Full text of "Introduction to zoology; a guide to the study of animals, for the use of secondary schools;"

See other formats

fit

i
K&flUUtMHWl

«i

MARINE BIOLOGICAL LABORATORY,

Received

*** No book or pamphlet is to be removed from the Lab-
oratory without the permission of the Trustees.

ru
m

a
a

o
m
a

f ' :

INTRODUCTION TO ZOOLOGY

INTRODUCTION TO ZOOLOGY^/

A GUIDE TO THE STUDY OF ANIMALS

FOR THE

USE OF SECONDARY SCHOOLS

CHARLES BENEDICT DAVENPORT, PH.D.

ASSISTANT PROFESSOR OF ZOOLOGY IN THE UNIVERSITY OF CHICAGO

DIRECTOR OF THE BIOLOGICAL LABORATORY OF THE BROOKLYN

INSTITUTE OF ARTS AND SCIENCES, LOCATED AT COLD

SPRING HARBOR, LONG ISLAND

AND

GERTRUDE CROTTY DAVENPORT, B.S.

FORMERLY INSTRUCTOR IN ZOOLOGY AT THE UNIVERSITY OF KANSAS

WITH THREE HUNDRED AND ELEVEN ILLUSTRATIONS

^® ^

— LIBRA ao

gork

THE MACMILLAN COMPANY, -vA

LONDON: MACMILLAN & CO., LTD.
1900

Nortoooti

J. S. Cushing & Co. — Berwick & Smith
Norwood Mass. U.S.A.

PREFACE

THE general plan of this text-book is at the same time
both old and new. Old, because it attempts to restore the
old-time instruction in Natural History ; new, because
"Natural History" is not to-day what it was a genera-
tion ago. The treatment will seem new also in contrast
with modern text-books of zoology, since they are devoted
primarily to comparative anatomy, a field upon which we
lay little stress.

This departure is the outcome of a conviction that the
needs of the secondary student are not best met by a
course in comparative anatomy. That conviction is not
altered by the circumstance that anatomy is fundamental
for advanced work in zoology and physiology, for only a
sixth of the secondary students go to college, and proba-
bly less than four per cent of them continue their zoologi-
cal work there. The vast majority of secondary students,
then, are not to be zoologists, but rather men of affairs.
What the ordinary citizen needs is an acquaintance with
the common animals that may be the companions of his
country walks, and that may even stray into Wall Street,
Dearborn Street, or Commonwealth Avenue. He wants
to know where else over the world the common animals
of his State are to be found and, as a legislator or as a
taxpayer, he wants to know how animals affect man. It
is more important for him to know these matters than to
know the location of the pedal ganglion of the snail, or

vi PREFACE

to be able to recite the various ingenious hypotheses
of the ancestry of echinoderms. Our conviction is, we
feel sure, the common conviction of college teachers of
zoology, who have often occasion to deplore the ignorance
that their students show about common animals. It is
the conviction of many other thoughtful men also who
have recognized that an interest in nature is a powerful
agent in making men more moral, more capable of appre-
ciating the world they live in, and of finding satisfaction
in living.

The aim of the book is indicated by its title. It is not
a treatise on the modern science of zoology. It is a guide
to the study of animals, which it is hoped may introduce
many students to the sciences of comparative anatomy,
comparative embryology, cytology, general physiology,
variation and inheritance, and the others that are grouped
under "zoology." This book is like a " Synoptic Room '
in the vestibule of a vast museum, containing the most
essential things for those who can go in but a little way,
but also fundamental for those who can penetrate farther.

The illustrations of this book have received especial at-
tention. An attempt has been made to give a lifelike figure
of a representative of almost every family mentioned in the
text. For courteous permission to reproduce the copied
figures we are deeply indebted to many publishers and
authors. We have to thank the authorities of the Field
Columbian Museum for original photographs, Figs. 301,
302, and 305. Mr. H. W. Menke, of the same institution,
kindly gave us permission to use his interesting photo-
graphs of live rattlesnakes, Figs. 261, 262. To Mr. V. H.
Lowe, Entomologist of the New York State Agricultural
Station at Geneva, N.Y., we are indebted for the photo-

PREFACE Vll

graphs marked V. H. L. ; these are published by permis-
sion of the Director of the Station. The majority of the
original photographs, designated by the initials W.H.C.P.,
were made by Mr. William H. C. Pynchon, Instructor in
Biology at Trinity College, Hartford. All of these, ex-
cepting Figs. 183, 184, 188, and 203, are photographs of
animals occurring around the Biological Laboratory at
Cold Spring Harbor, Long Island. They have thus a cer-
tain scientific value as indicating the fauna of that region.
As many of these figures are from living animals, probably
never before photographed in their natural attitudes, their
publication may be considered as something of a contribu-
tion to science. Of the other photographs, Figs. 31 a, 122,
276, 281, and 288, marked D. and S., were contributed by
Professor N. F. Davis of Bucknell University, Lewisburg,
Penn., and Mr. Ernest A. Sterling of the same institu-
tion; and Figs. 127, 251, and 259 were contributed by
Mr. E. R. Downing, graduate student at the University
of Chicago. The figures of birds by Louis Agassiz
Fuertes have been reproduced from " Citizen Bird," by
Mrs. Wright and Dr. Coues, published by the Macmillan
Company. Figures of the types used in the outline of
laboratory work have been purposely avoided.

Finally, the authors have to thank several secondary
teachers who have kindly made suggestions and helpful
criticisms on the outline of laboratory work and the main
text. AVe solicit a continuance of these favors to the end
that this book may become as perfectly adapted as pos-
sible to the needs of secondary instruction in zoology.

C. B. DAVENPORT.

GERTRUDE C. DAVENPORT.

CHICAGO, May 19, 1900.

CONTENTS

CHAPTER I

PAGE

THE GRASSHOPPER AND ITS ALLIES . . 1

Key to the four principal families of Acrididre . . 2

APPENDIX : Key to the principal families of the Orthoptera . 14

CHAPTER II

THE BUTTERFLY AND ITS ALLIES ... 15

APPENDICES : Key to the principal families of Lepidoptera 41

Key to the principal families of Hymenoptera ... 42

CHAPTER III

THE BEETLE AND ITS ALLIES ...... 44

APPENDIX : Key to the principal families of the Coleoptera . 58

CHAPTER IV

THE FLY AND ITS ALLIES ...... 62

APPENDIX : Key to the suborders of Diptera .... 02

CHAPTER V

LlTHOBIUS AND ITS ALLIES .... 74

APPENDIX : Key to the principal families of the Myriapoda . 78

Key to the commoner species of the genus Lithobius . . 79

CHAPTER VI

THE SPIDER AND ITS ALLIES ... 80

APPENDIX : Key to the seven suborders of the Araueina . .95

29390

CONTENTS

CHAPTER VII

PAGE

THE CRAYFISH AND ITS ALLIES 97

APPENDICES : Key to the six chief orders of Malacostraca » 122

Key to the principal families of Podopthalinata . . . 122

CHAPTER VIII

THE DAPHNIA AND ITS ALLIES 125

APPENDICES : Key to the five orders of Entomostraca . . 131

Key to the principal families of Cladocera .... 131

CHAPTER IX

THE EARTHWORM AND ITS ALLIES . 133

APPENDICES : Key to the principal species of Earthworms of the

United States 143

Key to the principal families of aquatic OligocliEeta . . 144

CHAPTER X

NEREIS AND ITS ALLIES 145

APPENDIX : Key to the more important families of Polychseta . 159

CHAPTER XI

THE SLUG AND ITS ALLIES 160

Key to the three orders of Gastropoda 160

Key to the principal families of American Pulmonata . . 161
APPENDIX : Key to the principal families of marine shelled
Gastropods of the Atlantic coast of the United States . .174

CHAPTER XII

THE FRESH-WATER CLAM AND ITS ALLIES 178

APPENDIX: Key to the principal families of marine Lamelli-
branchiata of the east coast of the United States . . .188

CHAPTER XIII

THE STARFISH AND ITS ALLIES . 192

APPENDIX : Key to the principal classes of Echinodermata . 203

CONTENTS xi

CHAPTER XIV

PAGE

HYDRA AND ITS ALLIES ......... 205

APPENDICES : Key to the principal subdivisions of the Cnidaria 220

Key to the families of the Hydromedusae .... 220

CHAPTER XV

THE PARAMECIUM AND ITS ALLIES 222

APPENDICES : Key to the four classes of Protozoa . . . 229

Key to the subclasses and orders of Infusoria . . . 229

CHAPTER XVI

THE SMELT AND ITS ALLIES ........ 230

APPENDICES : Key to the principal orders of fishes . . . 252

Key to the six suborders of Teleostei 252

CHAPTER XVII

THE NEWT AND ITS ALLIES ........ 254

APPENDICES : Key to the orders of Amphibia .... 266

Key to the families of Urodela 266

CHAPTER XVIII

THE LIZARD AND ITS ALLIES 268

APPENDIX : Key to the four orders of Reptiles .... 280

CHAPTER XIX

THE ENGLISH SPARROW AND ITS ALLIES 281

APPENDICES : Key to the orders of Birds 314

Key to the families of Passeres of northern United States . 315

CHAPTER XX

THE MOUSE AND ITS ALLIES 318

APPENDIX : Key to the orders of Mammalia .... 331

CHAPTER XXI

THE DEVELOPMENT OF THE FROG'S EGG . . . 332

xil CONTENTS

APPENDIX I

PAGE

OUTLINE OF LABORATORY WORK IN ZOOLOGY .... 337

INTRODUCTION .......... 337

EXERCISES 342

I. Grasshopper 342

II. Butterfly . . 343

III. Beetle 344

IV. Housefly or Bluebottle Fly 345

V. Lithobius 347

VI. Spider 348

VII. Crayfish 349

VIII. Daphnia 351

IX. Earthworm . . 352

X. Nereis 353

XI. Slug 354

XII. Fresh-water Clam 356

XIII. Starfish 357

XIV. Hydra 358

XV. Paramecium . . . . . . . . 359

XVI. Smelt 361

XVII. Newt 362

XVIII. Lizard 363

XIX. " English " Sparrow 364

XX. Mouse 365

XXI. Development of the frog's egg 366

METHODS OF EXAMINATION 367

APPENDIX II

A LIST ov BOOKS DEALING CHIEFLY WITH THE ECOLOGICAL AND

SYSTEMATIC ZOOLOGY OF AMERICAN ANIMALS .... 369

APPENDIX III

SYNOPSIS OF THE ANIMAL KINGDOM ...... 383

GLOSSARY . 391

I^NDEX .,»,».••>••> out

INTEODUCTION TO ZOOLOGY

INTRODUCTION TO ZOOLOGY

CHAPTER I

THE GRASSHOPPER AND ITS ALLIES

Relationships. — The grasshopper belongs to an order
of insects called Orthoptera.1 In this group of insects2
there is an incomplete metamorphosis during development,
so that the general form of the young resembles that of
the adult. The anterior and posterior pairs of wings are
unequal. The jaws are adapted for biting.

The name " grasshopper ' is applied to two families of
insects; namely, the Acridida^8 and the Loeustidse. Both
of these families have long hind legs, used in jumping, an
elongated body flattened from side to side, and a wedge-
shaped head directed downward ; they differ in the length
of the antennae.

Habits.- -The Acrididae, or short-horned grasshoppers,
are found in both hemispheres. They live, for the most
part, on the ground in very diverse conditions, such as in
low, damp meadows or in dry uplands, arid deserts, and
rocky mountain sides. They are all herbivorous, and may

s, with straight (lying straight out) wings.

2 The principal families of Orthoptera may be distinguished by the
key in the Appendix to this Chapter, p. 14.

3 a.Kpi5i.ov, a small grasshopper of Dioscorides.

B 1

2 ZOOLOGY

feed upon almost any green part of plants. Some of tLu
species are gregarious (i.e. go in swarms) and may be
very destructive.1

Melanoplus 2 is the prevailing genus of North America
and covers nearly all of the continent. While in the
East certain species of the genus Melanoplus may become
destructive to vegetation, the injury done is not so great
as was formerly done by the Rocky Mountain locust. At
various times for some cause, probably drought, this locust
has migrated eastward from its mountain home in countless
millions and devastated our Western States as far as the
Mississippi River. In 1873 to 1877 the Rocky Mountain
locust was so destructive to vegetation in the trans-
Mississippi region that Congress appointed a commission
to investigate the species. In describing its effect the
commission reports : -

" Falling upon a cornfield, the insects convert in a few hours the
green and promising acres into a desolate stretch of bare, spindling

1 The following key will aid in determining the four principal Ameri-
can subfamilies of the Acrididse : — •

a\. Feet without a claw-pad. Pronotum covering all

the body. Fore wings lobe-like .... Tettigidce

(Tettix Shorthorns)

a*. Feet with a claw-pad ; antennse longer than an-
terior femora.
61. Prosternum without a spine.

GI. The plane of the vertex of the head meet-
ing the plane of the front of head at an
angle, the face looking down . . . Tryxalidce

(Angle-headed Shorthorns)

C2. The planes of the vertex and head round

over into each other .... CEdipodce

62- Prosternum with prominent spine . . . Mehtnoplidce

(Thorn-throated Shorthorns)

s, black ; oir\a, armor.

THE GRASSHOPPER AND ITS ALLIES 3

stalks and stubs. . . . Their flight may be likened to an immense
snow-storm, extending from the ground to a height at which our
visual organs perceive them only as minute, darting scintillations, ,
leaving the imagination to picture them indefinite distances bej^ond.
... In alighting, they circle in myriads about you, beating against
everything animate or inanimate ; driving into open doors and win-
dows; heaping about your feet and around your buildings, their jaws
constantly at work, biting and testing all things in seeking what they
can devour."

The locusts of the Old World are likewise frequently
very destructive. The species that lives in southern
Europe, North Africa, Asia Minor, Syria, Java, and Japan
is doubtless the locust of the Bible. The description
given by the prophet Joel is very vivid and accurate : -

" A day of darkness and of gloominess, a day of clouds and of thick
darkness, as the morning spread upon the mountains ; a great people
and a strong ; there hath not been ever the like, neither shall be any
more after it, even to the years of many generations. A fire devoureth
before them, and behind them a flame burneth : the land is as the
garden of Eden before them, and behind them a desolate wilder-
ness; yea, and nothing shall escape them. The appearance of them
is as the appearance of horses ; and as horsemen, so shall they run.
Like the noise of chariots on the tops of mountains shall they leap,
like the noise of a flame of fire that devoureth the stubble, as a strong
people set in battle array. Before their face the people shall be much
pained ; all faces shall gather blackness. They shall run like mighty
men ; they shall climb the wall like men of war ; and they shall march
every one on his ways, and they shall not break their ranks. . . . They
shall run to and fro in the city; they shall run upon the wall; they
shall climb up upon the houses; they shall enter in at the windows
like a thief."

General Development of the Grasshopper. - The common
red-legged grasshopper lays its eggs during the fall in
holes in the ground which the female drills by means of

4 ZOOLOGY

the horny plates at the tip of the abdomen. The eg
thirty to one hundred in number, are laid in a mass and
covered with a gelatinous secretion. In these holes, an
inch or so below the surface of the ground, the eggs pass
the winter and hatch out in early summer into young
grasshoppers, looking like adults except for their small
size and the absence of wings. As they grow larger they
moult several times, i.e. cast off their cuticular coverings.
After each moult the body is left soft and colorless, but
being freed of its hard, tight casement, it is in a condition
to grow rapidly. After each moult also the rudimentary
wings (wing-pads) become larger, and the relative sizes of
the parts of the body change. Just before the last moult
the pupa crawls up some vertical object, clutches it firmly
with the hind feet, and remains motionless in this position
for several hours. Then the cuticula splits along the
middle of the back, the head and body inside the cuticula
swell, the head emerges from the case, and gradually the
entire body works forward out of the old cuticula ; not
easily, indeed, but with violent contortions and pullings.
The legs and antennae are especially difficult to free ; they
can pass out of the joints of the old skin only because
they are soft and flabby ; but as soon as they become
exposed to the air their surface secretion hardens into a
firm covering. The wings are at first rolled up ; they
now expand broadly, dry, and then fold up in the way we
see them in the adult.

Allies of the Grasshopper. - The Gryllidae,1 or crickets
(Fig. 1), include cosmopolitan insects that have short,
cylindrical bodies and live chiefly in hidden places, such
as beneath stones or in holes Avhich they make in the

1 Name derived from sound made by crickets.

THE GRASSHOPPER AND ITS ALLIES

ground. Their eggs are laid loosely in these retreats.
They feed on plants and, if numerous, may be decidedly
injurious to vegetation. They make
a familiar chirping noise, the blended
sounds of which, as heard on a sum-
mer evening, rise and fall in a distinct
rhythm. The rate of chirp seems to be
entirely determined by temperature, so
that one may compute the temperature
by means of the formula

^-40

FIG. 1.— Gryllus,

— , , cricket. Nat. size.

Photo, by W. H.

in which T stands for temperature, and

N the number of chirps per minute. The mechanism by

which the chirp is produced is as follows : Near the mid-
dle of each of the upper wings of
the male cricket is a vein so modi-
fied as to form a sort of file, and
near the margin of the wing is a
thickened scraper. When the up-
per wings are brought in contact
above the body, and the scraper of
one is rubbed across the file of the
other, the wings are set in vibration,
producing the call.

An aberrant form of Gryllidee is
the mole cricket (Fig. 2), whose

FIG. 2.--Grii!iuta?pa bore- f°re feet have become much modi-

alis, mole cricket. Nat. ne(j f()r burrowing,
size. Photo, by W. H.

C p 1 he Locustidae,1 or long-horned

1 From the Latin name for the locust and grasshopper, as well as the
lobster.

ZOOLOGY

grasshoppers and katydids, are close allies of the short-
horned grasshoppers already defined. Next to the numer-

FIG. 3. — Orchelimum, meadow grasshopper. Nat. size. Photo.

by W. H. C. P.

ous meadow grasshoppers (Fig. 3) belonging to this group,
the katydids are the best known of its representatives. The
katydids have their whole body green, like the foliage they

FIG. 4. — Ceuthophilus, cricket-grasshopper. Two-thirds nat. size.

Photo, by W. H. C. P.

inhabit. The wings are large; and when the upper wings
are rubbed together, they vibrate, and cause the familiar

THE GRASSHOPPER AND ITS ALLIES 7

note. Other members of this group are the cricket-grass-
hoppers (Fig. 4), wingless forms, of a brown color and
arched profile, which live under stones and rubbish, and
also the cave " crickets," which are
colorless and blind.

The Phasmidae^or walking-sticks
and leaf-insects, display, to a mar-
vellous degree, a protective resem-
blance to the twigs and leaves among
which they live. The most remark-
able forms live in the tropics. They
have large wings, which strikingly
resemble, in form, color, and vena-
tion, either living or dry leaves.
Upon those species which resemble
dried leaves, blotches looking like
fungous patches are found. Even
the legs may be thin and expanded,
resembling foliage. In our country
only the twig-like, wingless forms,
or walking-sticks, occur. These in-
sects are furthermore protected by
changes in color, corresponding with
the seasonal color changes in twio-s;

o o

for the young walking-sticks, which

appear in the spring, are green like

the twigs, but in the autumn they

become gray or brown. Figure 5 shows our only common

northern species, Diapheromera femorata. It feeds on

leaves, especially those of the oak, and occasionally does

much damage to trees.

FIG. 5.— Diapheromera, walk-
ing-stick of northern U. S.
Nat. size. Copied from
Packard.

appearance, spectre.

ZOOLOGY

The Mantidae l are popularly called praying-mantis, on
account of the devotional attitude in which the greatly en-
larged front legs are held. Unlike other Orthoptera, they

FIG. (i. — Phasmomantis niroUim. Praying-mantis of southern U. S. Nat.

size. Copied from Packard.

are carnivorous. They hunt and devour other insects some-
times larger than themselves, and even prey upon each other.
\Yhile most of the species are tropical, one species, Phasmo-
mantis Carolina (Fig- 0), is abundant
in our Southern States, and another
occurs in the Missouri valley.

The Blattidae,2 or cockroaches, are
especially creatures of the tropics;
and those which live in colder cli-
mates frequent warm as well as dark
places. The two which are our
household pests have been imported
from Europe,- -both the small brown
" ( 'roton bug," which is found among
water-pipes in the kitchen, and the
large black species commonest in sugar-refineries, slaughter-
houses, and bakeshops. They are omnivorous, eating,

7. - • Wingless cock-
roach. Xat.size. Photo,
l.v AY. H. C. P.

seer, prophet.

2 blatta, roach of Pliny.

THE GRASSHOPPER AND ITS ALLIES 9

among other things, breadstuffs, clothing, book-bindings,
bedbugs, and other insects. We have also a number of
native cockroaches, which live chiefly in fields and woods,
under stones and logs. Some of these are wingless (Fig. 7).

The following groups are frequently excluded from the
Orthoptera, but show a certain relationship with them : -

The Forficulidae,1 or earwigs, are rare in the northern
United States, but commoner in the Gulf and Pacific States.
In general appearance they resemble rove-beetles, but differ
from them in having a pair of forceps at the posterior end
of the body. They hide, during the day, in the corollas of

v» * «

* T **f» r

/""~ <^n

c..

FIG. 8. — Two North American Odonata, belonging to the family Libelhilid:
About one-half nat. size. Photo, by V. H. L.

flowers, upon which they feed, and fly about at night. The
name earwig seems to have arisen from an unwarranted
belief that these insects penetrate into the ears of persons
when asleep. They were especially dreaded on account
of a fear that thev mio-ht thus penetrate into the brain.

V O A

The Odonata,2 or dragon-flies, have four membranous, net-
veined wings, of which the front pair are never larger than
the hind ones. Their large heads carry relatively enormous
eyes. Two groups of dragon-flies may be distinguished
according as the wings, at rest, are extended (Fig. 8) or

1 forfiwila, a small forceps.

" 65ovs, tooth, from the teeth of the mandibles.

ZOOLOGY

folded together over the back. Dragon-flies live on the
wing, hovering over water and preying upon other insects,

especially mosquitoes. The eggs develop
in the water into aquatic larvae which are
quite unlike the adult. Especially the
jaws are peculiar, being jointed and capa-
ble of sudden protrusion, in order to catch
the animals which serve as prey. These
larvee are easily reared over winter in an
aquarium, where not only their ferocious
habits, but also their peculiar method of
breathing by means of water taken in at
the anus, may be observed (Fig. 9).

The Ephemeridae,1 or May-flies. The
FIG. 9. - - JEschna, adult May-fly possesses finely veined fore

old larva, or pupa. . 1-1 ^ ^ , i , i

Nat. size. Photo, wings, winch are much larger than the
by w. H. C. P. hind wings. The mouth parts are rudi-

mentary and the abdomen terminates in
two or three filamentous appendages. As their systematic
name implies, they have a very ephemeral existence in
the imago state. The imago appears in swarms early in
the summer and lives but a fe\v hours, eating nothing
and depositing eggs upon or under stagnant water. The
larvse feed upon small aquatic plants and insects, breathe
by means of gills placed on the back, and live for nearly
a year, or even for two or three years, in the immature
stages. After many moultings the apparent adult emerges,
but, unlike other insects, undergoes an additional moult
before laying its eggs. As the insect is subjected to many
accidents in its long and defenceless life, each species is
preserved only by an enormous fecundity.

. a day, i.e. lasting but a day, short-lived.

THE GRASSHOPPER AND ITS ALLIES 11

White ants, or termites (Fig. 10), while not true ants,
live a very similar social or communal life. They differ
from ants in the venation of the net-veined
wing (when present). White ants are most
abundant in the tropics, where they build
great conical nests of sand cemented by
their saliva ; but they are found also in
temperate countries. The common eastern
white ant (Termes flavipes) ranges from

FIG. 10.— Termes

Massachusetts southward, and lives in /«?><><?*, white
wood or under stones. Three kinds or ' ant-" Nat-

size. Photo, by

castes of white ants occur in any com- w. H. c. P.
munity : (1) workers, with small, round
heads and concealed mandibles ; (2) soldiers, with large,
square heads, and long, powerful mandibles ; and (8) the
royal class of kings and queens, which have wings until
after the marriage flight. At a certain time in May the
males and females from the various colonies fly forth
to mate, and thus an interbreeding takes place between
colonies. Only a few of the pairs, however, find workers
to aid them in establishing a new colony. The queen,
after she is established in a new hive, merely produces
young, the abdomen becoming immensely swollen and
elongated to fifteen centimetres with the eofS's which are

O OO

about to be laid. In tropical countries the termites are
troublesome to man by injuring trees and devouring the
woodwork of houses.

The order Neuroptera includes certain insects which
differ from the Orthoptera in having larvje very unlike
the adult, and in having a resting pupal stage in which
the metamorphosis into the adult is completed. There are
four membranous, clear, net- veined wings, and the mouth

ZOOLOGY

parts are used for biting. The largest representative of
this group is the Horned Corydalis (Fig. 11), whose larva
lives in streams and is called the clobson. The adult
is found among fallen leaves or on tree
trunks.

The order Hemiptera includes certain
insects which resemble the Orthoptera in

FIG. 12. — Hygrotreclms, water-strider. Nat. size.
Photo, by W. H. C. P.

undergoing an incomplete metamorphosis;
i.e. in having larvie much like the adults
in form, and in having no (juiet pupal

stage. They differ
from the ( )rthoptera
in possessing mouth-
parts adapted to

FIG. 13. — Reduvius, the
assassin bug. Black.
Nat. size. Photo, by
W.H. C. P.

FIG. 11. - - Cory-
dalis, the dobson.
Two -thirds nat.
size. Photo, from
life by AV.H.C.P.

sucking.

The True Bugs (Heteroptera) in-
clude a vast number of generally
small insects with very varied habits.
Some of them swim through the
water and are known as water boat-
men ; others skip over the surface of
the water and are known as water-
striders (Fig. 1-). Others, like the

THE GRASSHOPPER AND ITS ALLIES

Squash Bug, are destructive to plants ; still others, like
the Reduviidse, kill injurious insects (Fig. 13).

F'G. 14. — Cicada septonrfccem, the seventeen year locnst.

Photo, by V. H. L.

Reduced.

FIG. 1<>. — Locanium, a scale insect.
Remains of females after production
FIG. 15. — Pupal case of cicada. Two- of yoiuii>' ; seen as swellings on the
thirds nat. size. Photo, by W. H. C. P. bark. Nat. size. Photo, by V.H.L,

ZOOLOGY

The Homoptera include insects of very diverse size and
form. The largest are the cicadas, or "locusts" (Fig. 14),
some of which have the remarkable habit of requiring
thirteen or seventeen years for their development. Con-
sequently these cicadas
appear only at intervals
of thirteen or seventeen
years. The young bury
themselves in the
ground and live by
sucking juices from the
roots of trees. Eventu-
ally they come to the
surface, leave their lar-
val skin (Fig. 15), and
FIG. 17. — Schizoneura, a woolly aphis, on flvqwav iq full o-rnwn
apple twig. Photo, by V. H. L.

cicadas. In the case of

our common species of cicada there is a brood every year.
Besides the cicadas the Homoptera include the little
leaf-hoppers and tree-hoppers, the very destructive scale-
bugs (Fig. 16), and the mealy-bugs, most of which attack
fruit trees and their fruits, and the plant-lice, or aphids
(Fig. IT).

APPENDIX TO CHAPTER I

KEY TO THE PRINCIPAL FAMILIES OF THE ORTHOPTEKA

a\. Legs similar, fitted for running ....
«2- First pair of legs differentiated for grasping ; pro-

thorax elongated

Blattidce
(Cockroaches)

Mantidce
(Praying-mantis)

APPENDIX TO CHAPTER I 15

«3. Legs similar, much elongated, and fitted for slow

walking . Phasmidce

(Walking-sticks)
«4. Hinder legs stouter or longer than middle pair.

61. Antennae shorter than body .... Acrididce

(Locusts and Short-horned Grasshoppers)

62. Antennae longer than body.

Ci. Tarsi 4-jointed Locustidce

(Katydids and Long-horned Grasshoppers)

c2. Tarsi 3-jointed Gryllidai

(Crickets)

CHAPTER II

THE BUTTERFLY AND ITS ALLIES

Systematic Position. — Butterflies belong to the insect
order Lepidoptera,1 characterized by the possession of a
long, coiled, sucking proboscis; large, membranous wings,
covered with colored scales; and a complete metamorphosis.
They occur over the whole globe, but become more numer-
ous in species in the tropics of South America and Africa.
The number of known species is about twenty-five
thousand.2

The Habits and Food of Butterflies. - The idea of a
butterfly should not be limited to the winged adult called
the imago, for strictly we may call a caterpillar a larval
butterfly, and a pupa an adolescent butterfly. Hut in its
different stages the habits and food of a butterfly change.
Caterpillars feed, for the most part, upon plants. A few -
such as the clothes-moth and certain enemies of scale in-
sects - -feed upon animal matter. Any single species of
caterpillar feeds upon the foliage of a restricted number of
kinds of plants. At one extreme we have forms which
starve unless they can reach their own particular food
plant; at the other extreme there are caterpillars which
can live upon the foliage of many kinds of plants, and
these are consequently called polyphagous. Certain fami-

1 \e-n-is. scale ; irrepbv, wing.

2 The principal families of Lepidoptera may be distinguished by the
key in the Appendix to this Chapter, p. 41.

THE BUTTERFLY AN 7) TT8 ALLIED 1<

lies of plants especially serve caterpillars as food. Thus of
the hundred species of New England butterflies, eight feed
upon oaks, eleven upon willows, thirteen upon the Rosacese,
and twenty-eight upon leguminous plants. It follows from
the restricted food of many caterpillars, that the range of
the species must often be determined by that of its food-
plant.

The feeding of the butterfly is mostly done in the larval
stage: the pupa can take no food. The imagos of many
species touch no food, but in other cases they take small
quantities of the nectar of flowers, the sap of plants, and
the juice of fruits.

The imagos fly in the daytime, especially in the sun-
shine. Certain species are characteristic of the roadside,
others of meadows, gardens, or woods, while still others are
found flying everywhere. Owing to its ordinarily short
life, the imago is usually found not far from the larval
food-plant, upon which it lays its eggs.

The Broods of Butterflies and their Polymorphism. —
Butterflies winter over in various stages, some in the ego;

O OiT5

stage, some as larvae, others as pup?e or as imagos. Some
kinds pass the winter in either of two stages. In whatever
stage they tarry, the life current runs very slow, and dur-
ing this season few changes take place. In the spring,
development goes on rapidly: the winter generation be-
comes mature and a summer generation is started. Fre-
quently there is more than one brood produced during the
summer, even in the Northern States. Farther south two
and even three summer broods are still commoner. Where
two or three broods occur they may be and usually are
quite dissimilar. This is very strikingly illustrated in the
case of the Zebra Swallow-tail, Iplii<-li<l<'x
c

18 ZOOLOGY

of the southeastern United States, which is multiple-
brooded. The early spring form (marcellus form) is the
smallest, and has the tail tipped with white; the summer
form (ajax) is the largest, and has the tail two-thirds
longer than the marcellus form. Other illustrations of
this seasonal difference are given by the imported Cabbage
Butterfly, the Gray-veined White and the Spring Azure.
This dissimilarity between the broods of different seasons
is known as seasonal dimorphism or polymorphism. The
cause of the difference between the different broods seems
to be the dissimilar climatic, especially thermic, condi-
tions under which they have developed. Mr. W. II.
Edwards in this country, and Weismann and others in
Europe, have shown that, when the summer form is kept
during development in a refrigerator, the butterfly has the
color of the winter form.

Protective Resemblance and Mimicry. — Every one who
has visited a natural history museum must have noticed
that the polar mammals are apt to be more or less white,
while those which live in tropical forests are dark. It is
easy to understand that these colors in their proper sur-
roundings make the animals which wear them hard to
see. This may be of advantage in enabling them to
escape the observation of their enemies, which are seeking
for them, or to avoid being seen by their prey as they ap-
proach. This general resemblance to their background is
seen even in some caterpillars, e.g. the tomato-worm, which
is colored so exactly like the leaf on which it feeds that it
is hard to find. Other caterpillars, belonging to the geo-
metrid moths, have the color of the twigs of the plant on
which they feed, and the resemblance is heightened by the
way they have of stiffening and standing out like a branch

THE BUTTERFLY AND ITS ALLIES

from the stem. The moths of the genus Catocala,1 which
fly by night, rest by day on the bark of trees, which they
so resemble as to be almost indistinguishable. Still more

striking is the resemblance which we find between some
adult butterflies and dry leaves as seen, for example, in Kal-
lima, a butterfly of the East Indies.2 The resemblance of
the butterfly to the leaf extends even to details, for the
clear patches on the wing resemble holes, while little cir-

FIG. 18. — Catoccdu ilia, the underwing. Upper wings, bark color; lower
wings, black with orange bauds. Photo, by C. Billiard.

cular markings resemble the patches made by particular
kinds of fungi. This resemblance of an organism to in-
animate objects in its environment is known as protective
resemblance.

There are certain species of butterflies which appear to
be let alone by birds, owing to their disagreeable odor or
acrid taste. Examples of such are the Heliconidae, char-
acteristic of tropical South America, and the Danaidre, to
which family our " Monarch " belongs. Closely resembling

1 Fig. 18. 2 Fig. 19.

ZOOLOGY

the Monarch in this country is the "Viceroy," Limenitis
arcliippm. This resemblance of the edible Viceroy to
the inedible, acrid Monarch, it is believed, is sufficient to

FIG. 19. — A, Kallima, the leaf-butterfly of the East Indies, Hying'; «, at rest.
£, Siderone, another leaf-butterfly, flying; b, at rest.

deceive even the birds, and thus the Viceroy gains con-
siderable immunity from attack. This resemblance of an
edible to an immune species is known as mimicry. The
origin of protective resemblance and mimicry are both

THE BUTTERFLY AND ITS ALLIES 21

explained by the theory of Natural Selection or Darwin-
ism. Since either of them is of great utility to the
organism, their possession, even to a slight degree, how-
ever accidentally gained, will give their possessor an ad-
vantage over its neighbors in the Struggle for Existence.
Consequently it will be more apt to survive and transmit
its peculiarity to its offspring. By this means an adapted
race will arise and crowd out the unadapted.

Types of the Butterflies. — The group Papilionidse in-
cludes the butterflies which fly by day. An account of
the most important follows. The Papilios (Swallow-tails)
are our largest butterflies. Here belong the yellow Tiger
Swallow-tail (turnus), with black stripes, which is found
over nearly the whole United States; and the black Swallow-
tail (asterias), whose wings are crossed by rows of yellow
spots, and whose hind wing bears an orange, black-eyed
spot. Its larvae feed on wild or cultivated umbelliferous
plants, especially parsnip leaves.

The Cabbage-butterflies (Pieris) have white or yellow-
ish wings, tipped and spotted with black, or sometimes with
orange. They hover over damp spots in roads or fly
through garden patches. The larvae are very destructive
and feed on cabbage and other cruciferous plants.

To the Nymphs belong the Angle-wings whose fore
wings are notched on their outer edge. Here belongs the
butterfly which we sometimes see on warm days in winter
or early spring — the Mourning-cloak. This has pur-
plish brown wings with a broad yellow border, and a
row of pale blue spots. The Graptas belong here, too;
they may be told by the silver spot on the hind wing.
In the Admirals the wings are less deeply notched.
The red Admiral is purplish black above, with an

22 ZOOLOGY

orange band and white spots running obliquely across
the upper side of the fore wing. It occurs in England
as well as in the United States. Here belongs also the
Viceroy, which is not closely related, but is quite similar
to the Monarch because the former mimics the latter.
They are both of a tawny orange color, with a white-
spotted black border on the outer wing margin. The
Monarch is the larger, and like the birds has the habit
of migrating southward in the fall and returning in the
spring. The Fritillaries (Argynnis 1) include some large
butterflies, having numerous round and triangular silvery
spots on the under side of the hind wing.

To the Lycaenas2 belong the Blues, or Spring Azures,
including small satin or steel-blue species which exhibit
marked seasonable polymorphism ; the Coppers, orange-
red, or brown species; and the Hairstreaks, or Theclas,3
which are small, brown butterflies, usually with two tails
to the hind wing.

Types of the Moths. - These include all Lepidoptera,
excepting the family of Papilionidse. Seven families are
of rather large size (Macrolepidoptera) ; the remaining four
are of small size (Microlepidoptera).

The Sphingidae,4 or Hawk-moths, fly swiftly and power-
fully, and as they hover over flowers at du,:,k can hardly be
distinguished from humming-birds. The larva) have a
caudal horn or tubercle. The commonest of these are the
tomato or potato " worm," green in color and banded.
There are about one hundred species of the Sphingidse in

1 'Apyvwis, the "silvery," a poetic name of Venus.

2 Aikaii/a, a poetic name of Venus.

3 A Greek feminine name.

4 From 20t7£, or sphinx, a fabled monster. The larva of this moth
• assumes an attitude like the sphinx.

THE BUTTERFLY AND ITS ALLIES

the United States. The Twin-spotted Sphinx (Fig. 20), so-
called from the black spots of the hind wing, is destructive

FIG. 20. — Smerinthus f/eminatus, the Twin-spotted Sphinx. Nat. size.

Photo, by W. H. C. P.

to fruit and shade trees. The Pandorus Sphinx (Fig. 21)
is of a beautiful olive color ; its larva feeds on vines.

FIG. 21. — Philampelus pandorus, the Pandorus Sphinx. Nat. size. Photo.

hy W. H. C. P.

The Xylotropidae l are chiefly medium to small, clear-
winged species which fly at dusk or in daylight. Their

, wood ; r/)e0w, to feed ; because the larvae feed on wood.

ZOOLOGY

larvre live in stems of squash, cucumber, etc., and bore

into shrubs and trees (Fig. 22).

The Arctiidae,1 or Tiger-moths, are for the most part con-

spicuously striped or spotted. The larvae are very hairy.

The best known is the furry, brick-red and black Isabella

caterpillar, which can be seen
during October in New Eng-
land, hurrying nervously in
search of winter quarters.

The Bombycidae2 include,
as a rule, large and thick-
bodied moths. Here belong

the silkworm moths - - the
only moths of use to man.
( )f these, Bombyx mart 3 is
the most generally employed
in the manufacture of silk. It
originally came from China,
feeds on the leaves of the
white mulberry, and is reared

Fia.22.-Larvaof oneof theSesiidse Cnie% in China> JaPan> Itilly>

and France. The method of
culture is as follows : The
eggs ("grains") are laid in the autumn, kept over winter
in a dry, airy, and cool place, and hatched when the mul-
berry begins to send out its leaves. On these leaves
the larvie are put to feed, and after a month they begin
to spin. For commercial purposes the larvae are induced

1 From ap/cros, bear.

2 Bombyx-like. Aristotle called the rustling silk /36/x/3os ; hence the
name Bombyx for the silkworm.

3 morus, a mulberry tree.

.u in stem. Nat. size. Photo,

THE BUTTERFLY AND ITS ALLIES

to spin the cocoons on prepared twigs or straw. A few
days after the cocoon is completed its inhabitant is killed

FIG. 23. — Citheroma rcf/al!x, the Regal moth. Olive and red wings, yellow
spots. Nat. size. Photo, hy W. H. C. P.

in-hot water. The cocoon is made of a continuous thread
about three thousand metres long, of which, however, only

FIG. 21. — Larva of Citheronia regalis. Head to left. One-half nat. size.

Photo, by W. H. C. P.

about six hundred metres make good silk. This long
thread has to be unravelled. The outer end is loosened

ZOOLOGY

by soaking the cocoon in hot water ; then several of these
ends are brought together and united to form a single fibre

of raw silk. Another imported silk-moth
common in parts of the United States is the
Cynthia1 moth, whose larva infests Ailan-
thus trees. True American forms are the
brown Polyphemus 2 moth, whose larva is
colored light green, with oblique yellow
stripes; the Promethea3 moth, whose cocoon
is formed in a folded leaf which is securely
fastened by silk threads to its twig ; the

Nat. size. Pho-
to, by V. H. L.

FIG. 25. --Adult
female of Cll-
siocampa clis-

stria. From life. Cecropia moth, expanding six
inches, whose coarse tegumen-
tary cocoon is bound along
its whole length to a twig ; and the nearly
equally large Regal moth (^Citheronia regalls,
Fig. 23), whose larva is oar largest cater- male of ciisio-
pillar (Fig. 24). All of these species are
easily reared from the larvae or cocoons.

Closely allied to the Bombycidre are the
Tent-caterpillars, which arc never of great size. These are

campa. From
life. Nat. size.
Photo, by V.
H. L.

FIG. 27. — Egg masses of forest Tent-caterpillar, laid on branch. Photo, by

V. H. L.

1 A poetic name of Diana, from the mountain Cynthus.

2 The name of the fabled one-eyed giant blinded by Ulysses.

3 A name hi Greek mythology,

THE BUTTERFLY AND ITS ALLIES

destructive species, which infest apple trees and even forest
trees (Figs. 25 and 26). Eggs are laid in a ring-like cluster
around a twig (Fig. 27). Here they pass the winter and
hatch out in the spring as young larva1. The larvae are grc-

FIG. 28. — Nest of Clisiocampa tl/xxtria, the forest Tent-caterpillar, showing
the web and the way the larvae crowd together on it. Photo, by V. H. L.

garious and spin a tent-like web, on which they live when
not feeding (Fig. 28). When ready to transform, they
spin a cocoon made of a yellow powder mixed with silk.
The Noctuidae 1 (Owlet moths) are night fliers and are

1 From nox, night.

ZOOLOGY

attracted by our lamplights. They are the most numer-
ous of all our moths, eighteen hundred species being known
from our country. Among the largest members of this

group are the Catocala l moths already
referred to. Here also are placed the
boll-worm, which eats cotton-pods and
green ears of maize ; the cotton-worm,
which destroys the foliage of cotton ;
the army-worm, which devours grass
and young grain ; and the myriad cut-
worms, of which some gnaw off young
garden shoots at the level of the ground,
while other kinds ascend trees and de-
stroy buds. To the Noctuidse belong
also the Tussock moth (Fig. 29), whose
variegated larva bears dense brush-like
tufts of whitish hairs on the first four
abdominal segments, and is very de-
structive to shade trees in our cities ; the
Gypsy moth, lately imported into Massa-
chusetts, where the state has attempted
its annihilation ; and the Brown-tail
moth, also lately imported to Boston.
FIG. 29. — Notoiophus, The Geomctridae, or measuring-worms,

the Tussock moth. 1-1 ,1 -yr • i

The wingless female are< llke the Noctiuds, very numerous
is shown below a and very destructive. They are so

mass of e^ajs she has n i i ' ^i i i

just laid '"""Nat size called because the larvae have a way
From life. Photo. of proceeding, as it were, by inches in

their locomotion. One of the most im-
portant subdivisions is that of the canker-worms, which
often strip fruit and shade trees of their foliage.

1 /card, below ; /caXos, beautiful.

THE BUTTERFLY AND ITS ALLIES

The Pyralidae : include among other pests the bee-moth.
The larva of this species feeds upon the wax of the hive
and constructs silken galleries in the comb.

The Tortricidae 2 contain numerous small, inconspicuous
moths, whose larvre are, however, very destructive. The
codling-moth is a pest of the fruit-grower, for the larva
bores into apples and pears, causing them to fall prema-
turely. Many species are called leaf-rollers, from the fact
that the larva causes the leaf on which it feeds to curl.

FIG. .'X). — Case-bearing insects on a twig. Phot:), from life by V. H. L.

The Tineidae3 contain the smallest of the Lepidoptera.
Their wings frequently bear long fringes. The larvas are
so small that they often live in the interior of leaves, and
form winding or blotch-like "mines" in them. The larvae
of some species make a case out of pieces of leaves united
by silk, and carry this about with them. They are known
as " Case-bearers " (Fig. 30). Here also belong the clothes-

1 From Trvp, fire ; because the ancients believed these insects to arise
from and live in fire.

2 tortor, tortrir, winder, from tonjueo, to roll or wind ; with reference
to the habit of twisting up leaves.

3 tinea, moth.

30 ZOOLOGY

moths, of which we have three species. These moths fly
early in May, and lay their eggs on woollen cloth, furs, or
feathers, upon which the larvse feed.

This review of the Lepidoptera shows us that, on the
whole, despite their beauty, they are great enemies of
agriculture, since most of them feed on vegetable prod-
ucts. Not only do we in this country have an abundance
of native forms, but several exotic species have been im-
ported; and being thus removed from their natural enemies,
their natural fecundity has been unchecked, with the result
that they have brought great devastation upon vast agri-
cultural districts. The earnest attempts of a state to keep
down for a while an introduced pest, even at great expense,
is commendable.

The Hymenoptera l include bees, wasps, ants, and certain
less well-known insects. They all have four similar mem-
braneous wings as the Lepidoptera do ; but unlike the
Lepidoptera, their wings are not covered with scales, but
are transparent. The mouth parts are formed for biting or
for sucking, but the proboscis is not so long that it rolls up
as in Lepidoptera.

The Hymenoptera belong to one or the other of two
groups, — the stinging Hymenoptera, in which the female
is provided with a sting, and the boring Hymenoptera,
which are provided with an ovipositor, or long tube, by
which eggs can be placed at some distance below the sur-
face. To the first division belong the bees, wasps, and
hornets, certain digging or boring wasps, and the ants.
To the second division belong certain species,- -as, for
example, the ichneumon flies,- -which are parasitic on

1 v/j.r)v, skin, membrane ; Trrepov, wing.

THE BUTTERFLY AND ITS ALLIES 31

other insects, the gall-flies, or gall-wasps, and the plant-
eating Hymenoptera.1

The bees (Apidae2) include both social species and others
which lead solitary lives. Of the latter, some dig their
nests in the ground ; others are masons, and build their
nests of mud ; others are carpenters, and make tunnels
through pithy plants, or even solid wood ; while still
others are leaf-cutters. These leaf-cutting bees carve
circular disks from rose leaves, out of which they make
cells for their young.

Of the social bees, our native species belong to the
genus Bombus, — the "bumble' bees. The bumblebees
build nests in the ground.
The queens only survive the
winter. In the spring each
queen chooses some mouse
nest or other ready-formed
cavity in a meadow, and

places within it a ball of

TT , . „ , , FIG. 31. — Bombus, the bumblebee.

pollen. Jpon this iood she Nat. size. Photo, by W.H. c.i'.
lays eggs, which develop into

worker bees. As soon as the workers are full grown they
begin the task of gathering food, and the queen then de-
votes all her energy to egg-laying. Later in the season
males and young queens also appear in the nest. The
old and young queens dwell together in harmony until
autumn, when all the members of the colony perish except-
ing the young queens, which pass the winter in some
sheltered spot and form new colonies in the spring.

1 A key to the principal families of the Hymenoptera is given in the
Appendix to this Chapter, p. 42.

2 From apis, bee.

ZOOLOGY

The introduced, semi-domesticated honey-bees have
quite a different social economy. In the first place, the
nest is perennial ; consequently the young and old queens
cannot remain in the same hive, else the nest would
become overcrowded by the presence of too many families.
As }roung queens mature, the old queen seeks to destroy

them ; but she is usnsilly
forced out of the hive
by the workers, a num-
ber of which accompany
her. This migration is
what we call "swarm-
ing." 1 When several
young queens mature at
the same time, duels or
repeated swarmings en-
sue until only one queen
remains. When a new
colony is started in a
hive or hollow tree, a
comb is formed of wax
secreted by the worker
bees, and into this the
queen deposits eggs des-
tined to develop into

workers. Still later, eggs destined to form drones are laid in
cells larger than those in which workers develop. The de-
veloping young workers and drones are fed with honey and
bee-bread. Honey is derived from the nectar of flowers,
which is lapped up by the workers, is stored for a time in the
crop, where it undergoes certain transformations, and is then

FIG. ol«. — Swarm of bees. Photo, by
D. and S.

1 Fig. 31 a.

THE BUTTERFLY AND ITS ALLIES 33

regurgitated into the cells. The nature of the transfor-
mation of the nectar in the crop of the bee is not precisely
known, but it is not great enough to prevent the character-
istic flavors of the flowers of the buckwheat, orange, and
so on, from being retained in the honey. The bee-bread
is made from the pollen of the flowers, which is brought
into the hive on the hind legs of the workers. When a
new queen is needed for the colony, and the queen cells
are empty, one may be produced by the workers in the fol-
lowing manner : The partitions between three worker cells
are destroyed and two of the embryos are killed. The
enlarged cell is rilled with a special nutritive compound
manufactured by the workers and known as royal jelly.
The remaining embryo, fed upon this especially nutritious
jelly, develops, not into a worker, but into a queen.

Of the true wasps ( Vespidie !), some are solitary; others,
like certain of the bees, rear their families in the nests
of other species (guest-wasps) ; while still
others are social. The last group includes
our best-known species. The colony of
social wasps contains males, females, and
workers. As in the case of bumblebees,
only the females survive the winter, and in
the spring they build small nests and lay

worker eggs. The workers, when grown, FIG. re.— Poiistcs.
enlarge the nest and care for the numerous Slightly reduced.

, ,, n Photo, by W. H.

progeny ot the queen. Our social wasps c. P.
belong either to the p-enus Polistes,2 which

o o

includes the ordinary black, brown, or yellow bodied

wasps, which build mushroom-shaped nests behind window

blinds and under boards (Fig. 32), or to the genus Vespa,

1 From vespa, wasp. 2 TroXto-r^s, founder of a city.

ZOOLOGY

Xat. size.
H. C. P.

which includes the black and spotted hornets and yellow-
jackets, that build great masses of paper combs enclosed

in a nearly spherical gray paper
envelope (Fig. 33). These are
found attached to trees or parts
of buildings. The paper is made
of finely masticated wood-fibre
cemented b}~ a secretion. Certain
yellow-jackets form nests in the
ground. The hornets are well

FIG. 33. -Vespa, a hornet, known as among the most vindic-
Photo. by w. tive of our northern insects, and
their sting is capable of produc-
ing considerable pain. In all Hymenoptera the pain of
the sting is due to the introduction of a poison into
the body of the victim through the stinging organ. This
poison is secreted by a special gland of the insect.

The digger and mud wasps (Fossoria1) have the most
varied habits. One of the most familiar species is Pclo-
poeusf which somewhat resembles a true
wasp, but may be easily distinguished
from it by the long, slender attachment
of the abdomen to the thorax and by the
fact that the wings when closed lie flat
and horizontal (Fig. 34), while in the
true wasps they are folded like a fan.
Other species bore into the pith of plants
or make burrows in the ground. Many are
predaceous, feeding on spiders, cicadas, etc.

The ants (Formicidre 3) constitute a well-known group
having features so marked that other insects, excepting

1 From /ossor, digger. 2 TT^AOS, slime. 3 From formica, ant.

FIG. 34. — I
wasp, showing po-
sition of wings.
Xat. size. Photo,
by \V. H. C. P.

THE BUTTERFLY AND ITS ALLIES

the termites, will hardly be confused with them. From
the termites ants may be distinguished by the fact that the
first segment of the abdomen forms a small knot or scale
lying between the thorax and the remainder of the ab-
domen (Fig. 35).

The intelligence of ants is notorious. This intelligence
has developed in connection with a highly organized social
life. This social life is a communistic one. Homes are
built, food is gathered, wars are made, and domains are
defended bravely and loyally all for the sake of the entire
community. The individual is little regarded, and each

:'~ •• , - - . "

FIG. 35. — Camponotus, the carpenter ant. Uniformly black. Shows scale
behind thorax. Nat. size. Photo, by W. H. C. P.

one is born to a caste from which escape is impossible.
For, in addition to the distinction of sex characteristic of
other species, we have here workers, and these workers may
be of different kinds. Thus certain workers get food and
care for the young ; others, which serve as soldiers and
defend the colony or conduct war, are in some cases pro-
vided with powerful jaws. In some species there are three
or more classes of workers, each having its characteristic
form of body.

Ant Colonies.- -A colony is founded by a female. On
warm days the young males and females may leave the
nests and take flight in great numbers. This is the mar-
riage flight of the queens. Within a few hours after

36 ZOOLOGY

nightfall of the clay of this flight the males perish, while
the queens settle down to the ground, tear off their wings,
and each of them seeks an appropriate place to begin the
formation of a new colony. If by chance a queen is dis-
covered by some of her workers, she is cared for by them ;
otherwise she must get on alone. She makes a small nest
and lays eggs, which quickly develop into workers, which
then assume the task of constructing the nest of the new
colony. The nests of our ordinary species consist simply
of tunnel-like passageways dug in the ground and enlarged
at intervals to form small chambers. Most species dig
their nests preferably under protecting stones or the roots
of trees ; in other cases a hillock of earth and twigs, an
"ant-hill," is constructed. These mounds may attain a
diameter of from six to ten feet.

Ant Language. — In connection with their communal life
ants have gained a power of communication. By the
agency of their antennse, with which two comrades are
constantly stroking each other, they can tell each other of
the whereabouts of food, of the approach of an invading
army, or of the need of aid. They distinguish members
of their own community from those of other communities,
and recognize one of their number, even after a long ab-
sence, and receive it back to the colony with demonstrations
as of joy.

Social Life of Ants. — To illustrate the complex social life of ants,
a more detailed account is here given of certain interesting .species.
Certain ants, such for instance as our Formica1 difficilis? a rust-red
species often found living beneath large, flat stones, make slaves of
another species of ant which (a curious coincidence) is a dark-colored
species. In at least one slave-making species the jaws have become

i Ant. 2 Difficult.

THE BUTTERFLY AND ITS ALLIES

so modified to aid it in capturing slaves that it is absolutely dependent
upon its slaves for food, and it would die surrounded by food were
none of its slaves at hand to feed it.

The Agricultural Ant. — One of our most interesting ants is the
Agricultural Ant of Texas (^fyrmical molefaciens2). This ant makes
a circular clearing about its mound, upon which it allows only one
species of grass to grow. Indeed, some observers maintain that the
seed of this grass is planted upon the clearing
by the ants. Certain it is that the ripe seeds
of the grass are carefully harvested by the ants
and stored within the chambers of their mound.
From time to time the seeds are brought out and
dried to prevent sprouting. During rainy sea-
sons, when the seeds germinate despite all pre-
cautions, the ants are said to nip off the sprout
upon its first appearance.

The army ants, of which there are several
species, occur in great numbers in tropical South
America. Like many other species which live
by hunting, they migrate from a locality after
having exhausted it of their food. While on
the march, the young of the species are trans-
ported by some of the adults. When an army
of these ants approaches a place, every living
animal endeavors to escape. The breeding birds

must be on the alert to pick off the advance Fie. 3G.-Ptmpfapeda-

1 . hs, a parasite on the

guard to prevent them from returning to the

army with news of the presence of nestlings.
Insects of all sorts, young and old, fall a ready
prey to these swarms. Some spiders escape by
suspending themselves by their threads, and insects which resemble
leaves often find safety in keeping rigidly still. When an army of
these ants enters a house, the inhabitants find it wisest to leave
the invaders in possession, for in a few hours the house is cleared
of every living thing — moths, cockroaches, rats, mice, all have fled
or been devoured.

The leaf-cutting ants are another tropical American species. The

caterpillar of Clisio-
campa. Upper figure
female, lower male.
Photo, by V. H. L.

, ant.

2 Mole or mound builder.

ZOOLOGY

colony is very perfectly organized. The duties of the workers are
divided among different gangs. Thus, when a tree has been selected,
one gang ascends the trunk and cuts the leaves in pieces of a definite
shape. The pieces flutter to the ground, are picked up by another
gang and carried to the entrance of the ant-hill, where they are de-
posited to be carried into the nest by a third relay. The bits of
leaves are used to line certain of the passageways, and a fungus is
grown upon them which serves the ants as food. The leaves are
probably stored to provide this fungus food.

The parasitic Hymenoptera have the habit either of lay-
ing eggs in the body of another insect, — one of the plant-
lice, a caterpillar, or other species, — or else they lay their
eggs in the nest of some species of insect so that the larva
can make its own way into the host (Figs. 36-38). The
long, tail-like ovipositors of the female ichneumon are, in

some cases, used to drill
holes into trees occupied
by insect burrows so that
her eggs can be laid
therein. These parasitic
species are invaluable to
agriculture in keeping
down injurious insects.

The gall-wasps, popu-
larly not distinguished
from the strict gall-flies,
are familiar to us from
thei;1 works. They lay
eggs in various kinds of
plants, especially in oaks and members of the rose family.
An excessive growth of the plant tissue, called a gall, is
caused either by a poison dropped into the plant with the

FK;. -37. — Cocoons of Microgaster, a para-
sitic hymenopter, on a sphinx larva.
Photo, from the living object by V. H. L.

THE BUTTERFLY AND ITS ALLIES

egg, or by the irritation of the developing embryo.1 The
galls of gall-wasps are often more or less spherical masses

FIG. 38. — Ophion, an Ichneumon which infests caterpillars. Nat. size. Photo.

by W. H. C. P.

which are closed, in consequence of which the confined
insect must bore its way out. The galls made by the same

FIG. ol). — Larvae of saw-tiy on grape leaf. Photo, by V. H. L.

1 Cf. Fig. 69, p. 07.

ZOOLOGY

species of insect on one kind of tree are quite similar,
but if the same insect stings another species of tree, a
different kind of gall is produced. Also when different
species of gall-wasps sting one and the same leaf, the galls
will be unlike. Hence the characteristic form of the gall
is determined both by the species of plant and by the

species of insect which
lives in it. It is interest-
ing to collect galls, watch
for the emerging Avasps,
determine their species,
and thus get their entire
life history. The gall-
wasps are, on the whole,
injurious to agriculture.

The plant-eating Hy-
menoptera are extremely
destructive pests. The
young are known as
"slugs," from their re-
semblance to the true
slugs, which are snail-like
animals. They infest pear
trees and rose bushes, leaving scorched, dried leaves behind
them.1 Here also belong the currant-worm and the saw-
flies (Figs. 39 and 40;, which eat leaves like caterpillars,
but differ from them in having twelve or sixteen prolegs
instead of ten.

FIG. 40. — Eggs of Nematus, a saw-fly on
gooseberry leaf. Photo, by V. H. L.

1 See "The Pear Slug," in Circular No. 26, 2d Series, U. S. Depart-
ment of Agriculture, Division of Entomology.

APPENDIX TO CHAPTER II

KEY TO THE PRINCIPAL FAMILIES OF LEPIDOPTERA

ai. Antennae club-shaped at apex ; wings when at rest
held vertical (Fig. ID)

«.2. Antennae usually having the form of a bristle, spin-
dle, or thread, often with a comb ; wings at rest
held out flat (Fig. 23), or else folded over body
like a gable roof (Fig. 25).
l>i. Hind wing usually with one or two dorsal veins

[Macrolepidoptera, large-winged moths].
Ci. Antennae spindle-shaped or keeled, rarely
club-shaped ; wings small ; dusk fliers.
d\. Antennae prismatic ....

do. Antennae not prismatic, but

e\. attenuated at end, occasionally
pectinate ....

/!. Clear winged (Sesiina).
f.2. Wings speckled, antennae
much longer than head
(Cossina).
/3. Antennae hardly longer than

head (Hepialina).

BO. club-shaped, occasionally pec-
tinate ...

C2. Antennae bristle- or thread-like ; wings

mostly broad, night fliers.
d\. Wings when at rest placed like a
gable roof over body, or envelop-
ing it ; proboscis well developed.
e\. Subcosta of hind wing united with
radius for a considerable dis-
tance ; body hairy .

e». Subcosta of hind wing nearly or
quite distinct from radius ; ab-
domen ending conical ly .

PapilionidcB

(Butterflies)

Sphingidce

(IIa\vk-inoths)

Xylotropidaz

(Wood-borers)

Zygamidm

(Zygenids)

(Tiger-moths)

Noctuidce
(Owlet-moths)

42 ZOOLOGY

d%. Wings as in d\ ; proboscis usually
weak ; abdomen rounded at apex ;
antennae pectinate . . . Bombycidce

(Silk-worms)

ds. Wings rest horizontally ; proboscis

weak Geometridce

(Measuring-worms)

61. Hind wing with three dorsal veins [Microlepi-

doptera, small-winged moths].
Ci. Wings not divided or parted.

d\. Wings rest in gable fashion, with

short fringe or none at all.
e\. Anterior wings elongate-tri-
angular ; palps extending be-
yond head .... Pyralidce

(Pyralids)

62. Anterior wings much elongated,
cambered ; antennae with thick
basal segment ; palps slightly
protruding .... TortricidjR

(Leaf-rollers)

di. Wings at rest, flat or enveloping the
body ; the anterior wings with
long fringe ; strongly developed
palps Tineidce

(Leaf-miners)

c2. Wings divided or parted .... Pterophoridce

(Plume-moths)

KEY TO THE PRINCIPAL FAMILIES OF HYMEXOPTERA

a\. Trochanter simple ; female with sting.

61. First segment of the hind leg more or less
compressed, at least on inner side, and

often thickly hirsute Apidce

(Bees)

62- First segment of hind leg more or less cylin-
drical, neither markedly broadened nor
hairy.

APPENDIX TO CHAPTER II 43

* *

Ci. Anterior wings folded once lengthwise ;
antennce usually clearly bent at an
angle Vespidw

(Wasps)

c2. Anterior wings not folded lengthwise.
di. Abdomen appended or peduncu-
late, oval or broadest anteriorly,
gradually tapering posteriorly .

Superfamily Fossoria

(Digger and. Mud Wasps)
d2- Abdominal stalk formed of one or
two knots or scale-like rings ; an-
tennae flagellum-like . . . Formic-idai

(Ants)

«2. Trochanter of two segments ; female with ovi-
positor.

61. Abdomen not sessile, but appended or pedun-
culate ; anterior rings without lancet-cells;
hind wings with two root-cells .

Superfamily Entomophaga

(Parasitic and Gall-producing Ilymenoptera)

62= Abdomen sessile (or continuous with thorax) ;
anterior wing with lancet-cell ; hinder wing
with three root-cells . . Superfamily Phytophaga

^Plant-eating Hymenoptera)

CHAPTER III

THE BEETLE AND ITS ALLIES

BEETLES (Coleoptera1) can be distinguished from otliei
insects by the fact that the anterior pair of wings (elytra)
are modified to form two horny shields, covering the pos-
terior part of the body, while the posterior pair of wings
are membranous. The mouth parts are formed for biting.2

During development, the beetles, like the Lepidoptera
and Hymenoptera, undergo great changes of form. These
changes may be observed in the potato-beetle. In this
species the orange-colored eggs are deposited often in a
very regular manner on the under side of the potato leaf.
Here they develop for several days. In about a week,
however, the young, reddish, black-spotted larva, or "grub,"
emerges. Like the adult beetle, it has three pairs of tho-
racic legs. After feeding actively for two or three weeks,
the larva descends into the ground, forms a naked yellow

FIG. 41. — Larva of Lachnosterna, the June bug, at roots of aster. Photo, of

living animals, uat. size, by V. H. L.

s, sheath ; 7rrep6v, wing.
2 A key to some of the chief families of Coleoptera is given in the

Appendix to this Chapter, page 58.

THE BEETLE AND ITS ALLIES

pupa, and emerges in about ten days as an imago. From
two to four broods are produced during the year. The
adult beetles hibernate in the ground, emerging and laying
eggs the following spring.

The larval habits of the different kinds of beetles are
extremely varied, quite as varied as the habits of the adult.
The details of these differences may be best considered
when we take up the different kinds of beetles.

The number of species of beetles which have been de-
scribed is very great, probably over one hundred thousand.
Of these, over ten thousand inhabit America, north of
Mexico. Fortunately this vast number can be included
within a relatively small number of families. Leaving
the precise definition of
these families to the
table in the Appendix,
we mav here consider

•/

certain of the salient
general characteristics.

The running beetles
include two principal
families. The first of
these is the tiger-beetles
(Cicindelidse :), which

are colored bright brown or green. They frequent sunny
places, especially paths or sandy shores, and are extremely
agile.2 The larva' are hunch-backed creatures, have a huge
head armed with long jaws, and live in burrows, at the
entrances to which they lie in wait for their prey.

The second family of the running beetles includes the
ground-beetles (Carabidae3 in narrow sense). This family

1 Derived from candda, caudle. 2 Fig. 42. 3 Kapafios, beetle.

FIG. 42. — Three common species of Cicin-
dela, the tiger-beetle. Left, red-copper
bronze; middle, brown, with yellow mark-
ings; right, bright green, cream-colored
markings. From Packard.

ZOOLOGY

is composed of about ten thousand species, of extremely
varied form, size, and coloration. Most of them are of a
shiny black color, usually with longitudinal ridges or rows
of piinctations on the elytra.1 They live on the ground,
and during the daytime they are concealed underneath
boards and stones, but at night they fly and climb trees
and shrubs in search of other insects. They are most
abundant near watercourses, and are sometimes found on
the seashore. Some species emit ill-smelling fluids, often

with a popping sound. These
fluids serve to defend them from
their enemies. Some species are
vegetable feeders, for instance
one species whose larv?e are
destructive in the South to
young Indian corn.

The next two families, Dytis-
cidae2 and Gyrinidae,3 include
beetles which are quite as de-
structive to animal life of the
water as the runners are to those
of the land. The Dytiscidse are
often large species, which have long, thread-like antenme.
The Gyrinidce have short antennse and whirl around on
the surface of the water, often in groups. Each eye is
divided into an upper half, used for looking into the air,
and a lower half, used for looking into the water. The
larvre of both of these families have a long and spindle-
shaped or flattened body and live in the water.

1 Fig. 43.

2 dvT-r)s, diver ; Sun/cos, fitted for diving.

3 From 70/30S, circle ; because this beetle swims in a circle.

FIG. 4-'i. — Calosoma scrutator, the
searcher, a ground-beetle. Nat.
size. Photo, by AV.H.C.P.

THE BEETLE AND ITS ALLIES

Another family of aquatic beetles includes Hydrophilus l
and its allies, which are less strictly carnivorous than the
last two families. Their antennae are
short and club-shaped, and their bodies
are plumper than that of Dytiscus, which
is of about the same size and lives in
similar places.

The next family includes certain
short-winged beetles (Staphylinidte 2),
so called because the elytra cover only
a small part of the abdomen (Fig. 44).
These beetles (" rove -beetles") are usu-
ally black and of small size. They
are very common under decaying or-
ganic matter, stones, and other objects
lying on the ground. They run swiftly. Some species
mimic ants and wasps. Not only do they resemble these

FIG. 44. — A
gus, a staphylinid.
From Packard.

FIG. 45. — A staphylinid elevating the abdomen. Photo, by W. H. C. P.

Hymenoptera in the general form of the body, but also in
the movements of the tip of the abdomen, which, when the

1 i>5ajp, water ; 0/Xos, loving.

2 (rTa^i/AZVos, from crra^iyXiy, a cluster, is Aristotle's name for a certain
insect.

ZOOLOGY

animal is irritated, is raised as though to sting (Fig. 45).

These beetles feed upon decaying animal and plant matter;

consequently they are useful scavengers. Some species in-
habit the nests of ants and of termites,
but their relations with their hosts are
unknown. The larvae are not unlike the
adults, and inhabit similar situations.

The carrion or sexton beetles (Silphi-
dre l) are usually of medium or large
size, and are either stout-bodied, with
red spots on each elytron (Necro-

phorus2), or very much flattened and
FIG. 46. — Silpha amer- .,,,-,/ -, -, ^ ^.,, ,,. ...

icana, a carrion bee- with thin-edged elytra (Silpha, -b ig. 46).

tie. From "Standard rpjie Species of NecropllOrilS are power-
Natural History." *

ful animals. When one or more pairs
of these beetles discover a dead bird or small mammal
on the ground, they dig out the earth from underneath
and pile it upon the animal until eventually the car-
cass is entirely buried. Then
the female deposits her eggs
upon the body, so that a rich
supply of food is provided for
the young larvre which hatch
from the e^o-g. The members

r IG. 4(. — Antnrenus, the niuse-
of the geilUS Silpha do not bury um pest, a dermestid. Left,

a carcass, but live and rear their la!'^: "lkldl£ f1^' ri-ht'

adult. From Packard.

young beneath it.

While the families of beetles hitherto considered are
in general useful to man by acting as scavengers or by
destroying insects injurious to vegetation, we have now

1 <ri'X0i7, an ill-smelling insect.

2 i>eKp6s, a dead body ; <£f/ocj, to bear.

THE BEETLE ANT) ITS ALLIES

name from the resemblance of their long, often

to consider a family, that of the Dermestidae,1 which is
economically directly injurious in a variety of ways. The
species of this family include small, oval, or elongated
beetles with gray or brown markings, which are due to
scales and can be rubbed off. The larvae are fuzzy, and
are more injurious than the imagos. They feed on wool,
leather, fur of all sorts, as well as on dried and salted
meats. Our most destructive species have been imported
from Europe. One of them is the carpet-beetle or "buf-
falo-bug," which lives upon carpets and clothing. The
museum pest is a closely related species which works sad
havoc with insect collections, unless these are subjected
several times a year to the poisonous fumes of carbon
disulphide (Fig. 47).

The stag beetles (Lucanidee 2) have received their com-
mon

branched mandibles to the antlers of a
stag. The plates of the club-shaped
antenna cannot be brought compactly
together, as in the next family. The adult
beetles live on the sap of trees, and the
larvre bore into the wood of the roots and
trunk. The common large stag-beetle,
which is often attracted into our houses by
lamplight, is Lucanus dama. In the South
the giant stag-beetle {Lucanus elepJians) is
found, with mandibles which, in the case of
the male, are more than three-fourths the length of the body.

Closely allied to the last is the great family of lamelli-
corn3 beetles, in which the ends of the antennae bear flat,

1 Sep/j.r)<rrr)s (5fy/ia, skin; e<r0t'u>, to gnaw), a worm which destroys pelts.

2 From lucus, grove. 3 lamella, a small plate or leaf ; cornu, horn.

FIG. 48.— Dorcus,

a stag - beetle.
Nat. size. Photo.
by W. H. C. P.

ZOOLOGY

•

closely applied plates. This family includes many very

large insects. We can separate it into two groups, - - the

scavengers and the leaf-chafers.

The scavenger lamellicorns, commonly known as tumble-
bugs, live in the dung of horses and cows, which they form

into balls and roll long distances
(Fig. 49). The dung-rolling habit
has long excited interest ; indeed,
among the Egyptians it was a
source of superstition. So high
was the veneration of this people
for this their sacred beetle, that
they reproduced it in their paint-
ings and sculpture. The ball of
dung is really intended for the dep-
osition of an egg, and it is rolled
by both males and females to a hole

in the ground which has been dug in a safe place for its

reception.

The leaf-eating lamellicorns include the May-beetles or

"June-bugs' (Lachnosterna1) which are attracted by

lamplight at night. They enter with a

busy humming sound, soon come in violent

contact with the wall or a piece of furni-
ture, and fall heavily to the floor. They

feed at night upon the foliage of trees and

shrubs. Another common species is the

rose-bug,2 which bears the name Macro-

dactylus 3 subspinosus. It is destructive to

the blossoms and young fruit of grapes,

FIG. 49. — Copris, a tumble-
bug. Nat. size. Photo, by
W.^H. C.P.

n sheep's wool ; arepvov, the chest.
2 Fig. 50. 3 /^a/epos, large ;

finger.

FIG. 50. — Macro-
dactylus, the
rose-bug. Nat.
size. Photo, by
W. H. C. P.

THE BEETLE AND ITS ALLIES

FIG. 51. —

rujlpes, a metallic
wood-borer. From
"Standard Natural
History."

roses, and other members of the plant family Rosaceae.

The larvae of the May-beetles are the fat, whitish, bowed

grubs which are often found in the spring in the soil where

they have passed the winter. They are

very destructive, for they feed on roots of

grass, herbs, and shrubs (Fig. 41).

Another family of beetles very destruc-
tive to trees is that of the metallic wood-
borers or Buprestidae.1 The adults are

found upon flowers and the bark of trees,

where their metallic colors glitter in the

sunshine (Fig. 51). The larvae, which

have relatively enormous heads, bore

beneath the bark of trees or into the

wood. This family reaches its highest

development in the tropics.

Closely allied to the foregoing is the family of click

beetles or Elateridae.2 These have the power, when placed

on their backs, of leaping into the air by
means of a special device on the under
side of the animal (Fig. 52). The larvae,
called "wire-worms' because of their
round, hard bodies, live under the bark
of trees and in rotten wood or upon vegeta-
tion in the ground. They are most de-
structive to germinating grain, especially
maize. It requires several years for them
to mature.

The fireflies (Lampyridae3) make up

?, among the ancients a poisonous beetle, living in grass by
swallowing which oxen (/SoOs) swell out (trp^d^ .

2 eXariyp, driver. 3 Xd^Trw, to shine ; oupd, tail.

FIG. 52.— One of the
click beetles.
Nat. size. Photo,
by W. H. C. P.

ZOOLOGY

another and a well-known family. They are distinguished
by soft wing-like elytra and by the great expanse of the

thoracic shield, which
partly or wholly covers
the head. Certain non-
luminous species live on
flowers, especially the
golden-rod ; the lumi-
nous species are noctur-
nal. The light-giving or-
gan lies in the abdomen.
The larv?e also are lumi-
nous and are known as
glow-worms (Fig. 53).
A family of consider-

FIG. 53. -- Photuris, a firefly. «, larva; - .

b, adult. The lines to the left of figures able economic import-
represent actual lengths of animals. From £ince js that of the TenC-
Packard. .

briomdae, so called from
the principal genus Tenebrio,1 the
larva of which, known as the meal-
worm, occurs in flour and cereals
and looks much like a wire-worm.2
The adult beetle is black and about
one-half an inch long (Fig. 54).
The family is not abundant in the
northeastern part of the United
States.

0 i i • i f i i^ i ,1 FiG.54. — Tenehrio, the meal-
Several kinds Ot adult beetles worm Left, larva; right,

can be found under the bark of adult. From Leunis.

1 Miller, because it lives in flour.

2 These larvse are reared by bird-fanciers for bird food, and may be
obtained in bird stores.

THE BEETLE AND ITS ALLIES

trees, but these are mostly carnivorous and are seeking
their prey there. The minute bark-borers or engraver
beetles (Scolytidie1), however, feed on the innermost layer
of bark. As they eat in lines, a pattern is formed which
is characteristic for each species. Along these lines, niches
are made in which eggs are laid and larva? hatch. The
borings are injurious to the trees, often causing their
death. Herbaceous plants also are infested by certain spe-
cies. An example is the destructive Pine Borer (Fig. 55),
which is common throughout the United

States and Canada.

One of the most injurious

of all the families of beetles

is that of the weevils (Cur-

culionidse2). These beetles

are small, and their heads

are drawn out into a long

snout by which they bore

holes in plant tissue to

receive their eggs (Fig.

56). The dull colors of

the beetles render them in-
conspicuous to insect-feeding birds. The number of species
is reckoned at over ten thousand, and the family is of world-
wide distribution, its dispersion having been aided by com-
merce. Grain-weevils are great pests in stored wheat, rice,
or maize. They also oviposit in the planted seeds. Buds
are attacked, and nuts, stone fruit, and fleshy fruits are
made " wormy ' by them.

Extremely destructive also is the great family of long-

FIG. 55. - - Den-
droctonus, an
engraver bee-
tle. Magnified
2. 5 times. From
" Standard Nat-
ural History."

FIG. 56. - - Balani-
nus, a weevil, of
brown color.
From Packard.

1 From o-KoXuTTTw, to mutilate.

2 curculio, a grain-weevil.

ZOOLOGY

horned beetles, "buck-beetles," (or Cerambycidse1), of
which about six hundred species are known in North

America alone. The an-
tennae and legs of these
beetles are very long.2 The
larvae bore into even the
hardest woods, and live in
the wood for two or three
years. Timber and shade
trees are thus greatly dam-
aged. A favorite collect-
ing ground for Ceramby-
cidre is the golden -rod,
where the black, yellow-
banded locust borer, Cyllene
robince (Fig. 59), is pretty
sure to be found.
Still another destructive family is that of the leaf-eating
beetles, — the Chrysomelidre,3 to which the potato-beetle
belongs. These beetles are thick
and round in shape. They lay
their eggs upon the leaves of
plants. The larv?e feed on the
leaves or burrow in the stem.
Usually the larva is conspicu-
ously colored and exposed, and
relies for protection upon its dis-
agreeable odor and taste. The
most destructive species to agri-
culture in the northern United

FIG. bl. — Prlonus laticollis, a long-
horn. Black. Nat. size. Photo, by
W.H.C.P.

FKJ. 5<S. Orthosoma
net/ in.

bnin-

the straight -bodied

a beetle with lon horns.

Prionid. Brown color. Nat.
size. Photo, by W. H. C. P.

2 Figs. 57 and 58.

3 chrysomela, gold beetle, from xPVffb*> gold, and /^Xoy, apple.

THE BEETLE AND ITS ALLIES

States is the ten-lined Colorado potato-beetle, Doryplwra1
decemlineata. Until about 1859 this species fed upon the
sand-bur {Solatium rostratmiri), at the eastern base of the
Rocky Mountains and south into Mexico.
With the advent of settlers and the plant-
ing of the cultivated potato (Solanum
tuberosum, a native of Mexico), this more
thrifty, cultivated species was adopted as
its food-plant, and the potato-beetle began
its eastern migration. It spread slowly at
first, but within fifteen years had reached
the Atlantic coast. The little red, yellow,
and black asparagus-beetle, the yellow,
black-striped cucumber and melon beetle,
the tortoise-beetle, whose broad, iridescent,
translucent elytra are conspicuous on the
leaves of the morning-glory, nettle, and
other plants, all belong to this family.

So long has become our list of destructive
beetles that it is with satisfaction that we
turn at the end to a family which is almost
wholly beneficial to the vegetable kingdom,
as well as to most vegetable-feeders, includ-
ing man. This is the ladybird family, FIG. 59. —
Coccinellidce. These beetles are preda-
ceous, both in the larval and adult stages,
feeding upon small insects and insect eggs
(Figs. 60 and 61). They are especially
active in freeing plants from scale-insects and plant-lice.
So rapidly do the latter multiply that were it not for the
voracious larvse of the ladybird most plants would be

1 5opv<f>6pos, spear-bearing.

robin&, the locust
borer, found on
the golden - rod.
Photo, by W. H.
C. P.

ZOOLOGY

destroyed in a single season. The larvte of the ladybirds
are dark, spotted, and hirsute. One of the commonest of

our eastern ladybirds is a red-
backed, two-spotted one (Adalia
i>'' pun data).

The food of beetles is, as we
have seen, extremely varied, pIG. <;i.

more varied, indeed, than that of Anbtisocel-
FIG. CO.— Pupa of ,, if-- lata. Adult.

Aiiatisvcellutaon anJ Other Order Ot insects ; WOOd- Nat. size.

a leaf. Nat. size, fibre, bark of living or dead trees, Photo- b^

Photo, by V.H.L. . , V.H.L.

leat and stem tissue, nuts, truits,

grains, insects, adult and larval and dead animals of vari-
ous sorts, are all utilized by them as food. Those beetles
which destroy living plants, or which feed on fruits
and grains utilized by man, those which burrow in tim-
ber, devour meat or articles of human
industry and collections prized by man,
may be ranked as economically injuri-
ous. One species, indeed, is injurious
as a parasite of a useful animal ; this is
a curious beaver parasite, Platypsylla 1
castoria,2 In so far as certain predaceous
beetles feed upon other carnivorous
species of insects, as do certain tiger
carrion beetles, or upon small fish,

FIG. fi2. — Platypsylla
castoria, the beaver as do some of the Dytiscidse, or upon

parasite. From -• j. • i TI • -IT P.I

Packard. domestic bees, like certain allies ot the

weevils, they may be indirectly injur-
ing man. Of all the families of beetles, probably the leaf-
eaters cause greatest destruction ; next to them come the
weevils, followed by the Cerambycidse and the others.

s, broad ; \j/v\\a, a flea.

2 Fte. 62.

THE BEETLE AND ITS ALLIES 57

Every part of the plant has its coleopterous enemy. As
Le Conte and Horn have said: "As the function of the
Cerarabycidse is to hold the vegetable world in check by
destroying woody fibre, the Brnchidiu (weevils) effect a
similar result by attacking the seeds, and the Chrysome-
lidte by destroying the leaves.-"

The list of beetles directly or indirectly useful to man
is small. The carrion-beetles, tumble-bugs, and rove-
beetles, which feed upon decaying animal and vegetable
matter, are useful as scavengers. Of those which serve us
by killing other insects injurious to vegetation, the lady-
bird beetle stands first. The economic importance to us of
this one family can hardly be estimated. Different kinds
of ladybirds feed on different species of insects. At one
time it seemed that the orange industry, if not that of fruits
in general, was doomed in California on account of the
destruction wrought by the introduction of a scale-insect.
As the insect had been imported, we had no native beetle
which attacked it. Search was made abroad, and a lady-
bird beetle was found in Australia which feeds on this
particular scale-insect. The Australian beetle was intro-
duced into California, and now the scale-insect is subdued.
The larva; of some of the checkered beetles l feed upon the
larvas of boring beetles, while the larva} of tiger-beetles
watch at the mouth of their burrows for other insects upon
which they feed. Carabid beetles are said to ascend trees
in search of canker-worms. Larva} of ground-beetles prey
upon the pupating plum Curculios. Other beetles eat cut-
worms, and infest the common wasps.

One beetle, the blister-beetle, known in the markets as

1 A family of rather small beetles, living in flowers and on trees, and

often with, contrasting colors.

58 ZOOLOGY

the Spanish fly, has been for ages used as a drug. When
disturbed, there exudes from the joints of this insect a
liquid serving as a protection, since it burns or blisters the
disturber. This property is retained in the extracted or
dried substance. The article sold in drug stores is ob-
tained from crushing the dried beetle. The larvse of vari-
ous beetles have been prized as food by certain peoples
from the Romans of Pliny's time down to the present,
for they are eaten with relish by certain tribes of South
American Indians. Fireflies sewn in lace are sometimes
worn by the Spanish and Cuban women as adornments for
evening dresses, while other beetles with particularly hard
and beautifully colored and iridescent wing-covers are used
as settings in hat ornaments and buckles, as well as in
jewels.

APPENDIX TO CHAPTER III

KEY TO THE PRINCIPAL FAMILIES OF THE COLEOPTERA

(The terminology of the key may be understood by reference to the figures

on page 59.)

a\. Hind tarsi with five segments, as likewise also
usually the other tarsi, certain aquatic families
excepted [Pentamera] .

T>I. Elytra, short, exposing nearly whole of abdo-
men . Staphylinidce

(Rove-beetles)
&o. Elytra, nearly or quite covering abdomen.

GI. Antennae bent, first segment long, ter-
minating in a club made of applied
lamella?.

di. Lamellae closely applied and flat-
tened . LnmrtUcornia

(Lamellicoras)

dz- LamelUe not closely applied ; man-
dibles very large .... Lucanidce

(Stag-beetles)

APPENDIX TO CHAPTER III

FIG. 62o. — Under surface of Harpalus,
a ground-beetle. After Le Conte.
a, lignla ; b, paraglossse ; c, supports
of labial palp1 ; d, labial palp ; e, men-
turn ; f, inner lobe of maxilla ; y,
outer lobe of maxilla; h, maxillary
palp ; i, mandible ; k, buccal open-
ing; I, gula or throat; mm, buccal
sutures; o, prosternum ; p', epister-
num of prothorax ; p, epimeron of
protborax; q, qf, qff, coxre; r, r' , >",
trochauters ; s, •••', s", femora or
thighs; t, t', t", tibiae ; v, V2, Vs, etc.,
ventral abdominal segments ; w,
episterna of mesothorax (the epim-
eron just behind it) ; x, meso-
sternum : ?/, episternum of meta-
thorax ; yf, epimeron of metathorax ;
z, mctasternum.

1 1 ho leader should run to base of hibial
palp, d.

FIG. 626. --Upper
surface of Necro-
phorus, a carrion
beetle. After Le Conte. a,
mandible: 6, maxillary palp;
c, labrum1; d, epistome ; e,
antenna ; y. vertex of head ;
/;, back of head; •/, neck;
/.prothorax; m, elytron; n,
wing or hind wing ; o, scntel-
lum (of mesothorax) ; p, dor-
sal surface of metathorax; q,
femur or thigh ; r, r'2, r3, etc.,
dorsal abdominal segments;
s, s'2, .s3, etc., spiracle openings
or stigmata; t, t', t', tibiae;
v, tibial spurs; iv, tarsi.

1 The leader should run to the V-shaped piece in
front of d.

ZOOLOGY

Antennae straight, or, if bent, not ter-
minating in lamellate club.
di. Maxillary palp as long as or longer

than antennae . HydrophilidoB

( Water-scavengers )
dz- Maxillary palp clearly shorter than

antennae.

d. Six to seven ventral segments,
or if only five, the first 3 or 4
are grown together,
/i. Anterior coxse spherical or
transverse, projecting
little from the coxal
cavity.

<7i. All legs used in run-
ning or walking . Carabidce

(Eunners)

g.2. At least the hinder
legs used for swim-
ming

/2. Anterior coxse conical or
tooth-like, projecting
prominently from coxal
cavities.

gi. Anterior coxse coni-
cal ; abdomen com-
posed of six rings .

~] DytiscidoB

(Divers)

i Gyrinidw

} (Whirligigs)

Silphidas

(Carrion-beetles)

ffz-

Anterior coxas ap-
proximately cylin-
drical ; c u t i c u 1 a
soft, leathery

Abdomen composed of five rings.

/i. Anterior coxas spherical ;

prothorax with a pro-

cess resting in a depres-

sion of the mesothorax.

gi. Not capable of leaping

into the air

Lampyridce

(Fireflies)

Buprestidce

(Metallic Wood-borers)

APPENDIX TO CHAPTER III 61

gr2. Capable of leaping into

the air . . Elateridai

(Click-beetles)

/2. Anterior coxae conical, pro-
truding from coxal cavi-
ties .... Dermestidai

(Dermesticls)
Hinder tarsi 4-jointed ; anterior and posterior

tarsi, 5-jointed [Heteromera].
&i. Fore coxse separated, more or less enclosed in

coxal cavity Tenebrionidcv

(Meal-beetles)

b-2- Fore coxae near together, protruding ; neck
evident ; elytra broader than attachment to
thorax ....... Meloidce

(Blister-beetles)

Tarsi apparently 4-jointed, really 5-jointed, with
very small, hidden, penultimate segment [Cryp-
topentamera] .

61. Head drawn out into proboscis . . . Curculionidcv

(Snout-beetles)

62. Head not drawn out into proboscis.

Ci. Head prominent ; antennae usually as

long as or longer than body . . Ccrambycida.'

(Long-horns)

c2. Head short, sunk in thorax.

d\. Antennae short, bent, with thick

terminal knob .... Svolytidm

(Engravers)

<?2. AntennaB thread-like or beaded . Chrysomelidce

(Leap-beetles)

Hind tarsi apparently 3-jointed, really 4-jointed,
with inconspicuous penultimate joint [Crypto-
tetraniera]. Short head, without clearly marked-

off thoracic shield Coccinellidce

(Ladybirds)

CHAPTER IV

THE FLY AND ITS ALLIES

THE term "fly" is applied to many of the insects belong-
ing to the Diptera 1 or group of two- winged insects.2 It is
strictly applied to the family Muscidse.3 The most gener-
ally known representatives of this family are the house-fly
with a sucking mouth, the stable-fly with a mouth fitted for
piercing skin and sucking blood, and the blow-fly with a
steel-blue abdomen. These flies love sunshine and dry ness.
On a bright day they fly actively in the open air. On
damp days, on the other hand, they swarm into houses and

1 5/s, twice ; irrepbv, wing.

2 The following is a key to the principal suborders of the Diptera : —

ai. All three thoracic segments fused, usually winged ;

under lip unsegmented.
61. Adults not parasitic ; maxilla; covered by upper

lip.
d. Antennae long, many-jointed . . . Ncmatocera

(Gnats and Midgets;
c2. Antenme short, usually 3-jointed ; the third

joint ringed Bracliycera

(Flies)
62- Adults parasitic ; upper lip enveloped by max-

illse as by a sheath Pupipara

(Ex. Sheep-tick)
«2. The three thoracic segments separate, no wings,

under lip segmented . . Aphaniptera

(Fleas)

3 musca, fly.

THE FLY AND ITS ALLIES 63

stables to avoid the wet, and otherwise show so great a
sensitiveness to moisture that we predict rain by their
stickiness and general increased ability to annoy. Both
the house-fly and the stable-fly are abundant about stables,
where their eggs are laid, and also about household pro-
visions.

The different species of flies require different kinds of
food, and the food of the larvae is usually different from
that of the adult. Thus the larva of the house-fly develops
in horse manure and various other kinds of filth, while the
adult feeds chiefly upon fluids or substances which can
be dissolved by their saliva and then sucked up. The
larva of the stable-fly lives in and feeds upon horse manure.
The adult sucks blood. The larvae of the blow-fly develop
in meat, cheese, or nitrogenous vegetable material.

The development of flies is rapid. One or two hundred
eggs may be laid by a single individual. These, in warm
weather, hatch in a few hours into larvae, commonly called
" maggots." The larvae are wholly footless, and even the
head is only a slightly developed structure. The larvae
acquire full size in about a week ; pupate and hatch about
a week later. The process of pupation is a complicated
one, for all the larval organs, excepting certain patches of
tissue, are destroyed. By the growth of these patches the
individual is formed anew. These changes are all deep
lying, and nothing seems more passive than the brown
pupal case. Finally the case breaks at one end, and the
fully formed fly emerges. The metamorphosis which the
fly has just undergone is a complete one.

The larvae as well as the adult flies breathe, like other
insects, by means of a system of air-tubes, which begin
with slits in the body wall, stigmata, and pass inward to

64 ZOOLOGY

all parts of the body- -the muscles ami all other internal
organs. These air-tubes are called trachea. They can be
seen best in some aquatic larvae with the aid of a strong
magnifying-glass. Air is driven in and out of these tubes
by means of expansions and contractions of the body wall.

Although so very numerous, flies would be still greater
pests if it were not for the fact that they are preyed upon
by various parasitic animals and plants. The larva of the
house-fly is sometimes infested by minute hymenopterous
parasites. A still more important foe is a minute plant -
a fungus called Empusa1 muscce2- -which infests house-
flies in the autumn. The dead flies may often be seen on
window panes with fine white threads sticking out of the
body, and surrounded by a halo made up of the spores
discharged from the fungus upon the glass.

The order Diptera is a large one and a difficult one to
study, for it contains many species and many of the
species are composed of small individuals which are
comparatively unknown. The members of the group can
usually be distinguished by having only two wings, the
posterior pair being rudimentary and transformed into
knobbed " balancers." An account of the principal fami-
lies follows.

The short-horned Diptera (Brachycera3), to which family
the house-fly belongs, includes flies in which the third seg-
ment of the antenme is unsegmented, called true Brachy-
cera, and flies in which the third segment of the antennae
is segmented, called anomalous Brachycera. The true
Brachycera include, besides the common flies, several
other common or especially interesting flies.

a hobgoblin. 2 Of a fly.

i'S, short ; /ce'pas, horn or antenna.

THE FLY AND ITS ALLIES

A member of the family Muscidse, which is especially
destructive in tropical Africa, is the tsetse-fly (Fig. 63).
The bite of this fly is so dangerous that horses and dogs
cannot penetrate the region infested by it. Even herds of
cattle may be killed by this fly. Consequently travellers
have been hindered in penetrating into this country, and
the opening up of tropical Africa to agriculture and com-
merce has been much interfered with. The injurious

FIG. 63. — Glossina morixtans, the tsetse-fly.
From the " Standard Natural History."

FIG. Gi. — Syrphus.
Packard.

From

effect of the bite of this fly is due to a parasite introduced
by it into the body of the victim.

Another destructive family includes the bot-flies (CEstii-
dte1), which have a general resemblance to honey-bees or
bumblebees. Their larvae are parasitic in mammals. Of
this family the bot-fly of the horse, Grastropkilus 2 equif is
the most generally known. These flies hover about the
legs of horses and lay their eggs upon the horse's hair.
The larvse, irritating the horse's skin, are licked by the
horse into its mouth and swallowed. In the stomach or

1 o/crrpos, gadfly.

2 7CKTT77/), belly ; 0tAe'w, to like.

3 Of the horse.

ZOOLOGY

intestine of the horse they get abundant food, and there
they develop. The larvae of another species, u the ox-
warble " or "grubs," are taken into the mouth of cattle,
and live for a time in the oesophagus. Then they bore
their way through the walls of this tube, and travel on
until they make their way out through the skin to the
surface. Another injurious species is the sheep bot-fly,
whose larvae cause " staggers ' in sheep.

The Syrphidae,1 like the bot-flies, mimic honey-bees,
bumblebees, and wasps.2 The adults feed on the pollen
and nectar of flowers, and even imitate the humming of
the bee. The larvse of some forms feed upon plant-lice ;
others, upon decaying vegetable matter. They may occupy
the nests of various stinging Hymenoptera. The larvee
of some species are known as rat-tailed maggots on account

of their having a characteristic append-
age. These are sometimes found floating
in foul water or even in salt water.

The robber-flies (Asilidse 3) are usually
of large size, have a short head, prominent
eyes, legs covered with stiff hairs, and
abdomen either long and slender (Fig.
65), or stout. These flies attack and de-

FIG. 65. --Bobber- tj fl>es ^ insects mucll

Hy. Nat. size.

Photo, by AV. H. larger than themselves, such as bumble-

f P

bees and dragon-flies.

The horse-flies (Tabauiclse4) include the large mourning
horse-fly, Tabanus astratus, which is of a uniform black
color, the white-lined Tabanus, T. lineola (Fig. 66), and
the smaller golden-headed horse and ox flies with banded

crvp<f>6s or o-ep0os, a small winged insect.

- Fig. 04.

3 From asihts, a gadfly.

From tabanus, the gadfly of Pliny.

THE FLY AND ITS ALLTES

wings (Fig. 67). Only the female sucks blood, while the
male feeds in flowers. They are powerful and rapid fliers.
The larvae are carnivorous and live in the earth or water.

FIG. 66.--Tdbanus Ihieola, white-
lined horse -fly. X 1.2. Photo, by
W. H. C. P.

FIG. <>7. — Chrysops, handed horse-
fly. X 1.5. Photo, by W. H. C. P.

The black-flies (Simuliidse r) are representatives of the
long-horned flies (Nematocera). They are familiar pests
in the forests of our Northern country. The females, which
alone suck blood, occur in such num-
bers and are so active that they render
certain places almost uninhabitable to
man. Their bite often produces wide-
spreading and painful inflammation,
accompanied by swelling (Fig. 68).
The larvse are aquatic. The Southern
black-fly or " buffalo gnat ' sometimes
causes the death of domestic animals.

The gall-gnats (Cecidomyidse 2) are
minute flies which lay eggs on plants. The larva? make
their way into the plant tissue, and cause the further de-
velopment of the tissue to be abnormal, so that excrescences

FIG. (J8. — Simulium,
the black-fly. En-
larged. From
Packard.

1 From shmtl, together ; or simultas, a hostile encounter.

2 KTJKI'S, gall-apple ; /xi»?a, fly.

ZOOLOGY

or galls are produced. The galls are formed only in grow-
ing tissue such as the tips of branches, buds of flowers or
growing leaves, and are less striking on the whole than the
galls of Hemiptera (Fig. 69). A certain kind of gall-fly,
called Hessian-fly (Fig. TO), is extremely injurious to wheat

FIG. (>'-.). -- Plant galls produced by Hemiptera and Diptera. 1. Pine-apple
on twigs of the spruce fir produced by the spruce-gall Aphis (U/iennes
abretis, one of the Hemiptera). 2. Covering gall on the petiole of the pyra-
midal poplar (Populus pyramidalis), produced by Pemphigus burxarius,
one of the Hemiptera. :>. Covering galls on an ash leaf (Fraxinus excelsior) ,
produced by Diploxi-t bnftdaria (Diptera). 4. Covering gall on Pistacia
(Pisfacia lentiscu.fi}, produced by PenipJiif/ii* rornii'tdarhifi. 5. Solid galls
ou the cortex of Dnvana lonyifolifi, produced by Cecidoxes eremite (Hemip-
tera) . (>. Longitudinal section of one of these galls. 7. Capsule galls on the
leaf of the turkey oak (Quercus cerris, Hemiptera), produced by Cecidomyia
cerri*. 8. One of these galls cut through, with the operculum still firmly
attached. 9. The same, with the operculum falling away ; X 3. The remain-
ing figures natural size. From Kerner, " Pflanzen Leben."

THE FLY AND ITS ALLIES

because it infests wheat seedlings and so weakens them that

they produce no grain. Other minute gnats or midges

are destructive to clover in

the United States, either by

binding the leaves together

and sucking the sap of the

plant or by destroying the

young seed.

The mosquitoes, or Culicidse,1

are so well known that it is

hardly necessary to describe

them. They can always be F -

identified by the feathery an-
tennae, by the presence of a

fringe of hairs on the hind margin of the wing, and by the

fact that the marginal vein runs all around the periphery of

the wing. The larvae are
usually aquatic, but some
species which are abun-
dant on our Western arid
plains must breed in the
earth. The eggs of the
aquatic species are laid in
a boat-shaped mass, which
floats on the surface of the

— Cecidomyia, the Hessian-
fly. <i, larva; b, pupa. From
the '• Standard Natural History."

FIG. 71.— Culex, the mosquito. A, larva;
c, its respiratory tube. B, pupa; cl, the
respiratory tubes; a, the end of the

niing appendages, dorsal view. After
drawing of E. Burgess.

water. The larvae escape

abdomen with the two oar-like swim- from the lower ends of the

egg-cases, and are known
as "wi skiers." The larvse

o o

rest vertically near the surface of the water, head downward,
with the tail end' of the body at the surface of the water,
1 Culex was Pliny's name for the fly.

ZOOLOGY

since respiration takes place at that end (Fig. 71, A, <?).
Upon emerging from the water, the mosquito floats in its
pupal skin until its legs and wings harden. Since a dis-
turbance in the water at this time would jeopardize the
life of the mosquito, this insect always breeds in quiet
waters. From the habits of the larvre, it follows that they
can be easily killed while in the pond by pouring kerosene
oil on the water, for this forms a film on the surface and

FKJ. Tl. — A crane-fly. Nat. size. Photo, by W. H. C. P.

prevents respiration. The objection to this treatment, how-
ever, is that most of the other aquatic organisms also are
killed by it.

The crane-flies (Tipulidse1) look like mosquitoes, but can
easily be distinguished from them by the fact that they
have a V-shaped suture on the back of the thorax.
They are larger, and have relatively longer legs than the

1 tipula, among the Latins an insect which courses rapidly on the
water, — a water-spider.

THE FLY ASD ITS ALLIES 71

mosquito. Their legs are easily broken, and seem to be so
much in the way that flight is clumsy. The adults are
quite harmless, but some of the larvae are destructive in
that they feed upon tender plants and cause them to wither
and die.

There remain to be considered a number of degenerate
flies-- degenerate because parasitic in the adult state. The
first family we may consider is that of the louse-flies,1 or
Hippoboscidae.2 These small insects have a firm proboscis
used for piercing, and stout legs. Only certain of the
genera develop wings, and some of these lose them after
they gain their hosts. They live, like lice, in the fur of
mammals or the feathers of birds. They are viviparous,
the larvae being ready to pupate at the time of birth. The
sheep-tick, Melophagus3 ovinusf is one of the best-known
forms. Diptera allied to the foregoing live as parasites
on the body of the honey-bee.

Fleas (Aphaniptera 5) are likewise wingless, blood-suck-
ing parasites. The body is laterally compressed so that it
can move easily among the hairs of its host. The hind-
ermost legs are strongest, and are used in springing. In
Europe the human flea, PulexQ irritans? is a common pest,
but in this country the dog or cat flea is the one which
causes most inconvenience to man. The dog flea differs
from Pulex irritant in having a row of tooth-like spines on
the lower margin of the head. The fleas develop in dust
in the cracks of the floor and about the sleeping-places of
domestic pets. They may be combated by means of clean-
liness and Persian insect powder.

1 Suborder Pupipara. 4 Relating to sheep (ow's).

2 I'TTTTOS, horse ; /Socr/cw, to feed. 5 d^ai/Tjs, invisible ; irrepov, wing.

3 (JLT)\OV, sheep (wool) ; ^(£70;, to eat. 6 Flea. 7 Irritating.

72 ZOOLOGY

Diptera affect man directly in very diverse ways.
House-flies, black-flies, mosquitoes, and fleas are a positive
source of discomfort, and often of disease. Thus there is a
minute round worm, Filar ia l hominis? allied to the vinegar
eel, which thrives as a parasite in the blood-vessels of men
living in the tropics. The existence of this parasite, it is
believed, depends upon the mosquito. The embryos are
found in the surface circulation only at night, during which
time man is most defenceless toward the mosquito. The
embryos of the Filaria which have been sucked out of the
blood by the mosquito develop in its alimentary tract, later
they are deposited in stagnant water with the eggs of the
mosquito, and reach man's body again if the water be
drunk by him.

It is a current scientific belief that house-flies, whose
larval stages are often spent in filth, which also the egg-
laying females visit, are an important agent in the distribu-
tion of disease. At least the suspicion is strong enough to
justify all care taken to exclude flies from contact with food.

Indirectly Diptera are injurious to man by attacking
domestic animals and cultivated plants. Thus the tsetse-
fly is a menace to the commerce of a large part of a conti-
nent. The horse-fly, the horn-fly, which worries cattle, the
buffalo-gnat, which worries or even kills domestic animals,
and the dangerous bot-fly, are all causes of great loss to
industry. Also we have seen that the larvae of some flies
infest vegetables, -- such as cabbage, radish, cauliflower,
onion,- -as well as various fruits, and cause great damage.
The gall-gnats destroy clover and its seed ; and, worst of
all, the Hessian-fly infests wheat and Indian corn. This
last-named scourge, so called because of a tradition that it

«D

1 filum, thread. 2 Of man.

THE FLY AND ITS ALLIES 73

was imported in the straw bedding of the troop-ships which
brought over the Hessian mercenaries in 1775, has spread,
within a century, over the eastern half of the United States,
and has at various times injured the wheat crop to the
value of millions of dollars. The larvae of certain Muscidse,
especially the genus Chlorops,1 attack, in Europe, the
stems, leaves, and ears of wheat, rye, and barley, and
cause in some years great destruction, especially in Scan-
dinavia.

Over against the injury wrought by the Diptera may be
placed certain benefits bestowed by them. In the first rank
come certain species which prey upon injurious insects,
either in the larval or adult stage. The robber-flies prey
on the Diptera, Hymenoptera, and certain beetles, but they
are not careful to choose alone injurious species. The
larvae of the Syrphidse prey on the injurious plant-lice;
those of horse-flies are carnivorous, and feed on insect larvae.
The larvae of certain small flies are internal parasites of
bugs, beetles, and other (mostly injurious) insects ; while
those of various other Diptera are useful in acting as scav-
engers, — mosquito larvae, for example, serve in this way.
The carrion-fly devours putrid animal substances, which
might otherwise be a source of discomfort or disease. The
insects which feed on decaying vegetable matter are also
not to be despised. Finally, the larvae of some crane-flies,
robber-flies, and Syrphidse, by boring into rotten wood,
help in the work of forming forest mould. The Diptera,
like almost every other insect group, has its economically
injurious and beneficial species, and it is impossible to say
whether mankind would be better or worse off were the
group to be exterminated.

green ; cfy, eye.

CHAPTER V

LITHOBIUS AND ITS ALLIES

LITHOBIUS is a representative of the group Myriapoda,1
which are air-breathing, wingless Arthropods, closely allied
to insects.2 In the body only two regions, head and trunk,
can be distinguished ; the head bears one pair of antennae,
a pair of jaws, and one or two pairs of maxilhe. Every
segment bears legs. Myriapods differ from insects, then, in
that they have no legless abdomen.

Myriapods fall into two principal groups,- -Chilopoda3
and Diplopoda.4

The chilopods, or centipedes, to which group Lithobius
belongs, are active and ferocious myriapods. They are
especiall}r abundant in tropical countries, but thrive also in
elevated, cold situations, and at least one species inhabits
the caves of North America. All are terrestrial, and live
in damp and dark places, especially under stones and
bark, within or under decaying wood, among barn-yard
refuse, in loose soil, and under fallen leaves. Chilopods
feed upon living insects, mollusks, and worms, and may be
useful to agriculture through the destruction of injurious

s, very many ; TTOVS, foot.

2 Keys to the principal families of the Myriapoda, and to the commoner
species of Lithobius, will be found at the end of the Chapter, page 78.

3 More correctly Cheilopoda, from xe^°s, lip< and TTOVS, foot; because
the mouth parts (modified feet) are partially united to form a sort of lip.

4 diTrXous, double ; TTOVS, foot ; having two pairs of feet to the segment.

LITHOBIUS AND ITS ALLIKS

insects. Lithobins has been observed to spend hours in
killing an earthworm, whose juices it sucked as food.
Blue-bottle flies also serve it as food while in confinement.

Lithobius1 is of world-wide

distribution, and

over one hun-

dred species are

recognized. Our

common straw-

colored, eastern

species, Litho-

bius forficatusf

is found also in

South America,

as well as over

most of Europe.

It seems to be

replaced south

of Virginia by

another species,

spinipes.

Scutigera 3 is

easily distin-

guished by its

J
loilg legs ; its

hind legs, in-

deed, are longer

than its trunk.4 Our common Eastern species (rare
of New York City) is about 25 centimetres long,
of a light brown color, with stripes on the back.

FIG. 73. — Scutigera. Nat. size.
From Wood.

FIG. 74. -
peiiclra.
size
Leunis.

- Scolo-

Nat.

Fro in

north

and is

It is

1 Xi'0os, stone ; jSiow. to live.

3 scutum, shield ; yerere, to bear.

2 Provided with shears, forfcx.

4 Fig. 73.

ZOOLOGY

very active, and feeds especially on spiders. It looks some-
thing like a spider itself when in rapid movement. The
Scutigeras are characteristic of the tropics, where they live
especially in cellars, crawling up horizontal walls.

Scolopendra 1 includes longer and stouter myriapods than
Lithobins.2 To this genus belong the poisonous centipedes
of tropical countries. Among these is the giant Scolo-
pendra of our Southern States, South America, and the
West Indies, which reaches a length of 25 centimetres
or more. This animal has a poisonous bite, which is
fatal to insects and other small animals, and causes pain-
ful and even dangerous wounds upon man. The biting
apparatus is the first pair of feet, modified to form sharp
hooks, and provided with poison-glands,
which open near the apex of the claw. Ac-
cording to Humboldt, the Indian children of
South America tear off the heads of large
centipedes and eat the remaining portions.

Geophilus3 includes relatively slow-moving
species, often attaining great length, having
up to two hundred segments to the trunk
(Fig. 75). The species are common in
Europe and America. They live mostly
under stones. There is a European species,
G-eopliUus electricus, which is phosphorescent,
FIG. 75.— Geo- shining in the dark like a glow-fly.
piriius mor- Julus 4 is very different in appearance from

uC£X» -IN £Lui

size. Photo. the preceding, for it has a cylindrical body

and numerous small legs nearly concealed

beneath it. It is commonly known as "galley-worm."

o-Ko\o7T€vdpa, myriapod of Aristotle.

Fig. 74.

3 777, the earth ; 0tXew, to love.

4 t'oiAos, centipede.

LITHOB1US AND ITS ALLIES

FJG. 76. — Jalnn ca/m-

The members of this genus crawl rather slowly, and
when at rest coil the body. When disturbed they give
out a strong odor through lateral open-
ings of the body. They feed on dead
snails and earthworms ; some species,
on ears of Indian corn or strawberries.
Their eggs are laid in holes in the
ground in the spring ; consequently densis. Nat. size.
they may be easily dug up at this Phot0' by W-H-C-P-
season. One of the common Eastern species of North
America is Julus {Parajulus) canadensis, which is dark
brown or black above, has sides spotted with yellow, and
nearly colorless feet, and is about 20 to 25 millimetres

long (Fig. 76). Spirobolus is a large
species, 10 to 12 centimetres long.

Polydesmus l includes much-flattened
species, which, when disturbed, roll up
spirally. P. canadensis, of the northern
United States, is deep brown, with
pubescent antennae. These myriapods
are somewhat destructive to agricul-
ture, especially to cabbage and straw-
berries.

Two genera of myriapods which
stand somewhat isolated deserve a

FIG. 77. - - Polydesmus . , , . . ,

canadensis (=P.serra- passing notice. Pauropus * and allied

t-us). <i.5. Photo, by genera include a few animals about
w. H. c. P.

1 millimetre long, found on the moist

loam of woods. They are intermediate between chilopods
and diplopods, inasmuch as they have only one pair of legs

TroXus, much ; Secr/zos, band.
2 TraO/oos, small ; TTOUS, foot,

ZOOLOGY

to a segment and only one pair of maxillae. P. huxleyi
occurs both in Europe and in the United States (vicinity
of Boston and Philadelphia). Scolopenclrella l is a small,
white species, having very large -antennae and a pair of
backward-directed stylets. The mouth parts are very much
like those of the lowest insects, so that Scolopenclrella
bridges the gap between myriapods and true insects.

APPENDIX TO CHAPTER V

KEY TO THE PRINCIPAL FAMILIES OF THE MYRIAPODA

«i. Not more than 1 pair of feet to the segment ;
much segmented antennae ; 2 pairs of maxillae
[Chilopoda].

1 1. With facetted eyes ; 8 dorsal plates ; long
legs . ....

1.2. "No facetted eyes, but single or aggregated

simple eyes ; 15 or more dorsal plates.
Ci. 15 pairs of legs ; antennae at least ^ as
long as body ; body usually with
more than 20 segments

Ci. More than 21 pairs of legs.

f?i. 21 to 23 pairs of legs ; antennae
more than 14-jointed

d>. Never less than 30 pairs of legs ;
antennae 14-jointed .

Most of the segments with 2 pairs of legs ; an-
tennae with 5 to 8 segments ; 1 pair of maxillae
[Diplopoda].

l>\. Anus in penultimate segment ; body covered
with bunches of hairs ....

1 Diminutive of Scolopendra.

Scutigeridce

(Ex. Scutigera)

Lithobiidce

(Ex. Lithobius)

Scolopemlridw

(Ex. Scolopemlni)

Greophilidce

(Ex. Geophilus)

Polyxenidce.

APPENDIX TO CHAP TEE V 70

Anus in ultimate segment ; body without

bunches of hairs,
d. Mandibles not rudimentary ; mouth

parts not suctorial.
d\. Segments 80 or more.

e\. Anal segment produced into

a spine .... Julidce

(Ex. Julus)

e2. Anal segments produced into
2 slender papilhe, or uni-
dentate .... Craspedosomidce
d-2. Segments 19 or 20 ... Polydesmidce

(Ex. Polydesmus)
Co. Mandibles rudimentary, mouth parts

reduced Polyzoniidw

KEY TO COMMONER SPECIES OF THE GENUS LITHOBIUS

a\. Posterior angles of none of dorsal plates pro-
duced ; pores on coxae uniseriate.
b\. Anal feet armed with 1 spine ; posterior coxae
unarmed ; spines of first pair of feet, 2, 2,
2-2, 3, 2 (Central States) . . . bilabiatits

b-2. Anal feet armed with 3 spines ; coxse with
indistinct spine ; spines of first pair feet,
2, 3, 2 (Central States) .... cardinalis

«2. Posterior angle of the 9, 11, 13 dorsal plates pro-
duced ; antennae, 33-43 joints (eastern U.S.) forficatus
«3. Posterior angle of the 7, 9, 11, 13 dorsal plates
produced ; 31-38 joints of antennae (southern
U.S.) . . . . . . . . spinipes

«4. Posterior angle of the 6, 7, 9, 11, 13 dorsal plates
produced ; joints of antennae, 14.-23 (eastern
U.S.) multidentatus

CHAPTER VI

THE SPIDER AND ITS ALLIES

SPIDERS constitute a well-defined group called Araneina,1
characterized by an unsegmented cephalothorax and abdo-
men, of which the latter is stalked, and bears spinning
tubercles or spinnerets upon its hinder end. Antennae
are absent. The first pair of mouth appendages are called
chelicerse and end in claws, at whose apices the poison-
glands open to the exterior. The second pair of mouth
parts, called pedipalps, are long, and seem to take the
place of antennae. Near the stalk of the abdomen on the
ventral side is a pair of slits which open into two lung
sacks (hence Dipneumones). In a few spiders there is a
second pair of slits; these spiders have four lung sacs
(hence Tetrapne union es).2

The best known of our spiders are the orb web-spinning
garden spiders, belonging chiefly to the genera Epiera3
or Argiope 4 and the house cobweb spinning spider
Theridium.5

Argiope spins webs of very geometric form between
stems of weeds, Branches of shrubs, or along fences in
our meadows.6 Its web belongs to the full-orb type in

fa, spider.

2 A key to the seven subdivisions of the Araneina will be found at the
end of this Chapter, page 95.

3 e/uLireipos, skilful, experienced.

4 Name of a nymph. '° eypidiov, a little wild animal. 6 Fig. 78.

THE SPIDER AND ITS ALLIES

contrast to the condition in other orb-spinners, in which
a sector of the circle is omitted or in which a sector only
is formed. At the centre of the web of Argiope there is
an oval, closely woven shield of silk. The spider, when at
rest, is usually found upon or under this shield. Another
frequent character of the web is a zigzag ribbon, extending

FIG. 78. — Web of Argiope, placed horizontally over a fish-way.

by W. H. C. P.

Photo.

downward from the central shield, and sometimes upward
also, and attached to two or more radii. This zigzag,
which is doubtless the "winding1 stair' referred to in

the rhyme, " The Spider and the Fly," is formed, as Fig.
79 shows, by preventing the fusion of the strands as they
emerge from the spinnerets.

ZOOLOGY

The genus Theridium and its allied genera constitute the
most extensive family found in the United States. The
spiders belonging to the family are small, with relatively
large, rounded abdomens. They have eight eyes, arranged
in the manner shown in the diagram, Fig. 80. Their webs

show no attempt at
geometric arrangement,
such as is seen in the
web of Argiope and
other orb-weavers, but
the threads cross in
every direction, forming
a sort of intricate trestle-
work. The species
Theridium tepidario ni ui
is the common little
cobweb-spinner of our
houses and barns ; it also
spins about fences. Its
color varies from a livid
white to a livid brown
or plumbeous color. In
the south this species

FIG. <9. — Argiope spinning the "winding
stair." The numbers 1, 2, 3, 4, indicate IS much preyed upon

points successively formed in the order of b mud-daubillff wasps
these numerals. From McCook. °

(Sphex1), which put

twenty to thirty of them in each cell of the nest as
food for the young. Probably this enemy is one of the
causes that has driven this species to the homes of man.

Food. — Both Argiope and Theridium feed upon insects.
Flies, bees, grasshoppers, etc., are caught in the web and

wasp.

THE SPIDER AND ITS ALLIES 83

bound up, either for immediate or future consumption. A
few authentic instances have been recorded of the capture
of mice by ordinary spiders, and some tropical 0 0 0 0
spiders are said to capture occasionally small 0 0
birds within their webs. All spiders eat FIG. so. — Dia-

, , ,. ., 1-1 gram of posi-

voraciously, and ordinarily drink a great tkmof eyes in
deal of water; yet they may survive, in Theridium.

J The four cen-

tne absence 01 rood ana water, tor many trai eyes are

months. the largest.

Distribution. — Argiope occurs over all of North America.
A. cophinaria, the basket Argiope, is the large black and
yellow spider well known to all frequenters of Melds. It
occurs from Massachusetts to Texas, and west to the Pacific
coast. A. argent at a, distinguished by the serrated form of
the abdomen, is found in the Southern States, the West
Indies, and northern South America. Theridium occurs
all over the world. T. tepidariorum is found, outside of the
United States, in South America, Europe, and Australia.
Twelve other species of this genus are found in New
England alone. Some of these spin webs in trees or
bushes, others in stone walls or among rocks.

Spinning Habits. - - Spiders spin for a variety of purposes.
Cocoons are made of silk, for the protection of eggs ; under-
ground nests, like that of the trap-door spider, are lined
with silk ; and, especially, nets are made of it to ensnare
insects. The silky threads may serve also to suspend the
spider while it drops from a tree, or they may, by their
friction with the air, serve to suspend certain spiders in
aerial migrations.1 This latter use is especially noteworthy.

1 The ballooning habit of spiders has been noticed since early times,
but it was formerly misinterpreted. Thus Pliny speaks of wool being
rained. The poet Spenser wrote : —

ZOOLOGY

A small spider, when desirous of taking flight, climbs up
some high object, such as a fence post, elevates the spin-
nerets, and spins loose silk into the air (Fig. 81). After
enough of it has been thus formed, the spider lets go, and
is supported by the currents in the air while it is wafted
great distances. Thus Darwin, on his voyage in the
Beagle, saw cobwebs bearing up spiders floating in the

air over his vessel more than
sixty miles from shore.

The method of spinning
deserves careful attention.
The spinning-organs consist
of a set of glands lying in the
hinder part of the abdomen,
and opening to the exterior
through a number — - often
several hundred --of spin-
ning "spools." These spools
are the modified mouths of
glands, and are grouped
upon and between tubercles
called spinnerets. The
secretions of the glands, as
they are poured out into
the air, fuse together and

harden into a thread. The thickness of the thread is
determined by the number of glands secreting together.

" More subtle web Arachne cannot spin ;
Nor the fine nets, which oft we woven see,
Of scorched dew, do not in th' ayre more lightly flee."

Thompson writes : —

" How still the breeze ! save what the filmy threads
Of dew evaporate brushes from the plain."

THE SPIDKU AND ITS ALLIED

Classification. - -Spiders are separated, according as they
spin webs or do not do so, into two main groups, sedentary
and wandering spiders. The sedentary spiders are sub-
divided into four sub-orders, which we shall consider in
turn : —

FIG. 82. — Mygale, a Tunnel-weaver, allied to the " trap-door spider."

Nat. size. From Emerton.

1. Tunnel- weavers (Territelarite 1). These spiders make
tubes in the earth, and line them with silk. The repre-
sentatives of this group in the Southwestern States are

1 terra, earth ; tela, tissue or web.

ZOOLOGY

commonly known as trap-door spiders. The lid of the
nest is covered with hardened dirt, and when closed, looks

exactly like the ground around

FG it. Some of these spiders gain

a great size and capture birds
(Fig. 82).

2. Orb-weavers (Orbite-
lariee 1). These, which are
typically represented by
Argiope, are well known ; yet
few persons have studied the
almost mathematical precision
with which the webs are built.
Foundation lines (Fig. 83)
of unusual strength are first
laid down, to form the periph-
ery or frame of the web. Then
radii are spun from a central
little ball of floss to the frame. The radii are, often at
least, laid down alternately on opposite sides of the
centre. The number of radii formed by a species of
spider is not perfectly constant, but varies within limits.
It would be an interesting occupation to sketch a number
of webs of Argiope showing the variations in the number
of radii and the other details of form. After the radii are
placed, the spiral lines are laid down. In the completed
web four regions are distinguishable, as follows, passing
from the centre outward : (1) the notched zone, consist-
ing of four to eight turns of a spiral at the centre ; (2)
the free zone in which no spiral is laid down ; (3) the
spiral space, the main part of the spiral framework ; (4) the

1 orbis, circle ; tela, web.

FIG. 83. — Diagram on nomencla-
ture of parts of an orb-web. FS,
foundation space ; SS, spiral
space; CS, central space ; FZ,
free zone ; NZ, notched zone ; H,
centre. From McCook.

THE SPIDER AXD ITS ALLIES

foundation space, without the spiral lines, and at the outer
margin of the web. No study is more interesting than
that of the details of construction of these parts of the
spider web, while they are being made out of doors or in
large glass jars.

FIG. 84. — Orb-web of Epeira. a, first spiral line ; b, second spiral line ; c, line

to nest. From Emerton.

3. Line-weavers (Retitelarise1).- -Of this group The-
ridium is a type. The web consists of a fine irregular mesh
with strands running above and below in various direc-
tions.2 The spider stands below the main part of the net,
back downward.

1 rete, net ; tela, web. 2 Fig. 85.

ZOOLOGY

4. Tube- weavers (Tubitelarue 1). Here belong the
spiders that spin webs in the grass, which are so conspicuous
in the morning when laden with dew (Fig. 86). At one
side of the web a tube leads down among the grass stems.
At the opening of this tube the spider stands ready to

FIG. 85. —Web of Theridium, a " cobweb." From Emerton.

dart out after prey, or to retreat as occasion demands
(Fig. 87).

The wandering spiders do not spin webs of any kind.
They are classified into three groups as follows : —

1 tubus, tube ; tela, web.

THE 8PIDER AND ITS ALLIES

(1) Crab spiders (Laterigradse *) are so called because
they run sideways. They make nests by fastening together
leaves by threads of silk. Their young are reared in these
nests, and watched over by the mother (Fig. 88).

('2) Running spiders (Citigradre2). - These are for the
most part large and powerful species which wander over

FIG. 86. — Web of a tube-weaver; looking down upon the web, which is in a
corner between two vertical walls. The tube is in the angle. Photo, by
W. H. C. P.

fields or along watercourses in search of prey. Our
Northern species belong chiefly to the genus Lycosa3 (Fig.
89). They live in holes in the ground, making a ring of
silk at the orifice. The female carries her eggs about in
a special cocoon attached to the end of the abdomen. The

j side ; gradus, locomotion. 2 citus, rapid, + yradus.

3 Xtkoj, wolf.

ZOOLOGY

FIG. 87. — Agalena, the common
grass spider. Nat. size. Photo,
by W. H. C. P.

young are borne on the back of
the mother. The great size,
black color, and hairiness of
some of these spiders have given
them an apparently unjustified
reputation of being very poison-
ous. Naturalists who have al-
lowed these spiders to bite the
hand report that the bite is rarely
more poisonous than that of the
mosquito.

(3) Jumping spiders (Salti-
gradse 1). - This family includes
many familiar, active species of

high intelligence. Some of these of grayish color live in
houses, and are recognized
as members of this family
by their half -running, half-
jumping gait (Fig. 90).
The cocoon is attached to
some object and enclosed
in a sort of tent, in which
the mother also lives to
guard the young.

The economic impor-
tance of spider webs is con-
siderable. First of all,
they are of the greatest
importance in capturing
many destructive insects,
such as flies, mosquitoes,
and moths. Another use

1 saltus, jumping, + yradus.

o
o

O O

o o

FIG. 88. — Thomisus, a crab spider. Dia-
gram showing arrangement of eyes at
bottom of figure.

From Emertou.

THE SPIDER AND ITS ALLIES

to which they have been put is in making silk cloth. The
silk of the spider is smoother and glossier than that of the
silk-worm, but it is much harder to collect in quantity.
A spool is passed against the spinnerets of an individual
spider and slowly revolved, winding the silk upon it.
The difficulty comes in rearing the spiders, for they are
extremely voracious and if the supply of flies is insufficient

FIG. 89. — Lycosa, a running spicier.
Ocelli formula below. From Emer-
ton.

FIG. 90. — Attus, a jumping spider.
From Emerton.

they attack and devour one another. Consequently they
must be kept isolated and fed individually, and yet yield
in the end only an ounce or so (about 30 grammes) of
silk. Other uses of spiders' silk are : in the construction
of cross-hairs in telescopes, and in medicine as a narcotic
in case of fevers, - - a temporary fad.

Poisonous Spiders. — Spiders are feared by many people
from a belief that they are very poisonous, even fatally so.
Spiders have, indeed, biting jaws provided with poison-

92 ZOOLOGY

glands, and their bite is often fatal to insects, and even to
small birds and mammals. But most spiders cannot spread
the chelicene sufficiently to make a bite in the human skin,
and even the largest forms seem to inflict but a slight
wound, scarcely ever greater than that of a mosquito.
The stories of the severe effects of the bite of the Taran-
tula, one of the Lycosidse, are entirely fabulous.

Spiders show a marked sexual dimorphism. Particularly
among the orb-weavers the males are much smaller than
the females of the same species, but the legs of the male
are relatively the longer and stronger. The male is usually
shorter lived than the female, for the latter has often to
watch the egg-cocoons, or carry them about with her until
the young hatch out. The male also builds less perfect
webs than the female. The relation existing between
mated pairs is often peculiar. The male is frequently
killed and eaten by the female; but if the male can over-
come the female, she may fall his victim. Among wander-
ing spiders there is often a selection by the female from
among several rivals, which engage in severe battles with
each other.

Allies of the spider must be briefly mentioned. The
spider belongs to the class Arachnoidea,1 characterized as
follows : Air-breathing, wingless arthropods, whose head
and thorax are usually united to form a cephalothorax,
which bears two pairs of jaws and four pairs of legs ; the ab-
domen, which is not always separated from the cephalo-
thorax, possesses no legs. The principal subdivisions of
the Arachnoidea are as follows : -

The Arthrogastra,2 including the scorpions and their
allies, are characterized by the fact that the abdomen is

j, spider ; eUos, form. - dpdpov, joint ; yarnf/p, abdomen.

THE SPIDER AND ITS ALLIES

palp.

segmented and intimately joined with the cephalothorax.1
Here belong the true scorpions, in which the posterior six
segments of the abdomen are much smaller in diameter
than the seven anterior segments, and form a sort of tail
(post-abdomen ) . Nearly
twenty species of scor-
pions occur in the
warmer parts of North
America. Centrums in-
famatus ranges from the

* O

southern Atlantic States,
through Texas, and
north into southern Kan-
sas. The tip of the tail
bears a sting, which con-
nects with a poison-sac.
The largest scorpions
of the tropical countries
are the most dangerous,
but the wounds even of
these are rarely fatal.

The Phalangina,2 the
extremely common
"Daddy-long-legs," or
harvest-men, in which

the legs are very long, FlG oi.__Buthus, a European scorpion.

and the abdomen short Dorsal view. MX., maxillary; Cephth.,

, . . , rp. cephalothorax; Troch., trochanter ; Tor.s'.,

and tlllCK. hey OCCUr tarsus; AbO., abdomen ; Bla., poison blad-

aboilt houses, in woods, der; St., sting. From Kraepelin in "Das

Tierreich.'

and in fields. They

feed on small insects and are highly beneficial animals to

2 0aAd77ioj>, a spider, especially a poisonous species.

Dorsal ridge*---
Lateral ridge-'

1 Fig. 91.

ZOOLOGY

FIG. 92. — Liobunum dorsatum, one of the harvestmen. The long legs are
apt to be thrown off in handling the living animal. The second left leg is
accordingly absent in this specimen. Nat. size. Photo, by W. H. C. P.

FIG. 93. — Psoroptes, the sheep scab, female.

Right

figure, dorsal view; left

figure, ventral.
Industry.

Much enlarged. After Salmon, Bulletin 21, Bureau Animal

THE SPIDER AND ITS ALLIES 95

man. Liolmnum dorsatum is a common grayish species
with a darker dorsal band, which emits a clear fluid when
handled (Fig. 92).

The Areneina, or spiders, already considered.

The Acarina,1 or mites and ticks, in which, as in spiders,
the abdomen is unsegmented, but is fused with the cephalo-
thorax. Mites have typically a round body. They exhibit
great diversity of form and habits. All are
terrestrial, excepting one group of aquatic
mites, and are often of a bright red color
(A tax). The free-living species prey on
smaller animals, as well as dead organic
substances. Others are parasitic in animals

, . . • f p J.T 9 i FIG. 94. — Pal-

or plants, living in fur or leathers/ and even Ien6) a sea_
penetrating into the skin, as the small red spider. : 1.5.

,, , . ,, r. 0 ,, Photo, living

"jigger or " c nigger ' or our bouthern byW.H.c. P.
States does.

Finally, there lives in the sea an aberrant family of
spiders which crawl on the sea-bottom or over hydroids,
and thus have forsaken a terrestrial life for a completely
aquatic one (Fig. 94).

APPENDIX TO CHAPTER VI

KEY TO THE SEVEN SUBORDERS OF THE ARANEIISTA

«i. With 4 slits into lung sac [Tetrapneumones]. Che-
lifer claw directed downward ; 8 closely grouped

eyes Territelar!«'

(Tunnel-weavers)

a*. 2 slits into lung sac [Dipneum ones]. Chelifer claw
directed inward.

i a/cct/n, mite. 2 Fig. 93.

ZOOLOGY

b\. Eyes in 2 transverse rows ; most species spin

webs [Sedentarise].
Ci. Legs not spread flat out.

d\. Spinnerets short and inclined together,
and on under side of abdomen, which
is usually round.

e\. Anterior row of eyes near margin
of head

e-2. Anterior row of eyes remote from
, margin of head ....

d\. Spinnerets at end of abdomen, which
is elongated .....

Ci . Legs spread flat out .....

61. Eyes in 3 transverse rows ; spin no webs, but

hunt prey [Vagabundse].
Ci. Anterior eyes smallest ....

c2. The anterior eyes largest .

OrbitelaricB

(Orb-weavers)

Retiielarice

(Line-weavers)

Tubitelarice

(Tube-weavers)

Laterigradce

(Crab spiders)

CitigraddB

(Running spiders)

Saltigradce

(Jumping spiders)

CHAPTER VII

THE CRAYFISH AND ITS ALLIES

THE crayfish belongs to the class of Crustacea, since it
breathes by means of gills, possesses two pairs of antennae,
a pair of mandibles bearing palps, and a pair of append-
ages on all body segments excepting the last. The
Crustacea are divided into two subclasses,- - Entomostraca,
of which Daphnia is an example, and Malacostraca, to
which the crayfish belongs. All the Malacostraca 1 have
19 pairs of appendages.2

The crayfish,3 which is closely related to the marine
lobster,4 is an inhabitant of fresh-water lakes, rivers, and
pools. It thrives in diverse surroundings; for some species
prefer cool mountain streams and others muddy pools,
while certain species, both in Europe and America, are
found in brackish as well as fresh water. Indeed, the
European Astacus fluviatilus is said to be frequently

s, soft ; 'ocrrpaKov, shell (since the shell is less hard than that
of mollusks).

2 Keys to the six chief orders of Malacostraca and to families of the
stalk-eyed Crustacea will be found in the Appendix to this Chapter, p. 122.

3 The old English spelling of this word was ''crevis'' or "crevice."
The ere came to be spelled phonetically cm//, while vis became
changed to fisli in accordance with the popular nomenclature of all
aquatic animals.

4 The English word " lobster " is from the old English lopystre, which is
probably corrupted from the Latin locusta, by which term Pliny refers to
the lobster.

H 97

98 ZOOLOGY

caught off the Livoniaii coast, even some distance out at
sea. Individuals of an American species have been taken
from a mineral spring impregnated with sulphur and
magnesia at a temperature of 70° Fahr. (21° Cent.),
while several kinds of the American "burrowing' or
" chimney "-forming species have been found in meadows
and clay bottoms, often at great distances from streams.
Certain species that are blind inhabit caves only. In
England, according to Huxley, "in granite districts, and
others in which the soil yields little or no calcareous

matters to the water which flows over it, crayfishes do not
occur. They are intolerant of great heat or of much sun-
shine ; hence they are most abundant in those parts of
rivers which flow east and west, and thus yield the most
shade from the midday sun."

The food of the crayfish is very varied ; it may be living
or dead, animal or plant. On account of the need of
calcareous matters in the food, crayfishes are especially
fond of the stoneworts (Chara) and various succulent
roots, like the carrot. It is said that crayfishes sometimes
make excursions inland in search of plant food. They
likewise devour shells of snails, their own cast-off skins,
and occasionally each other, shell and all.

There are two great groups or subfamilies of cray-
fishes. One, restricted to the Northern Hemisphere, is
found in Europe, Asia, and North America. The other is
found in the Southern Hemisphere, in Australia, Tasmania,
New Zealand, Fiji Islands, Madagascar, and South America.
No crayfishes have been found on the continent of Africa,
or in the rivers of northern Asia that flow into the
Arctic Ocean, or in those of southern Asia. These Asiatic
rivers are populated by fluviatile crabs, to which the cray-

THE cnAYFixrr AND ITS ALLIES 99

fishes of the region have probably succumbed. All the
islands now inhabited by crayfishes, such as England.
Japan, and Cuba,1 were probably once connected with the
mainland.

The northern subfamily of crayfishes contains, accord-
ing to Faxon, two genera- -Astacus and Cambarus- -of
which the latter can be subdivided into the subgenera
Cambarus and Cambaroides. These groups occupy dis-
tinct geographical areas. The genus Astacus is found, in
the Old World, in Europe and western Asia as far south
as the Aral and Caspian seas, and in America in the region
west of the Rocky Mountains, draining into the Great Salt
Lake and the Pacific Ocean. It is thus seen to occupy the
western sides of the two northern continents. Likewise
Cambarus and Cambaroides occupy the two eastern coasts
of the northern continents; for Cambarus is found in North
America east of the Rocky Mountains in the region
bounded on the north by Lake Winnipeg and New Bruns-
wick and on the south by Guatemala and Cuba, while
Cambaroides is limited to the Amoor River basin in Asia,
and to Japan.

We thus find among the crayfishes what is known as
discontinuous genera; that is, genera which now occupy
widely separated areas, such as Astacus in Europe and
Pacific North America, but which once ranged over the
intervening regions as well. From some cause, the
struggle for existence became too severe in the intervening
regions, so that Astacus and Cambarus were annihilated on
the eastern and western sides of the continents respectively.
In southern Asia we find that the struggle was doubtless
with the successful river-crab. It is interesting to note

1 It is doubtful whether Cuba has been connected with the mainland.

100 ZOOLOGY

that, probably on account of the preserving influence of
climate, the other animals and the plants of the eastern
sides of the two continents and those of the western sides
are more alike than those from opposite sides of the same
continent. One of the best pieces of evidence for the con-
clusion of a former hemispherical distribution of the two
genera of crayfishes is that there occur in the caves of
Carniola in southern Austria crayfishes l belonging to the
genus Cambarus - - the only known living representatives
of this type in Europe. The mere fact that it lives in a
cave is not sufficient to make the Carniola crayfish a Cam-
barus, for in North America the genus has certainly not
originated under the influence of subterranean life ; it is
more likely that the caves of Carniola have protected these
crayfish from the widespread destruction which has over-
whelmed their fellows outside.

Only one crayfish, Cambarus Bartonii, is found in New England.,
and here, with two or three local exceptions, only in the rivers of
Maine. This C. Bartonii has the widest geographical distribution of
all the northern species. C. Blanding'd is the most widely distributed
of the southern species. C. pellucides is the blind species found in
Mammoth and Wyandotte caves.

The lobster (Homarus) is, as we have already seen, the
nearest living salt-water relative of the crayfish. There
are only two species of the genus Homarus. One, Homarus
americanus, occurs on our Atlantic coast, the other,
H. vulyaris, is the lobster of Europe. On our Pacific
coast there is the "spiny lobster," but this is not closely
related to the eastern lobster (Fig. 95). The national gov-

1 These crayfishes are blind, like the cave-inhabiting Cambarus of
America.

THE CRAYFISH AND ITS ALLIES

101

eminent has transplanted the Atlantic lobster to several
localities on the Pacific coast, but it is not yet known
whether it will thrive there. The American lobster ranges
from Labrador to Delaware Bay, and from near shore to a

FIG. 95. — Palinurus, the spiny lobster. One-fourth nat . size. From Rathbun ;

drawn by H. L. Todd.

depth of 100 fathoms. It attains its greatest size on the
rocky shores in the cooler waters from Maine to Labrador.
It migrates but little along the coast ; in the fall, however,
it moves out into deep water, and in the spring back again

102 ZOOLOGY

into the shallower bays ; the time of migration depending
upon the length of the season. It is said to be a nocturnal
animal, searching most actively for its food at night. The
sense which probably aids it most in this search is that of
smell, as the attraction of the bait in the traps - - the so-
called lobster-pots — testifies. In respect to food it is, like
the crayfish, omnivorous.

Protection of the Lobster. — There has been much differ-
ence of opinion in regard to the size at which a lobster
becomes mature and before which, therefore, it cannot be
caught without danger of extermination. The legislation
on the matter has accordingly been very varied. In Con-
necticut the law makes the limit six inches, while in
Massachusetts and New York it is placed at ten and one-
half inches. Herrick has carefully investigated the relation
of length to maturity, and concludes that, on the Massa-
chusetts coast at least, the lobster becomes mature between
the limits of eight and twelve inches, and hence that all
present legislative protection is insufficient. The increasing
rarity of large lobsters in our markets testifies to the
correctness of this conclusion.

Enemies of the Lobster. — Besides its worst enemy, man,
both the adult (particularly the egg-bearing female, called
by fishermen the " berry lobster," or "berry hen") and
young lobsters are attacked by many kinds of fish. Two
or three internal parasites are known to infest the lobster,
while sometimes it is greatly hampered in its movements
by the number of messmates it; carries about attached to its
shell. Barnacles, mussels, tube-forming worms, and various
seaweeds are all found at times attached to the shell of the
lobster. Upon moulting, however, the animal is enabled to
rid itself of all these hangers-on ; but this very process of

THE ('HAY FISH AND ITS ALLIES 103

moulting, or casting off the entire shell at intervals, is
attended with great dangers to the lobster, since the animal
is so soft bodied as to be able to offer little resistance to
its enemies.

The moulting process in the lobster, crayfish, and other
Crustacea is made necessary from the fact that these animals
are enclosed in a chitinous covering which is impregnated
with salts of lime. It is evident that an animal cannot
increase in size while so encased ; hence special provision
for growth has to be made by the moulting or casting off
of the hard shell. This process is accomplished in the
following manner: previous to the throwing off of the old
skin a new soft one is formed inside, the lime is absorbed
from the old shell in a dorsal line along the carapace,
reaching from the rostrum to its posterior margin. Ab-
sorption also takes place at the joints of the limbs. AVhen
the lobster has attained this stage it is dark in color, and
known by fishermen as the " black lobster." The carapace
now splits along this dorsal median line of absorption, the
blood leaves the limbs, which are thus made flabbier, and
by involuntary muscular movements they are drawn, large
claw and all, through the joints of the old shell. The
anterior portion of the body is first drawn out through the
dorsal rent, and lastly the tail. Not only is the entire outer
covering cast off, but the lining of the oesophagus, stomach,
and intestine as well, since these organs are formed by an
infolding of the skin. By means of the return of the blood
to the limbs and rapid absorption of water, the body of the
lobster soon swells to a size far beyond that of the old shell.
There remains in the stomach, after moulting, a calcareous
nodule which has long been known by the name of "crab's-
eyes." These " crab's-eyes ' were formerly much sought

104 ZOOLOGY

after and prized on account of their supposed medicinal
qualities. The function of these gastroliths or " craVs-
eyes ' was for a long time rather obscure. It is now
believed that during the time of absorption of lime from
the shell, previous to moulting, the blood becomes strongly
impregnated with lime. If all the lime that must be re-
moved were to remain in the blood, it would probably be
fatal to the animal ; hence it is taken up by secreting cells
located in the wall of the stomach, and there deposited.
After the old skin is cast, the gastrolith is soon absorbed,

FIG. 90. — Palasmonetes vulyaris, a common shrimp. Nat. sizo.

Photo. 'by W. H. C. P.

probably to aid in strengthening the new shell. Bits of
water-worn shells, entire gastropod shells, parts of lobster
coverings, spines of sea-urchins, etc., have been found in
the stomachs of lobsters and crayfish, which likewise would
probably have been dissolved and used in hardening the
shell.

Shrimps and prawns l belong to a thin-skinned, long-tailed
family of Crustacea.2 They are extremely common in bays

1 These are common names of small Crustacea applied chiefly to the
decapod family Carididse,* although also applied to certain Schizopods.
The term shrimp is applied to the smaller species, and prawns to the
larger. 2 Fig. 90.

* (capis, a small marine crustacean.

THE CRAYFISH AND ITS ALLIES 105

along our coast, and even penetrate into rivers. Two river
shrimps l are found in the United States east of the Missis-
sippi River. These Crustacea are able to maintain their
enormous numbers only by virtue of their great repro-
ductive capacity, necessitated by the circumstance that
they furnish almost the entire food supply for many kinds
of fishes and other foes. Even in the principal shrimping
grounds of the United States- -such as San Francisco and

FIG. 97. — Gebla affinis, right side. Two-thirds natural size.
' Photo, by W. H. C. P.

New Orleans — there is said to be no diminution in the
numbers of shrimps.

The Thalassinidae 2 include certain crayfish-like species
which live on our coast, burrowing in mud-flats, where
they live concealed during the day. On account of their
being of only medium size and difficult to obtain, they are
commonly little known. Our Eastern species are Grebia
affinis (Fig. 97) and Callianassa stimpsoui.

The hermit crabs (Pagurida33) occupy a position inter-
mediate between the long and short tailed Decapods in

1 Palwmon Ohionis and Pal eomonetes exilipes.

2 0a\d(Tcrivos, color of the sea. 3 irdyovpos, a kind of crab.

106

ZOOLOGY

respect to the length of their abdomen. The abdomen is
soft, and the animal protects it by inserting it within the
coiled shell of some gastropod. Moreover, the abdomen is
asymmetrical, being coiled to one side to correspond with
the shape of the borrowed house (Fig. 99). The abdominal
feet become degenerate, with the exception of the posterior
pair, which are modified into a hook-like process, by means
of which the crab maintains itself securely in the shell.

FIG. OS.

Eupagunis longicarpus. Two individuals in shells. Photo, while
alive by W. H. C. P.

When one shell becomes too small, it is abandoned for a
larger one. Numerous species of hermit-crabs occur on
our coast, ranging from the shore line to a depth of several
hundred fathoms. Eupagurus longicarpus is the little
active hermit found in almost any tide-pool from Massa-
chusetts Bay to the Gulf of Mexico. Hydroids, polyps,
sponges, often attach themselves to these borrowed shells
(Fig. 98) ; indeed, a Chinese hermit-crab always bears an
anemone on its large claw, with which it plugs up the
aperture when obliged to retreat within its shell. One of

THE CRAYFISH AX.D IT* ALLIED

10'

the East Indian hermit-crabs, the so-called palm-crab, feeds
upon cocoanuts, Avhich it opens by inserting its claws into
the eyes and then breaking the shell upon the rocks.

The Hippidae include certain oval animals, which bur-
row, like a mole, head first, in sandy beaches. The name
of our common eastern species, Hip pa J talpoides? indicates
this resemblance ('Fig. 100).

FIG. 99. — Eupayurus lonylcurpus removed
from shell, x' Ifc. Photo, by W. H. C. P.

FIG. 100. — Hippa
Nat. size. Photo, by
W. H. C. P.

The Brachyura are represented on our shores by three
principal families, which may be designated as triangular
crabs, arched crabs, and square crabs.

The spider-crabs, or sea-spiders, as they are sometimes
called, belong to the triangular crabs. As their name
implies, their legs are very long and slender.3 These crabs
frequent oyster-beds and sea-bottoms in general. When

1 From i'TTTTos, horse ; used by Aristotle as the name of a kind of crab.

2 Like talpa, the mole.

3 Fig. 101.

108

ZOOLOGY

seen stalking over such uneven surfaces, the advantage of
these stilt-like legs is at once evident. The surface of the
body of some species of spider-crabs is hairy, entangling
inorganic matter, while hydroids, barnacles, and algae attach
themselves to the shell. Libinia emarginata and dubia^
the former ranging from Maine south, and the latter from
Cape Cod to the Gulf of Mexico, are our two species which

FIG. Wl. — IJliitiin dubia. One-third nat. size. Photo, hy W. H. C. P.

undergo such concealment. The great Japanese spider-
crab is said to be the largest of all the Crustacea, some
individuals measuring, from tip to tip of the first pair of
legs, 18 to 20 feet.

The edible crab is a typical arched crab. It is so called
because the carapace is arched in front. The carapace is
also broader than long, and narrower behind than in front.

THE CRAYFISH AND ITS ALLIES

109

The legs of this family are short and broad, and in some
species the posterior pair is especially broad - - an adapta-
tion for swimming. These crabs
may be divided into two groups
— the burrowing crabs and swim-
ming crabs. To the burrowing
crabs belongs the genus Cancer
(Fig. 102), which includes the
edible crab of Europe, especially
prized in England, together with
several American species; while
our common edible, soft-shelled
or blue crab, Callinectes hastatus
(Fig. 103), and the beautiful "lady crab" (Fig. 104)
belong to the swimming group. Representatives of other
families of crabs are, however, eaten in various localities
and by various peoples. For example, our little Pinnotheres

FK;. 102. - - Panopeus sayi,
allied to Cancer. The mud-
crab. One-half nat. size.
Photo, by W.H.C.P.

FIG. 103. — Callinectes hastatus, blue crab. Reduced to one-third. Photo.

by W. H. C. P.

110

ZOOLOGY

ostreum (Fig. 105), found in the mantle chamber of the
oyster, is eaten by us together with the oyster or separately.

FIG. 104. — Platyonichus ocellatus, lady oral). Reduced to one-third.

Photo, by W. H. C. P.

The fiddler crabs are representative of the square crabs.
These are the familiar animals which crowd salt marshes
and run sideways to and from their burrows. One claw is

much larger than the other.
When the crab is disturbed,
the large claw is brandished
in a manner which has been
likened to the movements of
a riddle as one plays upon
it. Crelasimus pugnax is the
most abundant species, and
ranges from Cape Cod to the Gulf of Mexico. Together
with Cambarus it does much damage by burrowing in the
levees of the Mississippi River (Fig. 100).

FIG. 105. — Pinnotheres oxtreum. X 4
From Rathbui).

THE CRAYFISH AND ITS ALLIES

111

The economic im-
portance of the Deca-
poda may be inferred
from the fact that
the receipts for the
lobster alone, taken
and sold by United
States fishermen, is

Fie, 106. - Gelasimus pugnax. Nat. size. estimated for 1892
Fronto-dorsal view. Photo. l>y W. H. C. P.

at one million dollars. The yield
to Canadian fishermen was in ad-
dition worth half a million dollars.
From the United States Fish Com-
mission Bulletin for 1890-91 we
find that the bine-crab fisheries on
the Atlantic and Gnlf coasts re-
turned almost half a million dol-
lars, while the shrimp catch in the
same waters brought nearly a
quarter of a million dollars more.
The latter industry on the Cali-
fornia coast is much greater, for
the shrimp trade of San Francisco
Bay alone is valued at a quarter of
a million dollars yearly.

The remaining orders of Mala-
costraca maybe briefly mentioned.
The Stomatopoda1 include only

FIG. 107. — Squt/la empusa, the

Sqililla,2 the mantis shrimp, SO mantis shrimp. Dorsal aspect.

From Bigelow.

1 (rr6/xa, mouth ; TTOUS, foot.

2 <7/d\Aa, classic name for a marine crustacean.

112

ZOOLOGY

called because of a certain resemblance to the mantis
insect (Fig. 107). This animal is found on our east
coast, where it burrows in the sand. It is a little longer
than a crayfish. Being hard to catch, it is not much
used as food. The Cumacea include a few small marine
Crustacea, not ordinarily seen. They are of interest be-
cause of the reduced carapace which is transitional to the
condition found in
the lower Crustacea.
The Isopoda l include

FIG. 108. - - Oiiis'.-us, the
sow-bug. Dorsal view.
Nat. size. Photo, by
\V. H. C. P.

FIG. 10<». - • Talorchestia lonf/ieornis, the
beach flea. Nat. size. Photo, by W. H.
C. P.

the sow-bugs or wood-lice (Fig- 108), noteworthy for
forming the largest group of land Crustacea, and certain
marine and fresh-water groups. The Amphipoda2 are
exclusively aquatic creatures, found under decaying
vegetation on beaches of lakes or the sea (Fig. 109), and
crawling amidst marine hydroids. Being laterally com-
pressed, the Amphipods tend to lie on one side when at
rest.

1 tVos, equal ; TTOVS, foot.

2 d/x0i, both ; Trotfs, foot.

THE CRAYFISH AND IT 8 ALLIES 113

Edible Lobsters. — The American lobster, Homarus Ameri-
canus, differs little in appearance from the European lob-
ster, If. vulgaris. Formerly the American lobster attained
the greater size, but the excessive catches of our species in
the last few years are rapidly doing away with this differ-
ence. The so-called Norwegian lobster finds its way into
European markets, while on our California!! coast the so-
called spiny lobster or sea-crayfish takes the place of our
true Atlantic lobster, and, like the latter, is said to be in
danger of extermination on account of overfishiiief.

c5 O

Edible Crayfish. - The nearest fresh- water ally to the
lobster - - the crayfish — has not yet attained the pop-
ularity in our markets which it possesses in Europe,
particularly in" France. So much is the crayfish esteemed
in Paris that the enormous crayfish farms throughout
France are unable to supply that city, consequently cray-
fishes are imported in considerable quantities from Ger-
many. In America, it is our French population mainly
that makes a market for the crayfish. Astacus nu/res-
cens is the crayfish sold in San Francisco markets. ( )n
the Atlantic coast, New York and New Orleans are the
main centres of consumption. Cambarus affims, taken
from the Potomac River, is the crayfish found in the spring
in the New York markets. Later in the season this
market is supplied by C. virilis and immunis, which are
shipped from Montreal, Milwaukee, and other Western
cities.

Edible Crabs. --Of the crabs which reach our market

the most important is the blue crab. These crabs are

kept moored in floating boxes until they have moulted,

and then they are sent to market as soft-shelled crabs.

114

ZOOLOGY

The shore crabs, Cancer, are little eaten in the United
States.1

Edible Carididae. - The shrimps and prawns have within
recent years begun to appear in large numbers in the
Eastern markets. For many years the Pacific species

P J? :.*%<s

«*—. -- .M<s^ ^VfcJ* t£v *

£ — ;J£-t3&tral

£• " -* ' / *".. > X" : A A^ ^ .«£

\,:: lawv-

FIG. 110. — Lhniihts 2)o!i/i>Ji"iiiux, the king-crab or horseshoe-crab.

have been dried and shipped by the Chinese in large
quantities to China.

1 Very unfortunate is the destruction of the "king-crab," Limulus,
which is only distantly related to the Decapoda. In Delaware Bay they
are caught in great numbers and ground up as fertilizer. As they are
taken only during the breeding season, they are being rapidly extermi-
nated. The American Limulus belongs to an order entirely unrepresented
011 the European coast (Fig. 110).

THE CRAYFISH AND ITS ALLIED

115

Development of Lobsters. — Lobsters lay eggs in July and
August. In the fall they migrate to deep water, and pass
the winter there. In the spring they migrate back to the
shore — the females tarrying behind the males until the
eggs of last summer, which she still carries attached to
her swimmerets, shall be further advanced. In June the
young hatch out, moult, and swim to the surface. The

FIG. 111. — An early stage of develop-
ment of egg. Appendages becom-
ing bifid. Paired dotted areas
above indicate eyes ; these are fol-
lowed by the first three paired ap-
pendages : aiitennules, antennae,
and mandibles. Below in the mid-
dle line is the forming tail; above
is the mouth. After Herrick.

FIG. 112. - - Surface view of egg
nauphius. Antennae show begin-
ning of segmentation; mandibles
and maxillae seen on each side of
the abdomen. Embryo 10-18 days
old. X 25. From Herrick.

female now moults, 1m t does not spawn again for a whole
year ; that is, she spawns in alternate years. The number
of eggs carried varies with the age of the female ; middle-
aged lobsters may carry up to one hundred thousand eggs,
but the old or young ones as few as three thousand. The
egg as freshly laid is about 1.5 millimetres in diameter and
is stored with food material, called yolk, much as in the
case of the hen's egg. As in the chick, the development

116

ZOOLOGY

takes place, as it were, on top of the egg (Figs. Ill, 112).
Eyes and mouth appendages early make their appearance;
then the other appendages, and the tail (Fig. 113). For
a long time the back of the thorax is greatly distended by
the yolk stored there, and the eyes are huge (Fig. 114).

Immediately after hatching, the young lobster is about
one-third of an inch long. The eyes are still abnormally
large, the telson is spatulate, and the abdomen is without

FIG. 113. — Surface view of embryo FIG. 111. — Lobster embryo. 01 days
with all of thoracic appendages old ; eyes have developed pigment,

formed. The forked telson partly X 15. From Herrick.

overlies the brain. Note the large
eyes, which are yet without pig-
ment. Embryo about 21 days old.
X 25. From Herrick.

swimmerets. On account of its resemblance to the Schizop-
oda, the larva at this stage is known as the " Schizopod
larva' (Fig. 115). In moulting for the fourth time, the
exopods are lost from the future walking appendages, and
the animal resembles a lobster except for its small size (Fig.
115a). During these early moultings the young lobsters
undergo a terrible mortality, so that out of ten thousand
embryos hardly two, on the average, survive. After the

THE CRAYFISH AND ITS ALLIES

117

fifth or sixth moult the little lobsters sink to the bottom,
and then begin their journey shoreward. From this time
until they are about four inches long, only very few indi-
viduals have ever been seen. This is due, it is said, to
the fact that they hide deep down among the rocks, where
they cannot be dredged. When they are four inches long
or so, they become bolder, leave the rocks, and, like the

FIG. 115. — Larval view of lobster, extracted from an
egg which was about ready to hatch. The concretions
in the intestine are destined to go into the newcuticula
after moulting, x 25. From Herrick.

adults, make burrows for themselves in the sand or under
stones.

Development of Crayfish. — The crayfish develops simi-
larly to the lobster, — from a large egg filled with yolk.
The early stages are much like those of the lobster ; but
those changes which in the lobster take place during the
first three stages of free life are in the crayfish passed in
the egg. Consequently at the time the crayfish hatches it

118

ZOOLOGY

is almost, but not exactly, like an adult crayfish except
in size. The telson of the just-hatched crayfish has, to be
precise, a somewhat more oval form, and the first pair of
swimmerets are undeveloped; but these differences soon
disappear.

FiG.lloa. — Third larval stage,
lateral view. Note the dif-
ference between this and
the adult. X 11. From
Herrick.

Regeneration of Lost Parts. - -If you attempt to pick up
a crab by one of its claws, you frequently find yourself in
possession of a portion of the leg only, while the crustacean
has made good its escape. Moreover, it will be seen that
the leg always separates at a certain place ; namel}r, be-
tween the second and third segments. This is the place
where a fusion occurs between two segments which are free

TIIE CRAYFISH AND ITS ALLIES 119

in the first larval stage. This power of defensive mutila-
tion occurs in those appendages which are most apt to be
seized, — namely, the five thoracic legs, — and is wholly
under the control of the reflex nervous system, for it may
occur when the entire voluntary nervous system has been
removed. The leg of a dead crustacean shows no such
capacity. If the leg of a lobster is cut off at some point
distal to that of normal rupture, the limb will later be
found cast off up to this point. Here a sort of double
membrane or diaphragm exists, with a central opening
only large enough to admit the passage of nerves and
blood-vessels. Upon rupture this passage is soon plugged
up by coagulated blood — • clearly a device to prevent ex-
cessive hemorrhages. Soon after a leg is cut off a papilla-
like body grows out from the stump of the limb, develops
into the shape of a small limb, and grows larger, with
each successive moult, until the normal size is reached.
The antennse, too, are much exposed to injury, but with
them autotomy is not practised. The}^ begin to grow out
at the place of injury, and at least one moult is necessary
for their complete restoration.

Abnormalities in the claws of the lobster are not un-
common. The thumb-like protuberances of the next to
the last of the joints of the great claw is sometimes bifid,
or carries a large wart. The finger which opposes the
thumb is also sometimes forked (Fig. 116). Many of
these abnormalities are probably due to injury of the claw;
but others cannot be explained in this way. For instance,
cases have been observed of lobsters having crushing
claws of equal size on the two sides of the body. An
antenna has been seen replacing an eye, and this result
may be obtained by cutting off an eyestalk near its base

120

ZOOLOGY

when an antenna will regenerate (Fig. 117), one or two
extra oviducts may occur, or double monsters — sort of

Siamese twins - - may be hatched
out. Similar monstrosities are
found in other arthropods.

Physiological Division of Labor.
The difference between a
" highly developed " animal and a
lowly organized one is not first
of all a difference of size nor a
difference in the number of parts,
- just as a large population or
numerous cities are not the pri-
mary characteristics of a highly
civilized state. But just as a
complex civilization is one in
which each of the different citizens
has his own special task to per-
form for the commonwealth, so
a highly developed organism is
one in which each different o reran

has its special role to play. The
worm Nereis has more segments

to the body than the crayfish, but
these segments are very nearly
alike — the parapodia especially

FIG. lib. — Two abnormal claws. J

Upper figure shows a double are quite similar. In the crayfish,

CrCe°ther^TextS °" the other hand, the append-
finger. From Herrk-k. ages are dissimilar. Each pair

has a special function to perform

and is specially adapted, often complexly fashioned, to
meet this need. What is true of the appendages is like-

777 K CRAYFISH AND ITS ALLIES

121

wise true, to an equal degree, of the internal organs. The
internal organs of Nereis are repeated in each segment; but
in the crayfish the egg-ducts lie in one segment, the heart
in another part of the body, and so on. Some of the seg-
ments have given up one or more functions to perfect a

Fiu. 117. — Eyestalks of a Decapod dissected out. Oil the right an antenna
has regenerated in place of the amputated eye. opt., optic nerve. After
Herbst.

single one in which it lias specialized. There has been a
division of labor between the different parts of the body,
and in consequence a greater perfection in the performance
of each function. More perfect fulfilment of function is
the result of physiological division of labor, just as a higher
civilization is the result of individual division of labor.

122

ZOOLOGY

APPENDIX TO CHAPTER YII

KEY TO THE SIX CHIEF ORDERS OF MALACOSTRACA

Body segments, 20 ; abdomen with 7 segments ;

at least 1 pair of maxillipeds.
61. Cephalothorax with carapace, at least 2 pairs

of maxillipeds [Thoracostraca].
Ci. Eyes stalked.

d\. No uncovered thoracic segments ; 3
or 2 pairs of maxillipeds, and 5 or
6 pairs of legs ....

<72. 3 free thoracic segments ; 5 pairs of

maxillipeds ; 3 pairs of legs
c2. Eyes not stalked ; 4 to 5 thoracic seg-
ments not covered by carapace ; 2 pairs
of maxillipeds ; 6 pairs of thoracic legs
b'2- Cephalothorax without marked carapace ;
usually 7 free thoracic segments ; only
1 pair of maxillipeds ; eyes not stalked
[Arthrostraca].

d. Body usually broad ; abdomen with short,
often-fused segments, and with gills

on legs

c2. Body laterally compressed ; abdomen
mostly elongated, with 3 pairs of swim-
ming legs, and behind them 3 pairs of
springing legs .....
«o. Body segments, 21, enclosed in bilobed shell,
abdomen with 8 segments ; the last 2 without
appendages ; no maxillipeds [Leptostraca]

Podopthalmata

(Ex. Crayfish)

Stomatopoda

Cnmacea

Isopoda

Amphipoda

Neb ali <v

The crayfish belongs to the order Podopthalmata. The following is a
key to the most important families of this order : —

«i. 3 pairs of maxillipeds which differ in form from
the following 5 pairs of thoracic legs ; the latter
are locomotor, and often end in pincers [sub-
order Decapocla].

APPENDIX TO CHAPTER VII 123

Body mostly depressed ; antennae short ;
abdomen short and folded under the cepha-
lothorax, with 1 to 4 pairs of appendages,
and usually without tail-fin [superfamily
Brachyura].

Ci. Male duct opens on thoracic plate ; ce-
phalothorax usually quadrangular, at
times transversely oval; anterior lateral
area (liver area) of carapace small ;
usually fewer than 9 pairs of gills; orbits
look forward or obliquely downward . Catometopa

(Square Crabs; Fiddler-crabs)
C2. Female opening on broad thoracic plate ;
male opening on coxa of 5th pair of
thoracic legs ; 9 pairs of gills.
d]_. Cephalothorax broad, diminished be-
hind, bowed in front ; liver area
large ; orbits directed obliquely up-
ward and forward .... Cyclometopa

(Arched Crabs)
dz- Cephalothorax triangular, anteriorly

pointed, with longer or shorter ros-

trum ; liver area small ; orbits di-
rected outward .... Oxyrhyncha

(Triangular Crabs ; Spider-crabs)
Body mostly elongated ; antennae long ; ab-
domen long, not bent under, or only partly
so, typically with 5 pairs of legs and a large
tail-fin [superfamily Macrura].
c\. Last pair of thoracic legs shoved back-
ward and rudimentary.
d\. Last thoracic segment not free ; ab-
domen with hard shell, hinder half
turned under ; first pair of legs
typically non-chelate . . . Hippidce

(Mole-crabs)
c?2- Last thoracic segment free ; abdomen

typically with thin cuticula, un-
symmetrical and with rudimentary
legs ; first pair of legs very large,
chelse unsyrnrnetrical , . Paguridce

(Hermit-crabs)

124

ZOOLOGY

C2. Last pair of thoracic legs not shoved

backward.

6?i. Antennae without squame ; first pair
of thoracic legs chelate ; cephalo-
thorax with 2 longitudinal lines .
d%. Anteniue with squame.

e\. ISquame small ; antennules and
antennas near each other ; first
pair of thoracic legs very heavy
with great chelae ; cephalo-
thorax with cross-suture ; gills
brush-like

6>2. Squarne large ; antennas usually
under antennules ; first pair
of thoracic legs with small
chehe ; cephalothorax without
cross-suture, gills laminate

ThalassimdcB

Astacidcb

(Ex. Craylish)

C arid idee

(Shrimps and Prawns)

n-2. 2 pairs of maxillipeds resembling the 6 following
pairs in being bifid [suborder Schizopoda].

CHAPTER VIII

THE DAPHNIA AND ITS ALLIES

Relationships. — Daplmia1 belongs to the division of
Crustacea called Entomostraca.2 The Entomostraca 3 are
distinguished from the higher Crustacea — the Malacos-

O <— '

traca - -by the negative character that the number of
segments and appendages in the body is variable, instead
of there being constantly 10 pairs of appendages.

The group of Entomostraca to which Daphnia belongs
comprises the more primitive of living Crustacea. They
occur in both fresh and salt water and, excepting Protozoa,
are the most abundant aquatic animals. They are of great
economic importance, since they constitute the main food
supply "of fish. On the coast of Norway and Scotland the
fishermen prepare for a catch of herring or mackerel when
the sea becomes red with Entomostraca. Whalers like-
wise seek their booty where these Crustacea are abundant
on the open seas, for even the whalebone whales devour
the small animals in great quantity, straining them out of
the sea-water by means of their whalebone strainers. De-
spite all their enemies, the numbers of Entomostraca are
maintained by virtue of an enormous fertility. The

1 From Aa0i/77, daughter of the river-god Peneus ; she was transformed
into a laurel tree.

- efTo.i'.oi', cut into, segmented ; oarpaKov, shell.

3 The live orders of Kntomostrara may be distinguished by means of
the key given at the end of this Chapter, page 131.

125

126 ZOOLOGY

Entomostraca are rich in species also, partly because they
occur in such diverse environments. Thus they live in
fresh water, in the sea, and even in the Great Salt Lake
and in vats where salt is crystallized out. They live in
little pools, such as dry up in summer. They are found
also as parasites on the gills or in the skin of fishes.

Habitat and Food. - - Daphnia 1 lives in ponds, lakes, and
slow-running streams over all the globe. During the fall
in northern latitudes the Daphnias, of at least certain
species, lay fertilized eggs, called winter eggs, which may
lie dormant, however, not merely for the winter but
throughout an entire year. During most of the year
females alone occur and unfertilized "summer eggs" are
alone produced.

The abundance of Daphnia in any pond is determined
by a number of causes. One of the most important of
these is food. The food of Daphnia consists chiefly of
fresh-water algre, such as nostocs and diatoms ; and it has
been shown that the abundance of Daphnia in a pond is
closely determined by the abundance of the kind of alga

1 Key to the principal genera of the family Daphnidse : —

a i. Head rounded, not beaked.

&i. Antennules long ; abdomen not wholly cov-
ered by shell Moina

b-2. Antennules short ; whole body enclosed in

shell Ceriodaphnia

a-2- Head beaked below.

bi. Beak slight ; shell angled below or extending
in long spines from lower angle ; pigment
spot roundish Scapholeberis

ft2. Shell rounded below, with a blunt spine above ;

pigment spot elongate .... Simocephalus

63. Shell extending in sharp spine at upper pos-
terior angle ; pigment spot small . . Daphnia

THE DAPHNIA AND ITS ALLIES

127

ant.i
ant.Z

abd.f

which forms its principal food. Another factor upon
which the number of Daphnia in a pond depends is tem-
perature. A high temperature seems to be unfavorable to
Daphnia, so that not the
summer, but the spring and
autumn are its periods of
maximum reproductive activ-
ity. This activity is like-
wise checked in winter even
though there is plenty of
food.

The family Branchiopoda 1
is closely allied to the Clado-
cera. The common repre-
sentative of this family,
Branchipus, has an elongated,
distinctly segmented body
whicli carries eleven pairs
of lobed, leaf-like feet, func-
tioning both as respiratory
and locomotor organs. Like

Daphnia, Branchipus pro-

- • FIG. 118.--Apus glacialis, ventral

dlices Winter eggs Which Can aspect, abd.f., abdominal feet;

Withstand desiccation even «nt' f > antennule ; ant. 2, antenna ;

lor., labrum ; ma., mandible ; mx.,
for years ; indeed, in Some

cases, a certain amount of
desiccation is a prerequisite
of hatching. Apus differs
from Branchipus in having a broad shield (Fig. 118).
The family Ostracoda2 comprises some very abundant,

1 j3pdyxia-> gills ; Totfs, foot.

2 HxrrpaKov, shell of a testacean ; eI5os, like.

first maxilla; ov., aperture of ovi-
duct: .s. /. pi., sub-frontal plate;
•s7f. f/l., shell-gland; tli.f., thoracic
feet; th.f. 1, first thoracic foot.
After Bernard.

128

ZOOLOGY

minute, bean -shaped little crustaceans, which have to move
their appendages very vigorously to support their heavy
bodies in the water. The Ostracods are found in almost
all pools and streams,, especially in the early spring. Many
of them seem to be exclusively parthenogenetic.

FIG. 119. — Acartia, a marine Copopod. Greatly magnified. Photo, by

W. H. C. P.

Of the Copepoda1 the commonest fresh-water genus is
Cyclops, which occurs in a similar habitat witli Daphnia
and is sometimes found even in pure drinking water.
The female carries a conspicuous egg-sac on each side of the
abdomen, and reproduction occurs with such rapidity that

oar ; Trews, foot.

THE DAPJfNTA AND TTS ALL1KS

129

one Cyclops might, under the most favorable conditions,
have 5,000,000,000 descendants in one year. It is conse-
quently easy to understand how Cyclops often becomes
the most abundant eiitomostracan in our waters, and how
in some lakes it has been found that there are over one
million of them to each square metre of water surface.
Large numbers of the Copepoda are marine. One of the
most common is Acartia (Fig. 119), which swarms to such

FIG. 120. — Mussel-shell bearing barnacles (Balauus). Photo, by W. H. C. P.

an extent on the surface of the water as to make great
phosphorescent areas.

Barnacles are the only attached non-parasitic Crustacea.
Certain species of them are found fastened to rocks on the
seashore at low-tide mark. If you watch barnacles in rock
pools, you can see them open the valves of their shells,
protrude their elongated appendages, which together form
a sort of rake, and pull in particles which happen to be float-
ing about them. Other species of barnacles attach them-
selves to floating seaweed, ship bottoms, and whales ; under
these circumstances, despite their sessile habit, they enjoy a
constant change of locality. Barnacles doubtless gain
great protection from the circumstance that they are

130

ZOOLOGY

sessile and enclosed in shells ; but their peculiar habits
have given rise to certain peculiarities in reproduction.
They are hermaphroditic; i.e. both male and female germ-
cells occur in the same individual. Despite this fact,
dwarf male individuals are occasionally found inside the
shell of the barnacle ; these are known as " complemental
males." The general form of the barnacles has also be-

come greatly modified by their
sessile habit, so that they
were long regarded as mol-
lusks, until it was shown that
the larvje are almost exactly

like those of other Ento-
mostraca.

Trilobites1 are extinct giant
Entomostraca, closely allied
to Branchipus. They were
immensely abundant in early
geologic times, and their re-
mains form a large part of
certain rocks. They had a
segmented body, with bifid
appendages and long antemue,

T ,1 T

- 101 . , ,. and their compound eyes were

FIG. 121. — A restoration of the J

borne on the great frontal
""eld. Some of them were
Beecher. nearly half a metre long.

ventral aspect of a Triiobite.

1 Having three lobes.

APPENDIX TO CHAPTER VIII 131

APPENDIX TO CHAPTER VIII

KEY TO THE FIVE ORDERS OF ENTOMOSTR A.CA

a\. Free-living or parasitic inhabitants of the sea or

of fresh water.
?>i. 2 pairs of maxillae.

t'i Mandible without palp ; 4 or more pairs
of foliate swimming legs behind maxillae
[Phyllopoda].
di. With 10 to 40 pairs of legs . . Sranchiopoda

(Ex. Branchipus)

(Z2. With 4 to 6 pairs of legs . . . Cladocera

(Ex. Daphnia)

Co. Mandible with leg-like palp ; only 2 pairs

of appendages behind maxillae . . Oatramiltt

60. Only 1 pair of maxillae, followed by 4-5 pairs

of bifid, oar-like feet ; often deformed as a

result of parasitism Copepnda

(Water-fleas)

«o. Sessile marine animals, whose body is surrounded
by a usually calcified mantle ; 6 pairs of tendril-
like feet Cirripedia

(Barnacles)

Key to the principal families of Cladocera, to which group Daphnia
belongs : —

a\. Body enclosed in a bivalve shell ; mandibles trun-
cate below ; maxillae distinct, spiny.

61. 6 pairs of similar, foliaceous, distinctly

branchiate feet ; swimming antennae with
2 unequal ranii ; intestine straight . . SididcK

b-2. 5 (or 6) pairs of feet, the anterior pair more
or less prehensile and destitute of branchiae.
Ci- Ranii of antennae 3- and 4-jointed ; 5
pairs of feet, the last with a curved
appendage guarding the branchial sac ;
antennules of the female sort, 1 -jointed Daph nidus

132

ZOOLOGY

Co. 0 pairs of feet ; an ten miles elongated,

many-jointed . . . .

Cg. Antennae with both ranii o-jointed ; in-

testine convolute .....

Body wholly or nearly destitute of a bivalve shell ;

feet not branchiate, spiny ; abdomen curved,

ending in two long stylets

Bosminidce
Lynceuhe

Polyphemidce

CHAPTER IX

THE EARTHWORM AND ITS ALLIES

Relationships.- -Earthworms1 belong to an order of
Annelids known as Oligocheeta.2 This group is distin-
guished by a prevailingly non-marine life, by the absence
of parapodia, by few bristles, and by the absence of tenta-
cles, palps, cirri, and gills.3

Habits. — Earthworms, as the name implies, are inhabit-
ants of the ground, through which they burrow and in

FIG. 122. — Flash-light photograph of earthworm and slug crawling on a pave-
ment at night. Photo, by D. and S.

1 There are not very many kinds of terrestrial Oligochseta. The prin-
cipal American species may be distinguished with the aid of the key given
in the Appendix to this Chapter.

- 6X1705, few ; XCU'TT?, hair.

3 The Oligochfeta exhibit two principal subdivisions ; the first of which
includes terrestrial species of the single family Lumbricidse, and the
second various aquatic families, — a key to which is given on page 144,

] 33

134 ZOOLOGY

which they gain their food. They sometimes come to the
surface at night in search of companions and food (Fig.
122). Even during the day in rainy weather they extend
the anterior end of the body out of their burrows. Earth-
worms, found on the surface at other times, have, for the
most part, been parasitized by a fly, and are in consequence
weak or dying. During the daytime, if the surface mois-
ture permits, they lie near the mouth of their burrows,
probably for the sake of the sun's warmth. In this posi-
tion they can be seen by looking down into the holes. At
such times they are often caught by birds. In dry weather,
or when the ground is freezing, earthworms burrow deep
to a moist stratum, or to below the frost line, and hiber-
nate there.

Food. — EartliAvorms are omnivorous. As they burrow
through the ground, the earth is taken into the alimentary
tract, and the digestible particles are dissolved out and
absorbed as food. Earthworms can, however, be fed upon
green and dead leaves, decajdng wood, seedlings, bits of
flesh, and even filter paper. Earthworms have the habit
of dragging into their burrows leaves which they intend
to devour. There the leaves are moistened with a fluid
excreted by the worm. This fluid partially digests the
food. After being taken into the alimentary tract, the
food reaches an organ of the canal known as the gizzard.
This part has thick muscular walls, and contains in its
cavity small stones ; by the action of both the muscular
gizzard and the small stones, the food is ground up in
much the same way as are the grains of corn by the aid of
stones in the gizzard of a hen.

Resistance and Regeneration. - -The capacity which earth-
worms possess of resisting certain untoward conditions is

THE EARTHWORM ANT) ITS ALLIES 135

very great. Thus they may be kept for months in a
moist vessel without food, or with only filter paper, with-
out starving. On the other hand, they die in a dry atmos-
phere in a few hours, whereas they may be submerged in
water for several days without injury. Very remarkable is
their power of healing after injury. If an earthworm be
cut in two near the middle, and the halves be kept under
favorable conditions, each half may develop its missing
organs so that two complete worms will result. The
anterior half of one worm may be attached to the hinder
end of a second worm by the cut edges, owing to the
fact that the cut edges grow together. This operation
is called grafting.

Economics. - - Earthworms are, to a certain extent, in-
jurious to vegetation, since they eat tender seedlings and
roots, but, on the other hand, they are almost indispensable
to agriculture. Their burrows permit rain to percolate
deep into the ground, instead of running off on the sur-
face. They keep the soil loose, facilitating the penetration
of the roots of plants. The earth that passes through
their bodies is ejected on the surface of the ground near
the openings of their burrows, and is called a " casting."
By means of castings the deeper-lying earth is brought to
the surface, and the surface layer of rich earth, called
" vegetable mould,'1 is in this way increased in thickness
by additions to its upper surface. The thickness of the
layer of mould which the castings of one year, if uniformly
spread out, would make has been estimated by Darwin to
be in England about two-tenths of an inch. Most of these
castings are merely taken from the deeper-lying mould,
but they are enriched by the intestinal secretions in pass-
ing through the body of the worm. These intestinal secre-

136 ZOOLOGY

tions are said to have the power of slowly dissolving sand
and thus of turning it into soiL Darwin says, " It is a
marvellous reflection that the whole of the superficial mould
over any smooth expanse has passed, and will again pass,
every few years, through the bodies of worms. The plough
is one of the most ancient and most valuable of man's
inventions, but long before he existed the land was, in
fact, regularly ploughed, and still continues to be thus
ploughed, by earthworms."

The group to which earthworms belong is closely related
to that which includes Nereis of the seashore. They are
both ringed worms or Annelids.1 But whereas Nereis and

its allies have parapodia provided with numerous bristles,
the earthworm has 110 parapodia, and only a few bristles
on each segment. The group to which Nereis and its
allies belong is called (see Chapter X) Polychseta, and
the group to which the earthworm belongs is appropriately
named Oligocliceta.

The aquatic Oligochaeta2 are among the commonest
inhabitants of ponds and ditches, living sometimes in the
mud and sometimes at the surface of the water.

Tubifex3 is common in slow-running brooks, and lives
in the mud of the bottom, forming tubes in it. The
thread-like bodies of the worm are stretched up beyond
the surface of the mud and wave in the water in graceful
undulations. Often the worms are so numerous that their
reddish color gives a decided tinge to the bottom. They
thrive well in fresh- water aquaria.

1 Annulus, a little ring.

2 A key for the determination of the principal families of aquatic Oligo-
chseta is given in the Appendix to this Chapter, page 144.

3 tubus, tube ; face re, to make.

THE EARTHWORM AND ITS ALLIED

137

Dero 1 is very common on the surface of ponds, particu-
larly in the midst of duck-weed (Lemna), the leaves of
which it cements together to form a floating tube in which
it lives, and by which it is accompanied in all its migra-

Fm. 12o. — Dero, the duck-weed worm. Enlarged. After Reighard. The
lettering is as follows : or., mouth ; phx., pharynx ; oe., oesophagus; ftff. <>.,
segmental organ ; in., intestine; pav., pavilion or tunnel; dg. app., finger-
like appendages. From Reighard.

tions. Dero can also be told by the sort of funnel at the
hinder end of the transparent body, from the margins of
which finger-like filaments arise which aid in respiration
(Fig. 123).

Nais2 does not construct tubes, and it has no respiratory

, to skin (= flay).

2 PCUS, a water-nymph.

138

ZOOLOGY

filament at the hinder end of the body (Fig. 124). It also

has eyes ; while Dero has none. Both Dero and Nais have

the interesting habit
of reproducing by
dividing the body
transversely. In the
middle of the body
tentacles begin to
arise, a new mouth is
formed, and the worm
constricts into two.
I n d e e d, sometimes
several new heads may
be forming in the
midst of a single
worm. This habit is
of advantage not only
in multiplying the
number of individuals
of the species, but also

as a means of protection. For if, by chance, the larva of

the water-beetle Dytiscus seizes a Nais

and bites it in two, the part which escapes

can go on developing new^ individuals.
The slow-moving, burrowing habit of

the earthworm has led to a nearly complete

absence of such appendages as Nereis

possesses. There are other ringed worms

i • T , i i . i -i •, FIG. 125. — Phasci)-

in which the burrowing habits have led to iosoma, a Gephy-

a loss even of the segments in the adult. rean- One-fourth

r™ • • , i ,-, ,. nat. size. From

11 us is the case in the group Gephyrea.1 Leunis.

1 ytfivpa, bridge ; because they were once considered to bridge the gap
between holothurians and worms.

FIG. 124. — Nais: a, mouth; b, anus; c, intes-
tine. From Leunis.

THE EARTHWORM AND ITS ALLIES

139

This group contains several rather rare animals. One

of the commonest is Phascolosoma,1 which is a tough but

smooth-skinned, cigar-shaped worm, which one can dig up

on our sandy beaches (Fig. 125). One end is pointed ;

from the other a great proboscis

terminating in tentacles surround-

ing a mouth can be extruded.

Another species found on our

beaches after a storm, something

like a small cucumber in shape and

size, has a row of bristles at each

end, indicating its relationship

with the bristle-bearing worms.

This species, Echiurus,2 is seg-

mented when young like Nereis,

but eventually it loses its seg-

mentation (Fig. 12(>). Several

species of Sipimculus are edible,

and are held in esteem by the

Chinese.

To the account of the Oli-
gochreta above given may be

postset

added some statements concern- Fm'

one-half nat. size.

About
prob.,

proboscis ; ant. set., anterior
seta;; post, set., posterior
setjB. After Greef, from Par-
ker and Haswell's " Text-
book."

ing a group of annelids of very
different appearance. The leeches,
or " blood-suckers," are flattened
Avorms, Avhich, like the earthworm,
show metamerism ; that is, there is a repetition of the in-
ternal organs. They are also segmented ; that is, the
body has external rings, although they may be obscure.
One segment' does not, hoAvever, as in the earthworm,

1 0d(TKa;\oj, sac ; <rw/xa, body. 2 e'x<s> adder ; ot)/>d, tail.

140

ZOOLOGY

correspond with one metamere, but there are three, four,
or five segments to a metamere. Leeches have no para-
podia and no bristles ; but they have a sucking disk at
the posterior end of the body for the purpose of adhesion
(Fig. 127). They usually have a smaller, anterior sucking
disk around the mouth, which may or may not be provided
Avith teeth, for the purpose of cutting through the skin.
When there are no teeth, the pharynx is protrusible,
forming a proboscis. With a few exceptions, all leeches

FIG. 127. — Clepsine, the flat blood-sucker. Ventral view. Posterior sucker at
left. Nat. size. From life. Photo, by E. R. D.

live in water ; but in Ceylon there is a land leech which
lives in foliage and attacks man and other animals. ( Hlier
leeches may live in damp places at a considerable distance
from water. Leeches suck the blood of fishes and other
aquatic animals. Certain kinds devour worms, insects, and
other small creatures.

The commonest of the larger blood-suckers of our waters
is Nephelis,1 which is not distinctly segmented. It" varies
from black to slate color, and is sometimes striped or
spotted. It lives in running water, in ditches, and ponds.

7, wife of Atliamas.

THE EARTHWORM AND 7TN ALLIES

141

Clepsine1 is a very flat and broad leech, which is
common under floating wood. It feeds on snails and
creeps like the inch -worm. The female carries its young
attached to its under surface (Fig. 127).

FIG. 128. — Pedicellina americana, an encloproctous bryozoan. A colony,
magnified 15 diams. Photo- of living animals by W. H. C. P.

Possibly allied to the Gephyrea is the group of Bryozoa,2
or moss-animals. These are noteworthy from the fact that
they are compound, many individuals budding off from one
another, as in plants. They are found abundantly both in
the sea and in fresh water. Two main groups are dis-

1 From K-XeVTw, to steal. 2 fipvov. moss ; faov, animal.

FIG. 129. — Buyula turrita, a marine ectoproct. A colony, magnified 1.5
diams. Photo, of living animals by W. H. C. P.

FIG. l.'it'. — PlumateUa polymorpha, a fresh-water ectoproct, magnified 1.5
diams. Photo, of living animal by W. H. C. P.

142

APPENDIX TO CHAPTER IX

14°

tiiiguislied, the Endoprocta (Fig.
128), in which the individual consists
of a long stalk and a " head ' or
body proper ; and the Ectoprocta
(Figs. 129-131), usually without
such a stalk. The Ectoprocta are
the prevailing type. The marine
species form lace-like mats on sea-
weed or stand up as branching, bushy
colonies (Fig. 129). Some of the
fresh-water forms make loose, antler-
like colonies (Fig. 130), while others
lie on the surface of a more or less
spherical mass of jelly which they
have themselves secreted (Fig. 131).

FIG. -131. -- Pectinatella maf/nijica,a, dense complex of colonies, growing upon
a stick. Each star-shaped group represents a single colony. One-half uat.
size. Photo, of living mass by W. H. C. P.

APPENDIX TO CHAPTER IX

KEY TO THE PRINCIPAL SPECIES OF EARTHWORMS OF THE

UNITED STATES

ffi. Clitellum begins on segment xiii or xiv ; $ pore
on segment xviii or xix ; 2 gizzards in segments
v and vi.

61. 2 dorsal vessels ; lives in soil of prairies

62- 1 dorsal vessel ; lives in river-bottom land
Clitellum does not begin in front of segment xviii ;
$ pore on segments xii and xiii, or (usually) xv.
61. Prostomium incompletely divides buccal lobe
[genus Allolobophora],

( Diplocardia
\ commit nis
D. riparia

144 ZOOLOGY

ci. Tubercles on segments xxviii-xxxi ; ill-
smelling ; purple-banded ... A. fcetida

Co. Tubercles on segments, xxxi and xxxiii . A. caliyosa

r3. Tubercles 011 segments xxvii, xxviii ;

color reddish brown .... A. tumid a

r4. Tubercles on segments xxiv-xxx ; about

100 segments ..... A. parva

05. Tubercles on segments xxviii-xxx . A. subrubicunda

c$. Tubercles on segments xxix-xxxi (occa-
sionally xxix, xxx); number of seg-
ments, 150 A. rose a

62- Prostomium completely divides buccal lobe
[genus Lumbricus] .

Ci. Tubercles on segments xxviii-xxxi ; red-
brown or purple ; about 120 segments. L. ntbellus

Co. Tubercles on segments xxxiii-xxxvi ;

number of segments, 180 L. hercnleus

KEY TO THE PRINCIPAL FAMILIES OF AQUATIC OLIGOCH^ETA

a\. Dorsal blood-vessels visible only in the anterior
part of the body ; farther back, as intestinal
sinus, disappearing underneath the intestinal

glands EnchytneMas

rto. Dorsal blood-vessels running on top of food canal

and visible throughout its entire length.
&i. In each segment, except the first, contractile

lateral blood-vessels Lumbriculidas

bo. Lateral vessels contractile only in anterior

segments.

Ci. Dorsal and ventral vessels united in each
segment, except in the first 5, by 2
lateral vessels Tubificidce

(Ex. Tubifex)

Co. Dorsal and ventral vessels united in each

segment by a lateral vessel . . . Naidce

(Exs. Nais, Dero)

CHAPTER X

,-*

NEREIS AND ITS ALLIES

NEREIS1 is one of the commonest worms found on our
seacoast. It occurs in sandy or muddy beaches, at or
below low-water mark, especially where tidal currents flow
swiftly. It inhabits burrows, which it makes in the sand
and lines with a mucilaginous secretion to bind together
the walls of sand or mud. At certain seasons of the year,
during the breeding season, these worms may be found
swimming near the surface of the sea.

Nereis lives on both plant and animal food. To capture
its prey it thrusts out a long proboscis, provided with two
powerful jaws. The thrusting out consists essentially of a
rolling inside out, — just as the finger of a glove may be
rolled inside out. When the proboscis is rolled in again,
the jaws, retaining their grip on the food, carry it into the
food canal. While many kinds of small animals serve
Nereis as food, it is itself devoured by various fishes which
dig it out of the sand or capture it when it swims free at
night or during the breeding season. Such a favorite with
fishes naturally makes excellent bait, and is well known to
fishermen under the name " clam-worm " or "sand-worm."

Nereis is distinguished by the fact that its segments are
numerous and nearly all alike, and bear appendages of
similar form. The single pair of jaws on the proboscis is

ts, daughter of Nereus, one of the Nereids, or sea-nymphs.
L 145

146 ZOOLOGY

characteristic ; and the four eyes on top of the head, com-
bined with two antennae and two palps, serve to determine
its family with precision. The parapodia have a dorsal and
a ventral cirrus. The commonest species on the coast of
New England and in Long Island Sound is Nereis virens,1
which grows to a length of thirty centimetres. Its color is
dull green to bluish green, and iridescent. The gills on the
parapodia are green at the head end, but farther back they
become bright red, owing to the blood which flows through
them. This species lives in northern seas, and is found on
the coasts of Great Britain, Norway, Labrador, and south

FIG. 132. — Euglycera. One-half natural size. Photo, by W. H. C. P.

to Long Island Sound. South of Long Island Sound the
commonest species is Nereis limbata? which grows to a
length of, at most, only fifteen centimetres, and is of a dull
brown or bronze color. This species is found as far south
as South Carolina.

Often associated with Nereis in sandy beaches is a large,
strong, flesh-colored worm, pointed at both ends, so that the
head is not nearly as evident as in Nereis, and having small
appendages, so that it looks smooth like an earthworm. This

1 Green. 2 Bordered or edged.

NEllEIfi AND TT8 ALLIES

147

is Euglycera.1 Its proboscis has four jaws, situated at the
corners of a square, instead of two as in Nereis. The pointed
head and powerful writhing muscles enable the animal to
burrow with great rapidity (Fig. 132).

A second kind, Autolytus,2 is a small animal which
lives in little tubes attached to algre or hydroids (Fig.
133). The parapodia at the anterior
half of the animal are different from
those at the posterior half, for the
latter are large and fitted for swim-
ming. Eventually one of the middle
segments of the body becomes trans-
formed into a head, with eyes and
tentacles, then the whole of the hinder
half breaks off spontaneously. The
newly formed head is now the head
end of the new individual. This
individual leads a different kind of
life from the half which remains in
the tube, for it swims freely in the
water. The separated individuals are
either male or female, whereas the part
which lives in the tube never pro- FIG 133. -1 Autolytus
duces eggs, but merely forms a new
tail every time the old tail is cut off
to form a sexual individual.

A third kind, Lepidonotus 3 is
characterized by the possession of

representative of a fam-
ily of Polychreta in
which the animal bin Is
off male or female in-
dividuals from its hinder
end. bud, head of the
budded individual. After
A. Aijassiz.

1 e5, typical ; rAikepa, a woman's name, also applied to a family of
Polychseta. Euglycera means typical of the family GlyceridaB.

2 auros, self ; AIAJ, to separate ; hence, self-separating.

s, scale ; ^WTOJ, back.

148

ZOOLOGY

a double row of scales covering over the back (Fig. 134).
These scales are outgrowths of the dorsal part of the
parapodia, and serve for respiration. In allied
genera the scales are covered with bristles,
which may be so very long and abundant as
to hide the scales. They produce a brilliant
iridescence. One of these worms with the
great bristles may be several inches long and
relatively broad, and is commonly known as
the "sea-mouse" (Fig. 135). Both Lepido-
notus and the sea-mouse occur in out-of-the-
way places, - - crevices of rocks at low tide

or fairly deep
water, - - so that
they are not com-
monly seen at the
seashore.

The sedentary Polychaeta are
mostly smaller and less familiar
animals than the free-living
Polychseta, but they have an
interest for us in showing how
greatly modified an organism
becomes when it takes on a
sedentary life. Its swimming
appendages become rudimen-
tary ; its eyes are usually lack-
ing ; there is no protrusible
proboscis armed with powerful
jaws ; the gills become grouped
almost exclusively about the

FIG. iai.— Lep-
idonotus, the
scaled worm.
Nat. size.
Photo, by W.
H. C. P."

FIG. 135. — Aphrodite, a sea-mouse.

r. i.).». — r\imn>uiit5, A, Neil-mouse. i c ±1 i ^ i

Nat. size. From Johnston. uPPer end of the bod7> wnere

X Eli Kit* AND ITS ALLIES

140

they can be thrust out of the tube ; the mouth comes to lie at
the bottom of a funnel, which receives as food small parti-
cles floating in the water ; even the segmentation of the
body becomes lost at the hinder end of the animal ; in a
word, all those organs which are useful for active carnivo-

rous life have become re-
duced to the bare needs of
a quiet herbivorous life.

FIG. 1 ;>(.). — Amphitrite, removed from its Fi<;. 137. — Polycirrus, the blood
tube. Nat. size. Photo, by W. H. C. P. spot. Nat. size. Photo, by

W. H. C. P.

The first of these sedentary worms that we have to con-
sider is not completely modified from the type found in
free-living species.

Cirratulus 1 lives in tubes in mud or sand. It is yellow

1 From cirrus, curl, ringlet.

150

ZOOLOGY

or orange in color, and has long cirri, which, arising from
nearly every segment, reach out in all directions. These
function as gills, and when broken off may remain alive
for days.

Clymenella,1 which looks like a reddish, jointed straw,
builds tubes of agglutinated sand, and has a serrated, funnel-
shaped tail end. Its parapodia are very small (Fig. 139).

FIG. 138. — Tube of Cistenides. Nat. size.
Photo, by W. H. C. P.

Fid. 139. — Clymenella, straw-
worm. The anterior seg-
ments only are shown.
After M. Lewis.

Amphitrite2 (Fig. 136) builds firm tubes of sand. From
the head spring numerous tentacles and three pairs of blood-
red gill-tufts. The body is large anteriorly but becomes
slender behind, where there are no bristles. Allied to
Amphitrite are a large number of common worms found
on our coast. Polycirrus, or the blood-spot (Fig. 137), is
somewhat smaller than Amphitrite and characterized by a

1 Diminutive of K\vfj.evr}, daughter of Oceanus.

2 ' A.fjuj>tTplTij, wife of Neptune, goddess of the sea.

NEREIS AND ITS ALLIES

151

uniform crimson color and a large number of cirri massed
at the head. The tubes made by some of the Terebellidee
are very beautiful. The tube of Cistenides (Fig. 138) is
found in the sand under stones and is composed of grains
of sand cemented together and regularly arranged so as to
form a firm wall.

Finally, Serpula1 secretes crooked, round calcareous
tubes, which may be found adhering to stones near low
water (Fig. 140).
From the mouth of
the tube the head,
with its tentacles,
may be protruded,
but it quickly re-
tracts from danger
and closes the open-
ing of the tube as a
marine snail does its
shell, by means of an
operculum or lid.

Some worms have
gained a parasitic
habit, and in con-
sequence have become much modified in form and struc-
ture. Such is the case with some of the round-
worms. Some of these are thread-like, live in springs
or pools, and are regarded by the uninitiated as animated
horse-hairs. Others are spindle-shaped, as for example
the "vinegar eel" and the round- worms that are common
in stagnant water. Others live in the food canal, as for
example the stomach worm (Ascaris) of the horse and the

1 Diminutive of serpens, serpent.

FIG. 140. — Serpula tube on a bit of oyster
shell that is perforated by the boring sponge.
The tube lies in the centre of the figure.
Nat. size. Photo, by W. H. C. P.

152

ZOOLOGY

FIG. 141. — Trichina. A, encysted form in muscle of pork; B, female;
(', male; bh, envelope of cyst; cy, cyst; de, male duct; e, embryos; /, fat
globules; h, testis ; mf, muscle fibre; oe, pharynx; ov, ovary; no, opening
to egg duct; zh, cell masses in intestines. After Clans.

NEREIS AND ITS ALLIES

153

pin-worm of man. Others still penetrate into the mus-
cles, and cause great pain and often death. Such is the
pork-worm, Trichina,1 which gets into man through un-
cooked pork, multiplies in the
food canal, migrates in great
numbers into the muscles and
encysts itself there (Fig. 141).
Another group which is
largely parasitic is that of the
flatworms. Some flatworms
live free in ponds. They will
be found abundantly among
plants taken from small ponds
in the summer and autumn, and
are commonly known as Pla-
naria2 (Fig. 142). They may
be recognized not only by their
flattened form, but also by a
curious proboscis which pro-
trudes from the middle of the
under side of the body and bears

«/

mouth at its tip. These

FIG. 142. — Species of fresh-water
Plaiiaria. 1, Dendrocoelum
lacteum, cream color; -, Pla-
naria maculata ; 3, head end of
same to show light streak.
After Woodworth.

creatures have a marvellous

power of regeneration, so that

every piece into which a worm

is cut will reproduce an entire

one (Fig. 143). If the worm

is mutilated but not wholly cut in two, bizarre forms may

result by a modified tendency to regenerate (Fig. 144).

Other flatworms are parasitic, such as the liver-fluke
of the sheep (Fig. 145). This destructive parasite has a

hair. 2 planus, flat.

154

ZOOLOGY

complicated series of stages to go through before it be-
comes adult. Thus the flukes in the liver of the sheep
produce eggs which develop into embryos. These em-
bryos get out of the liver into the food canal, and thence

-ij:

ec.10.

\J ~Mixrch13.Apr.4-.
Jan.25. FA.5. Fe~b,17

§
|

J)&c.10. V

Jan. 2 5.'

FIG. 143. — Showing results of cutting Planarians into two pieces ; the pieces
develop into entire animals. After Morgan.

to the exterior. If they are deposited near a pool of
water, they may develop further, otherwise they must
die. In the water a ciliated larva l hatches from each
egg, swims about for a time until it finds a fresh-water
snail, bores into it, and encysts itself there. In this

1 Fig. 146, A.

NEREIS AND ITS ALLIES

155

FIG. 144. — Showing abnormal forms
resulting from mutilation of Plu-
narians. After Van Duyue.

encysted stage the worm is
known as a "sporocyst,"
because it is full of germs
(spores) of a new genera-
tion.1 The spores develop
in the snail into curious
organisms, a sort of second-

ary larvae known as redia.2
The redise may produce, by
a kind of internal budding,
new redise, and so on re-
peatedly, until at last, on
the death of the snail, or
from some other cause, the
last generation of redia}
produces liver- flukes.3 The
young liver-flukes wriggle out of the snail, attach them-
selves to damp grass, lose their tails, and encyst them-
selves. If these cysts be eaten by a
sheep, they develop in the sheep's
body into an adult liver-fluke (Fig.
145). Thus the stages which we can
recognize in the liver-fluke are : -

First generation : egg from liver-fluke, larva,

and adult sporocyst.
Second generation : redia (this may be several

times repeated).
Third generation : " cercaria " larva, encysted

larva, and adult liver-fluke.

1 Fig. 140, B. 2 Fig. 140, C.

3 These, while young, have tails, and are called
" cercaria."

ever

FIG. 145. - Distomum,
the liver-fluke. Nat.
size. Excr., excretory
pore; mo., mouth; rep?'.,
reproductive aperture ;
-srA1/*., posterior sucker.
From Parker and Has-
well.

156

ZOOLOGY

Another flat worm is such an abject parasite that it has
lost most of the organs usually possessed by worms. This is
the tapeworm (Fig. 147). When the eggs of the tape-
worm are taken into the body of an herbivorous animal, the
embryos develop there for a way and then stop. When
flesh containing these embryos is eaten by a carnivorous

eye .

(fast.

or.su

c&s

FIG. 146. — Development of Distomum. A, ciliated larva ; /?. sporocyst con-
taining developing rediae ; C, redia, containing a daughter redia and embryo
liver-flukes; D, free-swimming, tailed larva of liver-fluke;- b. op, birth
opening; etit, food canal of redia; eye, eyespots ; gast, young redia; r/erni,
mor, early stages in formation of the embryo liver-fluke; int, intestine of
larval liver-fluke; o?s, oesophagus; or. SK, oral sucker; pap, head papilla of
ciliated larva, A: ph, pharynx; proc, processes of redia; vent, su, ventral
sucker. After Thomas.

animal, the embryos attach themselves to the food canal of

•>

their host and form, by rapid growth, a long chain of seg-
ments, each of which is full of germs. The chain, or

NEREIS AND ITS ALLIES

157

FIG. 147.— Tsenia solium, the human tapeworm. Entire specimen, about
natural size. Cap, head. After Leuckart.

158

ZOOLOGY

" tape," absorbs fluid food, which soaks through its body
wall. As the segments at the older end of the animal
mature, they are set free and pass out of the alimentary
tract, to be picked up, perchance, in the food of an herb-
ivorous animal or else to perish.

The economic importance of parasitic worms is very
great. Thus, although no great epidemics of the flukes

have occurred in this coun-
try, a million sheep are
annually lost by this para-
site in Great Britain ; and
in 1879 and 1880 it was
estimated that three million
sheep died annually in
England alone of this
parasite. In Buenos Ayres,
during 1882, a million
sheep died of fluke disease.
By great care in prevent-
ing infection, especially
during damp seasons, we
may be able to prevent

Fi<i. 148.— Cerebratulus, a cream-colored any such disaster ill this
nemertean. Head end at upper part of

figure ; mouth turned toward observer, ^Y'

proboscis retracted. Instantaneous The 2'1'OUp of Nemertini

photograph of living worm by W.H.C.P. . n- i >T A

is allied to the flat worms.

It includes chiefly marine animals, of somewhat flattened
form and great length, even as great as thirty metres.
They protrude a long, slender proboscis. These worms
are especially abundant in the sand of the seashore,
although land nemerteans occur. Cerebratulus (Fig. 148)
is a common form from the east coast.

APPENDIX TO CHAPTER

159

APPENDIX TO CHAPTEPv X

KEY TO THE MORE IMPORTANT FAMILIES OF POLYCH.^TA

a\. Head distinct from trunk ; proboscis protrusible

[wandering Polychseta].
bi. With broad dorsal scales ....

b-2. No scales ; only one mouth-segment.

Ci. Cirri not leaf-like ; body long and not

flattened.
d\. Head not segmented.

e\. Jaws composed of many pieces .
e-2- Two powerful jaws .

d». Head with its lobes segmented .

c2. Small worms, body flattened, cirri evident

«o. Head not distinctly separated from trunk ; pro-
boscis short, not protrusible ; no jaws [seden-
tary Polychseta].
bi. Gills, when present, arise either from almost

all, or else the middle segments.
GI. Body not separated into various regions ;
distinct head ; no antenna ; gills in
form of elongated, thread-like cirri

C2. Body divided into 2 or 3 different regions ;
no antennal cirri ; proboscis present ;
no gills

&2- Gills almost always present and limited to the

anterior end of the body ; no cirri ; body

divided into an anterior and a posterior part.

Ci. Gills confined to the anterior segments ;

head lobe small ; numerous antenna in

2 bunches ; no antennal cirri

c2. Gills confined to head ; 2 inrolled leaves
standing at the sides of the mouth

Aphroditidce

(Ex. Lepidonotus)

Eunicidce

Nereidu'

(Ex. Nerds)

Glycerida*

(Ex. Ki

(Ex. Antolytus)

Cirratulidce

(Ex. C'irratulus)

Maldanidaz

(Ex. ClymeiH'llu)

Terebellidce
(Ex. Amphitrite)

SerpulidoK

(Ex. Serpula)

CHAPTER XI

THE SLUG AND ITS ALLIES

THE slug belongs to the group of Mollusca.1 This
group contains animals which possess two distinctive
organs — the foot^ by means of which locomotion is
effected, and the mantle, a fold of skin covering over
or enclosing a greater or less part of the body. The
mantle usually secretes on its outer surface a calcareous
shell. Exceptionally, both shell and mantle may be
entirely absent in the adult.

Among the Mollusca, the slug occupies the class Gastrop-
oda,2 characterized by the possession of a head, which bears
feelers and eyes, and an unpaired foot, situated on the
ventral surface of the body and used to crawl upon.3
Gastropods are either with or without an external shell.
When the shell is present, it is made of one piece, that is,
it is univalve^

1 mollis, soft.

- -yao-Trjp, belly, stomach ; TTOUS, foot.

3 A key to the principal families of gastropod shells of the Atlantic
coast of the United States is given in the Appendix, p. 174.

4 The three orders of Gastropoda may be distinguished by aid of the
following key : —

«!. Breathing by means of lungs ; no operculnm ;

living on land and in fresh water . . . Puhnonnta

a2. Breathing by gills ; chiefly marine.

160

THE SLUG AND ITS ALLIES 161

Slugs belong to the group of air-breathing, land-inhabit-
ing gastropods, or Pulmonata.1 They may be found in
the spring, summer, and autumn, under wet, decaying
pieces of wood, under stones or fruit, in the grass, on the
shady side of fences ; in a word, in moist, dark situations.
They especially shun sand, ashes, and sawdust, because
these substances tend to dry up the mucus which they
secrete over their body to retain its internal fluids. Slugs
are nocturnal (Fig. 122), hence they have the reputa-
tion of being rather rare. During the winter they live
in the ground encased in their own slime, but some species
frequent greenhouses in cold weather, and in consequence
of this habit mav remain active all the year round.

*j «/

The food of slugs consists chiefly of the green leaves of
succulent plants, and also of ripe fruit, such as apples.
Our largest slug, Lim«.r2 maximus? is easily maintained

?>i. Gills in front of heart ; mantle-complex on
anterior side of intestinal sac ; operculum
constantly present Prosobranchiata

b-2- Gills behind heart ; if shelled, without oper-

cnlum Opisthobranchiata

Key to the principal families of the American Pulmonata :-

t(i. Eyes at apex of (usually retractile) tentacles.

l>i. With external shell ; 4 tentacles . . . Helicidce

(Ex. Helix)

&2. Without external shell Lhnacidce

(Ex. Limax)

«2- Eyes on inner side or at base of the (non-
retractile) tentacles.
bi. Thick shell, with thick, often-toothed outer

edge ........ Auriculidce

(Ex. Melumpus)

6.2. Thin shell, with sharp margin . . . Limmndce

(Ex. Pbysa)

1 Provided with lungs ; from pulmo, lung.

2 Aet/xa£, naked snail. 3 Largest.

162

ZOOLOGY

in captivity by keeping in a dark box and feeding on the
blanched leaves of cabbage. In captivity one individual
will sometimes devour another.

Of our three principal species of slugs there may be first
mentioned Limax maximus, which gains a length of about
10 centimetres and has a light brown color, marked with
longitudinal rows of black spots along the back and sides.

This species was almost un-
known in this country until
the middle of the sixties, but
it is now widespread through-
out the East. It has doubt-
less been introduced from the
continent of Europe, where
it is very abundant. Second,
Limax ay rest is1 is usually
about 2.5 centimetres long ;
it varies in color from whitish
through gray to black. It is
now common in the eastern
United States, but is believed
to have been introduced from
Europe. Third, Limax cam-

genera figured are: A, Actaeon ; pestris? a native species, is
B, Aplustrum; C, Cylicbna; D, , ,

Atys; E, Phiiine ; F, Doiabeiia; smaller than agrestis, and

its tuberosities are not so
much flattened or plate-like.
It occurs widely distributed
east of the Rocky Mountains.

Economically, slugs are of importance because at times
in some localities they cause much destruction in gardens

1 Living in the field. 2 Living in open fields.

FIG. 149. — Illustrating the transi-
tion of form in the shell of certain
Opisthobranchs, from the pointed
spiral to the almost tiat plate. The

G, Aplysia ; //, Pleurobranchus.
Drawn to various scales. From
Cooke, " Mollusca."

THE SLUG AND I'M ALLIED

168

.c.d

ep-

and greenhouses. Particularly in Europe, Limax agrestis
has often devastated fields of young shoots ; this species
is especially fond of bulbous plants.

In the apparent absence of a shell the slug seems to be
an aberrant gastropod. Other land gastropods — the
snails — have an evident
shell. In Limax the shell
is reduced to a thin, horny ^ J
plate, embedded in the
mantle. Between the con-
dition seen in the snail
and that in Limax there
are intermediate condi-
tions, in which the large
shell is partly covered by
the mantle, and others
in which the shell has
become reduced in size.
In allies of Limax -

a genus called Ario'ti —

FIG. 149a. — Illustrating the gradual
covering of the shell (*7t) in certain
Opisthobranchs by the epipodia (ep] and
mantle ; c. d, cephalic disc. Drawn to
various scales. A, Haminea; /:>, Sca-
phander; C, Aplustrum ; I), Aphysia ;
E, Philine. From Cooke, "Mollusca."

the shell is reduced to a
few calcareous grains.
An exactly similar series
in the degeneration of the shell is found in certain Opistho-
branchs, illustrated in Fig. 149. The beginnings of this
process of covering the shell are seen in many gastropods
in which the mantle edges may protrude beyond the
lips of the aperture, and are folded back over the outer
surface of the shell. A more developed condition is seen
in species like Aplysia, in which the mantle is permanently
reflected.1 In Limax the reflected edges of the mantle

Fig. 149rt.

164 ZOOLOGY

have permanently grown together. The reflection of tl it-
man tie seems to be of advantage by affording additional

protection to the visceral mass.
But after the complete over-
growth of the mantle the shell
seems to be useless, and con-
sequently degenerates.

The Pulmonata are either
terrestrial, like the slug, or
aquatic. Of the terrestrial

Fis. ir,o.- shell of Helix, alboia- pulmoiiates other than the

6m, a common forest snail. Nat. slua- the most important are
size. Photo, by W. H. C. P.

the snails 01 the genus Helix.1

Helix 2 is noteworthy, because it is richer in species than
any other molluscan genus, since it contains over three
thousand species. The distribution of the genus is world-
wide. In North America the snails are most abundant in
limestone regions, consequently they are more numerous
in individuals in the South and West than in granitic
New England. One of the most interesting species is
Helix nemoralis, a European form, which has been intro-
duced into our country at Burlington, New Jersey, and
Lexington, Virginia. At these places it has multiplied
so rapidly, and varied to such a degree, that three hundred
and eighty-five varieties have been enumerated from an
area, at Lexington, not over one thousand feet in extent
in its greatest diameter3 (Fig. 151). Any species of
Helix collected in large numbers is apt to show abnor-
malities in the number of tentacles and of eyes upon the

1 e'\i£, a turning round, as in spire of snail shell. 2 Fig. 150.

3 See paper by Professor J. L. Howe, in American Naturalist, Decem-
ber, 1898,

THE

A NT) TTS ALLIES

165

tentacles. Besides Helix, a very abundant cosmopolitan
land pulmonate is Pupa.1 Being of small size, it is, how-

Fi<i. 151. — Helix n?)n-jralix, from Lexington, Va., collected by Professor J. L.
Howe, showing variation in stripes. Upper line, first figure, normal form,
5 stripes; other figures of first and second lines show reduction of stripes;
third line shows broader (and fewer) stripes (the last figure is very dark
and is poorly reproduced). The shells in the lowest line show more than
five stripes. From a photograph; reduced one-half.

ever, less commonly known. It is found in woods under
leaves or in old stumps and decaying logs, where it feeds.
The shell is many times whorled, and has a
blunt apex.

Intermediate between the terrestrial and
aquatic pulmonates is the family Auriculidye,
the members of which live on the seashore,

in salt marshes or 011 rocks where they FlG- 152- • Me~
, i-i lampus,the salt-

may even be immersed in brackish water marsh snail.

A little girl or doll.

Nat. size. Photo,
by W.H.C.P.

166

ZOOLOGY

at high tides. One of the commonest forms is Melampus
(Fig. 152), found among the roots of marsh grass.

Of the aquatic pulmonates three genera are common and
easily distinguishable. Limnaea,1 the " pond snail," is com-
mon in ditches and muddy or stagnant ponds. Its shell
runs up into a sharp spire, and is right-handed, i.e. hold-
ing the shell so that its aperture
is next the observer and below,
the aperture is at the right
(Fig. 153). Limnpea crawls over
the bottom, up the stalks of
aquatic plants, and 011 the sur-
face film of water. During-
FIG. loo. — Left. Physa hetcro-

stropha, the left-handed pond drought it burrows into the
snail Right Limn^a, the right- d d j tj t f

handed pond snail, with the

apex eroded off as is usually the the shell.

Physa2 has a smaller, rela-
tively stouter shell than Lini-

, and one whose coil is left-handed (Fig. 153). It
lives in even the smaller ponds and brooks, and may be
easily reared in aquaria. It feeds freely
upon any kind of vegetable matter.
Pliysa lieterostropha is the common species
of the United States (Fig. 153, left).

Planorbis8 is coiled in one plane like a
watch spring1.4 It lives in a similar ,,

FIG. Io4. — Planorbis,

habitat with Physa. A great many the Mat-coiled pond
species are distinguished which vary con- pj^jto bvWHcTp
siderably in size. Snails of this genus
likewise are easily kept in the aquarium, and lay numerous

case in adult shells. Nat. size.
Photo, by W.H.C.P.

1 From Xt/x^Tj, a marsh.

2 00cra, bellows.

s planus, flat ; orbix, circle.

Fig. 154.

THE SLUG AXD ITS ALLIES 1(37

eggs encased in gelatinous envelopes adhering to the
glass.

Of the shells of marine gastropods, which are favorite
objects in collections because of their beauty and per-
manence, only a few types can be mentioned.

Littorina 1 is an example of the entire-mouthed proso-
branchs. The commonest form at most parts of the shore-
line north of New York at the present time is Littorina2
littorea.2 This is knoAvn in England
as the periwinkle, and is there used as
food. As its systematic name implies,
it occurs on the seashore, which it
often crowds so as to force all other
species from it. It occurs north to
Greenland, and on the northwestern
European coast. It has not always FIG. 155. — Littorina ut-
occupied our shores, but has been £Tf !he sh£re tsnf '

Nat. size. Photo, by

migrating southward. In 1855 Lit- w. H. c. P.
torina \vas found in the Gulf of
St. Lawrence ; in 1869 it was stated to occur in Halifax ;
in 1870 a few individuals were found on the Maine coast ;
during 1871 the species occurred on the New Hampshire
coast ; in 1872 one specimen was found at Salem, Massa-
chusetts ; in 1875 the first two specimens were taken at
Woods Hole, Massachusetts, south of Cape Cod ; in 1880
the first specimen was taken at New Haven; in 1891 it
occurred as far south as Delaware Bay. Yet at the present
time it is not very abundant at Cold Spring Harbor, near
the western end of Long Island Sound. Persons who live
on the coast south of Cape Cod would do well to note care-
fully the abundance of the species on their part of the

1 Fig. 155. 2 From littus, the seashore,

168

ZOOLOGY

tia) her os.
nat. size.
W. H. C. P.

Two-thirds
Photo, by

shore-line. Besides littorea there are two species of
Littorina which were on our coast when records first
began to be made. The species
may be distinguished by the circum-
stances that L. littorea has a black
head and a heavy shell of brown or
olive color. L. rudis l is smaller, has
an angle at the apex of 60° to 70°,
and its shell varies in color from
white to red. L. palliata2 has an FlG m.- Natica (Luna-
apical angle of 95°, and a shell
varying from white to orange, slate,
or brown.

Natica is another common species with an entire mouth.
It can be at once distinguished from Littorina by the

" umbilicus," or depression situated at
the left of the mouth and in the axis of
the shell (Fig. 156). In the living
animal the shell is often quite envel-
oped by the large fleshy foot. The
members of this genus lay their eggs
in spiral " collars ' made of aggluti-
nated sand. These are common objects
of the seashore.

Fulgur 3 is a good example of a
prosobranch having a canaliculated
shell. The canal exists for the pur-

r (Sycotypus) cani- Pose of containing the siphon ^ by
culatus, one of the which water is brought to the animal

Fasiolaridse. One- ,. . -. . -, T^ ,

fourth nat. size. Photo, as it lies buried in the sand, bulgur
by w. H. c. P. is OU1. largest common gastropod. Its

1 Hough, rude, 2 A cloak. 3 Lightning-.

FIG. 157. — Shell of Ful-

777 A; HLUG AND ITS ALLIES

IfW

shell is about 150 millimetres long, and pear-shaped. In

one species the margins of the whorls are grooved (Fig.

157) ; in the other they are carried out

into thorns. The egg-cases are tough

and membranaceous and resemble rows

of coin strung on a string, the whole

being slightly coiled.

In Urosalpinx 1 the canal is short (Fig.
158). This typical representative of the
Muricidse is everywhere abundant on our
Eastern coast. It is much hated by

«/

oystermen, by whom it is known as the

"oyster drill." It bores through the FIG. 158 - - Urosal-

J pinx, the oyster

shell of this and other bivalves bv means

of its radula and sucks out the contents
through the hole.

Crepidula,2 the boat shell or " decker," represents a
type in which the spire has become almost obsolete. It is

drill. Nat. size.
Photo, by W. H.
C. P.

FIG. 15U. — Crepidula, the boat shell. Two-thirds nat. size. Photo, by

W. H. C. P.

still represented, however, in a rudimentary way at the left
of the aperture (Fig. 159). The modified shape is associated
with the habit the mollusk has of lying, aperture down-

1 ovpd, tail ; adXiriy^ a trumpet. - A small sandal (crepidcC).

170

ZOOLOGY

m.e

~nu

ward, close to the rock or another shell. By this means
the animal is better protected. The "deck'' is a plate

which has been de-
veloped internally to
help hold the animal
in the shell.

The limpets are
modified prosobranchs.
They are bilaterally
symmetrical, and are
covered by a flat, coni-
cal shell, which is ap-
plied closely to the rock
all around the base in
such a way as to pro-
tect the animal within.
In some species (genus

* ISSUrella a) there IS an

lamellse; m.e, edge of the mantle; mu, at- opening" at the apex of
tachment muscle; si, slits in the attachment

muscle; sh, shell; v, efferent branchial the shell through which
vessel ; V aorta -,ve .smaller vessels. From th t { expelled

the " Cambridge Natural History."

which has passed over

the gills, Our common Eastern rock limpet is not per-
forated; it is known as Acmcea.2 In Europe, limpets
(Patella, Fig. 160) are used as food ; but on our Eastern
coast they are too rare for this.

The opisthobranch mollusks include a large proportion of
symmetrical shell-less species. The most familiar of these
are the nudibranchs. They may be found among hydroids
hanging from rocks, or in tide-pools. Our species are
usually less than 20 millimetres long. They are often

1 A little slit or fissure. '2 d/c/mtoj, in full bloom, maturity.

FIG. 160. — Patella vulgata, seen from the
ventral side. /, foot ; y.l, circlet of gill

THE SLUG AND ITS ALLIES

171

covered with numerous gills, which give them a velvety
aspect. When placed in an aquarium, they lay eggs in
gelatinous coils on the hydroid stems. Eolis l is a com-
mon genus (Fig. 161 J.

Besides the gastropods, two groups of mollusks may be
briefly mentioned here. In one group the body is very

symmetrical, not only

externally, but also

internally, which is

not true of most

symmetrical gastro- FIG. 102. - chiton

FIG. 161- "Eolis (Cra- d A common (Trachydermon)

turn), a nudibranch. apieulatux, the ar-

Nat. size. Photo, of representative IS Chi- madillo snail. Nat

living animal by W. H. ^ 2 (Fig> 162) _ Thig ^ ^Photo. by

animal has a sort of

coat of mail, since its shell is made up of eight pieces,
lying one behind the other, along its back. When removed
from the rock or shell on which it rests, it coils up like a
pill-bug or armadillo.

Coordinate with the Gastropoda is the group of Cepha-
lopoda.3 In this group belong the squids and cuttlefishes.
They have a large, distinct head, a circle of arms about the
mouth, a funnel-shaped foot, and huge eyes on each side of
the head (Fig. 163). The squids are the best-known cephal-
opods, since they travel in schools in our harbors and are
often cast upon the shore after a storm. They can also be
obtained in the markets of our coastwise cities, since their
flesh is used to a certain extent as food. Cuttlefishes,

1 Eolis, daughter of Eolus, the god of the winds.
~ xircji', coat, case, covering.

3 Ke(pa\r), head ; TTOI/S, foot ; because the arms or foot are placed around
the mouth.

172

ZOOLOGY

best known from their "bones" or rudimentary shells

embedded in the mantle, are inhabitants of deeper

waters. They have shorter bodies
than the squids, and their arms are
eight in number instead of ten
as in the case of the squids. In both
groups locomotion is effected by the
reaction to a stream of water which
is taken into the mantle chamber
at the edges of the mantle and
is forced out through the " funnel,"
which lies between the eyes in Fig.
1(33.

The shell is rudimentary in both
the squids and the cuttlefishes, and
like that of the slug is embedded in
the mantle. Even in Spirilla the
shell, though coiled and containing a
siphon, is completely covered by the
skin of the animal. There are two liv-
ing genera of Cephalopoda which have
an external shell. One is an ally of

FIG. iitt. — L<jiit/<j Peaia, the cuttlefishes — the paper nautilus

eastern squid. One-third t ^ii'i--C i • n

nat. size. From Rathbim. O1> Argonauta? which IS found in all

tropical seas. The other is the sole

survivor of a once abundant group. This is the Pearly
Nautilus of the Indian and Pacific oceans. Its shell is di-
vided into water-tight compartments, in the last formed
of which the animal lies. It keeps its attachment to
the shell by means of a central strand of tissue — the
siphon (Fig. 164, s). Allied to the Nautilus is the huge

a sailor in the Argo.

THE SLUG AND ITS ALLIES

173

family of Ammonites, of which two thousand species are
known, ranging from the Silurian up to the Cretaceous
formations.

FIG. 164. — Nautilus pompilius, the Pearly Nautilus. Median section, c, outer-
most chamber whose bottom is formed by the septum, tie ; s, siphon travers-
ing all compartments ; ?,eye; h, hood; rn, part of mantle, reflected over
the shell ; /, lobes enclosing tentacles (t) ; si, incomplete funnel ; mu, shell
muscle ; n, gland secreting the capsules for eggs. After Owen.

174

ZOOLOGY

APPENDIX TO CHAPTER XI

Spirulidw

VermetidcB

KEY TO THE PRINCIPAL FAMILIES OF MARIXE-SHELLED
GASTROPODS OF THE ATLANTIC COAST OF THE UNITED
STATES, ADAPTED FROM A. C. APGAR

a i. Shell spiral, of one to many whorls.

61. Spire in a single plane, and whorls not in con-
tact. [A cephalopod shell ; liable to be
mistaken for a gastropod-shell, page 172]
bo. Spire dextral.

Ci. Operculated ; aperture not over \ area of

shell.

d\. Anterior margin of aperture entire.
€i. Shell tubular ; spiral at apex,
irregularly twisted near aper-
ture .....
e>2. Shell regularly spiral, elongated ;
width less than 1 length ;
whorls 5 or more ; angle of
spire less than 45° ; aperture
less than ^ length of shell,
/i. Whorls rounded , almost sepa-
rated, crossed by elevated
longitudinal ribs ; aperture
oval ; lip continuous ; our
species over 10 mm. long .
/2. Whorls about 5; minute shell,
less than 5 mm. long ; width
about | length ; aperture
about i length ; apex blunt
/3. Whorls 5-10 ; shells elon-
gated, conical, turreted ;
aperture ^-| ; length of
shell of our species 4-10
mm. long ....
63. Shell regularly spiral, shortened ;
width nearly as great as or
greater than length ; whorls

ScalariidcB

Rissoidce

Pyramidellidce

APPENDIX TO CHAPTER XI

175

usually few ; angle of spire
always over 50°, usually over
90° ; aperture over \ length of
shell.

/i. Shell conical, pearly under
epidermis and within aper-
ture, usually brilliantly so ;
umbilicus deep and large .
/2. Shell globular or oval ; spire
short, body whorl large ;
umbilicus rounded, dis-
tinct, either free or covered
by a callus ; angle of spire
90° or more

/a. Shell top-shaped to globular ;
interior pearly, 8-30 mm.
long ; umbilicus when pres-
ent not rounded nor cov-
ered with a callus .

/4. Shell minute, nearly disk-
shaped, widely umbilicated
Anterior margin of aperture notched

or produced into a canal.
e\. Shell with canal formed by a de-
cided prolongation of anterior
end.

/i. Large, heavy shells, over 100
mm. long, pear-shaped ;
whorls angulated or nodu-
lous

/2. Rather thin shells, 20-80 mm.
long, ovate to pear-shaped ;
whorls rounded and cov-
ered with 40-00 small re-
volving ridges . .

/s. Shells over 20 mm. long, with
longitudinal, rib-like undu-
lations crossed by revolving
lines .

Trochidcv

Naticidae

(Ex. Natica)

Littorinidce

(Ex. Littorina)
Adeorbidce

Fasciolariidce

(Ex. Fulgur)

Bwcinidce

Muricidw
(Ex. Urosalpinx)

176

ZOOLOGY

/4. Shells less than 20 mm. long ;
aperture with a notch near
posterior end, formed by
outer lip not squarely meet-
ing body wall .

fr,. Shells less than 15 mm. long ;
aperture entire at posterior
end ; narrow, and a little
less than -J the length of
the shell ; canal rather
short . .*

e-2. Canal short or absent ; aperture

notched,
/i. Shells large, 40 mm. or more

long ; whorls rounded
/2. Shells 20-40 mm. long;

whorls rounded

/3. Whorls flattened, surface
usually beaded ; aperture
over i length of shell

Co. Non-operculated, or operculum very mi-
nute ; aperture with neither a canal
nor a notch at anterior end.
(I i. Aperture over f area and f length of
shell ; spire distinct, pointed ; shell
ear-shaped .....
(?o. Aperture \ the area or more, and the

full length of the shell.
Ci. Shell with 1 whorl, less than 2
mm. long ....
?o. Shell with several whorls, under

4 mm. long ; spire flat .
e-s. Several whorls, a pit in place of

spire, over 6 mm. long .
t?s. Aperture less than ^ the area of the

shell.

e\. Aperture | to whole length of
shell ; spire distinct, usually
flattened ; under lip with single
fold or smooth

Plwirotnmidce

Columbellidce

Philinidce,
Scaphandridce

Bull idee

TornatinidoB

APPENDIX TO CHAPTEE XI

177

?2. Aperture i-f length of shell ;
under lip with 2 or more teeth

c3. Non-operculated ; aperture with canal at
anterior end ; our species 20 mm. or

less long

b3. Sinistral ; whorls in contact.

<"i. Shell ovate-globose, small, not over 5 mm.
long, transparent .....
c.2. Shell elongated, turreted, slender, less
than oO mm. long. ....
GS. Shell large, over 100 mm. long, with pro-
duced anterior canal .
a-2. Shell flat, boat or cup shaped, if somewhat spiral,

not forming a complete whorl.
bi. Shell with apex somewhat spiral and an in-
ternal, usually horizontal, partition or dia-
phragm

fto. Shell conical or cup-shaped, with apex turned

forward ; no shelf or partition.
GI. No perforation at apex or notch in mar-

gin

c-2. Apex recurved ; margin or apex perfo-
rated . . > . . .

Auriculidce

(Kx. Mt'lunipiis)

Triforidce

Calyptrwidce

(Ex. Crepidiila)

Acmceidce

(Limpets)

Fissurellidce

CHAPTER XII

THE FRESH-WATER CLAM AND ITS ALLIES

THE fresh-water clams belong to the group of lamelli-
branch mollusks, characterized by the absence of a distinct
head, by the possession of leaf-like gills on the sides of the
body, and by the presence of a calcareous shell composed
of a right and a left valve. Economically this group is the
most important to man of all Mollusca. It includes both
marine and fresh-water species. About six thousand
species of living lamellibranchs and over ten thousand
fossil species are recognized. They all fall into two prin-
cipal subdivisions. The first (Siphonata) includes species
which possess a siphon and have the mantle edges grown
together, while the second (Asiphonata) has no siphon and
has the mantle lobes for the most part wholly separated.1

Anodonta and Unio are extremely common in the ponds,
lakes, and rivers of North America. Anodonta is more
apt to be found in still waters and Unio in running
waters. They lie partly buried in the mud of the bottom,
with the valves of the shell gaping open and the partly
united edges of the mantle protruding. They do not lead
wholly sedentary lives, but may burrow or plough along
the bottom.

Their food is gained from organic particles borne along

1 A key to the principal families of bivalve shells will be found in the
Appendix, p. 188.

178

THE FRESH-WATER CLAM AND ITS ALLIES 179

in the current of the water. A part of this current is
carried through the mantle chamber and forced out again,
deprived of usable food and of the oxygen used in respira-
tion. By devouring organic matter these clams act as
useful scavengers of the water.

The family of Unionidae, to which Unio and Anodontia
belong, is of world-wicte distribution, but nowhere else are
Unionidre so numerous as in the United States. They
show in our country a most marvellous variability also, so
that hundreds of kinds have been described from our waters.
The extraordinary abundance of Unios in North America
is due to the fact that nowhere else is there such a large
area of soluble limestone as in our Mississippi valley. The
clams take from the water the lime which they use in the
construction of their shells, change it into an insoluble
form, and thereby advantageously reduce the amount of
the inorganic matter in solution, for this change in the
quality of the water renders it more fit to drink and to
sustain other animal and plant life.

Although numerous and of large size, the Unionidae do
not seem to be much used as human food. The aborigines,
however, made use of them, as the great shell-heaps on the
banks of rivers of the Ohio valley testify. They yield
also pearls, which occasionally, especially in the Ohio
valley, are of precious quality. Even the small, imperfect
pearls are of value, since they are ground up to make the
powder used in polishing the more valuable pearls.

The spawning season of our Unioimhe is short. The
eggs pass, during the latter part of October, into the gills
of the parent, where they undergo their early development,
protected by the parent shell and supplied richly with
oxygen. The cleavage is unequal because of the larger

180

ZOOLOGY

amount of yolk in some of the cells than in the others.
Eventually a shell is formed, which divides into two valves
united by a straight hinge. A spine is formed on the free
edge of each valve, and a thread (byssus thread) is secreted
from the body. The young at this stage is known as
Glochidium (Fig. 165). In the spring Glochidia become
free from the mother, and attach themselves to the gills or
fins of a fish by means of the spines on the shells. Here
they become transformed. The single adductor muscle dis-
appears, and becomes replaced by the two characteristic of

' R B. J.

TD. --

FIG. Ki"). — A, advanced embryo of Anodonta: B, free glochidium. /, pro-
visional byssus ; s, sbell ; .s7t, books ; .sm, adductor muscle ; so, sense organs ;
w, cilia. From Korschelt and Heider's " Embryology."

the adult; the gills arise, the shell gains its adult char-
acter, and becomes free from the fish on which it has lived
temporarily as a parasite.

There are other species of fresh-water lamellibranchs
besides the Unionidae. These belong to the Cycladidae,
allies of the marine Cardidre or Veneridre. They have
much the shape of our common hard-shell clam of the sea,
but are much smaller in size, rarely exceeding 15 milli-
metres. Cyclas (or Sphserium) is of world-wide distribu-

THE FRESH-WATER CLAM AND ITS ALLIES 181

tion, but it is especially abundant in North America. It
occurs in ditches, ponds, and rivers
of New England, as well as in the
South and West Some species of
it inhabit brackish water. Pisidium
has both valves unsymmetrical. Its
species are still smaller than those
of Cyclas, rarely exceeding 10 milli-
metres. It likewise is found in
ditches, ponds, and streams all over
our country.

The remaining families which
we shall consider come from the
sea, and all occur on our Eastern
coast.

The Pholadidae1 and Teredidae2
include certain wood and rock-
boring species, which do great
damage by boring into wooden
vessels and pilings (Fig. 1(3(3). In
such locations they are commonly
called ship-worms. The boring is
done by the movements of the
shell, combined with the action
of the muscles and foot. The
only thing which seems effectively
to stop these mollusks from boring
into wood is iron rust, so that piles
driven full of nails are apt not to FKJ. KM;.— TV/WO ncpali*,

11-1 in a piece of timber. /'.

be attacked. paUe£. SjSt siph,,lls: T,

tube; V, valves of shell.

1 0oAds, Greek name for a boring mussel. From the " Cambridge

2 repe'w, to bore. Natural History."

182 ZOOLOGY

The Solenidse1 include the "razor-shell" (Fig. 167).
This animal, like the shell, is elongated and subcylindrical.
By means of its foot, which can be protruded between the

FIG. 167. — Emis direct us. Young. Nat. size. Photo, by W. H. C. P,

\alves, it excavates, with great rapidity, a hole in the sand
or mud, into which it draws itself. These mollusks are
sometimes used for food, but it is not easy to get them in
quantity.

The Mactridae2 include species commonly known in the
North as hen-clams and surf-clams. They are more ellip-
tical and larger than the common hard-shelled clam or " quo-
hog," and have a proportionately lighter shell (Fig. 168).
They are not often used as food because they become very
tough when cooked.

The Myidae3 include the common clam of New England,
Mya arenaria, abundant along our whole Eastern coast and
used as food chiefly in New England. These clams occur
in great numbers in every mud-flat. Their great siphon is
extended at high tide to the surface of the ground, so as to
take in and throw out water (Fig. 169) ; but at low tide it is
retracted, and the clam lies invisible in its burrow. This
clam was much prized by the Indians, as the great, ancient
shell-heaps along the coast testify. In 1892 the clam com-

, a channel or tube. 2 /xd/crpa, a baking-trough.

3 fj.va, Greek name for a kind of mussel.

THE FRESH- \VATER CLAM AND ITS ALLIES 183

merce for New England was estimated to be worth nearly
half a million dollars.

FIG. Iti8. — Mactra solMisshna, the Eastern hen clam. Nat. size. From

Gould-Binney.

The Veneridae l include the hard-shelled clam or u fjiio-
hog " of the Indians. Venus mercenaria is the commonest
species, and is most abundant south of Cape Cod. It owes

FIG. 1G9. — My a arenaria, the New England " clam." At the left the foot is
seen ; at the right, the siphon. One-half nat. size. From Yerrill. " Inverte-
brates of Vineyard Sound."

1 Venus, the goddess of love.

184

ZOOLOGY

its name " mercenaria " to the fact that the purple-colored
patch seen on the margin of the shell was used as money

FIG. 170. — I'e/ias mei\"jiuifi<i, the hard-shelled clam. At the left the foot
protrudes from the shell ; at the ri^ht the siphons. Nat. size. From Verrill,
" Invertebrates of Vineyard Sound."

( " wampum ") by the Indians. The shell is extremely heavy,
and usually nearly circular in outline (Fig. 170).

The Arcidae 1 and their allies include several species hav-
ing a more or less elongated
hinge - joint crowded with
many small teeth. Our com-
mon Eastern species (Area
pe.rala, Fig. 171) has bright
red blood and is commonly
known as the " bloody clam."
The Mytilidae 2 include

Fi(i. 171. — Arcapexatu, the bloody

clam. Nat. size. Photo, by the mussels, which are the

W. H. C. P.

1 area, an ark.

2 /xirri'Xos, an edible mussel of the Greeks.

THE FREtiH-WATER CLAM AND 77'N ALLIED 185

familiar blue-black, wedge-shaped shells attached in clus-
ters or beds to rocks near low tide (Fig. 17:2). They are
edible. In France they are reared for the market on
woven nets, which are submerged at each tide.

FIG. 172. — A bed of Modiola, the horse-mussel, ou a mud-bank. Photo, by

W. H. C. P.

The Aviculidae l are a group closely allied to the last, but
not represented, on our shores. It is important because
mollusks of this family produce the best pearls. Pearl-
lishing has been carried on since the earliest preserved
historic records. The pearl banks of Ceylon are known

1 A small bird (acts).

186

ZOOLOGY

to have been fished for two thousand years. The finest
pearls come from the Persian Gulf. They are gathered
there by native divers, who, after taking several deep
inspirations, either dive down unaided or descend upon
weighted ropes. When they can no longer remain under
water, they either ascend again unaided or are rapidly
drawn up to the boats above. The pearl oysters brought
up to the surface are then examined for pearls. The pearl
is the secretion of the oyster about a small foreign body,

such as a grain of sand.
This secretion prevents the
irritant from injuring the
tissues. It is of the same
nature as the substance lin-
ing the shell. The latter
is the mother of pearl of
commerce, and is used for
knife handles, buttons, and
the like. The iridescence

FIG. 173. —Pectenirradians, scallop, is not due to the chemical

left or upper valve. Nat. size, composition of the secreted

Photo, by AV. H. C. P.

substance, but to the fact

that it is deposited so as to leave fine lines on the surface
which diffract the light.

The Pectinidae l include the scallop-shells. These occur
along our whole coast. They live in shallow water, and
are capable of rapid movement in the water by clapping
the valves. The adductor muscle of the valves alone is
eaten by man. The common species is Pecten irradians.
It varies greatly in color, from bluish to reddish and
orange (Fig. 173).

1 pecten, coinb.

THE FUEMl-WATER CLAM AND ITS ALLIES 187

The Ledidae include certain elongated shells with a
shiny epidermis, and a large number of teeth on the hinge,
which are found chiefly in mud in rather deep water.
The animal has a large foot
(Fig. 174) with which it bur-
rows rapidly. It can also
move rapidly through the
water as the scallops do.

The Ostreidae : include the
oysters, which are the most
important invertebrate food
fishery, being valued at
twenty to thirty million dollars per year for our Atlantic
seaboard. Oysters are found on all coasts. Our Ostrea vir-
giniana2 extends from the Gulf of St. Lawrence to the Gulf
of Mexico. The o}rsters of our Western coast are not so
important as the Atlantic species. 0. edulis is the prin-

FKJ. 174. --Yoldia, one of the Le-
dida*. Foot protruding below.
Nat. size. Photo, by W. H. C. P.

FIG. 175. — Oxtrea virg/niarta, the Eastern oyster. One-third nat. size.

Photo, by W. H. C. P.

cipal European species. In Japan there is a species occa-
sionally gaining a length of three feet. The oyster
was formerly commoner and larger north of Cape Cod than

1 From Greek name for oyster.

2 Fig. 175.

188

ZOOLOGY

it is now, for the great aboriginal shell-heaps (*' Kitchen-
middens ") of the New England coast contain shells of
enormous size. The cause of this gradual extinction of
the oyster is uncertain, but is believed to be due partly to
general climatic and geographic changes and partly to
over-iishiiip\

APPENDIX TO CHAPTER XII

KEY TO THE PRINCIPAL FAMILIES OF MARINE LAMELLIBKAN-
CHIATA OF THE EAST COAST OF THE UNITED STATES

ADAPTED FKOM A. C. APUAK

a\. Shell when closed at ventral side, gaping inure or

less at the ends.

bi. Without toothed hinge or proper ligament,
often with accessory valves ; no distinct epi-
dermis.

c'i. Length decidedly greater than height
Co. Length and height nearly equal ; shell
small .......

b-2- With proper hinge, often distinctly toothed

and with hinge ligament or pad.
t*i. Hinge with many small cardinal teeth in
each valve . .

c-2. Hinge of not over 4 cardinal teeth in

each valve.
di. Shells equivalve.

e\. Two or more times as long as
high, gaping more or less at

ends.
/i. Length '•> to-0 times height ;

epidermis polished ; um-
bones not over one-quar-
ter from anterior end

Pholadidcc

7.eredid(e

(Shipworms)

Ledidce

(Ex. Y old in)

Solenidce

(Uazor Clatus)

APPENDIX TO CHAPTER Xll

189

/:>. Shell thin, rounded in front,
narrowed and gaping be-
hind, cartilage pit shal-
low ; external ligament
short ....
Shells inequivalve.
e\. Length and height about equal,
e-2. Length decidedly greater than

height.

/!. Over 25 mm. long ; right
valve nearly flat ; whole
shell compressed to one-
sixth length .

/2. Over 50 mm. long ; 'slightly
inequivalve ; no external
ligament; internal car-
tilage on spoon -shaped
process of left valve

f.2. Length about 3 times

height ; umbones central, Psammoliidfc
fs. Length less than 3 times

height ; surface covered

with radial ridges, chalky

white, umbones near an-
terior end
/4. Length about 2 times

height; epidermis

polished, with notched

border extending beyond

the edge of the thin shell,
/4. Shell with thick black

epidermis ; external liga-
ment prominent and on

shorter end of the shell,
e». Length less than twice height.
J\. Shell somewhat triangular,

with internal cartilage

between deep triangular

pits, similar in each

valve

Solrmyidw

SaxicctvhUv

Mactridce

(1 leu Clams)

Pmidoriflre

190

ZOOLOGY

/3. Shell under 18 mm. ; promi-
nent external ligament,
«2. Shell not at all gaping

bi. With not over 3 cardinal teeth in each valve.
t'i. Valves equal in size, curvature, and

markings.

di. Anterior muscular impression very
small, hinder large; shell elongated,
mussel-shaped ; umbo at or near
posterior end ....

d». Hinge line straight, formed by ears
at sides of umbo, radiating ribs,
scalloped edge ....

d$. Height and length nearly equal ; a
decided pallial sinus

(Hi

d±. Height and length nearly equal ; no
distinct pallial sinus, at most a
mere undulation of pallial line at
posterior end.

f\. With a plain lunule in front of
umbones; without radial
ribs.
fi. Over 20 mm. long, com-

«/ *• O 7

pressed , ligament external
/_». Shell somewhat quadrant
shaped; less than 8 mm.
long; surface with con-
centric ridges.

/s. Shell less than 5 mm. long,
very much compressed ;
ends rounded .

e2. With no lunule and with dis-
tinct radial ribs .
Co. Valves unsymmetrical.

(?i. 2 muscular impressions, a distinct

pallial sinus. (See t?2 under «!.)
d». 1 muscular impression ; height never
much less than length

Tellinidce

Mytilidce

(Mussels)

Pectinidce

(Scallops)

Veneridce

inl-shelled Clams)

As t art i < he

Crassatellidce

ErycinidcK
Oardiidce

APPENDIX TO CHAPTER XII

191

€]_. Fixed mollusks with large rough
shells attached by large valves,

€'2- Fixed mollusks, with their pearly
shells attached by smaller
valve which is flat or concave
and perforated or notched

e*. Free mollusks ; hinge line

straight, formed by ears at

sides of umbo ; with radial

ribs .....

With many small cardinal teeth in each valve.

Ci. With distinct radiating ribs ; shell over

30 mm. long

Co. Smooth, length and height equal ; under
12 mm. long

c3. Elongated shells, length nearly or twice
height ; a pallial sinus ....

Ostreidce

(Oysters)

Anomiidce

(Jingle shells)

Pectinidce

ArcidoK

(Ark-shells)

NucnlidcK
Ledidce

KEY TO THE PRINCIPAL GENERA OF FRESH-WATER LAMELLI-

BRANCHIATA

«i. Siphonate ; without marked muscular impression,

Fain. Cycladidce
bi. Valves sub-symmetrical ..... Genus Cyclas

b>2- Valves unsymmetrical ; siphons united . • . Pisidium

cto. Asiphonate ; with two muscular impressions . Fain. Unionidw
l)\. Hinge with teeth.

Ci. With short cardinal teeth and long lateral

teeth ....... Unio

Co. With short cardinal teeth and no lateral

teeth ....... Maryaritana

Hinge without teeth, or with only a small ridge, Anodonta

CHAPTER XIII

THE STARFISH AND ITS ALLIES

Systematic Position. — The starfishes belong to the
group of Echinodermata,1 characterized by a radial, usually
five-rayed, structure, a more or less well-developed system
of calcareous plates in the skin ; a system of water-tubes,
which is used by the movable forms for locomotion; and
the separation of the intestine from the body cavity.

Distribution and Habitat. — The common pink starfish of
the eastern United States (Asterias2 vulc/aris3) ranges
from Labrador to northern Florida. A dark brown form,
sometimes called Asterias Forbesii^ is recognized by some
authors as a separate species inhabiting the coast from
Massachusetts Bay southward. Our shore starfish extends
out into fairly deep water, but is not abundant at greater
depths than 60 fathoms. In Long Island Sound it is
found especially on. the oyster beds, where it is very
destructive. On rocky coasts starfishes will be found in
crevices of the rock or in tide-pools. They love cool
waters, and are often found hanging on vertical walls or
ledges. Upon reaching the surface of quiet water, they
may extend one or more of their arms out upon the under
side of the surface film.

hedgehog, sea-urchin ; Se'p/xa, skin. A key to the principal
classes of Echinodermata will be found in the Appendix to this Chapter.
- dcrT^p, star ; dtrrepias, starred.

3 Common. 4 Of Forbes, an English zoologist.

102

THE STARFISH AND ITS ALLIES 193

Food. - -The favorite food of the starfish is some kind of
mollusk, especially bivalves, such as mussels and oysters.
Their method of feeding is as follows: They crawl over
the bivalve, arch the body over it, apparently pull open
the valves, then turn the stomach inside out over the soft
body within the shell, and gradually digest it. The star-
fish probably finds its food by means of a keen chemical
sense.

Starfishes are of economic importance on account of their
destructiveness to oysters, but since the oystermen have
learned to keep the beds clear of starfishes and that tear-
ing starfishes into pieces only aids in their increase, as
each piece produces a whole starfish, the damage wrought
by starfishes must be less than it was formerly.

Development. - - Starfishes have the sexes distinct ; and
the sex can usually be told by the color. The female has
a more bluish tint, while the males are of a reddish brown
color. Both the eggs and sperm are extruded into the
water through small openings on the aboral surface at the
interspace between two adjacent arms. The egg is hardly
visible to the naked eye, and is enclosed in a delicate
membrane. The egg undergoes cleavage ; that is to say,
the single sphere breaks up into two, four, eight, sixteen
spheres, and so on. Finally a hollow ball, made up of
these spheres or cells, is formed, called the "blastula."
Next the wall of this hollow sphere is pushed in at one
side, forming a sort of cup with two walls. This is the
so-called "gastrula." The cavity of this cup is the
digestive cavity. At first it is a sac with only one
opening, but later a second opening, the true mouth,
breaks through, and the former opening persists as the
anus. Pairs of arms, edged with cilia, now bud out on
o

194 ZOOLOGY

each side of the body, and the larva becomes bilaterally
symmetrical.1 Meanwhile, inside the body, the system
of water tubes of the adult starfish has begun to form,
and finally, over the stomach on the left side, five main
water tubes, radially arranged, make their appearance ;
these are the five radial tubes, one of which runs down
each future arm.2 On the right side of the stomach, calca-
reous plates are laid down to form the aboral wall of the
starfish.3 The young star is now found as a parasite at the
hinder end of the larva. Soon all the front end of the larva,
together with the long arms, becomes absorbed. Up to
this stage the larva lias been free-swimming, but it now
settles to the bottom. There the process of resorption is
completed, the upper and lower surfaces of the star
approach each other, the calcareous skeleton and sucking-
feet rapidly develop. At this stage the disk is so large,
and the arms so short, that the young starfish looks more
like a sea-urchin than an adult starfish. The elongated
arms and the pedicellarue of the adult are not gained until
three years have passed.

t/ -*-

1 Figs. 176 and 177. 2 Fig. 178. Fig. 179, ab>.

FIG. 176-179. — Larval stages and metamorphosis of starfish. After drawings
of E. B. Wilson, from Brooks, " Invertebrate Zoology."

FIG. 176. — Dorsal view of starfish larva with beginnings of ciliated arms.

FIG. 177. — Ventral view of same larva.

FIG. 178. — Side view of an older larva in which young star is beginning to
arise.

FIG. 179. —Ventral view of same larva, a, anterior end ; b, posterior end;
1-4- , ciliated projections; a', preoral arms; a HI, oral surface of young star
with beginning water tubes, am-am5; ab, ub', ab^, aboral surface of star;
c, postoral arm ; i, intestine; m, mouth; n, lateral arm ; o,anus; ce, oesopha-
gus; q, q', dorsal lateral arms; *, stomach; ww', water tubes ; am, Fig. 177.
region from which water tubes arise.

FIG. 17ti.

FIG. 177.

FIG. 179.

195

196

ZOOLOGY

Abnormalities are frequently found among starfishes, —

partly on account of their
capacity for regeneration,
even from the disk and a
single arm. Thus one may
find a starfish with three or
four rays, or with a small
ray interpellated in be-
tween normal-sized ones.
Not all abnormalities seem
to be the result of mutila-
tion, however; for example,
sometimes two arms seem

FIG. 180. — Abnormal starfish (Astenas),
apparently produced by fusion of two to be fused (Fig. 180).

r°Thalf nat- size> Phot°* by Other Starfishes. — Aste-

. \j, -T.

FIG. 181. — Ct'ibrella sanguinolenta. Nat. size. From Leuuis.

THE STARFISH AND ITS ALLIES

197

rias vulgaris belongs to the gionpAsteroidea.1 But there are
over five hundred other species of starfishes. In some of
these — as in Asterias — the skele
tal plates of the skin make a net
work ; in others they
form a solid calcare-
ous covering. To the
first class belong, besides
Asterias vulgaris, Aste-
rias ocliraceaf which oc-
curs commonly on the
Pacific coast from Sitka,
Alaska, to San Diego,
California. This has a
much thicker, more

solid skin than the FIG. 182. — Solaster, a multirayed starfish.

t ,-, , . . A Reduced. From Leunis.

Atlantic species. A. gi-

gantea^ attains a diam-
eter of over two feet.
Next to A. vulgaris,
our commonest Eastern
species is a smooth,
leathery, blood-red star-
fish, about 10 centi-
metres in d i a m e t e r,

called Oribrella 4 san-

1 APT-TIP, star ; eTSos, form.

2 o>x/>6s, pale yellow.

3 giyanteus, gigantic. This
species occurs on our Pacific

FIG. 183. — Archiaster, a webbed starfish. coast.
Slightly reduced. Photo, by W.H.C.P. 4 cribrum, sieve,

ZOOLOGY

guinolenta1 (Fig. 181). Certain starfishes have many
arms instead of only five, as in the case of Solaster 2 endeca 3
of the northern Atlantic (Fig. 182). In still other star-
fishes the rays are partially connected by a membrane like
the web of a duck's foot, so that the whole outline is
nearly pentagonal (Fig. 183).

The Ophiuroidea. — In the Ophiuroidea 4 the organs are
not prolonged from the disk into the arms, consequently

FIG. 184. — Amphlura squamata. One of the Ophiuridae. Nat. size.

Photo, by W. H. C. P.

the arms may be thrown off without injury to the animal ;
hence the name "brittle-star." The brittle-stars fall
into two groups, in one of which, the serpent-stars, the
arms are uiibranched, while in the other, the "basket-
fish," the arms are branched.

Of the serpent-stars there are two common forms on the
New England coast,- -a Avhite species, with long, slender
arms, Amphiurab squamata 6 (Fig. 184), and the spotted
Ophiopholis,7 which has shorter, stouter arms. The

1 Blood-red. 5 dfjL<pl< round about ; ovpd, tail.

2 sol, sun ; aster, star. 6 Scaled (squama, a scale).
8 ej>5e/ca, eleven. 7 60is, snake ; 0oXi':, scale.

4 50ts, serpent ; ovpd, tail.

THE STARFISH AXD ITS ALLIES

199

animals live in crevices of the rock, and being of rather
small size, are not commonly seen. At the base of the arms,
on the right and left, are a pair of slits, which form the
exits from pouches into which the reproductive glands
open. In certain species the pouches are used for brood-
ing the young. The basket-fish occur in Northeastern

FKJ. 185. — Strongylocentrotus, the Eastern green sea-urchin, with tube feet
extended. From " Standard Natural History."

waters, from low tide to one hundred fathoms, and are
often brought up by fishermen, to whose lines they have a
habit of clinging. The branching of the arms enables the
animal to hold its prey, which consists of shrimp and fish.
The Echinoids, or sea-urchins, may be regarded as star-
fishes in which the arms have shortened and the disk en-
larged so as to fill up the interspaces, and make a solid,

200

ZOOLOGY

nearly spherical form. The sea-urchins eat various small
animals, and get food also from small bits of organic matter
in the mud which they swallow. They live more concealed
than the starfish, for some burrow in the mud and others
-such as our green sea-urchin of the Maine coast (Fig.
185) — grind out pockets in the rocks by means of their
spines. Others cover themselves with seaweed, and thus
become inconspicuous. Besides the green sea-urchin,

FIG. 186. — Arbacia, the Easteru black sea-urchin. Tube feet retracted. Nat.

size. Photo, by W. H. C. P.

which is found north of Cape Cod, we have a black sea-
urchin (Arbacia, Fig. 186), which extends south as far as
North Carolina. We have on the east coast also two kinds
of flat sea-urchins (sand-dollars), which live in the sand
from low water to one hundred fathoms. Their spines
are small and silky (Fig. 187). Some sea-urchins lose
their strictly radial form and become bilateral, having a
] jointed anterior end (Fig. 188).

THE STARFISH AND JT-S ALLIES

201

The Holothurians l may be likened to soft-skinned sea-
urchins, with the body drawn out to the form of a cucum-

FIG. 187. — Echinarachnius par ma,
the sand dollar. Spines removed
from left side. Nat. size. Photo,
by W. H. C. P.

FIG. 188. — Clypeaster, a bi-
lateral sea-urchin from the
West Indies. Spines partially
removed and surface rubbed
in patches. Reduced photo.

ber, or even of a worm. The calcareous skeleton is reduced
to small plates embedded in the skin. The mouth is sur-
rounded by a circle of tentacles.
The ambulacral feet are sometimes
absent. The Holothurians live in
sand and mud, often deeply buried,
and feed on small marine animals
or the decaying particles mingled
with the mud which they devour.
They are of considerable economic
importance. The members of one genus (Holothuria) is
taken in great numbers on the coral reefs of the Pacific

i v\o6ovpioi', a sort of water-polyp.

FIG. 189. — Caudina, the
tailed Holothuriau. a,
mouth; b, anus. After
Selenka.

£02

ZOOLOGY

FIG.

191. — Metacrinus interruptus.

After P. H. Carpenter.

FIG . 15 10. — »S'// » apt a inhe re tt s. a ,
tentacles; b, longitudinal mus-
cles; c, alimentary tract. -
After Quatrefages.

Ocean and the China
Sea, where they are com-
monly known as lk tre-
pangs." They are cut
open, washed, boiled,
dried, and sometimes
smoked. They are sold
in Chinese ports, and
some species are con-
sidered by Chinese epi-
cureans as great deli-
cacies. Several species of
Holothurians occur on
the Maine coast. A bar-
rel-shaped form with a

APPENDIX TO CHAPTER XIII 203

sort of tail (Caudina,1 Fig. 189) occurs on the Massa-
chusetts coast. A worm-like form, but with a beautifully
transparent skin (Synapta,2 Fig. 190), is found in sandy
beaches from Massachusetts to New Jersey.

The Crinoids,3 or sea-lilies, are familiar as fossils to resi-
dents of New York State and the Ohio and Mississippi
valleys. The living animals are less often seen, for they
are inhabitants of the deep sea. They have a cup-like
body, with the mouth at its centre directed upward, and
surrounded by tentacles (Fig. 191). The cup is either
borne on the end of a long stalk or is unstalked. The
former condition is more usual among the fossil species.

APPENDIX TO CHAPTER XIII

KKY TO THE PRINCIPAL CLASSES OF ECHINODEKMATA

«i. Sessile ; mouth turned upward ; body calyx-shaped Crinnidea

(Sea-lilies)

a-2- Not sessile.

b\. Body short ; skin hard, containing calcareous
plates ; mouth directed downward ; madre-
poric plate present.

Ci. Body with arms which carry a longitu-
dinal series of plates.

di. Arms with ventral furrow . . Axtcrnidea

(Starfish)
d2. Arms without ventral furrow . . Ophiuroidea

(Serpent stars)

1 cauda, tail.

2 awairrbs, fastened together ; from vvv, with, and ctTrrw, to fasten.

3 Kpivov, lily ; dSos, form.

204 ZOOLOGY

c%. Body without arms ; more or less spheri-
cal or cake-shaped .... Echinoidea

(Sea-urchins)

62. Body elongated ; skin soft, leathery, contain-
ing microscopic calcareous bodies ; madre-
poric plate absent ; mouth surrounded by

tentacles Holothuroidea

(Sea-cucuuibers)

CHAPTER XIV

THE HYDRA AND ITS ALLIES

HYDRA belongs to the group of Coelenterata,1 which
includes sponges, and certain organisms with nettling
capsules — Cnidaria.2 The Coelenterata have a more or
less radial form, and a system of internal cavities serving
for digestion as well as for body cavity.

The sponges are all sessile, have no nettling capsules,
have the body wall perforated by many fine incurrent
openings, and a larger exhalant opening (Fig. 192).

The Cnidaria3 have nettling organs of some sort.
Hydra belongs to this group.

There are two common species of Hydra ; the one is of
a green color {Hydra* viridis5)^ and the other is flesh-
colored {If. fuscaQ~). They are found in standing or slow-
running water, attached to submerged plants, sticks, and
stones. Throughout the winter they live at the bottom
of ponds, below the ice. The body of Hydra is soft and
highly contractile, so that, when first drawn from the
water, it appears like a speck of jelly. Left undisturbed,
the animal expands, and its five to eight tentacles wave

s, hollow; evrepov, intestine.
nettle.

3 A key to the principal subdivisions of the Cnidaria and especially
of the Hydromedusse will be found in the Appendix to this Chapter.

4 vdpa, a mythological monster, capable of regenerating its head.

5 Green. 6 Brown.

205

206

ZOOLOGY

slowly about in search of food. The tentacles are richly
supplied with nettling cells, each of which contains a
fluid-filled capsule, in which is coiled a thread-like tube.

FIG. 102. — Sycon gelatinosum. A portion slightly magnified: one cylinder
(that to the right) bisected longitudinally to show the central stomach
cavity opening on the exterior by the osculum, and the position of the incur-
rent and radial canals; the former indicated by the black bands, the latter
dotted, ip marks the position of three of the groups of inhalant pores at
the outer ends of the incurrent canals ; o, osculum.

When stimulated by contact with some foreign body the
tentacle closes around it, while from each capsule the
lasso-thread rolls out as the finger of a glove is rolled
inside out, and discharges the irritating poison .through

THE HYDRA AND ITS ALLIES

207

the lumen of the thread. If a small animal has been the
irritant, it is instantly caught in the thread, paralyzed by
the poison, and soon conveyed to the Hydra's mouth.
The principal food of Hydra is small worms and the
smaller Crustacea, such as Daphnia and Cyclops.

\ fWo/ ')

v) Ik

FIG. 193. — A colony of Cordylophora lacustris, on a shell of Mytilus. For
clearness, a number of the erect branches are cut off at the stolon, a, very
young shoot without lateral branches; b, young stock with lateral branches
but no gouophores; c, a stock with gonophores on lateral branches; d, fully
grown stock with lateral stems. After Schulze.

Fresh-water Cnidaria are of extremely few kinds.
Hydra was once regarded as the only instance, but
others are now known. One of these, called Cordylo-
phora, is found chiefly in brackish water or in fresh water,
near the coast. Like many of the marine hydroids, Cordy-

208 ZOOLOGY

lopliora produces its young in special capsules, called
gonophpres, which are rudimentary jelly-fishes (Fig. 193).
The young become free when they have gained an elon-
gated, cylindrical form. There are other fresh-water
species which have free jelly-fishes. In this country we
have a species, Microhydra l Ryderi, hitherto known only
about Philadelphia, whose hydroid stage is extremely
small and bears no tentacles. The jelly-fishes are set
free during July. Fresh-water jelly-fishes have also been
described from Lake Tanganyka, Africa, and from a tank
at Regent's Park, London, to which they had doubtless
been imported on plants. It is very probable that all
fresh-water hydroids which produce jelly-fish have, geo-
logically speaking, recently come from the sea. Hydra,
however, is probably a long-established fresh-water species.

The marine hydroids are, in contrast to the fresh- water
ones, very numerous. The Hydrocorallidae 2 are peculiar
in that they secrete a great amount of calcareous sub-
stance, so that they were formerly regarded as belonging
to the typical corals (Scyphozoa). They may be easily
distinguished by the absence of radial septae in the cups
occupied by the hydroid. Here belong the millepore
corals of Florida.

The Tubularidae3 include some hydroids of large size,
single individuals of Tubularia becoming six inches long.
Other species grow 011 gastropod shells which are occu-
pied by hermit-crabs (Figs. 194 and 195). So thickly do
they grow that they make a plush-like covering on the
upper part of the shell, and they have the curious habit

1 Small Hydra.

2 Combining the qualities of Hydra and the corals.

3 From tubulus, a little tube.

THE HYDRA AND TTN ALLIES

209

of building out the lip of the shell so as to enlarge the
aperture. They do this in order that the hermit-crab, as
it grows larger, shall not be
forced to exchange the shell
for a larger one, leaving the
hydroids on the cast-off shell
to roll about on the beach
and perish.

Of the Campanularidae,1 or
bell-hydroids, one of the
common representatives is
Obelia,2 which may be found
at low tide hanging from

-i i ,1 11 FIG. 1!H. — Stylactis, a tubularian

rocks beneath seaweed, and hydroid> gl.0^ugou asn:iiL Nat.

looking like delicate white size. Photo, of living animal by

threads (Fig. 196). Observed

FIG. 195. — Hydractinia, a tubularian hydroid. a, colony growing on gastro-
pod shell inhabited by a hermit-crab ; b, bit of colony enlarged ; dz, modified,
tactile, individuals; s, reproductive individuals; sp, spines. From Parker
and Haswell.

campanula, a little bell.

os, a spit.

210

ZOOLOGY

under the microscope each stem appears as a series of
hydranths placed in zigzag1 fashion, one beyond the other.

FIG. 10(!. — Obelia ( ?) , a group of campanularian hydroid colonies. Nat. size.

Photo, by W. H. C. P."

Another common kind is Sertularia,1 which forms rusty
brown threads (Fig. 197 ). All the hydranths of one stem

occur in one plane and
oppositely.

Both t u 1) 11 1 a r i a 11 and
c a m p a 11 u 1 a r i a 11 hy droids
may give rise to jelly-fishes.
These jelly-fishes are formed
as buds on the hydrant] i, and
after they become able to

move of themselves they are
;. 1<»7. — Sertularia, a small colony. J

i.r> nat, size. cut off from the parent and

1 Derived from serta, garland.

THE HYDRA AND J7'N ALLIES

211

swim away. The jelly-fishes then give rise to the sexual
products and discharge them into the water (Fig. 198).
In other cases the jelly-fish is formed but never separated

FIG. 198. — Bougainvillea ramosa. A, entire colony, natural size; B, portion
of the same magnified; C, immature medusa; dr. c, circular canal; cu,
cuticle or perisarc ; ent. ccw, enteric cavity ; hyd, polyp or hydranth; hyp,
hypostome or manubrium ; med, medusa; mnb, manubrium ; rad. c, radial
canal; t, tentacle; v, velum. From Parker's "Biology," after Allman.
This is closely allied to the New England B. super cllians.

212

ZOOLOGY

from the parent, and the eggs develop in the bud. In
still other cases a mere bud, called gonophore, is formed,
which becomes full of sexual products without ever ac-
quiring resemblance to a jelly-fish. The jelly-fish is the
primitive type which has undergone a reduction in some
cases to a gonophore. It is an interesting fact that in
certain species sometimes jelly-fishes and sometimes gono-
phores will be produced. In the Campanularidae the

FIG. 199. — Zygodactyla. Reduced. From a drawing by A. Ajjassiz.

gonophores are encased in a cuticular capsule, but in the
Tubularidse they are quite naked.

There are certain hydromedusre in which the hydroid
stage is unknown or known to be lacking. Here belong
some jelly-fishes of large size, like Zygodactyla, one of the
Trachomedusse of our coast, which may become eight to
ten inches in diameter (Fig. 199). Besides these the sea
contains many small species, which are easily captured in
the net, and which are of extreme beauty and delicacy.

Besides the Hydromedusre, the group of Hydrozoa in-
cludes the Siphonophora.1 These animals are always
colonial and free-swimming, and are among the most

1 0-/0WJ/, a siphon ; </>o/)6s, bearing.

THE HYDRA AND ITS ALLIES

213

beautiful inhabitants of the sea. Those who have crossed
the Atlantic are acquainted with the " Portuguese man-of-

•fon.

FIG. 200. — Physalia arethusa.
Nat. size. After Agassiz.

•net

nlc

FIG. 201. — Halistemma terge-
stinum. The entire colony.
cw, coenosarc; dz, dactylo-
zooid ; hph, hydrophyllium or

bract; net, nectocalyx or swimming-bell; ntc, battery of nematocysts;
p, polyp; pn, pneumatophore or float; t, tentacle. After Glaus.

214 ZOOLOGY

warv (Physalia,1 Fig. 192), which often swarms in the
Gulf Stream. The huge float which lies on the surface
of the water serves also as a sail by which the animal is
transported by the wind. There are other smaller, more
graceful species of more typical form (Fig. 201). The
structure of a siphonophore is very complex. From the
float hangs a central stem. Upon this stem are budded
feeding zooids — hydranth-like forms provided with mouth
and tentacles — and reproductive zooids- - gonophore-like
forms which produce the germ cells. There are leaf -like
expansions also, which are rudimentary medusae. All the
many forms budded on the stem are modifications of the
hydroid type.

Contrasted with the Hydrozoa are the Scyphozoa,2 which
are, on the whole, larger animals. These, too, occur both
in the sessile, polyp form and in the jelly-fish form. The
sea-anemones are common examples of the polyp. These
are, for the most part, solitary, fleshy creatures, often
brilliantly colored, and therefore appropriately called by
the Germans " sea-roses," and in this country and in Eng-
land " sea-anemones." They are of cylindrical form, bear
a circle of tentacles around the mouth at the upper end,
and have a muscular base by which they attach themselves.
They vary in diameter from one-sixth of an inch to two
feet. Some species live in the sand, out of which they get
some organic food, and at least one species (Minyass) is
free-swim m ing.

Our commonest Northern sea-anemone is Metridium
marginatum (Fig. 202), which occurs on rocky shores south

bladder. 2 o-Kixpos, cup ; fwoz>, animal.

3 For a figure of Mnyas, see Parker and Haswell, "Text-book of
Zoology," p. 189, Fig. 13U.

THE HYDRA AND ITS ALLIES

215

to New Jersey, but reaches its maximum development
along the coast of Maine. It varies greatly in color, some
individuals being white, others salmon-colored or olive.
The flat upper surface bears the slit-like opening to the
internal sac. Either one or both angles of this slit have
thickened edges, and corresponding to this difference is a

FIG. 202. — Metridium, one of our sea-anemones. Two individuals shown
expanded. Photo, of the living animals in the water, by W. H. C. P.

difference in the internal structure. Inside, the central
cavity is separated into compartments by radial partitions.
The coral polyp does not differ essentially from Metri-
clium. But it has the habit of secreting lime at its base,
so that, in course of time, a high cup is built up. The top
of the cup bears radial septa,1 which are laid down

i Fig. 203.

216

ZOOLOGY

in the interspaces between the fleshy partitions men-
tioned in speaking of Metridium. Since most corals, like

FIG. 203. — Coral cup of manicina. Nat. size. Photo, by W. H. C. P.

hvdroicls, bud freely, and since every bud secretes coral at
its base, an extensive and complicated limy mass may be
produced. This is the way in which the brain corals and

•6£tt***-.fi-i-^ •*.•>.
,- ,

FIG. 204. — Astranyla d<i)ite,a. cluster of our Northern coral-polyps, resting
on limy bases of their own secretion. The animals are extremely delicate
and transparent. From a lithograph by Louis Agassiz's artist Sonrel.

branching corals are formed. The only coral of the north-
eastern United States is Astrangia dance, which occurs
north to Cape Cod. It is a beautifully transparent species,
and forms thin encrustations of limy matter (Fig. 204).

THE HYDE A AND ITS ALLIES 217

Coral reefs are almost exclusively the product of coral
polyps modified by the environmental conditions. The
reef-building corals live in shallow water from low-water
mark to a depth of one hundred feet only. Their dis-
tribution along the coast line depends upon the winter
temperature of the sea, since they cannot live at a tem-
perature below 20° C. ; consequently reef -building corals
are confined to warm latitudes. However, tropical shores
which are washed by arctic currents, such as the west
coasts of Africa and South America, are destitute of coral
formations. On the other hand, shores in the temperate
zone that are washed by tropical currents, such as our
Florida coast which is washed by the Gulf Stream, may be
rich in coral reefs. Corals demand undiluted sea-water,
hence they do not thrive in harbors which receive the
waters of great rivers --a circumstance of great impor-
tance for the commerce of tropical countries. Moreover,
corals require a rock bottom on which to build, and they
cannot gain a foothold on shores where the cliffs descend
precipitously to great depths. Coral reefs receive dif-
ferent names according to their varying relations to the
shore. Fringing reefs are found close to the shore line.
Barrier reefs lie at some distance from land, with a body
of quiet water between them and the shore. An Atoll is
a further step, in which a small island, formerly sur-
rounded by a barrier reef, has disappeared, leaving a cir-
cular reef surrounding a body of water (Fig. 205).
Exactly how the central land disappears, whether by sub-
sidence of the sea floor as the reef grows up or by being
washed away, is still it matter of dispute.

Budding and the Formation of Colonies. The Cnidaria
are one of three groups of animals which have the habit of

218 ZOOLOGY

forming colonies by budding, somewhat after the fashion
of plants. The other groups are the Bryozoa, or " sea-
mats," and the Tunicata, or " sea-squirts." In all cases
the buds arise from a definite part of the parent body and
develop into a definite form, often exactly like that pro-
duced from the egg. When the buds remain attached to
the parent, a compound individual or colony is produced.
These colonies differ greatly in form. Thus among hy-
droids we have colonies which produce runners, from which
alone, and not from other hydranths, new hydranths arise.

FIG. 205. — Atoll iii Fiji Islands (Nanuku Levu). The large circle of white
made by breakers indicates the position of the coral reef. A small bit of
land still remains in the interior lagoon. Photo, by Dr. "W. McM. Wood-
worth. From A. Agassiz, " Coral Reefs of Fiji."

In another case (< )belia), one hydroid buds from the side
of another and rises beyond it, continuing the main stem
of the colony. Since its descendants do the same, the stalk
is made up of successive generations of hydranths. Some-
times the hydranths are placed close together and oppo-
site, like the leaves of Arbor vitte (Sertularia, Fig. 197).
Again, there may be a main stalk composed of one hy-
clranth and a series of lateral branches in one plane, mak-
ing a fan-like arrangement of the colony. Or the lateral

£5 *~

branches may arise in any plane, producing a bushy colony.

THE HYDRA AND ITS ALLIES

219

The variety in the form of the colony possessed even by a
single species adds to the diversity of hydroids.

The Ctenophora, or sea-walnuts, are a small group of
exclusively marine organisms which float on the surface
of the sea, and like most animals having this habit have
become clear as glass. Many of them are highly phos-
phorescent (Fig. 206).

In any colony a division of labor may occur among the
constituent individuals, or zooids. Thus in the simplest
cases we have crawling zooids,
or stolons, and feeding zooids.
In Hydractinia1 we have, in addi-
tion, reproductive zooids, nettling
zooids, and passive, thorn-like
zooids. Here we see how com-
pletely subservient the individual
is to the good of the community.
This subserviency has ruled in all
successful colonies of animals.

Regeneration. — Closely allied to
the power of budding is that of
reproducing a lost organ. Suppos-
ing the " head ' (mouth and ten-
tacles) of a Hydra to be cut off, the

base will reproduce the lost head. Suppose the base to be
removed, the head will reproduce a new base. When a
Hydra is cut in two transversely, two Hydras result where
formerly there was only one. Even three or more Hydras
may arise when a Hydra has been cut into so many pieces.
Where other conditions are favorable to life, you can
hardly kill a Hydra by mutilation. A trace of this

i Fig. 195.

FIG. 206. — Idylia, a sea-
walnut, seen from the
broad side. Half nat. size.
«, anal opening ; b, lateral
tube; c, circulai- tube ; d,<',
f, g, ft, rows of paddles.
After Agassi/.

220

ZOOLOGY

capacity for regeneration, as it is called, is seen also in
man when a wound heals, and a diseased organ, even when
partly destroyed, is made whole again.

APPENDIX TO CHAPTER XIV

KEY TO THE PRINCIPAL SUBDIVISIONS OF THE CNIDAKIA

a\. Body composed of 4, 6, or many rays ; nettling

organs well developed.
b\. Mouth at apex of an oval cone ; cavity

simple Class

c\. Existing for the most part in 2 forms ;
a sessile one, hydroid ; and a free-
swimming one, medusa. The hydroid
form is sessile ; the medusae are
mostly small, or may remain at-
tached to the hydroid . Order
c2. Free-swimming colonies composed of
hydroid and medusoid individuals
budded on a floating stem . Order

62- Mouth at bottom of an oral crater ; cavity di-
vided by radial partitions. The more com-
mon forms are large jelly-fishes . Class
«2. Body composed of 2 radii, with 8 meridional
rows of plates of cilia ; nettling capsules modi-
fied to form adhesive organs . . Class

Hydrozoa

Hydromedusce

Siphonophora

(Portuguese man-
of-war, etc.)

Scyphozoa

Ctenophora

(Sea-walnuts)

KEY TO THE FAMILIES OF THE HYDKOMEDUS.E

«i. Hydroid individuals, without cuticula or stolons ;
fresh water .

«2- Hydroid individuals, if present, with cuticula or
stolons; marine.

Hydroidw

(Ex. Hydra)

APPENDIX TO CHAPTER XIV 221

61. Hydroids present ; medusae without free

auditory clubs.

Ci. Hydroid stocks, with calcareous ex-
ternal skeleton ; no free medusae . Hydrocorallidce
Co. Hydroid heads never enclosed in cuticu-
lar cup ; medusae, if free, without
marginal vesicles ; gonads on manu-
brium ...... Tubularities

c3. Hydroid heads enclosed in calyx ; me-
dusae, if free, with gonads on radial

canals Campanularidce

b-2- Hydroids absent ; medusae with free-stand-
ing auditory clubs.

GI. Gonads on radial canals . . . Trachomedusas
Cz- Gonads on manubrium . . . Narcomedusas

CHAPTER XV

THE PARAMECIUM AND ITS ALLIES

PARAMECIUM l belongs to the Protozoa,2 the lowest
group of animals, characterized by the fact that the body
contains no specialized tissues and organs, but is made
up of a single cell, and is usually microscopic. Protozoa
live in water or in moist situations.3

The Infusoria were unknown to man until the latter
half of the seventeenth century, when a Dutch naturalist
named Leeuwenhoek, by means of the newly invented
compound microscope, studied and described several kinds
which he had found in standing water and called animal-
cuke or water insects. As the microscope became per-
fected, progress was made in the study of these organisms,
but even in the early half of our century several eminent
zoologists maintained that the Infusoria possessed digestive,
neural, hamial, and reproductive organs. The proper
structure of the Infusoria has been generally recognized
only within the last fifty years.

The conceptions formerly entertained concerning the
origin of Infusoria were as erroneous as those relating to
their internal structure. These erroneous conceptions
were an inheritance from a time when even scientific men

somewhat long.

2 -rrpwTos, earliest ; faov, animal.

3 Keys to the four classes of Protozoa and to the orders of Infusoria will
be found in the Appendix to this Chapter, page 229.

222

THE PAliAMECIUM AND ITS ALLIES 223

held that many of the larger animals, such as eels, bees,
and flies, were generated without parents. This was the
theory of "'spontaneous generation/' In time this theory
became much more restricted. It was found that the
maggots in putrid meat are not generated " spontaneously'
out of the meat, but are derived from flies' eggs, and, in
their turn, develop into fertile flies. But the idea that
Infusoria are formed out of inorganic material continued
to be held until much more recently, until Pasteur, Tyn-
dall, and others demonstrated that fluids heated to a
sufficiently high temperature for a sufficient time, and
then, while hot, sealed from contact with air, do not
develop Infusoria, no matter how long they may be kept.
This method of excluding Infusoria and other minute
organisms, especially bacteria, is employed to-day in can-
ning meat, vegetables, and fruit. The experiments re-
ferred to gave a death-blow to the theory of spontaneous
generation, and led to the conclusion that all Infusoria are
derived from living germs.

Whence the living germs come which enter the water
it is not difficult to determine. Many Infusoria can pass
into a quiescent "spore" stage in which they may be dried
and blown about without loss of life. Dry grass, straw,
and other substances contain some of the germs, and others
float in the air and fall as dust into the water. Even
drinking water may contain here and there an infusorian
or its germ. When, therefore, one fills a clean vessel
with pure water, and puts hay or dry leaves in it, and lets
it stand open to the air in a warm place, the result is
pretty sure to be that germs develop in the mixture.
The heat and the organic infusion merely facilitate this
development.

224

ZOOLOGY

Of all the Infusoria, none is more abundant than Para-
mecium. It occurs everywhere, principally in stagnant
fresh water, but also in salt water. It lives entirely on
vegetable food, and is sure to abound wherever plant
matter is undergoing decay. When a culture is once

FIG. 207. — Carchesium, a stalked Vorticella. Greatly magnified.

photograph of the living animals.

From a

started from a hay infusion, — which takes one or two
weeks, — it will be found to thrive especially on corn-meal.
As an example of the Heterotricha, Stentor,1 the trumpet-
animalcule, may be mentioned. Stentor is found attached
to vegetable debris — sticks, stones, water-weeds, and other
objects — occurring in pools, ponds, lakes, and sluggish
streams. These things should be gathered and placed in

1 ST<?I>TO>/>, a Greek at Troy, known for his loud voice.

THE PAEAMECIUM AND ITS ALLIES 225

an aquarium, when the Stentors, if present, will attach
themselves to the glass sides of the vessel. The attach-
ment of Stentor to objects is not permanent, for it may
loose its hold and swim free. When the animal is stained
in hcematoxylin, the characteristic nucleus, looking like a
chain of beads, becomes evident.

Vorticella,1 the bell-animalcule, is found in pools or
infusions, permanently attached by a long stalk. When
the animal is irritated, it contracts its stalk, which twists
into a close spiral. Carchesium 2 differs from Vorticella, in
forming colonies, so that a number of heads are attached
to a central stalk. A colony, when fully expanded, appears
like a fine, white mould attached to a submerged object.
In both of these types the food consists of small organic
particles, which are swept into the gullet by the circlet of
cilia placed around the upper end of the body.

The Suctoria3 are sessile Infusoria, from whose upper
surface numerous remarkable sucking-tentacles arise. By
means of these tentacles the animal can hold on to Para-
, mecia and other free-swimming Infusoria, from which it
extracts the body fluids. Some Suctoria are stalked (e.g.
Podopliora^, while others are unstalked (e.g. Aeineta'0).
They are found most abundantly in standing water, either
fresh or salt, and are often attached to other animals, -
Bryozoa, entomostracans, and pulmonate mollusks.

Of the group Flagellata,6 or lash-animalcules, Euglena7
is a common representative . It is of microscopic size, but
occurs in such numbers as often to give a decided green

1 Dim. from vortex, whirlpool. 4 TTOUS, foot ; 60/>tfs, eyebrow.

2 Kapxyviov, goblet, Fig. 207. 5 d/aVr/Tos, without movement.

3 From sugere, snctum, to suck. & JlayeUum, a lash.

7 evy\r)vos, with a beautiful eye.

226

ZOOLOGY

color to the pools of water it inhabits. It is spindle-
shaped, and bears a flagellum at its anterior end. At the
base of the flagellum is a red "eyespot."

Allied to Euglena is Volvox,1 a spherical, multicellular

c-.vac

FIG. 2<>S. — Eiif/lena viriilis, a lash-animalcule. A-D, four views illustrating
the characteristic movements ; E and //, enlarged views of adult ; F, out-
line of anterior end further enlarged ; G, resting stage ; cy, cyst ; .//, liagel-
huu ; m, mouth; nu, nucleus; w, gullet; pg, pigment spot; /•, reservoir.
After Kent and Klebs.

~~| organism, half animal and half
plant, and forming a sort of con-
necting link between the Pro-
tozoa (or one-celled animals) and
the multicellular higher organ-
isms. Volvox occurs abundantly
in our ponds and gets its name
from its manner of revolving in

FIG. 209. -- Volvox globator. t]ie water (Fig. 209).
Much magnified. Photo. Y, .'••.•••. £

of the living animal. Very different in habitat irom

1 From volvere, to roll.

THE PAEAMECIUM AND ITS ALLIES 227

the foregoing are the Sporozoa,1 which are minute rod-
like organisms, occurring as parasites in the body of
various kinds of higher animals, especially in the food-
tract. They increase by transverse division of their rod-
like bodies ; but periodically they encyst, and divide into
numerous "spores," which, under favorable conditions, are
set free in great numbers.

\ *': ;/?SiVr.Ar? ''

Jiiii; fv

(^?iii^m^m0^^n

~- ^-iSSfS?;0;|Sssk

FIG. 210. — Amoeba, the proteus animalcule. Greatly magnified, n, the
nucleus; w. v, water vacuoles ; c. ?-', contractile vacuoles; /. v, food vacuoles.
E. B. Wilson, "The Cell."

Of all Protozoa, probably the simplest is Amoeba.2 This
type varies greatly in size, from 0.02 mm. to about 0.3 mm.
It appears as a clear, highly refractive body of changing
outline. The body does not look homogeneous when
viewed with a high power, but contains various granules
derived from ingested food, vacuoles of water, and a trans-
parent, slightly more dense, spherical or ellipsoidal body,

1 0-7T6/OOS, spore ; fwoj/, animal.

2 aioi3? alteration.

228 ZOOLOGY

the nucleus, which it is often difficult to make out on the
living animal. The whole substance of the Amoeba is
mobile, so that the internal organs have no fixed relation
to one another. Quantities of Amoeba can usually be
obtained for study by gathering the mud from the edges
of stagnant pools, or by scraping the green growth from
flower-pots, and letting these gatherings, covered with a
little water, stand in a fairly warm place for two or three
weeks.

Even the Protozoa bear important relations to man.
One species, Amoeba coli, has long been known occasion-
ally to inhabit the food canal of man, and it is now known
that an amcebiform organism (probably one of the Sporo-
zoa) is the cause of malarial diseases. Since in one
common species 48 hours are required to complete a
developmental cycle, the recurrence of the fever every
alternate day is explained. It is now demonstrated that at
least one of the common agents in infection with malaria
is the mosquito, which carries the germs of the malaria
parasite from one host to another. Other Sporozoa, of at
least one species, are parasitic in the human liver, others
attack fish and cause them to die in large numbers; still
others cause sickness and death among domesticated
animals. The Texas fever among cattle is believed to be
caused by an organism l belonging to this group, the
inoculation of the cattle being effected by the cattle-tick.

The reproductive capacity of Protozoa is so great that
their importance in the world, despite their small size, is
not astonishing. One of the early students of Protozoa,
Ehrenberg, computed that from one individual of Para-
mecium aurelia 268,000,000 might be developed in one

1 Called Piroplasma biyauinum.

APPENDIX TO CHAPTER XV 229

month by the process of division. Apparently the divi-
sion cannot go on indefinitely, but from time to time the
Paramecia unite temporarily in pairs and undergo an
exchange of some of their nuclear matter. This is doubt-
less the beginning of what is known in the higher animals
as sexual reproduction.

APPENDIX TO CHAPTER XV

KEY TO THE FOUR CLASSES OF PROTOZOA

a\. Without non-retractile appendages.

bi. With retractile pseudopodia .... Rhizopoda

(Ex. Amoeba)

62. Without pseudopodia ; covered with an im-

perforate cuticula ; parasites . . . Sporozoa
«2. With non-retractile appendages.

61. No cilia, but with one or more flagella . . Flagellata

(Ex. Euglena)

62. With cilia, or sucking tentacles . . . Infusoria

(Ex. Paramecium)

KEY TO THE SUBCLASSES AND ORDERS OF INFUSORIA

a\. With vibratile cilia and no sucking tentacles . CILIATA

b\. Body everywhere closely beset with cilia.

GI. No adoral zone Holotricha

(Ex. Parameciuiu)

C2. Adoral zone present .... Heterotricha

(Ex. Stentor)

62. Body only partly ciliated.

GI. Cilia limited to ventral side . . . HypotriGha
c2. Cilia form a circlet around or at upper

edge of animal Peritricha

(Ex. Yorticella)

a2. With sucking tentacles . . ... SUCTORIA

CHAPTER XVI

THE SMELT AND ITS ALLIES

THE smelt is one of the class of fishes.1 This class com-
prises vertebrates that breathe by means of gills and do
not use their appendages for walking.

The smelts, which belong to the salmon family, are pre-
eminently inhabitants of the northern temperate zone,
since all but one of the ten genera occur only there. They
are small marine fishes, and although a feAv are inhabitants
of the deep sea, most live near the shore, and in the spring
ascend rivers to spawn. Some of them have become cut
off from descending to the sea and live permanently, as
tk land-locked " forms, in fresh water. Such " land-locked '
individuals are of smaller size than the marine ones. The
food of smelts, like that of other Salmonidee, is chiefly
animal, consisting of smaller fishes or insects, small crusta-
ceans, and mollusks.

Smelt are of considerable economic importance, since
they share with other members of the salmon family a
delicately flavored flesh. Our Atlantic form, Osmerus 2
mordaxf which ranges from Delaware Bay northward, is
caught most abundantly in Maine. The total Atlantic

1 Keys to the principal orders of fishes and the six suborders of the
Teleostei will be found at the end of this Chapter, page 252.

2 6o-/>o7p6s, odorous ; the Greek name is the equivalent of the English
"smelt." 3 Biting.

230

THE SMELT AND ITS ALLIES 231

smelt fishery is valued at 1125,000. Smelt eggs are arti-
ficially hatched and planted in rivers previously unin-
habited by them. Smelt are said to return to these rivers
after spending the winter in the sea. The early settlers
on our Eastern coast, like the Indians before them, used
smelt to fertilize the land. At present this wasteful pro-
ceeding is illegal ; but the bones and scraps from the
canning factories are used to make commercial fertilizers,
since they are rich in phosphorus — an important plant
food.

The family Salmonidae includes some of our most im-
portant food fishes. It is distinguished from other fami-
lies of Physostomi by the circumstances that both ventral
and adipose fins are present, that both premaxilla and
maxilla bear teeth l and form the margin of the upper jaw,
and that the head is naked, body scaly, belly rounded, and
pseudobranchue present. Besides the smelt there are
numerous important species. The salmon proper2 are
restricted to the north temperate and arctic regions, and
live either in the sea, migrating to fresh water to spawn,
or exclusively in brooks and lakes. The migrations of
salmon from the sea up the rivers are remarkable. Hun-
dreds of miles are sometimes journeyed, rapids swum, and
falls leaped, for the purpose of laying eggs in some remote
lake. The females, with their burden of eggs, have be-
come so exhausted at the end of the migration that most,
or all of them, die immediately after laying the eggs. On
the Atlantic coast the Penobscot River has the most im-
portant run of salmon. The Pacific salmon passes up the
Sacramento and Columbia rivers, and up many rivers of
British Columbia and Alaska. In these rivers the fish

211. 2Fig. 212.

232

ZOOLOGY

are caught as they ascend to breed. Such is the greedi-
ness and lack of foresight of the canning fisheries on the

Columbia River that very few salmon are permitted to
pass the nets of the canning factories, and consequently

THE SMELT ANT) ITS ALLIES

233

the apparently inexhaustible supply of this fish lias been
immensely reduced, and the fishery will soon become
destroyed.

FIG. 212. — Salmofario. ct. I, adipose lube of pelvic fin ; an, anus ; c./, caudal
fin ; d. /. 1, first dorsal ; d.f. ?, second dorsal or adipose fin : I. /, lateral line ;
op, operculum; pct.f, pectoral fin; pv.f, pelvic fin; v.f, ventral fin. After
Jardine.

The trout, of which there are a number of kinds on both
continents, is commercially much less important than the

FIG. 213. — Coregonus, the lake whitefish. Much reduced. From Goode.

salmon proper. As a result of overfishing, and the pollu-
tion of streams by factories and sewage, this fish is dis-
appearing from Eastern waters.

ZOOLOGY

The whitefish (Coregonus1), of which we possess many
species, is exclusively an inhabitant of fresh water.2 Its
teeth are almost completely absent, or very small ; it feeds
almost exclusively upon small arthropods and mollusks.
It is of very great commercial importance, its fisheries
being valued tit nearly three million dollars a year.

Leaving now the Salmonidse, we may briefly consider
some of the other more important families of bony fishes.

FK;. 21-4. — Morone americana, the white perch. The fish is searching for food
along the bottom of the aquarium, an instinct which it shows in nature also.
About one-third nat. size. Photo, of living animal by Dr. R. W. Shufeldt,
from " Bull. U. S. Fish Com.," 1899.

The darters are spiny-rayed fishes of small size, from four
to seventeen centimetres long, brightly colored, and with
well-developed pectoral fins. They live in clear streams,
half concealed under stones, and are most abundant in the
Mississippi drainage basin.

, the pupil of the eye ; ywvia, angle.

2Fig. 213.

THE SMELT AND ITS ALLIES

235

The perches are a widespread family, represented in this
country chiefly by the common yellow perch of the East,
the u wall-eyed pike ' ' of the Great Lake region, and the
white perch of the Atlantic coast (Fig. 214). These fish
have an oblong, compressed body covered with small
scales ; they are highly rapacious, and are believed to be

FIG. 215. — Eupomatis yibbosus, the common sunfish. Two-thirds uat. size.
Photo, of living animal by Dr. R. W. Slmfeldt, "Bull. U. 8. Fish Com.,"

1899.

destructive to the young of other species of fish. They
are esteemed as food, although fortunately not to the
extent of annihilation.

The sunfishes1 have a percoid form, but have only one
dorsal rln instead of two. They live in fresh water, have

1 Fio-. 215.

236

ZOOLOGY

rapacious habits, are brilliantly colored, and build nests in
the sand, which both male and female watch over and

defend with courage. Some species
living in the Great Lakes are known
as black bass or rock bass. The
small New England species, with the
brilliant red edge to the operculum,
is called pumpkin-seed.

The toadfishes (Fig. 216) are
represented in our faunas by a
common species which lives under
stones in harbors and attaches its
eggs to the under side of stones. It
is a vigorous fighter.

The sculpin (Fig. 217) is closely
related to the toadfish. Like the
latter it has a broad head and nearly
scaleless body. The pectorals are
large, and the two dorsals extend
along the greater part of the back.
Allied to the foregoing is the rock eel (Fig. 218), which
is sometimes brought up in the seine from a depth of 8 to
10 fathoms.

FIG. 216. — Batrachus tau,
the toadfish. Dorsal
view. Two-thirds nat.
size. Photo, by W. H.
C. P.

FIG. 217. — Acanthocottns, the little sculpin. Two-thirds nat. size. Photo.

by AV. H. C. P.

The silversides are especially abundant along our At-
lantic coast. They have an elongated, somewhat com-

THE SMELT AND ITS ALLIES

237

pressed body, and a broad, bright silvery band on the
sides, against a greenish general body color. The dorsal

x. : •"

FIG. 218. — Pholis, the rock eel. Right side. Nat. size. Photo, hy W. H. C. P.

spines are slender. The fish swim near shore, in dense
schools. One species on the Californian coast is known as
a "smelt," and is a good food fish.

FIG. 219. — Gasterosteus punyitius, the nine-spined stickleback; male (above)
and female near the nest in rushes. The female is about to deposit its eggs
in the nest.

238

ZOOLOGY

The sticklebacks are small, elongated fishes, having an
extremely slender tail and a large mouth. The dorsal fin
is preceded by two or more large isolated spines. The
fishes live in either fresh or brackish water. In some of

FIG. 220. — Gasterostea.s bispinvaux, the two-spined stickleback. Above, nest
with eggs, and male entering. Below, male depositing its mil on the eggs.

Figs. 219 and 220 are reproductions of water-color paintings in the Museum
of Comparative Zoology at Harvard College.

the species the male builds an elaborate nest from bits of
aquatic plants, firmly united by a special mucilaginous
secretion. The nest, which is built among the plants of
the stream, consists of a short cylinder, through the hori-

THE SMELT AND ITS ALLIES

239

zontal cavity of which the fish can lie while it deposits its
eggs. The male is polygamous, and guards the single
nest, which receives the eggs from various females (Figs.
219, 220).

The codfishes, among the most important of food fishes,
are characterized by having ventral fins without spines,
and articulated fin-rays, well-developed caudal fin, isocercal
tail, and barbel on chin. Our common codfish (Fig. 221)

. 221. — Gad its morrhua, the codfish. About one-seventh nat. size.

After Storer.

occurs over the whole of the North Atlantic ; but the
most important fishing localities are the banks near New-
foundland, especially Grand Bank.

The flatfishes are peculiar among fishes in that they
have the habit in the adult stage of lying on one side. In
consequence the under eye migrates to the upper side, so
that both eyes come to lie on the same side of the body.
The mouth also tends to become unsymmetrical. The
flatfish, consequently, illustrates well the principles of self-
adaptation to a peculiar environment.

The catfishes are distinguished by the possession of
four to eight long barbels around the mouth, and by the

240

ZOOLOGY

absence of scales on the body. They are characteristic of
South America, but there are a large number of species in
the United States, mostly found in the Mississippi valley

• ->>.•. X '

* .§ . * '

;« -*

X x\
X X VV

, v\V

FIG. 222. — One of the flatfishes, seen from the upper side. Two-thirds nat.

sixe. Photo, by W. H. C. P.

and the Great Lakes, inhabiting deep or sluggish waters,
and living in the mud. The common New England

FIG. 22-"». — Anicairus iirhtilosiix, the catfish. About one-half nat. size. Photo,
of living animal by Dr. R. AV. Shufehlt, " Bull. U. S. Fish Com.," 1899.

THE KNELT ANT) ITS ALLIES

241

pecies is Ameiurus1 catus? the bull-head or horn-pout.3
t was with reference to this species that Thoreau wrote
hat they are "a bloodthirsty and bullying race of rangers,
ahabiting the river-bottoms, with ever a lance at rest and
eady to do battle with their nearest neighbor." The
tiff, jagged rays of the pectoral fins can make severe
vounds. The great catfish of the Mississippi River,
vhich may weigh up to 90 kilogrammes, is known as
imeiurus lacustris.^ This, as well as most other species
•f catfish, is much prized as food.

FIG. 224. —The brook sucker. After Goode.

The suckers are characteristic North American fish,
ibundant in every creek, and consequently known to every
over of woods and brooks. Characteristic is the form of
ips, which are thick and drawn down at the corners.5 They
ire rather sluggish fishes, and feed on small aquatic insects
tnd suck up mud. They are not generally esteemed as
ood, inasmuch as their flesh is coarse and very full of
)ones. In the Mississippi valley, however, they are so
ibundant and large that they are of some commercial
mportance.

not curtailed. 2 Cat. 3 Fig. 223.

Living in lakes.

5 Fig. 224.

242 ZOOLOGY

The term "minnow" is applied to two distinct families of
small fish. One of these is also known as " killifish." The
killifish have a broad head covered with scales, and have
well-developed teeth in the month. They occur in schools
in shallow water on the shore, and ascend streams to their
sonrce. They are carnivorous, and feed at the surface.
In one species from the Southern coast, Heterandria l for-
mosa,2 the male is only about two centimetres long, and is
the smallest known vertebrate. Our commonest species on

FIG. 225. — Fumhdus heteroclitus, a killifish or shore minnow. Xat. size.

Photo, by W. H. C. P.

the shore, or in brackish water, is Fiindiilm 3 heteroclitus 4
(Fig. 225). The minnows of the other family have a nar-
row head without scales, and with no teeth in the mouth.
They occur exclusively in fresh water, and are known as
"shiners." The " goldfish" is related to this group.

The pike and pickerel (Esox5) are roughly cylindrical
fishes, with large mouth, elongated, depressed jaws, and
strong, hooked teeth.6 They are large, voracious, fresh-
water fishes, confined, with the exception of a single species,
to the United States. The " muskallunge " of the Great

s, different ; <ii>r)p, avdpos, man, male. 2 Comely.

3 fundus, bottom. 4 erepo/cXtros, irregular or unusual.

5 f<ro£, a fish living in the Rhine, mentioned by Pliny.

6 Fig. 220.

THE SMELT ANT) ITS ALLIES

243

Lakes reaches a length of two metres. It is, fortunately,
somewhat rare, otherwise there would be few other in-

habitants of our large streams.

FIG. 226. — Lucius luchts, the pike. About one-fifth nat. size. Photo, of
living animal by Dr. K. W. Shufeldt, " Bull. U. S. Fish Com.," 1899.

The shad is a representative of a family — the herring
family — which has played an important part in the civiliza-
tion of Europe. There is an old adage in Holland to the

FIG. 227. — Alosa sapidissima, the shad. After Goode.

effect that Amsterdam is built on herring-bones ; and the
Emperor Charles V. said that the herring brought greater
wealth to the Netherlands than did America to Spain.
Our common shad, Alosa1 sapidissima,2 ranges from New-

1 From Saxon all is, old name of the European shad.

2 Most delicious.

244 ZOOLOGY

foundland to Florida.1 Next to the Pacific salmon and
cod, it is commercially our most important fish, for the
catch of Atlantic shad for 1896 exceeded one and a half
million dollars. The Pacific coast has been successfully
stocked with shad from the Atlantic. The Atlantic shad,
like the salmon, migrate up streams to deposit their eggs.
The alewives have the same habit. The herring, on the
contrary, spawn in the sea. As the common name, allied
to the German Heer, an army, implies, they travel in great
schools. The menhaden, which also occur in great schools,
have of late years been destroyed in vast numbers to make
fertilizers.

The eels are easily distinguished by their serpentine
form, the absence of ventral fins, the long dorsal fin, and
the rudimentary or absent scales. These fish occur all
along our coast and ascend streams. During the day they
lie hidden in mud and at night they feed, their principal
prey being small aquatic animals, the young of other fish,
and shrimps and crayfishes during the moulting period.
On account of the narrowness of the gill-opening, they
may live for some time out of water in a moist place. The
reproduction of the eel was long a mystery. All sorts of
creatures have in past times been supposed to produce
them, ranging from the gods to water-beetles. They have
even been thought to be generated from slime. We now
know, however, that there are both male and female indi-
viduals ; that the males live chiefly, but not exclusively, in
the sea ; that reproduction occurs chiefly in the sea ; and
that the young females come from the sea and pass up the
rivers during the spring.

The pipe-fishes and their allies (Lophobranchii) include

Fig. 227.

THE KNELT AND ITS ALLIES

245

a number of aberrant forms. Some of these are greatly
elongated, like the pipe-fish proper (Fig. 228) ; others are
shorter and stouter, like the u sea-horse." All have an

FIG. 228. — Siphostomafuscum, the pipe-fish. Nat. size. Photo, by W. H. C. P.

elongated snout, and usually a long, slender tail. The
body is encased in bony plates, and the male is often pro-
vided with a brood-pouch, in which the developing young
are carried.

Besides the bony fishes, which we have just considered
in detail, there are various other classes of fish.

FIG. 22l>. — Petromyzon, the lamprey. One-fourth nat. size. After Goode.

The Cyclostomi, or lamprey eels, are the only parasitic
vertebrates. In the adult stage they either live attached

246

ZOOLOGY

to the outside of other fishes, sucking their blood, or else

they may penetrate into
the body cavity. They
do not bite, because they
have no lower jaw, and
are known as "round-
mouthed' eels.1 Lam-
preys are found in the seas
and in the rivers of the
temperate zones. They
occur on our Eastern
coast and ascend rivers ;
others live in the lakes of
New York, in the Great
Lakes, and in the Missis-
sippi valley. In Europe
they are much esteemed
as food.

The Selachians include
the sharks and rays, all
inhabitants of the sea.
They may be distin-
guished from the bony
fishes by the rough skin,
beset with spines, and by
the cartilaginous skele-
ton. We have a num-
ber of sharks on our
Northeastern coast, of
which the dogfishes and
the sand-shark are the

i Fig. 229.

THE SMELT ANU ITS ALLIED

247

commonest (Fig. 230). They are all carnivorous animals
and powerful swimmers. They feed on the larger Crus-
tacea and fish.

The living Ganoidei are a remnant of a very extensive
group which existed in geological times. North America
is especially rich in existing representatives of this group,
as of several other old groups, such as the turtles, tailed
amphibians, and the king-crab. Of the five families of
ganoids, four are represented in this country. In the
following four paragraphs we shall consider a type of each
of the native families.

The sturgeons have five rows of bony scales on the
trunk and four barbels on the head.1 They occur both

FIG. 231. — Acipenser, the sturgeon. One-sixteenth nat. size. After Goode.

in the sea and in the Great Lakes and the rivers of the
Central States. Although of large size, they feed for the
most part on small aquatic animals, such as worms, insect
larvse, and small fish. The flesh of some species is much
used as food ; the eggs taken from the ovaries (roe) con-
stitute a delicacy known as "caviare."

The spoonbill, which has an elongated, flattened snout
and is almost without scales, is a large fish found in
the Mississippi River. It is also called u paddle-fish " or
" duck-bill catfish." It becomes two metres long and seeks
small animals in the mud, which it stirs up with its snout.

i Fig. 231.

248

ZOOLOGY

The garpikes are known by their long snout (Fig 232).
They are completely clad in an enamel coat of mail. They
are of sluggish habits, but voracious, and their flesh is

FIG. 232. — Lepidosteus, the garpike. One-eighth nat. size. After Teimey.

valueless as food. One species is found in China, the
others in the rivers of North America.

The bowfin (Amia1) occurs in the rivers and lakes of
the United States. It has a short body, a blunt head, and

FIG. 233. — Amia calva, the howtiii. One-sixth nat. size. From Leuuis.

a long, dorsal fin (Fig. 233). It is the sole survivor of a
formerly large family.

The Dipnoi 2 include only three rare foreign forms, which
seem to form a transition between fishes and the higher
groups, for some of them have lungs in addition to gills.
From some such lunged fishes must the amphibia have
arisen (Fig. 234).

Ancestry of Vertebrates. - The fishes, amphibia, reptiles,
birds, and mammals, which are considered in this and the
following chapters, constitute together the group of verte-
brata, or backboned animals. All the animals treated of

1 dut'a, ancient name of a fish.

2 si

Si's, twice ; irvo-fj, breath.

TUE SMELT AND ITS ALLIES

249

Nit II

r- ...

- 3

—

250

ZOOLOGY

FIG. 236. -- Ciona, a simple
tunicate, o, mouth ; at, open-
ing of atrium, or exhalant
opening; st, stolon. After
Leuckart aud Nitclie's dia-
grams.

FIG. 238. - - Balanoglossus, the acorn-
tongued worm. The proboscis at the
anterior end is at the top of the figure
(partly outside) ; behind it is an
orange-colored collar: then follows
the long, brown-red trunk. Nat. size.
Photo, of living animal by W. H. C. P.

FIG. 237. — Botryllus, a compound tunicate. Nat. size. Photo, by W. H. C. P.

THE SMELT AND ITS ALLIES 251

in earlier chapters are invertebrates. Between verte-
brates and invertebrates and connecting the fishes with
more worm-like ancestors, is the lancelet or Amphioxus.1
This slender, rod-like animal is only 50 to 70 milli-
metres long. Its internal structure shows its relationship
with vertebrates ; it has the forerunner of a vertebral
column and a spiral nerve and it has also gill slits like a
fish, but it has no skeleton.2 It lives in sandy seashores
in temperate and tropical zones. On our Eastern coast it
is found from Chesapeake Bay south. It stands embedded
in the sand, the tentacle-fringed mouth projecting above
the surface. It feeds on minute organisms of all sorts.

Of the invertebrate groups, that of Tunicata lies nearest
to the stem from which the vertebrates arose. The adult
animals, however, are very different from vertebrates, for
they are attached (Fig. 236), and sometimes even form
colonies (Fig. 237). But the young animals are much
like tadpoles of frogs ; not merely superficially, but in
their structure. Going further back it seems clear that
vertebrates have developed out of the worms. A very
worm-like animal, which seems to foreshadow the verte-
brates in having gill slits and the forerunner of a back-
bone, is common in our sandy beaches. This is Balano-
glossus3 — the acorn-tongued worm, so called from the
shape of its proboscis (Fig. 238).

i', both [endsj ; 6£tfs, sharp pointed.
2 Fig. 235. 3 /SdAaws, acorn ; 7\£(rcra, tongue.

252

ZOOLOGY

APPENDIX TO CHAPTER XVI

KEY TO THE PRINCIPAL ORDERS OF FISHES

«i. Without skull, paired fins, or heart ; blood color-

ACoo •••*•• •••

a*. With skull, heart, and red blood [Craniota].
61. Without lower jaw or paired fins

b-2- With lower jaw and paired fins [Gnatho-

stomij.
Ci. Intestine with spiral valve.

d\. Without an operculum covering
the gill openings ; scales toothed

dz- Operculate ; skin with enamelled

scales.

e\. Breathing by means of gills
only . . .

e2. Breathing by both gills and
a lung ....

c2. Intestine without spiral valve ; skele-
ton bony

Acrania

(Ex. Amphioxus)

Cyclostomi

(Lamprey eels)

Selachii

(Sharks and rays)

Ganoidei
(Ganoid fishes)

Dipnoi

(Mud fishes)

Teleostei

(Bony Fishes)

KEY TO THE SIX SUBORDERS OF TELEOSTEI
«i. Gills comb-like.

J»i. Intermaxillaries and maxillaries movable

on each other.
Ci. Dorsal fin, anal fin, and ventral fin

spinons anteriorly.
d\. Pharyngeal bones distinct . . Acanthopteri

(Perches, darters, sunfishes, toadfishes, sculpins, silversides,

sticklebacks)

d-2. Pharyngeal bones united . . Pharyngognathi
c2. Dorsal, anal, and ventral fins without
spines.

APPENDIX TO CHAPTER XVI

253

fl-2-

d\. Ventral fin, when present, placed
on throat or breast ; air-bladder
without air tube . . . Anacanthini

(Codfishes, flatfishes)

do. Ventral fin, when present, placed
ventrally ; air-bladder with air-
tube Physostomi

(Smelt, trouts, whitefishes, catfishes, suckers, minnows,

shads, eels)

&2. Intermaxillaries and maxillaries united with

each other and with skull . . . Plectognathi
Gills small, tuft-like ; body covered with bony
plates Lophobranchii

(Pipe-fishes)

CHAPTER XVII

THE NEWT AND ITS ALLIES

THE newts belong to the class Amphibia,1 or, as it is
also called, Batrachia, characterized by the fact that, while
they have no rayed fins like fishes, but legs instead, they
have functional gills during at least a part of their free
life. The eggs, which are laid in water, are without a
hard shell.

The little newt Diemyctylus viridescens 2 is found in
New England and westward to the Mississippi valley.
During different stages of development it assumes widely
different habits. The eggs are laid during the spring in
water, where they hatch after three to five weeks and
appear as olive-colored tadpoles with external gills. At
this time they have an exclusively animal diet, feeding on
minute Crustacea, larval insects, snails, and aquatic worms.
In August the gills and tail-fin become absorbed, and the
transformed animal takes to land and lives under stones
at some distance, it may be, from water. At this time it
has a vermilion color,3 and feeds on spiders, insects, and
earthworms. After two or three years the newt assumes a

1 Keys to the Orders of Amphibia and to the families of Urodela will
be found in the Appendix to this Chapter, page 266.

2 The newt of the Pacific coast is D. torosus.

3 The color and habitat of the terrestrial young Diemyctylus are so
different from the fully matured aquatic form that the two were formerly
regarded as distinct species.

254

THE NEWT AND TTS ALLIES 255

brown color, and eventually the olive-green or viridescent
color of the adult. It then takes to the water and is
found especially in springs, and in ponds and brooks fed
by springs. It now subsists on various aquatic worms,
crustaceans, insects, and mollusks. The newt gains oxygen
for respiration by swallowing air mixed with water.1

Distribution.- -The Amphibia live chiefly in tropical and
subtropical countries, although a number of them belong
to the colder parts of the temperate zone. There are no
strictly polar species, although one species of frog extends
from Massachusetts north to Alaska. The Gymnophiona 2
are confined to tropical countries and are most abundant
in South America. They live, like earthworms, in the
ground and have more or less rudimentary eyes. The
Urodela are confined in their distribution to the Northern
Hemisphere (excepting that two or three species extend
along the Andes south of the equator). North America
is especially rich, both in species and individuals, of Uro-
dela. The Anura, or toads and frogs, are found in all parts
of the world, especially in South America and Australia.

Families of Urodela. — Of the American Urodela,3 the
Sirenidae include the Siren,4 or mud-eel, of the Southern
States. This species becomes 60 centimetres long, and is
of a dark lead color (Fig. 239). It is needlessly feared
by the negro rice cultivators, who slaughter it in great
numbers.

1 Newts may be captured by sweeping with a net the muddy bottoms
of small, spring-fed pools. They can be kept for months in an aquarium,
where they should be fed thrice a week with earthworms or freshly
chopped beef.

2 From yv/j.v6s, naked ; 60iW, a fabulous, snake-like animal.

3 ovpd, tail ; 577X05, conspicuous. * A mythological creature.

256

ZOOLOGY

S-i

•— J
rr- +->

a .22

01 2
0 c3

J^ 3

C--J

THE NEWT ANT) ITS ALLIES 2">7

The Proteidae 1 include our Necturus, commonly known
as mud-puppy or water-dog, which is found from the
Hudson River to the Mississippi valley, and is very
abundant in the Great Lakes. Its external gills are
very large, and red with the blood flowing in them. It
feeds on small water-animals. In April or May it lays
eggs about the size of a pea. A curiously modified form
of Necturus occurs in caves (Fig. 240). Another member
of this family is the cave u olm "' of western Austria.

The Amphiumidae 2 include only the Congo snake of
the Carolinas and Gulf States. This black, snake-like
Urodelian is about a metre long, and lives in bayous and
muddy dit dies (Fig. 241). It has the entirely undeserved
reputation of being injurious.

The Cryptobranchidae 3 include the so-called "hell-
bender' of the Ohio valley and south.4 It is a very
voracious scavenger of the water, and bites the hook
fiercely. It is noted for its great tenacity of life under
unfavorable conditions. The only other living repre-
sentative of this family is the Japanese giant salamander,
which becomes three metres long.

The Amblystomidae 5 include some twenty-five species
belonging to five genera, four of which occur in northern

O O o

and eastern Asia, and the fifth, Amblystoma, is confined
to the United States and Mexico, excepting one species,
occurring in Siam. The common species of New England
and the Central States is known as the Spotted Sala-

1 Hporeys, a sea-god possessed of the power of changing himself into
different shapes.

'2 Probably a modification of a native name.

3 /cpi'Trros, hidden ; /3/>d7xio;>, S1^-

4 Fig. 242. 5 From d/i/SMs, blunt ; crT6/j.a, mouth.

258

ZOOLOGY

mander. It is about 15 centimetres long, and black, with
a series of yellow spots on each side of the back. It lays

•'" •"•1111,-v^

^— *MniK»

^*_;v

FIG. 242. — Cryptobranchus, the " hellbender." Reduced. From " .Stand-
ard Natural History."

eggs in springs or ponds during April ; the dark gray
eggs are contained in great masses of jelly which are

FIG. 24o. --The larva of Ambli/stowa tif/riiium, the Axolotl stage of the tiger

salamander. From Mivart.

THE NEWT AND ITS ALLIES

259

attached to sticks at or near the surface of the water.
The larvae of the more southern species often reach a size
considerably larger than the adult, and breed before the
gills are absorbed. In a Mexican species the larval
state is never transcended. The larva of Amblystoma
(Fig. 243) was formerly described, indeed, as a distinct
species.

The Plethodontidae a and Desmognathidae 2 include a num-
ber of small Urodeles, having a close general resemblance

Fi<;. 244. — Plethodon, the red-backed salamander. Slightly reduced. Photo.

of living animal resting on a leaf.

and similar habits. Plethodon, of the eastern United
States, is lead-colored above, very often with a broad,
red dorsal band (Fig. 244). It is found under logs,
and is very active. Spelerpes3 is lemon-yellow and white
below, and Desmognathus is brown above, with gray or

s, abundance ; odo^s, 656fTos, tooth. 2 5e<r/x6s, bond ;

jaw. 3 (TTTTjAcuoj/, cavern ; epir-rjs, a crawler.

260 ZOOLOGY

purplish spots on the sides. Both Spelerpes and Desmo-
gnathus live in and about running brooks, under stones
and fallen logs. Their eggs are attached to the under
surface of submerged stones. The adults are easy to keep
in confinement in a moist fernery. They may be obtained
out of doors all the year round, excepting during the time of
deep snow. There are four species of Spelerpes and three
species of Desmognathus in the northern United States.

Metamorphosis. — As we have seen, all Amphibia have
gills while young, but some lose them before maturity
while others retain them permanently. Those species
which retain the gills pass their whole life in water ; the
others may live on the land. The loss of gills is asso-
ciated with the assumption of a land life. In the Ambly-
stoma we have species which are curiously intermediate
between the two classes in that they may retain their
gills, tail-fins, and other structures adapted to aquatic life,1
even to the time of reproduction ; or they ma}T lose their
gills and tail-fins. The first result follows if they are pre-
vented from coming on land ; the second, if they are forced
to leave the water. The capacity of the Mexican Axolotl
for either becomino- an adult or remaining1 a larva was

o o

first shown by some experiments of the German naturalist
Weismann and a pupil of his. It Avill be seen that when
forced to live in the water Axolotl retains permanently
a larval condition ; and one would never know that in this
larval condition the animal is not adult were it not for the
accident of its sometimes becoming adult. It is quite
possible that all of the Urodela which retain their gills
throughout life may formerly have had a gill-less adult
stage which is now lost.

1 Compare Fig. 243.

THE NEWT A XI) ITS ALLIES

Early Development of Urodela. — The eggs of Urodela
are deposited in a gelatinous mass in water, and are
attached to submerged plants, or to other objects in the

FIG. 5.

FIG. 7.

I IG. 10.

FIG. 12.

FIG. 6.

FIG. 8.

FIG. ii.

FIG. 13.

FIG. 14.

FIG. 9.

FIG. 17.

FIG. 15.

FIG. 1 8.

FIG. 16.

FIG. 19.

FIG. 245. — Developmental stages of Spelerpcsbilineatus. Fif/x. '>-!>, neural
groove beginning to form; Figs. 10, 11, iieural groove closed; Flys. 7?, 7.7,
liead beginning to form; Fiyx. 14-ln, tail formed, yolk absorbing; Fiy. 17,
embryo capable of moving in egg membrane : Fiy. 18, embryo just able to
swim ; Fiy. lit, three days after hatching. The letters indicate the successive
stages. After H. H. Wilder, from ''The American Naturalist."

water, either singly or in masses, according to the species.
The eggs contain much yolk ; consequently the cleavage is
partial, and the embryo seems to develop on a small part

262

ZOOLOGY

only of the yolk and for some time after hatching the yolk
mass hangs as a lump on the under side of the embryo.
Very early a deep groove, bounded by a pair of folds,
arises on the edge. This groove is large in front (Fig.
245, />). It forms the beginning of the brain and spinal cord.
The feathery gills and the beginnings of the appendages

SS^L

Fi<i. 246. — Pipa americana. Female with young in pits on its back.

next sprout out, while the trunk continues to elongate and
assume the form of a young salamander (Fig. 245).

Families of Anura. - - Of the Anura there are eight or
ten times as many species as there are of the Urodela.
They are distributed into nearly a score of families. Of

THE XEWT AND ITS ALLIES

263

these a few of the more interesting deserve to be men-
tioned.

FIG. 247. — Section through skin of back of Pipa amarircuia, showing develop-
ing embryos. Much enlarged.

The Pipidae include the South American Pipa, note-
worthy because of the habit which the female has of
brooding its young in pits of the skin on her back
(Figs. 24ti, 247).

FIG. 248. — Nodelphys, brooding tree-frog, female, from Venezuela. In the
hinder part of the trunk the opening to the brood-pouch is seen. From a water-
color painting at the Museum of Comparative Zoology at Harvard College.

The Hylidae, or tree-toads, include various arboreal
species in which the ends of the fingers are modified for

264

ZOOLOGY

holding on to objects by suction. Of these there are over
one hundred and seventy species, especially abundant
in tropical America. In one member of this family the
female has a pouch on the back, opening in the hinder
third of the trunk (Fig. 248). In this the young arc

FKJ. 2-49. — J>t(fo lentlginosus, the American toad. Photo, of living animal,

resting on the ground, by W. H. C. P.

brooded. The most common tree-toad of the northern
United States extends from Canada to Florida, and west
to Kansas. It is variable in color, being green or brown,
according to the color of the background, leaf, or bark,
on which it is resting. It has a loud, coarse trill, often

THE NEWT AND ITS ALLIED

erroneously regarded as a weather sign. The eggs are

\j t~} CJ CJ <J

laid in small bunches in shallow water.

The Bufonidae include the common toads which occur
all over the world. Our Eastern toad1 inhabits nearly all
the United States east of the Rocky Mountains.2 It is
crepuscular in its habits, and feeds chiefly on insects and
worms. The eggs are deposited in two long, parallel
strings of albumen, which lie coiled at the bottoms of

FIG. 250. — Runa clanutano, green frog. Nat. size. Photo, of living animal

by W. H. C. P.

ponds, hatch out in May, and metamorphose about a
month later.

The Ranidae are almost confined to the Northern Hemi-
sphere and the East Indies. In the northern United States
there are some eight species, of which the commonest are:
the leopard-frog, of green color, with irregular black
blotches edged with whitish ; the pickerel-frog, light
brown, with two rows of oblong square brown blotches

JBufo Icntiyinosus.

- Fig. 249.

266 ZOOLOGY

on the back ; the wood-frog, living in damp woods, pale
reddish brown, with a brown band on the side of the head ;
the green frog, of uniform bright green to brown color,
with numerous small dark spots, and with glandular folds
(Fig. 250) ; and the bull-frog, of great size, green, with
small faint spots on the back.

APPENDIX TO CHAPTER XVII

KEY TO THE ORDERS OF AMPHIBIA

«i. Appendages and tail lacking; body worm-like ;

skin furrowed transversely .... GymnopMona

a2. Appendages present.

61. Body elongated ; tail present ; generally 4,
but rarely only the 2 anterior appendages
present . ..... Urodela

&2- Body short ; in adult condition tailless . Anura

KEY TO THE FAMILIES OF URODELA

a\. External gills persistent throughout life ; maxil-
lary bone small or wanting.
61. Body eel-like ; hind legs absent ; jaws with

horny sheath ...... Siroii'lir

1>>2. Body salamander-like ; hind limbs present ;

teeth on jaws Proteidcu

«2- External gills normally disappearing in adult ;

limbs 4 ; maxillaries present.
&i. Side of neck with spiracular opening ; no

eyelids.

ex. Limbs rudimentary .... Amphiwnidai
c-2. Limbs well developed .... Cryptobranchidce
b->. Side of neck without spiracular opening in
adult ; eyelids present.

APPENDIX TO CHAPTER XVII

267

Ci. Palatine teeth in transverse (or nearly

transverse) series.
d\. Vertebrse doubly concave.

e\. Parasphenoid without teeth ;

tongue large ; toes 4-5
e-2. Parasphenoid with teeth ;

tongue small
d*. Vertebras convex behind only ;

tongue moderate ; toes 5
C2. Palatine teeth in 2 longitudinal series,
diverging behind ....

AmblystomidcB

Plethodontidce

Desmognathidce

Pleurodelidcp.
(Ex. Diemyctylus)

CHAPTER XVIII

THE LIZARD AND ITS ALLIES

THE lizards belong to the class of Reptiles,1 which are
vertebrates in whose skin horny or bony scales or plates
are formed. They constantly breathe by means of lungs,
and lay large eggs provided with a tough leathery or
calcareous shell.

The Sauria, or lizards, constitute a large order charac-
teristic of the tropical and subtropical countries and
reaching the maximum of its development in South
America, while in the northern continents it is relatively
poorly represented. Lizards are, as a rule, carnivorous,
and since they destroy insects injurious to vegetation, they
may be counted as beneficial to man.

Anolis2 is one of the family Iguanidae,3 a large group of
lizards characteristic of the Western Hemisphere. The
family is known by the thick tongue, by a large scale
in the middle of the head in front of the eyes, and by the
fact that all four legs are Avell developed. The genus
Anolis contains eighty tropical species. Our species lives
in pine woods from the latitude of Tennessee south to the
Gulf and the island of Cuba. Its graceful form and bright
colors make it one of the most beautiful of lizards. It

1 A key to the four orders of Reptiles will be found in the Appendix to
this Chapter, page 280.

- Atwli, native name. 3 Native name,

268

THE LIZA It I) AND ITS ALLIES 269

lives on trees, eats insects, is not timid, can live well in
confinement, and, like the chameleon of Europe, has the
power of changing its colors from bright green to dirty
brown. Besides Anolis we have various other lizards of
the family Iguanidre. The horned toad of the Southwest,
which has a broad, flattened body and long spines on the
head, and lives in dry, sandy places, is a familiar object.1
In the South Central and Southern States lives the elon-
gate " swift " of varying color, often with black, irregular

FIG. 251. — Phrynosoma, the horned toad. Photo, by E. R. D.

cross bands above, with iridescent colors on the throat of
the male, and with large, strongly keeled scales and a
slender tail. The largest of the Iguanidse is the " leguan *
of the West Indies and South America, which gains a
length of 1.75 metres, or over five feet.

The family Varanidae,2 or water-lizards, contains the
largest known lizards. The Nile varanus attains a length
of nearly tAvo metres. It lives on the rivers of Africa,
feeds on small Crustacea, birds, birds' eggs, frogs, fish, and
occasionally also on young crocodiles and crocodile eggs.

1 Fig. 251. 2 Latinized from the Arabic word waran, lizard.

270

ZOOLOGY

The ancient Egyptians regarded these crocodile-like lizards
as the greatest enemies of the crocodile.

The Lacertidae,1 which are common in middle and south-
ern Europe, are agile, harmless creatures, often of bright
colors, and are commonly and favorably known. The more

FKJ. 252. — Lacerta viritUx, the green lizard of Europe. After Brehin.

abundant are the " green lizard" (Fig. 252), the ''sand-
lizard,"' and the "wall-lizard" of the Latin countries.

The Helodermidae include the largest lizard of the
United States, the so-called kt> Gila monster," which in-
habits New Mexico, Arizona, and the country southward.
The lizard is colored brown, with reddish spots and numer-

1 From lacerta, lizard.

THE LIZARD AND ITS ALLIES

271

ous yellowish punctatipns (Fig. 253). It is nocturnal in
its habits and its bite is very poisonous, although not often
fatal to man.

The family Anguidae, or slow-worms, includes the famous
glass-snake or joint-snake of the South. This snake-like
lizard has no legs, or only rudiments of the hinder pair.
It is noted for the ease with which it breaks in two when

FIG. 253. — Heloderma, the Gila monster. About two-fifths nat. size.

From Brehm.

struck or lifted by the tail. This result is due to the fact
that, as in certain other lizards, the vertelme of the tail are
unossified along the middle plane, so that they separate
at this point upon the slightest blow. The muscles of this
species seem also to be arranged so as to facilitate sepa-
ration. In Europe there is a lizard of this family, the
so-called u blind- worm " (having, however, well-developed

272 ZOOLOGY

eyes), which is found in retired localities, from which it
comes out, especially in the evening, to capture earth-
worms and slugs.

The Chameleon famed in literature comes from Africa.
Its change of color depends upon the possession of several
layers of different color in the skin, which layers can be
separately expanded or contracted as required, as a result
of which some one color comes to predominate. It cap-
tures insects, a habit which is facilitated by its power of

FIG. 2r4. — Chameleo, the chameleon. From Leunis.

protruding the tongue to over half the length of its body
and bringing the sticky end in contact with its prey. The
protrusions and retractions of the tongue are effected witli
marvellous rapidity (Fig. 254).

While in point of size the lizards of geologically recent
times are inconsiderable, those of former epochs were
huge. These former or fossil lizards were most charac-
teristic of the middle life era or the Mesozoic age. They
belong to three main groups; namely, swimming, walking
or wading,1 and flying lizards. The swimming lizards were

1 Fig. 254.

THE LTZART) AND ITS ALLIES

070

_ i • >

sometimes over 10 metres long% and had feet modified

as paddles. The land lizards were elongated, three-toed,
carnivorous reptiles, with hollow leg bones like birds. In
the flying lizards, a strong compact body was provided
with hollow, air-filled bones, and locomotion was effected
by a huge membranous expanse stretched between the

FIG. 255. — Hadrosaurus. From reconstruction model. Osborn, " Kept.

Amer. Mus. Nat. Hist."

elongated posterior finger, the trunk, and the hind legs.
The spread of the wing was about three feet.

The Chelonia,1 or turtles, form an order distinct from
the lizards. They are characterized by a depressed form,
a bony case, and toothless jaws. Like other reptiles, they
are most abundant in tropical countries, since the high

turtle.

274 ZOOLOGY

external temperature compensates in a way for the insuf-
ficiency of the mechanism for maintaining from the inside
a high blood temperature. Turtles are abundant in
Africa, and are much commoner in North America than
in Europe. Three families of Chelonia may be distin-
guished. A short account of each follows.

The family Chelonidae includes certain marine turtles.
Turtles live in all oceans and may acquire a weight of as

Fi<;. 2")ii. — Hawkbill-turtle. Much reduced. From Brehra.

much as one thousand pounds. The green-turtle, used in
making soup, occurs on the Atlantic coast as far north as
Long Island. From the hawkbill-turtle (Fig. 256) comes
the tortoise shell used in certain ornaments. In the
leather-back the shields are incompletely ossified.

The family Trionychidae l includes our soft-shelled tur-
tles, which live in rivers or ponds of the Mississippi valley
and the Gulf drainage basin (Fig. 257).

1 rpt's, tliriec ; 6w£, claw.

THE LIZARD AND ITS ALLIES

275

The family Testudinidae l includes the hard-shelled,
fresh-water and land tortoises. < )ur snapping-turtle is
distributed from Canada to equa-
torial South America. It feeds
on fish and lays from forty to fifty
eggs, which it buries at a depth of
about a metre. The alligator
snapper of the Gulf States attains
the length of a metre, and is re-
garded as the " most ferocious and,
for its size, the strongest of all
reptiles." The box-tortoises oc-
cupy the northeastern and central
parts of North America. They
are well known by the fact that

the body is short and high, the FIG. ir>7. - Trionyx, three-
plastron is provided with a mov-
able hinge, and the carapace is
colored black and yellow.2 Other

clawed turtle of the Mis-
sissippi valley. Reduced.
From Leuuis.

FIG. 258. — Tcrmpene Carolina, the box-tortoise.

by AY. H. C. P.

1 From tcst«, a shell.

Photo, of living' auimal

2 Fig. 258.

ZOOLOGY

common tortoises of the eastern United States are the musk-
turtle, told by a strong odor of musk ; the painted turtle,
of greenish black color and with marginal plates marked
with bright red ; the speckled tortoise, black with round
orange spots ; and the wood tortoise, with keeled shell,
and plates marked with concentric stria3.

The order Ophidia : comprises the snakes, characterized
by the elongated body without appendages, and by the

FIG. 259. — Eutfenia, garter-snake, dorsal view. Photo, by E. R. D.

absence of eyelids. Like other reptiles, the snakes are
chiefly tropical, but inhabit also the temperate zones. They
feed on living animals.

The family Colubridae 2 includes the great majority of
our common non-venomous snakes, such as the garter-
snake,3 water-snake, black-snake, milk-snake, and spread-
ing adder. Allied are the boas of South America and the
pythons of India, which attain the length of six metres or

c!0ts, serpent.

2 coluhra, serpent.

3 Fig. 259.

THE LIZARD AND 77\s ALLIED

more. Not being' poisonous their bite is not dangerous,
l>ut they attack large birds and even medium-sized mam-
mals and crush them to death in the folds of their body.

The family Elapidae : includes the large venomous ser-
pents of the East, the cobra of the East Indies, and the asp
of the Egyptians. The bite of these serpents is quickly

m \

i \ , i

IR^^fevfck

BMMb.

Fi<;. 2HO. — Elapx coralluia, a harlequin snake of South America allied to the
l)ead-snake of the South. From " Standard Natural History," after Brehin.

fatal to man. To this family belongs also the bead-snake
of our Southern States, which is however harmless (Fig.
260).

The Crotalidae 2 include the rattlesnakes, characteristic of
America.3 Of this family the most dangerous is the water-

. an unknown snake of the ancients.

/, clapper. 3 Figs. 261, 262.

278

ZOOLOGY

FIG. 2(il. — Crotalus, the rattlesnake. Photographed as the snake was about
to strike. Taken in Ari/ona and kindly lent by H. ~\V. Menke, Chicago, 111

FKI. 2(!2. — The rattlesnake. The recoil after striking. Photographed in
Arizona and kindly lent by H. AV. Menke.

Note in both figures the elevated rattle, toward the right.

THE LIZARD AND ITS ALLIED 27!)

moccasin or black moccasin, which inhabits the Southern
States, and give;; no warning noise as does the rattlesnake.
The copperhead of the eastern half of the United States is
also dangerous, but is mostly confined to wooded, moun-
tainous regions. The rattlesnake was once common over
the whole of the Northern States as far west as the Rocky
Mountains, but it is now nearly exterminated in well-
settled districts. Related to these are the venomous
vipers of Europe.

The order Crocodilina contains only some twenty species,
distributed in three genera. The gavial is the crocodile

FIG. 2b'o, — Head of Allii/ator ini.^f.^ippieiifiis, the Mississippi alligator.

From Leunis.

of the (ranges River. It captures even large mammals
and man. The crocodile in the strict sense is found in the
Nile and other African rivers, in certain countries on the
western border of the Pacific, and in northern South
America, Central America, and the Antilles. The American
alligator, which has a different arrangement of the denti-
tion from the crocodiles, occurs in seven slightly differing
species, all of which are South American excepting the alli-
gator of our Southern States. It feeds on fish, and attacks
horses and even man (Fig. 2(53).

280

ZOOLOGY

APPENDIX TO CHAPTER XVIII

KEY TO THE FOUR ORDERS OF REPTILES

«i. Trunk enclosed in a case composed of a dorsal and
a ventral shield (carapace and plastron) ; jaws
without teeth .......

«.j. Without encasing shields ; teeth on jaws.

b\. Teeth in special cups or alveoli ; 4 legs ;

cloacal opening a longitudinal slit
f>-2. Teeth not in special alveoli ; cloacal opening a

transverse slit,
fi. Shoulder girdle and sternum present ;

eyelids usually present

c-j. Shoulder girdle and sternum absent ; eye-
lids absent ; no feet ....

Chelonia

Crocodilina

Sauria

CHAPTER XIX

THE ENGLISH SPARROW AND ITS ALLIES

THE term "English' sparrow is somewhat of a mis-
nomer, for at the time it was introduced into our country
this bird ranged over all Europe, where it is known as the
Jwuse sparrow. The history of the spread of this bird
shows us in a vivid way what are the successful qualities
among birds. Originally this sparrow was confined to
middle Europe, and probably made its way into Germany
at the time of the Romans. It has since swept all over
Europe, including the British Isles, and has penetrated
even into Siberia. It has crossed the Mediterranean and
is found along the Senegal River, and, probably through
human agency, has penetrated to the Cape. It lias been
transplanted voluntarily by man to North America,
Australia, and Java. It seems to occupy among birds the
place taken among mammals by the rats. Crafty, pugna-
cious, obtrusive, thieving, dirty, it has become a nuisance
wherever it has penetrated. But just these pushing quali-
ties, combined with small size, great hardiness, a universal
diet, and immense fecundity, have enabled it to make its
Avay against all competitors. Its introduction into America
can only be regarded as a deplorable blunder.

Spread of English Sparrow in America.- -The first im-
portations of the house-sparrow (Passer domest.icus) to
North America were made at Brooklyn, New York, in 1850

281

282 ZOOLOGY

and 1852. The second importation survived and multiplied.
Subsequent importations were made to Maine, Rhode
Island, and Pennsylvania, so that by 1870 the sparrow
was firmly established in the eastern United States. From
this time on the sparrow spread at a rate unparalleled by
any native bird. By 1886 it had spread as far west as
Kansas, and had established colonies at Salt Lake City,

San Francisco, and other outlying regions ; and through-
out this territory it occurred in great abundance. Since
then it has penetrated west to the Rocky Mountains, and
south to Texas. This extraordinary spread has been due
to several causes. As already suggested, the bird can
adapt itself to various climatic conditions, and its fecundity
is very great. Thus in our Southern cities there are from
five to six broods a year, and from four to six young in
each brood. Assuming that twenty-four young, half of
them females, are produced by a pair each year, and that
all the females breed when one year old, and successively
for ten years, and that there are no deaths, then in the
tenth year 138,000,000,000 individuals will have been pro-
duced from the original pair. To the realization of the
possible maximum of reproduction there are, however,
many checks, especially the destruction of birds by ac-
cidents, disease, and beasts and birds of prey.

Food of English Sparrow. - The house-sparrow was in-
troduced for the purpose of destroying or holding in check
the wt canker-worm" and the various other caterpillars which
destroy our fruit, forest, and shade trees. There is much
doubt, however, whether the house-sparrow is at all effi-
cient in the way of destroying insect pests, while it is
quite certain that it fights with and drives away our
native insect-eating birds. More important still, it de-

THE ENGLISH SPARROW AM) ITS ALLIES 283

stroys large quantities of grain in the field, as well as
many kinds of garden produce, so that, on the whole, the
English sparrow must be reckoned destructive to agri-
culture. Of late years it has come into our Southern
markets as a substitute for the rice-bird.

Increase of Exotic Species. - The extraordinary spread
of the English sparrow after importation to this country
is not wholly explained by its large fecundity; for although
equally reproductive in Europe, it ^increases less rapidly
there than here. Also it is not due to any peculiarity of
our country, for the bird is a similar pest in Australia.
Similar facts concerning the spread of other animals lead
us to conclude that it is the new country which permits
the rapid spread and consequent destructiveness. Thus
when the cabbage-butterfly (Pieris rapce) was brought to
this country it spread with such rapidity that, starting in
1860 at Quebec, it has now spread all over the United
States as far as the Rocky Mountains. Again, the grape-
vine insect pest, Phylloxera, a native of this country, but
not particularly destructive here, has been accidentally
transported to France, and there it lias wrought great
havoc in the vineyards. Another instance, this time of
an aquatic animal, shows the same result : the periwinkle,
Littorina littoria, now the commonest snail on the seashore
north of New York, has migrated down the shore from
Halifax since 1868. This old species in the new country
lias almost driven out the other shore mollusks, to such an
extraordinary degree has it multiplied. Now why should
animals in a new country develop with such unusual rapid-
ity ? It is because coming into a new country they have
left behind them their natural enemies, and there has not
yet been time for them to acquire new ones. Eventually

284

ZOOLOGY

the new enemies are gained or their old ones overtake
them, and then the numbers of the exotic form become
reduced ; a new equilibrium becomes established.

The English sparrow belongs to the family Fringillidae,
which includes sparrows and finches. This is a large

Fid. l'<)4. — The American crossbill (Lo'j-'m

family, comprising over five hundred species, found in all
parts of the world, excepting, originally, Australia. In
the United States this is the largest family of birds, com-
prising in most places about one-seventh of the species.
Among common or striking native Fringillidse may be

THE ENGLISH SPARROW AND TTs ALLIES

mentioned the crossbills,1 yellow-bird, vesper-sparrow,
white-throated sparrow, tree-sparrow, chipping-sparrow,2
snow-bird, song-sparrow, fox-sparrow, chewiiik, cardinal
grosbeak, rose-breasted grosbeak, and indigo-bird. Most
of these birds are known to every country boy.

The family of Turdidae, <>r thrushes, includes several
common American birds, — the robin, abundant about

FIG. 2<!5. — Cliipping-sparrow (tii>iz<>ll<i Nn<-i<tft*).

houses during the summer but for the most part migrat-
ing south from New England during the winter : the wood

o o o

or song thrush,8 one of our finest songsters; the bluebird,
one of the earliest of our migrants, with u the sky on its
back and the earth on its breast."

The family of Sylviidae comprises the " warblers " of the
Old World. Here belongs the European nightingale. Its
common representative in this country is the ruby-crowned
kinglet (Fig. 267).

1 Fig. 204.

2 Fig. 205.

Fig. 2(50.

28(3

ZOOLOGY

The family of Paridae includes the titmice, or tits and
nuthatches. The tits are chiefly Old World birds, but we
have a common representative in the black-capped chicka-
dee, well known from its cheerful whistle. In this family

Fn;. 2(i(i. — Wood-thrush (Turiltts

belong the nuthatches which run over tree-trunks, head
up or down, indiscriminately (Fig. 268).

The family of Certhiidae includes the little brown creeper
which runs over tree-trunks much as the nuthatches do
and uses its tail-feathers as props against the tree-trunk
(Fig. 2l JO).

THE ENGLISH SPARROW AND TTS ALLIES 287

The Troglodytidae, or wrens,
are characteristic of South
America, but some have spread
into North America and north-
ern Europe. Our house- wren,
which is a near relative of the
European house-wren, is an ac-
tive little brown bird, with a
sharply bent-up tail.1 In this
same family belong the mock-
ing-birds, the centre of whose
distribution is Central America,
the \Vest Indies, and the south-

FIG. i>r>7. — Golden-crowned king-

let (R

ern United States. The
large brown thrasher and
the cat-bird are familiar
over the country. The
mocking-bird does not

o^et far north into New

England. It is regarded
by many as superior to
the nihtinale as a

snger.

FKJ. 2(iS. — White-breasted nuthatch (S:tta
carolinensis) .

The family of Mnioti-
lidae, or " wood - war-
blers," is the peculiar
glory of America. It

1 Fig. 270.

ZOOLOGY

contains numerous small, mostly brilliantly colored birds,
which migrate. Although a few of .them- -like the red-
start, the Maryland yellow-throat (Fig. 271), the redpoll
warbler, the chestnut-sided warbler, and the yellow war-
bler- - are abundant, few of the thirty -five or forty Eastern

. l'(>it. - - Brown creeper
( Ccrithia familiar if) .

FIG. 270. -- House-wren (Troylodyt.es aedon).

species can be said to be commonly known except to
careful observers of birds ; for during the migrations
they hide in thickets, and are extremely shy.

The Vireonidae include the vireos, or greenlets, bright,
handsome, and exclusively American birds. The com-

THE ENGLISH SPARROW AND ITS ALLIES 289

monest species are the red-eyed vireo (Fig. 272) and the
yellow-throated vireo.

The Laniidae, or shrikes, are of world-wide distribution.
They are vigorous, pugnacious birds, which have the habit

Fi(i. 271. — Maryland yellow-throat (_G?ot-hlypis trichas).

of impaling grasshoppers and other small animals upon
thorns, and leaving them there. In Germany there is a
tradition that the shrike daily impales nine victims, and it
is hence commonly called Neuntodter, or u ninekiller." The

290

ZOOLOGY

FIG. 272. — Red-eyed vireo (Vireo

FIG. 273. — Great northern shrike (Lanlus

THE ENGLISH SPARROW AND ITS ALLIES 291

impaling seems to be done chiefly in the winter time, and
apparently has for its purpose the storing of food against
possible famine. Among birds frequently destroyed by
them is the English sparrow, and it has been suggested that
the shrikes should be encouraged to live in parks of cities

FIG. 274. — Cedar waxwing (Ampelis cedro

infested by sparrow pests ; but unfortunately the shrikes
do not confine themselves to this intruder. We have two
species of shrikes, a northern (Fig,, 273) and a southern.
The Ampelidae, or waxwings, are found over the Northern
Hemisphere. They are migratory, go in flocks, feed on

9Q9

«il«7 —I

ZOOLOGY

insects and fruits, and chatter rather than sing. Our
commonest species is called "cedar-bird " (Fig. 274).

Fio. 275. — Barn-swallow

The Hirudinidae, or swallows, are found over the world.
They are powerful fliers, and are insectivorous. Formerly
all of them bred in boughs, cliffs, and hollow trees, and

some species still retain these
habits. The best-known species
are the bank-swallows, which,
living in colonies, form numer-
ous holes in railroad cuts and
sandbanks in general ; the
white-bellied swallow, abundant
about water ; and the barn-swal-
low (Fig. 275), with a chestnut

Fi<;. 276. —Nests of barn-swal- & .

low. Photo, by D. and s. belly, which builds its nest in the

rafters of our barns (Fig. 276).

The Tanagridae, or tanagers, are exclusively American,
and belong especially to the tropics. They live in the

THE ENGLISH 8PAKKO1V AND ITS ALLIES 293

woods, and feed on berries and fruits. The northernmost
member of the family is the scarlet tanager of the eastern
United States (Fig. 277).

The Icteridae include numerous species with different
habits. These are also confined to America, and are
especially abundant in the tropics. They feed, for the

FIG. 277. — Scarlet tanager (Piranya erythomelas) .

most part, on seeds. The commonest representatives are
the crow blackbird,1 of large size and iridescent plumage ;
the Baltimore oriole, which weaves a hanging nest ; the
orchard oriole, with less orange than the preceding; the
large meadow-lark, brownish above and yellow below;
the red-winged blackbird ; the cow-bird, which builds no
nest but lays its eggs in the nests of various small birds ;

1 Fig. 278.

294

ZOOLOGY

and the " bobolink," as it is called in the North, Avhose song
is the merriest of all birds. In the South, whither the
bobolink migrates in the winter, it is a great pest in

FIG. 278. — Purple grackle (Quiscalus quisculci).

the rice-fields, and is known as the u rice-bird." It is
slaughtered there as a game-bird.

The Corvidae include the crows and their allies, all of
them birds of large size. The crow, the raven of the West
and of Europe, and the blue jay (Fig. 279) are the com-
monest North American species of this family.

THE ENGLISH SPARKOW AND ITS ALLIES 295

The Alaudidae, or larks, are a family chiefly of Old World
birds of dull color, building a rough nest on the ground,
and feeding on seeds and insects. The skylark of Europe
is renowned as a songster. In this country we have one

;' ' A V v

S -T— /

! ' " - f

J U |

FIG. 279. — Blue jay (Cyanocitta cristata).

representative of the family, the horned lark, found also
in Europe.

The Tyrannidae, or flycatchers, are an exclusively Ameri-
can family, feeding on insects. The best-known represen-

296

ZOOLOGY

tatives are the courageous king-bird (Fig. 280), the wood
pewee (Fig. 281), and the water-loving phcebe.

Fi<i. '2X0. — Kingbird

* tt/r<nnitis).

FIG. 'J8L — Nest of pewee. Photo, by D. and S.

THE ENGLISH SPARROW AND ITS ALLIES

We will now pass in brief review the principal Orders of
Birds other than Passeres. The Psittaci include the
parrots and cockatoos. In the cockatoos the feathers of
the head are elevated to form a crest. In the parrots
there is no such crest; in one subdivision the tail is long;
in a second, very short. The representatives of this

FIG. 282. — Conurus carolinensis, the
Carolina paroquet. One-fifth nat. size.
After Wilson.

family are found almost exclusively in the tropics, in
Brazil, the Moluccas, and in Australia. In general, these
birds have a loud voice, and certain species may be trained
to articulate words and combine them into sentences.
There is only one parrot native to the United States -
the Carolina paroquet (Fig. 282j. This formerly occurred

298

ZOOLOGY

north to the Ohio River, but it has been within recent
years practically exterminated by plumage hunters.

The Raptores include eagles, hawks, and falcons ; the
vultures; condors; and owls. These birds feed chiefly on

FKJ. lifSo. — Sharp-shinned hawk (Ac-
cipiter velox) .

FIG. 1^84. — Screech owl (Meya-scoj>s

asio) ,

birds and mammals, which they capture alive in their
claws or beaks ; a few live on carrion. They occur in all
parts of the globe. The bald eagle, used as a symbol of
the Republic, is the commonest of our eagles. Among

THE ENGLISH SPARROW AND ITS ALLIES 299

our hawks, the sparrow-hawk, which is only about the
size of the robin, is one of our commonest; others are
the sharp-shinned hawk, which kills birds almost ex-
clusively, and is especially destructive to poultry,1 and
Cooper's hawk, which is also destructive to birds. These
two hawks have practically no redeeming qualities, ex-
cept the fact that they prey upon the English sparrow.
The vultures are represented in our fauna by the
turkey-buzzard, which, like other members of the family,
feeds on carrion. The European and African vultures
even exceed the turkey-buzzard in size. The condor
is the largest of the American Raptores. It preys even
upon live sheep and calves. The owls, which live in dark
holes and feed upon small mammals at night, are found
over the globe. Our commonest species is the reddish
gray screech-owl.2 The great horned owl is an inhabitant
of wooded tracts, and is destructive to poultry and small
mammals. The snowy owl is one of the handsomest of all
owls, and is frequently seen stuffed in houses in Europe
as well as in North America.

The Scansores include the toucans and cuckoos on the
one hand and the woodpeckers on the other. The toucans
are characterized by an enormous bill, which in extreme

cases is as long as the rest of the bird. It would be ex-
tremely heavy were it not filled with air spaces of great
extent. These birds inhabit Brazil. The great bills are
of use in feeding on fruits. Filling the place in the Old
World of the toucans of the New are the hornbills of
Africa and Asia, which are likewise frugivorous. The
cuckoos are typically represented by the Old World
cuckoos. Like our own cow-bird, they have the peculiar

iFig. 283. -Fig. 284.

300

ZOOLOGY

habit of laying their eggs in the nests of other birds, espe-
cially insectivorous birds, where they are brooded and the
young are fed by the foster-mother. Our native cuckoo,
however, broods its own eggs, and is a useful insectivo-
rous bird. The kingfishers are also placed in this group.

sjSife^r- > .,-•'

Fm. 2Hf>. — Belted kingfisher (O/-//fc a

They are especially an Old World family, but one genus,
Ceryle, has found its way into North America and even
into South America. These birds feed chiefly on fish, and
they have gained a compact oily plumage to prevent them
from getting wet when they plunge for their prey. Our
species is known as the belted, kingfisher (Fig. 285).

THE ENGLISH 8PA1U1OW ANT) ITS ALLIES 301

The woodpeckers include for the most part arboreal
birds which feed chiefly on insects and have loud, harsh
cries. The common idea that they are sap-suckers and
destructive to trees seems to be true only of one of our
species — the yellow-
bellied woodpecker.
The heavy, long bill
enables woodpeckers
to peck holes in trees
for wood-eating in-
sects, and the long,
barbed, protrusible
tongue aids in remov-
ing the prey. Our
commonest woodpeck-
ers are the golden-
winged woodpecker, or
flicker,1 the red-headed
woodpecker, the hairy
woodpecker, and the
d o w n y woodpecker.
An interesting ques-
tion concerning the
golden -winged wood-
peckers of the East and
Southwest is whether
they hybridize where
their areas of distribution overlap.

The Cypselomorphae include the humming-birds, swifts,
and goat-suckers. The humming-birds are mostly small
species, limited to our hemisphere, and characteristic of

Fi(i. 28(i. --Flicker

auratns).

Fig. 286.

302

ZOOLOGY

the tropics. One species, the ruby-throated humming-
bird, reaches New England and Canada. These usually

brilliantly colored
birds feed on insects
and nectar, which they
gather from flowers.
They fly with great
swiftness, nest in trees,
and lay only two white
eggs (Fig. 287).

The Swifts have a
broad gape, and no
bristles at the base of
the bill. They have
habits much like swal-
lows, and are found
especially in the warm
parts of the world.

FKJ- 287. — Ruby-throated humming-bird :. .

(Trochiius coinbris). Most species ot this

family have salivary

FIG. 288. — Nest of chimney-swift. Photo, looking down chimney, by D. and S.

THE ENGLISH HP ARROW AND ITS ALLIES 803

glands, whose secretions aid in cementing the nest. Our

common representative of this group is the chimney-swift,

or chimney-swallow.1 Certain Chinese species make nests

entirely of the mucilaginous secretion of the saliva rv

glands ; these constitute

the edible birds'-nests

of the Chinese. The

goat - suckers include

night-flying birds, with

exceedingly broad gape

and insectivorous habits.

The night - haAvk of

North America, and the

whippoorwill, noted for

itii characteristic night

; '\

cry, are familiar ex-
amples.

The order Columbinae
includes the pigeons and
allies, characteristic of
the Eastern Hemisphere.
The most interesting
species of the group -
the dodo and the soli-
taire, formerly inhabit-
ants of the islands of
Mauritius and Rodri-
guez, r e s p e c t i v e 1 y -
have become extinct within historic times through the
settlement of these islands by white men. These birds
had rudimentary wings and tail. Their nearest living

FIG. 2S!). — Passenger pigeon (Ectop/sfes
migratorius) .

1 Fig. 288.

804

ZOOLOGY

ally seems to be the u maiiu-mea1 " of the Samoan Islands.
The pigeons proper are represented in North America by
three wild species (Fig. 289). The domesticated pigeon,
Columba livia, is a native of southern Europe or western
Asia.

The order Gallinacei includes a number of terrestrial
birds of large size, especially the grouse or partridges, the
pheasants and common fowl, the guinea fowl, and the tur-

FIG. 290. — Ruffed grouse (Bonaxa

keys. On account of their large size and well-flavored
flesh, they are much used as human food. The grouse
of America include the familiar kb bob-white ' or quail,
which is undergoing a rapid extermination in populous
regions ; the Canada grouse, which does not occur south
of New York; the ruffed grouse of the Eastern States;2
and the prairie chicken of the Great Plains, which has
also become almost exterminated. In Europe the large

1 Red-bird.

2 Fig. 290.

THE KXfJLffUf RPAHHOir A.\I) ITS ALLIES 30")

" capercallie v and the blackcock are favorite game-birds.
The pheasants are characteristic of southern Asia and
China; they comprise some of the most brilliantly colored
and greatly ornamented of birds, such as the peacock and
the golden pheasant. Here also belong our barnyard
fowl, derived from a \vild species, Grallus kmikiva* inhabit-
ing northern India, the Hast Indies, and the Philippines.
The guinea-fowl is a native of Africa, where it goes in
large flocks and is difficult of approach. The turkeys
are North American birds. The wild turkey formerly

«/ i/

occurred over all the United States and Mexico. It was
first taken to Europe in 1524, was domesticated there, and
now occupies much of its former habitat as a domesticated
fowl. From this brief view we see that the family of (ial-
linacei is, for man at least, one of the most important
families of birds.

The Grallatores, or waders, include a great number of
shore birds known as plovers, sandpipers, snipes, rails,
cranes, herons, and storks. The plovers walk and fly
along shore, picking up worms, mollusks, and amphibians;
the golden plover and the killdeer are well-known game-
birds. The snipes are found in meadows or, less com-
monly, in woods. One of the most common is the spotted
sandpiper, also called •"• tip-up ' from its rocking move-
ments (Fig. 291). It is seen walking around small pools
of water by the roadside or in fields. Along the coast
are found woodcock and large snipes. Among the herons,
our great blue heron attains a length of four feet and is
a notable resident of swampy regions; the egrets have
been practically exterminated to meet the demands of
milliners ; the bittern is still common on tide-flats.

The Natatores, or swimmers, comprise the ducks and

306

ZOOLOd Y

geese, the pelicans, the petrels, the gulls and terns, and
the divers. Of the geese, the wild goose, or Canada goose,
is most commonly seen in its migrations. Of the native
ducks we have many kinds, almost all rapidly disappear-
ing before the "sportsman." The pelicans are large fish-
eating birds, with a huge bag-like lower bill. In this
country the white pelican is not uncommon. The large-

Fi<;. 2D1. — Spotted sandpiper (Act it is macularia).

winged petrels follow in the wake of coastal vessels. The
terns, which are slender birds with a straight bill,1 were
once abundant along our coast, but have been decimated to
" ornament" bonnets. The gulls, which are heavier than
the terns and have hooked bills, are still abundant over
all bodies of water. Finally, the loons are large birds,

1 Fig. 292.

THE ENGLISH SPARROW AND ITS ALLIES 307

powerful fliers and swimmers, which are found in the
lakes of the Northern Hemisphere. They are quick
divers, and can swim under water for a considerable
distance.

The order of Cursores includes the African ostrich, the
American ostriches or rheas, the cassowaries of the East
Indies, and certain wingless birds of New Zealand (Ap-

Fi(i. l^i)2. — Common tern (titn-ita hirundo).

teryx1). These are regarded as the most lowly developed
of the birds ; the vanes of their feathers are not united,
but separate to form a sort of hair-like covering to the
body. The African ostrich is the largest living bird. It
wanders in families or flocks in the deserts of Africa, and
feeds on grass, grain, and small animals. It also swallows
undigestible matters, such as stones, which probably aid

1 Fie. 293.

SOS

ZOOLOGY

it in triturating its food. The nest consists of a hollow
scooped out of the earth, into which about thirty eggs are
laid. Ostrich feathers are used for ornament, and so
important is the commerce in these articles that ostriches

FIG. 293. — Apteryx australis with egg. From a specimen in the Royal College
of Surgeons, London. From Parker and Has well, " Text-book of Zoology."

are extensively farmed in South Africa. When reared in
captivity the eggs are hatched in an incubator, and the
young carefully fed. The feathers are cut off and not
pulled out, so that the operation of gathering the feathers
is a painless one.

THE ENGLISH SPARROW A XI) ITS ALLIES 300

Bird Migration. — The birds of any territory may be
classified on the basis of their residence into four groups :
permanent residents, winter residents, summer residents,
and transient visitants. In New York the permanent
residents are represented by the screech-owl, the crow,
and the gold-finch. Winter visitants are represented by
the snow-bird and white-throated sparrow ; summer resi-
dents by the wood-thrush, cut-bird, yellow warbler, bobo-

J v

link, and barn-swallow ; transient visitants by most of the
warblers, the fox-sparrow, and white-bellied swallow. As

this classification indicates, the bird fauna of any place is,
to a great extent, shifting from season to season. In the
spring at any latitude many species are seen passing far
north, and in the autumn passing south again. Tem-
perate as well as southern latitudes receive in the winter
time the southern edge of a more northern fauna. Thus
Sfeese and ducks are forced by the universal ice of the

O v

Arctic winter to go to regions of open water, at least.
Many kinds of birds which spend the winter in the South
come North to breed. For example, the bobolink is found
nesting in the New England fields in summer, and is then
altogether absent in the South. Lithe fall this bird is not

found in New England, but occurs in the Gulf States as

the rice-bird. The cause of this migration on the part of
birds breeding in the North is the need of food. Insectiv-
orous birds, especially, could not obtain food enough in
the North in winter.

Migration Routes. — It is known that many species
which migrate even great distances travel along well-
defined paths. In Europe the paths of the shore migrants
have been carefully mapped out. It appears that these
birds follow the shore line very exactly, except in some

810 ZOOLOGY

cases in which it can he demonstrated that their paths are
along ancient shore lines. As Wallace says : " It is easy
to see how the migrations that had once taken place over
continuous land would be kept up first over lagoons and
marshes, then over a narrow channel, and subsequently
over a considerable sea, no one generation of birds ever
perceiving any difference in the route." The migration
routes of North America have not been well studied. The
Atlantic coast is one line ; the Mississippi valley, for-
merly, no doubt, an arm of the sea, is another route along
which even sea-birds now migrate. The question how
birds recognize and are able to follow their migration
routes, is a difficult one ; they seem to have a marvellous
sense of direction. There is great need of a more perfect
knowledge of migration phenomena in North America.
Every one who has learned to distinguish accurately the
species of birds can contribute to this knowledge by keep-
ing records of the time of appearance of migrants in the
spring and the fall. The American Ornithologists' Union
has for many years solicited observations on this subject
from voluntary collaborators.

Bird Flight. - The difficulties which must be overcome
in order to fit birds for flight are, first, that of sustaining
the heavy body in a medium of such low specific gravity as
the air and, secondly, that of progression in this medium.
To diminish the difficulty of sustaining the body, the
specific gravity is reduced to a minimum by great air-
spaces in the body, which exist even in the hollow bones.
The body is kept from being overturned in the air by the
position of the wings, which are placed high up on the
trunk while the digestive organs, breastbone, and breast
muscles are placed low. To aid locomotion, the general

THE ENGLISH SPARROW AND ITS ALLIES 311

form of the body is made conical, so as to offer little re-
sistance to the air, while, by varying the position of the
head, wings, and tail, the centre of gravity is quickly
shifted. In starting to fly, the bird sftiins an initial veloc-

o «/ * o

ity, if 011 the ground, by springing into the air, or if on a
tree, by combining the velocity due to gravity with a push-
ing from the limb ; but aquatic birds strike the surface of
the water with their wings. The best fliers have relatively
large, pointed wings. Three methods of flight are em-
ployed by birds when once in the air : («) stroking the air
with the wing; (£>) gliding or skimming ; and (c) sailing or
soaring. Some birds can use all three methods, and all
good fliers use the first two. In the stroke the wing moves
downward and forward, backward and upward, so that the
tip of the wing describes a QO; and the plane of the wing
constantly changes so as to push downward against the
air, and thus keep the bird up, and to push backward
against the air, and thus drive the bird forward. At the
same time, the wing must be brought back to its upper and
anterior position without offering great resistance to the
air. In gliding, the wings are spread, but are not flapped,
- progression depends upon an acquired velocity or upon
the wind. In soaring, the wings remain motionless, and
the bird does not lose its velocity nor tend to fall. Tne
way in which the bird is supported and carried along is
uncertain. It seems to depend upon certain favorable
currents in the air.

Birds, like insects, have the closest economic relations
with man. A few of them, chiefly belonging to the orders
of Natatores and Gallinacei, are very important as human
food; but most of them concern man on account of their
feeding habits, which are either favorable to man, as when

312 ZOOLOGY

noxious insects are destroyed ; or injurious, as when grain-
helds are ravaged or other birds are destroyed. Un-
questionably the vast majority of birds are commercially
advantageous to man. The Kaptores are only partially so,
for they feed entirely upon animal food, chiefly birds and
small (usually destructive) mammals. The bobolink and
the American crow, to be sure, together annually destroy
millions of dollars' worth of grain, yet during the breeding
season they both feed much upon insects. Outside of the
group Kaptores, there are few, if any, completely noxious
birds, and even many of the hawks are efficient destroyers
of insects. Legislation directed toward the destruction of
any kind of birds, excepting the English sparrow and the
Cooper's and sharp-shinned hawk, is quite as apt to do
harm as good.

Bird Protection. — Travellers in certain parts of Europe,
where the poverty and ignorance of the people have led
them to prey upon birds, have remarked on the desolation
of a birdless country. The natural enemies of insects
being destroyed, there is no adequate check to the destruc-
tion of vegetation by them and the beauty of a forest
landscape is missing. North America has been richly
provided witli a native bird fauna ; but within the last
few years it has become plain that most of our species are
undergoing reduction, and many are near extermination.
Careful inquiries recently made indicate that during the
past fifteen years the number of our common song-birds
has been reduced one-half, and the number of certain birds
prized as food or ornament has been reduced to one-fourth.
At the present rate, extermination of many species will
occur during the lives of most of us. The causes of this
destruction of birds are numerous. The most efficient

THE ENGLISH SPAKUOIV AND ITS ALLIES 313

cause is the shotgun in the hands of boys and thoughtless
men, and of those who gather birdskins to meet the demand
for bonnet "ornaments." Very great destruction is also
caused by egg-collectors, who annually gather scores of

FIG. 294. — Hesperornis regalis. The restored skeleton. After Marsh.

thousands of eggs, often of rare birds. The disastrous
results of killing birds need only to be appreciated in
order to put a stop to this destructiveness.

Extinct Birds. - The destruction of species of birds
goes on fast enough without the more efficient aid of man.

314

ZOOLOGY

We know of .species which have become extinct within
recent times through the introduction of new enemies
among them. Such was the fate of the dodo. Then
remains have been preserved to us in the rocks of species
which lived in very remote periods. The oldest known
fossil bird, Archeeopteryx, of the Jurassic age, had a long
tail like a lizard ; but feathers, which are only modified
scales, were present even in this oldest known bird. In
the Cretaceous rock deposits of the Great Plains there
have been found fossil birds with teeth set in sockets or
grooves, precisely as they are to-day in reptiles (Fig. 294).
These remains show us in the clearest manner that birds
have been derived from reptiles. Indeed, the two groups
are closely related anatomically, and are often united
under the name JSauropsida or lizard-like animals.

APPENDIX TO CHAPTER XIX

KEY TO THE ORDERS OF BIRDS

a\. Sternum with keel for insertion of flying muscles

[Carinatse].
bi. Toes more or less webbed or fringed, legs

used for swimming or wading.
Ci. Short legs, broadly webbed [Swimmers]
C2. Long legs, long, thin neck, and long beak

[Waders]

62- Feet not webbed, fitted for walking.
c\. With cere.

d\. Beak strong, and bent downward at

point ; perching feet ; flat nail
(?2- Beak not bent downward at point ;
short, cloven feet ; nail com-
pressed

Natatores
Gmllatnres

Gallinacei

Golumbinw

APPENDIX TO CHAPTER XIX 315

(}$. Beak hooked ; strong, sharp, hooked

claws ...... Raptures

d±. Beak shorter than high ; thick, fleshy

tongue Psittaci

c%. Without cere.

d]_. Beak long, often heavy ; tongue thin ;
stiff plumage with little down ;
metatarsus with half rings on
scutes; feet scansorial . . . Scansores

dz. Metatarsus with no scales or rudi-
mentary ones ; feathered in upper
part Cypselomorphce

ds- Metatarsus covered with lamina? or
scales, rarely feathered, usually
with singing apparatus ; feet not
scansorial, mostly migratory . Passcres

a-2- Sternum without keel [Ratitas] .... Cursores

KEY TO THE FAMILIES OF PASSERES OF NORTHERN UNITED
STATES, BASED OX D. S. JORDAN

«i. First of the 10 primaries more than f length of

longest of the others [Clamatores] . . . Tyraimidce

a*. First of 10 primaries short, rudimentary or ab-
sent ; musical apparatus highly developed
[Oscines].

b\. First primary short or spurious [primaries 10].
d. Tarsus booted ; rictus with bristles.

d\. Middle toe quite free from inner ;
birds of moderate size ; length
more than 15 centimetres.
e\. Wings when folded not reaching

beyond middle of tail ; no blue Titrdidaz

e-2- Wings reaching beyond middle

of tail ; ours chiefly blue . Saxicolidcu
d-2. Middle and inner toe connected at
base ; length less than 13 cen-
timetres

Cz- Tarsus scutellate in front.

di. Nostrils concealed by bristly feathers.

11(5

ZOOLOGY

€]_. First primary not more than i
length of second ; length less
than 20 centimetres,
/i. Bill as long as head ; wings

longer than tail

./•_'• Hill much shorter than head ;

wings about as long as tail

PZ- First primary more than 1 length

of second; length more than

20 centimetres

•/•:• Nostrils exposed or merely overhung

by feathers.
('i. Bill notched near tip.

J\. Tail longer than wings ; gen-
eral color gray or ashy
brown.

f/i. Bill very stout and deeply
notched and hooked ;
bird over 17 centi-
metres

f/-j. Bill neither stout,
notched, nor hooked ;
bird over 17 centimetres
</5. Bill very slender ; bird
under 17 centimetres .
/j. Tail shorter than wings ; gen-
eral color olivaceous .
('%. Bill not notched.

J\. Rictus with bristles.

i/ 1. Quills not barred ; length
over 20 centimetres .
(1-2.. Wing and tail barred ;
length under 18 cen-
timetres

./•> Rictus without bristles

Firsf primary about as long as second ; the

real lirst rudimentary, leaving apparently 9.

Cj. Bill triangular, depressed, as wide at base

as long ; gape twice as long as culmen

c2. Bill stout, conic, with convex outlines,

Par id a:,

Corrida:

Lioiiidce

Tnrdido:

Tvoglodytidw

Cei'tli iidf.c

Hir«d in idie

APPENDIX TO ('II APT EH XIX

317

edge of upper bill with lobes or nicks
near middle .....

Bill conical, corners of mouth drawn

down.

<li. Bill much shorter than head, usually
notched at tip or with bristles at
rictus ......

(/._.. Bill usually about as long as head ;

no notch at tip nor bristles at rictus

Bill not as above ; edge of upper bill

straight or very gently curved.

d\. Conspicuously crested ; bill trian-

gular, depressed, notched, and

hooked ; tail tipped with yellow ;

wings red-tipped ....

<7o. Nostrils concealed by bristly feath-

ers ; tarsus scutillate behind .
(?-. No crest ; nostrils exposed; tarsus
with sharp ridge behind formed of
union of two lateral plates.
e\. Hind claw twice as long as mid-
dle claw .....

f>.2. Hind claw not twice as long as

middle claw.

J\. Bill stout, compressed, hooked
at tip ; tail not blotched
with red or yellow . .
/o. Bill various; little, if at all,
hooked ; colors often brill-
iant .....

T<u><ujri<l<_c

FringillidcB

MotctcilHdcK

Vireonida1

CHAPTER XX

THE MOUSE AND ITS ALLIES

THE mouse belongs to the class Mammalia,1 character-
ized by having milk glands whose secretion is used to
nourish the young, and hair, which may be nearly or
quite absent as in the case of porpoises or whales.2

The distribution of the house mouse, from which the
different kinds of fancy mice have been derived, is now co-
incident with that of civilized man ; but in early times it
was limited to Asia. From Asia it made its way to Europe,
and thence by vessels to other continents. It was imported
to America (which has no indigenous members of the genus
Mus) by the early explorers. There have also been im-
ported to this country three other species of this genus, of
such size that they are commonly called rats. Of these,
the roof rat seems to have been imported by the early
Spanish discoverers to the Southern States, where it still
persists. It originated in Egypt. The second was the
black rat, believed to have been imported to America about
1544. It has existed from time immemorial in Europe : it
has a mild disposition, and from it the white rats we keep
as pets have been derived. The brown, or Norway rat,
has been the latest importation. The history of its migra-
tions has been written. Probably originating in central

belonging to the breast.

- A key to the orders of Mammalia will be found in the Appendix to

this Chapter, page 331.

318

THE MOUSE AND ITS ALLIES 319

Asia, it crossed the Volga in great troops in 1727, occupied
Russia in 1730, France in 1750, and Denmark about 1810.
Before the advance of this powerful and aggressive foe,
the black rat of Europe gave way, and became well-nigh
exterminated, although of late it is said to be reasserting
itself in Germany. The brown rat was introduced into
America in 1775, has spread over the whole country,
reaching the Paciiic coast about 1855, and, as in Europe,
has nearly exterminated the black rat.

The habits of rats and mice are well known. They
inhabit our buildings, gnaw our doors and furniture, de-
stroy our provisions, kill poultry, and aid in spreading
disease. They shun the light, living in holes during the
day, run with great agility, and are capable of making
long leaps. Owing to their instinct to go into holes, they
are easily trapped by a funnel-shaped opening leading into
a closed box. Despite the ease of trapping and their
destruction by cats, they maintain themselves by virtue of
a great fecundity, for, if no deaths occur, several hundred
young may, in one year, descend from a single pair.

The food of mice is very varied. They naturally thrive
best on a vegetable diet; oats especially are recommended
for tame mice, and hard-shelled nuts are useful because
the mice keep their teeth sharp by gnawing the shells. If
the teeth are not kept worn off they soon become incon-
veniently long owing to the fact that they grow continu-
ously throughout life, and are not formed, once for all, like
our teeth. In addition to plant materials, rats and mice
eat a certain amount of animal food.

The different races of tame mice illustrate the results
obtained by preserving sports and selecting the best for
breeding purposes. The white mouse, for instance, is an

320

ZOOLOU Y

albino ; that is, an animal without pigment. Albinos oc-
cur among almost all kinds of mammals, but the cause of
them is unknown. So, likewise, the black race of tame
mice is due to an excess of pigment, a sport found now
and then among other mammals. The pure reddish brown
races have probably been produced by selecting the house
mice with little black in the fur. By preserving occasional
sports and by selecting for breeding the purest-colored
individuals, all the different races of our domestic animals
and plants have been established and improved.

Other Rodents. — The mouse belongs to the group Ro-
dentia,1 distinguished from other mammals by the fact that

Fi<;. 21)5. —

itK (><?</, the Georgia gopher. One-half nat. size. After
V. Bailey.

the cutting teeth grow continuously throughout life, a con-
dition associated with the habit of gnawing. This group
is very abundantly represented in North America, more
so, indeed, than in other continents. All our rodents fall
into seven families: (1) the squirrels, gophers (Fig. 295),
prairie dogs, and wood chuck, with long and hairy tail ;
(2 ) the beaver, with broad and scaly tail ; (3) the pouched
gophers, with peculiar cheek pouches opening outside the

1 "From roder f, to gnaw.

THE MOUSE AND ITS ALLIES

321

mouth ; (4) the jumping mice, with greatly elongated
hind legs; (5) the muskrat and the various wood and
field mice, closely related to the genus Mus ; (6) the por-
cupines, with bristles replacing hairs ; (7) the hares, with
long ears and short tails. All of these familiar rodents
are, on the whole, destructive to agriculture. As there
are, however, other interests in life than agriculture, it is to
be hoped that the warfare against our native rodents will
not be too relentlessly pursued. At least one interest-
ing species has been rendered well-nigh extinct by the

FIG. 296. — Ortiithorhynctius atiattnus, the duckbill. After Vogt and Specht.

avarice of fur hunters - - this is the American beaver, an
animal which has developed extraordinary instincts for the
construction of dams and subaquatic passages.

Other Mammals.- The Monotremata1 are the lowest
mammals, and in many ways seem to connect the class
with reptiles or amphibians. The milk glands are in a

s, single, Tprjua, hole or opening ; so called because urinary, geni-
tal, and alimentary canals have a common external opening.

822

ZOOLOGY

low state of development and eggs are laid, as in reptiles
and birds. There are two principal types, - - the " Duck-
bill' (fig. 296), with aquatic habits, and the "Spiny
Ant-eaters' (Echidna, Fig. 297), inhabiting rocky places.
Both types are confined to Australia and neighboring
islands.

The Marsupialia ! have a remarkable distribution over
the earth to-day. All are confined to Australia and adja-

FIG. 297. — Echidna aculeata, the spiny ant-eater. After Vogt and Specht.

cent islands, excepting the family of opossums (Fig. 298),
found only in the Americas. There is thus a great dis-
continuity in the distribution of marsupials. This is
accounted for by the evidence that formerly the whole
world contained marsupials, so that those living to-day are
the separated remnants of that once universal race. The
opossums are most numerous in the tropics, but the Vir-
ginian opossum ranges north to New York.

1 marsupitan, a pouch.

THE MOUSE AND ITS ALLIES

323

The Edentata,1 few of which are entirely without teeth,
include the sloths, hairy ant-eaters, armadillos, scaly ant-
eaters, and aardvarks, or African ant-eaters. The three
first-named families inhabit South America ; the two
latter, Asia and Africa. Here, again, the discontinuity of
the group indicates what fossils prove, that the Edentates

FIG. 298. —

ij* rirgittlana, the North American opossum. After
Vogt and Specht.

have been killed off from the connecting continents. The
sloths have incisor teeth, live in trees, and eat leaves (Fig.
299). The armadillos are protected by strong plates de-
veloped in the skin ; they are chiefly nocturnal and om-
nivorous animals, and burrow rapidly. The other three
families feed on ants and termites, lack complete teeth (ex-
cepting the aardvarks), and are either arboreal or burrowing.

1 e, out ; dens, dent is, tooth.

324

ZOOLOGY

The Cetacea1 have taken to an aquatic life, for it is
certain that their ancestors were land animals. The sea-
cows (manatees2), found in rivers in various parts of the
world, seem8 to show a transition to the marine forms,

FIG. 299. — Choloepus, the unau or two-toed sloth. After Vogt and Specht.

such as the dolphins, the toothed whales (Fig. 300),
and the toothless or whalebone whales. The largest of
these whales - - the Greenland whale - - reaches an ex-
treme length of twenty-two to twenty-four metres, and a

1 cetus, whale. 2 From a native name.

3 The relation to Cetacea is not close.

THE MOUSE AND ITS ALLIES 325

weight of over 100,000 kilogrammes. It is, indeed, the
largest living animal. Although whales in general are
partly adapted to an aquatic life, they still retain the
essential mammalian qualities. They breathe air which
passes to the lungs and is expelled again through the
nostrils, which are placed high up on the head. The
" blowing ' of the whale is the forcible expiration of
moisture-laden air, which becomes visible by condensation,

FIG. 300. — Oca, the killer whale. After True.

just as our own breath does on a cold day. The young
are doubtless born in the water, but the breeding habits
are poorly known. The various Cetacea have diverse
feeding habits. All are predaceous. The toothed whales
feed on larger animals, the whalebone whales on floating
fish, Crustacea, medusae, and squids ; their whalebone is,
indeed, merely a strainer to let the water pass out of the
mouth while the solid masses are retained.

The order Ungulata1 includes a large number of animals,

1 unyula, hoof.

326

ZOOLOGY

almost all of which are closely related. In the true ungu-
lates there are never more than four functional toes ; but
in the subgroup of Subungulata, containing the elephants
and certain small animals allied to the "coney' of
Scripture, there are typically five. Of the true ungulates,
we distinguish the even-toed and the odd-toed, which we
may consider further.

FIG. .'301. — Stone's Alaskan black sheep. Photo, of a group HI the Field

Columbian Museum.

The Even-toed Ungulates include the hippopotamus and
other pigs and the peccaries, the camels and llamas, the
deer, the giraffes, and the antelopes, sheep (Fig. 301), and
oxen. Excepting the pigs, most of these feed exclusively
on plants. The giraffes and antelopes are characteristic of
Africa; but the "mountain goat" of our highest ranges is

THE MOUSE AND ITS ALLIES 3*27

a true antelope, as is also the chamois of Europe. The
prong-horn of our Southwestern plains is remarkable in
having hollow horns like the antelopes, which are, how-
ever, shed like those of the deer.

The Odd-toed Ungulates include the horses, tapirs, and
rhinoceroses. The horses are remarkable in that they stand
upon the toe-nail of the middle digit — all the other digits
being rudimentary or absent. While fossil remains of
horses are found in all continents, the living species have
come from Asia and Africa. The African species are
striped (zebras). The tapirs are found living to-day
only in South America and southeastern Asia. They
frequent the depths of forests near watercourses and
feed on leaves and shoots of shrubbery. The rhinoceroses
of Africa, of India, of Java, and of the Malay Archipelago
are quite distinct. All are large, stupid, and ferocious
when attacked, feed on herbage, and wallow in pools.

The elephants are distinguished by their long trunks,
great incisors (tusks), and huge, complex grinding teeth.
The Indian and African types are quite distinct. Ele-
phants are intelligent, tractable, and capable of doing
much work for man. Their diet is vegetable, consisting
especially of the leaves and young branches of forest
trees, which they gather with their proboscis.

The Insectivora1 are small mammals and chiefly terres-
trial. One of our common families includes species of
moles which burrow in the ground, have small eyes and
broad, shovel-shaped fore feet, used for digging their bur-
rows. They feed chiefly on earthworms. The other
common family is that of the shrews, which are mouse-like,
live chiefly on the surface and in the woods, and feed on
insects and small crustaceans.

1 insectum, an insect ; vomre, to devour.

328

ZOOLOGY

The Carnivora1 include both land and marine forms.
To the first group (Fig. 302) belong the cats (including
tigers, lions, leopards, lynx, etc.) ; the civet-cats, mongoose,

FIG. 302. — Felis jubata, the Cheetah or hunting leopard. Photo, of a group,

iu the Field Columbian Museum.

etc. ; the hyenas ; the dogs (including jackals, wolves, and
foxes) ; the bears ; the raccoons; and the great/?/ r-bearers, —
martens, minks, weasels, badgers and otters, and skunks.

FIG. 303. — Phoca vitulina, the harbor seal. From Parker and Haswell,

" Manual of Zoology."

1 caro, carnis, flesh ; vorare, to devour.

THE MOUSE AND ITS ALLIES 329

Marine Carnivora comprise the seals (Fig. 303), walruses,
and sea-lions ; the more valuable of which are disappearing
as a result of man's lack of foresight. Altogether, the Car-
nivora comprise the most agile, the most intelligent, the
most dreadful, and some of the commercially most im-
portant of fellow-animals.

The Cheiroptera,1 or bats (Fig. 304), are extraordinarily
modified mammals, which, like the birds, seem to have

FIG. 301. — Syuotus, an insectivorous bat. After Vogt and Specht.

penetrated into the air to prey on the flying insects. Not
all bats are insectivorous, however, for certain Old World
bats feed on fruits. Our commonest species are the little
brown bats (with a nearly fuiiess wing), and the red bat
(with patches of fur on the wing membrane).

The Primates2 are of interest because we ourselves are
placed in this category together with certain other animals
that have attained a less lofty station. The lowest Pri-
mates are the lemurs, found chiefly in Madagascar. These
have an arboreal habit, and feed on fruits, leaves, and

, hand ; irTepov, wing. 2 primus, the first.

330

ZOOLOGY

small birds and insects. Next higher come the American
marmosets, the howling monkeys, and the flat-nosed, pre-
hensile-tailed American apes ; still higher are the small-
nosed, nonprehensile-tailed apes, including the baboons,

FIG. 305. — Simla satyrus, the orang-utan, in breadfruit tree. From a
photograph of a group, in the Field Columbian Museum.

mandrills, and macaques. Finally, come the tailless, man-
like apes, found exclusively in the Old World- -the gib-
bons, orangs (Fig. 305), chimpanzee, and the gorilla.
The two latter are nearest to man, but one cannot say
one is the nearer. For, while the chimpanzee approaches

THE MOUSE AND ITS ALLIES

331

man more closely in facial appearance and in intelligence,
the gorilla is more man-like in the size and complexity of
the brain and in its habit of walking on the ground. There
is no reason to doubt that man's species came off from the
anthropoid apes ; the recent discovery, in Java, of a fossil
form (Pithecanthropus erectus) intermediate between man
and the man-like apes, is a strong additional piece of evi-
dence. This differentiation of man's species probably
began in late tertiary times.

<i\.

APPENDIX TO CHAPTEPv XX

KEY TO THE ORDERS OF MAMMALIA

Oviparous; no mam nine developed

Young born prematurely ; reared in marsupium .

Viviparous ; no marsupium.

1>\. Teeth without enamel .

b-2- Teeth with enamel.

c\. Hind limbs absent.

</i. Elbow and wrist move on each other
rf2- Fore limbs not flexible
Hind limbs present.

(?i. Digits end in hoofs or hoof-like nails
Digits end in claws.
c\. Without hands or membranes

between digits,
/i. Canines absent .
fz- Canines large
/3. Canines small .
Without hands ; membrane be-
tween digits ....
With hands

Monotrevnata

c2.

Edentata.

Sire nia
Ce.tacea

Ungulata

d-2.

Rodentia

<?2.

Cheiroptera
Primates

CHAPTER XXI

THE DEVELOPMENT OF THE FROG'S EGG

ALL living matter has the capacity of increasing itself
under proper conditions to an almost unlimited extent,
the food which animals devour being the material out of
which the new living substance is made. This living sub-
stance exists in isolated particles, or masses, which we call
individual animals or plants. The animal or plant has
also at any stage a definite form which is not exactly alike
in any two individuals, but is roughly alike inside the
"species." Now the number of individuals of any species
tends constantly to diminish through death. It is actually
maintained by reproduction. Reproduction always takes
place in one way ; namely, by a piece of the parent
individual being cut off to form a new individual. This
piece may be at first almost shapeless or approximately
spherical. But as it grows larger it assumes more and
more the form and complex structure of the adult. This
process of growing into the adult form is development.
In most of the more familiar cases development begins
with an approximately spherical egg.

In the case of the frog, the egg is between one and two
millimetres in diameter. The eggs, which are numerous,
are laid in a common jelly and during development float
near the surface of the water in which they are laid.

332

THE DEVELOPMENT OF THE FROG'S EGG 333

Effect of Heat and Light on Development. — Eggs devel-
oping in normal environments in nature arrive at nearly
the same end-result even when the environments are not

J848
MARCH 1lTfi

20J.H
230
25TH

27TH

28TH
31ST

APRIL 4TH
6TH

10TM
MAY 22D

AUG. 18T.H

28TH

OCT. 3 1ST

60°FAHR.

MEAN TEMPERATURE

56°FAHR.

53°FAHR.

51°FAHR..

FIG. J306. — A chart showing the correlation between the stage of development
of the frog on successive days and the temperature at which it has de-
veloped. From Higgenhottom.

identical. We gain, in consequence, an impression that
development proceeds unaffected by any changes in the
outside world. But this is not true. For one thing, the

334 ZOOLOGY

rate at which the development of frogs' eggs proceeds de-
pends closely upon the temperature of the water. They
develop most rapidly at about 30-32° C. If the tempera-
ture is elevated above this point, the rate of development
is retarded, and finally ceases at about 40° C. So, likewise,
as the temperature is lowered, the development is retarded,
until at the temperature of freezing water it ceases
(Fig. 306). If the temperature is too high, development
may be abnormal, so that a monstrosity is produced.

Light has a less striking effect on the development of
the frog. If light is excluded from the developing eggs,
they will develop more slowly. The acceleration of
development by rather high temperature and by daylight
is probably due to a chemical effect of these agents. It
indicates that development is a complex chemical process.

Healing and Regeneration. — If the egg of a frog be
pricked slightly, there will be a loss of substance and the
resulting embryo will be at first abnormal. Later, how-
ever, this abnormality will become smoothed over by
appropriate development. So, also, if the tail of the
developing larva is mutilated, the AVOUIH! will heal and the
missing parts will be re-formed. This capacity of the living
organism to restore the normal form after mutilation is
seen also in man. For if some of the skin be cut away, or
even if parts of internal organs are removed, the wounds
will not merely heal, but the lost part will regenerate.
The remarkable thing is that in regeneration almost
exactly that is produced which was lost. Both regenera-
tion and healing in the adult are a survival of the same
capacity for development which we see in the egg.

Postembryonic Development of the Frog.- -After reach-
ing a certain stage of development the embryo frog, called

THE DEVELOPMENT OF THE FROG'S EGG 335

tadpole, begins to develop legs. The hind legs first
appear, afterward the fore legs sprout out, and finally
the tail begins to wither away, until the form of the four-
legged tailless frog (anuran) is fully developed. In the
leopard frog, as in the toad, this change of form (jnetamor-
phosis) is completed during the first summer, but in case
of the bullfrog and green frog the tadpole passes through
the winter in the immature state, and does not complete
its metamorphosis until the second summer. Conse-
quently, it is not uncommon to find quantities of large
tadpoles in ponds at the time the ice breaks up in the
spring.

Since Amblystoma and Necturus do not lose their tails,
the metamorphosis which they undergo is less profound
than that of the frog. In Amblystoma, as stated in Chap-
ter XVII., the gills and the fin on the tail of the tadpole
are lost in the metamorphosis. Necturus, on the con-
trary, retains gills and tail-fin, so that its acquisition of
legs is almost the sole indication of metamorphosis.

General Laws of Development. — Development consists
of an unfolding of potentialities wrapped up in the germ ;
an awakening in orderly succession of processes lying
dormant there. But the causes which control develop-
ment, the causes which determine when this process and
that shall awaken, are still too obscure for us to attempt
to picture them in detail. This much is certain, that the
causes of development from the egg are the same as those
of budding of leaves on a tree, the regeneration of the
parts of a Hydra, or the healing of a cut in the skin. In
the case of most of the higher plants and animals, the ripe
egg will not develop until it is " fertilized," that is, until a
germ from another individual has fused with the ripe egg.

336 ZOOLOGY

But the ripe egg of many of the lower plants and animals
requires no fertilization for development, and the meaning
of the fertilization process is quite obscure.

The developing eggs of all the higher animals pass
through much the same sort of early stages. The egg
" cleaves ' into a number of cleavage spheres, each of
which is destined to give rise to a particular part of the
organism. By repeated division, a mass of small cells,
constituting the morula stage, is formed. Usually a
cavity arises in the middle of the morula, and into this
some of the surface cells are pushed to form an internal
sac - - the food canal. This is necessarily an early step, as
all food is taken into the interior of the body. The pro-
cess by which external cells are pushed in is known as
gastrulation. Very early the body is seen to be composed
mostly of layers, or membranes and cavities. It is by the
folding and union and breaking through of these mem-
branes that most of the organs of the adult arise. Devel-
opment of the individual is, on the whole, accompanied
by increase in complexity. The evolution of animals in
the animal kingdom is likewise, on the whole, accompanied
by increase in complexity of organization. Thus both the
embryonic development of the individual and the evolu-
tion of the species proceed from simple to complex, and
since they start from about the same point and reach the
same goal, we are not surprised to find that the individual
development of any species often goes through stages
markedly like the stages in the evolution of the species.
The parallelism of development and evolution was early
noticed, and is often called " von Baer's law," after a
naturalist who lived in the middle of the nineteenth cen-
tury and very clearly formulated this parallelism.

APPENDIX I

NOTE.— This outline is reprinted, with some changes suggested by patting it
in practice, and ivith the addition of Exercise XX., from an " Outline of
Requirements in Zoology intended for use in preparing students for the
Lawrence Scientific School," Harvard University, published in 1898 by the
University. The outline was the product of the Zoological Department
of the University, iv ax planned in detail by one of the 2) resent writers, and
is republished by permission of the University. The outline agrees also
with the requirements for admission in Zoology to the University of Chi-
cago, and ivith the recommendations of the" sub-committee of ten on
Zoology appointed by the National Educational Association. Its general
plan has been followed in various schools over the country. The favor-
able reception of the outline justifies its reproduction here.

OUTLINE OF LABORATORY WORK IN ZOOLOGY

INTRODUCTION1

Time. — This outline of work in Zoology is designed for use in
schools that can give to the subject five periods per week for half
a year, including time spent in laboratory work, written exercises,
and oral instruction by the teacher. It is likewise available for
schools that follow the recommendation of the Committee of Ten
of the National Educational Association and give to the subject
three periods per week throughout the year.

Amount of ivork. — The outline includes much more work than
any school ought to attempt in the time indicated above. It is
believed that if about ten of the twenty-one exercises are thoroughly
done, the time will be well filled. The number of exercises is made
large to admit of a selection to suit the diverse conditions of schools.
Thus, those schools which are not equipped with compound micro-

1 Certain verbal changes have been made in reprinting the Introduction, a
few sentences ha\ve been omitted, and there are certain additions, which are
enclosed in brackets.

z 337

338 ZOOLOGY

scopes will, nevertheless, be able to select from nineteen exercises,
while those which in addition are unable to make use of living
marine animals will still have a choice from seventeen exercises. A
thorough study of a few types, rather than a more superficial study
of many, should be aimed at.

General aim. - - It is the general aim of these exercises to interest
as well as to train the pupil ; indeed, it is believed that the awakening
of interest is the best preliminary and accompaniment to a useful
mental training. Since young persons are especially interested in
living animals, observations and non-injurious experiments upon the
normal reactions and the methods of locomotion of animals are
required in nearly every exercise. While the study of active animals
will entail much additional labor on the part of the teacher, and
some additional expense, it is believed that the results will justify
the cost. In order to carry out the aim of these exercises, it is desir-
able that the student find answers to his questions, as far as practi-
cable, from the object before him, rather than from the teacher or
from books. Questions involving comparisons between the types have
been omitted, not because they are regarded as unimportant, but
because they would necessarily vary according to the particular
types selected and the order in which these types are studied. How-
ever, the necessity which compels their omission is the less to be
regretted, since it leaves the teacher free to exercise his owrn judg-
ment and experience in this matter, but he should not fail to supply
such questions.

Sequence of exercises. — The sequence of exercises must depend
largely upon availability of material ; but it is desirable that closely
related types should be studied in immediate succession to facilitate
comparisons. The following are suggested for courses occupying
different periods in the year : —

LABORATORY WORK

339

Whole Year.

First Half.

Second Half.

I. Grasshopper

VII. Crayfish

II. Butterfly

VIII. Daphnia

III. Beetle

XIV. Hydra

IV. Fly

XV. Paramecium

XIII. Starfish

XL Slug

X. Nereis

XII. Anodonta or

IX. Earthworm

Unio

VI. Spider

VI. Spicier

IX. Earthworm

V. Lithobius

X. Nereis

VII. Crayfish

XVII. Newt

VI. Spider

VIII. Daphnia

XVIII. Lizard

V. Lithobius

XI. Slug

XVI. Smelt

IV. Fly

XII. AnodontaorUnio

XIX. Sparrow

III. Beetle

XIV. Hydra

XX. Mouse

XVII. Newt

XV. Paramecium

XL Slug

XXL Frog's Egg

XXI. Frog's Egg

XII. Anodonta or

XVI. Smelt

Unio

XVIII. Lizard

XVII. Newt

VII. Crayfish

XIX. Sparrow

XVIII. Lizard

VIII. Daphnia

XX. Mouse

XIX. Sparrow

XIV. Hydra

XIII. Starfish

XX. Mouse

XV. Paramecium

II. Butterfly

Equipment. — A well-lighted laboratory provided with tables is
almost necessary, but the teacher may find it possible, with much
additional work and less satisfactory results, to conduct the exercises
at the students' ordinary desks. The apparatus required will depend
upon the exercises selected. In any case there will be needed at
least one large aquarium. For this purpose battery jars twelve inches
in diameter will be found serviceable. For keeping living insects,
cages made of wire netting, placed over food plants growing in broad
" seed-pans," are recommended. An ingenious teacher will be able
to make many cheap substitutions for some of the apparatus
specified. Thus in place of " Stencler dishes " tumblers may be
used.

Laboratory book's. — The drawings should be made on a good

340 ZOOLOGY

quality of drawing paper. Tablets made of un glazed drawing paper,
about eight inches by ten inches, are recommended.1 "Where loose
sheets are employed they must be bound at the end of the course.
The drawings should be made with pencil of a hardness (HIIH or
HHHH) appropriate to the paper, and kept well sharpened. The
use of colored crayons or water colors is to be discouraged. Few
pupils can employ shading to advantage. Students are to be in-
structed that pencil lines should represent boundaries of structures.
The names of the parts represented must be designated and should
be the simplest applicable.

Records of experiments, answers to " Questions on External
Anatomy," comparisons drawn, and other written exercises should
be brief. They should not be made upon the same sheets with the
drawings, but either in a separate note-book or on sheets of the same
size as the drawing sheets and eventually bound up with them.2

Observations on the living animal. — The experiments upon living
animals, especially such as involve reactions to stimuli, should be
repeated two or three times, since the first response of the animal
may be abnormal or irregular.

Topics for further study. — Under this heading there are given in
each exercise suggestions for oral instruction by the teacher, or for
reading and recitation on the part of the pupil, in connection with
the laboratory work on the type. The teacher will find aid from the
larger text-books, encyclopaedias, systematic works, and compendia of
Natural History. [The accompanying text-book is fitted especially to
these Topics.]

Excursions. — The teacher is urged to undertake, so far as prac-
ticable, excursions with his pupils to localities where the organisms
studied in the laboratory and their allies can be seen in their natural
environment. The student should be encouraged to collect and study
insects, mollusks, and other invertebrates, and to make observations
on their habits. Directions for collecting various kinds of animals

1 [Boyer's Science Tablets, made by the Central School Supply Company,
Chicago, are convenient.]

2 The Harvard requirement says: The laboratory work should be done
under the immediate supervision of the teacher, so that he can certify that the
drawings and written work are the pupil's own.

LABORATORY WORK 341

are given in the Bulletin of the U. S. National Museum, No. 39.
Parts A to M, 1891-1899 are already published.

Material. - - The teacher should know before beginning the course
which of the types he can obtain alive in his locality, and where and
in what months they can most readily be found. He should know
these things not only about the ten types selected but also about
others, as certain types may prove to be unobtainable when wanted.
He must give due attention to the difficulty of procuring living
material during cold weather. Pupils should be encouraged, where
practicable, to aid in procuring material for class work ; the excur-
sions recommended may be utilized to some extent for this purpose.

Correspondence from teachers who, as a result of their experiences
in using this outline, have any suggestions to offer which may be
incorporated in a future revision of it, is solicited.

[Dealers in animals for class work. — Mr. George K. Cherrie,
Brooklyn Institute Museum, Eastern Parkway and Washington
Avenue, Brooklyn, N. Y., will undertake, after September 1, 1900, to
supply schools with the animal material illustrative of most of the
families referred to in the text, and will supply schools and colleges
with preserved animals in quantity for class use.

Dealers in live animals are : —

Mr. C. J. Maynard, 447 Crafts Street, West Newton, Mass.

Mr. F. G. Hillman, New Bedford, Mass.

Aquarium Supply Co., Delair, N. J.

Messrs. C. E. Blake, 1486 E. 69th Street, Chicago, 111. (can furnish
some of the material alive).

In addition to the foregoing, preserved material will be supplied by : —

The Marine Biological Laboratory, Woods Holl, Mass.

Messrs. II. H. & C. S. Brimley, Raleigh, N. C. (also some living
material).

Mr. F. W. Wamsley, Acad. Nat. Sci., Philadelphia.

Most of these dealers will furnish catalogues of material on
application.]

342 ZOOLOGY

EXERCISES
I. GRASSHOPPER (Caloptenus femur-rubrum}

Caloptenus (which may be replaced by any other member of the
Acrididae or by a cricket) can be obtained abundantly in the autumn.

DRAWINGS

1. Entire animal, left side, wings in place, x 2.

2. Front view of head, x 4.

3. Posterior view of antenna and first and third legs of right side
drawn, for comparison, one below the other, x 3.

4. Upper surface of right wings. Draw a vertical line representing
the axis of the body, mark the anterior (yl) and posterior (P) ends of
the line, and draw the wings one behind the other to the right of this
line, x 3.

5. Lateral view of trunk (left side), with legs and wings removed,
x 3.

6. Mouth-parts, arrange in a column as in No. 4. x 5.

7. Compound eye (hand lens), x 10.

QUESTIONS ON EXTERNAL ANATOMY

1. Is the number of trunk segments constant? (Count segments of
three or more individuals.)

2. Is the number of segments in the leg constant in the correspond-
ing legs of three individuals; in all the legs of the same individual?

3. Describe in not over one hundred words the difference between
the oldest and the youngest individual you have, in respect to («) size
of trunk ; (I) size of wings ; and (c) other characters.

OBSERVATIONS ox THE LIVING ANIMAL

1. Note the respiratory movements of the abdomen. Count the
number per minute. Does the number vary with the individual V
Does it vary with external conditions such as temperature and stimu-
lation ?

2. Holding the grasshopper in the right hand, with the left put the
tip of a blade of green grass to the mouth. Note the movements.

LABORATORY WORK, II 343

How does the grasshopper react to different substances on the end of
the grass blade ?

3. Place the grasshopper under a bell-glass and note and record the
position of the legs in successive phases of walking.

TOPICS FOR FURTHER STUDY

1. Habitat and food of the grasshopper. 2. Distribution of the
species studied. 3. Development (general and external). 4. Allies
of the grasshopper: cricket, green locusts, walking-sticks, Mantis,
cockroaches, earwigs, dragon-flies, ephemerids, termites, the Neurop-
tera, Hemiptera, and Homoptera.

II. BUTTERFLY

Any one of various species whose larvae can be obtained alive near
the end of September may be employed. The cabbage butterfly
(Pieris), the milkweed butterfly (Danais),or the swallow-tail butterfly
(Papilio) will meet these conditions.

DRAWINGS

1. Imago : Dorsal view, wings expanded, x 1 or 2.

2. Imago : Left side, wings closed. (The bodies in 1 and 2 are to
be drawn parallel to each other.) x 1 or 2.

3. Imago : Front of head, x 10.

4. Pupa : Left side.

5. Full-grown larva : Dorsal view.

6. Full-grown larva : Left side.

QUESTIONS ON EXTERNAL ANATOMY

1. How many segments behind the head in (</) the imago? (5) the
larva? (c) the pupa?

2. What external organs of the imago can be identified in the

o o

pupa ?

3. Which feet of the larva correspond to those of the imago ?

OBSERVATIONS ON THE LIVING LARVA

Each student (or group of students) should be provided with a
glass vessel covered with netting and containing food leaves for keep-
ing the larva during pupation.

344 ZOOLOGY

1. How is locomotion effected? Illustrate by diagrams.

2. How does the larva feed? Observe and record the movements
of the month-parts and of the head during feeding. Draw the outline
of a partly eaten leaf.

3. (This obsercafion must extend through several days.} Make and
record observations upon the act of pupation.

TOPICS FOR FURTHER STUDY

1. The habits and food of butterflies. 2. The number of broods of
butterflies during a single season and seasonal dimorphism. 3. Pro-
tective resemblance and mimicry. 4. The larger divisions and com-
moner native forms of Lepidoptera. (Examples of Lepidoptera
illustrating the commoner native types should be shown and students
encouraged to collect and classify them.) 5. The Hymenoptera :
their structure, classification, and habits.

III. BEETLE

The May-beetle and the potato-beetle are recommended for studies
from alcoholic specimens. If these are not available for the " Obser-
vations on the Living Animal," any other slow-creeping species
may be employed.

DRAWINGS

(From alcoholic specimens}

1. Dorsal view, naming parts, x 8.

2. Remove the antenna, mandible, maxillae, and legs of right side.
Draw posterior view of each part. Use lens, x 15.

3. Remove the wing case and membranous wing from left side.
Draw wing (a) folded, (/;) unfolded, indicating position of creases.
Draw imaginary cross-section of the folded wing.

4. Draw beetle from left side, indicating position of removed
wings, x 8.

5. (Optional.} Draw larva from left side, x 8.

QUESTIONS ON EXTERNAL ANATOMY

1. How many segments has the beetle behind the head?

2. (Optional.} How many segments has the larva?

LABORATORY WORK, IV 345

3. From which segments do the wings arise? The legs?

4. Of how many segments is each foot composed ?

OBSERVATIONS ON THE LIVING ANIMAL

1. Place a beetle upon a piece of white paper; observe the order of
movement of the legs in locomotion, and record by some graphic
method.1 Analyze the movement of a leg of each pair; how does
it help the animal to move? Compare with grasshopper.

2. Placing a bit of potato leaf (or other green leaf) at the mouth of
the beetle, notice the movements of the mouth-parts in feeding.

3. Observe and record the movements of the feet of the larva in
locomotion.

TOPICS FOR FURTHER STUDY

1. Stages in the development of a beetle. 2. The principal classes of
beetles : illustrate, e.g., runners, divers, short-wings or rove-beetles,
carrion-beetles, wool-beetles, stag-beetles, tumble-bugs, May-beetles,
boring beetles, snappers,4 fireflies, bark-beetles, weevils, buck-bee-
tles, leaf eaters, ladybirds. (Examples of these should be shown and
students encouraged to collect and classify them.) 3. The food of
beetles. 4. Economic importance: (a) injurious beetles — destructive
to vegetation, to wood, to grain, to meat, to fur and cloth, to useful
animals ; (//) useful beetles — advantageous by acting as scavengers,
by killing injurious insects.

IV. HOUSE-FLY OR BLUEBOTTLE FLY (Musca domestica

and ]\I. vomitorid)

To get larvae of the bluebottle fly it is only necessary to expose
flesh, even on a warm winter day, a week or so before the larvae are
needed for class work. The larvae may be fed upon bran, and when
well grown may be prevented from pupating by being kept at a tem-
perature slightly above the freezing-point.

1 An excellent method, proposed by Professor F. E. Lloyd of Teachers'
College, New York, is to have the beetle walk from an anilin ink pad (ordi-
nary stamping pad) to the paper. The ink on the feet will leave a print of
the steps on the paper.

346 ZOOLOGY

DRAWINGS

1. Imago, dorsal view, wings in place, x 10.

2. Left side, showing stigmata ; wings having been removed and
preserved for further study, x 10.

3. Front view of head, with antennae (lens), x 15.

4. Posterior view of first pair of legs, x 15.

5. Dorsal view of wing and balancer of the right side, x 15.

6. Abdomen, ventral aspect, x 10.

7. (Optional.) Egg of fly. x 10.

8. (Optional.) Larva, side view, x 7.

QUESTIONS ON EXTERNAL ANATOMY

1. How many body-segments has the fly behind the head?

2. How many segments in the antenna?

3. How many segments in the leg ? (Compare with grasshopper.)

4. Can you detect any difference between different individuals of
the same species in respect to form of the head and eyes ?

OBSERVATIONS ON THE LIVING ANIMAL

Each student should be provided with the following: (1) a bell-
jar (or any broad glass vessel) containing a fly and covered with a
card; (2) a soup-plate ; (3) vials of various colored, pungent, sweet,
and neutral substances, such as white sugar, vinegar, butter (prefer-
ably rancid), ground gypsum, white sugar reddened with carmine, |%
acetic acid, molasses.

1. Place on the soup-plate at a little distance apart some sugar,
a drop of vinegar, grains of sugar, and a drop of water. Invert the
bell-jar containing a fly, over the soup-plate, and carefully move the
bell-jar until it covers all of the substances. Xote all the movements
of the fly for five minutes --these are the instinctive movements of the
fly in the given situation; note especially its movements with refer-
ence to the substances.

2. Try the same fly with other combinations such as vinegar, mo-
lasses, water.

3. Try a second fly with one of the same combinations of substances.

LABORATORY WORK, V 347

QUESTIONS

By what substances are the flies most attracted? What is the par-
ticular quality which seems to attract? What sense (sight, smell, or
other) seems to have most influence?

TOPICS FOR FURTHER STUDY

1. The habitat and food of the fly. 2. Development. 3. Respira-
tion. 4. The parasites of the fly. 5. Other Diptera : Glossina
(tsetse-fly), bot-flies, Syrphus, horse-fly, black-fly, crane-flies, gall
gnats, gnats, mosquitoes, sheep-ticks or lice-flies, fleas, and jiggers.
6. The economic importance of Diptera as parasites on animals and
plants, as gall producers, as destroyers of grain, as distributers of
disease, and as scavengers.

V. L1THOBIUS

This myriapod may be obtained under woodpiles, or damp leaves
in woods, even in late autumn or during mild days in winter.

DRAWINGS

1. Dorsal view, x 5.

2. Head, under side, naming principal parts, e.g. antennae, jaws,
first trunk appendages, etc. x 15.

3. Head, upper side. x 15.

4. Two consecutive segments seen from left side, showing legs and
stigma, x 10.

QUESTIONS ON EXTERNAL ANATOMY

1. How many segments in the body? Is the number constant?
(Examine two or three individuals.) Are new segments formed
throughout life ? Compare with earthworm.

2. How many segments in the antenna? Is this number constant?

3. How many segments in the leg?

OBSERVATIONS ox THE LIVING ANIMAL

Each student should be provided with the following: (1) a glass
rod as in No. VI. or toothpicks; (2) vial of cologne; (3) vial of 2%
acetic acid; (4) a soup-plate; (5) a pane of glass large enough to
cover the plate ; (6) forceps to hold Lithobius.

348 ZOOLOGY

1. Study the movement of a single leg and draw three of its phases.
The Lithobius is held in the covered plate.1

2. Make a diagram exhibiting the coordination of leg movement.

3. Touch the antenna with a needle. Response ?

4. Bring a clean glass rod near to an antenna ; then the rod dipped
in cologne ; then cleaned and dipped in acetic acid. Record results
and conclusions.

5. Does Lithobius tend to move from or toward the source of
light?

6. Place on a piece of filter paper, one-half wet and one-half dry,
and note reaction at edge of wet part.

TOPICS FOR FURTHER STUDY

1. Habitat and food of chilopods in general. 2. Distribution of
Lithobius. 3. Allies of Lithobius : Scutigera, Scolopendra, Geophilus,
Polydesmus, Julus ; their habitats.

VI. SPIDER (Argwpe and Theridium}

The large black and yellow garden spider (Argiope) should be
obtained in the fall and preserved in alcohol. The house cobweb
spider (Theridium) can be obtained alive throughout the year in un-
swept corners, especially in cellars. Despite its small size it will
serve for the studies on activities. It may be kept in a 4-inch battery
jar where it will spin its web. Feed upon flies, plant-lice, and other
insects. Other spiders may be substituted for these.

DRAWINGS (of A rgiope)

1. Ventral view showing appendages, opening to air sacs, and spin-
ning glands, x 5.

2. Side view (left), x 5.

3. Front dorsal view of head, showing eyes and jaws (hand lens),
x 10.

OBSERVATIONS ON THE LIVING ANIMAL

Each student should be provided with the following : (1) a glass
rod about 10 cm. long and 2 mm. in diameter, or toothpicks ; (2) a

lrThe movements of the animal may be reduced by adding a little ether, or
by holding the body with a forceps.

LABORATORY WORK, VII 349

vial of essence of heliotrope ; (3) a vial of cologne ; (4) a vial of di-
lute ammonia; (5) a glass-covered box about 8 inches cube.

1. Offer to the spider the end of the glass rod, first clean, then dipped
in essence of heliotrope ; cleaned and dipped in cologne ; in ammonia.
Note and record movements.

2. Place the spider in the box and note for ten minutes its instinc-
tive movements.

3. Leave the spider in the box for a day or two and draw the web ;
in successive stages of formation if possible.

TOPICS FOR FURTHER STUDY

1. Habitat and food of Argiope and Theridium. 2. Distribution
of these spielers. 3. Spinning habits of spiders in general: forms of
webs and nests of the different classes of spiders ; economic impor-
tance of spiders' webs. 4. Biting and poisonous spiders.

VII. CRAYFISH (Cambarus)

Crayfish can be obtained from small streams in most parts of the
United States, except New England. They are also for sale in the
markets of large cities, and are easily transported and kept alive
for days in damp moss. They may eventually be transferred to an
aquarium containing water not more than an inch deep. Feed upon
earthworms or pieces of meat. The crayfish may be replaced by
the lobster.

DRAWINGS

1. View from left side, taking care to preserve accurately the pro-
portions, x 1.5.

2. Ventral view. (Omitting legs.) x 1.5.

3. Draw the posterior aspect of the following appendages of the
right side of animal, without removal from body, x 2.

(a) small antenna. (g) 4th thoracic appendage.

(&) large antenna. (//) 5th thoracic appendage.

(c/) 1st maxilla. (&) 4th abdominal appendage

(e) 2d maxilliped. (swimineret).

(/) 3d maxilliped. (/) last abdominal appendage.

350 ZOOLOGY

4. Draw right side of thorax (carapace previously removed) to
show the number and position of gills, x 2.

5. Draw dorsal aspect of eye-stalk, x 4.

QUESTIONS ON EXTERNAL ANATOMY

1. How many segments in the last thoracic appendage? Xumber
the segments upon your drawing, beginning at the proximal (attached)
end. Number as far as you can the homologous segments upon the
other thoracic appendages drawn.

2. How can you homologize1 with one another the swimmerets, the
legs, and the mouth parts ? Give evidence for each step and indicate
results on the drawings already made.

3. Which is the least differentiated of the series of appendages?2

4. What is the gill formula of the animal in hand?

OBSERVATIONS ON THE LIVING ANIMAL

Each student should be provided with the following: (1) soup-
plate; (2) needle; (3) vial of dilute ammonia; (4) vial of 5% acetic
acid ; (5) vial of carmine.

1. Hold a living crayfish in a soup-plate of water so that the free
edge of its carapace is near the surface. Put a few drops of the carmine
into the water in front of the thorax ; behind the thorax ; between
the legs. Draw a diagram showing the currents. What is the use of
these currents, and by what mechanism are they produced?

2. Hold the living crayfish so that its head and anterior half only
of thorax are submerged ; observe what takes place at hinder edge of
carapace. Hold the crayfish so that abdomen and posterior half only
of carapace are submerged ; what takes place at anterior edge of cara-
pace ? Interpretation ?

3. Determine the function of each pair of legs used in locomotion
and the correlation in their movements.

1 The idea of homology should be made clear. The pupil should indicate the
protopodite (/>), exopodite (ex), and endopodite (en) upon all the drawings of
appendages.

2 The teacher should make use of the crayfish to explain the principle that
different organs have a different degree of specialization or " differentiation."
This will lead to the topic of Division of Labor, as indicated below.

LABORATORY WORK, VIII 351

4. To the tip of one of the large antennre and to the small antennae
apply (a) the point of a needle; (J>) the vapor of ammonia; (c) a
drop of water; (//) a drop of 5% acetic acid. Tests («) and (/;) should
be performed upon the antenna of one side and («), (e), and (//) upon
that of the other. Record the results. What inferences do you draw ?

5. Wave the hand over the crayfish. Does it react ? If possible
flash a light at its head. Can the crayfish see? Cover the eye-stalks
with wax. Does it still react to a movement of the hand?

TOPICS FOR FURTHER STUDY

1. The habitat and food of the crayfish. 2. The geographical dis-
tribution of crayfishes. 3. Other stalk-eyed Crustacea (long and short
tailed) ; lobsters, shrimps, hermit-crabs, spider-crabs, edible crabs.
4. Economic importance of stalk-eyed Crustacea. 5. The breeding
habits and general development of crayfish and lobster. 6. The
capacity for regeneration in the higher Crustacea and the occurrence
of monstrosities. 7. Division of labor in the appendages of the cray-
fish.

VIII. DAPHNIA

Daphnia may be obtained from pools at almost any time of the year
except midwinter. They may be reared in large numbers in aquaria
properly stocked with decaying plants, upon which they feed. Select
for class work the largest individuals (females), which may attain a

length of 2 mm.

DRAWING

Place a living animal on a slide under a cover-glass, and with the
aid of the simple microscope draw a side view, x 20.

OBSERVATIONS ON THE LIVING ANIMAL

Each student should be provided with the following : (1) Stender
dish ; (2) pipette ; (3) watch-glass containing Daphnias ; (4) three
pieces of glass tubing 20 cm. long and 4 mm. bore, with two corks
to fit.

1. Place a Daphnia in the straight glass tube (6) filled with clear
water and corked at both ends. (Exclude air-bubbles in corking.)
Place parallel to the rays from the source of light (preferably lamp

352 ZOOLOGY

light) and cut off side lights. Observe and record movements or lack
of movements.

2. Place a Daphnia in a tube containing a single wad of algse;
place another Daphnia in a tube containing a small pebble ; observe
and record behavior with reference to the foreign body.

3. (Optional.) Place an egg-bearing female in a Stender dish con-
taining bits of decaying plant. After seven days count the number of
individuals. Compare with the number in a similar dish kept (by
the teacher) for seven days in a cool place (5° to 10° C.).

TOPICS FOR FURTHER STUDY

1. The habitat and food of Daphnia. 2. Allies of Daphnia: Bran-
chipus, Cyclops, Cypridopsis, barnacles, trilobites. 3. The pupil should
learn to distinguish Daphnia, Cyclops, and the other Entomostraca in
the aquarium by their locomotion.

IX. EARTHWORM (Allololoplwra or Luminous)

Various species may be used. During the winter time, when the
ground is frozen, earthworms are best sought under compost heaps;
or they may be kept in laboratory in flower-pots containing rich, moist
vegetable mould and covered by a glass plate. They may be fed
upon fallen leaves placed in the pots.

DRAWINGS

(From alcoholic specimens)

1. Whole animal, dorsal view, x 2.

2. Head end, 6 or 8 segments, ventral view, x 5.

3. Tail end, 6 or 8 segments, ventral view, x 5.

4. Two adjacent middle segments, showing setse. x 5.

5. Cross-section, showing position of setae, x 5.

QUESTIONS ON EXTERNAL ANATOMY

1. Count the number of segments of two or three individuals.
Are they the same? Inference to be drawn from the result?

2. Where does growth in length take place? Evidence for your
conclusion ?

LABORATORY WORK, X 353

OBSERVATIONS ON THE LIVING ANIMAL.

Each student should be provided with the following : (1) plate cov-
ered with moist filter paper; (2) hand lens; (3-5) vials containing
sugar solution, acetic acid, and beef extract; (G) four new toothpicks ;
(7) pipette.

1. Touch with a toothpick, first the head end, then the tail end of
the worm ; to which contact does it react more strongly ?

2. Place the earthworm near the window. Does it move toward
or from the light ?

3. With the breath blow upon the head end of the worm. Record
results. Are results due to the warmth of the breath or to the
current of air ? To test, send a puff upon the head with a pipette.

4. Bring near to the head end in succession the ends of toothpicks
dipped in water, in sugar solution, in acetic acid, and in beef extract.
How does the worm react to each fluid ?

5. Place the earthworm on a piece of filter paper two-thirds of which
is wet. Reaction of worm at edge of wet part ? How do these reac-
tions of the earthworm accord with its ordinary movements out of
doors ?

6. When the head end is being thrust out forward, in what phase
(contraction or expansion) is the middle of the worm? The tail
end? In what direction does the contraction wave pass?

TOPICS FOR FURTHER STUDY

1. Habitat and food of the earthworm. 2. Economic importance
of earthworms. 3. Allies of the earthworm : Nais, Dero, Tubifex,
the leeches, the Gephyrea, the Bryozoa.

X. NEREIS

Nereis can be obtained at the sea-shore by digging in mud flats
between tide lines. It can be transported in damp sand or seaweed,
and will remain alive for several davs in a shallow vessel filled with

sea-water and kept in a cool place.

DRAWINGS

(From alcoholic specimens)
1. Whole animal, dorsal view. Natural size.
2 A

54 ZOOLOGY

2. Head end, dorsal view, x 5.

3. Tail end, dorsal view, x 5.

4. Two adjacent middle segments, dorsal view, x 5.

5. Posterior aspect of a single middle segment, showing parapodia.
x 8.

QUESTIONS ON EXTERNAL ANATOMY

1. Which segments are most specialized?

2. Does the number of segments increase during life? Compare
several worms.

3. Which segments are last formed in the individual's development ?

OBSERVATIONS ON THE LIVING ANIMAL

(TW persons may work together upon a single Nereis.') Each stu-
dent should be provided with the following: (1) hand lens; (2)
needle ; (3, 4) vials containing 5% sugar solution and 5% acetic acid ;
(5) pipette.

1. How is locomotion accomplished by Nereis? Analyze the move-
ments involved in locomotion. Relation of phases of writhe to
phases of stroke and recovery of fin. Form of fin at various phases
of its movement. Indicate by diagrams the relations which you
discover.

2. Touch the head with a needle ; what movements ? The tail ;
what movements? What faculty in Nereis is indicated by the
changes of movement after contact ?

3. Drop quietly, by means of a pipette, sea-water upon the head end
and the middle of Nereis; repeat with acetic acid; with sugar solu-
tion. What difference in the movements? What faculty in Nereis is
indicated by these differences in movement ?

TOPICS FOR FURTHER STUDY

1. Habitat and food of Nereis. 2. Its distribution. 3. Its allies :
Autolytus, Lepidonotus, Amphitrite, Serpula, etc. 4. The round
worms and flat worms.

XL SLUG (Umax)

Slugs may be found during the winter in greenhouses and during
the spring and autumn in gardens and orchards, under boards and
stones. They may be kept for considerable periods in a box whose

LABORATORY WORK, XI 355

bottom is covered with damp moss ; they may be fed upon fresh
apples, cabbage leaves, etc. Llmax majcimus is to be preferred on
account of its large size.

DRAWINGS
(From tJie living individual)

1. Dorsal view, showing mantle, foot, respiratory opening, head and
tentacles, x 1.5 to 3.

2. View of right side, x 1.5 to 3.

3. Front view, showing tentacles, mouth, and lips of slime-gland,
x 3.

OBSERVATIONS ON THE LIVING ANIMAL

Each student should be provided with a pane of glass, 8 by 10
inches.

1. Place the slug on the glass and study its locomotion from the
under side of the plate. Describe in the note-book what is seen.

2. Place the slug on the glass plate, hold the plate vertical and
parallel to the window, the slug being horizontal and parallel to
one edge of the pane ; shield from lateral lights. Having made in the
note-book an outline to represent the plate, indicate in this the posi-
tion of the slug at the beginning of the experiment and at intervals of
ten seconds for about a minute. Repeat. A piece of planed board is
better than the glass plate, excepting that it cannot be kept so clean.

3. Place the plate horizontal near a window and let the slug be par-
allel to the window. Do not let direct sunlight fall upon it. Plot in
the note-book, as before, the position of the axis of the slug at inter-
vals of ten seconds o Repeat.

4. Note the reaction of the slug to contact on different parts of the
body : tail, head, antenn?e, edge of mantle.

5. Does the slug react to passes of the hand ? To moisture ?

TOPICS FOR FURTHER STUDY

1. The habitat, food, and methods of feeding of the slug. 2. Its
distribution. 3. The economic importance of slugs. 4. The shell of
the slug. 5. Allies of the slug: Helix, Pupa, Limn sea, Physa, Planor-
bis, Littorina, Fulgur, Fissurella, ^Eolis, Chiton, the Nautilus, and
other cephalopods recent and fossil.

356 ZOOLOGY

XII. FRESH-WATER CLAM (Anodonta or Unio}

Venus may be substituted for these ; and Mya is a favorable object
for this study. Anodonta or Unio may be obtained from most
streams and ponds at any time of the year except midwinter. This
exercise will therefore be best taken in the spring or autumn. To
prepare animals for the study of the soft parts, place them in hot
water (60° C.) for a few minutes; the valves will then open so that
the muscles can be cut where they join the shell.

DRAWINGS

1. Exterior of left valve, showing lines of growth, beak, and margin.
Natural size.

2. Interior of right valve ; name some of the more important parts,
such as margin, scar of mantle, scars of adductor muscles, and retrac-
tor of foot, hinge. Natural size.

3. Bit of fractured edge of burnt shell, to show layers, x 5.

4. Remove the left valve from the killed animal and draw the exter-
nal form of the soft parts from the left side, x 2.

5. Laying back the mantle, draw in place gills (showing surface
structure), body, foot, and labial palps; mark anterior, posterior,
dorsal, and ventral surfaces of the body, x 2.

6. Draw an imaginary cross-section made through the middle of the
body.

QUESTIONS TO BE ANSWERED BY INFERENCE FROM STRUCTURE

1. How does the shell grow?

2. How does the animal close its shell ; how open it?

3. How does the animal gain its food ?

OBSERVATIONS ON THE LIVING ANIMAL

Every student should be provided with the following : (1) vial con-
taining finely powdered carmine in water; (2) vial of carmine in 5%
acetic acid; (3) carmine in 5% sulphuric acid ; (4) carmine in sugar
solution ; (5) pipette ; (6) 4-inch battery jar half full of water.

1. Notice in a living individual in the aquarium the movements of
the mantle, especially at the posterior end.

LABORATORY WORK, XIII 357

2. Hold the clam just below the surface of the water and by means
of a pipette place some carmine suspended in water near the poste-
rior end. Notice the results. How are they to be interpreted ?

3. Offer carmine in sugar solution; in acetic acid; in sulphuric
acid. Is there any difference in the results ?

TOPICS FOR FURTHER STUDY

1. Habitat and food of Anodonta (or Unio). 2. Geographical dis-
tribution of fresh-water clams. 3. General development. 4. Allied
animals from fresh water, such as the Unionidae and Cycladidae ; and
from the sea, such as the Myidae, Veneridae, Arcidae, Aviculidae, Pecti-
nidae, and Ostreidae.

XIII. STARFISH (Asterias vulgaris)

Starfishes can be readily got at low tide in rock pools and on piles
and walls at the sea-shore. They may be transported alive consider-
able distances, if packed in wet eel-grass or seaweed. The living
animals may be placed for study in a soup-plate full of sea-water, or
water containing about 2.5% sea salt. Dry preparations, for the study
of the hard parts, may be made as follows : Leave a living starfish in
a shallow dish of warm, fresh water until fully expanded. Next dip
it into boiling water until hardened, and then dry it in the sun or in

a slow oven.

DRAWINGS

(Nos. 1, 2, 4, and 5 from dried specimen, No. 3 from an alcoholic one.)

1. Aboral view. Natural size.

2. Oral surface of arm showing ambulacral groove. Natural size.

3. Cross-section of arm with ambulacral feet, x 4.

4. Ambulacral ossicles, dissected out. x 2.

5. Spines from aboral surface, x 10.

OBSERVATIONS ON THE LIVING ANIMAL

Each student should be provided with a soup-plate full of salt water.

1. Observe the eyes, the ambulacral feet and their sucking disks,
the gills upon the back. Has the starfish strict radial symmetry?

2. Note the method of locomotion by ambulacral feet. With the
aid of a diagram show what takes place in a single foot.

358 ZOOLOGY

3. Invert the starfish ; observe and record the changes undergone in
reassuming the normal position.

TOPICS FOR FURTHER STUDY

1. Habitat of starfish. 2. Food and economic importance. 3. Gen-
eral history of development. 4. Allied forms ; Solaster and other
starfishes, brittle stars, sea-urchins, holothurians, crinoids.

XIV. HYDRA

This exercise requires the use of a lens.

To obtain Hydra it will be necessary to search carefully in fresh-
water pools. Lemna together with sticks and grass should be
collected from the pools and put into an aquarium. The Hydras,
which are attached to these objects, will then usually migrate in the
course of a few days to the light side of the vessel, where they can
be easily found. Hydras can be kept readily throughout the entire
winter in a large glass jar containing Lemna and other plants, and
Entomostraca for food. All the following exercises can be done on
the living animal, and either the brown species (//. fusca) or the
green species (H. viridis) may be employed.

DRAWINGS

(From living individuals')

1. Side view of a single Hydra, not budding, x 10.

2. Side view of a Hydra with buds, x 10.

(Optional, requires compound microscope.) Draw one of the ten-
tacles of Hydra, showing discharged and undischarged nettling
capsules, x 300.

OBSERVATIONS ON THE LIVING ANIMAL

Each student should be provided with the following: (1) 4-inch
battery jar ; (2) 2-inch Stender dish ; (3) vial containing 5 % sugar
solution ; (4) vial containing 5 % acetic acid ; (5) a few Daphnias in
a watch-glass ; (6) pipette ; (7) needle ; (8) watch-glass ; (0) paste-
board box of a slightly larger size than the battery jar and with a
vertical slit half an inch wide along one side.

Place a Hydra in a watch-glass full of water.

LABORATORY WORK, XV 359

1. Touch the tentacles of the Hydra with a needle. What move-
ments?

2. Drop cautiously and at intervals of a few minutes upon the sur-
face of the water over the tentacles of the Hydra a drop of water, of
susrar solution, of acid. What differences in the movements?

3. Bring a Daphnia (previously stranded) on the end of a needle
to the tentacles of the Hydra. Note the result. With another
Hydra, use a bit of plant tissue.

4. (This and the following experiment must extend through several
day*.} Place a Hydra in a watch-glass with a little water, and by
means of the needle and a penknife cut it into two or three pieces.
Let the pieces expand and draw them. By means of a clean pipette
place the pieces in the small Stender dish, in clean water. Draw
the pieces again after twenty-four hours, and after a longer period if
necessary.

5. Place in a 4-inch battery jar full of water containing Lemna and
Entomostraca two or three large, budding, green Hydras. Cover the
jar with the box, placing the slit next to the window. Note at short
intervals for two weeks the position and number of Hydras in the jar.

TOPICS FOR FURTHER STUDY

1. The habitat and food of Hydra. 2. Other fresh-water or brack-
ish-water hydroids (Cordylophora, Limnocodium) and the origin
of fresh-water Hydrozoa. 3. Marine hydroids (Obelia, Sertularia,
etc.) and their jellyfishes. 4. Sea-anemones and corals. 5. Corals
as island builders. 6. Budding and the formation of colonies among
animals. 7. Division of labor in colonies. 8. Regeneration in
polyps.

XV. PARAMECIUM

This exercise requires the use of the compound microscope.

Twro or three weeks before Paramecia are needed, put hay and
decaying leaves in stagnant water and keep in a warm room. When
the water has become foul, Paramecia have probably appeared. To
prevent the Paramecia on the slide from moving too rapidly, it is
advisable to put them in a 2.5 % solution of gelatine in water. Study
first with the low power, then with the high. To bring out the

360 ZOOLOGY

nuclei in the living animal, run a 5% or 10% aqueous solution of
methyl green under the cover-glass by placing the solution at one
edge of the cover-glass and drawing it under by filter paper placed at
the opposite edge. To stain the plasma, a little iodine may be added ;
this will kill, with explosion of trichocysts.

DRAWING
(From observations on several individuals)

Whole animal, showing shape of body, cilia, vestibule, food-
globules, non-contracting vacuoles, contracting vacuoles, nucleus,
trichocysts. x about 200.

OBSERVATIONS ON THE LIVING ANIMAL

Each student should be provided with the following: (1) vial
containing beef extract ; (2) vial containing finely powdered car-
mine in water ; (3) common salt ; (4) pipette ; (5) filter paper.

1. Is the protoplasm in the body of Paramecium quiet or moving?

2. Place Paramecium in a drop of the gelatine solution. Cover
with cover-glass. Run carmine-water under the cover-glass; select a
quiet individual and observe how the carmine grains pass by it.
Indicate by arrows placed outside the periphery of the drawing the
direction of movement of the carmine. What do vou infer concern-

ing the movement of the cilia? Do the grains whirl as much about
a moving individual as about a quiet one? Can you explain? Why
are not all the Paramecia carried off by the current when carmine is
run under the cover-glass ?

3. Place upon a clean glass slide a drop of water containing Para-
mecia. When they are uniformly distributed, put a few grains of
common salt in the centre of the drop. After a few seconds observe
and draw the distribution of the organisms. How is the result to
be interpreted?

4. Place upon the glass slide a drop of water containing Paramecia;
by means of a pipette (drawn to a fine point), add a drop of \ % to
Tao % acetic acid ; after two or three minutes draw the distribution
of the Paramecia. How do reactions to acids and to salts compare ? l

!See H. S. Jennings, American Journal of Physiology, May, 1899, and
American Naturalist, May, 1899.

LABORATOEY WORK, XVI 361

5. Under a moderate power observe the reactions of Paramecium
when it comes to the salt or acid.

TOPICS FOR FURTHER STUDY

1. Plow the Infusoria get into the aquarium. 2. The habitat and
food of Paramecium. 3. Allies of Paramecium : Stentor, Vorti-
cella, Carchesium, Euglena, the Suctoria, Amoeba, the Gregarinidse.
4. Economic importance of Amoeba and the Gregarinidse. 5. Repro-
duction of Paramecium.

XVI. SMELT (Osmerus mordax)

Various other bony fishes may replace the smelt, e.g. brook trout
(Salmo fontinalis), lake herring or white fish (Coregonus), perch
(Perca).

DRAWINGS

1. Whole animal, from left side, fins extended, showing number of
fin rays, position of lateral line, mouth, tongue, teeth, nostrils, anus,
urinary openings, x 1 to "2.

2. Side view of a few trunk segments as seen after removal of
skin.

3. Ventral view of head, gill cover removed, mouth open, probes
passing from mouth through each of the gill slits. Show teeth and
slime-glands, x 2 to 3.

4. Dorsal view of head, showing, when possible, form of brain seen
through brain case, x 2.

5. Cross-section (5 mm. thick) of whole animal in front of anus
and behind dorsal fin. Name organs as instructed by teacher.

6. Lateral view of vertebra, from the section mentioned in 4,
isolated by boiling.

QUESTIONS ON EXTERNAL ANATOMY

1. How many rows of scales are there above the lateral line ; how
many below ?

2. How many segments behind the head? Is this number constant?
(Compare with two other individuals.)

3G2 ZOOLOGY

3. What special fitness in the form of the body to the habits of the
fish?

OBSERVATIONS AND EXPERIMENTS ON THE LIVING ANIMAL

1. Role of fins in locomotion. By means of a cotton string wrapped
around body, bind clown the pectoral fins and replace in water ;
result? Bind ventrals similarly; result? Wrap string around tail
and replace in water ; result? Conclusions?

2. How do the movements of the caudal fin cause the fish to
progress?

TOPICS FOK FURTHER STUDY

1. Habitat and food of the species. 2. Distribution and economic
importance. 3. Allied species : salmon, trout, white fish. 4. Other
groups of fresh-water bony fishes: the darters, perch, sun fish, stickle-
backs, silversides, minnows, pike, shad, suckers, catfish, eels. 5.
Other kinds of fish : Amphioxus, lampreys, sturgeons, spoonbills,
garpike, Amia. 6. The ontogeny of a bony fish. 7. The migrations
of fish. 8. Artificial breeding and fish-hatching stations.

XVII. NEWT (Diemyctylus viridescens)

For this species may be substituted the small spring or brook
salamanders (Desmognathns and Spelerpes), Amblystoma, or even
Necturus. The small size of the brook salamanders makes them
especially useful for external study and preservation in alcohol.

DRAWINGS (of convenient size}

1. Entire animal.

2. View of the left side of head, mouth open.

3. Left fore foot, dorsal surface.

4. Left hind foot, palmar surface.

5. Form of front lateral teeth, x 10.

QUESTIONS ON EXTERNAL ANATOMY

1. Which is the thumb side of hind foot?

2. Are the spots on the body arranged, according to any law ?

3. Are there two movable eyelids?

4. Where is the ear ?

LABORATORY WORK, XV III 363

OBSERVATIONS ON THE LIVING ANIMAL

1. How are the movements of appendages and tail correlated in lo-
comotion («) on land, (6) in water ? Diagrams.

"2. Observe the instincts of the animal when placed in a box of
earth Q damp and J dry) lighted on one side from the window and
strewn with leaves and stones.

TOPICS FOR FURTHER STUDY

1. Habitat and food of the species studied. 2. Distribution of
Amphibia. 3. Allied organisms in the United States: Desmogna-
thus, Plethodon, Amblystoma, Amphinma, Nee turns, Siren ; their
distribution and habitats. 4. Experiments upon changing Axolotl
into Amblystoma. 5. Egg-laying of Urodela and general form-
changes accompanying development.

XVIII. LIZARD (Anolis carolinensis)

This may be replaced by any other species. Where live lizards
cannot be easily obtained, substitute a snake or tortoise and make
appropriate changes in the following outline.

DRAWINGS

1. Entire animal, dorsal view, x 1 to 3.

2. Dorsal view of head, showing scales, especially the parietal scale,
x 3.

3. Left side of head ; mouth open, tongue exposed, x 3.

4. Left fore foot, dorsal aspect, x 3.

5. Left hind foot, palmar aspect, x 3.

6. Outline of front lateral teeth, x 10.

7. Outline of scales on ventral side at base of tail. X 10.

8. Outline of scales on back, x 10.

QUESTIONS ON EXTERNAL ANATOMY

1. Which is the thumb side of the fore foot ? Why? Of the hind
foot? Why?

2. What is the function of the structures on the pads of the toes ?

364 ZOOLOGY

3. Where is the ear-drum?

4. (This may best be studied on the living animal.') Is there a nicti-
tating membrane, as in birds?

OBSERVATIONS ON THE LIVING ANIMAL

Each student should be provided with a set of Bradley's color cards.

1. Which eyelid is more used in winking, the upper or the lower ?

2. Locomotion : Order of movement of legs ; correlation of leg and
tail movement.

3. Change of color : Effect of colored backgrounds (Bradley's
colors1), of warming by holding in the hand, of stroking the back.

TOPICS FOR FURTHER STUDY

1. Habitat, food, and distribution of Anolis. 2. Common lizards of
the region, if any. 3. Other interesting lizards, such as the chameleon,
the blind worm (Anguis), the Gila monster (Heloderma), lizards of
Europe (Lacerta), fossil Reptilia.

XIX. "ENGLISH" SPARROW (Passer domesticus)

This introduced bird can be obtained in most large cities in sufficient
numbers. Recently killed birds are the most favorable for laboratory
work. Subjection to fumes of carbon disulphide is a useful precau-
tion against bird lice.

DRAWINGS

1. Side view (left). Name parts. Natural size.

2. Head and bill, side view, mouth open, showing tongue, x 2.

3. Foot (left), dorsal surface, x 2.

4. Foot (left), palmar surface, x 2.

5. Contour feather (from tail), x 2.

6. Plumage feather, x 3.

7. The egg. x 2.

QUESTIONS ON EXTERNAL ANATOMY

1. Color of: (a) eye ; (/>) bill; (c) feet ; (d) throat; (e) breast;
(/) belly ; (//) crest ; (/*) side of head ; (/) back ; (/,-) wing ; (/) rump ;
(m) tail feathers ?

1 Milton Bradley Company, Springfield, Mass.

LABORATORY WORK, XX 365

2. Number of tail feathers ?

3. Number of primaries ?

4. How many segments in the leg ; in the wing ?

TOPICS FOR FURTHER STUDY

1. The introduction of the ''English" sparrow into America and
similar instances of introduction and spread of exotic species. 2. The
food and habits of the " English "' sparrow in America. 3. The
native sparrows. 4. Other groups of birds : thrushes, bluebirds, tit-
mice, nuthatches, creepers, wrens, warblers, tan age rs, swallows, wax-
wings, vireos, shrikes, larks, orioles, crows, flycatchers ; parrots and
cockatoos; toucans and cuckoos, kingfishers; woodpeckers, humming-
birds, swifts, goatsuckers ; pigeons ; grouse and fowl ; ostriches ;
waders ; swimmers, and divers. 5. The migrations of birds ; migra-
tion data. 6. Flight of birds. 7. The food and economic importance
of birds. 8. The preservation of birds. 9. Fossil birds.

XX. MOUSE (Mm mustelus)

Tame mice may be obtained from bird fanciers in most of our large
cities.1 They can be kept in the laboratory indefinitely. Galvanized
wire cages with doors and galvanized iron bottoms are serviceable.
Supply with cotton, hay, or excelsior for a nest. Keep at an equa-
ble, moderate temperature, and pay great attention to cleanliness.
Feed on oats and bread, with occasional fruit, carrot, and cooked meat.

DRAWINGS

1. Side view (left). Name parts. Natural size.

2. Head, dorsal view, x 1.5.

3. Fore foot (left), dorsal surface, x 2.

4. Fore foot (left), palmar surface, x 2.

5. Hind foot (left), dorsal surface, x 2.

6. Side view of skull, x 3.

7. Upper surface of lower jaw showing teeth, x 3.

8. Incisor tooth (free), x 10.

1 Mr. H. C. Ostendorf, 420 N. Eutaw St., Baltimore, has been found reliable
by the writer, and keeps a stock on hand.

366 ZOOLOGY

OBSERVATIONS ON THE LIVING ANIMAL

Each student, or set of students, should be provided with the
following: (1) a cage of wire netting about 8 inches cube, with a
door on top ; (2) a tin box or small cigar box, closed except for
a f-inch hole and small enough to be put into the cage.

1. Enumerate the kinds of activities of the mouse in the cage.

2. Bring a piece of toasted cheese to one side of cage. Note any
change of movements.

3. Place the small box in the cage. Note the actions of the mouse.
Does he go directly to the hole or does he find it by accident, or
otherwise ?

TOPICS FOR FURTHER STUDY

1. The distribution of mice and rats. 2. The habits of rats and
mice. 3. The food of mice. 4. The races of tame mice. 5. Other
rodents. 6. Other mammals : the monotremes, marsupials, edentates,
Cetacea, Ungulata, Insectivora. Carnivora, Cheiroptera, and Primates.
7. The descent of man.

XXI. DEVELOPMENT OF THE FROG'S EGG

The eggs of toads and even of Urodela may be substituted,
although this outline accords closely with Anura only. Frog-spawn,
may be obtained in April in ponds and marshes as jelly-like masses
containing the eggs. Toad-spawn occurs as threads intertwining
with the grass at the margins of shallow pools. Eggs may be
obtained from animals in captivity by placing breeding males and
females in a large glass aquarium in the laboratory. The eggs should
be studied shortly after being laid and at various later periods.

DRAWINGS

(While it is desirable that these be ma fie from the living ef/r/s, they may
be made from eggs killed in /tot water at 80° C.)

1. A bit of spawn with a few eggs in place, x 2.

2. Isolate eggs, watch and draw various stages till hatching. The
series should include as many of the following stages as possible :
cleavage, inorula, blastopore formation, medullary folds, gill covers,

METHODS OF EXAMINATION 367

gills, newly hatched tadpole, tadpole several days after hatching.
(Optional, a series of tadpoles showing metamorphosis.) x 15 to 20.
(Keep a record of the time — day, hour, minute — when each stage
was drawn.)

EXPERIMENTS

1. Keep some of the same spawn in a refrigerator for ten days,
then draw and compare with the eggs kept at normal temperatures
for the same length of time.

2. At the time of formation of neural folds, free an embryo from
the albumen, and add carmine grains to the (shallow) water. Note
the direction of currents and motion of cilia.

3. Amputate the tail of a newly hatched larva and observe the
result after a week or two.

4. Find the (approximate) specific gravity of a tadpole by placing
one or two in each of the following solutions of gum arabic in water :

Per cent by weight, 33 16.5 11 8.2 3.3 1.65

Specific gravity, 1.11+ 1.06 1.037 1.028 1.011 1.006

The solution in which they tend, when motionless, neither to rise
nor fall is of their specific gravity. Repeat with tadpoles just hatched
and with those one week, two weeks, three weeks, and four weeks
old.1

TOPICS FOR FURTHER STUDY

1. Effect of heat and light upon development. 2. Capacity of
organisms for healing and regeneration. 3. Postembryonic develop-
ment of the frog, Amblystoma, and Necturus. 4. General laws of
development. 5. Development of the chick. (This should be
illustrated by opening several eggs at various stages of development.)

It may interest teachers to have reproduced here the examination
requirements of two universities which are exactly covered by the
preceding outline : —

!See S. R. Williams iu the American Naturalist, February, 1900, p. 98.

368 ZOOLOGY

I. METHOD OF EXAMINATION IN ZOOLOGY FOR ADMISSION

TO THE LAWRENCE SCIENTIFIC SCHOOL, HARVARD
UNIVERSITY.

The candidate is required to pass both a written and a laboratory
examination. The written examination will test the range and thor-
oughness of his knowledge of the subject. The laboratory examina-
tion will test his skill in observation and experimentation, and his
ability to apply names properly to the parts of the organisms studied.

At the time of the written examination the candidate must present
the original note-book containing (with dates) the notes and drawings
he has made in the course of his laboratory work, and bearing the
endorsement of his teacher, certifying that the book is a true record
of the pupil's own observations and experiments. An index of sub-
jects should be appended.

II. METHOD OF EXAMINATION IN GENERAL BIOLOGY (ZOOLOGY

AND BOTANY) FOR ADMISSION TO THE JUNIOR COLLEGES,
THE UNIVERSITY OF CHICAGO.

The candidate applying for admission credit in General Biology
will be required : («) To submit to the examiner a note-book consist-
ing of drawings and descriptions of the animals and plants studied. It
is recommended that studies of at least fifteen principal forms be
undertaken, that these studies be largely such as do not demand the
use of a compound microscope, and that attention be given chiefly to
those organisms that can be studied in a living condition; (!>} to de-
monstrate, in the college laboratory, under the supervision of college
officers, that he possesses some power to observe accurately and intelli-
gently. More stress will be laid on correct observation and on the
careful record thereof, than upon technical terms; (r) to answer in
writing a few general questions about familiar animals and plants,
such as the perch, crayfish, grasshopper, moss, fern, some common
type of flowering plant, etc.

APPENDIX II

A LIST OF BOOKS DEALING CHIEFLY WITH
ECOLOGICAL AND SYSTEMATIC ZOOLOGY OF
AMERICAN ANIMALS.

A. GENERAL SYNOPTIC WORKS

Leunis, J. — Synopsis der Thierkunde. Dritte Auflage von H. Ludwig.
2 Bande. Hannover. 1883-86.

This is the nearest approach to a systematic manual, taking the place
in Zoology which Gray's and Coulter's Manuals do in Botany. It deals
chiefly with European species ; and has not been translated.

Thomson, J. A. — Outlines of Zoology. 3d edition, with 332 illustra-
tions. New York : D. Appleton & Co. 1899. 819 pp.

An excellent condensed compendium ; in which, however, the struc-
tural side predominates.

Riverside [formerly Standard] Natural History, edited by J. S. Kings-
ley. 6 vols. large 8°. Boston and New York : Iloughton, Mifliin
& Co. Price $30.

The most important large compendium written by American authors,
somewhat after the plan of Brehm's Thierleben.

Cambridge Natural History, edited by S. F. Harmer and A. E. Shipley.
New York : The Macmillan Company. 1894.

An English work of surpassing merit ; five volumes have ap'peared
but the work is still far from complete.

Klassenund Ordnungen des Thierreich.es, edited (originally) by Bronn.
Leipzig u. Heidelberg : C. F. Winter.

An extensive and thorough work. Although the whole work is not
yet completed, some of the volumes are out of date. The most recent and
important are the volumes on Protozoa, Porifera, Cu'lenterata, Vermes,
Echiuodermata, Crustacea, Mollusca, Reptilia, and Birds.
2B 369

370 ZOOLOGY

Das Tierreich. Eine Zusammenstellung und Kennzeichnung der re-
zenten Tierfornien. General redncteur : F. E. Schulze. Berlin :
R. Friedlander und Sohu. 1890 —

A systematic account of every known species, with keys for their de-
termination. An ambitions enterprise which will hardly be finished
during one generation.

B. WORKS RELATING TO ANIMALS OF A PARTICULAR

HABITAT

Verrill, A. E. (and S. I. Smith).- -Report upon the Invertebrate Ani-
mals of Vineyard Sound and the adjacent waters, in Report (of
U. S. Fish Commission) on the Condition of the Sea Fisheries of
the South Coast of New England in 1871 and 1872. (1873.) pp.
295-778.

An indispensable accompaniment of the zoologist at the sea-shore;
separate copies can be purchased of dealers in scientific books.

Emerton, J. E. --Life on the Seashore. [For sale by BradJee Whid-
den, Boston.]

C. GENERAL WORKS ON HABITS, ECOLOGY, AND

DISTRIBUTION

Verworn, M. — General Physiology. An outline of the science of Life.

Newr York : The Macmillan Company. 1899. G15 pp. Price

$4.00.
Morgan, C. L. — Animal Life and Intelligence. New York: Edward

Arnold. 1891. 503 pp.
Morgan, C. L. — Habit and Instinct. New York: Edward Arnold.

1896. 351 pp.

The two best books on the topics considered.

Lubbock, J. — On the Senses, Instinct, and Intelligence of Animals, with

special reference to Insects. International Sci. Ser., Vol. LXIV.

New York : D. Appleton & Co. 1888.
Marey, E. J. — Movement. International Sci. Ser., LXXTII. New

York: D. Appleton & Co. 1895.
Poulton, E. B. — The Colors of Animals. The International Scientific

Series, Vol. LXVII. New York: D, Appleton & Co. 1890.

BIBLIOGRAPHY: ANATOMY AND EMBRYOLOGY 371

Semper, K. - - Animal Life as affected by the Natural Conditions of
existence. International Scientific Series, XXX. New York :
D. Appleton & Co. 1881.

Even to-day the best book on Animal Ecology.

Wallace, A. R. - -Tropical Nature. London and New York: Macmil-
lan & Co. 1895.

Wallace, A. R. — Geographical Distribution of Animals. 2 vols. Lon-
don : Macmillan & Co. 1879.

Beddard, F. E. -- Text-book of Zoogeography. Cambridge (Eng.)
Scientific Series. 1895.

D. WORKS DEALING CHIEFLY WITH ANATOMY AND

EMBRYOLOGY

Parker, T. J., and W. A. Haswell. - - Text-book of Zoology. 2 vols.
Many illustrations. New York: The Macmillan Co. 1897.

Parker, T. J., and W. A. Haswell. --Manual of Zoology. Adapted for
use of American Schools and Colleges. 563 pp. 327 figs. New
York : The Macmillan Co. 1900.

Rolleston, G., and W. H. Jackson.- -Forms of Animal Life. 1888.

Lang, A.- -Text-book of Comparative Anatomy. Translated by Ber-
nard. 2 vols. New York : The Macmillan Co. 1896.

Brooks, W. K. — Handbook of Invertebrate Zoology. For laboratories
and seaside work. Boston : S. E. Cassino. 1882. [May be pur-
chased of Bradlee Whidden, Boston.]

Korschelt, E., and K. Heider.- -Text-book of the Embryology of Inver-
tebrates. 3 vols. New York : The Macmillan Co. 1899.

Balfour, F. M. - - A Treatise on Comparative Embryology. In 2 vols.
London: Macmillan & Co. 1880-81.

Although decidedly out of date, yet gives the best general discussion
of the subject.

Hertwig, 0. - Text-book of the Embryology of Man and Mammals.

Translated by E. L. Mark. New York : Macmillan & Co. 1892.
Wilson, E. B. - - The Cell in Development and Inheritance. New York :

The Macmillan Co. 1896.

372 ZOOLOGY

E. PERIODICALS

Besides " Science" and " Nature," both published by The Macmillan
Co., New York, there will be found of especial interest to the zoology
student : —

The American Naturalist. A Monthly Journal devoted to the Natural
Sciences in their widest sense. Published monthly by Ginn &
Co., Boston. Price $4.00 per year.

This journal is publishing keys for the determination of North Amer-
ican Invertebrates.

F. WORKS ON SPECIAL GROUPS
INSECTS IN GENERAL

The Cambridge Natural History. Yols. V and VI. - - Peripatus, by A.
Sedgwick : Myriapods, by F. G. Sinclair ; Insects, Parts I. and II.,
by David Sharp. Macmillan & Co., London and New York.
1895 and 1899.

Deals especially with Ecology.

Comstock, J. H. and A. B. — A Manual for the Study of Insects. Ithaca,
N. Y. : Comstock Publishing Co. 1895. Price $3.75.

The best systematic treatise (with special reference to economic en-
tomology) on Insects of the United States, with keys to families.

Comstock, J. H. --An Introduction to Entomology. Ithaca: Com-
stock Publishing Co. 1888.

Unfinished, but more detailed than the Manual. Treats of Thysanura,
Pseudoneuroptera, Orthoptera, Physopoda, Hemiptera, and Neuroptera
only.

Comstock, J. H. — Insect Life. An Introduction to Nature Study
and a guide for teachers, students, and others interested in out-of-
door life. D. Appleton & Co. New York, 1897. 349 pp. Price
$2.25.

Packard, A. S. --Entomology for Beginners. Henry Holt & Co.,
New York. 1888. Price $1.40.

Packard, A. S.--Half Hours with Insects. Boston: C. E. Lauriat.
1881.

BIBLIOGRAPHY, I 373

Smith, J. B. — Economic Entomology. Philadelphia: J. B. Lippin-
cott & Co. 1896. Price $2.50.

Packard, A. S.-- Fifth Report of the United States Entomological
Commission [U. S. Department of Agriculture], being a revised
and enlarged edition of Bulletin No. 7 on Insects Injurious to
Forest and Shade Trees. Washington : Gov't Printing Office.
1890. 928 pp. 306 text figures and 40 plates.

A valuable aud inexpensive treatise; can usually be obtained of deal-
ers in second-hand books.

Miall, L. C. - - The Natural History of Aquatic Insects. London and
New York: Macmillan & Co. 1895. Price $1.75.

•

Lubbock, John. — On the Origin and Metamorphoses of Insects. Na-
ture Series. London and New York : Macmillan & Co. 1895.

McCook, H. C. — Tenants of an Old Farm. Leaves from the Note-
book of a Naturalist. New York : Fords, Howard & Hulbert.
1885.

Riley, C. V. — An Enumeration of the published synopses, catalogues,
and lists of North American Insects. U. S. Dept. of Agriculture,
Division of Entomology, Bull. No. 19. 1888. 77 pp.

A very valuable bibliography.

Riley, C. V.-- Directions for Collecting and Preserving Insects.
Smithsonian Institution, Washington, D. C., 1892. Price 25 cents.

I. ORTHOPTERA, NEUROPTERA, HEMIPTERA, ETC.

Scudder, S. H. — Guide to the Genera and Classification of the North

American Orthoptera found north of Mexico. Cambridge : E.

W. Wheeler. 1897. 89 pp.
Scudder, S. H. -- Revision of the Orthopteran group Melanopli

(Acridiidse), with special reference to North American forms.

Proceedings U. S. National Museum, XX. pp. 1-421. Plates

1-26. 1897.
Calvert, P. P. -- Catalogue of the Odonata (Dragon-flies) of the

vicinity of Philadelphia, with an introduction to the study of

this group of insects. Trans. American Entomological Society,

Philadelphia. Price $1.00.

374 ZOOLOGY

Hagen, H. — Synopsis of the Neuroptera of North America, with a
list of South American species. Smithsonian Miscellaneous
Collections. Washington, D. C. 1861.

Banks, N.--A Synopsis, Catalogue, and Bibliography of the Neu-
ropteroid Insects of Temperate North America. Trans. Ameri-
can Entomological Society, Philadelphia. [Sec'y Amer. Entom.
Soc. Price -11.00.]

Osborn, H. — Classification of Hemiptera. Entomologica Americana.
Vol. I., pp. 21-27. 1885.

II. LEPIDOPTERA AND HYMENOPTERA

Scudder, S. H. — Brief Guide to the Commoner Butterflies of the
Northern United States and Canada. Henry Holt & Co., New
York. 1893. Price $1.25.

French, G. H.--Tlie Butterflies of the Eastern United States. For
the use of classes in Zoology and private students. Philadelphia :
Lippincott & Co. 1886.

Scudder, S. H. — The Butterflies of the Eastern United States and
Canada, with special reference to New England. 3 vols. Cam-
bridge, Mass. Published by the author. 1889.

Edwards, W. H. — The Butterflies of North America. Boston :
Houghton, Mifflin & Co.

Holland, W. J. - -The Butterfly Book. A popular guide to a knowl-
edge of the butterflies of North America, with 48 plates in color
photography. New York : Doubleday & McC lure Co. 1898.

Knobel, E. — The Day Butterflies and Dusk Flies of New England ;
how to find and know them (1895); also The Night Moths of
New England; how to determine them readily (1895). Boston:
Bradlee Whidden.

Cresson, E. T. — Synopsis of the Families and Genera of the Hytne-
noptera, North of Mexico, together with a catalogue of the
described species and bibliography. Trans. Amer. Entom. Soc.,
Suppl. vol., Pt. I., 1887. [Sec'y Amer. Entomological Society,
Philadelphia. Price $3.00.]

Lubbock, J. --Ants, Bees, and Wasps. Internat. Sci. Series, Vol.
XLII. New York ; P, Appleton & Co. 1882.

BIBLIOGRAPHY, VI 375

III. COLEOPTERA

LeConte, J. L., and G. H. Horn. -- Classification of the Coleoptera of
North America. [Can be purchased of the Secretary of the
American Entomological Society, Philadelphia. Price $2.50.]

Hoffmann, E. - -The Young Beetle Collector's Handbook. New York:
The Macmillan Company. 1897. 178 pp., 20 color plates.

This book deals with European species; but many are closely related
to ours.

Knobel, E. - - Beetles of New England and their kind. A guide to
know them readily. Boston : Bradlee Whidden. 1895.

IV. DIPTERA

Williston, S. W. — Manual of North American Diptera. Second
Edition, 1896. Jas. T. Hathaway, New Haven, Conn. Price
$2.25.

Knobel, E. — The Mosquitoes, Gnats, Crane-flies, Midges, and Flies
of the Northern States. Boston : Bradlee Whidden. 1897.

V. MYRIAPODA

Bollman, C. H. — The Myriapoda of North America. Bulletin U. S.
National Museum, No. 46. 1893.

VI. ARACHNOIDEA

Emerton, J. H. — The Structure and Habits of Spiders. Salem,

Mass. 1878. Price $1.50.
Emerton, J. H. — New England Spiders [of various Families]. In

Transactions Connecticut Academy, New Haven.
Peckham, G. W. and E. G. — North American Spiders of the Family

Attid?e. Transactions Wisconsin Academy of Science, Arts,

and Letters, Madison, Wis. Vol. V1T., 1888. 256 pp., 2 plates.
Peckham, G. W. and E. G. --Some Observations on the Mental

Powers of Spiders. Journal of Morphology, Vol. L, Dec., 1887.
McCook, H. C.-- American Spiders and their Spinning Work: a

Natural History of the Orb-weaving Spiders of the United States,

with Special Regard to their Industry and Habits, 3 vols. 4°,

376 ZOOLOGY

1889-93; 372+479 + 406 pp.; 353 + 401 wood cuts; 35 plates.
Philadelphia : published by the author [Academy Nat. Science,
Philadelphia].

Very valuable and readable treatise.

McCook, H. C. — The Natural History of the Agricultural Ant of

Texas. Philadelphia, 1879.
Kraepelin, K. --Scorpiones and Pedipalpi. Das Tierreich, 8. Lie-

ferung. Berlin : K. Friedlander und Solm. 1899.
Weed, C. M. --A Descriptive Catalogue of the Harvest Spiders

(Phalangiida?) of Ohio. Proc. U. S. National Museum, Vol.

XVI., pp. 543-563, 3 plates. 1893.

CRUSTACEA

Stebbing, T. R. R.--A History of Crustacea, Recent Malacostraca.

International Scientific Series, Vol. 71. New York : D. Appleton

&Co. 1893.
Rathbun, R. - - Natural History of Economic Crustaceans. In Bulletin

U. S. Fish Commission for 1889, pp. 763-830, plates 260-275 and

plate cxxi. 1893.

VII. MALACOSTRACA

Huxley, T. H. — The Crayfish. An Introduction to the Study of

Zoology. International Scientific Series, Vol. XXVIII. 1880.
Faxon, M. - - A Revision of the Astacidae. Part I. : The Genera

Cambarus and Astacus. Mem. Mus. Comp. Zool., Vol. X. No. 4.

Cambridge, Mass. 1885. Ill pp., 11 plates.
Herrick, F. H. - - The American Lobster : A Study of its Habits and

Development. Bulletin U. S. Fish Commission, Vol. XV., for

1895. 252 pp., 54 plates. 1896.
Kingsley, J. S.-- Synopses of North American Invertebrates: III.

The Caridea of North America ; IV. Astacoid and Thalassinoid

Crustacea. American Naturalist, Vol. XXXIII. Sept. and Oct.,

1899.
Benedict, J. E., and Mary J. Rathbun. - • The Genus Panopeus.

Proceedings U. S. National Museum, Vol. XIV., pp. 355-385, 5

plates. 1891.

BIBLIOGRAPHY, X 377

Rathbun, Mary J. --Catalogue of the Crabs of the Family Periceridse

[Spider Crabs] in the U. S. National Museum. Proceedings U. S.

National Museum, Vol. XV., pp. 231-277; 3 plates. 1892.
Rathbun, Mary J. — Synopses, etc. VII. The Cyclometopous or

Cancroid Crabs of North America. American Naturalist, Vol.

XXXIV. Feb. 1900.

VIII. ENTOMOSTRACA

Herrick,C. L.,and C.H. Turner. — Synopsis of the Entomostraca of Min-
nesota : Copepoda, Cladocera, and Ostracoda. Geological and
Natural History Survey of Minnesota. 1895.

Giesbrecht, W., and 0. Schmeil. Copepoda: I. Gymnoplea. Das Tier-
reich, 6. Lieferung. Berlin : R. Friedliinder und Sohn. 1898.
Includes the free-swimming marine species.

WORMS

Cambridge Natural History. Vol. II. [Flatworms, Mesozoa, Werner-
tin i ; threadworms, Sagitta, rotifers, polychset worms, earth-
worms, leeches, Gephyrea, Phoronis, Bryozoa.] New York: The
Macmillan Company. 1896.

IX. OLIGOCH/ETA AND LEECHES, GEPHYREA AND

BRYOZOA

Darwin, Charles.- -The Formation of Vegetable Mould through the
action of Worms, with observations on their Habits. New York :
D. Appleton & Co.

Michaelsen, W. — Oligochseta. Das Tierreich, 10. Lieferung. Berlin:
R. Friedliinder und Sohn. 1900.

Davenport, C. B. — Synopses, etc. I. Fresh-water Bryozoa. Ameri-
can Naturalist, Vol. XXXIII, July, 1899.

X. POLYCH^ETA AND LOWER WORMS

Verrill, A. E. - - New England Annelida. Part I., with Plates III.-XII.
Trans. Connecticut Academy, Vol. IV., Pt. 2. 1881.

378 ZOOLOGY

Andrews, E. A. — Report upon the Annelida Polychreta of Beaufort,
North Carolina. Proc. U. S. National Museum, Vol. XIV., pp.
277-302, 7 plates. 1891.

Johnson, H. P. — A preliminary Account of the Marine Annelids of
the Pacific Coast, with Descriptions of New Species. Proc. Cali-
fornia Acad. of Sciences, Vol. I., No. 5. 1897.

Montgomery, T. H. — Synopses, etc. II.: Gordiacea (Hair-worms).
American Naturalist, Vol. XXXIII. Aug., 1899.

Ward, H. B. - - The Parasitic Worms of Man and the Domestic Ani-
mals, in Report for 1894 of Nebraska State Board of Agriculture.
Lincoln, Neb. 1895.

XL AND XII. MOLLUSCA

The Cambridge Natural History : Vol. III. : Mollusca, by A. H. Cooke.
New York: The Macmillan Company. 1896.

Tryon, G. W., Jr. -- Structural and Systematic Conchology : an intro-
duction to the Study of the Mollusca. 3 vols. 140 plates. Philadel-
phia : published by the author. [Price, $ 6.00 ; for sale by S. R.
Roberts, Glen Ridge, N. J.]

Gould, A. A. - - Report on the Invertebrata of Massachusetts. 2d edi-
tion, by Binney. 1870. 52+ pp. 528 figures.
Devoted to Mollnsca and Tunicata.

Apgar, A. C. — Molluscs of the Atlantic Coast of the United States,
south to Cape Hatteras. [Copies bound in cloth, for sale by
author, Trenton, N. J. Price, $1.00.]
A very convenient book for the pocket.

Ingersoll, Ernest, and J. A. Ryder. — Natural History of Economic
Molluscs of the United States. Bulletin U. S. Fish Commission
for 1889. pp. 687-758. plates 253-259. 1893.

RADIATES

Agassiz, Elizabeth C., and A. Agassiz.-- Seaside Studies in Natural
History. Marine Animals of Massachusetts Bay. Radiates.
Boston : Ticknor & Fields. 1865.

Fewkes, J. W. — An Aid to a Collector of the Coelenterata and
Echinodermata of New England, with cuts. Bull. Essex Insti-
tute, Vol. XXII I., pp. 1-2. [Sec'y Essex Institute, Salem.]

BIBLIOGRAPHY, XIV 379

XIII. ECHINODERMATA

Agassiz, A. — North American Starfishes. Memoirs Museum Com-
parative Zoology at Harvard College, Vol. V., No. 1. 1877.
137 pp. and 20 plates.

Agassiz, A. - - Revision of the Echini. Illustrated Catalogue of the
Museum of Comparative Zoology at Harvard College, No. VII., 2
Parts. 1872-1873.

Lampert, K. - - Die Seewalzen (Holothuroiclea). Eine Systematische
Monographic mit Bestimmungs- und Verbreitungs- Tabellen.
Weisbaden : C. W. Kreidel. 1885. 4°. 310 pp., 1 plate.

Brooks, W. K. — Handbook of Invertebrate Zoology. Boston : Cassino.
1882.

Has au excellent chapter on the development of Echinoderms.

XIV. CCELEXTERATES

Trembley, A. — Memoires pour servir a 1'histoire d'un genre de Po-
lypes d'eau douce a bras en forme de cornes. Leyden. 174-4.
4°. 323 pp., 13 plates.

A remarkable memoir on Hydra ; obtainable from European dealers
in second-hand books.

Agassiz, L. - - Contributions to the Natural History of the United

States of North America. Vols. III. and IV. Second Monograph,

in five parts. - - 1. Acalephs in general. — II. Ctenophorae. — III.

Discophome. - - IV. Hydroidje. - - V. Homologies of the Radiata.

With 46 plates. Boston : Little, Brown & Co. 1860, 1862.
Hincks, T.--A History of the British Hydroid Zoophytes. 2 vols.

London : Van Voorst. 1868. Vol. I. text, — Vol. II. plates. Price

42s.
Allman, G. J. - - A Monograph of the Gymnoblastic or Tubularian

Hydroids. London : Ray Society. 1871. 4°. pp. 450, 23 plates.
Darwin, Charles. - The Structure and Distribution of Coral Reefs.

New York : D. Apple ton & Co. [First published, London,

1842.]
Agassiz, A.-- A Visit to the Great Barrier Reef of Australia in the

Steamer " Croydon," during April and May, 180G. Bull. Museum

380 ZOOLOGY

of Comparative Zoology at Harvard College, Vol. XXVIII.

April, 1898.
Bowerbank, J. S. — A Monograph of the British Spongiadae. 4 vols.,

numerous plates. London : Ray Society. 1861-1882.
Hyatt, A. - - Guides for Science Teaching. III. Commercial and Other

Sponges. Boston : Heath & Co. 1893.
Potts, Edward. — Contributions toward a Synopsis of the American

forms of Fresh-water Sponges, with descriptions of those named

by other Authors and from all parts of the World, with 8 plates.

Proc. Acad. Nat. Science, Philadelphia, 1887, pp. 158-279.

XV. PROTOZOA

Biitschli, 0. -- Protozoa, Bronn's Klassen mid Ordnungen des Thier-
reiches. Leipzig u. Heidelberg : C. F. Winter. 1889.

Kent, W. Saville. - - A Manual of the Infusoria : including a descrip-
tion of all known flagellate, ciliate, and tentaculiferous Protozoa,
British and foreign, and an account of the Organization and
Affinities of the Sponges. 2 vols. and vol. of plates. London : D.
Bogue. 1880-1882.

Leidy, J. — Fresh-water Rhizopods of North America. Washington :
Government Printing Office. 1879.

VERTEBRATES IN GENERAL

Jordan, D. S. — Manual of the Vertebrates of the Northern United
States. 5th Edition. Chicago : McClurg.

Systematic, with keys.

Kingsley, J. S. -- Text-book of Vertebrate Zoology. New York:
Holt & Co. 1899.

About equally devoted to Morphology and Classification.

Darwin, C. — The Variation of Animals and Plants under Domestica-
tion. 2 vols., 2d edition. New York : D. Appleton & Co. 1894.
Domestic races of various vertebrates.

NOTE. — lu many States, the Geological Surveyor Natural History Survey
Reports contain lists of vertebrates found in the State.

BIBLIOGRAPHY, XVIII 381

XVI. PISCES

Goode, G. B. — American Fishes. A popular treatise upon the Game
and Food Fishes of North America, with especial reference to
habits and methods of capture. New York : Standard Book Co.
1888.

Jordan, D. S., and B. W. Evermann.- - The Fishes of North and Middle
America. Bulletin U. S. National Museum, No. 47. 4 parts.
Washington : Gov't Printing Office. 1898. 313(3 pages and atlas.

An exceedingly valuable work, full of biological data ; with keys to
genera and species. Atlas not yet (1899) published.

XVII. AMPHIBIA

Gage, S. H. — Life History of the Vermilion-Spotted Newt (Die-

myctylus viridescens Rat'.). American Naturalist, Dec., 1891.
Ritter, W. E. - - Diemyctylus torosus Esch. The Life History and

Habits of the Pacific Coast Newt. Proc. California Acad. of

Sciences. 3d series. Zoology. Vol.1., pp. 73-114. 1897.
Wilder, H. H. - - Desmognathus fusca (Rafinesque) and Spelerpes bili-

neatus (Green). American Naturalist, Vol. XXXIII., pp. 231-246.

March, 1899.
Kirkland, A. H. - - The Habits, Food, and Economic Value of the

American Toad. Hatch Experiment Station, Amherst, Mass.,

Bull. No. 46. 1897.
Mivart, St. George. - - The Common Frog. Nature Series. London :

Macmillan & Co. 1881.
Boulenger, G. A. — The Tailless Batrachians of Europe. London : Ray

Society. 1897-1898.
Jordan, E. 0. The Habits and Development of the Newt. Jour, of

Morphology, Vol. VIII., No. 2. 1893.
Sherwood, W. L. — The Frogs and Toads found in the Vicinity of

New York. Proceed. Linn. Soc. of New York, No. 10. 1898.

XVIII. REPTILIA

Agassiz, L. — Contributions to the Natural History of the United
States of America. First Monograph. II. North America Testudi-

382 ZOOLOGY

nata ; III. Embryology of the Turtle. Vol. 2. Boston : Little,
Brown & Co. 1857.

To be obtained from dealers in second-hand books.

Taylor, W. E.- -The Box-Tortoises of Xorth America. Proc. U. S.
National Museum, Vol. XVII., pp. 573-588. 1895.

XIX. BIRDS

Newton, Alfred, and Hans Gadow. — A Dictionary of Birds. London :
Adam eSt Charles Black. 1893-1896.

Coues, Elliott. - - Key to Xorth American Birds. Boston : Estes &
Lauriat. 1896. 906 pp.

Ridgeway, R. — A Manual of Xorth American Birds. 2d Ed. Phila-
delphia: J. B. Lippincott Co. 1896.

Chapman, F. M. - - Bird Life. A Guide to the Study of our Common
Birds. Xew York : D. Appleton & Co. 1897.

Parkhurst, H. E. --How to Xame the Birds. Xew York: Charles
Scribner's Sons.

Wright, Mabel 0., and E. Coues. --Citizen Bird. With 111 illustra-
tions by L. A. Fuertes. Xew York : The Macmillan Co. 1898.

Besides these are a score or more good books on American birds,
and guides to their study. The foregoing are representative.

XX. MAMMALIA

Flower, W. H., and Lydekker, R.--An Introduction to the Study

of Mammals, living and extinct. London : Adam and Charles

Black. 1891.
Lydekker, R. - - A Geographical History of Mammals. Cambridge

Geographical Series. Cambridge (Eng.), at the University Press.

1886. [The Macmillan Co., Xew York. Price lO.s. 6^/.]
Mivart, St. George. --The Cat. An Introduction to the Study of

Backboned Animals. Xew York : Scribner's. 1881.

XXI. DEVELOPMENT OF THE FROG

Morgan, T. H. - The Development of the Frog's Egg : An Intro-
duction to Experimental Embryology. Xew York : The Mac-
millan Co. 1897.

APPENDIX III

SYNOPSIS OF THE ANIMAL KINGDOM

GROUPS OF ANIMALS ARRANGED APPROXIMATELY
IN AN ASCENDING SERIES; WITH REFERENCES TO
EVERY FAMILY MENTIONED IN THE MAIN TEXT;
AND WITH DEFINITIONS OF THE CLASSES AND
ORDERS

E. — Owing to the method employed in the text of proceeding from a
type to the allied groups, the systematic relations of the organisms considered
are often obscured. This synopsis is intended to make these, relations clearer.
It can also be used as a systematic index of the book. Moreover, the student
con use it in reviewing his knowledge of the text, and as a key for the deter-
mination of the class in wlijdi a specimen falls. The teacher can employ it as
a guide to collecting illustrative material; for every family mentioned should,
as far as possible, be illustrated by specimens or good .figures.

In the synopsis group-names printed in full-face are phyla ; in
LARGE CAPITALS, classes; in SMALL CAPITALS, orders; in
italics, families. Subphyla, subclasses, and suborders are indicated
by bracketing. Thus [CILTATA] is a subclass. Numbers in
parentheses refer to pages of the text.

PROTOZOA

Animals composed of a single cell ; or, if of several cells, these are
of one kind.

RHIZOPODA. Protozoa with retractile psendopodia: Amoeba(227).

SPOROZOA. Protozoa without appendages; internal parasites
(227).

FLAGELLATA. Protozoa without cilia but with one or more
flagella (225).

383

384 ZOOLOGY

INFUSORIA. Protozoa with cilia or sucking tentacles (222).

[CILIATA]. Locomotor, with cilia: HOLOTRICHA (Parame-
cium, 224); HETEROTRICIIA (224) ; PERITRICHA : Vorticella (225).
[SUCTORIA]. Sessile, with sucking tentacles (225).

OELENTERATA

Animals of radial structure, whose digestive cavity is lined by the
body-wall (205).

[SPONGIARIA]

Ccelenterata whose body-wall is perforated by incurrent pores (205).

[CNIDARIA]

Coelenterata whose body-wall is not perforated by incurrent pores,
and which have nettling organs of some sort (205).

HYDROZOA. Cnidaria whose body is composed of more than two
rays and contains a simple cavity. HYDROMEDUS.E, attached Hydro-
zoa in hydroid stage ; medusa simple : Hydroidce (208) ; Hydrocoral-
lidce (208); Tubularidce (208) ; Campanularidce (209); Traclwmedusce,
(Zygodactyla, 212). SIPHONOPHORA, a free swimming colony of
Hydrozoa (212).

SCYPHOZOA. Cnidaria with many radii, and with radial parti-
tions in cavity of body (214).

CTENOPHORA. Cnidaria with only two radii, and rows of cilia-
plates (219).

SCOLECIDA

Animals of worm-like form, with bilateral, unsegmented body.

PLATYHELMINTHES. Bilaterally symmetrical, soft-bodied
animals, without true segmentation of the body ; flattened in a dorso-
ventral direction, and having body-cavity filled with a loose meshwork
of cells. TURBELLARIA, free-living flatworms whose body is cov-
ered by cilia ; alimentary tract with only one opening to the exte-
rior: Planaria (153). TREMATODA, parasitic, without cilia in the
adult; the mouth leads into a forked food-canal without anus: Dis-
tomum (153). CESTODA, elongated tape-like intestinal parasites,
without mouth or food-canal : Tsenia (156). NEMERTIXI, body more
or less flattened ; food-canal with mouth and anus ; a separate pro-
trusible proboscis (158).

SYNOPSIS OF THE ANIMAL KINGDOM 385

NEMATHELMINTHES. Bilateral, unsegmented, round-worms;
usually with alimentary tract, mouth, and anus: Ascaris (151).

ROTIFER A. Small aquatic Scolecida, with ciliated band around
mouth, and a special organ for attachment, the foot; wheel-animal-
cules.

BRYOZOA. Scolecida in which the ciliated band is carried out 011
a series of tentacles surrounding the mouth ; form colonies by bud-
ding. ENDOPROCTA, Bryozoa with head and stalk, and crown of tenta-
cles surrounding both mouth and anus (1-43). ECTOPROCTA, with
anus outside tentacular corona (143).

MOLLUSCA i

Animals with unsegmented body and without jointed appendages.
Usually with a shell and with a muscular organ of locomotion, the
foot.

LAMELLIBRANCHIATA. Mollusca with nearly symmetrical
body, leaf-like gills, and a shell composed of two valves. Ledidce
(187); Arcidce (184); Mytilidce (184); Aviculidce (185); Pectinidce
(186) ; Ostreidce (187) ; Unionidce (179) ; Cycladidce (180) ; Mactridce
(182); Veneridce (183); Myidce (182); Solenidce (182); Pholadidce
(181); Teredidce (181).

GASTROPODA. Mollusca with head, feelers, and eyes, an un-
paired foot, and a shell that is univalve when present. AMPHINEURA,
with strict bilateral symmetry, no externally visible gills, and usu-
ally a shell composed of eight pieces: Chiton (171). PROSOBRANCHI-
ATA, with gills in front, shelled and operculate : Acmceidce (170) ;
Patellidce (170); Fissurellidce (170); Natiddce (168); Calyptraidce
(Crepidula, 169) ; Littorinidce (167) ; Muricidce (Urosalpinx, 169) ;
Fasciolariidce (Fulgur, 168) . OPISTHOBRANCHIATA, with gills behind
heart; if shelled, without operculum ; JEolidiidce (171). PULMONATA,
breathing by means of lungs, no operculum : Auriculidce (165) ; Lim-
nceidce (166) ; Limacidce (161) ; Helicidce (164) ; Pupidce (165).

CEPHALOPODA. Mollusca with large head, mouth surrounded
by a circle of arms, and funnel-shaped foot. Argonautidce (172);
Spirulidce (172) ; Loliginidce (172) ; Nautilidce (173).

1 This classification, unlike that of the text, follows Cooke in his " Mol-
lusca."

386 ZOOLOGY

ECHINODERMATA

Animals of a prevailingly radial structure, with intestinal wall dis-
tinct from body- wall and with calcareous plates in the skin (192).

CKINOIDEA. Sessile Echinodermata, having a cup-shaped body
(203).

ASTEROIDS A. Star-shaped Echinodermata, with a furrow along
the under side of the arms (193).

OPHIUROIDEA. Star-shaped Echinodermata, with ungrooved
arms (198).

ECHINOIDEA. With armless, globular, or cake-shaped body (199).

HOLOTHUROIDEA. Worm-like, with tentacles around' mouth
(201).

ANNELIDA

Bilateral, segmented worms without jointed legs.

POLYCtLETA. Annelida possessing parapodia on one or more
segments, and with many bristles on parapodia. ERRANTIA, free-
swimming Polychaeta: Autolytus (147), Lepidonotus (147), Xe-
reis (145), Euglycera (147). SEDKNTARIA, Polychaeta which live in
tubes composed of mud, sand, or lime: Cirratulus (149), Amphi-
trite (150), Polycirrus (150), Cistenides (151), Clymenella (150),
Serpula (151).

OLIGOCHJETA. Annelida without parapodia and with few setae ;
living in fresh water or in the ground. LIMICOL^E, aquatic : Xais
(137); Dero (137); Tub if ex (136). TERRICOL.*:, earth-inhabiting:
Allolobophora, Lumbricus (133).

GEPHYREA. Annelida having sessile habits and consequently
without external segmentation in the adult, setae sometimes present.
Phascolosoma (139), Echiurus (139).

HIRUDINEA. Annelida with short rings or none at all and with
a ventral sucker ; "bloodsuckers." Clepsine (141) ; Nephelis (140).

ARTHROPODA

Symmetrical, segmented animals, with jointed appendages.
CRUSTACEA. Typically, aquatic and gill-bearing Arthropoda.
Two pairs of antennae, except in Gigantostraca.

SYNOPSIS OF THE ANIMAL KINGDOM 887

[ENTOMOSTRACA]. Crustacea with varied number of pairs
of appendages ; usually of small size. BRANCHIOPODA, mandibles
without palps, numerous legs (127). TRILOBITA, fossil (130). CLA-
DOCKRA, mandibles palpless, few legs (126). OSTRACODA, palp on
mandible, only two pairs of legs (127). COPEPODA, elongated Crusta-
cea, with only one pair of maxillae ; females with external ovisacs
(127). CIRRIPEDIA, attached Crustacea (barnacles, 129).

[MALACOSTRACA]. Crustacea with nineteen pairs of appen-
dages. AMPHIPODA (112). ISOPODA (112). CUMACEA (112). STO-
MATOPODA (111). PODOPTHALMATA : [MACRURA], large-tailed
Podopthalmata : Candida (104); Astacidce (97); Thalassinidce (105) ;
Paguridce (105) ; Hippidce (107). [BRACHYURA], crabs : Ozyrhyncha
(107) ; Cyclometopa (108) ; Catometopa (HO).

[GIGANTOSTRACA]. Crustacea with five pairs of appen-
dages on cephalo-thorax, abdomen without feet; body ends in a long
telson, Limulus (11-4).

ARACHNOIDEA. Air-breathing Arthropoda without antennae.
ACARINA, rnites (95). PYCNOGONIDA, sea-spiders (95). ARENEIXA,
spiders: Saltigradcv (90); Citigradce (89); Later! ffradce (89); Tubi-
telarice (88) ; Retitelarice (87) ; Orbitelariw (86) ; Terr it elci rice (85).
PHALANGINA, harvest-men (93). ARTHROGASTRA, scorpions (92).

TRACHEATA. Air-breathing Arthropoda, with one pair of
an ten use.

[MYRIAPODAJ. Tracheata with distinct head and abdomen,
all the segments of the abdomen bearing appendages. CIIILOPODA,
centipedes : Scutigeridce (75) ; Lithob.iidce (75) ; Scolopendridce (76) ;
Geophilidce (76). DIPLOPODA, millipedes : Julidce (76) ; Polydesm!<l<c
(77). SYMPHYLA : Scolopendrella (78), Pauroptis (77).

[HEXAPODA]. Tracheata with only three pairs of legs, con-
fined to thorax. ORTHOPTERA, Hexapoda with two pairs of wings,
masticating mouth-parts, incomplete metamorphosis: Forficulidce (9) ;
Blattidce (8); Mantidce (8); Phasmidas (7); Acrid idee (2); Locust idee
(5); GrilUdre (4). XEUROPTERA, Hexapoda with two pairs of net-
veined wings ; biting mouth-parts, metamorphosis complete or in-
complete: Odonata (9); Ephemeridce (10) ; Termitidce (11); Sird'uhe.
Corydalis (12). HEMIPTERA, Hexapoda with two pairs of wings or
none, sucking and piercing mouth-parts, incomplete metamorphosis.
[HETEROPTERA], upper wings leathery: Reduviidce (12>. [HoMOp-

388 ZOOLOGY

TERA], wings alike: Cicada (14) ; [here, also, plant lice and animal
lice]. DIPTERA : Hexapoda with (typically) one pair wings; pierc-
ing" and sucking mouth-parts ; complete metamorphosis. [APHANIP-
TERA], fleas (71). [PUPIPARA] : Hippoboscidce (71). [BRACHYCERA],
true flies : Muscidce (62) ; CEstridce (65) ; SyrpJiidce (66) ; Asilidce (66) ;
Tabanidce (66); Simuliidce (67). [XEMATOCERA], gnats: Ceci-
domyidce (67) ; Culicidce (69) ; Tipulidce (70). COLEOPTERA, Hexa-
poda whose fore wings are modified into wing covers ; hind wings
folded when not in use : Coccinellidce (55) ; Chrysomelidce (54) ;
Cerambycidce (54) ; Curculionidce (53) ; Scolytidce (53) ; Tenebrionidce
(52) ; Lampyridce (51) ; Elateridce (51) ; Buprestidce (51) ; Lamelli-
cornia (49) ; Lucanidce (49) ; Dermestidce (49) ; Silphidce (48) ; Staphy-
iinidce (47) ; Hydrophilidce (47) ; Gyrinidce (46) ; Dytiscidce (46) ;
Carabidce (45) ; Cicindelidie (45). LEPIDOPTERA, Hexapoda with
two pairs of scale-covered wings, sucking mouth-parts, complete meta-
morphosis : Tineidce (29) ; Tortricidce (29) ; Pyralidce (29); Geometridce
(28); Noctuidce (19,28); Bombycidce (26); Arctiidce (24); Xylotropi-
dce (23) ; Spliingidce (22); PapiUonidce (21). HYMENOPTERA, Hexa-
poda with two pairs of membranous wings ; biting and licking mouth-
parts ; complete metamorphosis: [PHYTOPHAGA], plant-eating (38).
[ENTOMOPHAGA] insect parasites (38). [ACULEATA] stinging: For-
micidce (34) ; Fossoria (34) ; Vespidce (33) ; Apidce (31).

CHORDATA

Animals which possess, at some time of life, throat slits and a dor-
sal supporting rod or chorda.

[HEMICHORDA]

Animals of w7orm-like form, showing gill-slits like fishes. Balano-
glossus (251).

[TUNICATA]

Chordata which are either attached or form colonies or both (251).

[VERTEBRATA-ACRANIA]

Free-living fish-like Chordata, but without skull, paired fins, or
heart, and with colorless blood. Amphioxus (251).

SYNOPSIS OF THE ANIMAL KINGDOM 389

[VERTEBRATA-CRANIATA]

Free-living Chordata, with skull and complex brain, and red blood.

CYCLOSTOMI. Eel-like vertebrates without lower jaw, and living
a parasitic life (245).

PISCES. Aquatic vertebrates with gills, without lungs, and with
paired fins instead of legs. SELACHII, skeleton cartilaginous, no
operculum, spiral valve (246). GAXOIDEI, skeleton either cartilagi-
nous or bony, spiral valve and operculum present : sturgeons (247) ;
spoon-bill (247); garpike (248) ; bowfin (248). TELEOSTEI, skeleton
bony, no spiral valve. [ACAXTHOPTERI], dorsal, anal, and ventral fins
with spines, pharyngeal bones distinct : perches (235) ; darters (234) ;
sunfishes (235) ; toadfishes (236) ; sculpins (236) ; silversides (236) ;
sticklebacks (238). [PHARYNGOGNATHI] fins with spines, pharyngeal
bones united. [AXACANTHIXI], fins without spines, ventral fins far
forward: codfishes (239) ; flatfishes (240). [PHYSOSTOMI], fins with-
out spines, ventral fin placed far backward : smelts (230) ; trouts (233) ;
whitefishes (234); catfishes (239); suckers (241); minnows (242);
pikes (242); shads (243); eels (244). [PLECTOGXATHI], intermaxil-
laries and maxillaries united. [LOPHOBRANCHII], body covered with
bony plates : pipefishes (244).

AMPHIBIA (= Batrachia). Vertebrata having no lateral fins (but
instead, legs) ; functional external gills during a part of their life.
URODELA. Amphibia which retain the tail permanently: Sirenidce
(255); Proteidce (257); Amphiumidce (257); Cryptobrancliidce (257);
Amblystomidce (257); Plethodontidce (259); Desmognathidce (259).
Pleurodelidce (254). AXURA, Amphibia which lose the tail in the
adult stage : Pipidce (263) ; Hylidce (263) ; Bufonidce (265) ; Ranidce
(265). GYMNOPHIONA, Amphibia which have no limbs nor tails;
bodv worm-like.

«/

REPTILIA. Vertebrata which breathe exclusively by lungs and
whose skin contains horny epidermal scales or bony plates. CHELOXIA,
trunk enclosed in a bony case : Chelonidce (274) ; Trionychidce (274) ;
Testudinidce (275). SAURIA, shoulder-girdle and sternum present,
usually with eyelids : Chamceleonidce (272) ; lyuanidce (268) ; Varanidce
(269); Lacertidce (270); Helodermidce (270); Ancjuidce (271). OPHI-
DIA, footless scaled reptiles with no shoulder-girdle, sternum, nor

390 ZOOLOGY

movable eyelids: Colubridce (-76) ; Elapidw (277); Crotalidce ('277).
CROCODILINA, large reptiles, with longitudinal vent (279).

AVES. Feathered Vertebrates. CURSORES, Aves with keelless
sternum (307). NATATORES, swimming birds (305). GRALLATORES,
wading birds (305). GALLINACEI, large ground birds with strong,
perching feet and flat nails (304). COLUMBIN.E, short cloven feet and
compressed nails (303). SCANSORES, birds with powerful beak and
feet adapted for climbing (299). CYPSELOMOPH^, cereless birds, with
scaleless metatarsus (301). PASSERES, birds whose metatarsus is
covered with laminae or scales, usually with singing apparatus : Tyran-
/</</«! (295); Aland idee (295) ; Corvine (294) ; Icteridce (293) ; Frincjil-
lidce(284)i Tanagridce (292); Hirudinidce (292); Ampelidce (291);
Laniidte (289) ; Vireonidce (288) ; MniotUidce (287) ; TrnglodtjtidcK
(287); Certhiidce (286); Paridce. (286); Sylviidce (285); Turd idee
(285). RAPTORES, birds with cere, hooked bill, and strong, hooked
claws (298). PSITTACI, birds with cere, high, hooked beak, and
fleshy tongue (parrots, 297).

MAMMALIA. Vertebrates which nourish the young by means of
milk, and are usually covered with hair. MOXOTREMATA, oviparous
mammals (321). MARSUPALIA, provided with a marsupium (322).
EDENTATA, teeth either absent, rudimentary, or without enamel (323).
CETACEA, marine hairless mammals, hind limbs absent (324). UNGU-
LATA, hoofed mammals : even-toed ungulates (326) ; odd-toed ungu-
lates (327); elephants (327). RODENTIA, canines absent, incisors
grow continuously through life (320). CARNIVORA, canines large
(328). INSECTIVORA, small, terrestrial, carnivorous mammals, with
small canines (327). CHEIROPTERA, mammals with flying membrane
between elongated digits (329). PRIMATES, with hands (329).

GLOSSARY

abdomen, in Arthropoda, the hinder-
most of the three divisions of the
body, 59.

aboral, the side of the body opposite
to the mouth, 193.

alveolus, a depression, e.g. the socket
of a tooth, 280.

angulated, forming an angle or sharp
corner; opposed to rounded, 249.

antenna, horn or feeler, one of the
anterior tactile appendages of Ar-
thropoda and Mollusca, 4, 46.

anterior, situated at the front end of
the body.

anus, the posterior opening of the food
canal.

aorta, the main blood-vessel coming
from the heart.

articular, relating to a joint; the
hinge bone of the lower jaw of
fishes, 232.

atripore, the external opening of the
atrium, 249.

atrium, or vestibule, a chamber placed
either in front of the mouth or, in
Chordata, around the gill-slits.

auditory clubs, club-shaped sense or-
gans on the margin of the bell of
jelly-fishes, 221.

basihyal, a bone found in fishes, form-
ing the base of the U-shaped arch
which supports the tongue, 232.

bifid, two-parted.

bivalve, having two valves or shells,
131, 178.

blastula, a stage in the early develop-
ment of the egg when it forms a
hollow sphere, 193.

branchial, relating to the gills.

branchiate, bearing gills, 131.

branchiostegal rays, the bony rays
supporting the membrane below the
bones of the operculum in fishes,
232.

buccal, pertaining to the mouth cavity
or cheeks, 59, 143.

bysxus, a tuft of tough threads spun
from the foot of bivalves and used
for attachment to foreign bodies,
180.

calcareous, consisting of a calcium or
lime compound.

calcified, rendered calcareous by depo-
sition of salts of lime.

callus, a soft substance secreted over
a harder bony material, 175.

calyx, cup.

cambered, concave on the under side,
42.

canine, or canine tooth, the pointed
tooth situated immediately behind
the front cutting teeth, 331.

capsule, a little sac containing a fluid.

carapace, the thick shell or skin cov-
ering the back of Crustacea or Che-
Ionia, 103, 280.

cardinal, belonging to the hinge, as
the teeth of lamellibranch shells,
188.

carnivorous, flesh-eating.

391

392

ZOOLOGY

cephalothorax, united head and thorax.
cere, a waxy sheath at the base of the

bill of certain birds, 315.
chelicera, the first pair of mouth ap-
pendages in the Arachuida, 80.
cilia, microscopic, vibratile processes

of certain cells.
cirrus, a filamentous appendage of the

parapodia of Annelida, 159.
cleavage, the multiplication of cells at

the beginning of the development of

the egg, 193, 336.
clitellum, a thickened glandular ring

sometimes found in the earthworm.
coxa, that joint of an Arthropod leg

which is nearest the trunk, 59.
culmen, the upper ridge of a bird's bill.
cuticula, the tough secreted "skin"

covering arthropods, hydroids, and

other animals.

dentary, a bone of the lower jaw of
fishes which carries the teeth.

dextral, right, applied to right-handed
shells, 166.

diaphragm, a dividing membrane, 119.

elytron, the horny upper wings of
beetles, 59.

enamel, the hard covering of teeth
and some fish scales, 248.

encyst, the act of secreting a cyst or
vesicle, 227.

enteric, pertaining to the enteron or
food canal.

epidermis, the outermost skin of ver-
tebrates; also a superficial horny
secretion over the shells of mol-
lusks, 175.

epimeron, a lateral piece behind the
episternum of insects, 59.

epiotic, one of the bones surrounding
the inner ear in the lower verte-
brates, 232.

episternum, a piece just lateral to the
sternum in the thorax of insects, 59.

epistome, in beetles, a piece above the
mouth, 59.

facetted, composed of numerous small
eyes, making up a compound eye, 78.

femur, thigh of insects, 59.

fertilization, the union of two germ-
cells, 335.

flagellum, a microscopic, lash-like,
vibrating thread of certain Infuso-
ria, 226.

foliaceous, leaf -like.

frontal, applied to a bone of the skull
lying between the orbits, 232.

gastrolith, a calcareous nodule occur-
ring in the stomach of the higher
Crustacea, 103.

gastrula, a stage in development of
the egg just after the digestive cav-
ity has been formed, 193.

gastrulation, the process of forming
the gastrula, 336.

gonad, a germ-producing gland, 221.

gonophore, a sexual zooid, generally
reduced to an exclusively reproduc-
tive function, 212.

gula, the throat plate on under part of
the head of insects, 59.

hsemal, relating to the blood system.

hirsute, hairy, shaggy, 42.

hydranth, the "heads" or zooids of

ahydroid stock, 210.
hyomandibular, a bone which, in

fishes, connects the lower jaw with

the skull, 232.

imago, the adult of an insect.
intermaxillary, the same as premaxil-
lary.

GLOSSARY

393

interopercular, the posterio-inferior
opercular bone of fishes, 232.

jugal, the cheek-bone, 232.

keel, a ridge on the breast-bone of
birds for attachment of flying mus-
cles, 314.

labial, pertaining to the labium.
labiitm, the under lip of insects, 59.
Idbrum, the upper lip of insects, 59.
lamella, a leaf or plate, 58.
lamina, a thin plate.
lancet cell, a lancet-shaped cell on the

hinder margin of the fore wing of

Phytophaga, 43.
larva, an immature but active stage of

development, 10.

Ugula, the front edge of the labium, 59.
liver area, in crabs, the anterio-lateral

area of the carapace in front of the

gill region, 123.

lumen, the central space of a tube.
lunule, a crescentic or heart-shaped

area in front of the beak of some

bivalve shells, 190.

madreporic plate, in echinoderms, a

perforated plate admitting water to

the system of water tubes, 204.
mandible, in arthropods, the most

anterior of mouth parts, 59 ; in

vertebrates, the bone of the lower

jaw.
mantle, the fold of the skin of a mol-

lusk, or cirriped, which secretes the

shell, 160.
manubrium, in jelly-fishes, the mouth

stalk, corresponding in position to

the clapper of a bell, 211.
marsupium, a pouch, in Marsupalia,

on the ventral side of the body,

331.

maxilla, in Arthropoda, one of the
mouth parts immediately following
the mandible, 59 ; in vertebrates, a
tooth-bearing bone of the upper jaw.

maxillary, relating to the maxilla.

maxilliped, one of the foot-like mouth
parts which in arthropods follow
the maxillae.

mentum, the front plate of the labium
in insects, 59.

mesopterygoid, one of the bones form-
ing the base of the skull in bony
fishes, 232.

mesothorax, the middle segment of the
thorax, 59.

metamerism, the fundamental repeti-
tion of parts of the body along the
longitudinal axis, as in earthworms
139.

metapleure, in Amphioxus, a latero-
ventral fin, 249.

metapterygoid, one of the bones form-
ing the base of the skull in bony
fishes and lying behind the mesop-
terygoid, 232.

metasternum, the ventral plate of the
last thoracic segment of insects, 59.

metatarsus, in birds, the foot proper,
315.

metathorax, in insects, the third or
last segment of the thorax, 59.

morula, an early stage of egg develop-
ment when the germ consists of a
nearly solid mass of cells, 330.

moult, to change the skin, as in in-
sects.

myocomma, the thin layer separating
two muscle plates in vertebrates, 246.

myomere, a muscle plate, 246.

nasal, belonging to or forming the

nose, as nasal bones.
neural, pertaining to the nervous

system.

394

ZOOLOGY

neural groove, the groove which marks
in the vertebrate embryo the devel-
oping central nervous system, 261.

nodulous, covered with nodules or
little lumps, 175.

notochord, the axial supporting rod of
chordates, 249.

wsophaaus, the gullet, the part of the

food canal leading to the stomach.
operculum, in gastropods, the horny

plate which closes the aperture ; in

fishes, the gill-cover, 232.
oviduct, the duct which carries eggs

from the body, 120.
oviposit, to lay eggs, as in insects, 53.

palatine, of the palate or roof of the
mouth ; name of a pair of bones
forming the palate, 232.

pallial line, streak formed in a bivalve
shell by the margin of the attached
mantle.

pallial sinus, an incurving of the pal-
lial line to receive the siphon in cer-
tain lamellibranchs.

palp, a secondary sensory outgrowth
of a mouth part of an insect, 59.

paraylossse, a pair of small appendages
of the under lip of insects, 59.

parapodia, the paddling feet of poly-
chsetes, 147.

parasitic, living on the nutritive juices
elaborated by another organism.

parasphenoid , a bone occupying the
base of the skull, 267.

parietal, bones of the middle upper
part of the brain case, 232.

pectinate, comb-like.

pectoral, of the chest ; the chest limbs
of fishes, 246.

pedicellarise, minute forceps-like or-
gans found on some echinoderms,

pelvic Jin, or ventral fin, the hinder

paired appendages of fishes, 246.
penultimate, next to the last.
percoid, like a perch.
perisarc, the outer tough skin of hy-

droids, 211.
pharynaeal, relating to the pharynx

or throat, 252.

polyp, the sessile form of coelenterates.
posterior, situated behind.
premaxilla, the most anterior tooth-
bearing bone of the upper jaw of

fishes, 232.
preopercular, the most anterior of the

bones of the operculum of fishes,

232.
primaries, the large feathers on the

distal joint of a bird's wing, 315.
proboscis, in insects, a sucking tube

connecting with the mouth, 61.
prostermun, the most anterior of the

ventral plates in the thorax of in-
sects, 59.
prostomium, in worms, a lobe of the

body projecting above and in front

of the mouth.
prothorax, the most anterior of the

segments of the thorax of insects,

59.
pseudobranch, in fishes, a rudimentary

gill in front of the first throat slit,

231.
pseudopodia, retractile processes in

Protozoa.
pterotic, one of the ear bones of fishes,

232.
pteryyoid, a bone of the base of the

cranium, 232.
pupa, a stage in insect development

preceding the imago, 11.

quadrate, a bone lying between the
skull and the hinge of the lower jaw
in fishes, 232.

GLOSSARY

395

radii , lines proceeding from a common

centre like the spokes of a wheel,

86.
ramus, a branch or projecting process,

131.
rictus, the corners of the month in

birds, 315.
rostrum, beak, the frontal process of

crustaceans.

scansorial, capable of climbing, 315.

scutellate, composed of plates, 315.

scittellum, the third of the four pieces
composing the upper part of a tho-
racic segment of an insect, 59.

septa, the radial calcareous plates of
a coral, 215.

sinistral, left.

siphon, the drawn-out edges of the
mantle folds of lamellibrauchs, 183;
the strand penetrating the chambers
of the Nautilus shell, also called
siphuncle, 173.

spatulate, shaped like a spatula, or a
paddle.

sphenotic, one of the bones forming
the ear capsule of fishes, 232.

spinnerets, the tubercles through open-
ings in which the spider thread is
spun, 84.

spiracle, one of the openings to the
air-tubes of insects, 59.

spurious, not genuine.

squame, a scale in decapods attached
to the antenna, 124.

sternum, in vertebrates, the breast-
bone, 280; in insects, the ventral
part of a somite, 59.

stigmata, spiracles.

stock, colony, 207.

stolon, a runner from which zooids

bud, 220.
subopercular, the lowermost bone of

the operculum in fishes, 232.
suborbital, a bone in fishes, lying

below the eye, 232.
supraethmeoid, a bone of the nose in

fishes, 232.
supraoccipital, a bone forming the

upper part of the back of the head.
suture, a seam or structural line, 70.
symplectic, a bone uniting the quad-
rate to the bones suspending the

lower jaw, 232.

tarsus, the jointed foot of an arthro-
pod leg, 59.

telson, the tail-piece of a crustacean,
11(5.

tentacle, a projecting tactile organ.

thoracic, pertaining to the thorax or
chest.

tibia, the joint of an insect's leg next
above the tarsus, 59.

trachea, one of the respiratory tubes
of insects, 64.

trjchanter, a joint of the insect leg
lying distal to the coxa, 59.

umbilicus, a depression in the centre
of the base of many spiral shells,
175.

umbon.es, a protuberance just above
the hinge of a bivalve shell, 188.

velum, a circular membrane extend-
ing like a shelf from the margin of
the jelly-fish bell, 211.

viviparous, giving birth to well-de-
veloped progeny, 331.

INDEX

Aardvark, 323.

Abnormalities, lobster, 119; plana-

rians, 155 ; starfish, 196.
Acanthocottus, 236.
Acanthopteri, 252.
Acarina, 95.
Acartia, 128.
Accipiter, 298.
Acineta, 225.
Acipenser, 247.
Acmaea, 170.
Acmaeidae, 177.
Acrania, 252.
Acrididae, 1, 15.
Actitis, 306.
Adalia, 56.
Adeorbidae, 175.
Admiral, 21.
^Eschna, 10.
Agalena, 90.
Agricultural ant, 37.
Alaudidae, 259, 317.
Alligator, 279.
Allolobophora, 114.
Alosa, 243.

Amblystoma, 257, 335.
Amblystomidae, 257, 267.
Ameiurus, 240.
American crossbill, 284.
Amia, 248.
Ammonites, 173.
Amoeba, 227, 229.
Ampelidae, 291, 317.
Ampelis, 291.
Amphibia, 254; distribution of, 255;

metamorphosis of, 260.
Amphioxus, 249, 252.
Amphipoda, 112.
Amphitrite, 149, 150, 159.

Amphiuma, 198.

Amphiumidae, 257, 266.

Amphiura, 198.

Anacanthini, 253.

Anatis, 56.

Ancestry of vertebrates, 248.

Angle wings, 21.

Anguidae, 271.

Annelida, 136.

Anodonta, 191 ; embryo of, 180 ; food

of, 178 ; habitat of, 178.
Anolis, 268.
Auomiidae, 191.
Anthremis, 48.
Ant-eater, 322.
Antelopes, 326.
Authophagus, 47.
Ants, 30, 34, 43; army, 37; colonies

of, 35 ; intelligence of, 35 ; language

of, 36 ; leaf-cutting, 37 ; social life of,

36.

Anura, 255, 262, 266.
Apes, 230.

Aphaniptera, 61, 70.
Aphids, 14.
Aphrodite, 148.
Aphroditidae, 159.
Apidae, 31, 42.
Aplysia, 164.
Apteryx, 307, 308.
Arachnoidea, 92.
Arbacia, 200.
Area, 184.
Archaeopteryx, 314.
Arched crabs, 123.
Archiaster, 195.

Arcidae, 184.
Arctiidae, 24, 41.
Araneina, 80, 95.
Argiope, 80-83, 86;
397

distribution of,

398

ZOOLOGY

83 ; food of, 82 ; spinning habits of,

82.
Argouauta, 172.

Arion, 162.

Ark shells, 162.

Armadillo, 323.

Army ants, 37.

Army worm, 28.

Arthrogaster, 92.

Ascaris, 151.

Asilidae, 66.

Asiphonata, 178.

Asp, 277.

Asparagus beetle, 56.

Assassin bug, 12.

Astacidse, 124.

Astacus, 97-99, 113.

Astartidae, 190.

Asterias, 197 ; distribution of, 192, 197.

Asteriodea, 197, 203.

Astrangia, 216.

Atoll, 217.

Attus, 91.

Auriculidre, 161, 166, 176.

Autolytus, 147, 159.

Aviculidas, 185.

Axolotl, 258, 260.

Baboon, 330.

Badger, 328.

Balauinus, 53.

Balanoglossus, 250, 251.

Balanus, 129.

Bald eagle, 298.

Baltimore oriole, 293.

Banded horse-fly, 66.

Bark-borer, 53.

Barnacles, 102; habits of, 129.

Barn-swallow, 292.

Barrier reef, 217.

Bat, 329 ; food of, 329.

Batrachia, 254.

Batrachus, 236.

Bears, 328.

Beaver, 310.

Beaver parasite, 56.

Bee-moth, 29.

Bees, 30, 31, 42 ; swarming, 32.

Beetle, 44; development of, 44; eco-
nomic importance of, 57 ; food of,
56 ; larval habits of, 45 ; number
of species of, 45.

Bell-hydroid, 209.

Belted kingfisher, 300.

Birds, 281 ; economic importance of,
311 ; extinct, 313; flight of, 310; pro-
tection of, 312; migration of, 309;
teeth of, 314.

Bird's-nest, edible, 303.

Bittern, 305.

Black-fly, 66.

Black lobster, 103.

Black moccasin, 279.

Black snake, 276.

Blattidre, 8, 14.

Blister-beetle, 57. 61.

Blow-fly, 61.

Blue, 22.

Bluebird, 285.

Bluejay, 295.

Boa, 276.

Bobolink, 294.

Boll-worm, 28.

Bomb us, 31.

Bombycidrc, 24, 42.

Bombyx, 24.

Bonasa, 304.

Bony fishes, 252.

Bosminid*, 131.

Bot-flies, 64, 72.

Botryllus, 250.

Bougainvillea, 211.

Bowfin, 248.

Box tortoise, 275.

Brachiopoda, 127, 130.

Braohycera, 61, 63.

Brachyura, 107.

Branchipus, 127, 130.

Brittle-stars, 198.

Brook sucker, 241.

Brown creeper, 288.

Bruchidse, 57.

Bryozoa, 141, 217.

BucciuidsB, 175.

Buck-beetles, 54.

Budding, 217.

Buffalo gnat, 66, 72.

INDEX

399

Bufo, 264.

Bufonidae, 265.

Bugula, 142.

Bull-frog, 266.

Bull-head, 241.

Bullidae, 174.

Bumblebee, 31.

Buprestidae, 51, 60.

Buprestis, 51.

Buthus, 93.

Butterflies, 41 ; broods of, 17 ; habits

and food of, 16; mimicry of , 18-21;

polymorphism of, 17; protective

resemblance of, 18-21.

Cabbage butterfly, 18.

Callianassa, 105.

Callinectes, 109.

Calosonia, 46.

Calyptraeidae, 177.

Cambaroides, 99.

Cambarus, 99, 100, li;i.

Camels, 326.

Campanularian liydroids, 210.

Campanularidfe, 209, 221.

Camponotus, 35.

Canada grouse, 304.

Cancer, 114.

Carabidae, 45-46, 60.

Carchesium, 224; food of, 225.

Cardiidse, 190.

Cardinal grosbeak, 285.

Candidae, 124, 180.

Carolina paroquet, 297.

Carnivora, 328, 331.

Carpenter ant, 35.

Carrion-beetles, 48, 57, 60.

Carrion-fly, 73.

Case-bearers, 29.

Cassowary, .'507.

Catfishes, 239, 253; range of, 239-240.

Catocala, 19, 28.

Catometopa, 123.

Caudina, 201, 203.

Caviare, 247.

Cecidomyidae, 66, 68.

Cedar-bird, 292.

Cedar waxwiug, 291.

Centipedes, 74.

Centrums, 93.

Cephalopoda, 171.

Ceratodus, 249.

Cerambycidfe, 54, 56, 61.

Cerebratulus, 158.

Cerithia, 288.

Certhiidae, 286, 316.

Cestoda, 386.

Cetacea, 324, 331.

Ceuthophilus, 6.

Ceryle, 300.

Chameleo, 272.

Chameleon, 272.

Cheetah, 328.

Cheiroptera, 329, 331.

Chelidon, 392.

Chelonia, 273, 280.

Chelonidfe, 274.

Chestnut-sided warbler, 288.

Che wink, 285.

Chigger, 95.

Chigoe, 71.

Chilopoda, 74; food of, 74.

Chimney-swift, 302: nest of, 302.

Chimpanzee, 330.

Chipping-spar ro w , 2.S5.

Chiton, 171.

Chlorops, 72.

Choloepus, 324.

Chordata, 388.

Chrysomelidse, 57, 61.

Chrysops, 66.

Cicada, 13; pupal case of, 13.

Cicindela, 45.

Cicindelidae, 45.

Ciliata, 229.

Ciona, 250.

Cirratulidae, 159.

Cirratulus, 149, 159.

Cirripedia, 131.

Cistenides, tube of, 150.

Citheronia, 25-26 ; larvae of, 25.

Citigrada?, 89, 96.

Civet-cats, 328.

Cladocera, 127, 131.

Clam, 178.

Claws, abnormal, of lobster, 120.

Clepsiue, 140-141.

400

ZOOLOGY

Click-beetle, 61.

Clisiocampa, 26, 27.

Clothes-moths, 29-30.

Clymenella, 150-159.

Clypeaster, 201.

Cnidaria, 205; fresh-water, 207.

Cobra, 277.

Cobweb spiders, 80.

Coccinellidffi, 55, 61.

Cockatoos, 297.

Cockroaches, 8, 14.

Codfishes, 253 ; habitat of, 239.

Coelenterata, form of, 205.

Colaptes, 301.

Coleoptera, key to families, 58-61;

terminology, 59.
Colonies, of ants, 35 ; formation of, in

Cnidaria, 217-218.
Columba, 304.
Golumbellidse, 176.
Columbidae, 303.
Columbines, 314.
Columbridffi, 276.
Condor, 298, 299.

Congo snake, 256 ; habitat of, 257.
Con urns, 297.
Cooper's hawk, 299.
Copepoda, 127, 131.
Copperhead, 279.
Copris, 50.

Coral cup of Manicina, 216.
Coral, polyps, 215-216 ; reefs, 216-

217.

Coregonus, 233.
Cordylophora, 207-208.
Corvidae, 294, 316.
Cotton-worm, 28.
Cow-bird, 293.
Crab's eyes, 104.
Crab spider, 89, 90, 96.
Crane-flies, 68-69, 73.
Cranes, 305.
Craspedosomida3, 79.
Crassatellidae, 190.
Crayfish, 97, 122 ; development of, 117 ;

edible, 113; food of, 98; moulting

of, 103, subfamilies of, 98-99.
Creepers, 286.
Crepidula, 169-170, 177.

Cribrella, 196-198.

Crickets, 4-5, 15.

Cricket-grasshopper, 6.

Crinoidea, 203.

Crocodile, 279.

Crocodilina, 279-280.

Crossbills, 285.

Crotalidse, 277-278.

Croton bug, 8.

Crow, 294.

Crow-blackbird, 293.

Crustacea, 97, 104, 125.

Cryptobranchidse, 257, 266.

Cryptobranchus, 258.

Ctenophora, 219-220.

Cuckoos, 299 ; laying habit of, 300.

Culex, 68.

Culicidse, 68.

Cumacea, 122.

Curculionidae, 53, 61.

Cursores, 306, 315.

Cuttlefishes, 172.

Cyanocitta, 295.

Cycladidae, 180, 191.

Cyclas, 191; habitat of, 180; distribu-
tion of, 180-181.

Cyclometopa, 123.

Cyclostomi, 252, habits of, 245 ; para-
sitic on fishes, 245-246.

Cyclops, 127-128.

Cyllene, 54-55.

Cypselomorphae, 301, 315.

Daddy-long-legs, 93.

Daphnia, 97, 125; food of. 126; effect

of temperature on, 127.
Daphnidae, 131.
Darcus, 49.

Darters, 234, 252 ; habitat of, 234.
Decapoda, economic importance of,

111 ; eyestalks of, 121.
Deer, 326.

Degenerate flies, 7^.
Dendroctonus, 53.
Dermestida3, 48, 49, 61.
Dero, 137, 144.
Desmognathidas, 259, 267.

INDEX

401

Desmognathus, color of, 250; habitat
of, 2<JO.

Development, of beetle, 44; crayfish,
117; edentates, 333; effect of heat
on, 333; effect of light on, 333; of
egg, 115; frog's egg, 332; fly, 62;
general laws of, 335 ; grasshopper,
3-4 ; lobster, 115-117 ; Spelerpes, 261-
262; starfish, 193-194; Urodela,261.

Diapheromera, 7.

Didelphys, 323.

Diemyctylus, 267; food of, 254; hab-
itat of, 254 ; life history of, 254-255.

Digger wasp, 34, 43.

Diplocardia, 143.

Diplopoda, 74.

Dipnoi, 248, 252.

Diptera, 61,63, 72; injurious toman,
71; scavengers, 72; short-horned,
63; source of disease, 71.

Discontinuous genera, 99-100.

Distomum, 155.

Divers, 60, 306.

Division of labor in Cnidaria, 219;
physiological, 120.

Dodo, extermination of, 314.

Dogs, 328.

Dogfish, 246.

Dolphins, 324.

Doryphora, 55.

Downy woodpecker, 301.

Dragon-fly, 9-10.

Duckbill, 322.

Duck-bill catfish, 247.

Dytiscidae, 4(3, 56, 60.

Dytiscus, 47, 138.

Eagles, 298.
Earwigs, 9.
Earthworm, 132-134; economics of.

135; food of, 134; habits of, 132;

regeneration of, 134; relationships

of, 132 ; resistance of, 134.
Echidna, 322.
Echinarachnius, 201.
Echinoidea, 322.
Echinoids, 204.
Echiurus, 139.

Economic importance, of beetles, 57;
birds, 311; decapods, 111; earth-
worms, 135; parasitic worms, 158;
protozoa, 228; slugs, 162; starfish,
193; smelt, 230.

Ectopistes, 304.

Ectoprocta, 143.

Edentata, 323, 331.

Edentates, discontinuity of, 323.

Edible, birds' nests, 303; Carididae,
114; crabs, 108-109, 113; crayfish,
113; lobsters, 113.

Eels, 253; description, distribution,
reproduction, 244.

Egg, fertilization, 336 ; masses of tent
caterpillar, 26; nauplius, 115.

Egrets, extermination of, 305.

Elapidae, 277.

Elaps, 277.

Elateridae, 51, 61.

Elephants, 327.

Endoprocta, 143.

Enemies of lobster, 102.

English sparrow, 281; food of, 282;
spread of, in America, 281-282.

Engraver beetles, 61.

Ensis, 182.

Entomophaga, 43.

Eutomostraca, 97, 125.

Eolis, 171.

Ephemeridae, 10.

Epiera, 80; web, 87.

Erycinidae, 190.

Euglena, 225-226, 229.

Euglycera, 146, 159.

Eunicidae, 159.

Eupagurus, 106.

Eupomatis, 235.

Eutamia, 276.

Even-toed ungulates, 326.

Exotic species, increase of, 283.

Extinct birds, 313.

Eyestalks of decapods, 121.

Falcons, 298.
Fasciolariidae, 175, 177.
Felis, 328.
Fiddler crabs, 110, 123.

402

ZOOLOGY

Fireflies, 51-52, 58, 60.

Fishes, 230.

Fissurella, 170.

Fissurellidte, 177.

Flagellata, 225, 229.

Flatfishes, 239-240, 253.

Flatworms, 153.

Fleas, 61, 70.

Flicker, 301.

Flies, 61 ; degenerate, 70 ; development
of, 62; food of, 62; plant-infesting,
72 ; mimicry in, 65 ; parasites of, 63 ;
parasitic, 70 ; trachea of, 63.

Flight of birds, 310-311.

Flycatchers, 295.

Food of, beetles, 56; butterflies, 16;
crayfish, 98; earthworm, 134; fly,
62; hydra, 207; mouse, 319; English
sparrow, 282; starfish, 193; whale,
325.

Forficulidffi, 9.

Formicidse, 34-35, 43.

Fossil, birds, 314; lizards, 272; man,
331.

Fossoria, 34, 43.

Fowls, origin of, 305.

Fox-sparrow, 285.

Fresh-water clam, 178.

Fresh-water Cuidaria, 207.

Fresh- water jelly-fishes, 208.

Fringillidae, 284, 317.

Fringing reefs, 217.

Fritillaries, 22.

Frog, development of, 333; postem-
bryonic development of, 334.

Frog's egg, development of, 332 ; heal-
ing of, 334; regeneration of, 334;
size of, 332.

Fulgur, 168, 169, 175.

Fundulus, 242.

Gadus, 239.
Ganoidei, 247-252.
Ganoids, 252.
Garpike, 248.
Garter snake, 27(5.
Gasterosteus, 237-238.
Gastropoda, 160, 161.

Gall-gnats, 66, 72.

Gall-flies, 31.

Gall-producing Hymenoptera, 43.

Gall- wasps, 31, 38-39.

Galls on plants, 67.

Galley-worm, 76.

Gallinacei, 304, 314.

Gallns, 305.

Gebia, 105.

Geese, 306.

Gelasimns, 110-111.

Genera, discontinuous, 99-100.

General laws of development, 335.

Geometridse, 28, 42.

Geomys, 320.

Geophilus, 76.

Geothlypis, 289.

Gephyrea, 138-139, 141.

Germ theory of Infusoria, 223.

Gibbous, 330.

Gila monster, 270-271.

Giraffes, 326.

Glossina, 65.

Glow-worm, 271.

Glyceridse, 159.

Gnats, 61.

Goat-suckers, 301, 303.

Golden-crowned kinglet, 287.

Gopher, 320.

Gorilla, 330.

Grallatores, 305, 314.

Grapta, 21.

Grasshopper, 1-4 ; development of,

3-4.

Grass spiders, 90.
Gray-veined white, 18.
Great horned owl , 299.
Great northern shrike, 290.
Green frog, 266.
Grillidae, 4-5, 15.
Grillus, 5.

Ground-beetles, 45-46.
Grouse, 304.
Gryllotalpa, 5.
Guinea fowl, 304.
Gulls, 306.

Gymnophioua, 255, 266, 389.
Gypsy moth, 28.
Gyrinidse, 46, 60.

INDEX

403

Habitat, of Anoclonta, 178; butter-
riles, 1(5; Daphnia, 12(5; earthworms,
132 ; Hydra, 205 ; slug, 161 ; Uuio, 178.

Habits, of Acrididse, 1; mouse, 319;
rat, 319.

Hadrosaurus, 273.

Hair streaks, 22.

Hairy ant-eater, 323.

Hairy woodpecker, 301.

Halistemma, 213.

Hard-shelled clams, 190.

Hares, 321.

Hawkbill-turtles, 274.

Hawk-moths, 22, 41.

Hawks, 298.

Heating of frog's egg, 334.

Heat, effect on development, 333.

Helicidae, 101.

Helix, 161-165 ; introduction of nemo-
ralis, 164; variations in, 164.

Hellbender, 257, 258.

Heloderma, 270, 271.

Hemiptera, 12, 67.

Hen clams, 189.

Hermit crabs, 105, 107, 123.

Herons, 305.

Hessian-fly, 67, 68, 82.

Hesperornis, 313.

Heterandria, 242.

Heteroptera, 12.

Heterotricha, 224, 229.

Hippa talpoides, 107.

Hippidae, 107, 123.

Hippoboscidae, 70.

Hippopotamus, 326.

Hirudinidae, 292, 316.

Holothurians, 201.

Holothuroidea, 204.

Holotrichia, 229.

Homarus, 100, 113.

Homoptera, 13-14.

Honey bees, 32-33.

Horn-pout, 241.

Horned corydalis, 12.

Horned fly, 72.

Horned toad, 269.

Hornet, 34.

Horses, 327; fossil, 327.

Horse-flies, 65, 72.

House-fly, (il.

House wren, 288.

Humming-birds, 301.

Hydra, 205, 335; description of, 205-

207; food of, 207; habitat of, 205;

regeneration of, 219.
Hydractiuia, 209.
Hydrocorallidre, 208, 220.
Hydroidae, 220.
Hydromedusfe, 212, 220.
Hydrophilidae, 60.
Hydrophilus, 47.
Hydrozoa, 220.
Hyenas, 328.
Hygrotrechus, 12.
Hylidre, 263.
Hymenoptera, 30, 72; gall-producing,

43 ; parasitic, 38, 43 ; plant-eating, 43.
Hypotricha, 229.

Ichneumon flies, 30.
Icteridffi, 293, 317.
Idylia, 219.
Iguanidae, 268-2(59.
Importation of mouse, 318.
Increase of exotic species, 283.
Indigo bird, 285.
Infusoria, 222, 229.
Insectivora, 327, 331.
Intelligence of ants, 35.
Iphiclides, 18.
Isopoda, 112.

Jay, 294.

Jelly-fishes, fresh-water, 208; life his-
tory of, 210; salt-water, 208.
Jigger, 71, 95.
Jingle shells, 191.
Julidae, 79.
Julus, 76, 77, 79.
Jumping mice, 321.
Jumping spiders, 90, 91, 96, 321.
June-bugs, 50.

Kallima, 20.
Katydids, (5, 15.

404

ZOOLOGY

Key to classes of Echinodermata, 203 ;
principal families of Acrididae, 2 ;
Coleoptera, 58-01; Hymeuoptera,
42-43 ; Lamellibrauchiata, 188 ; Lepi-
doptera, 41-42; Myriapods, 78; Or-
thoptera, 14; Polychaeta, 159; Pul-
monates, 161 ; principal genera of
Daphnidae, 126; Laniellibranchiata,
191 ; to genus Lithobius, 79 ; to chief
orders of Birds, 314-317; Entomos-
traca, 130; Gastropoda, 100; Mala-
costraca, 122 ; species of Earthworm,
143; of Lithobius, 79.

Killer whale, 325.

Killitish, habits, food of, 242.

Kingbird, 290.

Kingfisher, 300.

Kitchen-middens, 188.

Lacerta, 270.

Lacertidae, 270.

Lachnosterna, 50.

Ladybird beetles, 55, 61.

Lamellibrauchiata, key to families of,
188.

Lamellicornidae, 58.

Lamellicorn beetles, 49-50, 58 ; leaf-
eating, 50 ; scavengers, 50.

Lamprey, 245.

Lamprey eels, 252.

Lampyridae, 51, GO.

Land-locked fishes, 230.

Language of ants, 36.

Laniidae, 289, 316.

Lanius, 290.

Larks, 295.

Larval habits, of beetle, 45; grass-
hopper, 3-4 ; lobster, 116.

Laterigradse, 89, 96.

Leaf beetles, 61.

Leaf-cutting ants, 37-38.

Leaf-eating lamellicorns, 50.

Leaf-hopper, 44.

Leaf-miners, 42.

Leaf-rollers, 42.

Lecanium, 13.

Ledidae, 187, 188, 191.

Leeches, 139-140.

Lemurs, 329.

Leopards, 328.

Leopard frog, 266.

Lepidonotus, 147-148, 159.

Lepidosteus, 248.

Libinia, 108.

Life history, of mosquito, 68; Union-
idae, 179-180.

Light, effect of, on development, 333.

Limacidae, 161.

Limacinidae, 177.

Limax, 161-164.

Limnaea, habitat of, 166.

Linmaeidae, 161.

Limpets, 170, 177; economic impor-
tance of, 170.

Limulus, 114.

Line-weavers, 87, 96.

Liobunum, 93-94.

Lions, 328.

Lithobiidae, 78.

Lithobius, 74, 75, 78, 79.

Littorina, 167-108, 175; littoria, intro-
duction, 107 ; range, 107 ; spread, 283.

Littorinidae, 175.

Liver-flukes, 153-154; life history of,
154-155 ; stages of, 150.

Lizards, 208 ; fossil, 272.

Llamas, 326.

Lobster, 100, 103, 113; abnormalities
in, 119; development of, 115; em-
bryos of, 110 ; enemies of, 102 ; moult-
ing of, 103; protection of, 102.

Locust borer, 55.

Locusts, 14, 15; of old world, 2.

Locustidae, 1, 15.

Loligo, 172.

Long-horned beetles, 54.

Long-horned grasshoppers, 15.

Long-horns, 61.

Lophobranchii, 244, 253.

Lost parts, regeneration of, 118.

Louse-fly, 70.

Loxia, 284.

Lucanidae, 49, 58.

Lucanus, 49.

Lucius, 243.

Lumbriculidae, 144.

INDEX

405

Lycaenas, 22.
Lycosa, 91.
Lycosidae, 92.
Lynceidae, 131.
Lynx, 328.

Macaque, 330.

Macrodactylus, 50.

Macrolepidoptera, 22.

Mactra, 183.

Mactridse, 182, 189.

Maggots, rat-tailed, 65.

Malacostraca, 97, 111, 125.

Maldanidae, 159.

Mammalia, 318, 331.

Manatee, 324.

Mandrills, 330.

Mantidae, 8, 14.

Margaritana, 191.

Marmosets, 324.

Marsupalia, 322, 331.

Martens, 328.

Maryland yellow-throat, 288, 289.

May beetles, 50.

May-flies, 10.

Meadow grasshopper, 6.

Meadow-lark, 293.

Meal-beetles, 61.

Meal-worms, 52.

Mealy bng, 14.

Measuring-worms, 42.

Medusa, 211.

Megascops, 298.

Melampus, 161, 176.

Melanoplus, 2.

Meloidae, 61.

Melophagus, 70.

Metacrinus, 202.

Metallic wood-borers, 51, 60.

Metamorphosis, of Amphibia, 260 ; Ano-
donta, 180; beetles, 44; crayfish,
117; dragon-flies, 9; fly, 63; frog,
335 ; Hemiptera, 12 ; Lepidoptera, 16 ;
liver-fluke, 152 ; lobster, 116 ; Neu-
roptera, 11; Orthoptera, 1 ; starfish,
194.

Metridium, 214, 215.

Microhydra, 208.

Microlepidoptera, 22.

Midgets, 62.

Migrations of birds, 309.

Milk-snake, 276.

Mimicry, 18-21 ; flies, 65.

Minks, 328.

Minnows, 242, 253.

Minyas, 214.

Mniotilidae, 287.

Mocking-bird, 287.

Modiola, 185.

Mole crabs, 123.

Mole cricket, 5.

Mollusca, 160, 178.

Monarch, 22.

Mongoose, 328.

Monkeys, 330.

Monotremata, 321.

Morone, 234.

Morula, 336.

Mosquito, 68.

Motacillidae, 317.

Moths, 22.

Moulting, 103.

Mourning cloak, 21.

Mouse, distribution of, 318 ; food of, 319 ;

habits of, 319; importation of, 318.
Mud-daubing wasp, 82.
Mud eel, 255, 256.
Mud fishes, 252.
Mud puppy, 257.
Mud wasps, 34, 43.
Muricidae, 169, 175.
Mus, 321.

Muscidae, 61, 64, 72.
Muskallunge, 242.
Muskrat, 321.
Musk turtle, 276.
Mussels, 120, 190.
Mustelus, 246.
Mya, 182, 183.
Myidre, 182, 189.
Myrmica, 37.
Mytilidre, 184, 190.

Naidse, 144.
Nais, 137-138, 144.
Narcomedusae, 221.

406

ZOOLOGY

Natatores, 305, 314.

Natica, 168, 175.

Naticidre, 175, 176.

Nautilus, 173.

Nebalia, 122.

Necturus, 257, 335.

Nemathelminthes, 386.

Nematocera, 61, 66.

Nematus, eggs of, 40.

Nemertini, 158.

Nephelis, 140.

Nereidae, 159.

Nereis, 136, 138, 145, 146, 159; food
arid habitat of, 145.

Nest, of barn-swallow, 292; of chim-
ney-swift, 302 ; of pewee, 296.

Neuroptera, 11-12.

Newts, 254, 362 ; how to capture, 255.

Night-hawk, 303.

Nightingale, 285.

Nile varan us, 269.

Noctuidse, 27-28,41.

Norwegian lobster, 113.

Notodelphys, 263.

Notolophus, 28.

Nuculidse, 191.

Nuthatches, 286.

Nymphs, 21.

Obelia, 210.

Odd-toed ungulates, 327.

Odonata, 9.

(Estridfe, 64.

Oligochreta, 132, 136, 139.

Oniscus, 112.

Operculura, of worms, 151; of fish,
233.

Ophiclia, 280.

Ophion, 39.

Ophiuroidea, 198, 203.

Opisthobranchiata, 161.

Opisthobranchs, 1(54, 170-171; degen-
eration of shell of, 162.

Opossum, 322-323.

Orang-utan, 330.

Orbitelariae, 86, 96.

Orb-weavers, 86, 96.

Orbweb, diagram of, 86; of Epiera,
87 ; nomenclature of parts of, 86.

Orbweb spiders, 80.

Orca, 325.

Orchard oriole, 293.

Orchelium, 6.

Ornithorhynchus, 321.

Orthoptera, 1.

Orthosoma, 54.

Osmerus, 230.

Ostracoda, 127, 131.

Ostrea, 187.

Ostreid?e, 190; economic importance
of, 187.

Ostrich, 307; habits of, 307-308.

Otter, 328.

Owlet moths, 27-28, 41.

Owls, 298.

Oxen, 326.

Oxyrhyncha, 123.

Oyster drill, 169.

Oysters, 187-188, 190.

Paddlefish, 247.

Paguridre, 105, 123.

Painted turtle, 276.

Palremonetes. 104.

Palinurus, 101.

Pallene, 95.

Palm-crab, 107.

Pandorida-, 189.

Pandorus, 23.

Panopeus, 109.

Papilionidre, 41.

Papilio,21.

Paramecium, 222, 229; food of, 224;

fusion of, 229; habitat of, 224; rate

of division, 229.
Parasites of fly, 63.
Parasitic, flies, 70; Hymeuoptera, 43;.

worms, 158.
Paridse, 286, 316.
Parrots, 297.
Partridges, 304.
Passenger pigeon, 303.
Passer, 281-282.
Passeres, 315.

INDEX

407

Patella, 170.

Pauropus, 77.

Pearl-bearers, 185 ; fishery, 185-186.

Peccaries, 326.

Pecten, 186.

Pectinatella, 143.

Pectinidfe, 190-191; locomotion of, 186.

Pedicellina, 141.

Pelicans, 306.

Perches, 235, 252.

Peritricha, 229.

Petrels, 306.

Petricolidae, 189.

Petromyzon, 245.

Pewee, 296; nest of, 296.

Pheasants, 304 ; range of, 305.

Phalangina, 93.

Pharyngognathi, 93.

Phasmidse, 7, 15.

Phasmomantis, 8.

Philampelus, 23.

Philinidae, 176.

Phoca, 328.

Pholadidse, 181, 188.

Pholis, 237.

Photuris, 52.

Phrynosoma, 269.

Physa, 161, 167; food of, 166; habitat

of, 166.
Physalia, 213.

Physiological division of labor, 120.
Physostomi, 253.
Phytophaga, 43.
Pickerels, 242.
Pickerel frog, 266.
Pieris, 21 ; rapae, increase and spread

of, 283.
Pigeons, 304.
Pigs, 336.
Pike, 242.
Pimpla, 37.
Pin worm, 153.
Pine borers, 53.
Pinnotheres, 109-110.
Pipa, 262 ; with embryos, 263.
Pipe-fishes, 244, 253.
Pipidffi, 263.
Piranga, 293.
Piroplasma, 228.

Pisidium, 191.

Pithecanthropus, 331.

Planarians, abnormalities of, 155 ;

fresh-water, 153; regeneration of,

154.
Planorbis, 167; eggs and habitat of,

167.

Plant-eating hymenoptera, 43.
Plant galls, 67.
Plant lice, 14.
Platyouichus, 110.
Platypsylla, 56.
Plectognathi, 253.
Plethodon, 259.
PlethodontidfB, 259, 267.
Pleurodelidse, 267.
Pleurotomidse, 176.
Plovers, habitat of, 305.
Plnmatella, 142.
Plume-moths, 42.

Podophora, food and habitat of , 225.
Podopthalmata, 122.
Poisonous spiders, 91-92.
Polistes, 33.
Polychseta, 136, 148.
Poly-cirrus, 149-150.
Polydesmidse, 79.
Polydesmus, 77, 79.
Polymorphism in butterflies, 17.
Polyphemidse, 131.
Polyxenidre, 78.
Polyzoniidae, 79.
Pond snail, habitat of, 166.
Portuguese man-of-war, 213-214.
Postembryonic development of frog,

334.

Pouched gopher, 320.
Prairie dog, 320.
Prawns, 104, 124.
Praying-mantis, 8, 14.
Primates, 329, 331.
Prionus, 54.
Prosobranchiata, 160.
Protection, of birds, 312; of lobster,

102.

Protective resemblance, 18-21.
Proteidae, 257, 266.
Protozoa, 222 ; relations to man, 228;

reproductive capacity of, 228.

408

ZOOLOGY

Psammobiidae, 189.

Psittaci, 297, 315.

Psoroptes, 94.

Pterophoridse, 42.

Pulex, 70.

Pulmonata, 160, 161, 164, 165; aquatic,

166.

Pumpkin-seed sunfish, 236.
Pupa, 16, 165.
Pupidse, 385.
Pupipara, 61.
Purple grackle, 294.
Pyralidae, 29, 42.
Pyramidellida?, 174.

Quail, 304.
Quadrate, 232.
Quiscalus, 294.

Raccoons, 328.

Races of tame mice, 319-320.

Rails, 305.

Rana, 265.

Ranidae, range of, 265.

Raptores, 298, 315.

Rat, habits of, 319.

Rat-tailed maggots, 65.

Rattlesnake, 278.

Rays, 252.

Razor clams, 188.

Razor shell, 182.

Red-eyed vireo, 289-290.

Red-headed woodpecker, 301.

Reefs: barrier, coral, fringing, 217.

Redpoll warbler, 288.

Red-winged blackbird, 293.

Reduvius, 12.

Regal moth, 25.

Regulus, 287.

Regeneration, of earthworms, 134 ; flat
worms, 153 ; frog's egg, 334 ; Hydra,
219 ; lost parts of lobster, 118 ; plan-
arians, 154.

Relationships of earthworms, 132.

Reproductive capacity of protozoa, 228.

Reproduction, 332.

Reptiles, 268.

Resistance of earthworms, 134.

Retitelariae, 87, 96.

Rhea,307.

Rhinoceroses, 327.

Rhizopoda, 229.

Rice bird, 294.

Rissoidfe, 174.

Robber-flies, 65, 72, 73.

Robin, 285.

Rock-eel, 236, 237.

Rodentia, 320, 331.

Rodents, 320.

Rose-breasted grosbeak, 285.

Rose-bug, 50-51.

Round worms, 151.

Routes of bird migration, 309.

Rove beetles, 47, 57, 58.

Ruby-crowned kinglet, 285.

Ruby-throated humming-bird, 302.

Ruffed grouse, 304.

Runners, 60.

Running beetles, 45. .

Running spiders, 91, 96 ; habits of, 89,

Salmo, 233; skull of, 232.
Salmonidae, 230, 231 ; distribution of,

231 ; spawning of, 231-233.
Salamander, 259.
Saltigradse, 90, 96.
Sand dollars, 200-201.
Sandpipers, 305.
Sauria, 268, 280.
Saw-fly, eggs of, 40; larvae, 39.
Saxicavidffi, 189.
Saxicolidre, 315.
Scalariidae, 174.
Scale bug, 14.
Scale insect, 13 .
Scaled worm, 148.
Scallops, 190.
Scaly ant-eater, 323.
Scansores, 299, 315.
Scaphandridfe, 176.
Scarlet tanager, 293.
Scavengers, Diptera, 72; Lamelli-

corns, 50.

Schizopod larva, 116.
Schizoneura, 14.
Scolopendra, 75, 76, 78.

INDEX

409

Scolopendrella, 78.

Scolopendridw, 78.

Scolytidse, 53, 61.

Screech owl, 298, 299.

Sculpin, 236, 252.

Scutigera, 75, 78.

Scutigeridse, 78.

Scyphozoa, 214,220.

Sea-cows, 324.

Sea-crayfish, 113.

Sea-cucumbers, 204.

Sea-lilies, 203.

Sea-lions, 329.

Sea-mats, 218.

Sea-mouse, 148.

Sea-spiders, 107.

Sea-squirts, 218.

Sea-urchins, 204; food and habitat of ,

199-200.

Sea-walnuts, 219.
Seal, 328, 329.
Searcher, 46.

Sedentary polychseta, 148.
Selachians, 246.
Selachii, 252.
Semelidre, 189.
Serpent stars, 203; description and

habitat of, 199.
Serpula, 151, 159; tube, 151.
Serpulidre, 159.
Sertularia, 210.
Sexton beetles, 48.
Sexual dimorphism of spiders, 92.
Shad, 253 ; range, 243-244.
Sharks, 252.

Sharp-shinned hawk, 298.
Sheep, 326.
Sheep-tick, 70.
Sheep scab, 94.
Shipworms, 188.
Short-horned diptera, 64.
Short-horned grasshoppers, 51.
Short-winged beetles, 47.
Shrews, food of, 327.
Shrike, 289.
Shrimps, 104, 124; value of catch,

111.

Sididae, 131.
Silk-worms, 42.

Silpha, 48.

Silphida3, 48, 60.

Silversides, 236, 252.

Simia, 330.

Simuliidse, 67.

Simulium, 67.

Siphonophora, 212-213, 220.

Siphonata, 178.

Siren, 255, 256.

Sirenia, 331.

Sirenidre, 255, 266.

Sitta, 287.

Sittidae, 316.

Skunks, 328.

Sloths, 323; two-toed, 324.

Slugs, 132, 160, 162; apparent absence

of shell in, 162; economics of, 162;

food of, 161-162; habitat of, 161;

species of, 162.
Smelt, 230, 253; artificial propagation

of, 231 ; economic importance of, 230;

habitat of, 230; range of Atlantic

form of, 230-231 ; value of Atlantic

fishery, 231.
Snapping beetles, 51.
Snapping turtles, 275.
Snipes, habitat of, 305.
Snout beetles, 61.
Snow-bird, 285.
Snowy owl, 299.
Social bees, 31.
Social life of ants,
Soft-shelled clams,
Solaster, 197-198.
Solemyidae, 189.
Solenidas, 182, 188.
Song-sparrow, 285.
Song-thrush, 285.
Sow-bug, 112.
Spanish fly, 58.
Sparrow-hawk, 299.
Speckled tortoise, 276.
Spelerpes, color of, 259; development

of, 261-262 ; habitat of, 260.
Sphex, 82.
Sphingidre, 22, 41.
Sphinx moth, 23.
Spiders, 80, 92; ballooning habits of,

83-84; classification of, 85; food of,

410

ZOOLOGY

82; poisonous, 91-92; sexual di-
morphism of, 92; spinning habits of,
83; wandering, 88.

Spider-crabs, 107, 123.

Spider webs, economic importance of,
90.

Spinning habits, in spiders, 83.

Spiny ant-eater, 322.

Spiny lobster, 101.

Spirulidaj, 171.

Spizella, 285.

Sponges, 205.

Spontaneous generation theory, 223.

Spoonbill, habitat of, 247.

Spore of Infusoria, 223.

Sporozoa, 227, 229.

Spotted sandpiper, 306.

Spreading adder, 276.

Spring azures, 18, 22.

Square crabs, 123.

Squash bug, 13.

Squids, 171.

Squilla, 111.

Squirrel, 320.

Stable-fly, 61.

Stag-beetles, 49, 58.

Staphylinidse, 47, 58.

Starfish, 192,203; abnormalitiesof , 196;
development of, 193-194; distribution
and habitat of, 192 ; economic im-
portance of, 193 ; food of, 193 ; larval
stages of, 195; metamorphosis of,
195 ; systematic position of, 192.

Stentor, 229 ; habitat of, 224-225.

Sterna, 307.

Sticklebacks, 238, 252.

Stomatopoda, 111, 122.

Storks, 305.

Strongylocentrotus, 199.

Sturgeons, 247; economic importance,
habitat, food of, 247.

Suckers, 241, 253.

Suctoria, 225, 229.

Sunfish, 235, 252.

Swallows, 292.

Swarm of bees, 32-

Swifts, 301, 302.

Sycon, 206.

Syllidse, 159.

Sylvicolidae, 317.
Sylviidae, 285, 315, 316.
Synapta, 202, 203.
Synotus, 329.
Syrphidte, 66, 73.
Syrpus, 64.

Tabanidre, 65.

Tabanus,65, 66.

Tasnia, 157.

Talorchestia, 112.

Tanagers, 292.

Tanagridre, 292.

Tapeworm, 156; human, 157.

Tapirs, 327.

Tarantula, 92.

Teeth of fossil birds, 314.

Teleostei, 252.

Tellinidse, 190.

Tenebrio, 52.

Tenebrionidre, 52, 61.

Tent caterpillars, 26; egg masses of,

26 ; nests of, 27.
Terebellidfe, 159.
Teredidre, 181, 188.
Teredo, 181.
Termes, 11.
Termites, 11.
Terns, 306, 307.
Terrapene, 275.
Territelariffi, 85, 95.
TestudinidaB, 275.
Texas fever in cattle, 228.
Thalassinidae, 105, 124.
Theclas, 22.

Theridium, 80, 82; food of, 82.
Thomisus, 90.
Thrushes, 385.
Tineidae, 29, 42.
Tigers, 328.
Tiger-beetles, 45.
Tiger-moths, 24, 41.
Tipulidse, 68-69.
Titmice, 286.

Toadfishes, 252; habitat of, 236.
Tornatinidfe, 176.
Tortricidre, 29, 42.
Toucans, 299.

INDEX

411

Trachea of fly, 63.

Tracheata, 387.

Trachina, 152, 153.

''"rachomed us<e , 221.

Jrap-door spiders, 86.

Tree-hoppers, 14.

Trematoda, 385.

Trepangs, economic importance of,

202.

Tree-sparrow, 285.
Tree-toad, 265.
Triangular crabs, 123.
Triforidse, 177.
Trilobites, 130.
Trionychidre, 274.
Trionyx, 275.
Trochidse, 175.
Trochilus, 302.
Troglodytidse, 287, 316.
Troglodytes, 288.
Trouts, 233, 253.
True bugs, 12.
True wasps 83.
Tsetse-fly, 64.
Tube-forming worms, 102.
Tube-weavers, 88, 96.
Tnbifex, 136, 144.
Tubificidse, 144.
Tubitelarire, 88, 96.
Tubularia, 208.
Tubularian hydroid, 210.
Tubularidaj, 208, 221.
Tumble-bugs, 50, 57.
Tunicata, 218, 251.
Tunnel-weavers, 85, 95.
Turbellaria, 385.
Turdidae, 285, 315, 316.
Turdus, 286.
Turkey-buzzard, 299.
Turkeys, 304; wild, 305.
Turtles, 273; range of , 274.
Tussock moth, 28.
Twin-spotted sphinx, 23.
Tyranuidfu, 295, 315.
Tyraimus, 296.

Unau, 324.

Ungulata, 325, 331; even-toed, 326;
odd-toed, 327.

Unio, 178, 191.

Unionidfe, 179, 180, 191.

Urodela, 255, 26(5 ; development of, 261.

Urosalpinx, 169, 175.

Varanida?, 269.
Variations in Helix, 165.
Veneridae, 180, 183, 190.
Venus, 183.
Vermetidre, 174.
Vertebrates, ancestry of, 248.
Vespa, 34, 35.
Vesper sparrow, 285.
Vesperidse, 43.
Vespidae, 33.
Vireo, 288, 290.
Vireonidse, 288, 316, 317.
Volvox, 226, 227.
Von Baer's law, 336.
Vorticella, 225, 229.
Vultures, 298, 299.

Walking-sticks, 7, 15.

Wall-eyed pike, 235.

Walruses, 329.

Wandering spiders, 88.

Warblers, 285.

Wasps, 30, 33, 43; social, 33.

Water-dog, 257.

Water moccasin, 279.

Water scavengers, 60.

Water snakes, 271.

Water strider, 12.

Weasels, 328.

Weevils, 57.

Whales, 324; feeding habits of, 325.

AVhippoorwill, 303.

Whirligig, 60.

White ants, 11.

White-breasted nuthatch, 287.

Whitenshes, 234, 253.

White-lined horse-fly, 66.

White-throated sparrow, 285.

Wingless birds, 307.

Wingless cockroach, 8.

Wood-borers, 41.

412

ZOOLOGY

Woodchuck, 320.
Wood frog, 266.
Woodpeckers, 301.
Wood-tortoise, 276.
Wood-thrush, 286.
Wood- warblers, 287.
Worms, tube-forming, 102.
Wrens, 287.

Xylotropidae, 23, 41.

Yellow bird, 285.
Yellow warbler, 288.
Yoldia, 187, 188.

Zebra, 327.

Zebra swallow-tail, 18.
Zygsenidae, 41.
Zygodactyla, 212.

A TEXT-BOOK OF ZOOLOGY

T. JEFFERY PARKER, D.Sc., F.R.S.

Professor of Biology in University of Otago, Dunedin, N.Z.

AND

WILLIAM A. HASWELL, M.A., D.Sc., F.R.S.

Professor of Biology in the University of Sydney, N.S.W.

In two volumes, containing many illustrations

Cloth. 8vo. 2 vols. $9.OO, net

"The book deserves a warm welcome, and . . . will be found an
•nvaluable aid not only to students of zoology, but also to a large num-
.jer of those whose main interest lies in other branches of scientific
study. Written with a clearness, accuracy, and method of a practised
teacher, it is admirably illustrated with a profusion of figures — there
are nearly twelve hundred in all — of the highest excellence."

— Science.

"This work, the significance and usefulness of which must be un-
qualifiedly conceded, represents an enormous amount of labor upon
the part of two experienced teachers. Nor would we underrate the
admirable mechanical features of the work and the educational por-
tent of the issue of so large and costly a text-book upon a single
branch of natural history. The intent and method of the authors are
clearly set forth in the preface. After a general introduction and a
section upon ' General Structure and Physiology,' there are presented
in turn the twelve phylums recognized, viz. : Protozoa, Porifera, Ccelen-
terata, Platyhelminths, Nemathefcninths, Trochelminths, Molluscoida,
Echinodermata, Annulata, Arthropoda, Mollusca, and (occupying the
whole of the second volume) Chordata, corresponding nearly with
Vertebrates. The discussion of each class is based upon a more or less
detailed account of the anatomy and development of one or more
forms, fairly representative and commonly available. The second
olume also contains a discussion of the mutual relationships of the
Chordata and of the twelve phyla. The last seventy pages are devoted
to Geographic Distribution, the Philosophy and History of Zoology,
\nd Modern Literature ; seven of the sixty writers recommended being
American." — The Nation.

THE MACMILLAN COMPANY

NEW YORK CHICAGO BOSTON SAN FRANCISCO

EXPERIMENTAL MORPHOLOGY

CHARLES BENEDICT DAVENPORT, Ph.D.

Instructor in Zoology in Harvard University

PART I.

Effects of Chemical and
Physical Agents upon
the Protoplasm

Cloth. 8vo. $2.6O, net

PART II.

Effects of Chemical an'
Physical Agents upo
Growth

Cloth. 8vo. $2.OO, net

"The material which is discussed has been well digest-
and is well arranged, and the style is on the whole clear a
concise. The book is a readable one, and the descriptions ah
criticisms of the methods employed in experimentation, and t:
bibliographical lists at the conclusion of each chapter, cc
tribute materially to the value the book possesses for both tl
morphologist and the physiologist." -Science.

"In this second instalment of his valuable treatise, D
Davenport considers the effects of chemical and physical ager
on growth. Plants lend themselves so readily to observatio
respecting growth that they have received from Dr. Davenpo.
a degree of attention in this work which compels the stude'
of plant physiology to accept his aid. On the whole, the ec1
torial work has been wonderfully well done, and the errors a,
so few that they need not be mentioned here ; they do r
appear likely to mislead seriously any students who make u
of the vast amount of material which has been gatheh
patiently, and for the most part has been well arranged."

— American Journal of Scienc

THE MACMILLAN COMPANY

NEW YORK CHICAGO BOSTON SAN FRANCISC

Internet Archive Audio

Featured

Top

Images

Featured

Top

Software

Featured

Top

Books

Featured

Top

Video

Featured

Top

Mobile Apps

Browser Extensions

Archive-It Subscription

Save Page Now

Full text of "Introduction to zoology; a guide to the study of animals, for the use of secondary schools;"

See other formats