the college as well. We heartily
recommend every teacher in any department of natural science, who is wise
enough to doubt the perfection of his methods, to look over this book.
Fr1om EDWARD SMITH, Superintendent of School, Syracuse, 1V. Y.
Miss Youmans's Botany is the only work I have ever seen that meets the
wants of our schools in the lower grades. I believe it will do more to turn
the attention of instructors into the proper channel for the education of
children than any thing heretofore published.
From Prof. WmT. F. PHELPS, Principal of the Normal School, Winolna, Minn.
I am delighted with this little worl.  It gives us a sciestific plan for the development of tile observing powers of the young. Send us at once 150 copies.
After using it several weeks, Prof. Phelps thus closes an elaborate notice
of the-book in the Winona Republican:
Every class in the institution is now devoting a regular portion of its
time, daily, to this study pursued in this practical way. The results thus
far are highly satisfactory. It hacs azoakened a new interest in study th'aoughoMt the school. Many, who have heretofore been indifferent in their work,
have taken hold withl great zeal, and are pursuing this fascinating branch
with ardor and enthusiasm. It is no uncommon spectacle to see children
occupying' theih play-hours with a bunch of plants, and, book in hand, pursalng this study as a pastime. This, surely, is an unerring test of its value,
ias it is the highest recommendation that could be given of its adaptation tan
the wants of our primary schools.




INTERNATIONAL SCIENTIFIC SERIES.
NVO IR  EAD Y.
No. 1. FORME.S; O:F WATER, in Clouds, Rain, Rivers, Ice, and Glaciers. By
Prof. JOHN TYNDALL, LL. D., F. R. S. I vol. Cloth. Price, $s.So.
No. 2. PIHYSICS AND POLITICS; or, Thoughts on the Application of the
Principles of " Natural Selection" and " Inheritance " to Political Society.
By WALTER BAGEHOT, Esq., author of "The English Constitution."  I
vol. Cloth. Price, $I.5o.
Lo. 3. FOODS.  By EDwARD SMITH, M. D., LL. B., F. R. S.  I vol. Cloth
Price, $I.75.
No. 4. ]VI1IND  AND  BODY. The Theories of their Relation. By ALEX.
BAIN, LL. D., Piofessor of Logic in the University of Aberdeen. I vol.,
i2mo. Cloth. Price, $I.50.
No. 5. THE STUDY OF SOCIOLOGY.  By HERBERT SPENCER. Price,
$I.50.
No. 66.THJ:IE NEW  CHEMISq TRY. By Prof JOSIAH P. COOKIE, Jr., of Harvard University. I vol., I2mo. Cloth. P-ice, $2.00.
No. 7. THEE C1ONSERVATION OF ENEIRGY. By Prof. BALFOUR
STEWART, LL. D., F. R. S. I vol., Irmo. Cloth. Price, $T.50.
No. 8. ANIMAL  LOCOMCNOTION; or, Walking, Swimming, and Flying,
with a Dissertation on Aeronautics. By J. BELL PETTIGREW, M. D.,
F. R. S., F. R. S. E., F. R. C. P. E.  I vol., I2mo.  Fully illustrated,
Price, $I-75.
INo. 9. RESPONSIBILITY  IN  DI:ENTAL  DISEASE. By HENRY
MAUDSLEY, h. D. I vol., I2mo. Cloth. Price, $I.5o.
No. 10. THIIE SCIENCE O:F LAW. By Prof. SHELDON AMOS. I vol., I2mo.
Cloth. Price, $I.75.
No. 11. ANIIVMAL  ib'NECIHANISlX. A Treatise on Terrestrial and Aerial
Locomotion. By E. J. MAREY. With II7 Illustrations. Price, $I.75.
No. 12. THE HISTORY OF THE CONFLICT BETWEEN RELIGION  AND  SCIENCE.  By JOHN Wma. DRAPER, M.D., author
of "'The Intellectual Development of Europe."  Price, $I.75.
No. 13. THE DOCTRINE OF DESCENT AND DARWINISX.
By Prof. OSCAR SCHMIDT, Strasburg University. Price, I.5o.
No. 14. THE CHEXIISTRY OF LIGHT AND PHOTOGREAPHY.
In its Application to Art, Science, and Industry. By Dr. HERMANN VOGEL. iOO Illustrations. Price, $2.00oo.
No. 15.:FUN:GI; their Nature, Influence, and Uses. By M  C. COOKE, M. A.,
LL. D. Edited by Rev. M. J. BERKELEY, M. A., F. L. S. With  og9
Illustrations. Price, $. 50.
No. 16. THE LIFE AND GROlWTTH OF LANGUAGE. By Prof.
W. D. WHITNEY, of Yale College. Price, $I.50.
No. 17. THIE NATURE  OF LIGHT, with a General Account of Physical
Optics. By Dr. EurGENE LOMMEL, Professor of Physics in'the University
of Erlangen. With i88 Illustrations and a Plate of Spectra in Chromolithography. (Ioz press.)
D. APPLETON  & CO., PUBLISHERS, 549 & 55I Broadway, N. Y.




Internatioona   Scientific  Series.
D. APPLETON & Co. have the pleasure of announcing that they have made arrange.
msents for publishing, and have recently commenced the issue of, a SmRIES OF POPULAR
MONOGRAPHS, or small works, under the above title, which will embody the results of
recent inquiry in the most interesting departments of advancing science.
The character and scope of this series will be best indicated by a reference to the
names and subjects included in the subjoined list, from which it will be seen that the
cooperation of the most distinguished professors in England, Germany, France, and the
United States, has been secured, and negotiations are pending for contributions from
other eminent scientific writers.
The works will be issued in New York, London, Paris, Leipsic, Milan, and St.
Petersburg.
The INTERNATIONAL SCIENTIFIC SERIES is entirely an American project, and was
originated and organized by Dr. E. L. Youmans, who spent the greater part of a year
in Europe, arranging with authors and publishers. The forthcoming volumes are as
follows:
Prof. LOMMEL (University of Erlangen),  Prof LACAZE-DUTHIERS, Zoology szice
O0tics. (In press.)                     Czvzer.
Rev. M. J. BERKELEY, M. A., F. L. S.,  Prof. BERTHELOT, Chemical Synthesis.
and M. CooKIE, M. A., LL. D.,  Prof. J. ROSENTHAL, General Physiology
Fzuzgi; tcir Nlature,.cflnzences,     of Mutuscles crnd Nerves.
and Uses. (In press.)                Prof. JAMESD. DANA, M. A., LL. D., On
Prof. W. KINGDON CLIFFORD, M. A., The        Ceplhalznaltonz, or, Head-Characters
FirstPrnzciziles of /he Exact Sciences   in the Gradations and Progress of
exrlained to the eon-manchenatlical.    LIife.
Prof T. H.. HUXLEY, LL. D., F. R. S.,  Prof. S. W. JOHNSON, M. A., On the NctBodily JMotionz andz Cocnsciouzsness.   tritionz of Plants.
Dr. W. B. CARPENTER, LL. D., F. R. S.,  Prof AUSTIN  FLINT, Jr., M. D., The
The Physical Geograpmhy of the Sea.     Nervous Systez and its Relation to
Prof. WILLIAM ODLONG, F. 1<. S., The Old    the Bodcily Fztctionzs.
Chemisltry viewed fromc tIhe New   Prof. W. D. WHITNEY, Modern LicnguZssStanfcioznIt.                           tic Scientce.
W. LAUDER LINDSAY, M. D., F. R. S. E.,  Prof. C. A. YOUNG, Ph. D. (of Dartmouth
Mind icz the Lower A ncliczals.          College), The Sezn.
Sir JOHN LUBBOCK, Bart., F. R. S., The  Prof BERNSTEIN (University of I-alle),
A ntziqity of AlMat.                     Phzysiology of the Secnses.
Prof. W. T.'1HISELTON DYER, B. A.,  Prof. FERDINAND COHN (Breslau UniverB. Sc., FormSz and Habi/ it Flower-     sity), T/zallohgytes (Algee, Llchencs,
izog Planels.                           Fuccngi).
Mr. J. N. LOCKYER, F. R. S., SpectrVcZ      Prof. HERMANN (University of Zurich),
A nalysis.                               Reshirantioe.
Prof MICHAEL FOSTER, M. D., Proto-  Prof. LEUCKART (University of Leipsic),
psllzac aczd the Cell Theory.            Oucli/nes ofA cctczal O-rgaiZZZalZoZ.
Prof W. STANLEY JEVONS, Moccey: and   Prof. LIEBREICH  (University of Berlin),
thIe Mlechanismcz of Exc/hzange.         Occlinles of Toxicology.
HI. CHARLTON BASTIAN, M. D., F. R. S.,  Prof. KUNDT (Ulliversity of Strasburg),
The BraItin. as anZ Orncazr of Miznd.   O0z Socncd.
Prof. A. C. RAMsAY, LL. D., F. R. S.,  Prof. REES (University of Erlangen), On
Earth  Sczlrltlere: Hills, Valleys,     Prasitlc Placnts.
laozclanzs, PZlazis, Rivers, Lakes;   Prof. STEINTHAL (University of Berlin),
how thZey zere prodtcedc, aczd how      Ouzlznes of the Sciezce of Langutage.
tIey have beecn destroyed.           E. ALGLAVE (Professor of Constitutional
Prof. RUDOLPH VIRCHOW (Berlin Univer-       and Administrative ILaw at Douai, and
sity), Mlorbic  PhysiologicaZ A ctlon.  of Political Economy at Lille), The
Prof. CLAUDE BERNARD, Physical and          Primsmilive Elemeezts of Political ConMela/bhysical Phezomzena of LIfe.       stitztzcons.
Prof. H. SAINTE-CLAIRE DEVILLE, An t  P. LORAIN (Professor of Medicine, Paris),
IctroducIion to General Chezmistry.    Mhloderen E/iidesczlcs.
Prof WURTZ, Atocmcs ancd the Atonzic  Prof. SCIHitTZENBERGER (Director of the
Th eory.                                Chemical Laboratory at the Sorbonne),
Prof. DE  QUATREFAGES, The NVegro           On Fernmentactonzs.
Races.                               Mons. DEBRAY, Precicozs AMetals.




Opiinions of the Press on the  "CInternational  Scientific Series."'
I.
Tyndall's Forms of Water.
I vol., I2mo.  Cloth.  Illustrated.                              Price, $I.50o
" In the volume now published, Professor Tyndall has presented a noble illustration
of the acuteness and subtlety of his intellectual powers, the scope and insight of his
scientific vision, his singular command of the appropriate language of exposition, and
the peculiar vivacity and grace with which he unfolds the results of intricate scientific
research."-N. Y. Trif&zsle.
"The'Forms of Water,' by Professor Tyndall, is an interesting and instructive
little volume, admirably printed and illustrated. Prepared expressly for this series, it
is in some measure a guarantee of the excellence of the volumes that will follow, and an
indication that the publishers will spare no pains to include in the series the freshest investigations of the best scientific minds. "-Bostoz yourhzal.
" This series is admirably commenced by this little volume from the pen of Prof.
Tyndall. A perfect master of his subject, he presents in a style easy and attractive his
methods of investigation, and the results obtained, and gives to the reader a clear con,
ception of all the wondrous transformations to which water is subjected."- Chzsrchsznan.
II.
Bagehot's Physics and Politics.
I vol., I2o.  Price, $s.5o.' If the' International Scientific Series' proceeds as it has begun, it will more than
fulfil the promise given to the reading public in its prospectus. The first volume, by
Professor Tyndall, was a model of lucid and attractive scientific exposition; and now
we have a second, by Mr. Walter Bagehot, which is not only very tlucid and charming,
but also original and suggestive in the highest degree. Nowhere since the publication
of Sir Henry Maine's'Ancient Law,' have we seen so many fruitful thoughts suggested in the course of a couple of hundred pages.... To do justice to Mr. Bagehot's fertile book, would require a long article. With the best of intentions, we are
conscious of having given but a sorry account of it in these brief paragraphs. But we
hope we have said enough to commend it to the attention of the thoughtful ieader."Prof. JOHN FISKE, in the A taZntic lad/ltz7y.
"Mr. Bagehot's style is clear and vigorous.  We refrain from giving a fuller account of these suggestive essays, only because we are sure that our readers will find it
worth their while to peruse the book for themselves; and we sincerely hope that the
forthcoming parts of the'International Scientific Series' will be as interesting." —
A thednweusnz.
"Mr. Bagehot discusses an immense variety of topics connected with the progress
pf societies and nations, and the development of their distinctive peculiarities; and his
book shows an abundance of ingenious and original thought."-AL.FRED RUSSELL
WALLACE, in Nnaltre.
D.. APPLETON  &  CO., Publishers, 549 & 55I Broadway, N. Y.




f)jinions of the Press on the "Inlernaional Scientzifc Series."
III.
Foods.
By Dr. EDWARD SMITH.
I vol., I2mo.  Cloth.  Illustrated........  Price, $I.75.
In making up THE INTERNATIONAL SCIENTIFIC SERIES, Dr. Edward Smith was selected as the ablest man in England to treat the important subject of Foods. His services
were secured for the undertaking, and the little treatise he has produced shows that the
choice of a writer on this subject was most fortunate, as the book is unquestionably the
clearest and best-digested compend of the Science of Foods that has appeared in our
language.
" The book contains a series of diagrams, displaying the effects of sleep and meals
on pulsation and respiration, and of various kinds of food on respiration, which, as the
results of Dr. Smith's own experiments, possess a very high value. We have not far
to go in this work for occasions of favorable criticism; they occur throughout, but are
perhaps most apparent in those parts of the subject with which Dr. Smith's name is especially linked."-Lozfdon Ex.zaminer.
" The union of scientific and popular treatment in the composition of this work will
afford an attraction to many readers who would have been indifferent to purely theoretic
cal details.... Still his work abounds in information, much of which is of great value,
and a part of which could not easily be obtained from other sources. Its interest is decidedly enhanced for students who demand both clearness and exactness of statement,
by the profusion of well-executed woodcuts, diagrams, and tables, which accompany the
volume.     The suggestions of the author on the use of tea and coffee, and of the various forms of alcohol, although perhaps not strictly of a novel character, are highly instructive, and form an interesting portion of the volume."-N-. Y. Tribune.
IV.
Body and Mind.
THE THEORIES OF THEIR RELATION.
By ALEXANDER BAIN, LL. D.
I vol., I2mo.   Clothl............   Price, $1.50.
PROFESSOR BAIN is the author of two well-known standard worlks upon the Science
of Mind-" The Senses and the Intellect," and " The Emotions and the Will." He is
one of the highest living authorities in the school which holds that there can be no sound
or valid psychology unless the mind and the body are studied, as they exist, together.
" It contains a forcible statement of the connection between mind and body, studying their subtile interworlkings by the light of the most recent physiological investigations. The summary in Chapter V., of the investigations of Dr. Lionel Beale of the
embodiment of the intellectual functions in the cerebral system, will be found the
freshest and most interesting part of his book. Prof. Bain's own theory of the ccnnection between the mental and the bodily part in man is stated by himself to be as follows:
There is'one substance, with two sets of properties, two sides, the physical and the
mental-a doable-fared tnizzty.' While, in the strongest manner, asserting the union
of mind with brain, he yet denies'the association of union zin place,' but asserts the
union of close succession in time,' holding that'the same being is, by alternate fits, under extended and under unextended consciousness."'-CrZistian Register.
D. APPLETON  & CO., Publishers, 549 & 55I Broadway, N. Y.




Opinions of the Press on th/e "f Inzernational Scienziic Series."
V.
The Study of Sociology.
By HERBERT SPENCER.
I vol., Izmo.  Cloth.............    Price, $1.50.
"The philosopher whose distinguished name gives weight and influence to this volume, has given in its pages some of the finest specimens of reasoning in all its forms
and departments. There is a fascination in his array of facts, incidents, and opinions,
which draws on the reader to ascertain his conclusions. The coolness and calmness of
his treatment of acknowledged difficulties and grave objections to his theories win for
him a close attention and sustained effort, on the part of the reader, to comprehend, follow, grasp, and appropriate his principles. This book, independently of its bearing
upon sociology, is valuable as lucidly showing what those essential character istics are
which entitle any arrangement and connection of facts and deductions to be called a
scienrce."-Erz'scopirzlza.
" This work compels admiration by the evidence which it gives of immense research, study, and observation, and is, withal, written in a popular and very pleasing
style. It is a fascinating work, as well as one of deep practical thought."-b'os/. Post.
" Herbert Spencer is unquestionably the foremost living thinker in the psychological
and sociological fields, and this volume is an important contribution to the science of
which it treats.... It will prove more popular than any of its author's other creations,
for it is more plainly addressed to the people and has a more practical and less speculative cast. It will require thought, but it is well worth thinlillg about." —lbany
Eveezning _onzrrouzl.
VI.
The New Chemistry.
By JOSIAH P. COOKE, JR.,
Erving Professor of Chemistry and Mineralogy in Harvard University.
I vol., I2mo.  Cloth......              Price, $2.00.
" The book of Priof. Cooke is a model of the modern popular science work. It has
just the due proportion of fact, philosophy, and true romance, to make it a fascinating
companion, either for the voyage or the study."-Daily Graphic.
" This admirable monograph, by the distinguished Erving Professor of Chemistry
in Harvard University, is the first American contribution to'The International Scientific Series,' and a more attractive piece of work in the way of popular exposition rupon
a difficult subject has not appeared in a long time. It not only well sustains the character of the volumes with which it is associated, but its reproduction in European countries will be an honor to American science." —NAeeo Yo-' Tribuizzrze.
"All the chemists in the country will enjoy its perusal. and many will seize upon it
as a thing longed for. For, to those advanced students who have kept well abreast ol
the chemical tide, it offers a calm philosophy. To those others, youngest of the class,
who have emer-ed from the schools since new methods have prevailed, it presents a
generalization, drawing to its use all the data, the relations of which the newly-fledged
fact-seeker may but dimly perceive without its aid.   To the old chemists, Prof.
Cooke's treatise is like a message from beyond the mountain. They have heard of
changes in the science; the clash of the battle of old and new theories has stirred them
from afar. The tidings, too, had come that the old had given way; and little more than
this they knew.... Prof Cooke's'New Chemistry' must do wide service in bringinlg
to close sight the little known and the longed for.  As a philosophy it is elerrmern
tary, but, as a book of science, ordinary readers will find it sufficiently advanced." —
UJticca Illoor;zizgg He-rald.
D. APPLETON  & CO., Publishers, 549 & 55i Broadway, N. Y.




Otinions of /he Press on the "I nternalional Scienltifc Series."
VII.
The Conservation of Energy.
By BALFOUR STEWART, LL. D., F. R. S.
Witk an Ayendzix treatzing of the Vital and AMental A51lications of the Doctrine.
I vol., I2mo.  Cloth.  Price, $I.50.
"The author has succeeded in presenting the facts in a clear and satisfactory manner,
using simple language and copious illustration in the presentation of facts and principles, confining himself, however, to the physical aspect of the subject. In the Appendix the operation of the principles in the spheres of life and mind is supplied by
the essays of Professors Le Conte and Bain."-Ohio Ezrmer.
" Prof. Stewart is one of the best known teachers in Owens College in Manchester.
" The volume of THE INTERNATIONAL SCIENTIFIC SERIES now before us is an excellent illustration of the true method of teaching, and will well compare with Prof.
Tyndall's -charming little bool in the same series on' Forms of Water," with illustrations enough to make clear, -but not to conceal his thoughts, in a style simple and
brief."-Chzristzia  Register, Boston.
" The writer has wonderful ability to compress much information into a few words.
It is a rich treat to read such a book as this, when there is so much beauty and force
combined with such simplicity. —Easternz Press.
VIII.
Animal Locomotion;
Or, WALKING, SWIMMING, AND FLYING.
With a Dissertation onz A'rtonauztics.
By J. BELL PETTIGREW, M. D., F. R. S., F, R. S. E.,
F. R. C. P. E.
I vol., I2mo......    Price, $I.75.
"This work is more than a contribution to the stock of entertaining knowledge,
though, if it only pleased, that would be sufficient excuse for its publication. But Dr.
Pettigrew has given his time to these investigations with the ultimate purpose of solving the difficult problem of Aeronautics. To this he devotes the last fifty pages of his
book. Dr. Pettigrew is confident that man will yet conquer the domain of the air." —
N. Y. Yozrnal of Commrzerce.
"Most persons claim to know how to walk, but few could explain the mechanical
principles involved in this most ordinary transaction, and will be surprised that the
movements of bipeds and quadrupeds, the darting and rushing motion of fish, and the
erratic flight of the denizens of the air, are not only anologous, but canr be reduced to
similar formula. The work is profusely illustrated, and, without reference to the theory
it is designed to expound, will be regarded as a valuable addition to natural history."
— Onaha ReluZblic.
D. APPLETON  & CO., PUBLISHERS, 549 & 551 Broadway, N. Y.




Opfinionzs of the Press on the  C Internaionazl: Scienti.ftc Series."
IX.
Responsibility in Mental Disease.
By HENRY MAUDSLEY, M. D.,
Fellow of the Royal College of Physicians; Professor of Medical Jurisprudence
in University College, London.
I vol., I2mo.  Cloth...  Price, $I.50.
"Havirfg lectured in a medical college on Mental Disease, this book has been a
feast to us. It handles a great subject in a masterly manner, and, in our judgment, the
positions taken by the author are correct and well sustained."-Pastor aand Peoie.
" The author is at home in his subject, and presents his views in an almost singularly clear and satisfactory manner.... The volume is a valuable contribution to one
of the most difficult, and at the same time one of the most important subjects of investigation at the present day." —N1. Y. Observer.
" it is a work profound and searching, and abounds in wisdom."-Piitsburg Conzncerczal.
" Handles the important topic with masterly power, and its suggestions are practical and of great value."-Providence Press.
X.
The Science of Law.
By SHELDON AMOS, M.A.,
Professor of Jurisprudence in University College, London; author of "A Systematic
View of the Science of Jurisprudence," " An English Code, its Difficulties
and the Modes of overcoming them," etc., etc.
I vol., I21mo.  Cloth.                 Price, $I.75.
"'The valuable series of'International Scientific' works, prepared by eminent specialists, with the intention of popularizing information in their several branches of
knowledge, has received a good accession in this compact and thoughtful volume.  It
is a difficult task to give the outlines of a complete theory of law in a portable volume,
which he who runs may read, and probably Professor Amos himself would be the last
to claim that he has perfectly succeeded in doing this. But he has certainly done much
to clear the science of law froin the technical obscurities which darken it to minds which
have had no legal training, and to make clear to his'lay' readers in how true and high a
sense it can assert its right to be considered a science, and not a mere practice."-The
Christianz Register.
"The works of Bentham and Austin are abstruse and philosophical, and Maine's
require hard study and a certain amount of special training. The writers also pursue
different lines of investigation, and can only be regarded as comprehensive in the departments they confined themselves to. It was left to Amos to gather up the result
and present the science in its fullness. The unquestionable merits of this, his lastbook,
are, that it contains a complete treatment of a subject which has hitherto been handled
by specialists, and it opens up that subject to e\ery inquti-ing mind.... To do justice
to' The Science of Law' would require a longer review than wee have space for. We
have read no more interesting and instructive book for some time. Its themes concern
every one who renders obedience to laws, and who would have those laws the best
possible. The tide of legal reform which set in fifty years ago has to sweep yet higher
if the flaws in our jurisprudence are to be removed. The process of change cannot be
better guided than by a well-informed public mind, and Prof. Amos has done great
service in materially helping to promote this end." —B2ffanlo Courier.
D. APPLETON  & CO., PUBLISHERS, 549 & 55i Broadway, N. Y~




Oj5inions of the Press on lie " International Scientific Series."
XI.
Animal Mechanism,
A  Treatise on Terrestrial and Abrial Locomnotion.
By E. J. MAREY,
Professor at the College of France, and Member of the Academy of Medicine.
With 117 Illustrations, drawn and engraved under the direction of the author.
I vol., I2mo. Cloth.                Price, $I-75
"We hope that, in' the short glance which we have taken of some of the most important points discussed in the wor-k before us, we have succeeded in interesting our
readers sufficiently in its contents to make them curious to learn more of its subjectmatter. We cordially recommend it to their attention.
" The author of the present work, it is well known, stands at the head of those
physiologists who have investigated the mechanism of animal dynamics-indeed, we
may almost say that he has made the subject his own. By the originality of his conceptions, the ingenuity of his constructions, the skill of his analysis, and the perseverance of his investigations, he has surpassed all others in the power of unveiling the
complex and intricate movements of animated beings."-Pnollzar Science lolnthly.
XII.
History of the Conflict between
Religion and Science.
By JOHN WILLIAM DRAPER, M. D., LL. D.,
Author of " The Intellectual Development of Europe."
I vol., I2mo.                                          Price, $1.75.
"Tllis little' History' would have been a valuable contribution to literature at any.ime, and is, in fact, an admirable text-book upon a subject that is at present engrossing the attention of a large number of the most serious-minded people, and it is no
small compliment to the sagacity of its distinguished author that he has so well gauged
the requirements of the times, and so adequately met them by the preparation of this
volume. It remains to be added that, while the writer has flinched fi-om no responsibility in his statements, and has written with entire fidelity to the demands of truth
and justice, there is not a word in his book that call give offense to candid and fairmil ded readers."-1V. Y. Evecnin~g Post.
"The key-note to this volume is found in the antagonism between the progressive
tendencies of the human mind and the pretensions of ecclesiastical aulthority, as developed in the history of modern science. No previous writer has treated the subject
from this point of view, and the present monograph will be found to possess no less
originality of conception than vigor of reasoning and wealth of erudition.... The
method of Dr. Draper, in his treatment of the various questions that come up for discussion, is marked by singular impartiality as well as consummate ability. Throughout his wol-k he maintains the positionl of at] historian, not of an advocate. His tone is
tranquil and serene, as becomes the search after truth, with no trace of the impassioned
ardor of controversy. He endeavors so far to identify himself with the contending
parties as to gain a clear comprehension of their motives, but, at the same time, he
submits their actions to the tests of a cool and impartial examination.'"-N. Y. Ti-rboune.
D. APPLETON  & CO., PUBLISHERS, 549 & 55i Broadway, N. Y.




RECENT PUBLICATIONS.
THE NATIVE RACES OF THIE PACIFIC STATES.
By HERBERT H. BANCROFT.  To be completed in 5 vols.  Vol. I. now
ready. Containing Wild Tribes: their Manners and Customs.
I vol., 8vo. Cloth, $6; sheep, $7.
"We can only say that if the remaining volumes are executed in the same spirit ol
candid and careful investigation, the same untiring industry, and intelligent good sense,
which mark the. volume before us, Mr. Bancroft's' Native Races of the Pacific States
will form, as regards aboriginal America, an encyclopedia of knowledge not only un
equaled but unapproached.  A literary enterprise more deserving of a generous sym
pathy and support has never been undertaken on this side of the Atlantic."-F'RANCIS
PARKMAN, in the North A merican Review.
" The industry, sound judgment, and the excellent literary style displayed in tlis
work, cannot be too highly praised."-Boston'ost.
A BRIEF HISTORlY OF CULTUREE.
By JOHN S. HITTELL.  I vol., I2mo.  Price, $I.50o.
" He writes in a popular style for popular use. He takes ground which has never
been fully occupied before, although the general subject has been treated more or less
distinctly by several writers.... Mr. Hittell's method is compact, embracing a wide
field in a few words, often presenting a mere hint, when a fuller treatment is craved by
the reader; but, although his book cannot be commended as a model of literary art, it
may be consulted to great advantage by every lover of free thought and novel suggestions."'-N. Y1. Tribune.
THE HISTORY OF THE CONFLICT BETWEEN R1ELIGION AND SCIENCE.
By JOHN W. DRAPER, M. D., author of "The  Intellectual Development of Europe." I vol., I2mo. Cloth. Price, $1.75.
"The conflict of which he treats has been a mighty tragedy of humanity that has
dragged nations into its vortex and involved the fate of empires. The work, though
small, is full of instruction regarding the rise of the great ideas of science and philosophy; and he describes in an impressive manner and with dramatic effect the way religious authority has employed the secular power to obstruct the progress of knowledge
and crush out the spirit of investigation. While there is not in his book a word of disrespect for things sacred, he writes with a directness of speech, and a vividness of characterization and an unflinching fidelity to the facts, which show him to be in thorough
earnest with his work. The' History of the Conflict between Religion and Science'
is a fitting sequel to the'History of the Intellectual Development of Europe,' and will
add to its author's already high reputation as a philosophic historian." —N. Y. Tribune.
THEOLOGY IN THE ENGLISH POETS.
COWPER, COLERIDGE, WORDSWORTH, and BURNS. By
Rev. STOPEORD BitooKE.  I vol., I2mo.  Price, $2.
"Apart from its literary merits, the book may be said to possess an independent
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lightened views of theology." —London A thenceamz.
BLOOCMElR'S CO01VIiERCIAL CRYPTOGRAPH.
A Telegraph Code and Double Index-Holocryptic Cipher. By J. G.
BLOOMER. I vol., 8vo. Price, $5.
By the use of this work, business communications of whatever nature may be te'o
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RECENT PUBLICATIONS.-SCIENTIFIC.
TH:E PRINCIPLES OF XIENTAL PHYSIOLOGY. With their Applications to the Training and Discipline of the Mind, and the Study of its
Morbid Conditions.  By W. B. CARPENTER, F. R. S., etc.  Illustrated.  I2mo.
737 pages. Price, $3.00.
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it has heretofore stood."-St. Louis De)eocmat.
" Let us add that nothing we have said, or in any limited space could say, would give an adequate conception of the valuable and curious collection of facts bearing on morbid mental conditions, the learned
physiological exposition, and the treasure-house of useful hints for mental training, which make this large
and yet very anmusing, as well as instructive book, an encyclopsedia of well-classified and often very
startling psychological experiences."-Lonldon Spectator.
THE EXPANSE OF HEAV[Ei N. A Series of Essays on the Wonders of
the Firmament. By R. A. PROCTOR, B. A.
"A very charming work; cannot fail to lift the reader's mind up' through Nature's worlk to Nature's
God.' "-London Standard.
" Prof. R. A. Proctor is one of the very few rhetorical scientists who have the art of making science
popular without making it or themselves contemptible. It will be hard to find anywhere else so much
skill in effective expression, combined with so much genuine astronomical learning, as is to be seen in his
new volume."'-C'ristian Union.
PHYSIOLOGY FOiR PRACTICAL USE. By various Writers. Edited
by JAMES HINTON.  With 50 Illustrations.  I vol., I2mo.  Price, $2.25.
"This book is one of rare value, and will prove useful to a large class in the community. Its chief
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formulas of medicine, and the style in which the information is given is so entirely devoid of the mystification
of technical or scientific terms that the most simple can easily comprehend it."-Bostosn Gazette.
" Of all the works upon health of a popular character which we have met with for some time, and we
are glad to think that this most important branch of knowledge is becoming more enlarged every day,
the work before us appears to be the simplest, the soundest, and the best."-C/iecago Inzter-oceasn.
THE GREAT ICE AGE, and its Relations to the Antiquity of
Man. By JAMIES GEIKIE, F. R. S. E. With Maps, Charts, and numerous Illustrations. I vol., thick I2mo. Price, $2.50.
"The Great Ice Age' is a work of extraordinary interest and value. The subject is peculiarly
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unscientific minds alike." —Boston, Gazette.
" Every step in the process is traced with admirable perspicuity and fullness by Mr. Geilie." —Lons
don Saturday lfeviese.
"' The Great Ice Age,' by James Geilkie, is a book that unites the popular and abstruse elements of
scientific research to a remarkable degree. The author recounts a story that is more romantic than nine
novels out of ten, and we have read the book from first to last with unflagging interest." —Bostonz Con2sme,.
cial Bulletin?.
ADDRESS DELIVERED BEFORE THE 3BRITISH ASSOCIATION, assembled at Belfast. By JOHN TYNDALL, F. R. S., President. Revised, with additions, by the author, since  the delivery.   I2mo.  I20 pages.
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This edition of this now famous address is the only one authorized by the author, and contains additions and corrections not in the newspaper reports.
THE PHYSIOLOG-Y OF DAN. Designed to represent the Existing State
of Physiological Science as applied to the Functions of the Human Body. By
AUSTIN FLINT, Jr., M. D.  Complete in Five Volumes, octavo, of about 500
pages each, with  o05 Illustrations.  Cloth, $22.00; sheep, $27.00.  Each volume sold separately.  Price, cloth,  4. 50; sheep, $5.50.  The fifth and last
volume has just been issued.
The above is by far the most complete work on human physiology in the English language. It treats
of the functions of the human body from a practical point of view, and is enriched by many original experiments and observations by the author. Considerable space is given to physiological anatomy, particularly the structure of glandular organs, the digestive system, nervous system, blood-vessels, organs of
special sense, and organs of generation. It not only considers the various functions of the body, from an
experimental stand-point, but is peculiarly rich in citations of the literature of physiology. It is therefore
invaluable as a worlk of reference for those who wish to study the subject of physiology exhaustively. As
a complete treatise on a subject of such interest, it should be in the libraries of literary and scientific men,
Rs well as in the hands of practitioners and students of medicine. Illustrations are introduced wherever
they are necessary for the elucidation of the text.
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A  New  Magazine for Students and Cultivated Readers.
THE
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CONDUCTED BY
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THE growing importance of scientific knowledge to all classes of the
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