i

PUTNAM'S
NATURE FIELD BOOKS

Companion books to this one

Mathews American Wild Flowers

American Trees and Shrubs

Wild Birds and their Music
Durand Wild Flowers in Homes and Gardens

My Wild Flower Garden

Common Ferns

Insects

Rocks and Minerals

Birds of the Pacific Coast

Western Wild Flowers

Birds of the Ocean

North American Mammals

Common Mushrooms

Birds of the Panama Canal Zone

Seashore Life

Marine Fishes of Atlantic Coast

Ponds and Streams

Rocky Mountain Trees and Shrubs

Lutz

Loomis

Eliot

Armstrong

Alexander

Anthony

Thomas

Sturgis

Miner

Breder

Morgan

Longyear

'^Icott 1
Putnam J

Field Book of the Skies

Each in One Volume

fully illustrated

including many

Colored

Plates

PLATE I

j^nm^M*r

wc~'?**?r;*=;snu.L vm m

r^

A !

\

PI. I. — Winter life in a brook; a section through swift flow-
ing shallows. I, stonefly, TcBniopteryx; 2, water cress; 3, alga;
4, sponge gemmules; 5, caddis worm; 6, caddis worm, Hydro-
psyche {Macronema); 7, planarian, Dendroccelum: 8, cranefly
larva; 9, water penny; 10, Corydalis larva; 11, dusky sala-
mander.

rfTiiKnri:^ no I toe?- b :vlooirf p. rr\ .,Vrf ^^ ^1^177 — x M

■ : ,-f-

A.

FIELD BOOK OF

PONDS AND stream:

(SKn Introduction to the
Life of ^resh IjOater

ANN HAVEN MORGAN, Ph.D.

PROFESSOR OF ZOOLOGY, MOUNT HOLYOKE COLLEGE

^ith about 330 Jllustradons, including 23 plates
in color and black and white

G. P. PUTNAM'S SONJ

NEW YORK — LONDON
1930

FIELD BOOK OF
PONDS AND STREAMS

Copyright, 1930

by

Ann Haven Morgan

Published, Spring, 193O
First Edition

All rights reserved. This book, or parts thereof, must
not be reproduced in any form without permission.

Made in the United States of America

To
ELIZABETH ADAMS

PROFESSOR OF ZOOLOGY

IN

MOUNT HOLYOKE COLLEGE

FOREWORD

Minnows and frogs and brown water beetles, scurrying to
cover as we approach the shore of a still clear pond, show us
that the water has some very lively inhabitants. They swim
and dive and paddle in the open until we come, and then they
hide from us distrustfully. Theirs is another world than ours.
In that world there are strange living creatures in endless
variety. There are big and little, swift and slow, strong and
weak, graceful and ungainly: all are bom to feed and grow and
reproduce, to hunt and be hunted, to strive for a livelihood;
and in so doing to fill a place in the household of nature-.

No one who has lived by clear waters can have failed to see
something of their wonderful life: minnows on the shoals;
caddis worms dragging their cumbersome portable houses over
the brook bed ; the young of mayflies clinging to the stones in
the riffle, or the adult mayflies in their dancing nuptial flight in
the air above the stream; and what could be more interesting?

To make the knowledge of the whole range of life in ponds
and streams a little more easy of access is a major purpose of
this book. And with that knowledge will come appreciation,
and a purpose to aid in keeping the waters free from pollution.
Clean waters are always charming ; and nothing is more sordid
and unwholesome than polluted water. Here is a public ser-
vice of no small moment. It is all in the interest of a better
human environment; better for health, for recreation, for
instruction, and for aesthetic pleasures.

A book like this cannot fail to render good service since it
tells the simple truth about aquatic creatures in an interesting

•V

FOREWORD

way, illustrates them with good figures, and so enables the
reader to know what they are like and where to go to find

them.

JAMES G. NEEDHAM.

Cornell University, March, 1930.

VI

PREFACE

This book began in ponds where frogs sat on the lily -pads
and by swift brooks from which mayflies flew forth at twi-
light. It originated where water plants and animals live and I
hope that it may be a guide into the vividness and variety of
their ways. Most of all I hope that it may help toward wider
enjoyment and fiirther acquaintance in the field of water
biology that offers abundant opportunity to all explorers,
both beginners and seasoned investigators.

The work of making it has been done along a trail of friendli-
ness which will not be forgotten. Those who need a way to
discover the loyalty and generosity of human nature should
write a book about ponds and streams.

I have borrowed freely from the writings of many biologists ;
some of these are named in the bibliography but lack of space
has excluded others whose contributions have not been small.
A few figures have also been borrowed and these are acknow-
ledged separately. Dr. J. G. Needham of Cornell University
first showed me how to look for things in the water; since that
time he has continually given me help and encouragement for
finding more. It is a satisfaction to have his foreword here.
Mrs. Margaret Tucker Saunders has read all of the manu-
script and has given freely of her own clear cut observations,
and her first hand knowledge of animals.

Fresh water life is a vast subject and even the simplest
account of it must include much which can be mastered only
by specialists after years of study. Many who are authori-
ties in their fields have helped generously, by giving sugges-

vu

PREFACE

tions and reading sections of the manuscript. The entire
chapter on insects has been read by Dr. C. P. Alexander of
Massachusetts Agricultural College; the mollusks by Dr. F.
C. Baker, and the worms and sponges by Dr. F. M. Smith,
both of the University of Illinois; the Trichoptera by Dr. C.
Betten, the crustaceans by Dr. G. C. Embody, the Coleoptera
by Dr. W. T. M. Forbes, the amphibians and reptiles by Dr.
A. H. Wright and Mrs. Anna Allen Wright, all of Cornell
University; the bryozoans by Dr. C. B. Davenport of the
Carnegie Institution; the Hemiptera by Dr. H. B. Hungerford
of the University of Kansas; the leeches by Dr. J. P. IVIoore of
the University of Pennsylvania; the plants by Dr. F. D. Reed
of Mount Holyoke College ; sections on water environment by
Dr. F. A. Saunders of Harvard University. Special thanks
are due to Professor S. H. Gage of Cornell University whose
comradeship in finding the facts has done much to make the
way to them straight and cheering.

Those familiar with days of college teaching know that
there is not much spare time in them. Time to write this
book has been largely made possible by my colleagues in the
department of zoology at Mount Holyoke College, especially
Dr. A. Elizabeth Adams, Dr. Christianna Smith, Bemice
Maclean, Kathryn Stein, and Margaret Grierson, who have
given me every kind of help. As my special helper in this
work, Margaret Grierson has continually contributed her un-
tiring interest and keen insight. And the mainspring of
this as of most of the activities of this department has been
the enthusiasm of Dr. Cornelia M. Clapp.

Some of the drawings have been made by the author
but most of them have been made under her direction by
Miss Grierson; Miss L. Krause at Yale University; Mrs.
E. L. Beutenmuller at the American Museum of Nattiral
History; Mrs. E. L. Burckmyer and Mr. V. S. L, Pate at
Cornell University. I appreciate the accuracy and skill with
which they have done their work. I extend my thanks to

• • «

vm

PREFACE

Mrs. Elsie Broughton Klots who selected the specimens of
insects loaned to me by Cornell University, and helped in
directing the drawings that were made there. I am grateftil
also to Miss Clara M. LeVene and Miss Vera A. Timm, of
New Haven, who have read all of the proof.

The mistakes that may be discovered in this book are in no
way the fault of those who have read the manuscript. I can
only hope that if they occur they may not be too confusing and
that they may be reported and finally eliminated.

ANN H. MORGANo

Mount Holyoke College, March, "1930.

IX

CONTENTS

PAGE

Foreword v

Preface vii

CHAPTER

I. — Water Plants and Animals and How They

Live. ....... 3

Table of plants and animals herein described.
— Water and living things — Water en-
vironment— Temperature of the water —
Food content — Light.

II. — Life in Ponds and Streams . . .11

Kinds of ponds — Balance of life in the pond —
Life in lakes — Life in slow streams and
marshes — Life in rapids and waterfalls.

III. — Collecting and Preserving Water Ani-
mals ....... 26

Collecting tools — Where and how to collect —
In ponds — In streams — When to collect —
Time of day and seasons — Care of living
animals — Cages — Aquaria and vivaria —
Preserving and mounting specimens

IV. — Simpler Plants and Animals ... 46

Algse — Blue-green and green algae — Desmids
— Diatoms — Stoneworts — Protozoans.

V. — Higher Plants 58

Water liverworts and mosses — Common water
seed plants and their animal associates.

xi

3

5103

CONTENTS

CHAPTER PAGE

VI. — Sponges (Porifera) . . . . .104

Form and habits — Habitat and seasons —

Associates — A winter study of living
sponges.

VIL— The Hydras, Fresh Water Jellyfishes

{Coslenterata) . . . • • .112

Form and habits — Habitat — Food — Associates
— Collecting and aquarium study — Common
kinds.

VIII. — Free-Living Flatworms (Planaria) . .119
Planarians and their habits — Habitat — Aqua-
rium study — Common forms.

IX. — Wheel Animalcules {Rotifera) . .127

Rotifer structures — Habits — Resistance to
cold and drought— Typical forms.

X. — Bryozoans (Bryozoa or Polyzoa) . . . 131

Form and habits — Collecting — Common
forms.

XI. — Threadworms (Nematoda) and Bristle-
worms ipiigochceta) . . . -139
Threadworms — Hair snakes — Bristle worms —
Habits and food.

XII. — Leeches (Hirudinea) . . . . .148
Form and habits — Leech bites — Food — Col-
lecting— Common forms.

XIII. — Crustaceans (Crustacea) . . . -158
Form and habits of crustaceans in general —
Classification— General description — The
smaller crustaceans, fairy shrimps, water-
fieas, copepods, ostracods — The larger crus-
taceans, scuds, isopods, crayfishes.

XIV. — Water-Mites (Hydracarina) . . .175
Form and kinship to spiders — Habits and
habitat — Common forms.

xii

CONTENTS

CHAPTER PAGE

XV. — Aquatic Insects (Ltsecta) . . . .179

Structure of insects — How insects grow — Key
to orders of insects — -Springtails {Collembola)
— Stoneflies {Plecoptera) — Mayflies (Ephe-
merida) — Dragonflies and Damselflies (Odo-
nata) — Water-bugs {Hemiptera) — Alderflies,
dobsons, and Fish-flies (Neuroptera) — Cad-
dis flies {Trichoptera) — Moths {Lepidoptera)
— Beetles (Coleoptera) — Flies (Diptera).

XVI. — Snails and Mussels (Mollusca) . .301

Habits and importance — Snails, form and
habits — Eggs — Common species — Mussels,
form and habits — Eggs and young — Com-
mon species.

XVII. — Lampreys and Fishes .... 324

Form and habits — Breeding habits — Lamp-
reys— Common brook and pond fishes.

XVIII. — Salamanders, Frogs, and Toads, Found in

OR Near Water (Amphibia) . . . 347

Form and habits — Food — Breeding habits
and life history — Common salamanders,
frogs, and toads.

XIX. — Turtles and Snakes, Found in or Near

Water {Reptilia) ..... 389

Form and habits — Breeding habits — Common
water turtles and snakes.

Bibliography ...... 407

Glossary ..,.,. 425

Index . . . . s s . 431

xm

The following illustrations a~e reprinted by permission from Fresh
Water Biology by Ward and Whipple, published by John Wiley and Sons,
Inc.:

p. fig. fig.

127 100 959. .. .Philodina, (after Weber)

872. . . .Diglena, (after Dixon-Nuttall)
893. . . .Euchanlis, (after Weber)

129 102 948. . . . Melicerta, (after Hudson and

Gosse)

143 no 836. . . .Paragordius varius, (after Stiles,

and I, 2, orig.)

838. . . .Gordius villotti, (after Mont-
gomery)

176 135 1322. . . . Limnochares, (modified from Pier-

sig)

177 136 1323. . . .Eylais (modified from Piersig)

178 137 1324. .. .Hydrachna (modified from Piersig)

ILLUSTRATIONS
Photographs, from life, by the author

PLATE PAGE

I. — Winter Life in a Brook. {In color)

Frontispiece

II. — Slow Meadow Streams and Pond Shallows 14

III. — Rapid Streams in Winter and Summer . 24

IV. — Minute Plants and Animals of Pond
Water, (/w color. Photo, by courtesy of
R. W. Miner, Am. Mus. Nat. History) . 52

V. — Pickerel- Weeds, Pontederia cordata . . 86

VI. — Fresh Water Sponge Colonies . . .106

VII. — Colony of Bryozoan, Plumatella; Proto-
zoans, Vorticella . . . . .136

VIII. — Insect Structures; Gill of Mayfly,

Water-Penny • . . . .184

IX. — Wing-Pad of a Mayfly Nymph ; Air-Tubes
of a Dragonfly Nymph, its Respiratory
System . . . . . . .186

X. — Summer Life in the Quiet Shallows of

Ponds. (In color) .... 192

XI. — Mayflies: Calliboetis, the Winged Insect
Just Emerged from Water; Blasturus,
Adult and its Cast Skin , . . 200

XII. — Egg-Clusters of a Swift-Water Mayfly,

Bcetis. ....... 202

XIII. — Burrowing Insects, Mayfly Nymphs Ephe-
mera and Hexagenia and their Burrows . 206

% XV

ILLUSTRATIONS

PLATE PAGE

XIV. — Clambering and Running Insects, Mayfly

Nymphs Ephemerella, Ameletus, Tricorythus,
CcBtiis, Siphlurus . . . . .210

XV. — Clinging Insects of the Swift Currents,

Heptagenia, Iron, Epeorus . . .212

XVI. — Collecting Nets Spun by the Caddis Worm,

Hydropsyche ...... 252

XVII. — Eggs of Water Insects: Mayfly, Horse-

Fly, Caddis Fly, and Hydrophilid Beetle 276

XVIII. — Brook Stickleback, Eucalia inconstans, and
Common Sunfish, Eupomotis gihhosus. {In
color) ....... 340

XIX. — Salamanders: Spotted Newt, Triturus vir-
idescens; Two-Lined, Eurycea hislineata;
Dusky, Desmognathus fusca; Spotted, Am-
hystoma maculatum. (In color) . . 354

XX. — Amphibian Eggs: Spotted Salamander, Am-
hystoma maculatum; Wood Frog, Rana syl-
vatica; Common Toad, Bufo americanus . 384

XXL — Frogs: S?ring Peeper, Hyla crucifer; Tree
Toad, Hyla versicolor; Green Frog, Rana
clamitans. {In color) . . . . 386

XXII. — Musk Turtle, Stenotherus odoratus. {In

color) ....... 396

XXIII. — Common Pond Turtles: Spotted, Clemmys
guttata; P.\inted, Chrysemys picta. {In
color) ....... 400

XVI

FIELD BOOK OF
PONDS AND STREAMS

/.

CHAPTER I

WATER PLANTS AND ANIMALS AND HOW THEY

LIVE

This book tells something about the common plants and
animals of fresh water and the places where they live. It
tries to show them in their home brooks and ponds and in
their native mud.

Different waters hold their own special communities; the
dainty glen stream shelters companies of mayflies in its swift
riffles; pond shallows and meadow brooks are the homes of
lurking dragonfly nymphs; and wayside puddles are popu-
lous with mosquito wrigglers and water-fleas. In all these
places living things must contend with winter cold and sum-
mer drought, with storms and flood waters. In winter the
pond populations drop to the bottom, frogs and turtles dig
under mud and broken plants, whirligig beetles hide under
banks to come out with every warm spell,-, and fresh water
sponges are packed in tough covered capsules. In summer
when its own pool dries up the water boatman flies to some
other pond but many caddis worms burrow into the mud bot-
tom and endure the drought as best they can.

How to use this book. — The table on pages 4-6 shows
the groups of plants and animals discussed in the chapters of
this book. The pictures show some of their representative
members and the brief notes beneath tell something character-
istic of them. After an animal is located in one of these groups

3

FIELD BOOK OF PONDS AWD STREAMS

it can then be followed to the chapter where it is described
more particularly. Only common names are used here; later,
common and Latin names are both given. Following the ta-
ble is a discussion of water as a home, a chapter on the com-
munity life in water and another chapter on how to find water
animals.

miM

Fig. I. — Most of these ani-
mals I -celled and microscopic
or nearly so. A. — Plant-like,
single cells or chains of cells,
often in conspicuous green
masses; B. — Microscopic, i-
celled animals.

Simpler plants and animals
(p. 46).

Fig. 2. — Typical plants
with roots, leaves, and flowers
often minute, sometimes con-
spicuous. Submerged in the
water, floating on the surface
or rising above it.

Higher plants (p. 58).

*'Vt%

^r>-'>ji

'-iSi.i

Fig. 3. — Flattened green or
yellowish masses (animal) on
submerged stones, sticks and
plants. 1-6 inches across.

Sponges (p. 104).

Fig. 4. — Thread-like, white
or green animals hanging
from sticks and stones in
quiet water. About one-
quarter inch long.

Hydras (p. 112).

WATER PLANTS AND ANIMALS

Fig. 5.— Soft, grayish or
black worms. Creeping on
under sides of stones. Gen-
erally less than one-quarter

inch long.

Free-living flat worms (p.

119).

Fig. 6. — ^Microscopic ani-
mals on stones and plant
stems or swimming near the

Wheel animalcules (roti-
fers) (p. 127).

Fig. 7. — Colonies of ani-
mals, vine-like on under sides
of stones, or rug-like beneath
lily pads, or masses of jelly
hanging in open water. Col-
onies one-half inch across
up to 15 inches thick.

Moss animalcules (bryo-

zoans) (p. 131)-

Fig. 8.— Transparent
worms, one-half inch long or
less; swarming over muddy
bottoms; red worms up to
1-2 inches long, and hair-like
worms 1-2 feet long.

Threadworms and bristle-
worms (p. 139)-

^f^S^K^

_^^^^^^^^S3B^ \f^

Fig. 9. — Flattened, worm-
like animals with a sucker at
each end. Clinging to stones
and sticks, often on legs of
turtles. Mostly 1-3 inches
long.

Leeches (p. 140)-

Fig. 10. — Many -30 in ted

animals breathing by blood-
gills; (a) microscopic, (b) i
inch, or (c) several inches

long. ^ . , .

Water-fleas, fairy shrimps,
crayfishes, etc. (crustaceans)
(p. '158).

FIELD BOOK OF PONDS AND STREAMS

Fig. II. — Brightly colored,
red, orange, spider-like ani-
mals running over submerged
plants and on the bottom.

Water-mites (p. 175).

Fig. 12. — Jointed animals
of many shapes and sizes,
most of them with 6 legs on
the thorax even in their im-
mature stages. Young and
adult often very different.

Water insects (p. 179).

Fig. 13. — Animals of many
sizes bearing a shell, i -piece
and twisted, or 2-piece and
hinged.

Snails and mussels (p. 301).

Fig. 14. — Back-boned ani-
mals with fins supported by
jointed rods of cartilage;
breathing by blood-gills
throughout their lives. Usu-
ally scaly.

Fishes (p. 324).

Fig. 15. — Back-boned ani-
mals with limbs provided
with fingers and toes; soft,
skinned without scales ; young
breathe by gills, adults have
lungs.

Salamanders, frogs, toads

(p. 347).

Fig. 16. — Back-boned ani-
mals with scaly skin, often
covered with bony plates;
breathe by lungs throughout
their lives.

Turtles and snakes (p. 389) .

WATER PLANTS AND ANIMALS

Water and living things. — Plants and animals grow in every
brook and pond. The first ones lived in the water and their
descendants still dwell there in great beauty and abundance.
Water still offers protection and support, and in it plants
and animals can secure a livelihood on easier terms than they
can on land. Many of them have lived in the water ever
since their ancestors started there; others, the aquatic seed
plants and insects, tried living on land but went back to the
water. Diverse histories lie behind the varied company of
plants and animals which now make up aquatic society, but
they have all become more or less adjusted to their common
experience of water life.

Water environment. — Water is all around us. It covers
more than two-thirds of the earth's surface; ocean or streams
and lakes and little ponds are almost everywhere. Water
has more properties which are beneficial to living things than
has any other substance. It is seven hundred and seventy
times heavier than air, with a surface film upon which spring-
tails can jump, and water striders can walk. This surface
film is stronger than that of any other fluid except mercury-;
and although the water strider's feet bend it down into six
dimples, they do not break it. Snails and planarians glide
over its underside, and hydras hang head downward from it.
The little crustaceans, Scapholeberis (Fig. 124), cling to it, ven-
tral side up. On this side they are darkly colored, while their
backs are pale, their coloring like their position being just the
opposite of that in most animals. The larvae of mosquitoes
thrust their airtubes through the surface film and rest there,
tails up and heads down. Like the larvcc of the big diving
beetles (Fig. 209), and the pond scorpion, and many others,
they are buoyed up by their own air supply.

The greater density of water gives it more supporting
power than air, so much so that the fairy shrimp (Fig, 123)
and a host of other animals can float motionless in it. All
types of animals and many plants have relied upon its sup-

7

FIELD BOOK OF PONDS AND STREAMS

port; in water, even the heavy claws of the crayfish take on
a Hghtsome poise (Fig. 133). It is a good transporting agent,
too, and even clear riffle- water carries a load of minute organ-
isms on which the net-building caddis worm depends for food
(PI. XVI).

Temperature of the water. — Water is safe to live in, summer
and winter, for it does not get so hot nor so cold as air. It
is a poor conductor of heat and the changes which occur in
a pond are far more gradual than the sudden shifts in the air
above it. Ponds have fairly equable temperatures even
though they be located in temperamental New England. In
general the temperature of the water determines the level
which it will occupy in the pond. Cold waters tend to drop
to the bottom and warm waters rise to the top, shifts of
great import to the hosts of little plants and animals which
they carry along with them. As the pond surface cools in
summer evenings the top waters fall a little, and when it
chills in autumn they drop farther, taking myriads of little
organisms downward to winter safety. Water is heaviest
when it has cooled to 39.2° F. (4°C.), and then it gradually
forms a bottom layer. If the surface water grows colder
than that, it becomes less dense, lighter in weight, and stays
in the upper levels. At 32° F. (o°C.) it freezes, the ice floats,
and the pond is covered with a blanket which keeps its warmth
from radiating into the colder air above it. In small ponds
spring sunshine melts the ice and gradually warms the water
through, even in the bottom layers. In large lakes there
is a complicated spring overturn and circulation of the water
due partly to changes in temperature and partly to the action
of the winds which blow across the surface.

Food content of the water. — The final food supplies of all
water organisms are the non-living substances in the water.
These are dissolved gases, oxygen and carbon dioxide, and
the raw materials of foods, such as carbonic acid and salts —
phosphates, silica, calcium carbonate, and nitrates. Their

8

WATER PLANTS AND ANIMALS

proportions vary in different waters and under diverse condi-
tions. Water absorbs oxygen from the air so that near the
surface it is more abundant than in the lower layers. Proof
of this can be seen in any bowl of goldfish. Whenever their
water supply becomes low in oxygen the fish swim about
near the top where there is more of it to be found than in the
lower levels.

In their respiration, green plant cells take in oxygen and
give off carbon dioxide, just as animals do. But in photosyn-
thesis or food making they take in carbon dioxide and give
off oxygen. Photosynthesis can go on only in the light and
during the daytime this process is so vigorous that its results
overshadow those of respiration. Thus during the day the
net result of both processes is that plants give off some car-
bon dioxide but much more oxygen than they take in, while
at night, when respiration alone continues, they give off
carbon dioxide only. At night the little crustaceans which
live below the surface waters come up to the top to breathe
the abundant oxygen which they find there as a result of the
day's plant activity, and at the same time they give off carbon
dioxide which will be used by the green plant cells next day.

The amount of the carbon dioxide in water is greater in
winter than it is in summer, because plants are at a lower
ebb of life and do not use so much of it. But spring sunshine
starts them into greater activity, which results not only in
their increased demand for carbon dioxid-e, but in the pro-
duction of oxygen at a period when the animals will need it.

Light in the water. — Water is transparent, but it is well known
that even the clearest water is far less transparent than air.
It lets the sunshine in upon green plants which can prepare
their own food from non-living materials only when they
have enough of it. The vast hosts of diatoms and desmids,
other simple plants, and even many of the higher ones, could
not live on pond and stream bottoms as they do if light did
not penetrate through many feet of water. Studies of the

9

FIELD BOOK OF PONDS AND STREAMS

distribution of algae in clear, deep lakes have shown that they
cannot get light enough except in the upper fifty or sixty
feet of water, and even in the lower levels of that they are
very rare. The main population of green plants and animals
lives only where light is abundant. Consequently shallow
ponds are inhabited down to the bottom, but in large, deep
lakes life extends through only a small proportion of the
depths.

10

CHAPTER II

LIFE IN PONDS AND STREAMS

Ponds. — Small bodies of water are sometimes called ponds
and the large ones lakes, but properly speaking a pond as
here considered is a body of water which is so shallow that
rooted water plants can grow all the way across it. It may
be a half mile wide; but it is usually not more than twelve
or fifteen feet deep, often less than that. Its waters are so
shallow that the bottom is well lighted except where the sur-
face is covered by lily pads and duckweeds; but even in such
places plenty of light sifts down upon the growing organisms
below. Such ponds warm through quickly; an unusually
warm winter's day will bring the whirligig beetles up to the
surface, and a week or two of spring sunshine will set the
whole pond astir. Water and such abundant light and
warmth are the only essentials for the growth of diatoms,
desmids, and filamentous algse — the great plant crop of the
water, the food supply for millions of small animals which in
their turn become food for larger ones like the fishes.

Kinds of ponds. — Many ponds which teemed with life in
late winter and spring are dried up and dead looking by
August. These transient ponds depend upon the rainfall
and the drainage from surrounding hills. They are~ the
uncertain ones in which the fairy shrimps appear, and a host
of other little crustaceans which can endure months of drought
in their "resting egg" stages, insects like caddis larvae which
dig down into the bottom mud, and water-bugs which can

II

FIELD BOOK OF PONDS AND STREAMS

fly to some other place as their own pond dries away. Frogs
lay their eggs by thousands in these short-lived ponds and
the early summer droughts turn such places into tadpole
cemeteries.

Permanent ponds are the ones w^hich hold the greatest
variety of water life. They may be big or little, spring-fed
or stream-fed, low in the marsh or high on the upland, in
the woods or the open; if they only offer water the year
round they can support a large population.

Life in ponds (Fig. 17). — In nearly all ponds certain plants
grow in more or less clearly defined zones and particular
communities of animals are associated with them.

Fig. 1 7. — Diagram of the distribution of pond plants.
In the background are the emergent water plants —
I, pickerel weed; 2, cat-tails; 3, bulrush; 4, bm-reed; 5,
water plantain; 6, arrowhead. In the foreground
are the floating-leaved plants — 7, Polygonum; 8, lily
pads; 9, spatter-docks; 10, hornwort; 11, eelgrass; 12,
pond weed; and the submerged plants — 13, Riccia; 14,
bladderwort; 15, water milfoil.

Closest to shore are the emergent water plants, those which
grow with their roots in the water and their stems and leaves

12

LIFE IN PONDS AND STREAMS

in air. Among them are reeds, bulrushes, and marsh grasses,
the white-blossomed arrowheads, water plantains, the massed
blue spikes of the pickerel weeds, and crowding into every
space high standing-armies of cat-tails (Fig. 17). Covering
their stems below the water line are the simpler plants,
desmids and other algae, on which swarms of small crusta-
ceans feed. Little plant-eating worms are abundant on them,
also, and some of the smaller water beetles.

Beyond this zone are the floating-leaved plants, growing
in water knee-deep or a little more. There, the bottom is

Fig. 18. — Diagram showing the population on the
undersides of lily pads: i, bryozoan colony; 2, midge
larva; 3, snail's eggs (Physa); 4, beetle's eggs (Dona-
cia); 5, snail (Grauhis); 6, snail (Physa); 7, eggs of
caddis fly {Tricenodes); 8, water-mite; 9, tubes of
midge larvae; 10, eggs of water-mite; 11, eggs of
damselfly (Enallagma); 12, tube of rotifer (Melicerta);
13, sponge; 14, eggs of whirligig beetle.

soft and pleasant to walk through and the mud boils up
through it with every step one takes. Near shore, lily pads
and the ever-present little duckweeds lie on the surface
and leaves of the yellow spatterdocks are only half lifted

13

PL II. — I. In the slow meadow streams are diving beetles,
nymphs of dragonflies and damselflies, burrowing mayflies,
water striders, tadpoles, and leopard and green frogs along
the banks. 2. Pond shallows; near shore duckweeds cover the
water like a blanket and dot the water surface beyond; here
the lily pads are floating hatcheries for the eggs of snails and
water insects; sunfishes and sticklebacks hide below them.

Photo, by A. H. Morgan

PLATE II

f^-^^a^--^'^

LIFE IN PONDS AND STREAMS

from it. Sometimes it is gay with the rose-colored flowers
of Polygonum amphibium (Fig. 73). In the deeper water,
the ribbony leaves of pond weeds and fresh water eelgrass
stream upward from the bottom. There also may be the
submerged meadows of homwort and just below the surface
the little vine-like liverworts, Riccia (Fig. 52), and the blad-
derworts, Utricularia (Fig. 82).

Fig. 19. — Bottom-dwellers: i, mayfly (CcBnis); 2,
tubes of Tubifex; 3, worm (Nais) ; 4, dragonfly {Li-
bellula) .

The animals which live near shore are even more varied
and more numerous than the plants. On the underside of
a single lily pad (Fig. 18) are snails, small red water-mites,
tube-dwelling rotifers of the genus Melicerta (Fig. 10^), and
numerous midge larvag. These same lily pa,ds are so many
hundreds of floating hatcheries for the eggs of snails, mites,
beetles, and other water insects. All the plant stems are
coated with a green slime of algae, the food of pond-snails
and countless numbers of little tube-dwelling worms. Colo-
nies of fresh water sponges and bryozoans encircle the stems
and spread over the under surfaces of leaves. One sweep
of the net will bring up insect carnivores — larvae of tiger-
beetles, water-bugs, dragonfly and damselfly nymphs.

15

FIELD BOOK OF PONDS AND STREAMS

Plant-feeding nymphs of the mayfly Callibcetis (Fig, 158)
dart through the open water. Many of the population have
taken to the bottom and when a netful of mud is scooped up
or a handful drained through one's fingers, its inhabitants be-
gin to appear — mayfly nymphs, little red worms (Tubifex)
(Fig. 114), and dozens of other pale worms (Nais) (Fig. iii),
and midge larvas, each one squirming enough to be finally
discovered. They all find food in this mud mainly from
the diatoms with which it is saturated.

Fig. 20. — Typical plants and animals of plank-
ton society. A. Plants — diatoms: i, Fragillaria; 2,
Asterionella; — desmids: 3, Cosmariuni; 4, Stauras-
trum. B. Animals — protozoans: ^, Arcella; — rotifers:
6, Notholca; — crustaceans: 7, Cyclops.

Most small ponds are so shallow that water-lilies and
pondweeds grow even in the deepest places. The surface
waters of the larger ponds and lakes are occupied by a float-
ing population known as plankton, made up of millions of
microscopic plants and animals (Fig. 20). The plant cells
are mainly diatoms and desmids, so translucent and minute
that thousands of them would go unseen in a glass of drink-
ing water. There are a few kinds of one-celled animals or
protozoans, many rotifers, and swarms of diatom-eating

16

LIFE IN PONDS AND STREAMS

crustaceans, the females of the latter often bearing their egg
sacs with them. The number of different plankton organisms
rises and falls during the year; many species have seasons of
special abundance. Cyclops (Fig. 126) may predominate at
one time, and some other crustacean at another time, their
abundance paralleling the increase of one or more diatoms
which are their natiiral food. Plankton organisms have an
enormous reproductive capacity. This is especially true of
diatoms, which form a staple food crop of the water, compara-
ble to the grass crop on land.

Larger animals of the pond. — Among the lily pads and the
water weeds of the shallows, lurk sunfishes, bullheads, mud
minnows, and young perch. All of these forage upon snails,
crustaceans, and insect larvae, especially the tempting mayfly
nymphs which they find there. Bullfrogs float with their heads
just out of water; of all frogs these belong most thoroughly
in the pond. Equally at home in it are the painted turtles,
and the spotted turtles often found with them (PI. XXIII). In
May and June stumps and floating logs usually carry a load
of one kind or the other. They forage in the shallows taking
a heavy toll of tadpoles, snails, dragonflies — a miscellaneous
bill-of-fare which they always eat under water. Snapping
turtles frequent these waters also, catching anything with-
in reach of the lightning-quick thrusts of their heads — fishes,
tadpoles, frogs, or crayfishes, as well as the smaller game of
insects and worms.

Balance of life in the pond (Fig. 21). — In a pond everything
alive is good eating, and even dead and broken fragments do
not go unrelished. Swarming millions of tiny crustaceans
feed upon the algae; young fishes devour the crustaceans;
and older fishes, turtles, frogs, and even dragonfly nymphs
prey upon young fishes. Midge larvae and mayfly nymphs
consume the plant tissues, living and dead; larger insects
eat the little wormlike midges; and later, tiger beetles and
larger dragonflies feast upon their insect relatives, only to

17

FIELD BOOK OF PONDS AND STREAMS

be swallowed in turn by fishes and the other larger water
animals.

In a particular year many or very few individuals of a
species may be found but seldom does any one species entire-
ly die out. At one time nymphs of dragonflies may dominate
the water while mayflies may be hard to find ; yet by another

Fig. 21. — Food relations in the pond where large
animals eat the smaller ones: i, adult fish; 2, swarm-
ing crustaceans; 3, young fishes; 4, frog; 5, snail; 6,
dragonfly nymph; 7, midge larvae; 8, mayfly nymph;
9, tadpole; 10, painted turtle; 11, young frog.

season mayflies may be gathered with every scoop of the net.
In one way or another the balance of life is maintained.
Dragonfly nymphs can clutch and bite while mayfly nymphs
can do neither; yet mayflies make up for their lack of weapons
by their ability to live upon plant food which they can find
almost anywhere and by the great number of young which
they produce. Some of the pond mayflies like CallilxEtis
(Fig. 158) lay eggs when they are less than six weeks old,
so that there is time for three or four generations of them to

18

LIFE IN PONDS AND STREAMS

mature and reproduce in one summer. A single female may
lay a thousand or more eggs, and as Needham has pointed
out, by the fourth generation the possible offspring may num-
ber one hundred and twenty-five billions. Even this record
hardly equals that of the army of minute crustaceans. These
are eaten by many carnivores, yet they have overtopping
advantages. Their minute size and their transparency are
protections, and like mayflies they feed on plants and have
a great reproductive capacity. It has been calculated that
in sixty days there might be thirteen billion descendants
from one female Daphnia pulex (Fig. 124) if no accident
befell any of them.

Life in lakes. — Lakes are but larger editions of ponds. In
the protected shallows of both, the communities are almost
alike. But on the open lake surface where the wind blows
unhindered, it sweeps water against the shores. There,
clinging forms are found: snails, net-building caddis worms,
and at a depth of three feet or more the large burrowing may-
fly nymphs. Ephemera and Hexagenia (PI. XIII), whose
cast skins are often washed up into windrows upon the beaches.

In lakes there are great areas of deep, open water where
there are no hiding places for small animals like those pro-
vided by the trash and vegetation in shallow waters. But
the lake surfa.ce harbors a great floating or plankton popu-
lation, sometimes miles of it, billions of microscopic animals
and plants which are not only constantly increasing but also
constantly being eaten, or dying and dropping to the bottom.
Fishes also live in the open usually a few feet below the sur-
face. They are not minute or transparent like the plankton
but the}'- are swifter and stronger than any other water
animals. They stay near the top where the foraging is
good, though in large lakes this means ten or fifteen feet
beneath the surface. Below this depth there is a lonesome
reach of water, generally barren of plant and animal life.
And finally beneath this is the deep soft ooze of the barely

19

FIELD BOOK OF PONDS AND STREAMS

lighted bottom which mud dredgings show to be but sparsely
inhabited by a few small worms, mussels, and little red midge
larvae.

In spite of their size large streams do not harbor so many
nor such interesting forms as the smaller ones; this is equally
true of large rivers as compared with small ones. Rivers
travel far, often through soft soil, and their waters gather
sand and silt only to drop them again along the way, smother-
ing fragile plants and animals beneath them. Only in sluggish
rivers or in the inlets of swift streams is there much shore
vegetation where the smaller clamberers can hide. With
all its uncertainties in drought and flood time, the small
stream still has greater advantages, for it is well lighted even
on the bottom, and its waters are generally free from mud.

Fig. 22. — Diagram showing the distribution of ani-
mals across a slow stream. Plants — i, arrowhead; 2,
spatterdock. Animals — 3, dragonfly nymph; 4, tube
of midge larva; 5, tube of bloodworm; 6, mud-leech;
7, scud; 8, burrowing mayfly, Hexagenia; 9, white
clam; 10, whirligig beetle; 11, water boatman; 12,
water strider; 13, mayfly, Callibcetis; 14, caddis worm;
15, snail.

■ Slow streams and marshes (Fig. 22). — A slow stream flows
gently and steadily over flat land; its bottom is of fine mud,
sometimes of sand; there are no rocks, it has no waterfalls or
rapids, and its waters are generally free from mud. Now and
then there are inlets crowded with cat-tails, reeds, pickerel
weed, and in some regions with Vv'ater-hyacinth (PI. II).

20

LIFE IN PONDS AND STREAMS

Its animal population is very much like that of ponds, es-
pecially if higher plants grow along its banks. Where the
bottom is sandy there are burrowing mayflies, mussels, snails,
and the big dragonfly nymph Cordulegaster which lies with
its hairy body buried in the sand. In the stretches of muddy
bottom are leeches, mussels, and, if the mud is firm enough,
little white clams of the family Sphceridce (Fig. 266). There
are innumerable midge larv^, a few of the never-failing

Pj(, 23 —Diagram of the distribution of animals
in a waterfall. The stones A, B and C are shown
enlarged, with their inhabitants; A and C are right
side up ; B is wrong side up. i , egg masses of midges; 2,
water moss, Fontinalis; 3, midge larvae; 4, alga, Clado-
phora; 5, mayfly, Chirotenetes; 6, nets of caddis worm,
Hydropsyche; 7, Pupa cases of caddis worm, Helico-
psyche; 8, 9, mayflies, Heptagenia and Epeorus; 10,
planarian; 11, caddis worm; 12, water penny; 13.
leech; 14. stonefly nymph; 15, caddis worm; 16,
black fly, Simulium.

21

FIELD BOOK OF PONDS AND STREAMS

crustacean genus, Asellus (Fig. 131), and as in the ponds,
there are plenty of back swimmers and water boatmen.

Life in the rapids (Fig. 23). — In rapids the water is always
falling and jostling, and every plant and animal must con-
stantly clamber, or cling, or glue itself to some holdfast. Water
pushes against the flattened stones tilting them so that even
when it is all dried out of the stream, they still tell which way
the current ran.

Fig. 24. — Collecting basket of the mayfly, CJiiro-
tenetes.

The green and golden-green films of desmids and diatoms
upon the stones, the green tufts of such algse as Cladophora
(Fig. 23), and the green- black water moss Fontinalis (Fig. 55)
are among the scanty plant population of the rapids. Of the
larger animals there are a few fishes, minnows and darters,
and agile two-lined salamanders which skulk under the stones.
Immature insects predominate — midges, stonefiies, caddis
flies, and mayflies, along with leeches, planarians, and a few
snails.

Nearly all of these animals of the rapids live upon micro-
scopic food. Net-building caddis worms (Hydropsyche)
strain their food from the water in their cup-shaped nets
which open upstream (PI. XVI). The mayfly Chirotenetes
(Fig. 24) carries its own collecting basket to catch plankton
from the current. Facing upstream with tail and rear legs

22

LIFE IN PONDS AND STREAMS

firmly braced, it holds its hairy front legs close beneath its
bewhiskered mouth-parts and stands ready for whatever
food the water may bring to it.

Attached to the rocks by a sucker on the hind end of the
body, larvae of the black fly Simulium (Fig. 233) swing out
into the water, spreading their fan-shaped food-brushes to
sweep the diatoms and floating algae into their mouths. If
its end sucker loses hold the larva is washed downstream;
but even then if it can only get its mouth in contact with
a stone or stick it will use some of its silk-like saliva to tie
itself down again, swinging upon this till it can once more
anchor its sucker.

Fig. 25. — Epeorus, a mayfly of the rapids, and its
mouth parts showing their diatom rakes: i, nymph;
2, right and left upper jaws or mandibles; 3, right
and left lower jaws or maxillae; 4, tongue; 5, lower lip
or labium.

Planarians, snails, and most of the mayflies suck or rake
and scrape the green algal slime from the stones and like
sheep in a pasture they can get their mouths close down to
the smallest growths. The planarian actually swings its
sucking proboscis out from the center of its body (Fig. 93) ;
but the mouths of mayflies are beneath their flattened heads
and are similarly effective (Fig. 25). Mayflies of the rapids
like Heptagenia, Epeorus and Iron, have horny teeth and

23

PI. III. — I. In running water some animals are active

all winter; insects, snails, and planarians creep over the stones

and salamanders skulk beneath them. 2. Insects emerge

from the rapids by hundreds, and the fly-catching phoebes

take a plentiful harvest from the air; in the jostling water

small animals find safety by holding on or getting under

cover.

Photo, by A. H. Morgan

PLATE III

LIFE IN PONDS AND STREAMS

combs on their mouth-parts and using these as diatom rakeS
they can pull in a good harvest.

Amid the jostling water of rapids small animals find safety
only by holding on, by getting under cover, or by being small
or slender or flat (PI. III). Flattest of any of this society
are the water pennies (Fig. 215) which cling motionless to
the under surface of the rocks, smooth-backed and copper-
colored, looking like small pennies but not at all like the
young beetles that they really are.

Waterfalls. — In springtime the rocks of waterfalls are green
with algae, but later the water mosses Fontinalis and Hygro-
hypnum often crowd in and cover them. These grow on the
straight rock face, well under the waterfall, escaping the dash
of the water but kept wet by constant tricklings. Here
small clamberers hide among the leaves — case-bearing caddis
worms and beetle and midge larvae. Midges swarm above
the falls and lay their eggs in little white skeins upon the
wet rock. Adult midges emerge from the waterfalls by
hundreds, and the fly-catching phoebe on the branch above
gets a plentiful harvest from the air. Large falls are forag-
ing places for swallows which collect the emerging mayflies;
even at Niagara they swing into the mist and spray, and
when they dart out again their mouths are whiskered with
protruding mayflies.

25

CHAPTER III

COLLECTING AND PRESERVING WATER ANIMALS

Collecting tools (Fig. 26). — For the smaller water animals,
crustaceans, insects, and the like, the important collecting tools
are a water-net, a white pie plate or saucer, a pair of forceps,
a hand-lens, a pail with a cover which fits over the outside,
and a few bottles. The water-net should be about eight inches
in diameter with a stiff rim to hold the shallow bobbinet bag
and a handle not over three feet long. Such nets are sold
by supply dealers, or may be made at home. The rim should
be so rigid that it will not bend and twist in the handle when
the net is pulled through weeds and muck. A strong frame
for a water-net can be made as shown in Figure 26, i and 2.
Two grooves are made at one end of the handle (Fig. 26, 2) ;
one groove is about four inches long and the one opposite is
an inch longer. A small hole is bored into the handle at the
end of each groove. The heavy wire for the frame is bent
as shown in the figure (Fig. 26, 2), and the ends of the wire
are fitted down into holes and along the grooves. The whole
end is then bound tightly with fine, strong wire or heavy cord.
The efficiency of the net depends upon the rigidity of the frame
and the tightness of the binding. The net itself should be
made of strong bobbinet fastened to tough cotton cloth cover-
ing the rim. A pie pan or any shallow white dish holding a
little water makes a good background for the field examination
of snails, leeches, dragonfly nymphs, and the like, while they

26

PRESERVING WATER ANIMALS

6

s

U 0

zp-

Fig. 26. — Collecting equipment: i, water-net; 2,
method of fastening wire to handle; 3, hand-lens; 4,
forceps; 5, a, shell and b, homeopathic vial; 6, knap^
sack; 7, data label to be put into vial; 8, white pie pai-
for examining living animals.

27

FIELD BOOK OF PONDS AND STREAMS

are fresh from the pond and more beautiful than they may
ever be again. A few vials of alcohol (p. 27) should be taken
along to hold the small, fragile forms which must be preserved
at once. A canvas knapsack is almost indispensable but its
size and the arrangement of pockets depend upon its uses and
the collector's own taste. It is essential to have a pocket
note-book so that observations may be written down on the
spot.

3 '^■'^^^iw

Fig. 27. — Collecting bags and jar: A, open bag; B,
bag tied for frogs; C, bag tied for snakes; D, Mason
jar used for frogs' eggs.

For carr^'ing larger animals, like frogs and turtles and snakes,
stout cotton bags are most convenient (Fig. 27) ; those about
six inches wide and ten inches long are handy sizes but larger
ones are desirable for the bigger or fiercer game. The tie-
string should be sewed on so that it will always be ready
when needed. Covered Mason fruit jars (Fig. 27, D) are use-
ful for carrying frogs' eggs in water but they should be uncov-
ered as soon as possible after one reaches home with them.

There are a few other necessary tools. An air-net (Fig.
28) is essential for capturing flying insects and a killing bottle
for insects (Fig. 28) which are to be preserved dr>\ The air-
net is made like the water-net except that its bag is deep and
its frame is about a foot in diameter. For killing bottles
both potassium cyanide and carbona are used, the former

28

PRESERVING WATER ANIMALS

almost altogether by entomologists. Insects dropped into
either of these bottles soon die from the fumes. It is general-
ly advisable to secure cyanide bottles from dealers rather
than to prepare them at home since potassium cyanide is a

Fig. 28. — I, Killing bottle for insects; 2, air-net;
3, wire sieve-net for pulling up mud and trash.

deadly poison and should be handled with extreme caution.
They should always be kept tightly stoppered in order to
conserve their deadly fumes for the insects. A few drops of
carbona or carbon tetrachloride sprinkled on cotton and put
into a tight bottle will kill insects satisfactorily and yet may
be safely handled. It usually has to be renewed at each
collecting trip but carbona bottles can be made in such a
way that they will last much longer. Soak some pieces of
old rubber overshoe or inner tube in carbona; put these in a
bottle with absorbent cotton packed around them and a
piece of cardboard to hold them all down.

29

FIELD BOOK OF PONDS AND STREAMS

Forceps about twelve inches long are almost indispensable
for reaching into the water in winter collecting, although
many things can be hand picked on the undersides of stones,
pulled out of riffles and over-turned upon the bank. Al-
though not essential, a sieve- or trash-net (Fig. 28) is some-
times useful when muck must be ladled up to the bank or
into a boat. Sieve-nets can be purchased from dealers; the
small' ones are best, less than a foot square and two or th^'^.e
inches deep.

Fig. 29. — Glass-bottomed bucket pressed down into
the riffles to avoid the distortion at the surface and
make the bottom visible.

A wooden bucket with a plate glass bottom (Fig. 29) helps
one to see the bottom of shallow rapids. It is simply pressed
down into the water so that one can look through it and avoid
the distortions made by the uneven surface water. Other
useful tools are the cheap wire "lifters" made by soldering
a wire to a square of window-screening and used to lift animals
from aquaria, hand-bulbs and pipettes or medicine-droppers
for picking out frogs' eggs, and a little aquarium net (Fig. 30).

Where and how to collect. — Near the edge of the pond in.
summer, look for flowering plants, bulrushes, reeds, water
snakes, bullfrogs and green frogs, tadpoles, water-mites:,

30

PRESERVING WATER ANIMALS

swarms of springtails, insect larvae and nymphs, especially
those almost ready to leave the water.

Collect with a water-net. For insects and all smaller
animals skim the net through the water, scraping it against
the vegetation, but do not scoop into the bottom.

Fig. 30. — Aquarium tools: I, pipette for picking
out frogs' eggs; 2, hand-bulb; 3, wire lifter; 4, aqua-
rium net.

hi the shallows. — In the zone of floating leaves are water-
lilies, pondweeds, the stoneworts — Chara and Nitella —
water-fern worts, duckweeds, and the liverwort Riccia; algae
grow on the submerged stems and "blanket-algae" on quiet
water surfaces (PI. X). The larger animals common there
are the spotted turtles, bullfrogs and green frogs, perch,
catfishes, pickerel, and several kinds of young fishes; the
smaller animals include all types of water insects, bryozoans,
snails, leeches, and small crustaceans.

31

FIELD BOOK OF PONDS AND STREAMS

Collect with a water-net, sweeping it through the water
and brushing the submerged vegetation. Turn the lily pads
for snails, sponges, bryozoans, and insect eggs. Almost any
of the plants harbor snails and little crustaceans.

Fig. 31. — Collecting with a plankton-net: i, skim-
ming the surface; 2, draining off the extra water; 3,
pouring plankton out of the net; 4, plankton organ- '
isms after settling.

In the surface water. — In the open surface water of ponds
and lakes are the plankton or microscopic plants and animals
— desmids, diatoms, blue-green algas, protozoans, crustaceans
adult and young, and rotifers (PI. IV).

To collect plankton near shore or in the smaller ponds
skim the surface with a long-handled, cone-shaped, plankton-
net made of silk bolting cloth, trailing the net through the
water (Fig. 31,1) preferably from a boat. After a few minutes'
continuous skimming, let the net drain until only a cup or
so of water remains, then loose the string letting this through
the open end (Fig. 31, 3). Such skimming should be repeat-

32

PRESERVING WATER ANIMALS

ed several times. If plankton organisms are abundant they
will settle to the bottom of the dish as a brownish or greenish
sediment (Fig. 31, 4).

The bottom. — On the pond bottom, in the mud or sand, are
mussels, crayfish (in limy regions), an occasional turtle, mud-
loving dragonfly nymphs, small mayflies like Ccenis and
Tricorythus, big burrowing ones — Ephemera, Hexagenia — and
a host of midge larvse and small worms such as Tubifex (Fig.
32).

Fig. 32. — A netful of mud with its inhabitants: i,
Ccenis; 2, Tuhifex; 3, worm, Nais; 4, Tricorythzis; 5,
mud-tubes of midges; 6, nematode worm; 7, snail.

Scoop up the mud and trash in small lots with a strong-
rimmed water-net. Let the load drain till the animals begin
to clamber; then pick them out and drop them in a white
dish for examination (p. 27).

Slow streams. — The population of small coves and the
side waters of streams is similar to that near the pond shore
(PL II). Scoop and sweep with a water-net as in the ponds
but work upstream so the current may take away the muddy
water.

Riffles and rapids. — Algas and water mosses on the stones

33

FIELD BOOK OF PONDS AND STREAMS

are the only plant growths. The animals stay on the under
surfaces of the stones, hiding beneath them, or on their lee
sides. Among them are a few small fishes — darters and
minnows — two-lined salamanders, flattened mayfly and stone-
fly nymphs, net-building caddis fly larvse, "water pennies,"
Simulium larvae, leeches, planarians, and the swift-water
snails — Ancylus and Goniohasis.

Work upstream. Pull stones from the water, turning them
over quickly before the stonefly nymphs drop off; examine
them carefully, since many of the animals cling tightly and
are the same color as the stone. Hold the net against the
current, stirring up the stones and gravel above it so that the
animals which are dislodged will be caught in it.

Waterfalls. — Water mosses, Hygrohypnum and Fontinalis,
are apt to grow here and clambering animals hide among
them — larvae of caddis flies and the cranefly Dicranomyia,
crustaceans lilce Gammarus and Asellus, small mayfly nymphs
and many midge larvae.

Clear pools, — In gently flowing streams, usually in their
clear pools, are beds of little white mussels of the genus
Splicer ium. Asellus is common in tiiem and nymphs of the
dragonfly, Cordulegaster.

Leaf -harriers. — Leaves and trash catch in the riffles form-
ing leaf-barriers which hold their own distinct societies
wherein the crustaceans — Asellus and Gammarus — are prom-
inent, and the largest of the cranefly larvae, Tipula ahdomina-
lis.

Springs. — Green algae spread over spring pools and form
"blanket algae" communities (p. 50). These are populated
by minute forms — diatoms, desmids, protozoans, worms,
rotifers, crustaceans, and midge larvae.

On land, hy ponds and streams. — IMany kinds of animals
leave the water but stay in the regions near it. Frogs forage
among the grasses, along the banks; salamanders hide beneath
stones on the wet shores or in drier places nearby. Adults

34

PRESERVING WATER ANIMALS

of aquatic insects skulk in the shrubbery, or swarm above
the water, and mayflies and caddis flies can often be found
in the spider webs on bridges where they have been caught
in flight.

Electric lights. — Electric street lamps and the lighted win-
dows near streams or lakes are gathering places for insects,
especially on warm humid nights; then caddis flies and
craneflies may be picked by dozens from the electric light
poles or from the sides of buildings.

When to collect. Weather. — In the brook, there is no closed
season; even in January the flat stones of the rapids shelter
a lively multitude. Sunshiny days are the best ones even
for water collecting. Spring sunshine brings out the turtles
and all the tadpole tribe, toad, frog, and salamander, and
insect visitors crowd into the blossoms of the white water-
lilies. Dragonflies and their kin emerge from the water;
unlike their dusk-loving relatives the little Leptophlebias
(mayfly) swarm forth on quiet sunny afternoons. On misty
days or in soft rains flying insects hide under bridges, beneath
leaves, or on nearby tree trunks and can be easily picked
up by hand.

Time of day. — Many things can be found only at special
times, in the morning, or at twilight or night. Mating
flights of mayflies and caddis flies occur in late afternoon,
mostly at twilight. Animals which hide in the daytime are
usually most active at night; such are the mqsquitoes, moths,
crayfishes, salamanders like Ambystoma, the toads, and
several of the frogs.

Many water animals lay their eggs at definite times, some-
times almost by the clock. Snapping turtles lay eggs in
the forenoon, wood turtles lay in mid-afternoon, and spotted
salamanders at night.

Seasons. — In the water as in other places, spring and
summer are in general the most active and most populous
times. Water organisms join others in the winter retreat

35

FIELD BOOK OF PONDS AND STREAMS

to cover; but some of them are easily stirred from their
hibernation and others are active all winter (PI. I). The
following list suggests a few of the things which can be found
in open spring-fed brooks or beneath pondice.

In ponds and slow streams
October — November

Salamanders ( Triturus)

(P- 353)
Bullfrogs and green frogs

(p. 385)
Water boatmen, backswim-

mers (pp. 237, 239)

CrayjEishes carrying their

eggs (p. 172)

Nymphs of dragonfiies and

damselflies, abundant

(p. 214)
Whirligig beetles (p. 271)

In rapids
January — February

Green alg£e (p. 49)

Protozoans ( Vorticella)

(p. 57)
Sponges (gemmules) (p, 104)

Bryozoans (statoblasts)

(P- 131)
Planarians (p. 119)

Snails (p. 304)

Mussels with young in their

gill pouches (p. 318)

Young insects, net-building

caddis worms (p. 251)

Care of living animals, life-history cages. — The way to learn
most about animals is to watch them in their own homes or
to keep them in cages which allow them to behave some-
thing like themselves. Such are the life-history cages within
which insect nymphs may be kept in their own brooks. The
simplest of these rearing cages (Fig. 33), one devised by
Dr. J. G. Needham, is made from a piece of wire window-
screening measuring about eighteen inches square. The
ends are brought together and hemmed over to form a
seven inch cylinder. The ends of this are then flattened
and hemmed and the cage is pillowed out to give comfortable
space within. One end can be easily opened when insects
are placed within the cage. In order to secure the different
stages of the life-history of water insects like dragonfiies or
mayflies, capture fully grown nymphs recognizable by their
black or very large wing-pads and put them in rearing cages
set a couple of inches down into the water of the insects'
home stream. Put only one kind of insect in at a time and

36

PRESERVING WATER ANIMALS

fasten a tag to the cage, writing name or number with the
date, and keep a note-book record of them. Make the cage

-^

1

Pjc. 33.— Cage for rearing water insects: i, cylinder
of wire window-screening with hem; 2, finished cage
with ends folded, detail of hem. (After Needham.)

safe from floods and plunder; visit it every day or two if
possible. The winged insect should soon be found at the
top of the cage with its cast skin clinging to the cage side
below. The cast off skin and the winged insect should be
preserved in alcohol as a record of its immature and adult
stages. Many quiet- water insects can be kept for a few days^
in screen-covered dishes within doors and their changes from'
nymph to adult go on equally well there.

Aquaria.— Put a layer of sand in a tumbler, plant a branch
or two of Elodea in it, fill the glass with water from the pond
and then let it settle. Put a couple of pond snails into it—
and the aquarium is complete-made simply enough, yet
here a snail can live through a sample of its normal daily life

37

FIELD BOOK OF PONDS AND STREAMS

(Fig. 34, 2). The life-history of mosquitoes, larva, pupa
and adult (Fig. 34, i), can be watched in such a simple aqua-
rium; only this one should be kept covered.

Fig. 34. — Aquaria in tumblers: i, Ciilex mosquitoes,
showing one larva and two pupae with their air-tubes
thrust through the surface film, floating eggs, adults;
2, snails and Elodea.

The balanced aquarium (Fig. 35) is just what its name
says — a balance between plants and animals. The plants
use the carbon dioxide produced by the animals; the animals
use the oxygen given off b}'' the plants. A good aquarium
plant is one which affords a bountiful supply of oxygen.

The best aquarium dishes are rectangular glass ones which
are as wide as they are high. Cylindrical ones distort the
vision; deep ones shut out the air so that the water gets little
oxygen. In making a balanced aquarium spread a layer of
mud over the bottom, being sure that it is free from car-
nivorous animals; cover this with a layer of sand and gravel.

38

PRESERVING WATER ANIMALS

Water plants should be set in this, good ones for the aquarium
being Elodea, AlynopJiyllum, and wild celery or Vallisfieria
(^ig- 35) • The water should be added gently and then

Fig. 35. — A balanced aquarium showing: i, Elodea;
2, Myriophyllum; 3, Vallisneria; 4, mayfly nymph; 5,
adult mayfly; 5a, cast nymphal skin of mayfly; 6, tad-
pole; 7, snail; 8, snail's eggs seen through reading
glass.

left to settle for a couple of days. Many things will live well
in such an aquarium if they have plenty "of oxygen and a
little food. Snails will lay their eggs on the sides of the jar;
such pond mayflies as CallihcBtis and Blasturus, and dragon-
flies and tadpoles will thrive here. Do not crowd the ani-
mals and do not mix the vegetarians and the carnivores;
after such a mixture there will be only one kind left.

It is better to have several small aquaria (e.g., 6x3x5

inches) than one large one.
If aquaria are made of plate glass, things can be photo-

39

FIELD BOOK OF PONDS AND STREAMS

graphed through the sides. A reading glass is useful

for observing the very small animals.
If the glass sides and the water become green, it means

that too many algae are growing there. The aquarium

should have less light, or there should be more snails

to eat the algae.
If the gill-bearing animals keep going to the surface, they

need more oxygen; there are too many animals and

not enough plants. One small aquarium will support

only a few animals.
Scum and bubbles on the top usually mean decaying

material below. A greasy scum forming on the water

very soon after it is put into the dish is a sign that it

has been treated with alum.

Vivaria. — Salamanders and frogs live well in terraria.
There are many ways of arranging these so that the animals
have water accessible and yet can climb out on the moist
earth. In making these as in making aquaria the best way
is to copy a small section of the animals' own home.

Preserving specimens. — There are special methods by which
plant and animal specimens of different groups are best
preserved. These are suggested in discussions of several
different groups in this book, and are fully described in books
and papers listed in the Bibliography (p. 408). Animals are
generally preserved in alcohol or formalin, or by drying.
Books which give directions for preserving plants are listed
in the Bibliography.

Killing animals. — Insects such as adult dragonflies and
moths should be killed in a cyanide bottle or with carbona
(p. 29) ; but aquatic larvae and nymphs and many other
small forms are best killed by dropping them directly into
alcohol.

Fish, frogs, salamanders and the like should be chloro-
formed or killed by other methods which common sense may

40

PRESERVING WATER ANIMALS

suggest. If chloroformed they should be enclosed in a tight
pail with a little chloroform sprinkled on a cloth.

Occasionally it may be desirable to use chloretone, though
not often. This is an anaesthetic which will kill small water
animals painlessly and leaves them relaxed and ready to be
put into alcohol or formalin. It is sold in crystals which
can be dissolved in water to make a saturated solution.
Such a stock solution should be kept on hand and a little of
it used as needed. The animal should be placed in a little
water and drops of chloretone added until it is entirely
inert.

Fig, 36. — Specimen vials and rack for holding them.

Preserving insects and other anitnals. — Alcohol (ethyl 95%)
diluted with about one-fourth water is the best general pre-
servative for sponges, worms, leeches, crustaceans, water-
mites, soft-bodied insects, frogs and salamanders and tad-
poles, and for mollusks if the soft parts are to be kept. But
alcohol is expensive and difficult to secure; and though
nothing else is so satisfactory for insects, formalin is much
cheaper and often better for other things,- especially larger
animals like crayfishes, frogs, and turtles. In these a slit
should be made in the abdominal wall to let the preservative
in upon the viscera. Eggs and larvae of frogs and other
amphibians keep well in a weak formalin solution. Formalin
is sold at almost any drugstore and is not expensive; the
proper solution may be made by adding one ounce of com-
mercial (40%) formalin to sixteen ounces of water.

Storing specimens in alcohol (Fig. 36). — Small specimens
are best kept in well-corked vials. There are several types

41

FIELD BOOK OF PONDS AND STREAMS

of vial racks, most of them planned for storage on trays or
shelves of closets. Each bottle should have a label giving
the name or number of the specimens, the place and the date
where they were caught, and the collector's name. These
data may be written on regular labels or in soft pencil on a
slip of paper placed inside the vial with the writing turned
toward the glass; larger animals should have similar labels
of heavy paper tied to them.

Some specimens are much better preserved by drying;
such are the adult dragonflies, beetles and the like which
can be stored: i, in cotton; 2, in "papers"; 3, mounted on
pins; or 4, arranged in "Riker boxes."

I. — Layers of cotton are useful for temporary storage of
large lots of adult insects, especially those which have been
caught at one time or place. Fit a layer of glazed cotton
into a tin box, spread a layer of insects on it, then put in an-
other layer of glazed cotton. When the specimens are packed
put the cover on tightly to keep out the insect-eating pests;
label with the date and place of collection.

Fig. 37. — Successive steps in folding a storage
envelope for insects.

2. — Storage envelopes (Fig. 37) or "papers" are made by
folding pieces of paper of about postcard size. One or more
specimens are inclosed within these and the data written on
the outside. Insects stored like this may be "relaxed"
(p. 43) and mounted at any time; the envelopes should be
kept in tightly closed pest-proof boxes.

3- — Mounting on pins (Fig. 38) is such a common method

42

PRESERVING WATER ANIMALS

of displaying insects that it should be mentioned here. If
the insects have become dried they should be put into a
relaxing jar and left there over-night before the mounting
process is begun. The relaxing jar may be almost any kind
of large covered jar with a layer of damp sand in it overlaid
with clean paper. After insects have lain in such a damp
jar for a day or two their legs and wings can be moved easily

Fig. 38. — Insects mounted on pins: i, with pin
through the thorax; 2, beetle with pin through the
right wing; 3, same in side view with label.

and they are ready for the mounting process. A special in-
sect pin is put through the middle of the thorax or if the
specimen is a beetle, through the right wing, and the legs are
carefully extended.

If the insect has long wings like a damselfly it should be dried
with wings outspread (Fig. 39); and a spreading board must
be used. The simplest kind is made of soft wood with a row

Fig. 39. — Spreading board with damselfly spread
upon it, dorsal side down.

43

FIELD BOOK OF PONDS AND STREAMS

of gimlet holes down the center, each about half an inch deep.
The specimen is pinned in the regular way and then placed
dorsal side down on the board with the head of the pin reach-
ing to the bottom of one of the holes. The wings are carefully
outstretched with a piece of paper pinned across each one, and
the specimen is then left in a safe place to dry.

NeT-s|3inn'ma lory©
Of C acid is uioi^rn

r^iF^

Li|e» HisTori-j c^ ttie, CoJjis -flu Vlt|droJ36i(che.

Htidi'of^ot^che

ioYA/ac- yrvoh

s- n©Ts

o^ s'lih-lihe sail

oa. in

U)V»'

cK t^«c^

Catch IKeir +

oo<j

l-rom

Tke

sTrenm.

Met of l-lu3n>t£i^cVie

Cadoi& j-lu ea^ on iwia

Streamy Slooi SJtreamj "R^nos Streams Streams
Cases maje \f\ diffcreoT s|?cci«.a o^ Ca<lo ' o uxwm 6

Fig. 40. — A " Riker box " showing how caddis flies
may be mounted to show their habits and life history.

4. — " Riker boxes" are shallow boxes with glass covers (Fig.
40). They ma}- be made by hand but it is generally more
economical to purchase them ready for use from supply dealers.
Each box is fitted with a layer of glazed cotton upon which
specimens can be arranged together with whatever descriptions
are to be included. After specimens and labels are in position
the glass cover is pressed close down over them and carefully
sealed on with binding tape, or some other fastening, which
will make the box pest-proof. Specimens in "Riker boxes"

44

PRESERVING WATER ANIMALS

can be easily examined, handled without fear of breaking and
they may be made reasonably safe from insect-eating pests.
Groups of specimens with a few explanatory labels thus pre-
sent good accounts of the habits and life histories of many
small animals.

45

CHAPTER IV

SIMPLER PLANTS AND ANIMALS

Algae and Protozoans

Water teems with plants and animals invisible to the naked
eye but being microscopic they are outside the general
scope of this book. Yet it is upon these organisms that the
whole aquatic population ultimately depends for its food ; and
in a few cases at least one needs no microscope to detect them,
for they collect in masses that are conspicuous by their color
or odor. Brook beds and water weeds are golden brown with
millions of diatoms; the familiar " pond-scum," "green-scum,"
and the "water-bloom" of ponds and lakes, are made up of
microscopic algas. Certain algse make reser\^oir water taste
fishy or bitter or make it smell like cucumbers. Pale whitish
spots on water-washed stones and fuzzy patches on the legs
and backs of water insects are actually colonies of one-celled
animals, the beautiful bell-shaped protozoans, Vorticella and
Epistylis (Fig. 51).

Algse. — Fresh water algas are simple plants whose form
varies from minute rods, stars, crescents, richly patterned mi-
croscopic ribbons, slender filaments, single or branched, to the
stoneworts (p. 53), so simply built that they are often classed
with algae, yet so large and so much branched that they look
like the higher plants. The filamentous algas grow in long
threads or filaments, formed of narrow cells, attached to each
other end to end, tandem- wise (Fig. 48). Sometimes these

46

SIMPLER PLANTS AND ANIMALS

filaments are branched, forming a tuft attached to stones, but
they have no structure comparable to a root. Many algse
are single-celled ; such are the desmids and diatoms although
the constriction around the center of desmids makes them look
two-celled, and many diatom cells cling together in spherical
and ribbonlike colonies. Marine algas such as the familiar
seaweeds are conspicuously red or purplish or brown; but ex-
cept for the diatoms most of the fresh-water algae are green or
blue-green. In all alg£e the cells contain chlorophyll, the green
substance by which plants are able to prepare their own food
out of the raw materials of non-living matter. In green algae
masses of chlorophyll are naked within the cells displaying the
characteristic green color, but in the diatoms the chlorophyll
is cloaked with yellowish-brown diatomin, which gives diatoms
their typical color. Fresh water algas grow in untold numbers
in running streams of every description, in lakes, ponds, and
pools, and in every little place which holds a few days' stand
of soft water.

Six classes of algas are commonly recognized. They are
known chiefly by their colors, red or brown, or green; these
colors except in the green algae are due to coloring matter
which covers the green chlorophyll. Two of these classes are
predominantly marine, and the members of one, the yellow-
green algae, are not common or conspicuous enough to be de-
scribed here.

1. Blue-green; filamentous algae, Cyanophycece. Alostly
in fresh water.

2. Green; filamentous algas, desmids, stoneworts, Chlo-
rophycecB. In fresh and salt water.

3. Yellow-green; Bacillariacece. Mostly in fresh water.

4. Diatoms, Diatomacece. In fresh and salt water.

5. Brown; brown seaweeds, PhceophycecB. Mostly in
salt water.

6. Red; red seaweeds, Rhodophycece. Mostly in salt
water.

47'

FIELD BOOK OF PONDS AND STREAMS

Blue-green algae. — During midsummer blue-green algae
(Fig. 41) often become very abundant in lakes, especially in
reservoirs where they sometimes form the surface film known
as "water-bloom." They are microscopic, one- or many-
celled, but commonly form simple chains as in Anahcena
(Fig. 41). When light is thrown directly through them they
look blue-green, but when it merely falls upon them, as it does
in ponds, they make the water appear red or purplish. In
hot springs blue-green algae and sulphur bacteria are almost
the only living inhabitants and the blues, pinks, and yellows
of the silicious deposits around the hot springs of Yellowstone
Park are largely due to them.

Fig. 41. — Blue-green algae: i, filaments of Ana-
hcena; 2, Oscillatoria; 3, Rivularia.

Among the commonest of the blue-green algas is the free-
floating AnahcBna (Fig. 41), which forms the water-bloom on
ponds and lakes and is one of the principal foods of swimming
crustaceans. The purplish-black mats of Oscillatoria (Fig.
41) cling to the sides of ditches and pools, to rocks and to the
stone coping of reservoirs, often becoming detached and float-
ing free at the surface. Under the microscope its filaments
exhibit remarkable oscillations, twisting and writhing, coiling
and uncoiling, curving to one side and then to another. Gel-
atinous brown clumps of Rivularia (Fig. 41) are common upon
stones in rapids, on Chara, Myriophyllum, pondweeds and
broken water-soaked leaves of cat-tails, especially in the fall.

Green filamentous algae, desmids. — In early spring there is

48

SIMPLER PLANTS AND ANIMALS

scarcely a pool or runnel that is not brightened by green alg£e.
They exist in a bewildering variety of sizes and shapes. Among
them are the minute single cells of the desmids, hundreds of
species fancifully shaped like crescents and stars and triangles,
slender interlacing strands of the filamentous algae like Spi-
rogyra, and swimming colonies such as Volvox and Euglena (Fig.
44), which are animal-like save that they are green with
chlorophyll and secure their food by the plant-like method.
These organisms are all astride the border between plants and
animals. Some of them appear like plants and others more
like animals; in classifications we find some of them placed
with the algae and some with the protozoans, their presence
in one or the other group depending a good deal on whether
a botanist or a zoologist is discussing them. Desmids are
single-celled like diatoms; but a living desmid is bright green
and a living diatom is golden brown. Many desmids are con-
stricted at the center, as if the cell were partly divided; others,
for example, Closterium, have a light band across the middle.

Fig. 42. — Desmids: i, Closteriimi; 2, Micrasterias;
3, Tetmemorus.

Desmids are always present in the plankton of lakes, and
abundant in clear sunlit ponds. A glass of water from sphag-
num pools (p. 65) will often be nile green with them and
crescents of the larger species of Closterium which grow in
such places can easily be seen with a hand-lens.

49

A

FIELD BOOK OF PONDS AND STREAMS

The dense green mats of "pond-scum" or "frog-spittle"
and the "blanket algae" of early spring are filamentous algse
which grow on the surface of sunny pools and form bubbles of
gas as they decay. In such "blankets" Spirogyra (Fig. 43)
usually predominates, but the threads of Zygnema (Fig. 43)
and other forms are interlaced with it, as well as a host of
desmids, diatoms, and minute animals. In spring pools

Fig. 43. — Filamentous green alga;: i, Spirogyra; 2,

Zygnema.

"blanket algae" flourish all winter, sheltering an extensive
community of animals — small mayflies, midges, and crusta-
ceans feed on the algae and in turn furnish food for predacious
animals — young dragonfiies, beetles and the like.

The similarity between certain green algae and animals has
already been mentioned. One of the largest of these animal-
like algae is Volvox (Fig. 44, i), whose beautiful spheres of cells
are but green dots to the naked eye, though sometimes they

Fig. 44. — I, Volvox; 2, Eiiglena.

are so crowded through the water that a glass of it will be col-
ored nile green with them. There are hundreds of cells in each

50

SIMPLER PLANTS AND ANIMALS

sphere, and each one is provided with microscopic lashing
threads whose joint action turns the whole sphere over and
over in a slow swimming movement. In midsummer and
autumn a smaller green alga, Euglena (Fig. 44), covers the
surface of pasture ponds and slow streams with a vivid green
velvet-like film. Microscopic examination of the smallest
particle of this film will reveal hundreds of little whale-shaped
Euglenas, each with a flagellum waving from its front
end.

Diatoms. — Diatoms (Fig. 45) are minute single-celled plants,
estimated to be about one-thousandth of an inch thick. They
float free in the water or are attached to leaves and stems;
growing in groups or solitary and in myriad shapes and pat-
terns (PI. IV). They are the most abundant of all organisms
in both fresh and salt water. They cover the stems of sub-
merged plants, and most aquatic insects carry hundreds of
them hanging upon the hairs of their bodies. In spring they
reproduce in enormous numbers, floating upon the surfaces of
lakes and covering the stones of stream beds with a film of
golden brown.

Fig. 45. — Diatoms: i, Meridion; 2, Tabellaria.

All diatoms are enclosed in shells of silica, transparent,
colorless, finely lined and patterned. A diatom shell has two
parts or valves, the upper valve fitting over the lower one just
as a cover slips over a box. The diatoms figured are common
ones selected because they suggest the variety and beauty of
those which grow in the most ordinary pool (Figs, i and 45).

51

PI. IV. — Minute plants and animals of pond water. Photo-
graph of part of a model showing life in one-half inch of pond
water, magnified one hundred times. Model designed and di-
rected by Roy W. Aliner, in American Museum of Natural
History, i, stem and i a, traps of Utricularia (p. lOo); 2, stem
and leaves of Elodea (p. 79); 3, green algas, Spirogyra (p. 50),
and 4, ChcBtophora; ^ydesrmd, Closterium (p. 49); 6, protozoan,
Vorticella (p. 57); 7, 8, 9, 10, rotifers (p. 127); 11, entomos-
tracan (p. 161); 12, hydra (p. 112); 13, larva of midge caught
in trap (p. 291); 14, egg of water-mite; 15, dead leaf. Diatoms
and desmids project from the surface of Utricularia stem.

Courtesy of Dr. R. W. Miner

\ V

PLATE IV

SIMPLER PLANTS AND ANIMALS

Stoneworts, Family Characeae

The stoneworts are an intermediate between typical algag
and the higher plants. Their structure is simple and they
appear in man}'- ways like specialized algae; yet they look so
much like higher plants that it is difficult not to associate
them with that group. They are attached to the pond
bottom and usually grow a foot or more high in broad, water-
covered meadows. There are two common genera, Chara
(Fig. 46) and Nitella (Fig. 47); several species of Chara
secrete lime and have been named "stoneworts" because
of their hard limy surfaces.

Fig. 46. — Candelabra plant, Chara fragilis.

Chara. — Submerged gardens of Chara grow in ponds fed by
waters from limy soils; the plants are from one to two feet
high. Their slender brittle stems consist of nodes, where the

53

FIELD BOOK OF PONDS AND STREAMS

t

branches grow from the stem in whorls, and intemodes, an

inch or more between. The core of the intemode is made up

of one cell which extends the entire distance from one node to

another. Stems and branches also are single cells, but are

covered by a layer of fine cells like those which surround the

central cell of the intemode.

The fruiting organs are of singular beauty and large enough

to be clearly seen with a pocket-lens. They are borne at the

Fig. 47. — Nitella.
54

SIMPLER PLANTS AND ANIMALS

base of the branches, the pear-shaped ovary with its single
egg, and the male organ or spermary beside it looking like a
brilliantly colored, microscopic orange. In it are thousands
of sperm cells which finally break forth and make their way
to the egg. A short time after the egg is fertilized it falls from
the branch and later germinates into a new plant.

Chara plants have a marshy odor often distinctly sulphiiry
and feel harsh and brittle to one's fingers. There are many
species, but in our flora Chara fragilis (Fig. 46) is the common
one.

The limy covering of Chara stems makes them poor eating
and is an effective barrier to all sorts of herbivorous nibblers,
but vast numbers of diatoms and desmids settle on them and
these provide food for a large population of vegetarians.

Occurrence: Cosmopolitan. July-August.

Nitella. — Nitella (Fig. 47) is more delicate than Chara but is
so similar that it is often called by the same common name,
candelabra plant. Its branches grow out from the stem in
whorls like Chara, but both these and the intemodes are naked,
not covered by cells and seldom encrusted with lime as in
Chara. This gives them a translucent delicacy and easily dis-
tinguishes Nitella from its relative.

Occurrence: Nitella is cosmopolitan, but less common than
Chara. July-August.

Protozoans

A protozoan is a minute animal, living as a solitary cell,
or in groups, when they are known as colonial protozoans. All
of them are microscopic or~nearly so (Fig. i , B) ; the typical
protozoans do not collect in large masses like the algas, but a
few of them are large enough to be seen with a hand-lens.

Protozoans exist in untold numbers in both salt and fresh
waters and every pool and brook has its population of them.
A few of them are figured here. These are commonly found on

55

FIELD BOOK OF PONDS AND STREAMS

the insects or in water which has been brought in from ponds.
They are selected because either singly or in clusters they are
large enough to be seen through a hand-lens, sometimes even
with the naked eye.

Fig. 48. — Stentor.

Stentor. — These are trumpet-shaped animals which are
transparent blue-green or whitish (Fig. 48). Against a white
background the blue-green ones can be seen with the naked
eye. They are often very abundant in the water about sphag-
num moss.

MinMiiiniluill!'Wirt'[Hirilr,M_rr.;.,,,.yii.i,,,,,;)|j,^^

Fig. 49. — Spirostomum.

Spirostomum. — Spirostomum (Fig. 49) occurs in shaded,
dark-bottomed pools, each animal appearing like a white line
about the length of a dash. Large numbers of them some-
times whiten the surface of the water.

Paramoecium. — Paramoecia (Fig. 50) show only as white,
rapidly-moving particles in dishes of pond water , or as a
white edge on the water line when they are crowded together
on the surface of dishes of pond trash which have been left
standing.

Bell-animals, Vorticella, Epistylis, Carchesium. — Colonies of

56

SIMPLEU PLANTS AND ANIMALS

Fig. 50. — i,Param(scium; 2, Paramoscia along a
water line.

Vorticella or Epistylis (Fig. 51, Plate VII) make the fluffy whit-
ish patches which can be found in summer and winter on the
bodies of water-insects and crustaceans, or on submerged sticks

Fig. 51. — I, Vorticella; 2, Epistylis.

and stones. In some streams scarcely an insect will be found
which does not have a crop of these springing, bell-like animals
growing upon it. Colonies of Carchesium are common upon
the undersides of sticks and stones in streams, where they
grow nearly an eighth of an inch high.

57

CHAPTER V

HIGHER PLANTS

Water Mosses and Seed Plants

Compared with the number of higher plants which live on
land there are very few which live in the water. Most of
these bear their flowers above the surface though their leaves
and roots grow beneath it and they make up little groups
which are usually but fragments of large families that belong
on land. They live only partially in the water and are not
truly aquatic like the simpler plants.

In most ponds the rooted plants (Fig. 21) grow from the
shore out to midwater and they vary greatly in the degree to
which they have taken on the ways of aquatic life. Close
to shore the arrowheads and pickerel-weeds (PL V) stand
upright with leaves and flowers a foot or more above the water.
A little farther out are plants which lean upon the water for
support; such are the yellow water-lily and the white one,
with pads and blossoms floating on the surface. Beyond these
plants, often among them, are featherj^ milfoils, Myriophyllum
and Elodea, and streaming pondweeds, the Potamogetons, all of
them submerged except for their flowers, which open in the air
and depend upon air currents or upon flying insects or upon
water to carry their pollen. Although these plants are largely
beneath the water, their reproduction occurs in the air. The
same thing is true of mayflies and other aquatic insects ; they
live in the water for a long time but they come out in the air
to mate and lay their eggs.

58

HIGHER PLANTS

In nearly all ponds are plants which float free, entirely
unattached to the bottom; some of them are at the surface,
others just below it. They are the duckweeds, with little
dangling rootlets, the bladder worts, drifting unanchored, and,
in limy water, lush growths of horn wort.

The plants included in this book are only the commonest
ones of ponds and brooks with two or three others, like the
pitcher-plant, which grow in water-sodden bogs or marshes
and are much visited by insects. The animal associations of
each plant are briefly mentioned; such partnerships as those
of the water-lily and the beetle, Donacia, (p. 279), and trage-
dies like those continually occurring within the leaf traps of
pitcher-plants and bladderworts.

Aquatic Liverworts and Mosses — Bryophyta

The liverworts and mosses make up the group of Bryophyta,
green plants closely related~to the algse and in classifications
placed just above them. They are small, green, shade and
moisture loving plants, which grow crowded in mats and clus-
ters. Most of them live in moist places on land; there are a
few in ponds but more often they grow in running streams;
only a small number can thrive in dry places. They absorb
water rapidly but having no storage cells they quickly lose
it again. Water goes out of their cells as easily as it does
from the skins of frogs and they cannot endure dryness much
better.

Liverworts — HepaticcB

Liverworts have some traits like the alg^ but though their
ancestors may have been aquatic, they are now in general a
land group and their forms and habits suggest the mosses.
The liverwort has a green leaf-like thallus, which carries on
the main work that in flowering plants is done by leaves and
roots. If a thallus is thin, chlorophyll develops in all its cells
and both sides are green; if it is thick, only the upper surface

59

FIELD BOOK OF PONDS AND STREAMS

is green and the lower one bears root-like outgro\\i;hs. There
are but few aquatic liverworts, commonest among them being
the Riccias (Fig. 52) which grow in ponds.

1 - ^

Fig. 52. — I, Riccia natans; 2, Riccia fluitans.

Crystalworts, Riccia fluitans and Riccia natans. — These sim-
ple liverworts float free in the water or grow on the mud along
the shores of ponds or quiet streams. Riccia natans (Fig. 52)
has a lobed thallus and floats on the surface of the water like
duckweed. Riccia fluitans (Fig. 52) lies just below the sur-
face, spreading its slender branched thallus through the water
in a bright green network. It often grows among the duck-
weeds and broken bits of its thallus are often caught with
net sweepings in the shallows. In case the water in which
they are living dries away, either of these Riccias will grow
on damp soil and then the thallus is apt to be reddish or pur-
plish. Riccias thrive in aquaria and Riccia fluitans is very
often a stock plant of supply dealers.

Mosses — Musci

Mosses can live on the faces of rocks where food and water
are scarce, on decaying logs in deep woods, in marshes, and
even completely submerged in brooks and shallow ponds.
They grow crowded together like the liverworts and lichens
with which they are very commonly associated. But their
flat green leaves distinguish them from both liverworts and
lichens, neither of which bear leaves. The aquatic Riccias

60

HIGHER PLANTS

(Fig. 52) are examples of the leafless state of the liverworts.
"Reindeer moss" and the "red-tipped moss" are common
lichens having no leaves but only stubby branches colored
gray-green by algae which grow like a cloak about the white
fungus within.

!s)>or-e cq[)5u.I«-
, with cab remcved

-I-

A

' tsr s^JOTfc bearlnd

'^fe

* — 5<».»nefo J> liyfe.
or sex cell

-rl)izold

Fig. 53. — Diagrammatic outline of parts of a moss
plant.

Several kinds of mosses are more or less aquatic. The most
abundant of these are the sphagnums, bog mosses, which
thrive best when they are soaked with water. Others grow
upon the rocks in swift mountain streams and in gorges, where
they cover the stream bed with a green-black carpet.

Life history of mosses. — A "fruiting moss plant" (Fig. 53)
consists of an upright leafy stem or branch, rootlike organs or
rhizoids and a capsule of spores usually borne on a stalk.
Carried to the right place by wind or water, the spores will

6i

FIELD BOOK OF PONDS AND STREAMS

germinate into minute filaments, the protonemata, which make
little green patches upon the earth from which the familiar
moss plants ultimately grow.

Some moss plants bear female organs, the archegonia, equiv-
alent to the ovaries of an animal ; others bear male organs, the
antheridia, equivalent to spermaries. In the antheridia there
are thousands of minute male cells some of which subsequent-
ly fertilize egg-cells borne upon the female plants. The
familiar capsule of spores arises from a fertilized egg and is
always borne on a female plant. The spores from the cap-
sule mature and are scattered upon the ground and without
fusing with any other cell develop into plants which represent
the asexual generation. Each moss plant is of a different sex,
some bearing male, others bearing female organs. Such male
and female plants occur in every other generation and hence
are known as the sexual generation.

Water Mosses — FontinalacecE

The water mosses are a family of slender, very dark green
mosses with long streamer-like branches, which wave from
the stones in swift currents, or grow upon stones and wood on
the edges of ponds.

Dichelyma. — The yellowish green masses of Dichelyma
grow commonly on rotting sticks in and around the edges
of ponds and in swampy places. The plants of Dichelyma
capillaceuni (Fig. 54), our only common species, are yellow
toward the tips and brownish or black below. The stems
are slender, often over three inches long, branched, and usually
matted together. The spore capsule matures in summer, its
short stem or seta protruding from the leaves that wrap close-
ly around it.

Occurrence. — New Brunswick to Ontario and Pennsylvania.
Fruits in summer.

Fountain mosses, Fontinalis. — The fountain mosses form
dense, dark, olive green covers upon the stones of swift brooks,

62

mOHER PLANTS

Fig. 54. — I, A leafy branch of the common Diche-
lyma capillaceum; 2, leaves more enlarged. (Grout.
From Bry. Eur.)

sometimes in sluggish streams, very rarely in quiet water.
Their stems are about three inches long, irreg^ularly branched?
with slightly spreading leaves which are absent altogether
from the lower part of the stem.

The giant fountain moss, Fontinalis gigantea (Fig. 55), very
common in cool brooks, can be distinguished by its three-
cornered branches which grow several inches long. The
other species figured, F. NovcB-Anglice (Fig. 55), is probably
our commonest fountain moss.

Occurrence. — Spore capsules mature in summer but they are
rarely seen, their stems being so short that they are entirely

63

FIELD BOOK OF PONDS AND STREAMS

concealed by the leaves. Cool streams, North America and
Europe.

Fig. 55. — Branches of two common fountain
mosses: i, Fontinalis; 2, leaf arrangement of Fonti-
nalis gigantea; 3, leaf arrangement of Fontinalis
Nov(B-AngU(E. (2 and 3 from Grout.)

Hypnums — Hypnacece

Water hypnums, Hygrohypnum. — The first part of the word
Hygrohypnum, derived from the Greek, well names these
mosses " wet hypnums. " They grow in bright green or yellow
green patches on the rocks in and near the beds of swift
streams. Hygrohypnum ochraceum (Fig. 56), whose branches
are 2 to 4 inches long, larger than most of the genus, can be
found in almost any mountain brook.

Occurrence. — {H. ochraceum) — Northern and central North
America. Fruits in spring and early summer.

64

fflGHER PLANTS

Fig. 56. — I, Plant of Hygrohypnum ochraceum; 2,
leaf arrangement of same. (Grout. From Bry.
Eur.)

Sphagnums or Peat Mosses — Sphagnacece

Peat moss, Sphagnum. — The sphagnums are pale colored
green or pink tinged mosses which grow in big cushiony beds,
in bogs and marshes. These wet yielding tussocks are made
up of the long closely packed plants, their lower ends brown
and dead, their stems and rosette-like heads pale green and
leafy. This appearance results from their habit of growing
at the tips and dying off below.

Their leaves closely overlap each other (Fig. 57). Broad
spoon-shaped leaves and thick branches distinguish a num-
ber of species called the spoon-leaved peat mosses ; those with
narrow pointed leaves and slender branches are the acute-
leaved peat mosses. Separate species within these groups
are very difficult to distinguish.

All of them are remarkable for their power of absorbing
water and microscopic examination shows that certain of
their cells, narrow ones but normal in their supply of proto-
plasm, and chlorophyll, are surrounded by large thin- walled
cells which have entirely lost their protoplasm. The walls

65

FIELD BOOK OF PONDS AND STREAMS

of these cells are not only thin but are perforated with large
pores, and water can pass to and fro through them with the

^^£^

^^^

Fig. 57. — I, Leafy branches of Sphagnum, an
acute-leaved peat moss, bearing spore capsules;
2, without spores; 3, spore capsule, enlarged.

greatest ease. These colorless cells account not only for
the paleness of sphagnum mosses, but for their extraordinary
power of absorbing water. Moist sphagnum has long been
used by florists to wrap plants for shipping and during the
Great War dry sterilized sphagnum was much used as an
absorbent wound dressing.

Seed Plants — Angiosperms

The parts of the flower. — Aquatic seed plants have essen-
tially the same structure as their terrestrial relatives and many
of them thrive just as well on a damp shore as they do in the

66

HIGHER PLANTS

water. Most of them have root, stem, leaves and flowers,
which function very much as these parts do in typical land
plants (Fig. 58).

^11611 cell'

Whwoytil
pollen I0 ovule.

ovarvj

jjollen cell
■at. ro|>
&ti"dTna

stamen

se|5al

ovule (f^

jseJicel

1 ^

Fig. 58. — Diagrams of i, the parts of a leaf
(SagiUaria) ; 2, a complete flower, cut in section to
show its parts, and the pollen cells and their path-
way to the ovules.

A complete, or typical flower (Fig. 58) is made up of four
parts besides the stalk — stamens on which the fertilizing
pollen or male cells are produced; pistils which receive the
pollen cells and through which they pass down into the ovaries
where they fertilize the ovules or eggs; petals which provide
a colorful advertisement of these essential reproductive
organs; and sepals which protect and hold the other parts
together. In the differences of color and form and arrange-
ment of these four parts lies all of the beauty and variety of
flowers.

The pistil is usually in the center of the flower. Its en-
larged basal part is the ovary containing the enlarged female
reproductive cells or ovules; its tip is the stigma. Stamens
usually encircle the pistil; a stamen consists of two parts — •

67

FIELD BOOK OF PONDS AND STREAMS

the anther, which holds the pollen grains, and a stem-like
filament. Pollen grains are deposited upon the stigma of the
pistil by wind or by insects, or may simply fall upon it.
The process is known as pollination (Fig. 58). After a pollen
grain and an ovule come together, their nuclei fuse, the ovule
is fertilized and later develops into a seed.

Cat-tails — TyphacecB

Cat-tails are marsh and waterside plants, which grow 4 to
8 feet tall, with creeping root-stocks from which new plants
sprout up each spring. These root-stocks grow in all direc-
tions and in a few years each parent plant is the center of a
colony of cat-tails. Their banner-like leaves, even taller than
the flowers, are smooth olive-green, shimmering and silvery
when the wind shakes and turns them. The broad-leaved
and the narrow-leaved cat-tails are the two well known
species in the United States.

Broad-leaved cat-tail, Typha latifolia. — In the broad-leaved
cat-tail (Fig. 59) the two sections of the flower spike are close-
ly adjoining. The upper yellower half contains the male or
staminate flowers and the lower olive-green part holds the
pistillate ones. Pollen of the staminate flowers is wind-
carried from one spike to another. The flowers first appear
in June. Soon after that the staminate part of the spike
shrivels, but the pistillate half fluffs out into the familiar
chestnut -brown cat-tail head, about an inch in diameter,
which lasts all through the winter, even well into the next
spring. But toward spring it loses its trim, clipped surface,
and becomes more and more shaggy and unkempt as its
quarter million or so of seeds are gradually loosened from
the central stalk.

Occurrence. — Although both species are widely distributed,
the broad -leaved cat-tail, Typha latifolia (Fig. 59), is com-
moner than the narrow-leaved, Typha angustifolia (Fig. 60).
It is found throughout temperate North America; frequent

68

HIGHER PLANTS

Fig. 59. — Broad-leaved cat-tails, Typha lati folia:

1, flower showing staminate and pistillate parts;

2, flower in late summer.

69

FIELD BOOK OF PONDS AND STREAMS

in Massachusetts and Connecticut. Other common names
are cat-tail flag, cat-o'-nine-tails, candlewicks. Blooms in
June-July. Fruits, August-September.

Animal associates. — An insect population lives upon cat-
tails the year around. Plant-lice feed upon the surfaces of
their leaves and the leaf -mining moths Arzama obliqua and
Nonagria ohlonga tunnel through them. The cat -tail moths,
Lymncscia phragmitella, lay their eggs upon the lower, pistil-
late half of the spike and their larvae spin silken threads about
the flower spike and bind it together. By thus fastening the
seeds in place, they preserve them through the winter for their
own food and protection. Old flower spikes like these are
frayed out two or three times their natural diameter. In
winter the larvae are snugly covered and in spring their co-
coons are protected there or in the stems. As many as seventy-
rix cocoons have been taken from a single pistillate spike.
During winter and spring the uninfested spikes lose their seeds
entirely but wherever larvas are present the seeds stay fastened
until the following summer when the spikes finally break off.

The larv^ae of the snout beetles, Colandra pertinax, feed on
the starchy core of the root-stock and upon the stalks.

Narrow-leaved cat-tail, Typha angustifolia. — Both leaves
and flower-spikes of the narrow-leaved cat-tail (Fig. 60) are
more slender than those of the broad-leaved species and the
upper staminate section of the flower is conspicuously sepa-
rated from the pistillate part by a stretch of bare stem.

Occurrence. — This species lives in the same marshes and
pond borders with the broad-leaved cat-tails but it is not so
widely distributed. Mainly along the coast from Nova Scotia
to Florida, often in brackish water. Inland it is locally com-
mon around the Great Lakes. Blooms June-July.

Bur-reeds — Sparganiacece

The bur-reeds are a company of plants which are very
similar in looks and habits; they all have reed-like leaves,

70

Fig. 6o. — Narrow-leaved cat -tail, Typha angusti-
folia.

71

FIELD BOOK OF PONDS AND STREAMS

their fruits are green burs of closely packed nutlets and all
grow in marshy pond borders or shallows

Fig. 6i. — i, Giant bur-reed, Sparganium eury-
carpiim; 2, branching bur-reed, Spargaiiium ameri-
canum.

72

HIGHER PLANTS

Giant bur-reed, Sparganium eurycarpum. — Giant bur-reeds
(Fig. 6i) grow along pond and stream borders among water
plantains, arrowheads, and pickerel-weeds. They are from 3
to 6 feet high v;ith very long ribbon-like leaves, about three-
quarters of an inch wide. The fluffy balls of their staminate
flowers are borne above the larger pistillate heads. The
fruits are green spheres of wedge-shaped nutlets packed close-
ly together like the sections of a pineapple.

Occurrence. — In shallow water or on the shore, especially
in the larger marshes. Common. Blooms early June-late
July. United States, less frequent near Atlantic coast, rare
and local in Connecticut.

Branching bur-reed, Sparganium americanum. — The plants
are similar to the giant bur-reed, but much more slender and
only I to 2 feet high (Fig. 61). The flower stems are more
or less branching but unbranched forms are often found in
the same colony with the others.

Occurrence. — Common in many bogs, borders of ponds and
streams. Blooms June-August. Eastern states, south to
Florida, west to Minnesota.

Animal associates. — Larvae of the leaf-beetle, Donacia, feed
upon its submerged roots (p. 280).

Pondweeds — NajadacecB

The pondweeds are probably more important to the wel-
fare of water animals than any other group, of aquatic seed-
plants. There are about forty North American species and
nearly every one of them flourishes in great numbers, provid-
ing either food or shelter for animals. They grow rooted to
the bottom and their long shifting leaves fill acres of pond
and lake water. Most of them are wholly submerged, except
for their flowers; in a few, like P otamogeton fiatans (Fig. 62),
the uppermost leaves float on the surface.

Animal associates. — In Lake George, N. Y., pondweeds are
known to the local fishermen as "weeds" and the "weed"

73

FIELD BOOK OF PONDS AND STREAMS

beds with their population of little clinging organisms furnish
shelter and food for most of the smaller fishes of the

lake.

Pondweeds are one of the principal foods of wild ducks.
They are so vital to animal life, especially to wild fowl, that
ponds are planted with them and a growing literature is
concerned with their biology and economic importance.
Bullheads, perch, and pickerel hide among them and a large
snail population, chiefly of Planorhis, Lymnma, and Physa,
gets its living from their leaves.

Fig. 62. — Pondweeds: i, Potamogeton natans; 2,
P. crispus.

Potamogeton natans. — This is one of the commonest pond-
weeds (Fig. 62). Its floating leaves have long stems or peti-
oles and oval blades but the submerged ones are incomplete
and thread-like, only the petiole being developed.

Occurrence.— In shallow ponds; frequent. Blooms June-
September. Almost cosmopolitan in temperate countries.

74

HIGHER PLANTS

Brown-leaf or ruffle-leaf pondweed, Potamogeton crispus. —

Sometimes called the crisp-leaved pondweed, this species has
long, very translucent brown leaves with crisped wavy edges
(Fig. 62). The flower stalk bears 3 to 10 small flowers and
although each flower has both stamens and pistil these do not
mature simultaneously so that pollination occurs only when
the wind carries pollen from the stamens of one flower to
some other one on which the stigmatic surface of the pistil
is ripe.

This pondweed is found in pools and streams, or along lake
shores where there is considerable wave action ; in such regions
its plants are apt to be dwarfed. They usually grow in water
from I to 5 feet deep; sometimes in depths of 7 to 8 feet.
They reproduce asexually by means of "burs" or winter
buds, sections of the stems which break off, lie over the winter
at the bottom and sprout forth new shoots in the spring.

Occurrence. — Ponds and lakes, often in brackish water, fre-
quent or common. Blooms June-July. Massachusetts north
to Ontario, south to Virginia. Naturalized from Europe.

Animal associates. — Larvae of chironomids and the moth
Nymphula, and snails are commonly found feeding on its
leaves. Wherever pondweeds are abundant they largely
support the chironomids which in turn become important
fish food. Potamogeton crispus is such a favorite food of wild
ducks that game ponds are planted with it.

Sago pond-weed, Potamogeton pectinatus.- — Like Potamoge-
ton natans this is a very common pondweed especially in
brackish water. It is one of the earliest to appear in spring,
sprouting forth from tubers early in April. The plants grow
entirely submerged in a depth of i to 6 feet of water and some
of the deep water ones are easily 8 feet long.

Occurrence. — In slow streams and lake borders often in
brackish or limy water. Blooms July-September, Quebec to
British Columbia, along the coast to Florida, to Pennsylvania,
Great Lakes, Kansas, Colorado.

75

FIELD BOOK OF PONDS AND STREAMS

Water-plantains and Arrowheads — Alismacece

These are border-line plants, which are very adaptable to
a changing water supply and show a consequent variation
in the form of their leaves. The flowers have 3, often con-
spicuous, white petals; pistils and stamens may be in the same
flower, in different ones on the sam€ plant, or on different
plants.

Broad-leaved arrowhead, Sagittaria latifolia. — Arrowheads
grow on wet shores or in shoal waters in company with bur-
reeds and bulrushes, pickerel- weed, and water-plantains
(PI. X). Broad-leaved arrowheads (Fig. 63) are 6 to 24
inches high with dark green arrow-shaped leaves and deli-
cate, 3-petaled white flowers which are arranged in whorls
of threes with the pistillate or female flowers in the lowest
cluster. The shape of the leaves in this and other species
varies with the depth of water and, in lakes, with their ex-
posure to the action of waves. Plants which grow in deeper
water usually have narrower leaves, but narrow and broad
leaves are often found on plants only a few inches apart.
Arrowheads adapt themselves to either droughts or floods
and when submerged they develop narrow ribbon-like leaves.
A single plant sometimes has a few narrow grass-like leaves,
some broadly ribboned ones, and still others which are arrow-
shaped. If a drought has left the plant stranded without water,
the narrow water leaves fall off and broad arrow-shaped ones,
better suited to work in the air, gradually take their places.
Adjustments like these are very common in all the arrow-
heads and they live in or out of water with all the ease of frogs.

Occurrence. — This and other species all grow on the margins
of quiet streams or in the protected bays of ponds and lakes.
Blooms July-August. Very common throughout the eastern
states.

Animal associates. — Arrowheads are pollinated by water
insects, mainly by damselflies and dragonflies which keep

76

HIGHER PLANTS

Fig. 63. — Broad-leaved arrowhead, Sagittaria
latifolia.

alighting on the flowers, even though they have no appetite
for their pollen. Water snails eat the flower petals and some-
times carry pollen from one flower to another.

77

FIELD BOOK OF PONDS AND STREAMS

Water-plantain, Alisma Plantago-aquatica. — Water-plan-
tains (Fig. 64) belong to pond shores and ditches but they also
grow commonly in almost every little pool, and with bed-

FiG. 64. — Water-plantain, Alisma Plantago-aqua-
tica.

78

HIGHER PLANTS

straw and swamp milkweeds in the marshes. Like arrow-
heads they readily adapt themselves to land life. They are
I to 3 feet high, and bear strongly veined leaves with long
petioles which grow from the root. The 3-petaled white or
pinkish flowers are very small, hardly more conspicuous than
their branching stems.

When seedling water-plantains are set in pots of earth sub-
merged in shallow water, and kept growing there for a couple
of months, they will develop into typical water plants, with
some floating leaves and others which are narrow and ribbony
like those of fresh water eel-grass (p. 80).

Occurrence. — On shores and in shallow water, in muddy
ditches and swamps. Blooms July-August. Common
throughout the United States.

Animal associates. — Adult syrphus flies which feed on its
pollen (p. 299) are its most frequent visitors.

Water-weeds and Eel-grass — Hydrocharitacece

Water-weed, Elodea canadensis. — Elodea, or Philotria
(Fig. 65), is a true aquatic, loosely rooted on the bottom or
floating free in the water, entirely submerged, and growing
so successfully in water that solid beds of it fill many ponds
and slow streams. Its branches are crowded with dark green,
translucent leaves arranged in whorls of three or more. They
have a single, central vein, and are so thin that they become
transparent and papery with very little exposure to the air.
Stems of Elodea are brittle and whenever broken the frag-
ments continue to grow independently, rapidly increasing
the number of plants. The flowers are inconspicuous; in
one species the female ones are borne on very long stems
which reach up to the surface of the water; while the short-
stemmed male flowers form low on the same plants but break
off and rise to the surface, where they meet the female flowers.

Elodea is a beautiful water plant but it spreads with amaz-
ing rapidity and crowds out other plants. English botanies

79

FIELD BOOK OF PONDS AND STREAMS

make frequent mention of its habits in rivers. In 1848, the
curator of the Botanic Garden at Cambridge introduced it
into a tributary of the River Cam and by 1852 it had spread

Fig. 65. — Water-weed, Elodea cayiadensis.

into the river, choked the drainage, and even stopped the
rowing.

Occurrence. — It is very common in slow streams, in back-
waters off main channels, and in ponds (PI. X). Blooms
July-August. Eastern states south to Virginia and Ken-
tuck>', west to Wyoming. Other common names are ditch-
moss, choke pondweed.

Animal associates. — ^Snails find good foraging grounds on
Elodea leaves and it is not unusual to find a six inch branch
loaded with four or five of them (Fig. 34).

Fresh water eel-grass, wild celery, Vallisneria spiralis. —
Fresh water eel-grass (Fig. 66) is familiar to canoeists and

80

HIGHER PLANTS

waders who often find shallows of lakes and creeks clogged
with its streaming leaves. It is always rooted in the bottom
and the leaves may be a yard or more long though scarcely

^:'^'i-&^^^ ' '-"^'^ '' /

Fig. 66. — Eel-grass, Vallisneria spiralis.

a quarter of an inch wide, bending with ever>' shift of the
current. The small greenish female flowers are borne singly
on the ends of long spiral stems so supple and springy that
they are not pulled under water when wind ripples its sur-

8r

FIELD BOOK OF PONDS AND STREAMS

face. The short-stemmed male flowers develop near the
base of the plant, several hundreds of them in each cluster,
the separate flowers becoming detached as they mature. A
bubble of air in each one buoys it to the top and there it opens
and floats along the surface till it meets the female flower.
The male flowers congregate in great numbers about the
larger female ones to which their sticky pollen finally adheres.
After pollination the spiral stem of the female flower con-
tracts and pulls the maturing fruit down into the water.

Occurrence. — Common in quiet waters. August. Eastern
states to South Dakota, and Texas; occasional on Atlantic
Coastal Plain.

Animal associates. — Fresh water eel-grass is the favorite
food of the canvas-back duck and other water birds. It is
an excellent aquarium plant, growing easily and providing
abundant oxygen for the animals (Fig. 35).

Duckweeds — Lemnacece

All the duckweed family are very small and all float upon
the surface of the water; among them are the Wolffias (Fig.
70), the smallest of the flowering plants. They have no true
leaves nor stems but the green plant body or thallus is usually
called a leaf and it looks very much like one. Minute flowers
grow directly out of it, borne from its side or upper surface.
The male flower is only a single stamen, and the female flower
a single pistil. Both are rare, for duckweeds usually repro-
duce by "budding off", or division of the thallus into two
parts, each of which produces roots and becomes a new

plant.

Greater duckweed, Spirodela polyrhiza.— In many regions
this species (Fig. 67) is the common duckweed, forming the
green water blankets made of thousands of little plants float-
ing on the surface, each with 4 to 16 rootlets hanging from it.
The thallus is circular, usually about a quarter of an inch
wide, green above and pinkish purple beneath; its 5 to 15

82

HIGHER PLANTS

simple veins and a cluster of 5 to 10 rootlets distinguish this
species.

^ W

Fig. 67. — Greater duckweed, Spirodela polyrhiza.

Occurrence. — Floating on the surface of pools, in marshes
and ponds, often very abundant in park and garden ponds.
June-early September. Common through most of the
United States, except toward the north, less frequent near
the coast.

Animal associates. — As their name implies, these plants are
a favorite duck food. The}'" grow very rapidly, crowding
together in blankets which often so complet-ely shut out the
light from the water beneath that the submerged plants die
and the herbivorous insects and crustaceans are forced to
migrate for food (PL II, 2).

Ivy-leaved duckweed, Lemna triscula. — The ivy-leaved
duckweeds (Fig. 68) form zigzag chains and lattices floating
just below the surface of the water. The thallus is oval or
lanceolate; their habit of remaining connected makes the
fanciful lattices.

Occurrence. — In ponds and ditches, especially in cat-tail

83

FIELD BOOK OF PONDS AND STREAMS

Fig. 68. — Ivy-leaved duckweed, Lemna triscula.

marshes. Frequent. Blooms in June-August. Rare near
the Atlantic coast but otherwise generally distributed over
the United States.

Lesser duckweed, Lemna minor. — In spite of their small
size these duckweeds (!?ig. 69) also form green blankets on the

^

^¥='

IT'

r

Fig. 69. — Lesser duckweed, Lemna minor.

water. The thallus is but a small fraction of an inch long,
has but one root, and i to 5 simple veins.

Occurrence. — Very common, floating on quiet waters of
ditches and ponds, sometimes on wet mud. June-August.
Throughout North America except in extreme north.

84

HIGHER PLANTS

Wolffia Columbiana.— The Wolffias (Fig. 70) are the small-
est of all the flowering plants. They float just below the
surface film, minute green grains often wedged in among

Fig. 70. — Wolffia columhiana. (From Britton
and Brown.)

the duckweed plants. The thallus is about a millimeter
long, and Wolffias are easily recognized by this minute size
and the entire absence of roots. In autumn they become
so laden with their food store of starch grains that they sink
to the bottom and winter over there, rising in the spring after
they have used up their own load.

Occurrence. — In quiet water, often among duckweeds.
June-July. Occasional. Distributed over the United States,
less frequent near the Atlantic coast.

Pickerel-weeds — Pontederiacece

Pickerel-weed, Pontederia cordata. — Pickerel-weeds are
persistent invaders of water territory. Wherever brook-fed
ponds are being filled up they are usually in the front ranks of
vegetation which is crowding into the water (PI. V). They
grow I to 3 feet high with thick, broadly arrow-shaped leaves.
Their violet-blue flowers are crowded together in spike-like
clusters about 3 inches long; these fade so quickly that com-
paratively few perfect spikes of flowers can ever be found

(Fig. 71).

85

PI. V. — The pickerel-weeds (Pontederia cordata) are per-
sistent invaders of the water. Dragonfly and damselfly
nymphs cHmb up the stems and shed their skins.

Photo, by A. H. Morgan

PLATE V

HIGHER PLANTS

Fig. 71. — Pickerel-weed, Pontederia cordata, flow-
er spike.

Occurrence. — Common along stream sides and in pond
shallows. Blooms June-October. Generally distributed
through the eastern states, westward to Minnesota, and
southward to Florida.

Animal associates. — Pickerel-weeds are insect-pollinated;
their blue anthers being so placed that an insect cannot enter

87

FIELD BOOK OF PONDS AND STREAMS

the flower cup without brushing the pollen from them. The
mucky waters in which they grow are full of dragonfly and
damselfly nymphs which climb up them to shed their skins,
often returning as adults to lay their eggs on the stems just
below the water surface.

Fig. 72. — Water stargrass, Heteranthera diibia.

Water stargrass, Heteranthera dubia. — This is a plant of
the muddy shoals with roots in the mud, its grass-like leaves
submerged in the water. The small yellow flowers blossom
at the surface, growing from leafy thread-like tubes on the
sides of the leaf stems. (Fig. 72.)

88

HIGHER PLANTS

Occurrence. — In quiet shallows. Blooms July-October.
Height, 2-3 feet. Generally distributed in eastern states and
westward but rare near the Atlantic coast.

Buckwheats, Smartweeds, Knotweeds — Polygonacece

Water smartweed, Polygonum amphibium. — Water smart-
weeds (Fig. 73) have pink or rose-colored flowers sometimes

Fig. 73. — Water smartweed, Polygonum amphi-
bium.

very conspicuous by their abundance. The plants grow
near shore, in quiet shallows where their smooth, shining
leaves float upon the surface. Varieties and closely allied

89

FIELD BOOK OF PONDS AND STREAMS

species differ from this one in shape of leaves and depth of
the pink and rose flower color.

Occurrence. — Found locally in shallow calcareous water of
ponds, usually over sandy, but sometimes mucky bottoms.
Height, 3-6 inches. Blooms July-August. Generally dis-
tributed through northern states, southward to New Jersey,
Kentucky ; rare near the Atlantic coast.

Homworts — Ceratophyllacece

Hornwort, Ceratophyllum demersum. — Like Myriophyllum
(p. 99), which it resembles, Ceratophyllum (Fig. 74) grows
submerged in ponds usually well out from shore. Its narrow

Fig. 74. — Hornwort, Ceratophyllum demersum.

thrice-forked leaves are borne in whorls on floating branches
a foot or two long and true roots are absent. The seeds germi-
nate on the bottom but when the young plants are about

90

HIGHER PLANTS

three inches long, they float up near the surface and there
they remain. The minute male and female flowers borne at
the bases of the leaves never rise above the water but the
stamens of the male flowers break off and float to the surface,
there shedding their pollen which "rains" down upon the
female flowers. Ceratophyllum's entire dependence upon water
to carry its pollen shows how much more truly aquatic it is
than most higher plants of the water. Toward autumn the
ends of its branches break off, float about for a time and
are finally pulled down to the bottom partly by their own
weight and partly by their "living freight of aquatic mollusks,
insects, and annelids." Such branches winter over on the
bottom but with the return of spring they float up again
and grow rapidly.

Occurrence. — Common in ponds and slow streams. June-
August or September. Throughout North America except
in the extreme north.

Animal associates. — Horn worts grow in ferny beds so thick
that they leave no place for any other plants. These horn-
wort forests are literally animated by a great population of
snails, worms, and small animals which feed upon one another
or upon the algae which cover the homworts.

Water-lilies — Nymphceacece

Spatterdock or yellow pond-lily, Nymphaea advena. — Al-
though yellow and white pond-lilies often Jive together the
yellow ones (Fig. 75) are commoner and thrive in many ponds
where white ones are not found at all. They grow in densely
populated shallows where pond-skaters dart about on what-
ever water they can find, where hundreds of spring-tails
make gray-black patches on the surface, and companies of
whirligig beetles come swinging in from open water (PI. II).

Their leaves are stockier and more ovate than those of the
white lily. The flower is a yellow or yellow-green cup formed
of six overlapping sepals; yellow stamen-like petals encircle

91

FIELD BOOK OF PONDS AND STREAMS

the large barrel-shaped pistil and yellow-green stamens are
packed closely against its sides (Fig. 75). During the first
day of bloom the flower cup opens only slightly but enough

Fig. 75. — Yellow pond-lily, Nymphcea advena: i,
flower; 2, flower cut to show the barrel-shaped pistil
and the stamens surrounding its base; 3, leaf.

to admit insects which come laden with pollen from other
flowers, brushing it on to the stigma already ripe to receive

92

HIGHER PLANTS

it. On the second day the same flower opens wide ; its anthers
burst with pollen and insects carry this to the stigmata of
other half -opened flowers. Thus cross-fertilization is brought
about and self-fertilization is prevented.

Occurrence.— Common in quiet waters. Blooms May-
September. New York southward and westward. In the
northwest and northeast it is largely replaced by a variety
whose flowers are partly purple.

Animal associates. — Leaf -miners eat channels through the
leaves and the caterpillar Nymphula cuts its waterproof
tents out of them (p. 258). The leaf -beetle Donacia lays its
eggs (Fig. 216) on spatterdock pads early in the season, and
on the white lily later when water has gone down leaving the
stiffer-stemmed spatterdocks high in the air. In winter
muskrats feed on the creeping rootstocks.

Small yellow pond-lily, Nymphaea microphylla. — This spe-
cies is a smaller edition of the common spatterdock. It is a
much more slender plant with yellow flowers scarcely an
inch wide; the stigma is dark red. Only locally common.
Blooms July-August. New England to Pennsylvania and
Minnesota.

Pond-lily, Castalia odorata. — Pond-lily (Fig. 76) and sweet
water-lily are common names for this plant which is well
known to everybody but especially to insects. Its familiar
rich green lily-pads, leathery and waterproof on the upper
side, often crimson beneath, can withstand hea\y rain and the
wear and tear of jostling by wavelets (PI. X) . The flowers are
pure white or pinkish with rich golden centers; the pungent
sweetness of a pond of blossoming lilies fills the neighborhood.
Stamens and pistil are in the same flower, but they mature
at different times and it is left for insects to transport the
pollen from one flower to another. The entertainment
offered to them is bountiful but brief; the flowers do not
open until the morning sun shines on them, and they close
in early afternoon. During that time they are probably

93

FIELD BOOK OF PONDS AND STREAMS

Fig. 76. — Pond-lily, Castalia odorata.

visited by a larger company of insects than are any other
water flowers.

Occurrence. — In ponds and in slow flowing streams.
Blooms June-October. Common. Eastern North America,
especially near the coast, west to Kansas.

94

HIGHER PLANTS

Animal associates. — The under sides of lily pads are hatch-
eries for eggs of beetles, snails, the caddis fly, Tricenodes, and
water-mites, as well as the homes and foraging grounds of
bryozoans, sponges, and snails (Fig. i8). Minute black
insects, known as thrips, abound in the blossoms near shore.

Mustards and Cresses — CriicifercE

Water cress, Radicula Nasturtium-aquaticum. — Among the
near relatives of this cress are other water cresses and the

Pig. 77. — Common water cress, Radicula Nas-
turtium-aquaticum.

95

FIELD BOOK OF PONDS AND STREAMS

common horseradish which like water cress is also a table
viand.

Water cress (Fig. ']']) may grow entirely submerged but in
summer it more frequently stands 6 to 8 inches above the
surface of shallow water and its branching stems spread out
and take root like runners on the bottom. The inconspicu-
ous white flowers have four petals forming the cross, a family
characteristic of the Cruciferce. In winter its bushy rosettes
make splashes of verdant green in spring-fed brooks.

Occurrence. — Springs and brooks; frequent and locally
abundant. Blooms June-July. Generally distributed over
the country, in the eastern states southward to Virginia.

Pitcher-plants — Sarraceniacece

Common pitcher-plant, Sarracenia purpurea. — Pitcher-
plants (Fig. 78) grow in peat bogs where their red-green pitch-
ers usually rise out of beds of pale sphagnum moss. Their
leaves are true pitchers which hold water and they can gener-
ally be found partly full of it from the rain. They are 4 to
8 inches long, green, with dark red veins, streaked with what
Schuyler Mathews has called "raw-meat coloring," and
have a tough papery texture. The flaring lip of the pitcher
is heavily streaked and is covered with stiff hairs which all
point toward the water; insects which pass over them fall
down into it, finally drown there, and their decomposing
bodies are absorbed by the plant. The curiously shaped
flower is green and maroon-red, like the leaves. Its 4 or 5
red-lined sepals curve loosely over the green petals that fit
about the pistil. This is umbrella-shaped and its stigmatic
surface — the inside of the umbrella — is turned upward be-
neath sepals and petals which protect it from ever^'thmg
but insects.

Common names of pitcher-plants show how playful and how
dangerous they have always appeared, — whippoorwill's

96

HIGHER PLANTS

shoes, Adam's pitcher, fever-cup, sidesaddle flower, and small-
pox-plant.

Fig. 78. — Common pitcher-plant, Sarracenia
purpurea.

97

FIELD BOOK OF PONDS AND STREAMS

Occurrence. — In acid peat bogs, often in water-soaked
sphagnum. Like sundews, they are more truly bog plants
than aquatics. Bloom May-July. Locally common from
Labrador to Florida and west to the Rocky Mountains,
abundant near the coast.

Animal associates. — Most associates of the pitcher-plant
are flying insects — small flies, moths, and beetles. Their
adventures in its leaves fend in fatalities except for a few that
have become adapted to dwell there. Among these is the
mosquito Mdes which even lays its eggs in the fatal water
and there the young ones hatch but and live unharmed until
they fly out as winged mosquitoes.

Fig. 79. — Round-leaved sundew, Drosera rotundi-
folia.

Sundews — Droseracece

Round-leaved sundew, Drosera rotundifolia. — Sundew
leaves are clothed with long glandular hairs each holding a
droplet of a sparkling sticky fluid in which small insects be-

98

HIGHER PLANTS

come entrapped and die. The struggles of these captured
insects stimulate the glandular hairs to secrete the fluid, and
the more they struggle the better the plant can hold them.
The leaves of any lusty sundew are covered with shriveled
insects whose juices the plant is slowly consuming.

The round-leaved sundew (Fig. 79) grows in a rosette about
2 to 3 inches high, its 5-petaled white flowers rising only a little
above the leaves. This is the commonest species but others
./'^Irequently found are the oblong-leaved sundew which has a
leaf 6 to 8 times as long as it is broad, the still narrower thread -
leaved and slender-leaved sundews. All of the sundews are
bog plants, trapping their insect food upon sticky hairs.

Occurrence. — The round-leaved sundew grows in spring-fed
calcareous bogs. Blooms in July. Generally distributed from
abrador, southwest to Florida and California including the
Atlantic Coastal Plain.

Water Milfoils — Haloragidacece

Mare's-tail, joint weed, Hippuris vulgaris. — Mare's-tail
(Fig. 80) is a perennial aquatic plant which grows on damp
shores or in shallows above which its stout plant stem pro-
jects for several inches. It is easily recognized by its whorls
of 6 to 12 ^^tiff, stringy leaves. Above the water they are
short and stand out stiffly from the stem but beneath it they
grow long, flaccid, and drooping. Its minute flowers are ar-
ranged in a circlet around the stem at the ba^se of the leaves.

Occurrence. — In ponds and quiet streams, especially in limy
or salty waters. Labrador southwest through New England,
New York, Minnesota, Nebraska, California.

Water milfoil, Myriophyllum spicatum. — Ferny milfoil gar-
dens are commonly found in slow streams and shallow ponds.
Milfoils (Fig. 81) are rooted to the bottom but their long
graceful branches reach nearly to the surface and their deep
purple staminate flowers project above it. There are several
species all of which have finely divided leaves.

99

FIELD BOOK OF PONDS AND STREAMS

Fig. 8o. — Mare's-tail, Hippuris vulgaris. (From
Arber.)

Occurrence. — In brackish or fresh ponds and slow streams.
Labrador to Alaska, south to Connecticut, the (Sreat Lakes
region, and the southwestern states.

Bladderworts — Lentihulariacece

Bladderwort, Utricularia vulgaris. — Although more innocent
looking plants than the sundews, the bladderworts (Fig. &2)
bear hundreds of death traps for minute water animals.
There are several species of them, all delicate, vine-like plants,
which float beneath the surface among the stems of water-
lilies, and pondweeds. Their presence is the sign of an
abundant population of protozoans, nematode worms, roti-
fers, and small crustaceans (PI. IV). ^

100

HIGHER PLANTS

Fig. 8i. — Water milfoils, Myriophyllum spicatum.

Bladderworts have slender stems which bear finely branched
leaves arranged alternately but divided so close to the base
that each leaf appears like two leaves growing opposite to
eacn other. On the branches of each leaf are the small
bladder-like traps or utricles. There are no true roots but
one end of the plant bears green, twig-like rhizoids which
perform the work of roots. Air shoots will grow up from the
surface when the oxygen supply is low in the water. This
bladderwort has yellow flowers on stalks which extend 3 or
4 inches above the water. Each bladder is a slightly com-

lOI

FIELD BOOK OF PONDS AND STREAMS

pressed sac (Fig. 82, 2) with a slit-shaped opening; this open-
ing is guarded by a valve and the rim of the vestibule is
armed with teeth and bristling hairs. Within the bladder

Fig. 82. — Bladderwort, Utricularia vulgaris-, i,
branch with bladders; 2, bladder more enlarged.

there are more branched hairs, and a digestive secretion is
produced from the walls. When little organisms enter the
vestibule their movements stimulate the valve to open.
Ordinarily the sides of the sac are dented inward (Fig. S2)
but as soon as the valve opens the entering water presses its
walls from within and at once pushes them outward. This
outward movement starts a suction that pulls water and
animals with it into the bladder; thus making it at least in-
directly the active captor of its prey. By first counting all
the animals in a certain number of bladders and then all of
the bladders on a stem, Hegner has estimated that all stems
taken together on one large plant contained 150,000 living
organisms. The bladders which he studied were indented
again and "set" for another capture in about 20 minutes
after one had taken place.

102

HIGHER PLANTS

Occurrence. — Frequent in quiet water containing much
organic matter. Blooms July-August. United States south-
ward to Virginia and Texas and in scattered areas westward
to Arizona and Lower California.

Animal associates. — These are mainly protozoans, nema-
todes, rotifers, minute insect larvae, and crustaceans. If a
plant with translucent empty bladders is put into an aquarium
well supplied with entomostracans (p. i6i), its bladders will
soon become darkened by their loads of captured animals.

103

CHAPTER VI

SPOXGES

Porifera

Form and habits of sponges. — To most people the word
sponge means bath-sponge. To others it calls to mind the
sulphur-sponges of the New England coast or the glassy
lace work of the Venus' fiow^er-basket of tropical waters. At
any rate it probably suggests salt water and this association
is quite natural, for salt water sponges exist in an infinite
variety of shape and hue. There are hardly more than 40
to 50 species of fresh water sponges yet known in North Ameri-
ca. They are dull-colored, greenish, often moss-like (PI. X),
usually not seen and even if they are noticed, their real
identity is not suspected.

Fresh and salt water sponges both consist of colonies of
animals which are living together. In close view a fresh
water sponge and a piece of bath-sponge look much alike.
Both have uneven hubbly surfaces peppered with thousands
of holes, the pores which have given the name Porifera to
the sponge group (PI. VI, i). Leading from these pores is a
network of canals and chambers in which food and water
pass through the soft body tissue of the sponge. All sponges
are alike in having a lattice-like supporting framework or
skeleton upon which their soft tissues are arranged. This
skeleton may be tough and elastic — the spongin of the bath-
sponge; glassy — of silicious spicules like the glass sponge;

104

SPONGES

or it may be a combination of both. In any case it is the
hardened secretion of the soft sponge cells. The skeleton
of the fresh water sponge is composed of little transparent
needles, spicules of silica, the largest of them about one hun-

FlG. 83. — I, Diagram of section of a fresh water
sponge growing on stone; arrows indicate currents
of water through canals and chambers ; note spicules
in sponge walls: A, incurrent pore or osteole; B, in-
current canal; C, flagellate chamber where food is
taken into the cells; D, excurrent canal; E, gastral
chamber; F, excurrent pore or osculum. 2, Micro-
scopic spicules greatly enlarged, within cells which
form them.

dredth of an inch, straight or curved, smooth or covered with
brier-like points, or dumbbell-shaped and sculptured but
always hooked or bound together in interlacing chains. In
young sponges, grown on glass, bundles of them can be seen
projecting through the filmy outer covering (Fig. 86).

The holes on the surface of sponges are of two sizes, small
incurrent pores or osteoles (Fig. 83, A) where water comes in
and larger excurrent oscula (Fig. 83, F) where it passes out
of the sponge. After water has entered the osteoles it is
helped onward by the briskly waving flagella in the flagellate
chambers (Fig. 83, C). There any food it contains is taken
into the sponge cells but most of it passes on through a canal

105

PL VI. — Photographs of living sponges: i, colony of Spong-
illa, natural size; 2, sponge colony on glass, 7 days after gem-
mules (dark spots) were taken from the brook.

Photo, by A. H. Morgan

PLATE VI

SPONGES

(Fig. 83, D) into the gastral chamber (Fig. 83, E). Here it
mixes with water from other canals and finally goes out of
the osculum (Fig. 83, F), carrying waste matters with it.
In a young sponge the oscula are at the tops of chimney-like
elevations, and with a lens, waste particles can be seen coming
out of these "chimneys" along with the water (Fig. 85).
Sponges are wholly dependent upon currents of water for
bringing them food and carrying away waste; they may be
fed or smothered to death, depending upon whether currents
bring clean water supplied with food or water heavy with
silt. Sponges cannot move from place to place but their
gemmules or winter buds (Fig, 84) have been carried about
by birds and by currents of water ; and sponges have thus been
widely distributed through lakes and streams.

Habitat. — Sponges can live only in clean water. They
grow upon water-soaked logs sometimes in large masses, on
the leaves of submerged plants, and often with bryozoans
on the undersides of stones in riffly brooks. It is not strange
that they are abundant on sluiceways and pipes at the
outlets of reservoirs, where the water is free from mud and
rich in microscopic organisms. Water-pipes are often lined
with rough coatings of sponge a quarter of an inch or more
thick which hinder the flow of the water and sometimes totally
clog the pipes. Occasionally the sponge decays and throws
out impurities, giving the well-known "swamp taste" to
the water. Sponges and bryozoans are both called "pipe
moss" by sanitary engineers. When the Metropolitan Water
Works were installed in Boston, an old sixteen-inch pipe was
opened which had been laid ten years before. Scattered over
the usual coating of rust were numerous patches of sponge
as large as the palm of one's hand. These were all growing
lustily without any light at all since th&» unfiltered reservoir
water was clean but full of food.

Sponges often live where they are flooded with sunlight
and then they are colored green by the chlorophyll of minute

107

FIELD BOOK OF PONDS AND STREAMS

plant cells, the zoochlorellas, which grow within their own
cells. It is a common occurrence to find green sponge colonies
on the upper surfaces of submerged logs (PI. X) and yellowish
or nearly white ones on the under side.

Distribution. — Only 40 or 50 species of fresh water sponges
are known in North America. Two of the commonest,
Spongilla fragilis and Spongilla lacustris, are found in the
eastern states and as far west as Kansas. There are fewer
records of sponges in the southern states and those beyond
the Mississippi River but this is probably due to lack of study
rather than a scarcity of sponges.

Fig. 84. — Fresh water sponge in winter, gemmules
held among interlacing spicules.

Season. — Colonies are at the height of their growth in July
and August. In the early fall most of them begin to shrivel,
by October *id November the}^ are dead, and only the gem-
mules or winter buds remain, held among the interlocked
spicules. These are»the only parts of sponges which live over
the winter; in March and April young colonies begin to grow
from them, first appearing as tiny flecks of white upon sub-
merged stones and twigs.

108

SPONGES

Associates. — Fresh water sponges harbor very inconspicuous
little parasites — the six-legged larvae of Spongilla-flies which
descend into the osteoles or pierce their way into the soft
sponge cells with their sharp mouth-parts (Fig. 187). They
can not only pierce the cells, but they can suck out the con-
tents as conveniently as we can drink through a straw. Each
of their slender mandibles is hollowed out on its inner side,
and when held closely together they make a perfect tube
through which the watery content of the sponge cells is easily
drawn. Spongilla-flies have transparent bodies and their
stomachs are always so full of sponge that they are literally
sponge-colored, inside and out, and a more convincing camou-
flage would be hard to find. One must search for one of these
larvae with a lens ; it will scarcely be noticed unless it is moving
and even then it \odks like a piece of sponge on legs.

Study and collecting. — It is difficult to distinguish fresh
water sponges and in order to identify a species one should
know the form of the colony, the spicules and gemmules as
well. When specimens are collected for identification, care-
ful note should be made of the living colony and its habitat
and a piece of it scraped off and preserved in alcohol or forma-
lin. Gemmules can be found in late autumn, occasionally in
summer, and their general structure can be made out with a
pocket-lens, but a microscope is necessary to see the spicules.

A winter study of living sponges. — An interesting winter
study of gemmules can be made with only a dish, some pieces
of glass, and a pocket-lens for tools. In early winter, gemmules
look like so many fig-seeds clustered among the spicules (Fig.
84) and may easily be scraped into water and taken home.
Then water, preferably from their own brook or pond, should
be poured into a deep pie-plate, a few pieces of clean glass
placed in the bottom, the dish set where it will not be jarred,
and finally the gemmules dropped onto the glass. They
should be left undisturbed for two or three days, at room
temperature and out of direct sunlight. A little fresh water

109

FIELD BOOK OF PONDS AND STREAMS

should be added so gently that the gemmules will not be
shaken. Within a day or two they stick to the glass, no longer
rolling with the slightest tremor of the water. This is the
first sign of growth, and shows that the soft sponge cells have

Fig. 85. — Sponge colon}'- 3 days old with the gem-
mules from which it has grown. Note chimney-
like elevations.

grown out through the little hole in the gemmule shell, over
its side and onto the glass. They make the white plug which
shows in the hole and the white drift around the dark gem-
mule (Fig. 85). By the time the colony has been growing
three or four days little elevations will appear on its surface.
At first their tips are translucent bulbs but these soon break
through and the whole structure becomes chimney-like with

Fig. 86. — Beginnings of the sponge skeleton; the
spicules of silica (opal) showing on the edge of a
colony 6 days old.

no

SPONGES

an open osteole at the top. If a bit of finely powdered car-
mine or starch is scattered on the colony, the particles will be
carried down into the osteoles and will soon be seen coming
out of the larger oscula. If the colony, glass base and all, is
taken from the water for a moment and held up to the light,
the translucent spots and streaks will tell where chambers
and canals have already formed within it (PI. VI, 2). When
a colony is five or six days old its spicules will prick through
the filmy covering of its transparent border (Fig. 86).

Identification. — Fresh water sponges have been separated
into two groups according to the structure of their gem-
mules ; one contains those in which the opening of the gemmule
is a simple hole, the other those which have it at the end of a
short tube; they have been further classified by their spicules.

Although traits and general form are helpful, for the final
identification of fresh water sponges microscopic study is
necessary. Ward and Whipple's "Fresh Water Biology"
and Pratt's "Manual of Invertebrate Animals" both contain
illustrated keys to the fresh water sponges.

Ill

CHAPTER VII

THE HYDRAS, FRESH WATER JELLYFISHES

•

Coelenterata

Form and habits of hydras. — The hydras (Fig. 87) are al-
most the only fresh water representatives of the great pre-
dominantly marine group of Coelenterata to which the jelly-
fishes, sea anemones, and corals belong. They are soft trans-
parent animals which can stretch themselves until they are

Fig. 87. — Hydras hanging from plants in an aqua-
rium.

half an inch long, or contract till they are as small as pinheads
(PI. IV). When a hydra is extended it looks like a piece of
string frayed out at one end. The frayed strands are a circlet
of tentacles which surround the mouth, and bring to it any

112

THE HYDRAS, FRESH WATER JELLYFISHES

food which they can reach. Its other end is a kind of foot
supplied with a sticky secretion, enabHng the hydra to hold
itself to submerged twigs or even to the under side of the
surface film of water. Clinging by its sticky foot it can glide
along so slowly that it is hard to realize that it moves at all.
Nearly all over its body, especially on the tentacles, there are
peculiar stinging cells containing poison sacs. There are

sbervno.r(

o\/iar(

*ASiS>

Fig. 88. — Diagrams of hydras (H. oligactis) show-
ing bud and reproductive organs.

usually two or three sizes of these and on the tentacles they are
arranged in batteries from which their poison sacs are explod-
ed at the slightest touch or invitation. These sacs are to
some extent defensive weapons, but they are probably of
more value in capturing some of the lively organisms upon
which hydras feed.

When feeding, a hydra hangs attached by the foot, swinging
its tentacles nonchalantly about in the water until one of them
touches something (Fig. 87). If it is a Daphnia (p. 165) or
something equally appetizing the tentacle will instantly pull
it toward the mouth. The other tentacles then contract and

113

FIELD BOOK OF PONDS AND STREAMS

join in the team work of paralyzing and pulling in the prey.
Hydra swallows its food into a capacious central cavity or
ccelenteron, the only cavity in its body. There it is digested
and the useless part cast out of the mouth. Hydras are
gluttonous feeders and they will eat till their bodies swell out
like meal-sacks, the food being clearly visible through their
transparent sides (Fig. 89).

They reproduce both by sex cells and by budding, but the
two kinds of reproduction usually occur at different seasons,

Fig. 89. — Hydra oligactis after a full meal.

var^'ing with the species and with their living conditions
(Fig. 88). Buds are most apt to appear when the animals
are well fed. A young hydra bud will stay attached to its
parent for some time after it has a mouth of its own and is
doing its own eating, but the food which the young one eats
may stay in its own coelenteron or it may pass on into the
parental food cavity. In sexual reproduction thousands of
sperm cells are produced in the spermary, a cone-like eleva-
tion near the base of the tentacles (Fig. 88). Only one egg
is formed in the ovar\% the larger swelling near the foot, which
is less often present than the spermar>\ Spermary and ovary
are sometimes present upon the same animal, as they are in
the green hydra. Hydra viridissima (Fig. 90), but in most
species they are found on different individuals. An egg may

114

THE HYDRAS, FRESH WATER JELLYFISHES

be fertilized by a sperm cell from the same animal or from a
different one ; in any case fertilization occurs while the egg is
still attached to the parent's body. There the early develop-
ment of the young hydra begins under a kind of parental
protection.

Hydras tide themselves over dangers of the cold by means
of winter eggs which are formed and fertilized in the autumn.
Encased in a protective shell, the egg drops from the parent's
body, lies dormant over the winter, but resumes its develop-
ment in the spring. This is a safety device similar to others
such as the winter eggs of small crustaceans like Daphnia,
and of planarians, or the gemmules of sponges.

In the better known hydras like those just described there
is only one form of the body; but in certain fresh water jelly-
fishes to which these hydras are related the individuals of
one generation are very different from those of the next. In
this so-called "alternation of generations," the hydranths or
hydra-like animals of one generation differ greatly from' the
medusce or umbrella-like jellyfish of the next generation.
In the little known jellyfish, Craspedacusta, the hydra-like
stage is rarely seen, but the medusa form is occasionally found
in great numbers. In September, 191 6, millions of little
medusae of Craspedacusta were found floating in the waters of
Benson Creek about twenty-five miles from Lexington, PCen-
tucky, and again in September, 1924, though none had been
observed there between times.

Habitat. — Hydras live in sunlit pools on plant stems and on
the under sides of leaves, abundant in early as well as late
summer. Dr. J. G. Needham has reported that the "brick-
red" hydras were so abundant in early -summer at Saranac
Inn, New York, that the water was "tinged with red" by
them; and Kofoid collected 5335 hydras from a cubic yard of
water taken from Quiver Lake in the spring of 1897. Hydras
have been reported growing on the walls of filter beds; at
Auburn, New York, such a growth of hydra was brilliant pink

115

FIELD BOOK OF PONDS AND STREAMS

and occurred in cold weather when there was a lusty popula-
tion of small crustaceans which are their favorite food.

Food. — Hydras are carnivorous. They thrive on a diet of
minute worms and such small crustaceans as Daphnia, Cypris,
and Cyclops (Figs, 124, 128, 126), for which they compete with
the young fishes. In an aquarium hydras can be seen dangling
their tentacles lazily into the water reaching after the
Daphnias and finally ensnaring them with unbelievable
surety. They also swallow young insects and small clams,
casting the shells of the latter out of their mouths after the
soft parts have been digested. Hickson of the University of
Manchester, England, saw a hydra capture and hold a very
small tadpole in its tentacles. Another observer saw a hydra
swallow a small fish which extended from its mouth after it
had been taken in as far as was possible. In 1740 Abbe
Abraham Trembley, the pioneer student of hydras, described
their capture of baby fishes. In modern times hydras some-
times appear by thousands in hatchery troughs, creating
havoc among the very small fry, and they no doubt act the
same way in the natural homes of fish fry.

Associates. — Hydras may feed upon young fishes, but it is
well known that slightly larger fishes feed upon them. They
live on terms of a biological intimacy, known as symbiosis,
with at least two organisms. Green algae or zoochlorellas
live within the body cells of the green h^^dra as they do in
those of fresh water sponges and cause their brilliant green
color; and microscopic protozoans (Kerona pediculus) live
on brown hydras. There are often ten or fifteen of these
climbing over an animal at one time, but they are not known
to feed upon it nor to do it any harm.

Collecting, aquarium study.— When one is familiar with them
hydras can often be seen in still pond water hanging from plant
stems like Nitella and Elodea or from the under sides of lily
leaves. But it is usually necessary to gather a few water
plants and let them stand in a glass dish of the pond water.

116

THE HYDRAS, FRESH WATER JELLYFISHES

If hydras are present they will soon be hanging out into the
water (Fig. 87). They should be kept out of the direct sun-
light. Like other animals hydras will have a better chance
to live if they get used to water gradually so only a little new
water should be given them at a time. Sprays of water plants
such as Nitella, Myriophyllum, or Elodea will give off enough
oxygen for them and small crustaceans will be their best food.
Swarms of these can be dipped out of the water close to the
pond shore and hydras will live on them the year round.

In the aquarium their feeding habits can be watched; they
will even take a small worm or larva from forceps if it is moved
toward them very gently. They will hang from the side of
the aquarium, stretching their bodies and tentacles into tenu-
ous slenderness, circling slowly around within a radius of an
inch or more. Occasionally, one will attach its tentacles to
the glass, loosen its foot and move it over to the tentacles,
which are loosened, stretched, and pressed to the glass again;
then the foot is lifted again and extended and thus, the
whole animal moves, looping like an inch worm. Again the
same animal may elect to travel by turning slow motion
somersaults.

Identification. — The commoner fresh water Hydrozoa (Hy-
dras). Animals which have tentacles in a circlet about the
mouth and do not form colonies.

Fig. 90 — Green hydra. Hydra viridissima.

117

FIELD BOOK OF PONDS AND STREAMS

Hydra viridissima (viridis) (Fig. 90). — Green hydra. Body
grass-green; about 6 short tentacles; male and female organs
on the same individual, usually in summer.

Fig. 91 — Gray hydra, Hydra vulgaris.

Hydra vulgaris (grisea) (Fig. 91). — Body gray, orange, or
brownish; about 6 tentacles; male and female organs usually
on different individuals, in summer; 4 kinds of stinging cells.

Fig. 92. — Brown hydra, Hydra oligactis.

Hydra oligactis (fusca) (Fig. 92). — Brown hydra. Body
brownish, very slender at the proximal (attached) end; about
8 very long tentacles; 3 kinds of stinging cells. Difficult to
separate from H. vulgaris except by microscopical examina-
tion of the stinging cells.

118

CHAPTER VIII

FREE-LIVING FLATWORMS

Planaria

Most flatworms are parasites. All of the tapeworms which
abound in the food canals of fishes, and the host of flukes like
those which live on the skin and gills of mud puppies, on the
mussel Anodonta and within the bodies of turtles, belong to
this group. The turbellarians are the only flatworms that
are not parasitic. They are small animals whose steady glid-
ing motion is due to thousands of cilia whose turbulent lash-
ings have given the group its name Turhellaria. Although
turbellarians are generally abundant in fresh water, only the
planarians, the largest of them, are familiar; the others being
so minute that they are not often discovered. The small ones
are mentioned later but nearly all of this discussion refers
to the large planarians.

Form and habits of planarians. — Planarians glide over sub-
merged stems and leaves and forage on alga-covered stones.
They are soft, gray or velvety black flatworms commonly
measuring a half inch or less. They are flattened and look
like very small leeches. The shape of the head and body
varies but little, earlike flaps, called auricles, being character-
istic of many of the family. The mouth is on the end of a
short muscular tube, the pharynx, located in the middle of
the body. When a planarian is feeding it thrusts its pharynx
well out of the body, exploring with it like a kind of feeler,

119

FIELD BOOK OF PONDS AND STREAMS

and then sucks the food through it (Fig. 93, i). At other
times it is pulled back into the body through an opening on
the under side (Fig. 93, 2). This is visible only from beneath
or when a planarian glides upside down under the surface film
of the water. Food sucked in through the pharynx goes into
the large more or less branched intestine, which often shows as

Fig. 93. — Common planarians: i, upper surface
showing the ear-like auricles and the eyes, the
cylindric pharynx thrust out from the body as in
feeding ; 2, diagram of planarian showing its branched
food canal and the pharynx pulled back into its
sheath within the body.

a vinelike tracery on the backs of planarians. It has only one
opening and the waste must go out through the mouth just as
it does in Hydra.

Planarians are very sensitive to the conditions around them.
They appear uncomfortable in bright light, and will try to get
into a shadow or into the dark, in the meantime keenly dis-
criminating between small differences in the light. They
are responsive to very slight vibrations, especially sensitive
to temperature, and must have a sense of taste for they are
soon attracted to a crushed snail or any meat juice in the
water. With rare exceptions they are hermaphroditic, each
animal having a complete male and female reproductive
system. Most of them produce thin-shelled transparent
summer eggs as well as the thick-shelled winter eggs or
"cocoons." But though they are equipped with this elabor-
ate reproductive machinery, all turbellarians depend upon the

120

FREE-LIVING FLATWORMS

simple division of individuals to increase their numbers.
The common Planaria maculata divides transversely just
behind its pharynx (Fig. 94), only a little constriction show-
ing there at first. This grows deeper till the two parts hang
together by a mere thread, finally separating and moving
away from each other. The head soon grows a new tail,

Fig. 94. — Two individuals of Planaria being
formed by automatic division of the body.

and the tail region a new head. This kind of division is a
very frequent performance among planarians; one often
finds a partly divided planarian moving comfortably over
a leaf, no longer one animal, yet scarcely two. If plan-
arians are starved or kept in stale water they will divide too
often, not getting their growth between divisions, thus pro-
ducing planarians which remain pigmies as long as the bad
conditions exist. This kind of reproduction can be easily
imitated artificially by cutting planarians with a knife (Fig.
95). Ways to do this are suggested in the paragraph on
aquarium study.

Habitat. — Turbellarians occur in all kinds of fresh water at
any time of year, and their presence can be counted upon in
almost any aquatic society. Planarians live in shallow pools,
in streams, sometimes very swift ones, and in swampy places,
often among sphagnum mosses. A pool which at first glance
does not seem to have a planarian in it may shelter a popu-
lation of them hiding on whatever they can find there, stones
and trash and water plants. Drooping grasses which trail
into the water from the bankside may be black with planarians
on their under sides. One of the minute turbellarians,
Stenostomum (Fig. 96), lives in mats of Spirogyra and other
green algse.

Planarians prefer cool, even very cold water, and temper-

121

FIELD BOOK OF PONDS AND STREAMS

ature is quite as important as food in determining where
they live. A single species often lives in springs or ponds
which are very different in other ways, shallow or deep, rapid
flowing or slow, so long as their waters are uniformly cold.
The European Planaria alpina occurs in the high cold lakes
of the Alps, while in lower regions it is not found at all in
similar lakes where the water is warm, but only in rapid
brooks and in springs whose temperature is more like that of
the mountain lakes. Dr. Kathleen Carpenter has suggested
that some planarians are relicts of the Ice-Age, animals
brought from the north by the great ice-sheet, and left
stranded in warmer regions where they are now making the
best of it, living only in the coldest places.

Food. — All planarians are carnivorous and often cannibal-
istic. They thrive on crushed snail-meat and beef-liver,
devouring it greedily at night, the time when they are most
active. If a hungry Planaria macidata (Fig. 98) is turned
on its back in a drop of v.'ater and a piece of *snail-meat held
within its reach it will thrust out its pharynx and suck up the
meat juice till it is full to bursting. Planarians will gather in
groups ten to fifty strong upon pieces of meat which are
dropped into their dishes. They will eat hard-boiled yolk of
egg. The milky planarian, Dendroccflum lacteum (Fig. 97),
will fill its food canal with it till its whole back is yellow.

A few minute turbellarians, the rhabdocceles (Fig. 96), are
vegetarians, living on algae, diatoms, and especially Spirogyra,
on which they are sometimes abundant.

Aquarium study. — Planarians are easy to collect and can be
kept in aquaria for long intervals with very little trouble.
They cling to leaves when they are pulled from the water
or to stones and can be easily lifted from them with the point
of a knife. The aquarium for them should be supplied with a
shallow bed of clean sand, a few pebbles, several sprays of
Myriophyllum or some other water plant, and clean water kept
cool and out of bright light. Planarians cannot stand heat or

122

FREE-LIVING FLATWORMS

lack of oxygen. If they creep up and form a line along
the water's edge it means that their oxygen supply is running
low, more plants must be put in the aquarium or fresh water
added every day or two. Once or twice a week they should
have a meal of crushed snail-meat, or earthworm, or beef-
liver, and the w^ater should be changed the day after feeding.
Planarians will live for a long time, three months or more,
without any food, but they will become smaller and smaller,
using up their own bodies nearly to the vanishing point.

To test their power of growing new heads and tails it is
only necessary to have healthy planarians, a few small, clean
dishes so that each animal can have one to itself, and a knife
or a pair of scissors. Place a planarian in a shallow dish of
water, and press a sharp knife down across it while it is well
extended, or lift it out upon wet paper where it can be cut,
paper and all, with scissors. Planarians have no blood or
blood vessels to be injured by cutting and branches of the

Fig. 95. — Regeneration in planarians: i, a plan-
arian cut crosswise as indicated; 2, the regeneration
of the tail ; and 3, the head ; 4, a planarian cut length-
wise; 5, the regeneration of the left, and 6, of the
right side.

123

A

FIELD BOOK OF PONDS AND STREAMS

food canal go in all directions making every region capable
of digesting food and growing. If a planarian is cut crosswise
(Fig. 95) the head will grow or regenerate a new body and the
body a new head as they do in natural transverse division.
If one is cut lengthwise through the center of the body the
right side will regenerate a new left and vice versa. If no
food is given to these regenerating animals the growing side
will live on the older part and the whole animal will be
dwarfed.

Identification. — On the outside of their bodies turbellarians
have few external features by which the different species
can be separated. Their classification is based very largely
upon the sex organs which are undeveloped in all but the fully
grown animals and difificult to see at any time. The main
groups, however, are divided according to the shape of the
intestine, in this case m.eaning all of the food tract except the
pharynx, and often clearly visible through the transparent
body wall (Fig. 93, 2), Fresh water turbellarians have a
single, blind intestine as in the Order Rhabdoccelida or a three-
branched one as in the Triclada.

I. Turbellarians with a single, blind intestine. Order
Rhahdocoslida.

Fig. 96. — Stenostomum leiicops, showing the chain
of individuals produced by automatic division of
the body.

Stenostomum leucops. — This is a very common species
(Fig. 96) which may be here taken as a type of the rhab-
docoeles. These minute flatworms are common on plants in
quiet ponds, but are never more than a quarter of an inch
long, so small that they are seldom seen and even less often
recognized. They reproduce by budding, a kind of transverse
division, and their best recognition marks are the chains of 2
to 4, rarely 9, animals attached to one another, tandemwise.

124

FREE-LIVING FLATWORMS

Occurrence. — Northeastern states, New York, Michigan.

2. Turbellarians whose intestines have three main branches,
one running forward through the center of the body and two
which turn backward on each side of the pharynx. Order
Triclada.

3. Turbellarians with one pharynx. Dendroccelum, Plan-
aria.

,^ vtji-jsics-vs:^

Fig. 97. — Milky planarian, Dendroccelum lacteum.

Milky planarian, Dendroccelum lacteum. — These beautiful
planarians are creamy white with their food canals showing in
a tracery of brown (Fig. 97). Just behind the eyes there
is a constricted necklike region which makes the rounded
auricles more prominent.

These pale planarians crawl over the stones in shallow
streams. An occasional one can be found there throughout
the winter (PI. I). When collected such animals sometimes
lay their hard-shelled winter eggs shortly after they are
brought into the house. They are about the size of a mus-
tard seed, shiny, chestnut brown and raised on a tiny stalk.

Occurrence. — Eastern states.

Fig. 98. — Planaria maculata.

Planaria maculata. — Planaria maculata is one of the
commonest planarians (Fig. 98). Its body is slender,
about one quarter of an inch long, and tapers into a
pointed tail. The head is broader than the body, and pointed

125

FIELD BOOK OF PONDS AND STREAMS

in front with short auricles. These animals usually pass as
common black planarians. Their backs are irregularly
spotted with black, and smaller black spots are scattered
among the large ones so that the whole surface looks dark,
though a light streak sometimes runs along the middle. In
summer they reproduce almost entirely by transverse divi-
sions. They live in quiet waters, under stones, among algas,
often in groups of 3 to 5, or 15 to 20.

r

Occurrence. — Eastern states to Michigan and Nebraska.
4. Turbellarians with several pharynges.

Fig. 99. — Phagocata gracilis.

Phagocata gracilis. — These planarians are shiny black or
sometimes reddish-brown, one third to i inch long. They
are round headed and blunt tailed, remarkable in having
not one pharynx but twenty-two separate ones, each having
a mouth, and opening into the intestine, and all of them ex-
tensible through the single opening on the under side of the
body (Fig. 99).

Occurrence. — Common in pools, often in brackish water.
Massachusetts and Pennsylvania to Wisconsin.

126

CHi^PTER IX

WHEEL ANIMALCULES

Rotifera

Rotifers are transparent microscopic animals which live in
fresh or salt water. They abound in the surface waters of
great lakes, and swarm through the shallows of ponds and
bogs; there is scarcely any stand of soft water, whether
transient puddle or rain-barrel or fountain-basin, where
rotifers can not be found. They live in ponds and lakes,
pro"vading a large part of the food for small crustaceans
and worms and are thus indirectly a main source of food for
fishes.

Fig. I go. — Common rotifers: i, Philodina; 2,
Diglena, which sucks out plant cells; 3, Euchlanis,
showing shell-like lorica. (From Ward and
Whipple.)

127

FIELD BOOK OF PONDS AND STREAMS

Rotifer structures. — Most rotifers are solitary but others are
joined together in colonies and while the majority of them
move freely through the water, a few are attached to plants
or animals. Although they grow in an infinite variety of
shapes all of them have circlets of cilia which appear like
two rapidly rotating wheels at the front end of the body, hence
their name Rotifera or wheelbearers. Small as it is, a rotifer
has an outer covering, either a soft or a shell-like lorica (Fig.
100, 3), muscles, a food canal, nerves, complicated reproduc-
tive systems (Fig. loi).

Seen under the low power of a compound microscope the
wheels of the rotifer prove to be the rims of its corona or
head region circled with hundreds of cilia waving so fast that
they look like two whirling crowns (Fig. loi). B}^ means of

HEAD

CORONA

BRAIN
EYE

ASTAX
GASTRIC GLAND
STOMACH

OVARY

BLADDER

FOOT GLANDS

FOOT

TOES

HEAD

Fig. ioi. — Diagram of a rotifer showing circlets
of cilia and mastax. (After F. J. Myers.)

these lashing cilia rotifers propel themselves through the water
and collect their food. A rotifer's mouth is at the lower edge
of the corona and its short oesophagus contains the mastax,
a food pouch equipped with three teeth which crush and grind

128

WHEEL ANIMALCULES

up any delicate alga or protozoan which comes their way.
In the plant-eating rotifers the mastax works like a' suction
pump; the rotifer pierces the cell with its jaws and then
pumps it out clean. Cilia and mastax are equally char-
acteristic of rotifers and both keep moving as long as the
animal lives. On the moving rotifer the "foot" projects out
from behind and would be far better named the tail; it secretes
the glue by which the rotifer attaches itself to plants or often
to the backs of little crustaceans. Only female rotifers are
ordinarily seen and only in them is the characteristic mastax
present (Fig. loi). Males are extremely minute; in some
species of rotifers the eggs develop without fertilization.
Males have not been found and it is pretty certain that they
do not exist at all.

Habits, resistance to cold and drought. — Rotifers can live
through great extremes of cold and drought. In the fall they
produce tough shells and lie dormant in them through the
winter months, hatching in spring into the individuals which
carry on the race. Some rotifers, Philodinidce (Fig. lOO, i),
are dried up, often through long droughts, but are able to"
keep life going at such a low rate that they can survive and
resume their normal living after the crisis is over. They
can also regain their activity after being frozen into ice for
long periods.

Fig. 102. — The case-building rotifer, Melicerta: i,
animal and case; 2, a cluster of cases on lily pad.
Visible with hand-lens. ( i , from Ward and Whipple.)

129

FIELD BOOK OF PONDS AND STREAMS

There are distinct societies of rotifers; in the open surface
water there is a host of minute transparent ones, the plankton
rotifers, in the plant-filled shallows near shore is another great
company of them which live in the ooze and on the stems and
leaves of plants. The agile, swift-moving rotifers feed upon
microscopic animals; the largely slower ones are vegetarians.
Many of them eat out the cells of filamentous algse, and green
Spirogyra mats are usually full of them.

One of the few rotifers visible to the naked eye is Melicerta
(Fig. 102) which builds itself a case by cementing together
little brown pellets which can be clearly seen through a good
hand-lens. Melicerta lives on the under sides of lily-pads
(Fig. 18) and dozens of them can be found upon almost any
branch of horn wort or water milfoil (PI. IV).

130

CHAPTER X

BRYOZOANS

Bryozoa (or Polyzoa)

Form and habits of bryozoans. — Bryozoans look so much
like moss that they have long been called moss animals or
Bryozoa. Some species live in colonies growing plant-like in
beds (PL VII) made up of hundreds or thousands of in-
dividuals (zooids) and to the naked eye they appear like deli-
cate stiffened threads; in others these animals are covered
with a limy crust, and in a few others like Pectinatella (Fig.
107) they are embedded in the surface of solid masses of jelly.
In any case, what we see when we pull the colonies from the
water are only skeletons or some kind of protecting covers,
in which the animals themselves are entirely hidden. The
individual animals are minute and visible only with a hand-
lens. When undisturbed they constantly rotate their head-
like lophophores in the tops of their tubes, or stretch them
from pores in the surrounding jelly; but at" the slightest jar
they snap them down, leaving no sign of life behind them.
But if a colony or even a fragment of one is allowed to rest
quietly in a dish of water for a few minutes, heads will all
rear up again, swinging and nodding back and forth as before.
The mouth of each animal is in the center of a circular or
horseshoe-shaped wreath of tentacles, this whole "head"
region being called the lophophore (Fig. 103). Each tentacle
is covered with cilia which wave toward the mouth, whirling
along whatever particles get into the current.

131

FIELD BOOK OF PONDS AND STREAMS

The food tube of bryozoans is a U-shaped canal, with the
anus opening near the mouth, either just inside or just outside
of the circlet of tentacles (Fig. 103). Below the tentacles the
body is very flexible and provided with muscles by which the

Fig. 103. — Individual animals of Plumatella: i,
lophophore with tentacles expanded; 2, with ten-
tacles retracted within the zooecium; 3, food tube;
4, anus; 5, developing statoblast.

animals can pull themselves, tentacles and all, into their
shell-like coverings, the zooecia, or into surrounding jelly.
No one who has witnessed a sudden disappearance of these
animal gardens before his eyes can doubt its efficiency in
protecting them against nibbling enemies.

The individual bryozoans which start a new colony in
spring are themselv^es produced either from sex cells, or from
winter buds called statoblasts (Fig. 103), which are very
similar to the gemmules of sponges. Like hydras the fresh

132

BRYOZOANS

water bryozoans have a multitude of relatives in the sea
whence they originally came. Their ancestors slowly mi-
grated up the brooks and rivers, or were carried inland by
animals, encountering ups and downs of temperature and
droughts which they had never met in the ocean. Nearly all
fresh water bryozoans have drought- and cold-resistant
buds, the statoblasts, each capable of forming a new colony.
They are groups of cells which form within the body
of an individual bryozoan and are finally set free in the
water after the animal has died and its hard outer covering
has broken into pieces. Often this does not occur until late
winter, although earlier in the year the current may wash
away everything which remains of a colony, statoblasts and
all. Some statoblasts are enclosed in tough cushions which
buoy them up like life-preservers, and armed with hooks
which anchor them to twigs and trash (Fig. 107). Thus
armed they are carried hither and yon by water and animals,
especially by water birds which transport them over long
distances into new regions. They usually hatch out in the
spring; that they are important safeguards against drought
as well as cold is suggested by the fact that some Brazilian
bryozoans form statoblasts although they have no winter to
endure. They achieve other ends, such as distribution, quite
as important to the animal as protection against cold.

Habitat. — Bryozoans live in all kinds of fresh water, in
stagnant pools, ponds, and rushing streams. They form
delicate traceries on the undersides of flattened stones
(PI. VII), or grow vine-like on logs and boards which have
long lain in the water. Furry colonies of Cristatella (Fig.
108) grow beneath lily pads in quiet coves, masses of Pecti-
natella (Fig. 107) hang from submerged twigs. The latter
and other bryozoans are common in reservoirs.

Food. — They feed upon microscopic organisms, chiefly dia-
toms (PI. IV).

Aquarium study and collecting. — Quiet water bryozoans will

133

FIELD BOOK OF PONDS AND STREAMS

' live for a few days in an aquarium especially if provided with
water from their own pond. Bryozoan colonies are beautiful
with their nodding lophophores and waving tentacles and the
tentacle-wreathed heads of Cristatella look like rose colored
fountains.

Bryozoans cannot be preserved outstretched unless they are
put into an anesthetic (p. 41) like chloretone, before the
alcohol is poured over them. The branching tubes of Pluma-
tella keep well in alcohol ; but the jelly masses of Pectinatella
and Cristatella shrink into sorry looking remnants.

Identification. — Bryozoans are small and their classification
is necessarily based upon microscopic structures. Table of
the genera of bryozoans described here; modified from Pratt
(see Bibliography, p. 413):

I. Lophophore circular. Order GymnolcBtnata (mouth not
covered).

Family Paludicellidcs

Colonies delicate and vinelike, on stones and sticks in
ponds and slow streams.

Fig. 104. — Paludicella ehrenhergii: i, colony; 2,
branch enlarged.

Paludicella ehrenhergii. — The colony is partly creeping
and partly erect, made up of minute club-shaped animals
arranged tandem-wise in the branches (Fig. 104). The
statoblasts are oval, ringed with a bluish purple band. Creep-

134

BRYOZOANS

ing over stones in ponds and slow streams, sometimes in water
pipes; widely distributed.

Occurrence. — May-August.

2. Lophophore oval, or horseshoe-shaped. Order Phy-
lactomcemata (mouth covered).

a, Colony branched, statoblasts without hooks.

Family Fredericellidcs

Colonies branching or forming dense clumps, on stones and
sticks.

Fig. 105. — Fredericella sultana: 1, colony; 2,
statoblast.

Fredericella sultana. — Colony partly creeping and partly
erect with antler-like branches, sometimes forming dense
clumps (Fig. 105). On the undersides of stones and sticks
usually in dark places in ponds and streams.

Occurrence. — Common and widely distributed. May-
August.

Family Pliimatellidce

Colonies of cylindrical tubes either creeping or forming
massive clumps.

Plumatella. — Colony made up of brownish or transparent
branching tubes which trail vinelike or grow in bushy clumps
(Fig. 106). Statoblasts without hooks, sometimes oval, some-
times irregular in shape (Fig. 106). In a variety of places,
ponds, streams, water pipes, reservoir sluiceways, preferring

135

PI. VII. — I, Vinelike colony of the bryozoan, Plumatella, on
the underside of a stone ; the heads are white and the homy
tubes very dark. 2, Half inch of stone surface covered with
the protozoan Vorticella; the blurred white spots are the
moving animals p. 57.

Photo, by A. H. Morgan

PLATE VII

BRYOZOANS

Fig. io6. — Plnmatella polymorpha: i, colony; 2,
statoblast.

darkness. This is the commonest genus of bryozoans, some-
times so abundant in waterways that it has to be removed
with shovels.

Occurrence. — Widely distributed as far west as Montana.
July-August.

b, Colony massive, secreting a gelatinous base.

Family Cristatellidce

Colonies in compact groups in large spherical masses or flat
and rug-like.

Pectinatella. — The colonies are made up of animals clus-
tered on the surface of large masses of jelly which adhere to the

Fig. 107. — Pectinatella r^iagnifica: i, colony; 2,
statoblast.

137

FIELD BOOK OF PONDS AND STREAMS

walls of reservoirs and hang from twigs and water plants.
They become covered with algae and look like green grape-
fruit. Each rosette-like cluster constitutes one group. The
central jelly mass is made larger as the number of animals
increases. Toward fall thousands of statoblasts form, and are
gradually washed from the jelly surface as the colonies die.
They are banded by air-filled cushions and armed with a
single row of hooks which catch upon everything with which
they come in contact. They float like life-preservers on the
surface, and are often piled up in thin brown streaks along
the shore line.

Occurrence. — Common. Northeastern states to Illinois and
Michigan. August-October.

Fig. io8. — Cristatella miicedo: i, coiony; 2,
statoblast.

Cristatella mucedo. — Colony oval, rug-like, i to 2 inches
long on the undersides of leaves, especially lily pads (Fig. 108).
Toward autumn they grow longer and one colony may be
fused with another, giving the effect of a winding, branching
mat. When collected the animals will begin to wave their
tentacles as soon as the water is quiet; looking down upon
their hundreds of waving tentacles is like peering into mini-
ature gardens of translucent flowers.

Occurrence. — In quiet waters. Northeastern states and
Canada to Illinois. Common in Massachusetts. May-
August.

138

CHAPTER XI

THREADWORMS, HAIRWORMS, AND BRISTLE-
WORMS

Nematoda and Oligochaeta

Similarity of worms and midge larvae. — All are not worms
which wriggle; nowhere is this more true than in the mucky-
trash of pond shallows and the weed-grown side-waters of
streams where thousands of insect larvae, almost all of them
midges (p. 291), abound in close company with true thread-
worms or nematodes and bristleworms or oligochaetes.' All
of these are about the same length, mostly under a quarter of
an inch; to the naked eye they look alike, but if they are
examined with a hand-lens their differences will at once appear
(Fig. 109). The midge larvse have distinct heads, segmented
and almost hairless bodies, usually two fleshy prolegs near the
head and two at the rear; such prolegs occur along the abdo-
men of any common caterpillar. These are never found upon
worms. The nematodes are as slender as "midge larvae but
they have no heads, their bodies are unsegmented and without
an appendage of any kind. Most fresh water oligochaetes
are either little transparent bristly worms or small aquatic
earthworms easily recognized as such. They have no heads
and their bodies are divided into segments bearing homy
bristles that are used as feet. The midge larvae along with
the nematodes and the smaller oligochaete worms constitute
a great host of minute animals which are constantly devouring
plant tissues, especially soft ones, continually cleaning up

139

FIELD BOOK OF PONDS AND STREAMS

the refuse in the water and in turn becoming the food of larger
insects and young fishes. Except for the aquatic earthworm
they are all small animals; few are more than an inch or two
long, most of them less than half an inch; many are

Fig. 109. — I, nematode worm; 2, oligochaete
worm; 3, midge (chironomid) larv^a. (i, after Jagers-
kiold.)

microscopic. Although their size is insignificant their num-
bers are so enormous that they play an important and con-
structive part in water life.

Threadworms — Nematoda

Form and habits of nematodes. — The threadworms are slen-
der, strikingly smooth, unsegmented worms, seldom more
than a few millimeters long, very often microscopic. They
are almost inconceivably abundant in pond and stream and
ocean as well as in the soil. Great numbers of them live in
the bodies of aquatic mollusks, crustaceans, and worms,

140

THREADWORMS, HAIRWORMS, BRISTLEWORMS

in addition to the swarms which inhabit the bottom mud,
the surfaces of plants, and everything else in the water.
They are constantly moving through its lower levels and even
city tap water sometimes contains them. Although many
of them are parasites and their ranks include the well-known
hookworm, there are also great numbers of them which are
harmless and free-living.

Nematodes are very active, constantly lashing their bodies
to and fro ; this habit and their smoothness and small size will
usually identify them (Fig. 109, i). The mouth is at the
blunt end of the body; the other end is pointed. Aquatic
members of this group are uniformly minute and difficult to
distinguish, except the allied "hair-snakes" or Gordiacea
which may be a foot or more long.

Hairworms — Gordiacea

Form and habits of hairworms. — Although hairworms are
generally classed as allies of the nematodes they are in many
ways so different from them that they cannot be considered as
very closely related.

Hairsnakes or wireworms lie like twisted roots or loose-
coiled wire, on the bottom of brooks, springs, ponds, troughs,
and rain-barrels. They look like coarse horse-hairs, and
about them clings the well-known story that a hair will "turn
to life" if you leave it in water over night. Their bodies are
entirely covered with a thin layer of hortiy brown chitin,
which stiffens them so that in their slow coiling and uncoiling
they seem to be so much living wire. The front end of the
body tapers to a point but the rear end is split into two or three
parts, the number varying in the two sexes and in different
species (Fig. no).

The adult hairworms that live in the water are a foot or
two long (Fig. no). They lie on the brook bottom, often
singly but sometimes a half dozen are twisted together like a
snarl of twine. They lay their eggs in long strings hung upon

141

FIELD BOOK OF PONDS AND STREAMS

submerged water plants ; these later break up into short pieces
from a fraction of an inch to an inch long.

Although the life histories of many hairworms are unknown,
those of certain species have been studied and the main facts
discovered. In Gorditis rohtistus, the egg hatches into a
minute larva which goes swimming about in the open water
and after a time drops to the bottom and bores its way into
any animal which it can reach. Hundreds of these young
hairworms squirm over the pond bottom, most of them are
probably lost, yet many of them manage to get inside the
bodies of aquatic insects. A few of them wriggle out of the
water and onto the wet soil of the shore, and are there eaten
by grasshoppers which come to the water's edge in search of
food. Occasionally they are eaten by crickets; both kinds of
insects take animal as well as vegetable food. Within a grass-
hopper the hairworm grows, finally reaching maturity.
When thus fullgrown its problem is to reach the water again
and if the grasshopper frequents the water's edge at this
time, the fullgrown hairworm will burrow out of its body.
Whether it is influenced by the moisture is not known but this
seems probable. Once in the water the hairworms mate and
lay eggs that hatch into larvae which begin the cycle all over
again. Obviously but few hairworms which enter the bodies
of grasshoppers ever get back to the water. Most of them
must perish because the grasshoppers are not about the water
at the right time or more often fail to go near it at all. Yet
this and other species of hairworms produce so many eggs
that the race is kept going in spite of the great mortality
which befalls its members.

Two common hairworms. — Two of the most widely dis-
tributed hairworms are Paragordius varius and Gordius villoti
first called G. aquaticus by Montgomery; these are common
through most of the United States (Fig. no). Males of
P. varius are nearly 14 inches long, over 2 inches longer and
more slender than the female, the hind end of the body is bi-

142

THREADWORMS, HAIRWORMS, BRISTLEWORMS

lobed in the male, and tri-lobed in the female (Fig. no).
Their larvae have been found in two species of crickets.
The males of G. villoti are up to 26 inches long and the females

Fig. no. — Adult or water stage of hairworms:
I, Paragordius varies, side view of head; 2, bi-lobed
tail of male; 3, tri-lobed tail of female; 4, Gordius
villoti, head of male; 5, tail of male. (Montgomery.
From Ward and Whipple.)

are as long or longer. The tail is bluntly bi-lobed in the male
but blunt and single in the female (Fig. no). The larvas
live in various species of grasshoppers.

Bristleworms — Oligochcsta

Form and habits of bristleworms. — The fresh water bristle-
worms or oligoch^tes are either bristle-bearing worms about
half an inch long, or small aquatic earthworms easily recog-
nized as such. Their bodies are segmented and like the
leeches they belong to the great Phylum Annelida, which
contains all of the annulate or "ringed" worms. They
are built like earthworms and behave like them, overturning

143

FIELD BOOK OF PONDS AND STREAMS

the ooze of pond bottoms as thoroughly as earthworms over-
turn the topsoil of the land. Their slender, cylindrical
bodies are divided into segments set off on the inside by
muscular partitions, and on the outside by clearly defined
constrictions. They have no fleshy outgrowths along the
sides of the body, and no tentacles such as are found on their
relatives, the clamworms and the tubeworms of the seashore.
Their only appendages are the setae — chitinous rods which
prick through the skin, and are borne in varying numbers
upon their segments. In the common earthworm, Lumbricus
terrestris, such setae can be pulled down into the skin so that
they are partly concealed, and can be felt only when the worm
is stretched out at full length. All the little fresh water
oligochaetes, especially the family Naidce, have such con-
spicuous setae that the whole group of them are called bristle-
worms; many are transparent. Common types are Dero
(Fig. 113), which makes a floating tube from bits of plant
stems, and other naids (Naidce) which live among the latticed
branches of floating algse. Another family, the TuhicidcE,
commonly called "bloodworms," are colored blood-red and
are very active tube-builders on the bottom mud.

Habitat. — Bristleworms frequent the still water of coves,
and stagnant, muddy, or marshy pools, where submerged and
decaying vegetation is plentiful. Many species hide on
plants in the society of snails, planarians, caddis worms,
and hundreds of midge lar\^as; the mud of polluted waters is
often literally astir with them (Fig. 19). They can live
with but little oxygen. Tubifex have been taken from the
depths of Lake Mendota, Wisconsin, in waters which are low
in oxygen for three months at a time.

Food. — ]\Iost oligochaetes live on decayed organic matter,
especially plants; they are constantly cleaning up the pools
and they are largely responsible for the quick disappearance
of dying algal mats (p. 50) in the fall. Charles Darwin's
famous "Vegetable Mold and Earthworms" portrays how the

144

THREADWORMS, HAIRWORMS, BRISTLEWORMS

surface of the earth is being continually passed through the
bodies of earthworms, how they have literally overturned it
again and again. Just as important work is done by their
fresh water allies. The little red Tubifex (Fig. 114) dig their
heads an inch or more down into the bottom mud, and feed
there in a layer containing but little oxygen, and where but
for them decomposition would go on ver}^ slowly. But as
they feed, the waste matter from their bodies is cast out from
the ends projecting above the mud and thus they make a
constant overturn of the mud very like the other one con-
tinually being made on land.

Collecting and aquarium study. — Hundreds of threadworms
and bristleworms can be found by simply rinsing freshly
gathered alg£e and water plants in a dish of clean water.
Those which live on the bottom can be collected in large
numbers by screening mud through a fine-meshed net or
sieve (p. 29).

Despite their importance in the economy of nature, bristle-
worms are not interesting to the general collector. They
are too small to be seen easily and their features are mono-
tonous when visible; their chief interest lies in their works.

Identification. — In most of these worms only the most prom-
inent structures can be seen with a hand-lens. A few of the
best known forms are here figured.

Fig. III. — Nats, one of the commonest bristle-
worms.

Nais. — There are several species of these transparent little
worms (Fig. iii). They are all similar, some of their setee

143

FIELD BOOK OF PONDS AND STREAMS

are short, others long and hairlike; new individuals are pro-
duced by budding. They are very common, in mud or on
plants, in standing or flowing water.

Fig. 112. — ChcEtogaster diaphanus, a common
bristleworm which feeds upon cladocerans.

Chaetogaster. — ChcBtogaster diaphanus (Fig. 112) is a half
inch long, much longer than most bristleworms, and feeds on
little crustaceans, especially the cladocerans (p. 164) Chydorus
and Sphcericus.

r,-.- ^ ' ' ■ '_ I I I I I M I I I I I r I I 1 I I '' ''''*' ' " -j:^
^^■''' I I ■ I I 1 1 I I I M 1 1 I I I I I I I I I I I 1 I 1 1 niT^^''^^

Fig. 113. — Dero. (Walton. From Pratt.)

Dero. — The lively little Dero, hardly a quarter of an inch
long, slips in and out of its tube or changes ends within it.
It is common on floating leaves from lily-pads to duckweed
(Fig. 113).

Fig. 114. — Tubifex tubifex, tube-building worms
with their heads in the mud, and tails pointed
upward. (From Needham.)

146

THREADWORMS, HAIRWORMS, BRISTLEWORMS

Tubifex. — These are slender, red or brownish worms about
an inch and a half long, living in tubes with their tails sticking
up above the surface of the surrounding mud (Fig. 114).
They often form reddish patches on the mud, which in close
view look like waving fringes due to the constant motion of
the tails. Tubifex depends on abundant decaying organic
matter, needing only a moderate amount of oxygen.

147

CHAPTER XII
LEECHES
Hirudinea

Leeches possess much more beauty and interest than their
reputation credits them with. IMost of them are marked with
concealing colors and patterns, browns, greens, and blacks,
picturing upon them the broken shadows and water-soaked
leaves of their natural background and hiding them in it. They
are sensitive to the slightest vibration of the water, to shadows
passing over them, and to small changes in the flavor of the
water around them. Their whole set up is one of exquisite
efficiency for their mode of living.

Form and habits of leeches. — The external features most
essential to a leech are the strong muscular suckers at each
end of its body and the sucking mouth which may or may not
be armed with jaws (Fig. 115). Leeches are segmented worms
like bristleworms and common earthworms and belong to the
Phylum Annelida. Each segment of the body is creased by
two to sixteen superficial wrinkles. These are not easy to dis-
tinguish from the true furrows which separate the segments,
especially since the number of these superficial rings varies in
different parts of the body, there being more in the middle
segments and fewer in those near each end of the animal (Fig.

115)-

Leeches are hermaphroditic, and like the earthworms, pairs
of animals mate even though each one has complete male and
female organs within its own body; thus the eggs of one ani-

148

LEECHES

mal are fertilized by the sperm cells of another. They lay
their eggs in spring and summer, some species continuing to
produce them for five or six months at a stretch. The eggs of
all leeches except the family GlossiphonidcB are surrounded by a
homy capsule or cocoon, sometimes with several eggs in one
case, and glued to stones, plants, or trash, or buried in damp

Fig. 115. — Diagrams of a leech: i, dorsal side
showing the eyes, segments numbered above; 2,
ventral side showing the mouth opening and the
clinging suckers. (From Moore, after Nachtrieb.)

earth. But the family GlossiphonidcB carry their eggs in cap-
sules attached to their ventral sides; there the young ones
hatch out and cling to their parent with then- heads hanging
free (Fig. 118).

Leeches are easily recognized. Their habits are well known
and their medical use is of such long standing that the phrase
"stick like a leech" has been included in the dictionaries. If
one only knows one kind of leech it is easy to recognize others.
Leeches are nearly all aquatic; only a few live on land. They
are curiously varied in their eating habits: a single leech may
feast on snail-meat at one meal and suck turtle blood at its
next one. Those of the same species will sometimes be found

149

FIELD BOOK OF PONDS AND STREAMS

feeding on snails or insect larvae, and again clamped to the
bod}' of a frog and lustily sucking its blood. As a group they
appear to be wavering on the edge of parasitism, but not
wholly committed to it, and while certain species are perma-
nent parasites others are only predatory.

They are acutely sensitive to vibrations in the water and
to even the smallest amount of any substance dissolved in it.
If one presses one's finger against the bottom of a dish contain-
ing leeches, they will at once begin to creep around, restlessly
exploring the whole surface of the dish and if they happen to
pass over the finger print, their agitation makes it quite evi-
dent that they detect its odor. They are also quickly excited by
the movements of water in a pond. If either cattle or persons
wade into a pond inhabited by the American medicinal leeches,
Macrobdella decora (Fig. 119), they will soon swim out into the
open water and gather about the intruders, finally attaching
themselves to their legs. That they do not rely wholly upon
an odor of flesh is shown by the fact that they will attach
themselves to rubber boots almost as readily as to bare legs.
Wading into leech-infected ponds either with or without boots
is a good way to collect them. Leeches are also very sensitive
to light and in different species there may be one or several
pairs of eyes on the head segments as well as a circlet of light-
perceiving organs in each segment (Fig. 115).

Leech bites. — The only American blood-sucking leeches
belong to the genus Macrobdella; the well-known blood-sucker
of ponds and swimming pools is Macrobdella decora (Fig. 119).
Our other blood-sucking leech is the European medicinal leech
Hirudo medicinalis. The latter was imported from Europe for
blood-letting, and has become established in some regions of
New York. It is about 4 inches long, usually greenish colored
on its dorsal side with four to six brown stripes. Although
most leeches are not thorough-going blood-suckers they are all
more or less bloodthirsty. The structures which make them
such successful blood-suckers are their toothed jaws and their

150

LEECHES

suction bulb pharynx or throat cavity (Fig. ii6). When a
blood-sucking leech finds a satisfying skin surface it attaches
its hind sucker and swings its head end about, exploring the
region. If possible it selects a spot where the skin is broken
or is particularly well supplied with blood. It then presses
down its anterior sucker, pushes its three jaws into the flesh
and makes a wound which is at first perfectly painless, but
ma}' later itch intensely. As the jaws enter the flesh, a small
amount of hirudin, the leech's saliva, pours into the wound and
mixes with the blood. Hirudin acts precisely like mosquito
saliva, preventing coagulation of the blood and keeping it thin
so that it can be easily sucked up. Like a mosquito bite the
leech bite will itch worse if the leech is removed soon after it
makes the wound ; but there will be almost no itching if it can
keep on sucking and finishes its meal. During the first part
of the meal the irritating hirudin fills the wound, but near the
completion it has been sucked out. An American medicinal
leech will take about two and a half times its own weight in
blood, which amounts to about half an ounce. This is possi-
ble because the fluid part of the blood is drawn off through the
kidneys of the leech even while it continues to suck from the
wound. Leeches produce some good preservative for their
food for it will keep in their stomachs not used up for nearly a
year. They have been kept in aquaria without food for fifteen
months. Leech bites are not dangerous to human beings ex-
cept through accidental infection of the wound, or in the rare
case of a "natural blee^der, " suffering from haemophilia, when
persistent hemorrhage will follow the bite. Leeches often
attack frogs and turtles in such numbers that they literally
suck the life blood out of them but painted turtles carry
three or four of them without seeming to feel any ill effects.

Habitat. — Leeches abound in ponds, especially those of the
northern states; a few live on stones and boards in swift
streams, but most of them prefer quiet water. Sluggish ditches
swarm with them. The writer attended a country school near

151

FIELD BOOK OF PONDS AND STREAMS

which there was such a ditch, and one of our charming pas-
times was that of capturing leeches and "putting them down "
each other's necks. Many of the family Glossiphonida (p.
154) are partial parasites, part of the time clinging to the thin
skin behind the legs of turtles and to the bodies of frogs and
salamanders, and part of the time foraging for snails and in-
sects over leaves and submerged trash.

Food. — Most leeches will suck blood, if it is available, but
even the good blood-sucker, Macrobdella, feeds upon worms
and larvae in its youth. When fullgrown it lives mainly on
vertebrate blood, preferably human or cattle blood, but lack-
ing these it will satisfy itself with frogs, turtles, and tadpoles.
Some species feed upon worms and snails ; a few are cannibals,
and others are scavengers on dead animals.

Associates. — No ver>^ definite information is available con-
cerning the enemies of leeches, but carnivorous fishes — trout,
sunfish, yellow perch, and black bass — are known to be im-
portant consumers, as well as various wading birds.

Collecting, aquarium study. — Leeches are easily collected
and those from quiet water can be kept indefinitely in aquaria.
If they are found sticking to boards it is best to slide a knife
under them, then let them drop into the collecting dish. They

Fig. 116. — Mouth regions of leeches showing: i,
the mouth which is but a small hole in the oral
sucker; 2, the large mouth occupying the whole
cavity of the sucker.

152

LEECHES

are easy to feed, needing only one meal of ground-up meat,
beef-liver, earthworms or snail-meat once in a few weeks.
When hungry they are very sensitive, and if one even moves
one's hand over a dish of hungry leeches so that its shadow
falls across them, they will at once begin swinging their heads
about exploring for food.

Identification. — Table of the families of leeches represented
here, modified from Moore's key to North American fresh
water leeches (see Bibliography, p. 414).

1. Mouth a small pore in oral sucker from which a mus-
cular proboscis may be protruded ; no jaws.

Suborder RhyncohdellcB.

Body not divided into two regions; usually much
flattened; eyes near median line; typically each
segment contains 3 rings; eggs within capsules and
young being fixed to the mother's body.

Family Glossiphonidce, p.- 154.

Body divided into a narrow anterior and a wider
posterior region ; little depressed ; eyes when present
usually well separated; chiefly parasites attached to
the fins and gills of fishes. No representative is
included here.

Family Ichthyobdellidce.

2. Mouth large, occupying entire cavity of sucker;
pharynx not forming a proboscis; jaws often present.

Suborder GnathobdellcB.

Eyes typically five pairs on segments II-VI; com-
plete segments five-ringed; toothed jaws usually
present.

Family Hirudinidce, p. 155.

Eyes three or four pairs (rarely absent), usually
one or two pairs on II and two pairs at sides of
mouth on IV; no jaws. Predacious.

Family HerpobdellidcB, p. 156.
153

FIELD BOOK OF PONDS AND STREAMS

Family Glossiphonida

Several genera and many species live in shallow water among
plants or under stones, or attached to fishes, salamanders,
frogs and turtles. They are poor swimmers but good creepers.
When disturbed they roll up into balls and drop to the bottom.
They carry their eggs and young on the ventral side of the
body, undulating their bodies in order to secure more oxygen
for them (Fig. ii8). When carrying a large family the par-
ent's body is usually humped up a little and its edges are in-
rolled so that the young leeches are well protected.

Fig. 117. — Turtle leech, Plucobdella parasitica:
I, dorsal; 2, ventral.

Turtle leech, Placobdella parasitica. — Placobdella parasitica
is one of the most abundant American leeches, most often
found clinging to the skin at the base of the hind legs of painted
and snapping turtles (Fig. 117). When rearing their young
these leeches leave the turtles and feed on snails and worms.
In early spring before and during the period of reproduction
they gorge themselves with blood ; at other seasons they may
be kept for months without food. The body is broad and
flat, with a smooth surface, greenish colored, striped and
blotched with yellow; one pair of compound eyes.

Length: very large individuals may be 3-4 inches long when
extended.

Glossiphonia complanata. — This is a common leech in run-
ning water, on the undersides of stones where it feeds upon

154

LEECHES

snails and clinging insects. Its body is very flat; its dorsal
surface is mottled, greenish spotted with yellow (Fig. ii8).
The eggs are laid in large gelatinous capsules which are at-

Fig. ii8. — A common brook leech, Glossiphonia
complanata: i, dorsal; 2, with brood of young leeches
attached to ventral side.

tached to the ventral surface where the young are later car-
ried (Fig. 118).

Family Hirudinida

Members of this family live in ponds and swimming holes.
Besides sucking blood they are greedily predacious upon aqua-
tic worms, larvae, insects, and each ether. They are powerful
swimmers, moving through the open water in undulating
curves.

nr

l:>\|{l'ij|lU

Fig. 119. — Blood-sucker, Macrohdella decora: i,
dorsal; 2, ventral.

Common blood-sucker, American medicinal leech, Macro-
bdella decora. — This and closely related species are the widely

155

FIELD BOOK OF PONDS AND STREAMS

distributed common blood-suckers of shallow water (Fig. 119).
It conceals itself under stones, lying in wait for wading animals
which may come into the pool. It attacks fishes, frogs, turtles,
cattle, and man; it also eats larvae, worms, and great numbers
of frogs' eggs.

It is dull green or olive green, with a row of about twenty red
spots through the middle of the back and a row of black spots
near each side ; the lower surface is reddish orange. This leech
is usually about half an inch wide and so flattened that the
edges of its body are sharp, not rounded as they are in the
horse-leech, Hcemopsis (Fig. 120). Length, 3-6 inches.

Fig. 120. — Horse-leech, Hcemopsis marmoratis: i,
dorsal; 2, ventral.

Horse-leech, Haemopsis marmoratis. — The horse-leech
(Fig. 120) lives in the mud by the sides of pools, ditches, and
streams, feeding on aquatic worms and mollusks; whenever it
has a chance it will suck blood from the legs of wading ani-
mals. Much larger related species occur in the lakes and ponds
of the northern states ; other species burrow in the mud.

Its body is smooth and very soft ; the ground color is gener-
ally some shade of olive green, blotched with irregular spots of
lighter grays and darker browns and black. Length, 4 inches.

Family Herpobdellidce

Several genera and species of these worm leeches abound in
ponds and streams under stones and among plants where they

156

LEECHES

feed chiefly on worms, insect larvae, and decayed matter, but
also suck blood.

Fig. 121. — The best known worm leech, Herpo-
bdella punctata: i, dorsal; 2, ventral.

Herpobdella punctata. — This is the largest and best known
memiber of the family, others in the group have similar char-
acteristics (Fig, I2i). The adults are i to 4 inches long and
vary in color from a light chocolate brown to a pure coal black.
They are widely distributed, common in New England, in
small glacial ponds near Woods Hole and in the Charles River.

157

A

\

CHAPTER XIII

CRUSTACEANS

Crustacea

Crustaceans include the lobsters, crabs, and shrimps which
are well known to every one in one way or another. But for
each of these familiar ones there are thousands that are en-
tirely unknown to most persons. They belong to the Arth-
ropoda, the phylum of animals which also includes myriapods,
insects, and the spiders and mites. Many of these are land
animals, such are the millipeds and centipeds, the spiders, and
nearly all of the adult insects. But crustaceans have remained
predominantly aquatic, and their habits and shapes are inter-
locked with the necessities of water life. Fresh water con-
tains only a small part of them ; the majority live in the sea.

Form and habits of crustaceans in general. — With their
man}'' differences all crustaceans still have a similar pattern of
body. They have an outer shell or exoskeleton, which may
be thick and limy as in crayfishes or delicately transparent as
in Daphnia (p. 164) and many other smaller crustaceans. This
is the hardened secretion of skin cells, and is molted and re-
newed as the animal grows, or as it changes from its young to
adult form.

Crustaceans seldom have anything like a neck region, and in
most of them the head is so fused to the thorax that it cannot
be moved at all. Like all other arthropods they have jointed
bodies and jointed appendages, antennae, legs and even
mouth parts being segmented. In the larger forms like the

158

CRUSTACEANS

crayfishes the body segments show most clearly on the abdo-
men (Fig. 122).

f«l9ion

iuoJIut)^ le^s

Fig. 122. — Diagram of the crayfish, a higher crus-
tacean.

The jointed appendages are the most diversified and yet the
most characteristic structures of crustaceans, big or little.
Legs, swimmerets, and mouth parts are all built on a ground
plan so uniform that they can be compared part with .part,
yet they have the most varied functions — feeling, eating, walk-
ing, swimming, and reproduction. Their shapes tell how
their owners live, what the crayfish eats, and how the fairy
shrimp swims. They are good examples of the zoological
saying that the outside of an animal tells where it has been.

Nearly all crustaceans breathe by means of gills; in cray-
fishes these are attached on each side of the thorax, protected
by the carapace, the shell covering the head and thorax, where
water continually flows over and between them (Fig. 122) ; in
fairy shrimps they are on the ventral side of the body (Fig.
123).

The male and female organs are in different individuals
and the young develop from fertilized eggs, but in many
forms, like the common little Cyclops (p. 166), there are periods
and seasons when the young are produced parthenogenetically,
from eggs which have never been fertilized by male cells.

Two main groups of crustaceans. — There are two main

159

FIELD BOOK OF PONDS AND STREAMS

groups of crustaceans; very small ones, the Entomostraca, and
the large ones, the Malacostraca. Among the entomostracans
are the temperamental fairy shrimps, swarms of little "water-
fleas," and a host of similar minute animals; the malacostra-
cans include such larger ones as the crayfishes, scuds, and
sow-bugs.

A great host of crustaceans are microscopic animals. Many
more are just visible with a hand-lens but cannot be recog-
nized with any certainty; and in still others, like the water-
fiea, Daphnia, their general identity can be made out pretty
clearly. Except in considering their general importance in
water life this book does not attempt to deal with things which
are too small to be seen with the naked eye or through a pocket-
lens. The great group of minute crustaceans can only be given
slight consideration, and the largest and commonest have
been chosen in the hope that these may at least usually be the
ones which are found. Habits, food, and associates of crusta-
ceans will be mentioned under separate groups, only the most
important of which are here named.

Identification. — Key to orders of crustaceans described here,
modified from Pratt (see Bibliography, p. 407).

Subclasses of Crustacea

Small, often minute crustaceans without abdominal appen-
dages. I. Entomostraca (p. 161).
Larger crustaceans usually with abdominal appendages.

2, Malacostraca (p. 168).

I. Orders of Entomostraca

Thoracic appendages flattened and leaflike. Phyllopoda
(p. 161), suborders Branchiopoda (p. 161) and Cladocera

(p. 164).
Animals minute; body elongate and segmented with cylindri-
cal thoracic appendages. Copepoda (p. 166).

160

CRUSTACEANS

Animals minute, entirely enclosed in bivalve shells.

Ostracoda (p. i68).

2. Orders of Malacostraca

Carapace absent, body flattened laterally, very often jump-
ing animals. Amphipoda (p. 169).
Carapace absent (Fig. 131), body flattened dorsoventrally.

Isopoda (p. 171).
Carapace present (Fig. 133), covering the entire thorax.

Decapoda (p. 172).

Subclass Entomostraca

Fairy Shrimps, Water-fleas, Copepods, Ostracods

These are small, often minute crustaceans which have no
appendages on the abdomen. The three most important orders
of fresh water entomostracans are the phyllopods, copepods,
and ostracods.

Phyllopods — Phyllopoda

The Order Phyllopoda includes the Suborder Branchiopoda,
the fairy shrimps (p. 163), which are an inch or more long, and
the Suborder Cladocera, the water-fleas (p. 164), which are
minute.

Fairy shrimps, Branchiopoda. — Fairy shrimps are about
an inch long, varicolored, red, blue, green, and bronze. They
are the largest of the entomostracans, distinguished from all
the rest by the leaflike appendages which have given them
the name Phyllopoda or leaf -footed ones (Fig. 123). These
"leaf -feet" are really gill-feet, combined breathing and swim-
ming organs borne on the body segments posterior to the head,
and although they are true respirator}'- organs, they are re-
markable in having "chewing bases" which help manipulate
the food. Fairy shrimps always swim on their backs and the
waving plumes of their gill-feet are the most conspicuous part
of them. The hind part of the body is slender and with-

161

FIELD BOOK OF PONDS AND STREAMS

out appendages but brightly colored by the blood, red with
haemoglobin as it is in fishes. Their backs are so transparent
that it is often possible to see the beating of the long tubular
heart.

In all species of fairy shrimps females appear to be much
more abundant than males, in some kinds no males are known
and the young develop from eggs which have never been fer-
tilized by male cells. IMating fairy shrimps swim about to-
gether, the male holding the female to his ventral side with the
peculiar claspers which are parts of his antennae modified as
mating organs, the most conspicuous features on the face of
the male fair}^ shrimp (Fig. 123, 2). Just behind his gills, on
the eleventh segment of the body, are the tube-like append-
ages by which he transfers the sperm cells to the fem.ale. In
Euhranchipus (Fig. 123, i) the female carries the eggs in her
conspicuous brood-pouches, sometimes until the young
shrimps hatch.

Habitat, season. — Fairy^ shrimps live in small, often tem-
porary ponds, particularly in cold waters, and are widely dis-
tributed over the United States. They swim on their backs
through the ice-cold waters of early spring pools but their
coming is fraught with uncertainty. For five years they may
come round like the seasons, then they may not appear at all
no matter how right the conditions and in spite of the fact
that earlier they have been too common to be appreciated.

While they are active and full of vitality in the spring they
produce resting eggs which fall to the bottom and lie dormant
in mud either wet or dried. These eggs can endure drjang
for long periods ; some even appear to need drjdng before they
will hatch. Eggs of fairy shrimps kept in dried mud are re-
ported to have developed when they were put into water after
a drying period of fourteen years.

Food. — Fairy shrimps live on microscopic organisms — the
protozoans, floating diatoms, and other algae — which popu-
late the open waters of ponds. These are gathered in a sort

162

CRUSTACEANS

of food-trough between the "chewing bases" of the gill-feet
and passed on toward the mouth by their movements.

Associates. — Fairy shrimps have few enemies, for their sea-
son comes before most animals are active and hungry. Wood
frogs and spotted salamanders are laying their eggs then in the
same ponds but neither of these groups has yet come into pos-
session of its regular appetite.

Identification. — Fairy shrimps are entomostracans with
long (about i inch) distinctly segmented bodies, without a
carapace; (Fig. 123) the thoracic appendages are fiat and
leaflike.

closber

_ FiG._ 123. — Fairy shrimp, Eubranchipus vernalis: I,
side view; 2, head of male showing claspers which
hold the female.

A common fairy shrimp, Eubranchipus vernalis.— Like all

fairy shrimps Eubranchipus constantly swims on its back with
its eleven pairs of gill-feet waving above it. Its body is semi-
transparent, stout and large, about an inch long. The large
frontal appendages or claspers of the male (Fig. 123, 2) are
his most conspicuous features. Females can be distinguished
by the absence of claspers and by the presence of an egg-sac
borne on the ventral side of the body.

This and allied species are locally abundant in pools during
late winter and early spring, but live over the summer as rest-
ing eggs. Eastern North America.

163

FIELD BOOK OF PONDS AND STREAMS

Water-fleas, Cladocera. — Water-fleas are minute crusta-
ceans which swarm through the water in amazing numbers
(Fig. 124). Their short bodies are completely covered by a
transparent carapace. By far the largest of them, the beau-
tiful and fierce carnivore, Leptodora, is less than three-quarters

Fig. 124. — Common cladocerans: l, Daphnia; 2,
Bosmina; 3, Simocephalus; 4, Sida; 5, Latona; 6,
Scapholeheris.

of an inch long; the smallest measures scarcely one one-hun-
dredth of an inch. Several even average-sized cladocerans
can be held in one trap of the bladderwort Utricularia (p. 102).
Yet every one of them has ten legs and highly organized sys-
tems for digestion and reproduction and the like. They are
beautifully transparent under a microscope, with every detail
of their structure showing distinctly without any tools or prep-
aration except a glass slide and a drop of water, and they have
long been favorite animals for study. In 1669 the Dutch
naturalist, Swammerdam, described the common water-flea
(Fig. 124) as Piilex aquaticus arhorescens — the water-flea with
the branching arms — and "water-flea" it has remained ever
since.

Cladocerans and copepods (p. 166) are the staple food of
young fishes. Their importance is obviously not due to their

164

CRUSTACEANS

size, but to their enormous reproductive capacity. One water-
flea {Daphnia pulex) produces a brood of eggs every two or
three days and with its descendants it is said to produce
13,000,000,000 in sixty days. Like many other entomos-
tracans, this httle water-flea has two kinds of eggs — thin-
shelled eggs produced all through the summer which de-
velop without fertilization, and thick-shelled eggs produced
in autumn. These autumn eggs are regularly fertilized by
male cells. Their shells are thickened and sometimes pro-
vided with air cells like the statoblasts of the bryozoan, Pec-
tinatella (Fig. 107), and they are finally enclosed in a saddle-
like cover, the ephippium, which forms around them.

Fig. 125. — A water-flea, Ceratodaphnia reticulata,
carr>'ing resting egg in the ephippium.

Ceratodaphnia carries the ephippium about on her back for
some time, but eventually it falls off and drops to the bottom or
the animal dies. Such resting eggs will live through the win-
ter or long droughts, and then develop into daphnids which go
on with routine life again.

There is a large cladoceran population in the open water,
which feeds on floating diatoms and algae of the plankton
(p. 51) and constitutes a large part of plankton society. They
are abundant through the summer, at night feeding close to the
surface of the water and in the daytime dropping to a little
lower level. Cladocerans can easily be seen swarming near
shore and thousands of them can be dipped up in one cup of
water.

165

FIELD BOOK OF PONDS AND STREAMS

Copepods — Copepoda

There is scarcely a pond to be found without copepods. The
Httle water-hoppers of the genus Cyclops, the commonest of all
entomostracans, are in every pond and ditch which offers
them a semblance of habitation. To the naked eye Cyclops is
only a little white speck jerking through the water. It has a
pear-shaped body tapering into a forked tail, a pair of long an-
tennae, outspread like antlers and helping it to skip through
the water, a single eye in the middle of its head, and four pairs
of swimming-feet on the thorax. If it is a female Cyclops
the pair of egg-packets hanging from her sides will be visible
as far as the animal can be seen. The copepods are very uni-
form in their general shape and habits and Cyclops is typical
of them all (Fig. 126).

Fig. 126. — A water-fiea, Cyclops; female carrying
a pair of egg packets.

When they are mating the male Cyclops clasps the female
with his antenna and they swim about together for long
periods during which enough sperm cells to fertilize several
clutches of eggs are transferred to the body of the female.
Like other entomostracans, they produce two kinds of eggs —
summer ones which form in rapid succession and develop

166

CRUSTACEANS

quickly, insuring large additions to the copepod race; and
the resting eggs usually formed in seasons of cold and drought,
which can lie dormant even through years of drying.

Fig. 127. — Common copepods: i , Diaptomus, often
found in spring-pools; 2, Canthocamptus.

Copepods eat as much of as many kinds of food as their
small size will permit. They feed upon microscopic organ-
isms, and they will devour any kind of decayed matter, but
preferably decomposing plant tissue. Those which live
among the plankton (p. 19) on the surface of open water
are apt to be transparent and slender while ^hose which Hve
in the weeds near shore are shorter and often dark colored-
Some species of Diaptomus (Fig. 127) are red, blue or purple.
The greatest numbers of copepods are found from May to
early November.

Aquarium study. — Cyclops is easy to keep in an aquarium
and is very useful there, being a natural food for small animals
such as the brown and green hydras which flourish on it (Fig.
87). The bladderwort, Utricularia, catches large numbers of
them in its traps (p. 102).

167

FIELD BOOK OF PONDS AND STREAMS

O straco ds — Ostracoda

The ostracods have two-valved shells, hinged at the back
like clam shells, between which their slender tails kick rapidly
backward (Fig. 128). Their two shells are held together by
a transverse muscle as they are in clams, essentially the same
in its function as the muscles which we eat as fried scallops.
The ostracods constitute another army of minute crustaceans
averaging only a millimeter in length, and impossible to tell
apart with a simple lens. They are mostly creeping forms

Fig. 128. — Common ostracod, Cypris, often found
in green alga mats: i, side, and 2, dorsal view.

which frequent the sunny protected areas of ponds, and
intense light seems to quicken all their activities. They are
omnivorous scavengers, especially upon decayed vegetation;
few of them live in very clean water. They clamber about
on submerged plants, laying their eggs upon stems and on
the roots of duckweeds (Lemna) ; many live in the soft ooze
of the bottom.

Subclass Malacostraca

Scuds, Shrimps, Crayfishes

The great majority of malacostracans live in salt water.
Many of them are the jointed shell fish well known, at least,
on the dinner plate — the prawns, shrimps, crabs, and lobsters.
Those of the fresh water, the sow-bugs, scuds, and crayfishes,

168

CRUSTACEANS

are but few compared with them. These are in general the
larger fresh water crustaceans, and though some of them
measure but a fraction of an inch, others are more than four
inches long. Different species are very differently shaped,
hardly recognizable as nearly related animals, yet the ground-
plan of their bodies is strikingly similar. In Asellus (Fig. 131)
as well as in a crayfish there are twenty body segments, joined
in various ways along the back, each one bearing a pair of
appendages. Five of these pairs are borne on the head, eight
on the thorax, and seven on the abdomen and they function
as feelers, eating tools, walking-legs, swimming paddles, and
reproductive organs. The male crayfish transfers sperm
cells to the female with the first pair of appendages on the
abdomen; and the female carries her eggs on her swimmerets.
Unlike as these appendages first appear, they prove to be
strikingly similar when they are carefully compared.

Habitat. — Different orders of malacostracans live in differ-
ent places and will be discussed separately. Most of them
prefer small streams and quiet waters, but there are marked
exceptions; they all hide away from the light, and are often
quite unknown in places where they are abundant. Many of
them take to underground life and all but one of the orders
include species which live in caves, several being blind.

Food. — They are omnivorous, but prefer dead and decaying
matter, and hence are very useful scavengers.

Enemies. — Amphipods are eaten by fishes^ birds, and aqua-
tic insects. The "Caledonia shrimp," Gammarus limnceus, is
a favorite food of brook trout.

Scuds — Amphipoda

Amphipods are accomplished water acrobats and can climb,
jump, swim, or glide with equal ease. They are shaped like
fleas with arched backs and narrow bodies, with climbing
legs on the thorax, and swimming and jumping appendages
on the abdomen (Fig. 129).

169

FIELD BOOK OF PONDS AND STREAMS

Hyallela. — This is a very common amphipod in the ponds
of all the eastern states (Fig. 129). In early spring it gathers
in mats of the alga, Spirogyra, with another amphipod,
Gammarus (Fig. 130), feeding on the dead filaments. Embody

Fig. 129. — Amphipod, Hyallela, widely distribut-
ed through the eastern states: i and 2, grasping
legs; 3, walking legs; 4, swimming legs; 5, jumping
legs.

has seen them eating freshly killed snails, tadpoles, and
crushed amphipods of tfeeir own species; and he once found
a dead water-bird, the sora rail, "alive with Hyallelas which
were feeding upon the decomposed flesh."

Hyallelas live well m aquaria so long as they are sup-
plied with living plants — Elodea, Nitella, or Myriophyllum —
and a few dead leaves. There, their mating and feeding
habits can be watched very easily. In mating the male clasps
the female with his gnathopods or grasping legs and swims
about holding her beneath him for a period of several days
until the female escapes by shedding her old shell, but she is
usually captured again after a brief freedom. Hyallelas molt
so slowly that the process can be easily observed especially
through a hand-lens or reading glass. Females maj^ carry
their previous brood of young in their thoracic brood pouches
even during the mating swim. One pair of Hyallela knicker-
bocheri has been known to produce a clutch of about a dozen
and a half eggs 15 times in 152 days.

Length of adult about one half inch.

170

CRUSTACEANS

Gammarus. — Gammarus (Fig. 130) and Hyallela (Fig. 129),
two of the commonest genera of amphipods in the eastern
states, have very similar habits. They can be found in ponds
and streams the year round. They mate and lay eggs from

Fig. 130. — One of the commonest amphipods,
Gammarus.

April to November, producing about 22 eggs every eleven
days. Embody has reckoned that a single pair of Gammarus
fasciatus might have 24,221 progeny in one year. This species
is also easy to keep for observation in an aquarium.
Length one inch.

Isopods or Sow-bugs — Isopoda

These are broad backed, flattened crustaceans which live
among, the bottom trash of pools. They are commonly
represented only by Asellus, which can be found in pools where
there is hardly anything else living.

Fig. 131. — Isopod, Asellus communis: i, dorsal; 2,
ventral, showing egg pouch beneath the thorax.

171

FIELD BOOK OF PONDS AND STREAMS

Asellus crawl over muddy bottoms eating dead leaves and
refuse in pools which appear very unpropitious for animal
life, where they are often the only animals to be found in
winter and very early spring. They are very light on their
seven pairs of feet. From above an Asellus looks like a
miniature armadillo, gray and heavy. Beginning in very
early spring and continuing through the summer they have
a new brood of young every 5 to 6 weeks and the females seem
to be always carrying a brood pouch full of eggs or of young
ones (Fig, 131). Length under one inch.

Crayfishes or Decapods — Decapoda

Except for the southern fresh water prawns, crayfishes are
the only fresh water representatives of this group made widely
known by the edible crabs and lobsters of the sea. Cray-
fishes with their five pairs of legs, the first pair armed with
conspicuous nippers, look and behave like smaller editions
of lobsters. They live in limy regions in quiet streams,
sometimes in rivers, hiding under stones or burrowing into
banksides. They lie in wait for fishes and water insects and
clutch and tear them to pieces with their big pincers ; they also
eat all sorts of dead plant and animal matter. Some species,
Camharus diogenes and limosus, mate in the fall but do not
lay their eggs till spring, but the more common crayfish,
Camharus bartoni, mates and spawns the year round. An
interesting account of crayfish breeding habits is given in the
Ajnerican Naturalist, 1904, by E. A. Andrews, who kept them
(Cambarus limosus) in aquaria the year round. Before laying,
the female hid in a dark corner of the aquarium and assumed
a peculiar tripod-like position with her body held high,
propped up by her tail and outspread claws. Standing thus
poised she patiently cleaned her swimmerets and abdomen,
scraping with the points and combs of her other feet until the
swimmerets and abdomen were as clean as if the shell had
just been shed. Finally she turned over on her back, and lay

172

CRUSTACEANS

Fig. 132. — A female crayfish, showing the eggs
attached to her swimmerets.

prone, while a milky glue gathering upon her abdomen was
stirred and whipped up with her swimmerets (Fig. 132).
Then she tipped her tail forward and her eggs gradually
poured out from the openings in the bases of her third pair
of walking legs onto the ventral side of her body which formed
a glue-lined basket. At the same time she rolled slowly from
side to side until all of the four or five hundred eggs were
firmly stuck to her swimmerets (Fig. 132).

The young hatch in seven or eight weeks, usually about the
middle of Alay, but instead of dropping off into the water
each one takes firm hold of a maternal swimmeret with its
nippers and rides about on it for six or seven days.

Aquarium study. — Crayfish can be kept for long periods in
aquaria properly supplied with a little mud and plenty of

Fig. 133. — Common eastern crayfish, Cambarus
bartoni, showing the smooth shell of the carapace.

173

^

FIELD BOOK OF PONDS AND STREAMS

water plants. They will eat greedily of bits of meat, pieces
of earthworm, and water insects but they should not be fed
up to the demands of their appetites.

Cambarus bartoni. — This is the commonest crayfish in the
eastern states, being found in small quiet streams from Tennes-
see and the Carolinas to Maine. It can be distinguished by
the smooth carapace of both sexes (Fig. 133) and the hooks
on the first pair of abdominal appendages of the male. Length,
3 inches.

Fig. 134. — Spiny crayfish, Cambarus limosus,
:howing spines on the carapace.

Cambarus limosus (C. affinis). — The carapace is spiny in
both sexes and the body is sparsely covered with hairs (Fig.
134). In the male the first pair of abdominal appendages
are straight. Length about 4 inches.

Occurrence. — In rivers and ponds of New York, Pennsyl-
vania to Virginia.

Chimney crayfishes, Cambarus diogenes. — These crayfishes
are real chimney-builders which make burrows two or three
feet deep in the stream banks. They dig out chambers in
the lower parts of these, which fill with water and make safe
retreats. Turrets several inches high are built around the
upper openings of the burrows which may be a foot or more
back from the stream. Length about 4 inches.

Occurrence. — Locally common especially in quiet streams,
east of the Rocky Mountains to the Atlantic Coast.

174

CHAPTER XIV

WATER-MITES

Hydracarina

Fonn.— Water-mites are small, brightly colored relatives
of the spiders. They have eight legs like them and at
first glance their bodies seem to have the same form. How-
ever, those of water-mites are in a single piece (Fig. 135) while
spiders have two distinct sections, a fused head and thorax
and the abdomen. The group of Acarina, or mites, to which
water-mites are related contains many parasites, some of them
associated with such diseases as itch, mange, and spotted
fever.

Most water-mites are brightly colored, dark red, scarlet, or
sometimes orange (PI. X). They are all small, rarely more
than a quarter of an inch long. One of the largest of them,
the bright red Hydrachna (Fig. 137), is about the size of a
small pea. Others are only a little larger than the head of a
pin.

Habits and habitat.— Although they breathe air and run
about on the surface film and over the border plants they can
stay under water for a long time. They live in the side waters
of quiet streams and in still pools where there is water the
year round. There they creep about on mud and sand
bottoms and over the submerged plants and dart through the
water with a peculiar sort of running glide. They are all
carnivorous feeders, and like spiders clutch their prey and
suck the juice from their bodies.

175

FIELD BOOK OF PONDS AND STREAMS

After mating the females lay their eggs in gluey masses on
the undersides of leaves (Fig. i8), in fresh water sponges, on
the gills and mantles of mussels (Fig. 261), and on the bodies
of water insects, especially water striders, on which the bright
red larvae are familiar sights. Newly hatched mites have
but six legs; they molt several times before they finally take
on the shape of the adult.

Season. — Water-mites can be found at all seasons of the
year, even under the ice in winter. Small but gaily conspicuous
ones are abundant in early spring, but the greatest number
appear in late summer and fall. During October and early
November they can be found by dozens in beds of Elodea.

Aquarium study. — The largest water-mites are easily col-
lected with a water-net or dipped up with a big nosed bottle
as they hang motionless from water plants. They usually
live but a short time in aquaria and will stay there only if it
is enclosed by a fine wire screen. If they are to be kept for
study, they should be preserved in small vials of formalin in
the field (p. 41).

Identification. — Table of subfamilies of water-mites (modi-
fied from Pratt) with common representatives.

I . Large red mites with 4 eyes close together on a plate ;
eye plate long and narrow. Lim7iocharince (p. 177)

Fig. 135. — Limnochares aquaticus. (From Ward
and Whipple.)

176

WATER-MITES

Limnochares aquaticus.— Body red, rectangular, about one-
eighth of an inch long (Fig. 135) ; eyes near together on a
long narrow plate. Common on the bottom of ponds where
they walk over the mud and submerged plants; immature
young known as larvee attached to water skaters.

2. Eye plate short, broad and paired, eyes 4, near to-
gether. EylaincR (p. 177)

,„-^^^- 136. — I, Eylais extendens; 2, eye plate.
(From Ward and Whipple.)

Eylais extendens.— Body red, oval, about one-eighth of an
inch long; eyes near together on a paired plate (Fig. 136). In
ponds, where they glide rapidly through the water. Common.

3. Eyes not close together on a plate, but far apart,
pedipalps pincer-like. Hydrachnince (p. 177)

- Hydrachna geographica.— Body dark red with dark red spots
on the back, oval, nearly one-third of an inch long; 4 eyes, 2 on

177

/J

/

FIELD BOOK OF PONDS AND STREAMS

Fig. 137. — Hydraclina geographica. (From Ward
and Whipple.)

each side, sometimes a fifth one in the middle (Fig. 137). In
swamps and ponds, usually common.

4. Eyes not close together on a plate but far apart, pedi-
palps not pincer-like. Hygrohatina.

Several genera and species, members of which are parasitic
in youth or permanently on water insects and on the gills of
fresh water mussels.

178

i

CHAPTER XV

AQUATIC INSECTS

Insecta

Water insects and water plants have several points in com-
mon. Both groups are very limited when compared with the
number of their terrestrial relatives and neither of them to any
extent inhabits deep water nor lives far from shore. In most
aquatic seed plants pollination occurs above the water; most
aquatic insects mate in the air or upon the surface of the water.
Aquatic insects live in the water mainly during their immature
stages and even these show many marks of terrestrial origin.
In aquatic insects, virtually all the adults breathe air and
many of them fly away from the water, returning only to lay
their eggs.

The insects commonly known as aquatic are the stoneflies
or Plecoptera; the mayflies or Ephemerida; the dragonflies and
damselflies or Odonata; the water-bugs or Hemiptera; the net-
winged insects or Neuroptera; the caddis flies^ or Trichoptera;
the moths or Lepidoptera; the beetles or Coleoptera; and the
flies or Diptera. In addition to these there are the spring-
tails, Collembola, which gatherabout the pond-margins, spring-
ing up from the surface film, and a few species of very small
wasplike forms belonging to the order Hymenoptera, not in-
cluded in this book. All of these aquatic forms have the
typical insect structure and during their growth and life
history they go through the same changes of form as their
nearest land relatives.

179

FIELD BOOK OF PONDS AND STREAMS

The outside of an insect. — The skeleton of an insect entirely
covers the outside of its body. It is chitinous or horny, thin
and flexible at the joints, and even thinner over the tips of the

,^''

►*)

Fig. 138. — Diagram of stonefly nymph with legs
of one side removed to show their segments: i, head
with simple and compound eyes; 2, prothorax; 3,
mesothorax; and 4, metathorax with developing
wingpads; 5, abdomen; 6, legs removed (a, coxa; h,
trochanter; c^ femur; <f, tibia; e, tarsi and claws).

palpi and the antennae or ' ' feelers. " It is made of the hardened
fluid secretion of the skin cells beneath it and is molted or
cast off at intervals, a new one being formed beneath it.
Every hair and spine and claw is a part of it and is molted
with it.

All insects are built upon the same plan. This plan can
be easily traced in the stonefly already selected to show a
simple type of insect structure (Needham, Bibliography, p.
416). The body of an insect is divided into three main parts,
head, thorax, and abdomen (Fig. 138).

On the head are the simple and the compound eyes, the
antennae, and the mouth parts. The simple eyes are small and
inconspicuous and it is only the compound eyes which are
usually seen. Antennae vary greatly in length even in dif-
ferent stages in the growth of the same insect, as in the nymph

180

AQUATIC INSECTS

and adult stonefly (Fig. 144). The mouth parts are a labrum
or upper lip, labium or lower lip, and two pairs of jaws, the
mandibles and maxillse, which open and close sidewise. In
the stonefly nymph the labrum is a simple flap hanging for-
ward over the upper jaws (Fig. 139).

Fig. 139. — Mouth-parts of a stonefly nymph seen
from beneath: A. — With labium (i) in place; 2,
maxilla; 3, labrum. B. — With labium removed; i,
maxilla; 2, mandible.

The labium folds upward and covers the maxillae or lower
jaws; it is partly slit through the middle and bears a three-
jointed feeler-like palp upon each side. The upper jaws
or mandibles are single pieces of chitin, saw-toothed at the
tips for biting and chewing. The maxillae are also used in
chewing but are more delicate and each is made up of several
parts including a five- jointed palp. Insects test their food
with their palps before they take it into their mouths, the
hypopharynx or tongue being strongly coated with chitin
and of little use as a sense organ.

Three pairs of legs on the thorax distinguish insects from
all other arthropods, spiders and their kin and the crustaceans;
one or two pairs of wings are also borne there. The thorax
is divided into three parts, prothorax, mesothorax, and meta-
thorax, on each of which is one pair of legs. The first pair
of wings is on the mesothorax and the second pair on the
metathorax. Developing wings or wing-pads of the stone-
fly nymph can be seen on its thorax (Fig. 139). These are

181

FIELD BOOK OF PONDS AND STREAMS

conspicuous on full-grown nymphs of dragonflies, damsel-
flies and mayflies and usually look thick, often black, for a
few days before the adults emerge (PI. XV).

mK

Fig. 140. — Diagram of the principal veins of an
insect wing, showing their types of branching, cross-
veins omitted: C, costa; Sc, sub-costa; R, radius;
M, media; Cu, cubitus; A, anal. (After Needham.)

When the stonefly finally emerges from its nymphal skin
it pulls the fully developed wings from the wing-pads and
unfolds them to the air. They are thin membranous sails
supported by rods of chitin, the veins. Toward the front
edge of the wing the veins are stronger and set more closely
together than they are further back. This strengthens the

> C 5e,

3

Fig. 141. — Front (A) and hind (B) wings of the
stonefly, Perla capitata. The principal veins are
marked by capitals; cross-veins, by small letters.
(After Needham.)

182

AQUATIC INSECTS

edge which cuts the air during flight. There may be many
small cross veins in the wings as there are in mayflies and their
branching is often very complicated but the ground plan is
simple (Fig. 140). There are five veins — costa (C),
subcosta (Sc), radius (R), media (M), and cubitus (Cu), that
strengthen the front and middle section, and three anal (A)
veins stiffening the hindpart of it. Cross veins connect these
main veins and their branches (Fig. 141).

An insect's legs are all built on the same plan. Beginning
where it is attached to the body the leg has two short segments,
the coxa and trochanter, followed by two long ones, the femur
and tibia, which make the greater part of the length of the
leg, and finally there are several (1-5) small segments which
form the tarsus or foot, usually tipped by one or more claws
(Fig. 138).

The insect abdomen is divided into segments, there being
ten in the stonefly; it never bears any true legs though it
may have short fleshy props or prolegs like those on cater-
pillars and the larvae of midges (Fig. 228). Stoneflies and
many other insects have tails or cerci which are many-jointed
like antennas ; in adult mayflies these are a couple of times the
length of the body and seem to help steer during flight (p. 205).

The inside of an insect. — The food tube or alimentary canal
runs from one end of the body to the other; it includes a crop
and a gizzard whose functions are similar to those of birds
and behind which open the Malpighian tubules, the kidney-
like organs of the insect (PI, VIII). Beneath this tube is
the nerve chain and above it is the long tubular heart whose
pulsations can sometimes be seen along the midline of the
backs of newly molted mayfly nymphs.

Insects do not breathe through their mouths as is so often
supposed. All through their bodies there runs an intricate
network of air tubes or tracheas which carry air. In adult
insects like the dragonfly the tracheae open by spiracles along
the sides of the body; in whirligig beetles their openings are

183

PI. VIII. — Insect structures: i, gill of maj^fly, Siphlurus,
showing the branching air-tubes ; 2 , underside of water penny
showing its white, fringed gills; 3, subimago mayfly (a,
oesophagus; h, gas-filled stomach; c, ovary; d, intestine; e,
Malpighian tubules) ; 4, subimago mayfly with alimentary
canal removed {a, muscles; b, nerve chain; c, ovary).

Photo, by A. H. Morgan

PLATE Vm

AQUATIC INSECTS

in chambers kept dry by the wings. Many aquatic nymphs,
stoneflies, mayflies and others have no spiracles but the
tracheae branch out into dehcate sac-Hke out-growths of the
body- wall, forming the tracheal gills (PL VIII). These
tracheal gills are so thin that oxygen can pass through
their walls into the tracheae and thence into the body. Many
mayfly nymphs have leaflike gills in which the tracery of the
trachcce is clearly visible through a hand-lens, sometimes
even to the naked eye (PL XV).

Fig. 142. — Gills of mayfly nymph, Chirotenetes,
those of the right side turned with their under sur-
faces upward.

In dragonfly larvae the lining of the hind intestine is infolded
in delicate frills and flutings traversed with tracheae, thus
forming tracheal gills. These hang into the cavity of the
intestine (rectal chamber) and the nymphs breathe by alter-
nately taking water into it and forcing it out again (PL IX).

How insects grow. — The eggs of water insects have shells
which are often beautifully sculptured and provided with
safety devices. On the eggs of one mayfly, Tricorythus
(Fig. 143), are threads by which they are suspended from
plants out of the mud and where they secure abundant oxygen.
On those of another, Ephemerella rotunda, there are floats
which buoy it up out of the mud (Fig. 143).

Mayfly nymphs and others go through only partial change
of form as they increase in size. They shed their inelastic
outside skeleton or skin soon after hatching and at intervals
through their nymphal lives. After each molt the nymph
grows for a period then sheds its skin again, and in mayflies
this may go on for twenty times or more. When it molts
for the last time in the water it comes forth with a shape

185

y

PL IX. — I. Wing-pad of mayfly nymph; dark lines are
the tracheas; soft gray lines represent the developing veins.
2. Air-tubes or tracheae of a dragonfly nymph in dorsal
view; the alimentary canal lies between the two large
tracheae but is hidden by masses of fat: a, large trachea (con-
nected with spiracles in adult); b, fat; c, tracheae in wall of
intestine.

PLATE IX

AQUATIC INSECTS

changed notably in those structuies which have to do with
reproduction. It has transformed from a nymph to a mature
adult. After this it does not grow larger or ever shed its skin

Fig. 143. — Eggs of mayflies with structures,
threads and floats, by which they are suspended in
the water: i, Tricorythus; 2, Ephemerella rotunda.

again. In mayflies there is a second molt after the winged
form has been attained, a change from the nearly adult sub-
imago to the fully mature imago (PI. XI) but this is an excep-
tion among all insects. The changes of form which the
mayfly or stonefly undergoes during its life are known as
incomplete metamorphosis (Fig. 144).

The change of form between the young insect and the adult
may be far greater than this. A caterpillar hatches out of a
moth egg; it shows no hint of wings, has a wormlike shape, a
great appetite, and is known as a larva. After a period of
eating and growing, it loses its appetite, stops moving about,
moves into a secluded spot, and finally sheds its larval skin.
This discloses a very differently shaped insect with wings and
antennas outlined on its skin which suggest the adult moth.
The moth is now in the pupal stage during which it is made
over, inside and outside. At the end of the pupal stage the
fully formed adult moth comes forth from the pupal skin.
The changes which it has gone through are called complete
metamorphosis (Fig. 145). Incomplete and complete meta-
morphosis both occur in aquatic insects.

187

FIELD BOOK OF PONDS AND STREAMS

Incomplete metamorphosis.— Stages of the insect life — egg,
nymph, and adult.

Stoneflies, mayflies, dragonflies and damselflles, water-bugs.

Fig. 144. — Change of form in incomplete meta-
morphosis: I, stonefly nymph; 2, adult.

Complete metamorphosis. — Stages of the insect life — egg,
larva, pupa, and adult.

Caddis flies, moths, beetles, flies.

Fig. 145. — Change of form in complete metamor-
phosis: I, mosquito larva; 2, pupa; 3, adult.

188

AQUATIC INSECTS

KEY TO THE ORDERS OF IMMATURE AQUATIC
INSECTS. NYMPHS AND LARV^. (AFTER

NEEDHAM)

(Collembola and Hymenoptera not included.)

1 — Larvse with wings developing externally (nymphs) and

no quiescent pupal stage. 2

— Larvce proper, with wings developing internally, and

invisible till the assumption of a quiescent pupal

stage; form more wormlike. 5

2 — With biting mouth parts. 3

— Mouth parts combined into a jointed sucking beak,

which is directed beneath the head backward beneath

the forelegs. Water-bugs, p. 225. Hemiptera

3 — With long slender tails; labium not longer than the head,
and not folded on itself like a hinge. 4

— Tails represented by 3 broad, leaflike respiratory plates
traversed by tracheae, or by small spinous appendages ;
labium when extended much longer than the head; at
rest folded like a hinge, extending between the bases
of the forelegs.

Damselflies and dragonflies, p. 213. Odonata

4 — Gills mainly under the thorax; tarsal claws two; tails
two. Stoneflies, p. 193. Plecoptera

— Gills mainly on the sides of the abdomen; tarsal
claws single; tails generally three.

Mayflies, p. 198. Ephemerida

5 — With jointed thoracic legs. 6

— Without jointed thoracic legs; with abdominal prolegs,

or entirely legless. Flies, p. 282. Diptera

6 — With slender, decurved, piercing mouth parts, half as
long as the body; small larvae, living on fresh water
sponges.

Families HemerobiidcB, Sisyrida, p. 245. Neuroptera
— With biting mouth parts. 7

7 — With a pair of prolegs on the last segment only (except
in Stalls, p. 241, which has a single long median tail-
like process at the end of the abdomen) ; these directed

189

FIELD BOOK OF PONDS AND STREAMS

backward, and armed each with one or two strong
hooks or claws, 8

— Prolegs, when present, on more than one abdominal
segment; if present on the last segment, then not
armed with single or double claws (except in gyrinid
beetle larvse, which have paired lateral abdominal fila-
ments), often entirely wanting. 9

8 — Abdominal segments each with a pair of long, lateral

filaments. Family SialidcB, p. 241. Netiroptera

— Abdominal segments without long, muscular, lateral

filaments, often with minute gill filaments ; cylindrical

larvae, generally living in portable cases.

Caddis flies, p. 247. Trichoptera

9 — With five pairs of prolegs, and no spiracles at the apex

of the abdomen. Moths, p. 257. Lepidoptera

— Generally without prolegs ; never with five pairs of them ;

usually with terminal spiracles ; long, lateral filaments

sometimes present on the abdominal segments.

Beetles, p. 261. Coleoptera

Springtails — Collembola

Wherever the shorelines make little bays of quiet water,
springtails gather in blackish patches on the surface film.
Thousands of them congregate there and if they are disturbed
the company will go up into the air like flying spray, coming
down again a foot or two away. They are so minute, that
they can jump upward like this and come down with all their
force without making more than a dent on the surface film.
Like water striders, though they live on the water surface,
they are thoroughly aerial insects.

All Collembola are minute and none of them has wings.
Many species dwell in damp, shady places on land; one of the
most familiar, the snow-flea, Achorutes socialis, lives on the
snow. Although springtails have six orthodox walking legs,
their unique locomotor apparatus is on the hind end of their
bodies. On the fourth abdominal segment there is a forked

190

AQUATIC INSECTS

tail-piece which the springtail can fold beneath its body and
lock into two little appendages on the under side of the third
abdominal segment (Fig. 146). When it forces its tail-piece
suddenly downward, the springtail is lifted high in the air
as a kangaroo might be if it sat on its tail and snapped it hard
against the ground.

Fig. 146. — Water springtail, Podura aquatica.

Water springtail, Podura aquatica. — This common spring-
tail of slow streams and pools is dull bluish black and although
only one-fifth to one-fourth of an inch long the segments of
its body show very distinctly through a simple lens (Fig.
146). These springtails are exceedingly gregarious and
gather in enormous numbers, m.aking a blue-black band along
the margin of the water. The body surface is difficult to wet
because of the hairs which hold a blanket of air around it.
Springtails probably go to the bottom and hibernate there
through the winter since they are among the earliest spring
arrivals at the surface. They are said to live upon plant
tissues, but their food habits need more study. In Miall's
" Aquaticlnsects " there is a quotation from an account by
the entomologist De Geer, published in 1778. De Geer kept
springtails for a long time in a dish of water and found that
they crawled down to the bottom and lived there several
days at a time. It has been suggested that springtails may
climb down into the water and forage upon submerged plants.

Occurrence. — In still water, along the margins of ponds
and streams. Common and generally distributed through
eastern and central North America. Common October-
November.

191

PI. X. — Summer life in the quiet shallows: i, broad-leaved
arrowhead; 2, white water lily; 3, Elodea; 4, Myriophyllum; 5,
6, 7, dragonfly, Libellula pulchellu (5, nymph; 6, cast
skin of nymph; 7, adult); 8, 9, diving beetle, Dytiscus (8,
larva; 9, adult); 10, adult backswimmer, Notonecta; 11, leaf-
beetle, Donacia; and 12, holes through which Donacia lays
her eggs; 13, whirligig beetle; 14, caddis worm, Tricenodes;
15, water-mite; 16, fresh water sponge green with algas; 17,
nymph of mayfly, Callihatis.

A

/

r. 'A^ i

V

PLATE X

AQUATIC INSECTS

Stoneflies — Plecoptera

Nymphs. — Stonefly nymphs hatch out in the water and hve
there for a year or more before they shed their last nymphal
skins and take to the air. Fullgrown nymphs may be less
than half an inch long like the little black Allocapnias {Cap-
nias) (Fig. 153) or they may even measure 2 inches like
Pteronarcys (Fig. 147). They have flattened bodies, two
segmented filamentous tails (cerci), and tufts of thread-like

Fig. 147.— Nymph of the large stonefly, Ptero-
narcys dorsata; the thoracic gills and the paired
claws are characteristic of stoneflies.

gills. These gills are mainly on the thorax (Fig. 147), at the
bases of the legs, and sometimes on the neck, but they also
occur on the sides and tip of the abdomen. [A few small
species do not have any gills. Stonefly gills are always on
the underparts of the body, never on the back or sides as
they are in mayflies (Fig. 158). All stoneflies have two claws
on each foot ; mayflies have but one claw.

Adults.— Like the fullgrown nymphs the adults vary from
one-half to two inches in length. Like the nymphs, too, they

193

FIELD BOOK OF PONDS AND STREAMS

have biting mouth parts and are dull-colored — dark brown,
yellow, or pale green. Similarly they are squarely built but
their tail filaments are very much shorter than those of the
nymph. They hold their two pairs of wings closely to the
body with the wide hind ones plaited and hidden beneath the
front ones (Fig. 148). They do not fly about very much.

Fig. 148. — Adult stonefiy, Pteronarcys dorsata.

Many species skulk about in any shady place which is near
the water but in contrast to these shade-loving species are
the little black Allocapnias (Capnias) and Capnellas which
run over the dazzling sunlit snow from January to March.

Little is known of the egg-laying habits of stoneflies. When
in captivity, Perla immarginata deposits her eggs loose in the
water. This is probably true of many species since their
eggs are not found in patches on stones and sticks as are
those of caddis flies and some other water insects. Most
adults live only a short time and probably eat little or nothing.

Habits. — With few exceptions stonefiy nymphs live in swift
water, swirling brooks and waterfalls (Fig. 23). They clamber
over the stones, keeping hold by their strong claws, always

194

AQUATIC INSECTS

seeking the dark side of everything. They have a sidling
gait and when the stones on which they Hve are overturned
and exposed to the light they scatter like rats and drop off
the edges into the water.

The adults hide on the under surfaces of the leaves of trees,
falling to the ground if the tree is shaken. Dr. J. G. Needham
writes that he "once found the stout-bodied Acroneuria
pacifica, clinging in numbers to young pine-trees on the steep
slopes of the Yellowstone Canyon, and obtained specimens
very easily by shaking the trees, dashing the stoneflies to the
ground, and picking them up before they had run to cover. "
During their nymphal life of a year or more many species
live on vegetable matter but a few such as Perla will devour
other insects or even turn cannibal.

Associates. — Stonefly nymphs are commonly found on the
same stones with mayflies, the net-building caddis worm,
Hydropsyche, and water pennies (Fig. 23).

Aquarium study. — Stonefly nymphs cannot be kept alive
more than a few hours, and usually not so long as that, with-
out running water. They are dependent on rapid currents
and as soon as they are put in pans of still water they begin
to buck and pump their bodies up and down, thus creating
a circulation over their gills.

Family Pteronarcidae. — ^These are the largest known stone-
flies (Fig. 148). They are vegetable feeders which are found
emerging from streams during May and June. They are
common in creeks and small rivers where they live among the
decayed leaves brought together by the currents. Eastern
states to Tennessee, west to Minnesota and Alaska.

Family Perlidae. — This family includes many of the most
familiar stoneflies. All of the genus Perla have a tuft of fine
filamentous gills about the base of each leg (Fig. 149). Com-
mon in swift streams, the adults emerging through early
spring. Length of nymph, one inch. Eastern states to
Georgia.

195

FIELD BOOK OF PONDS AND STREAMS

Fig. 149. — Nymph of Perla, an early spring stone-
fly.

Chloroperla or Alloperla. — Daintily beautiful, pale greenish
nymphs about a quarter of an inch long, which have no gills
(Fig. 150). The adults which emerge through late spring
into midsummer are daylight fliers which like sunshine.
Generally distributed through North America.

Fig. 150. — Nymph of green stonefly, Chloroperla.

196

AQUATIC INSECTS

Fig. 151. — Nymph of Peltoperla; its gills are
hidden beneath the flaring thorax.

Peltoperla. — In Peltoperla the clusters of thoracic gills are
entirely concealed under the flaring margins of the thoracic
segments (Fig. 151). Fullgrown nymphs are one half inch
long. The genus is generally distributed over North Am-
erica. Emerging in May-June.

Fig. 152. — Nymph and adult of Tceniopteryx
nivalis, a winter stonefly.

197

FIELD BOOK OF PONDS AND STREAMS

Taeniopteryx nivalis. — Both the nymphs and adults are
slender, black or blackish-brown and the nymphs have no
gills (Fig. 152). These are winter stoneflies (PL I), the adults,
first emerging from the water and crawling over the snow in
February, but they are also commonly found through May.
Length one-half inch. Eastern and central states south to
North Carolina.

Fig. 153. — Nymph and adult of AUocapnia
(Capnia) vernalis, an early spring stonefly.

AUocapnia (Capnia) vernalis. — These are blackish stoneflies
usually less than half an inch long. Only one species, AUo-
capnia (Capnia) vernalis (Fig. 153), is found east of the Rocky
JMountains. The adults usually emerge from January to
April. Eastern and central states. Several species of the
very similar genus Capnella are found in northeastern North
America.

Mayflies — Ephemerida {Plectoptera)

Many persons have seen mayflies even though they have
not recognized them as such. They may have watched
g,Teat swarms of "flies" over a lake at twilight, or come upon
dead insects strewn upon the lake shore or beneath street-
lights, or have fished with the artificial bait-flies, many of
which are modeled after ma3^flies.

198

AQUATIC INSECTS

Nymphs. — Mayfly nymphs are of many shapes and sizes;
some have flattened heads and bodies and their sprawling
legs are held akimbo as in Heptagenia. Active runners, like
CallihcEtis, are set high on spindling legs, while the little
creeper, Leptophlehia, almost drags its low slung body. But
all mayfly nymphs agree in having seven pairs of gills on the
abdomen, and with rare exceptions have no gills anywhere
else. They have two or three long slender tail filaments,^ or
set£e, and but a single claw on each foot. Stonefly nymphs,
sometimes confused with mayflies, have two claws on each
foot and nearly all their gills are on the thorax. Their
differently shaped bodies reveal much about the places where
they live and their way of getting a living. Many are well
fitted for particular habitats but are helpless when they are
out of them. Epeorus (PL XV) is so flat and its gills and
claws such efficient hold-fasts that it can cling to a rock no
matter how strong the current, yet it is quite helpless among
slender plant stems where Callihatis is thoroughly at home
(Fig. 158).

Adults. — Mayflies spend nearly all of their lives as nymphs
in the water. During this time they eat a great deal and in
a few weeks, or in the case of some species, in a year or more,
they emerge into the air as subimagos or "duns" with pale
gray wings (PL XI, i). Subimagos soon shed their skins
again and become fully matured imagos or "spinners"
(PL XI, 2). As winged insects their lives last only a few
hours or days at most, during which they do not eat at all.
For a long time the fishermen have called them "duns"
and "spinners." Fishermen of England have given them
other picture names, like "the silver gray," "the evening
spinner." Many of these fishermen have made their own
"dry flies," wrought of silk and fur and feathers like
those described in that most charming of guides, Ronald's
" Fly-Fisher's Entomology."

Adult mayflies are delicately beautiful insects, soft gray,

199

PL XI. — Adult' mayflies: i, First winged stage (subimago)
of CallibcBtis; it has just shed its nymphal skin and is resting
on the surface film of water. 2, Second winged stage (imago)
of Blasturus; it has shed its subimago skin which shows the
dark wing-sacs.

PLATE XI

-

AQUATIC INSECTS

and brown, or pale and translucent, fragile and short-lived,
as their name, Ephemerida, implies. They have large front-
wings and small hind ones except in some very small species
such as Ccenis in which hind wings are altogether absent.
The adults have either two or three tail filaments, which are
much longer than those of the corresponding nymphs. Their
mouth parts are shrunken and useless; so that in the mayfly
countenance the whole mouth region is like a receding chin.
Their legs are weak and little used for walking, the front legs
of the males are long and often held forward with a reception-
line cordiality. Dr. J. G. Needham has aptly named one
mayfly the "white-gloved howdy" (Fig. 159).

As soon as they emerge from the water the subimagos fly
upward to overhanging trees or shrubbery. They do not move
about very much until the mating flight which in some species
occurs almost immediately, in others within a day or two.

The mating flight usually takes place in late afternoon or
twilight. Then hundreds of spinners, mostly males, swing
up and down through the air in a rhythmic dancing flight
over streams or lakes. With their rudder-like tails stiffly
extended they drop downward in swift descents of thirty
feet and more and then bound upward with the lightness of
springing thistledown. Hundreds or even thousands of
them move up and down together. In half ah hour they have
disappeared into the trees as suddenly as they came, or they
are strewn upon the water to become the food of eager fishes.
During this flight a dozen or so from the hundreds of males
mate with the few females which almost immediately lay
their eggs in the water and then die upon its surface.

The little mayflies of the genus Bcetis fly in a low compact
mating swarm and the female literally climbs down into the
water to lay her eggs (PI. XII). The following description
is taken from my notes on her habits.

Flying close to the surface of the water, the insect alighted
on a stone projecting slightly from the water and well pro-

201

PI. XII. — Eggs of mayfly, Batis: i, stone covered with egg-
patches; 2, egg-patches enlarged showing straight edges where
the mayfly stopped laying. Egg patches, one quarter
inch long.

PLATE XII

AQUATIC INSECTS

tected from the force of the current on its downstream side.
She at once walked to the protected side and downward to
the water. First, wrapping her wings about her abdomen,
she made several attempts to immerse her head and thorax.
This appears to be the critical stage in the performance, and
many mayflies are washed away while attempting it. Once
under the water she started on a tour of inspection. This
lasted for several minutes during which she continually
walked to and fro, pausing, feeling the stone with the tip of
her abdomen, and passing on unsatisfied. When she finally
found a suitable place she braced her legs firmly, bending the
end of her abdomen downward and her tail filaments upward.
She then began swinging her whole abdomen from side to
side with a slow pendulum-like motion, at each stroke leaving
an irregular row of minute white eggs adhering to the surface,
the first ones circular and somewhat longer than those which
came later. As the egg mass grew larger she moved forward
a little to allow the eggs to lie in succeeding rows. When her
supply was exhausted she jerked her abdomen upward and
abruptly clambered out of the water.

Habitat and season. — Mayfly nymphs live in clean fresh
waters, flowing rivulets or rivers, tumbling waterfalls or quiet
pools; they -have become adapted to every aquatic situation
except foul water (PI. III). In many ponds they far out-
number all other animals anywhere near their equal in size.

Spring is the mayfly season and the fullgroWn nymphs with
their black wing-pads are abundant from March to late June
and adults are emerging and swarming at this time. Young
nymphs can be found in shallow brooks the year around.

Food. — These nymphs are confirmed vegetarians; their
staple food is the great crop of diatoms and desmids which
makes the golden-green color upon stones of the brook bottom
and covers almost every object in the water (PL IV). Be-
sides this they eat the soft tissues of larger plants either living
or dead.

203

FIELD BOOK OF PONDS AND STREAMS

Associates. — IMayfly nymphs live upon food which is so
abundant that the snails and entomostracans and the few
herbivorous insects which share it with them in no way
menace their supply. Mayfly populations are not kept in
check by lack of food but by the animals which prey upon
them, these being almost ever>' carnivorous inhabitant of the
water, including dragonfly nymphs, water beetles, and young
fishes in enormous numbers. Alayflies are the most important
food of these 3^oung fishes and if some method of breeding
them in captivity could be discovered it would do much to
solve the food problems of fish hatcheries.

Aquarium study and collecting. — Nymphs of quiet waters
are easily kept in aquaria supplied with algae and water plants.
If they are fullgrown they will shed their skins and usually
fly up to the nearest window-pane (Fig. 35). Either within
doors or in the streams, nymphs can be kept in cages till they
emerge as winged maj^flies. These life history cages are
elsewhere described.

Identification. — Mayflies are divided into three subfamilies
which may be described, according to the nymphal habits of
their members, as the EphemerincB or burrowers (PL XIII),
BcEtina: or clamberers and runners (PI. XIV), and Hepta-
genince or flattened sprawlers (PI. XV).

Burrowers or Ephemerinas, Hexagenia. — Hexagenias bur-

1 JL

Fig. 154. — Heads of two burrowing mayflies dis-
tinguishable by the shape of the rostrum (a): i,
Hexagenia; 2, Ephemera. The nvmphs are shown
in PL' XIII.

204

AQUATIC INSECTS

row in the muddy shallows of lakes and rivers, sometimes in
the banks of upland bog-streams. They can be distinguished
by the rounded, shelflike piece on the front of the head
(Fig. 154). They are the largest of the mayflies, fullgrown
n^^mphs being from one and one-half to two inches long
(PL XIII). They eat the rich diatom ooze through which
they plough their way. Sloping banks are sometimes mined
by them, and the openings of the burrows with mayfly tails
hanging from them can often be seen along stream margins
(PI. XIII). If such nymphs are pulled out and thrown down
onto the mud they will burrow in again with the speed of
ground-moles.

Pig. 155. — Adult male of Hexagenia hilineata,
in its favorite position; one of the large mayflies
which swarm over lakes.

These are the mayflies which fly in such great numbers be-
neath lights and on lake shores (Fig. 155). There are many
stories and records of their abundance. According to Dr.
F. H. Krecker's observations made at Cedar Point, Lake
Erie, "when a brood is at its height it is a very common
occurrence to find piles of the insects three or four feet square
and six to eight inches deep under electric lights. At a
neighboring amusement resort several carts were required
each morning to haul away the dead insects."

205

PL XIII. — Fullgrown burrowing mayfly nymphs and
burrows: i, Ephemera; 2, Hexagenia; 3, tracks and burrow
openings of Hexagenia.

Photo. by A. H. Morgan

PLATE Xm

AQUATIC INSECTS

Season: Emerging through late spring and midsummer.

Distribution: Widely distributed throughout North America.

Ephemera. — The rostrum of the nymph, the shelflike piece
on the front of its head, is divided by a deep round notch
into two spines (Fig. 154). The Ephemeras are smaller than
the Hexagenias but very similar to them in appearance and
habits (PI. XIII).

Habitat. — They frequent smaller ponds, pools, and slow
streams where Hexagenias are not apt to be found. Outside
the large lake regions they are the commoner of the two
genera and even in some large lakes this is the case.

Season. — Nymphs are emerging throughout the summer
season but the maximum swarming of the adults occurs in the
July twilights. Nymphs can be found at any time of the
year; during a recent mild winter in New England they were
collected each month from October to April. They were
found in considerable numbers beneath muddy banks along
with hibernating Hemiptera and spotted newts.

^=*^

Pig. 156. — Nymph of Potomanthus, a mayfly
which sprawls on the mud.

Potomanthus. — Nymphs of Potomanthus sprawl on the mud
but they are not burro wers (Fig. 156). Their tusks (mandibles)
are short, not extending beyond the head as they do in the
burrowers, Ephemera and Hexagenia (PI. XIII). They live
in the side waters of streams, not far from the swift- water
haunts of Chirotenetes. Length, nymph, three quarters of an
inch. The conspicuous adults have broad, pure white wings,
and at first glance appear more like moths than mayflies.

Occurrence. — Adults, July-August. Northern New York,
Connecticut, Alassachusetts.

207

FIELD BOOK OF PONDS AND STREAMS

Fig. 157. — Blasturus cupidus, one of the common-
est mayflies in early spring pools,

I

Family Baetinse, Blasturus. — These are the commonest
nymphs in the ponds through Ivlarch and late April. They
are chestnut brown with double leaflike gills which are similar
except for the last pair. They walk over the trash or swim
through the still water of the spring pools in which the}' con-
stitute the major population. They do not try to hide from
the light and it is easy to see hundreds of them clambering
or swimming heavily about in the pools. Nymphs collected
in February are nearly fullgrown and adults begin to emerge
in March. N^^mphs will live for two or three weeks in a dish
of water if kept fresh or supplied with aquatic plants; they 1
will shed their nymphal skins successfully and then fly to the
window-panes to rest on the glass till they cast their subimago
skins.

Occurrence. — The nymphs (Fig. 157) appear in great num-
bers during March to April but they soon emerge and dis-
appear from the ponds, little ones appearing again in late fall
and winter. Length of fullgrown nymph half to three-quar-
ters of an inch. Eastern states to North Carolina and Indiana.

Callibaetis. — CaUihcetis nymphs have three tail filaments,
the outer ones being fringed on one side only (Fig. 158).

The pale green, brown-dappled Callihcetis is one of the
daintiest of the dwellers in newly formed pools and ponds
where vegetation is plentiful and carnivores are f«w (PL X).
Unlike most mayflies it matures in less than six weeks, and
there are several generations in a summer. The nymphs will

208

AQUATIC INSECTS

live for several days in aquaria. If those with black wing-
pads are captured they are almost sure to emerge within

Fig. 158. — Nymph of Callibcetis among water
weeds.

a few hours into subimagos whose spotted wings are margined

with delicate hairs (PL XI, i). Length, fullgrown nymph,

t

half an inch.

Occurrence. — Generally distributed through North America.

Fig. 159. — Nymph of Chirotenetes.

"White-gloved howdy," Chirotenetes. — The front legs of
Chirotenetes are fringed with long hairs. In addition to its
abdominal gills it has tufts of gills at the bases of its maxillae
and front legs (Fig. 159). This n3"mph lives in the tumbling
waters of stony creeks, among which it leaps and dashes with
amazing agility. There it braces itself, tail down and head
up, and holds its front legs outward to catch its food from the
current (Fig. 24).

209

PL XIV. — Clambering and running mayflies of Family
BcBtince: i and 2, two species of Ephemerella which clamber
over trash in streams; 3, Ameletus, an active dweller in small
ponds. Nymphs of Epliemerincc: 4, Tricorytlms and 5,
CcEnis, which live in bottom sand and ooze; 6, Siphlunis, a
swift-moving dweller in small ponds.

PLATE XIV

•'f^

AQUATIC INSECTS

It is a rich chocolate brown color with a light median stripe
extending from the mouth and running over the head onto
the thorax ; the front tarsi are white. Chirotenetes is a mayfly
that has the habit, rare among mayflies, of taking a mixed
djet of alg« and midge larvae. Fullgrown nymphs are an
inch long.

Occurrence. — May-July. Generally distributed through
North America.

Family Heptageninae, Heptagenia. — The HeptagenincE are
flattened nymphs which live in rapid streams or on wave-
beaten shores (PI. XV).

In most regions the Heptagenias are the commonest mayflies
of running water and they are by far the most generally
distributed of the flattened, clinging nymphs. Their hardi-
ness and their ability to endure changes in temperature and
differences in current is probably responsible for their pres-
ence in so many varieties of streams. They avoid the light,
staying on the under surfaces of the stones, and a brook
which looks utterly deserted may shelter hundreds of them.
They can be found all the year; in January the caddis worms,
Hydropsyche, are with them by hundreds.

When fullgrown they migrate into quiet waters to emerge.
Dr. W. A. Clemens calculated that Heptagenias take a year
to complete their life cycle, spending all but four or five days
of this time in the water. About two months after their
mating and egg-laying season he began to find the small
nymphs.

Occurrence. — Adults emerge through June and July.

Epeorus, Iron. — These nymphs have flattened bodies but
only two tail filaments (PI. XV). Nymphs of both these
genera live in the most rapid currents, swift eddies, torrents
and water-falls. The members of both groups are very
beautiful insects, exceedingly delicate, susceptible to changes
in temperature, and able to live only a very short time in still
water.

2IJ

PL XV. — Mayflies of the Family Heptagenince which cling
to the stones in running brooks: i, Heptagenia, fullgrown,
with black wingpads; 2, Heptagenia, another species. Alay-
fly nymphs of Family Heptagenincc which live in the swiftest
currents: 3, Iron, fullgrown nymph; 4, Epeorus, showing
its transparency just after molting. Note the white simple
eyes.

PLATE XV

i3

AQUATIC INSECTS

Their flattened bodies with thin, downcurved edges, their
knife-blade legs, and grappling claws are all adjustments to
life amid the constant pressure of moving water. Their
gills are platelike and together form a suction disk which
makes an efficient holdfast.

In Iron the first and last pairs of gills are incurved so that
their tips come closely together; in Epeorus there is a space
between every pair and the oval which they make is not
complete. In Epeorus the body is wider, more flaring than
in Iron,

Occurrence. — Adults emerge through May and July. Both
genera are widely distributed.

Dragonfiies and Damselflies — Odonata

Form and habits of adults. — The adults of this order are
the swift- winged dragonflies or devil's darning needles which
fly about the midsummer ponds on regular beats, round and
round, stopping on the same reeds like watchmen at their
time clocks. They are in pursuit of midges and such small
insect game which they capture on the wing. The damsel-
flies are leisurely, as they flit and loiter along the stream banks
while the dragonflies cut through the air like arrows. Both
groups of the Odonata have four wings with finely netted
veins ; when resting, dragonflies hold their wings straight out
horizontall}' from the body (Fig. 162); most damselflies fold
theirs close together vertically over their backs (Fig. 166).
Both have strong biting mouth parts and long bodies, very
slender, and often brilliantly colored in damselflies, stouter
and usually more somber in dragonflies. In all of the damsel-
flies and some of the dragonflies the female has an ovipositor
with which the eggs are placed within the leaves and stems
of water plants. IMany dragonflies skim the surface, dipping
repeatedly to drop the eggs into the water. Damselflies
sometimes go below the surface of the water to find a good
place for their eggs just as the little mayfly Bcetis goes under

213

Ja

FIELD BOOK OF PONDS AND STREAMS

water to explore the stones before she lays her eggs (p. 201).
One of these, Enallagma asperstim, observed by W. C. Woods,
stayed under water for twenty-five minutes. She wound her
wings around the abdomen, enclosing a blanket of air about
her, then walked down the stem of a plant and explored the
stream bottom for an area of two feet away.

Nymphs. — Dragonfly nymphs usually require a long time to
mature ; thus Gomphus needs more than a year. On the other
hand certain damselflies such as Enallagma and Ischnura
may produce more than one brood in a season. Both dragon-
and damselflies usually pass the winter as nymphs in the mud
bottoms or in trash caught here and there in flowing streams
and begin to emerge late in the spring, leaving their cast-
off nymphal skins clinging to stems several inches above water.
A newly emerged dragonfly is soft-bodied and weak, and for
a little while after molting it can fly only haltingly if at all.
Dragonflies and damselflies spend most of their lives in the
water as nymphs and during that time they are the dominant
insect carnivores of the ponds, preying upon any animal
smaller than themselves. Although they can lunge and dodge
with lightning quickness their gait is usually slow and they
have a "stop, look and listen " way of moving over the bottom

Fig. 160. — Dragonfly nymphs: i, with labium in
place; 2, with labium thrust forward as when
catching prey.

214

AQUATIC INSECTS

and stealing up on their prey, which they seize with the ex-
tended lower lip (Fig. i6o). Ordinarily this is folded back
under the head; in some species it covers the face like a mask.
When a nymph is capturing prey it thrusts its labium far
forward (Fig. 21), ready to clutch at anything which moves
and to jerk it back into its mouth and waiting jaws.

Damselfly nymphs are slender with three leaf-shaped gills
extending from the hind end of the body (Fig. 167). Those
of dragonfiies are stout-bodied and without external gills
(Fig. 162). They breathe by taking water into a chamber at
the rear end of the alimentary canal whose walls are elaborate-
ly infolded and bespread with a lace work of airtubes. Water
is drawn in and out of this tracheal chamber by way of the
anus which is guarded by five pointed spines. In collecting-
pans nymphs will often turn over on their backs and while
they are thus "playing dead" with their legs bent double,
they will be suddenly shot forward by the forcible expulsion
of a stream of water from the tracheal chamber. Thus the
chamber proves itself not only an efficient respirator}^ organ,
concealed and out of the way, but a locomotor organ as well
(PI. IX.)

Occurrence. — Nymphs of some species of dragonfiies or
damselfiies are almost certain to be abundant in mucky-
bottomed ponds half filled with vegetation (Fig. 21). But
some species of each group have settled into clear brooks
and slow-moving marsh streams (Fig. 22). Adult dragon-
flies and damselfiies begin to emerge in late April and con-
tinue till September, but in New England active nymphs may
be found in small ponds after the first of November.

Food. — These nymphs, especially the dragonfiies, eat every
kind of aquatic insect, beetle larvae, midges, and small mem-
bers of their own kind but they prefer mayfiies, small crusta-
ceans, and snails. Nymphs and adults as well are great enemies
of mosquitoes.

Associates. — Dragonfly nymphs and 3'oung fishes are com-

215

FIELD BOOK OF PONDS AND STREAMS

petitors for the same food, but dragonflies are themselves one
of the most important foods for adult fishes — pickerel, perch,
catfish, and small stream fishes (Fig. 21). An insight into
the dangers which greet the nymphs from their earliest youth
is given in an observation made by Dr. C. B. Wilson. "Two
leaves of Potamogeton illmoisensis, which contained a large
number of Enallagma eggs that were just hatching, were
brought into the laboratory August 11, 1917, and placed in a
small aquarium. On going over them with a hand-lens to
remove the nymphs already hatched, a large brown hydra
was found eating one of the tiny nymphs. It was attached
to the under surface of the leaf, nearly in the center of a large \
cluster of Enallagma eggs, and could reach many of the
nymphs with its tentacles as they emerged."

Aquarium study. — The nymphs of most pond dragonflies are ,
very hardy and will live in an aquarium all winter. But they 1
are thorough carnivores and must be supplied with small
water insects or with worms like Enchytrceida. J

Dragonflies, Suborder Anisoptera, Family Libellulidae,
adults called skimmers. — Xymphs of this family have a mask-
like labium which covers the whole front of the face up to the
antennae (Fig. 161).

Fig. 161. — XymphofL/&f//«/G; face view showing
the labium covering the face. (From Kellogg.)

Tenspots, Libellula. — Xymphs of Lihellula distinguish-
able by their squarish heads and flaring labia are common in
vegetation-filled ponds and ditches. (PI. X.) When fullgrown
they are nearly two inches long.

216

AQUATIC INSECTS

Occurrence. — In New England the adults, called "ten-
spots," emerge from the last of May to the middle of
September (PI. X).

Fig, 162. — Nymph and adult of the whitetail,
Plathemis lydia.

Whitetails, Plathemis. — The habits of these nymphs (Fig.
162) are essentially the same as those of Lihellula. Fullgrown
nymphs are about I inch long.

Occurrence. — Adults emerge from mid-May to late Sep-
tember.

Sympetrum. — These are the small, brilliant red dragonflies
which fly about near ponds, alighting on low vegetation or
sunning themselves in roadways (Fig. 163). Their striking
colors make them well known in autumn when they are active

217

FIELD BOOK OF PONDS AND STREAMS

Fig. 163. — Nymph of Sympetruni rubicundulum,
red dragonflies of autumn.

through the sunny days of September and even late November.
Dr. PhiHp Calvert studied the autumn disappearance of
species of Sympetrum and he writes, "Observations made over
20 years give the latest dates for the appearance of this species
on the wing as ranging from October 17th to November 23rd."

Dragonflies, Subfamily Gomphinae. — Gomphus (Fig. 164, 2)
is a common representative of these stream-inhabiting bur-
rowers. They have wedge shaped heads and stout 4-jointed
antennse. They sprawl or lie almost buried in the soft bot-
toms of slow streams and when they finally leave the water
they usually crawl out on the fiat shore to shed their skins.
Length of nymph, one inch.

Dragonflies, Subfamily .^schininae. — In this family the
nymphs are smooth and slender, often green or marked with
distinct color patterns (Fig. 164, i). They have long thin
legs and are active climbers among the vegetation of quiet
waters.

The adults are among the largest dragonflies, those which

218

N

AQUATIC INSECTS

fly far from their native ponds and are often seen on road-
ways and about villages. They are great hunters for mos-
quitoes and swarming midges and mayflies.

Fig. 164. — I, Young and mature n^^mphs of ^nax
Junius, one of the commonest dragonflies; 2,
nymph of Gomphus.

Anax. — The green darners {Anax Junius) ale probably the
commonest dragonflies in all parts of the country (Fig. 164).
The nymphs live in small ponds among water plants. Well
grown ones are grass green with a broken brown stripe through
the middle of the back but half grown ones are marked with
cross bands of black and white. Fullgrown nymphs are
plentiful all through October. They expel water from their
respiratory chambers with such force that when they are in a
shallow pan of water their spitting and squirting can be heard
several feet away (PI. IX). Length of nymph, i to 2 inches.

219

FIELD BOOK OF PONDS AND STREAMS

Mating adults fly about together, seldom alighting except
to deposit the eggs just below the water in the stems of picker-
el weed or other shore plants. Even while the female lays
her eggs the pair often stay together.

Occurrence. — Adults emerge from May i to October 20.

Damselflies, Suborder Zygoptera, — Damselfly nymphs are
slender nymphs whose tapering bodies bear three leaf-like
gills at the posterior end. Some of them are dark colored,
often stream-inhabiting nymphs; others are delicate, pale
green and usually live among the vegetation of quiet water.

The brilliantly colored adults fly loiteringly along water
sides.

Fig. 165. — I, Nym.ph and adult male of black-
wing, Agrio72 {Caloptcryx) maculatum; 2, wing of
female.

Blackwings, Agrion (Calopteryx). — These are the "black
wings," the familiar damselflies with brilliant green or blue
bodies and black wings (Fig. 165). They flutter along over
the border shrubbery of shaded streams with all the uncer-
tainty of butterflies. The commonest species is Agrion
(Calopteryx) maculatum. The adult male is beautiful metallic
green or blue with uniformly black or rusty black wings; the

220

AQUATIC INSECTS

female is similar but each front wing has a white spot near
the tip (Fig. 165). The female, unattended by the male,
deposits her eggs in plant stems just below the surface of the
water.

Occurrence. — Nymphs of various sizes may be found in
shallows the year round. Length of fullgrown nymph, about
I inch. The adults are on the w4ng from the middle of April
to the last of August.

Fig. 166. — Nymph and adult of damselfiy, Het-
CBrina americana.

221

FIELD BOOK OF PONDS AND STREAMS

Fig. 167. — Nymph and adult of Lestes jnceqiialis.

Hetaerina americana. — The adults (Fig. 166) have narrow
transparent wings, ver}^ different from the dark spoon- shaped
ones of the preceding genus, Agrio7i (Calopteryx) (Fig. 165),
and the males can be distinguished from other damselfiies by

Fig. 168. — Nymph and adult of Argia violacea.

222

AQUATIC INSECTS

the carmine colored flush on the bases of their wings. They
fly late in the summer (in Illinois they have been reported as
late as October 22) when they are often seen gathered in little
companies on streamside shrubs. The nymphs live in mov-
ing water — in rapids, sometimes in the lapping waters of
lake shores. They are brown or green, without any color
pattern (Fig. 166). Fullgrown nymphs are one and a quarter
inches long.

Lestes. — Nymphs of Lestes all live in ponds and small lakes
where they climb about among the plants of the shallow water.
They are very long bodied and slender with green and brown
bandings which camouflage them extremely well among their
surrounding stems and leaves (Fig. 167). Length of nymph,
three quarters of an inch.

Fig. 169. — Adult and nymph, Enallagma exsulans.

223

FIELD BOOK OF PONDS AND STREAMS

Argia violacea. — This is the commonest species of this genus
in the eastern states (Fig. i68). The nymphs live in almost
everv^ kind of aquatic situation but prefer slow streams and
coves. The species is named from the violet colored abdomen
of the adult male. The female commonly lays her eggs on
mats of algse which float in the shallow water. While she
is ovipositing the male continues to clasp her body, holding
his wings folded and his own body poised stiffly, sticking
straight up into the air. Length of nymph, about one half inch.

Enallagma. — This is a large genus of damselfiies whose
nymphs live in the tangled vegetation of small weedy ponds,
or slow-flowing streams, where they are among the most
numerous of predatory insects. Nymphs of the different
species are ver}" much alike (Fig. 169). All are slender
with the head nearly one-third wider than the rest of the body
and the gills variable in size and color pattern but not so
pointed as those of Ischnura. The labium is slender with a
prominent median lobe. Length of nymph, one half inch.

Fig. 170. — Nymph and adult of Ischnura verticalis,

224

AQUATIC INSECTS

Fork-tails, Ischnura verticalis.— This is one of the com-
monest damselflies in the United States. The nymphs resemble
those of Enallagma but their gills have longer, more tapering
points (Fig. 170). They occur almost anywhere in weed-
grown water. The adults are among the earliest damselflies to
emerge in the spring and the last to be seen in autumn. The
males are green and black ; segments 8 and 9 of the abdomen
are blue with a black stripe on each side. They seldom fly
out over the open water but flit about swamps and borders
wherever there is vegetation. Length of nymph, one half inch.

"Water-bugs — Hemiptera

Form and habits. — All water-bugs have jointed sucking
beaks of needle-like sharpness. Some of them dive or swim
in the water, coming to the surface for air (PL X); others
prowl over submerged vegetation, a few live on the surface
film. These are but a few species of the great order Hemip-
tera most of whose members belong to the forests and fields.
Although these water-bugs live on the water or close to it
throughout their days, in almost all cases, including all of the
American species, they breathe air, for they have only partially
committed themselves to aquatic life. They never have
tracheal gills. The young nymphs look and act very much
like the adults but they have shorter wrings and there is no
great change in their shape after the last nymphal molt as
there is in mayflies and dragonflies (Fig. 183). -^ While water-
bugs are comparatively few in numbers of species there are
apt to be large numbers of individuals. It is no unusual
thing to be able to catch fifty or more water boatmen with
one sweep of the net, or to see a hundred water striders in a
small streamside pool.

Water-bugs live in protected waters, thickly grown with

plants and littered with dead vegetation, or in gently flowing

•streams which have still pools and coves along their course

(PI. II). There they forage in the shallow waters where

225

FIELD BOOK OF PONDS AND STREAMS

insects and snails and the young of many water animals are
abundant (Fig. 22). The}^ are active from very early spring,
beginning to appear in the water as soon as the ice leaves the
shore; some lay their eggs by the middle of April. Their
activity goes on till late fall or early winter, depending
upon the season. With a few exceptions they hibernate as
adults. They gather for the winter in matted branches of
Chara, and skulk in the trash beneath banks. They are long-
lived, often surviving for a year or more.

Food. — ]Many water-bugs attack any animals which they
can manage, large or small. Their larger prey includes young
fish, snails, and dragonflies, but they also devour great num-
bers of small crustaceans, mosquito larvse, midge lan^as, and
insects which fall into the water from overhanging foliage.
But the water boatmen are mainly herbivorous, gathering
their food from the bottom ooze which consists largely of
algae and decaying plants. They not only maintain their
own numbers but they furnish part of the food for their
cannibalistic relatives.

Associates. — Water-bugs occupy the surface of the shallows
with whirligig beetles, springtails, and pond-snails. Water-
bugs and crayfishes are sometimes associated through a
peculiar habit of the water boatman, Ramphocorixa acuminata,
which lays its eggs upon crayfishes. The performance has
been fully described in a paper by J. F. Abbot with photo-
graphs of crayfishes laden with eggs of the water-bugs. Many
crayfishes have since been studied in eastern Kansas by
Hungerford who believes that the eggs are placed on the
regions of the crayfish (Cambarus imniunis) where they have
the best chances of aeration by currents of water from the gills.
The female of another water-bug, Belostoma, places her eggs
on the back of the male of her own species (Fig. 175), but the
crayfish carries the boatman's eggs just as safely and takes
the burden entirely off the family.

Aquarium study. — Water-bugs can be kept in aquaria for

226

AQUATIC INSECTS

long periods. The aquaria will need screen-covers, for they
can fly out of their dishes just as they can from ponds. Only
a few should be kept in a dish, for they need space, and a few
water plants to make them feel at home. They will eat small
water animals of almost any kind; the water boatmen need
only some good bottom ooze full of plant tissues. Many
water-bugs will lay their eggs and their young will hatch in
captivity.

Identification.— Excellent accounts of all the families of
aquatic Hemiptera have been given by H. B. Hungerford in
his report "The Biology and Ecology of Aquatic and Semi-
aquatic Hemiptera."

Key to families of aquatic Hemiptera here included, after
Hungerford.

1. Antennae shorter than head. 2
Antennas as long as or longer than head, exposed. 6

2. Hind tarsi with indistinct setiform claws (save in Plea

which is less than o.i inch long). 3

Hind tarsi with distinct claws. 4

3. Head overlapping thorax dorsally. Front tarsi i -seg-

mented, palaeform. Water boatmen, CorixidcB, p. 239
Head inserted in thorax. Front tarsi normal.

Backs wimmers, NotonectidcB, p. 237

4. Membrane of hemelytra (front wings) reticulately

veined. " e

Membrane of hemelytra without veins.

Creeping water-bugs, Naucoridce, p. 238

5. Apical appendages of the abdomen long and slender;
tarsi I -segmented. Water scorpions, NepidcE, p. 235

Apical appendages of the abdomen short and flat, retrac-
tile. Giant water-bugs, Belostotnatidcs, p. 232

6. Head as long as entire thorax; both elongate.

Water-measurers, Hydrometridd, p. 228

Head shorter than thorax including scutellum. 7

227

FIELD BOOK OF PONDS AND STREAMS

7. Claws of at least front tarsi distinctly ante-apical, with

terminal tarsal segment more or less cleft. 8

Claws all apical, last tarsal segment entire. 9

8. Hind femur extending beyond apex of abdomen; in-

termediate and hind pairs of legs approximated, very
distant from front pair. Beak 4-segmented.

Water striders, Gerridce, p. 230
Hind femur not extending much beyond apex of abdo-
men; intermediate pair of legs about equidistant from
front and hind pairs (except in Rhagovelia) ; beak 3-
segmented.

Broad-shouldered water striders, VeliidcB, p, 229

9. Antennee 4-segmented. Membrane of wing without

cells. Mesoveliids, MesoveliidcB (not included)

Water-measurers, Family Hydrometridae. — These bugs are
concrete examples of slendemess and deliberation. They
have long thin bodies, spindly legs, and long, elbowed-
antennas and their heads are as long as the whole thorax,
which is by no means short (Fig. 171). They walk over
dead reeds at the margin of ponds, or on duckweed and lily
leaves, and even on the surface film, always seeming to mea-
sure each step as they go. Sometimes they are found on
sphagnum moss on the edges of bog ponds, one of the generic
names in the group being Limnobates, which means "marsh-
treader."

Water-measurer, Hydrometra martini. — These water-
measurers (Fig. 171) are the most widely distributed of the

Fig. 171. — Water-measurer, Hydrometra martini,

228

AQUATIC INSECTS

family in our fauna, the other species being found in the
south. They stay about shallow pools, shut in by cat-tails
and overgrown with algal mats and duckweed where they
can be sure of a quiet place to prowl for their food (PI. II).
In order to find out what these measurers do it is necessary
to settle oneself comfortably in or near the pond since some
time elapses between their doings. Hungerford used to
keep watch on the pools, while seated on a three-legged stool
well out in the water. He saw Hydrometra spearing its food
in the water, capturing mosquito larvse and pupee, water
boatmen, and small crustaceans.

Water-measurers lay their eggs from April through mid-
summer upon stems projecting just out of the water; they are
brown and spindle-shaped, with beautifully sculptured shells,
each one being fastened separately to the leaf. Hungerford
watched water-measurers laying their eggs on cat-tail sprouts
in April. Those which he kept in his aquaria placed their
eggs on the sides of the glass just above the water. line.
Length of adult, about half an inch.

Broad-shouldered water stridors, Family Veliidae. — These
stout bodied animals are similar to the common striders,
GerridcE, in general appearance and habits. Like them they
are predator}^ and gregarious. The larger species belong to
the genus Rhagovelia which inhabits rapidly moving water.

Fig. 172. — Broad-shouldered water strider, Rhag-
ovelia obesa, showing split in tarsus of middle leg.

229

FIELD BOOK OF PONDS AND STREAMS

In one of the largest of these water striders, Rliagovelia obesa,
the terminal tarsus of the middle leg has a split in it from
which a tuft of hairs projects into the water (Fig. 172), These
can be spread out like a fan and used as an oar-blade in
travelling up the current of a stream. Length of adult,
one eighth of an inch.

Water striders, Family Gerridae. — Water striders or water
skaters live on the surface of quiet or gently JElowing water,
skimming rapidly over the surface on their spider-like legs,
drifting with the current or jerking themselves upstream
(Fig. 22). The dimples which their feet make in the
surface film cast shadows on the brook bed that are almost
as often noticed as the water striders themselves. Water
striders collect in schools along the quiet, shady, side waters
of streams from whence they scatter to shelter when alarmed
but quickly congregate again.

Their bodies have pilose surfaces, like velvet, which hold a
silvery film of air covering their undersides and completely en-
veloping them in their occasional plunges down into the water.
Their legs are slender, often long and spindling; the middle
and hind ones are close together, both pairs set far apart from
the front legs ; the long fem.ora of the hind legs extend behind
the tip of the body (Fig. 173). Very young nymphs are like
frisky little spiders, but they soon begin to look like the
adults except that they have short wings or none at all.
In several species adults, too, may be wingless or short-
winged.

Water striders are predacious on backs wimmers, on emerg-
ing midges which come up from the water below them, and
on leaf-hoppers which fall down from banks and overhang-
ing shrubbery above them. The adults pass the winter
beneath protecting mud-banks, often clustered among snarls
of CJiara and Elodea stems.

Like some other water-bugs they support many young
water-mites. Scarlet patches of the latter can be seen almost

230

AQUATIC INSECTS

as far as the striders themselves. Water-mites lay their
eggs on aquatic plants and their six-legged larvae hatch out,
soon fastening themselves to water-insects by means of their
hooked mouth parts. Their heads work deeper and deeper
into an insect's body, their legs curl up and finally only the
scarlet bag-like body shows on the outside (p. 176). Within
this bag the six-legged larva transforms and finally emerges
as a free-swimming eight -legged mite.

Fig. 173, — Large water strider, Gerris remigis,

adult.

Large water strider, Gerris remigis. — Unlike the next species
these water striders have dark under surfaces, and the adults
(Fig. 173) are usually wingless. They seem to prefer clear
running streams where they gather beside the tree trunks,
and in quiet places near bends in the shore. They cannot
migrate except by jumping and many of them are caught in
isolated pools and die there when the water dries up in sum-
mer. Both adults and young are parasitized by water-mites.
Adults, one half inch long.

Occurrence. — Common from Labrador to Mexico.

Gerris conformis. — The adults of Gerris conformis are al-
ways winged and slender and the underside of their bodies

-31

FIELD BOOK OF PONDS AND STREAMS

is yellowish. They frequent both lakes and streams and
range south through all of the Atlantic states.

Fig. 1 74. — Small water stridor, Cents margmatus.

Gerris marginatus. — This small water strider (Fig. 174) is
an abundant inhabitant of lakes and streams all over the
United States. Adults, one half inch long.

Giant water-bugs, Family Belostomatidae. — The members of
this family are wide, flat-bodied insects which have front legs
fitted for clutching and the others flattened and oar-like.
They have a pair of short, strap-shaped breathing organs at
the end of the abdomen.

Fig. 175. — Male water-bug, Bclostoma flumineum,
carr}dng eggs fastened upon him by the female.

Water-bug, Belostoma flumineum. — This is one of the
smaller members of the family which has long been incorrectly

232

AQUATIC INSECTS

known as Zaitha fluminea. It clings to stems and sticks in
still waters which hold a congested population of water plants
and insects — mayflies, damselflies, and the like. The eggs,
a hundred more or less, are carried on the back of the male
(Fig. 175) until they hatch, usually for ten days or more. .
Torre-Bueno has thus described the transfer of the parental
burden. "The female places herself on top of the male, her
thorax extending outward and her legs hooked under him;
now starting somewhere near the middle and sidling along
every little while, she works her way around him as she
fastens her eggs on his back by means of the water-proof glue
secreted for that purpose. The male all the while hangs
from the surface, back up, with his legs curled up under him,
bravely bearing up under his burden."

Occurrence. — Egg-laden males can be found commonly from
May into early September. In the marsh waters at Ithaca,
N. Y., they are very plentiful in August. Adults, one inch
long.

Fig. 176. — Electric-light bug, Lethocenis ameri-
canus, and front leg showing groove on the femur
into which the tibia can be folded.

233

FIELD BOOK OF PONDS AND STREAMS

These water-bugs are predacious upon smaller insects.
Hungerford fed the nymphs with mosquito wrigglers. They
winter as adults in the bottom trash and mud.

Electric-light bug, Lethocerus americanus. — In these giant
water-bugs the femur of the front leg has a groove into which
the tibia can be folded (Fig. 176). They are fiercely preda-
cious, devouring dragonflies, and young fish whenever they
are available, and Britton records the capture by Lethocerus
of a young pickerel which was three and five-eighths inches
long.

The brownish, oval eggs, about one-fifth of an inch long,
have been found on reeds above the surface of the water.
These bugs do not hesitate to leave the water, flying some-
times for a considerable distance, thus migrating from pond
to pond. They have been captured around electric lights
and so earned their popular name. Adults, one and one
half inches long.

Fig. 177.— Front leg of giant electric-light bug,
Benacus griseus, which has no groove in the femur.

Giant water-bug, Benacus griseus.— This electric-light bug
(Fig. 177) is slightly larger and very similar to the preceding
Lethocerus americanus (Fig. 176) except that the femur of its
front leg does not have any groove for the tibia. It can in-
flict a very painful wound with its beak.

The large streaked eggs are attached to plants above the
water line and the egg-clusters are two or three inches long.
Dr. J. G. Xeedham has written a description of the hatching
illustrated with a photograph that shows a young Benacus
pushing back the loosened caps at the free ends of the eggs.

234

AQUATIC INSECTS

The line along which the cap will open is marked on the egg
shell by a white crescent-shaped streak.

These bugs thrive in dishes of water if they are kept sup-
plied with food, such as insects and pond snails, and are
enclosed by a screen top. The eggs are so large that the young
Benacus and its hatching can be clearly seen with the naked
eye. The plant stalk bearing the cluster of eggs containing
embryos should be set up in a natural position in an aquarium,
when the whole process can be watched.

Water scorpions, Family Nepidae. — The water scorpions
have two long tail filaments which form a breathing tube, and
thev can rest on the bottom or some submerged support with
the tube thrust up through the surface film for air. No other
water-bugs have such a contrivance.

Fig. 178. — Water scorpion, Nepa apiculata,
showing its clutching fro^t legs and the tail-pieces
held together to make a/ breathing tube.

Water scorpion, Nepa apiculata. — This dead-looking bug
lurks among muddy leaves along the pond margin. Its
apparent inactivity is a watchful waiting for mayfly nymphs,
snails or crustaceans which it can clutch with its front legs
(Fig. 178) and then suck till only their husks are left. Water
scorpions do not lose their appetites easily and their fierce
sallies upon their neighbors can often be v/itnessed even in the
collecting pan.

235

FIELD BOOK OF PONDS AND STREAMS

The eggs are inserted into the decayed tissues of plants,
but their little crowns of shell filaments are left waving from
the surface and at hatching this end of the egg opens like the
cap in Benacus eggs.

Length of adult, about one half inch.

Fig. 179 — Water scorpion, Ranatra fusca, show-
ing the caudal tube which it thrusts up to the surface
for air.

Water scorpion, Ranatra fusca. — Ranatra (Fig. 179) looks
like a brown, water-logged stick which has taken to walking
and when it is lying still it is hardly distinguishable from the
twigs all about it. These water scorpions hang head down-
ward on the rushes and sedges with their air tubes thrust up
to the surface. They are common, too, among any dead
leaves and shore trash. When they are lifted out of the water
they sometimes squeak faintly, making this noise by rubbing
a roughened patch on the outside of each front leg against
the edge of the prothorax. Water scorpions are rapacious^
wantonly clutching and sucking the life blood of pond-dwelling
mayflies and tender j^oung damselflies.

According to Enock, the eggs of Ranatra are laid on half

236

AQUATIC INSECTS

decayed stems of water-plantain, Alisma, and Hungerford
has published photographs which show them beautifully
defined upon cat-tail leaves. Each egg has a round cap at the
top from which filaments extend out upon the surface of the
leaf. Length of adult, one to one and a quarter inches.

Backswimmers, Family Notonectidae. — The members of
this family are unique in their ability to swim on their backs,
which are shaped like the bottom of a boat (PI. X). Their
long hind legs are used' like oars.

Fig. i8o. — Backswimmer, Notonecta undulata,
with hind tip of its body thrust through water sur-
face for air.

Backswimmer, Notonecta imdulata. — There are several
species of backswimmers all of which hang head-downward
from the surface with their long hind legs extended like oars
and the ends of their bodies thrust up to the air (Fig. i8o).
When disturbed they dive to the bottom, carrying a silver
film of air on the ventral side of the body, and remain sub-
merged, anchored by their front feet to a plant stem. They
are extremely active, with strong grasping fore-legs and a
beak with which they can inflict a burning sting, the effect
of which may last for some time in persons susceptible to
poisons. Although they are themselves predacious, their
young are preyed upon by nearly every other carnivorous in-
sect including adults of their own kind. They produce many
young; Hungerford found 252 mature eggs in Notonecta
irrorata. In that species egg-laying goes on from Alarch to
June and the adults live at least a year. Notonecta undtdata
(Fig. 180) is the commonest backswimmer, and is generally

237

FIELD BOOK OF PONDS AND STREAMS

distributed all over the United States. Length of adult, one
half inch.

Fig. i8i. — A slender backswimmer, Btienoa mar-
garitacea, with front and middle legs folded.

Buenoa margaritacea. — This genus (Fig. i8i) includes a few
slender backswimmers which have the habit of swimming and
hanging in mid- water. The wings are moonlight white ; there
is a flush of pink on the back of the thorax and the underside
of the abdomen is deep red. Hungerford could not discover
their eggs in ponds but from the shape of the ovipositor de-
cided that they were laid in plants. When smart-weed stems
were put in the aquarium with them the females promptly
riddled them with eggs.

They live upon small crustaceans which they hold while they
feed upon them in a sort of cage made by the bristles of their
first four legs. Length of adult, one quarter of an inch.

Creeping water-bugs, Family Naucoridae. — These are broad,
thick-set bugs of moderate size in which the hind legs are not
flattened for svv-imming as they are in the backswimmers and
water boatmen but the front femora are greatly thickened
(Fig. 182). They creep about on the stems in quiet water
which is densely grown with vegetation. They bite or "sting"
on the slightest provocation.

1

Fig. 182. — Creeping water-bugs: i, Pelocorisfemo-
ratns; 2, the pigmy water-bug, Plea striola.

238

\

AQUATIC INSECTS

Plea. — The pigmy water-bugs of this genus (Fig. 182, 2) are
not more than a fifth of an inch long. They live in tangles
of water plants feeding upon minute crustaceans.

Water boatmen, Family Corixidae. — Water boatmen (Fig.
183) are dark grayish or thickly mottled gray and black.
Their hind legs are flattened for swimming and extend out
like those of the backswimmers, but water boatmen always
swim with their backs up; their middle legs are long and end
in very slender claws. The boatmen dive down with their
bodies wrapped in a glistening blanket of air and being so
much lighter than the water they have to anchor in order to
stay below. They do this by almost imperceptibly catching
one claw of the middle leg into some plant stem (Fig. 183)
and hang there atilt in the water for long intervals. Indeed
they spend a good part of their time on the bottom for they
feed upon the soft vegetable ooze which gathers there, diatoms,
desmids, filamentous algae, and the like (PI. IV). Hunger-
ford discovered that water boatmen are vegetarians, thus
disproving the old statement that all aquatic Hemiptera are
predacious. He found Spirogyra filaments v/ith their cells
sucked so empty by boatmen that only their walls remained.
They are orobably omnivorous since Hale in Australia ob-
served them feeding on mosquito larvae.

It is difficult to distinguish one species of water boatmen
from another, and even the genera are hard to differentiate.
One of the commonest species is here figured; many are similar
to it.

Water boatman, Arctocorixa (Corixa) altemata. — Like
others of the family this water boatman is active all winter.
Large numbers of corixids have been taken every month of
the year from a gently flowing stream near South Hadley,
Massachusetts. In midwinter they hide under the banks
in tangled masses of Chara where they are far from inactive
(Fig. 183). In Ithaca, N. Y., on May 9 Hungerford found
red water-mites (p. 175) on about eighty five percent of

239

FIELD BOOK OF PONDS AND STREAMS

Fig. 183. — Water boatman, Arctocorixa (Corixa)
alternata: i, nymph; 2, adult grasping a submerged
Chara stem, a characteristic pose.

this species and by May 15 the total population was infested
with them. Length of adult, one quarter of an inch.

Alderflies, Dobsons, Fish-flies, Spongilla-flies — Xeuroptera

Members of only two families of the Nenroptera in our
fauna have aquatic larvse, the SialidcE, which contains the
alderflies, dobsons, and fish-flies, and the Sisyridce or Spon-
gilla-flies.

Form and habits. — The adults have four wings and are
named Neiiroptera because of the many fine veins which run
through the wings. There is a complete change of form from
larva to adult, and the fullgrown larva always climbs out of
the stream to pupate.

Occurrence. — The larvae of the Sialidce live in swift water,
where they hide under stones and are frequently found in
riffly shallows throughout the winter, but the Spongilla-fiies

240

AQUATIC INSECTS

have followed the sponges and are often found on them in
quiet water (Fig. 187).

Food. — They are probably carnivorous but their food habits
are not thoroughly known.

Aquarium study. — Neuropterans are secretive insects not
easy to obser\'e in their own homes, and the larvae are diffi-
cult to keep in aquaria unless running water can be arranged
in them. Something has been learned about them by field
observation and by keeping them in cages.

Identification. — Key to genera of aquatic Neiiroptera larvae,
from "Fresh Water Biology," Needham and Needham
(Bibliography, p. 407).

1 . Large forms with biting mouth parts.

Alderflies, dobsons. Sialidce, p. 241. 2

Small forms with piercing mouth parts. Spongilla-

flies, etc. Hemerohiidce (Sisyridce) , p. 245. 4

2. Body ending in a long median tail. Stalls, p. 241
Body ending in a pair of stout hook-bearing prolegs. 3

3. Lateral abdominal filaments with a tuft of tracheal gills.

Corydalis, p. 243
Lateral abdominal filaments with no tracheal gills be-
neath. Chaidiodes, p. 244

4. Bristles on back of thorax sessile. Sisyra, p. 246
Bristles on back deviated on tubercles.

Cllmacla, p. 245

Family SialidcB

Alderflies, dobsons, fish-flies

Smoky alder fly, Sialis infumata. — Alderflies (Fig. 184)
were so named by the English fishermen because they settle
on the alder bushes which overhang the streamside; in Wales
they are called "hump-backs." They are he^vy, awkward
fliers which are easily captured; when approached they will
often run rather than take to their wings.

241

FIELD BOOK OF PONDS AND STREAMS

Fig. 184. — Smoky alderfly, Sialis infiimata: I,
larva; 2, adult.

They are active in the day time, especially in bright sun-
shine, usually laying their eggs at midday. These are deposit-
ed in fiat masses of 200-500 and there are usually several
masses within an area of a few inches on some leaf, board
or stone which overhangs rapid water, so that the lar\'ae fall
into the current as soon as they hatch. The eggs are C3'lin-
drical, dark brown, and at the end of each there is a little
club-shaped projection visible with a hand-lens. The eggs
are placed slightly slantwise to the surface with the little
projection pointing upward.

The larvas (Fig. 184) live in the sandy or muddy bottoms
of the streams or ponds, often buried several inches below the
bottom surface where they are hidden from their relatives
and greatest enemies, the Corydalis larvae. They are brown,
and heavy skinned; when fullgrown they are about an inch
long. Each of the first seven segments of the abdomen bears
a pair of five-jointed, tracheal gills which are fringed with

242

AQUATIC INSECTS

hairs, and at the end of the abdomen there is a similar but
unjointed gill.

The larvas are predacious upon caddis worms and upon one
another. They do not come out of their hiding places until
they are ready to pupate, when they clamber out on land
and seek another hiding place or burrow in the moist earth.

Dobson-fly, Corydalis comuta. — The larvae of Corydalis
cornuta (Fig. 185, i), commonly known as crawlers, hell-
grammites, and bass bait, live under stones in the swiftest part
of rapid streams (PI. I). They are fiercely predacious insects,
and will seize upon mayflies and stoneflies as soon as they are
put in the same collecting dish with them.

When fullgrown they are 2 or 3 inches long with dark brown,
rough looking skin, and large jaws which they extend lustily
at the slightest irritation (Fig. 185). Their bodies are

Fig. 185. — Dobson-fly, Corydalis cornuta: i, larva;
2, head of adult male; 3, adult female.

243

FIELD BOOK OF PONDS AND STREAMS

flattened and sprawling and there is a tuft of white hairlike
gills at the base of each of the lateral appendages on the first
seven abdominal segments. Corydalis larvae avoid the light
and are seldom seen unless stones are suddenly pulled from
the rapids; then they cling to the surface or hitch themselves
rapidly backward by their posterior grappling hooks. In May
and June when they are about three years old they crawl out
on shore and under a stone or log to pupate. At first the
pupa is pale-colored and soft but it gradually darkens during
the pupal life which lasts about ten days.

The adults have cinnamon brown bodies, and gray-white
spotted wings which measure four or five inches from tip to
tip when fully expanded. The female (Fig. 185, 3) has short,
stubby mandibles but those of the male (Fig. 185, 2) are
tusklike, more than three times the length of the head, and
used to hold the female during mating. As adults the dobson-
fiies are short-lived, and although they have strong jaws
they probably eat nothing. They are often attracted to
lights at night and sometimes fly high about street lamps,
usually falling to the ground after a few circles. The eggs
are laid on stones or sticks overhanging the water and there
may be two thousand or more of them in a single chalky
white mass but an inch wide.

Fish-flies, Chauliodes pectinicomis. — The larvae of Chau-
liodes (Fig. 186, i) are similar to Corydalis but do not have
gill tufts at the bases of the lateral filaments and when full-
grown they are only half as large. They are not confined to
swift streams, but are often found clinging to submerged
trash in quiet side waters. They are predacious, those kept
in aquaria being successfully fed upon live backswimmers
and house flies. The length of the larval life must be con-
siderable, for Davis kept them in running water from Septem-
ber 1899 to June 1900 yet even at that date they had not
completed their growth. Like Sialis and Corydalis they
pupate beneath stones on the stream banks.

244

^

AQUATIC INSECTS

Fig. 1 86. — Fish-fly, Chauliodes pectinicornis: i,
lar\-a; 2, adult.

The adult of the common species Chauliodes pectinicornis
(Fig. 186) is cinnamon color, shaded and streaked with yellow,
and the wings are gray-brown wnth an incomplete band and
spots of white. The masses of reddish brown eggs, each mass
containing from 1000-2000 eggs, are deposited on leaves or
branches overhanging the water. Thirt}^ or more of these
egg masses have been found clustered together within a radius
of two feet on a rock a couple of feet above the stream. The
eggs are oval and lie with the long axis parallel to the surface,
each egg bearing a little knob-like projection.

Family Sisyridce

Spongilla-fiies

Adult Spongilla- flies are small, smoky brown or variegated
fou --winged insects (Fig. 187, 2) that are little known except
to the specialist.

245

FIELD BOOK OF PONDS AND STREAMS

Fig. 187. — Spongilla-fly, Sisyra umhrata, which
lives in fresh water sponges: i, lar\^a; 2, adult.

Their pale-colored larvse (Fig. 187) live in the cavities of
a fresh water sponge and feed upon its substance (p. 109)
Their bodies are sparsely covered with bristles which catch
torn fragments of the sponge and effectually camouflage them.
Their long, slender jaws are grooved on the inner sides so
that when they are held together they form a tube. This is
thrust into the soft sponge and its tissues are sucked up
through it. Either the food thus secured contains little
waste or it is wholly absorbed in the stomach, for there is no
posterior opening to the alimentary canal and it is unlikely
that waste could pass out at the mouth as it does in Hydra.
The fullgrown larva finally leaves the sponge, climbs out of
water to some leaf or twig and spins its silken pupal cocoon.
This silk is produced by its kidne\"-like Malpighian tubules
which have taken on a silk-secreting function. It comes out
of the hind end of the body through spinnerets similar to
those of spiders.

There are two genera of Spongilla-fiies which have similar
life-histories and make such cocoons. Larvce of Climacia
weave a cocoon covered with a hexagonal meshed net while
Sisyra makes one covered with a sheet of silk. Lengt.i of
Sisyra larva, about one quarter inch.

246

AQUATIC INSECTS

Caddis flies — Trichoptera

Adult caddis flies look like moths but their bodies are more
slender and they are more delicately built. They are soft
brown, or gray, sometimes black, very rarely bright colored.
Their four wings are folded like a tent over their backs, and
their thread-like antennae, often longer than their bodies, are
extended far out in front of them. As in the butterflies and
moths their color lies mainly in the long, silky hairs and scales
which cover their wings and soft bodies. Caddis flies do not
go far from the watersides and they are seldom seen in the
daytime. Some swarm at dusk over water and under trees
but at night they gather around electric lights which are
near streams or on lake shores, and they may then be seen by
hundreds, creeping up on the lamp posts or fallen upon the
ground below them.

Fig. 1 88. — Caddis fly life-history: i, larva; 2, pupa;
3, adult; 4, leaf-case.

Caddis flies are mostly known by their larvce, the familiar
caddis worms or stick- worms which live in ever}^ brook (PI. I),
often creeping over the bottom where they can be clearly
seen from the banks. The best known are those which live
in cases made of little pebbles, or sticks or leaves which they

247

FIELD BOOK OF PONDS AND STREAMS

have cemented together with their own saliva (Fig. 198).
When a caddis worm outgrows its case it occasionally squirms
out and makes a new one, selecting the same materials and
building by the same pattern, but it generally enlarges its
case by simply building onto the front edge. It holds itself
in the case by draghooks at the hind end of the body but its
head and thorax are protruded during its continual clamber-
ing. Their gills are filamentous, in many being attached
along the sides of the abdomen, completely protected by the
case. Three tubercles (Fig. 188, i) keep the body from press-
ing against the edge of the case and give the water a free
entrance into it. It is kept circulating over the gills by un-
dulating movements of the body which the larvae will con-
tinue even after they are removed from the cases.

The pupse (Fig. 188, 2) live in cases and some larvas never
have any cases till they are nearly ready to pupate. They
are as truly aquatic as the larvae, and they have gills like them.
There are no other aquatic insects whose pupje have gills
except a few groups of flies, such as Simulium and Chironomus.
The larvae keep up a continuous foraging and eating until
they are fullgrown, when they spin silken screens across the
open ends of their cases, or fasten little pebbles over them,
and within the cases they begin their pupation or change to
the adult form. Water is let in, other things are shut out.
Such pupal cases are often fastened to a stone and all through
the early summer dozens of them belonging to little Heli-
copsyche pupas (Fig. 199, i) can be found glued fast to the
edges of the rocks. All caddis fly pupae are more or less
active and many continue their undulating motions to keep
the water flowing over their gills. By the end of the pupal
period the heavy- jawed, hungry larvae are changed into dainty
adults which do not eat at all (Fig. 188, 3). In swift water
species the pupas after leaving their cases swim to the surface,
shed their pupal skins, and instantly fly into the air; quiet
water pupae clamber out on the shore or upon projecting stones.

248

AQUATIC INSECTS

Some caddis flies, like the HydropsychidcB, lay their eggs in
beautifully regular layers upon submerged sticks, and the
hundreds of little embryos can be seen through the trans-
parent shells. The eggs of some of the Phryganida are
embedded in rings of gelatine, hung on aquatic plants.

Habitat and season. — For every kind of aquatic situation
there is a caddis fly population, net-builders (PI. XVI) in the
rapids, clamberers and floating case-bearers in the gentle
currents. Different species of caddis flies have very definite
seasons when they emerge from the water as adults, and in
many kinds these are brief periods. But some can be found
all through the summer and a few, especially the net-builders,
HydropsychidcB (PL I, 6), can be found all winter.

Microcaddis files, Family Hydroptilidae. — The larvae are all
less than one-quarter of an inch long; abdomen wider than
thorax; their cases (Fig. 189J shaped like spectacle cases and
generally carried edge upward.

Fig. 189. — Larva and case of Ithytrichia confusa,
a microcaddis worm. (After Lloyd.) -^

Ithytrichia confusa. — The case of at least one species, Ithy-
trichia confusa (Fig. 189), is fastened limpet-like to the stone.
This is an oval parchment-like one, about a quarter of an
inch long, with an opening at one end through which the larva
feeds. They are common both in quiet water and flowing
streams.

Family Rhyacophilidae. — This family is divided into two sub-
families but the larvae of both live in rapidly flowing streams.

249

FIELD BOOK OF PONDS AND STREAMS

Members of the subfamily RhyacophilincB, represented here
by Rhyacophila (Fig. 190), do not make cases until they are
full grown and ready to pupate when they wall themselves
in loosely and spin a parchment-like cocoon. In the other
subfamily, Glossosomatince, the larvae make cases of which the
turtle-shaped Glossosoma (Fig. 191) is a type.

Fig. 190. — Caddis worm, Rhyacophila.

Rhyacophila. — This larva creeps about naked on the under
surfaces of stones in riffles until it is fullgrown. It then
enters a crevice between them and walls itself into a chamber
much larger than itself, by fastening the pebbles together
with its own saliva. Here it spins a brownish, parchment -
like cocoon within which it transforms (Fig. 190). The adults
emerge from late May to the middle of July, probably all
summer. Length of fullgrown larva, one half inch.

'■^J^//// y/jjjj}lliii>

Fig. 191. — The turtle-shaped case of Glossosoma
americana: I, upper and 2, under side. (After
Lloyd.)

Glossosoma americana. — These larvse build turtle-shaped
cases of pebbles and sand grains (Fig. 191). They live singly

250

^

AQUATIC INSECTS

on the brook bottom until they are fiillgrown and ready to
pupate and then they congregate upon the sides of stones
with their cases placed edge to edge. Each larva cuts away
the old floor of its case and fastens the rim which is left to
the rock. Under this protecting canopy it spins its pupal
cocoon. Larvae, pupse, and adults are found all summer.
Length of case, little less than one half inch.

Net-spinning caddis worms, Family Hydropsychidae. — This
family is represented in almost every shallow stony brook by
hundreds of HydropsycJie larvae and their nets.

Fig. 192. — Net-spinning caddis worm, Hydro-
psyche (Macronema) ; for net see PI. XVI. Width of
cup, one half inch or less.

Hydropsyche (Macronema). — The cup-shaped nets of Hy-
dropsyche are built in crevices or on the edges of rocks in
waterfalls and riffles (PL XVI). The cup always opens
upstream and the larva lies in a loosely woven tube close at
the side, whence it can easily reach the food which the water

251

PI. XVI. — Cuplike food-collecting nets spun by caddis
worm, Hydropsyche {Macronema) : the larva lies concealed at
the side of the net, occasionally reaching in for its food: i,
inside of cups opening upstream; 2, bottom or downstream
side of the cups.

Photo, by A. H. Morgan

PLATE XVI

i

AQUATIC INSECTS

brings into the net. When fullgrown the larva makes a case
of sand grains in which it pupates. It lives only in rapid
streams and on wave-beaten shores. Length of fullgrown
larva, one half inch.

The correct name of this caddis worm is Macronema (see
Kraffka, Bibliography, p. 419), but Hydropsyche has been so
generally applied to it that it is hardly recognizable under
any other name.

Fig. 193. — Net of Polycentropus. (After Noyes.)

Silken-tube spinners, Family Philapotamidae. Polycen-
tropus.— This genus makes delicate tubular nets (Fig.
193) I inch long. There are two openings, a large one
facing upstream, at the end which is attached, and a
smaller one at the end which floats free. Usually there are
several, sometimes many, nets near together. The larva
stays within the net and feeds on the food which is caught
there.

Phryganeids, Family Phryganeidae. — These caterpillar-like
larvas of ponds and gently flowing streams are the most con-
spicuous and the best known of the caddis fly larvse. The
black and yellow head and thorax and the habit of constant-
ly "pumping" their bodies are characteristic of all of them.
They are plant feeders.

Neuronia. — Larvae of Neiironia make cases, about one inch
long, of bits of thin leaves cut almost square and arranged in

253

FIELD BOOK OF PONDS AND STREAMS

Fig. 194. — Cases of phryganeids : i, Neuronia
postica; 2, cases of larvce of Phryganea vestita.

rings (Fig, 194, i). When ready to pupate they creep into
crevices and burrow into wood or beneath bark.

Phryganea vestita. — This caddis worm Hves in ponds among
submerged plants, rarely on the bottom. Its case is made of
narrow strips of leaves arranged in a spiral and securely
glued together (Fig. 194). Young larvae do not trim off the
ends of the leaf strips, which gives their cases an unkempt,
unfinished look (Fig. 194). When preparing to pupate the
larva burrows into submerged wood leaving the end of its
case protruding. Adults emerge from the middle to the last
of June.

Family Molannidae. — Larvae of the genus Molanna (Fig.
195) are often found in great abundance on the sandy bottoms
of slow streams and ponds.

Fig. 195. — Case of Molamia made of sand grains.

Family Leptoceridae. — These caddis worms all make porta-
ble cases but of diverse shapes (Fig. 196).

Leptocerus. — Larvae of Leptoceriis drag their cornucopia-
shaped cases (Fig. 196) over the stones in riffles and in the
side waters of rapid streams.

254

AQUATIC INSECTS

Fig. 196. — Cases of leptocerids; i, Leptocerus;
2, Tricefiodes.

Triaenodes. — The larva of Tricsnodes swims rapidly about
carrying its case (Fig. 196) with it among submerged plants
in quiet bays and ponds. The case resembles that of Phi'y-
ganea (Fig. 194), but it is smaller and the leaf -fragments are
finer and fitted together with more precision. The delicate
spiral egg-masses are laid on the under surfaces of lily pads
(Fig. 18 and PI. XVII), sometimes containing about two
hundred eggs though each is but one-fifth of an inch wide.
The adults begin to emerge in the middle of June and the
eggs are found from then on through early midsummer.

Family Odontoceridae. — The larvae of only a single species
of this family have been described (Lloyd).

Fig. 197. — Case of Psilotreta.

Psilotreta. — Larvae of Psilotreta are found in the riffles of
stony brooks. During the winter they crawl over the bottom
but in early spring when they are ready to pupate they gather
on the sides of stones, fastening their cases (Fig. 197) there in
piles. In these piles the cases are always placed parallel to
one another with the head ends pointing toward the surface.
Length of case, one half inch.

255

A

FIELD BOOK OF PONDS AND STREAMS

Family Limnophilidae. — The caddis worms of this family are
most abundant in ponds and slow-moving streams. The
cases of different species are made from a great variety of
materials and sometimes the young and old larvae make very
different cases.

Fig. 198. — Case of Limnophilus combinattis.

Limnophilus combinatus. — When they are young the larvae
make cases of the log cabin type, but when they mature they
migrate away from the grassy shorelines and gather their
building materials from the bottom, using bark and seeds.
When little mollusks are available the case may be made
almost entirely of Planorbis (Fig. 251), and SphcErium (Fig.
266) shells with their occupants often still alive; such cases
are about three quarters of an inch long.

Family Sericostomatidae. — These are caterpillar-like larvae
w^hich are found in both streams and lakes.

Helicopsyche. — The little Helicopsyche cases (Fig. 199) are
good examples of objects which may be in abundance before
our eyes yet altogether undiscovered. Helicopsyche lar^^as
are rarely seen when they are creeping over the sandy bottom,
only becoming known when the fullgrown larvae cluster by
dozens upon the rocks and fasten their snail-shaped cases
down tightly to them in preparation for the pupal change.
They weave silken lids over the openings of the pupal cases;
these can be seen with a hand-lens. The adults emerge in
June and July.

Cases less than a quarter of an inch wide.

Goera. — The larvae of Goer a can be found on current-swept
rocks from late summer till the end of March. Their cases

256

AQUATIC INSECTS

Fig. 199. — Cases of i, Helicopsyche; 2, Goera; 3,
Brachycentrus.

(Fig. 199, 2) are slightly flattened and like those of several
other caddis larvae they have ballast stones glued on each side
which keep them from being carried away by the current. In
March the cases are fastened down for pupation to exposed
stones in the full current, and a pebble placed over the open-
ing. The adults emerge through April and May.

Brachycentrus. — During its early life Brachycentrus (Fig.
199, 3) lives in the side waters of brooks actively foraging
along the banks, then it moves into mid-channel and attaches
one front edge of its case to a stone. It always chooses
an exposed place and faces up-current, holding its legs
extended upstream like the mayfly Chirotenetes (Fig. 24).

During its browsing days the larva first lives upon diatoms,
and then upon algas, but when about six weeks old it adds to
this a diet of mayflies, water-mites, midge larvae, and small
crustaceans. Case of full grown larva, one half inch long.
The adults emerge late May-June.

Aquatic Moths — Lepidoptera

Water caterpillars. — Alost caterpillars are like cats; they
walk to the shore but they do not go into the water. Among

257

FIELD BOOK OF PONDS AND STREAMS

the great group of North American moths and butterflies only *
a few moths, most of them belonging to one family, the
Subfamily NymphulincE, have aquatic larvas. They are
typical caterpillars which have six true jointed legs on the
thorax, and flesh}^ prolegs on the abdomen.

They feed upon diatoms and the tissues of higher plants.
Most of them live in quiet waters overgrown with bladder- j
worts, Elodea, pickerel- weed, or the yellow and white pond-
lilies. At least one species has been found in swift streams.

About half of them breathe air, the others breathe through
thread-like gills which are arranged in rows along the sides
of the body. Those of the genus Nymphula bite o^ pieces
of leaf and make cases which they line with silk.

^f^^

Fig. 200. — i, Lily -leaf caterpillar, Nymphula ma^
culalis, and 2, its floating leaf -case; 3, the moth
(one inch long).

Lily-leaf caterpillar, Nymphula maculalis. — The cater-
pillars of Nymphula maciilalis, the lily-leaf caterpillar (Fig.
200), are common in quiet water among yellow and white
water-lilies. They live in leaf-cases (Fig. 200) which they
make by biting off two pieces of lily pad, each about an inch
long, and fastening the edges together with strands of silk,
or sometimes they bite off one section and attach it to the
underside of the same lily pad. The pieces are arranged
shiny side out and almost always appear newly cut. Some-

258

AQUATIC INSECTS

times they are separated from the lily pad, sometimes moored
to it by a strand of the torn tissue. They are filled with water
but the larvae can breathe by means of bushy branched gills
extending from the sides of the body. They feed upon the
leafy walls of their cases, first upon the inner layer and when
they are older, upon the shiny outside.

In this, as in other species, there appear to be two broods
of caterpillars; the first one makes the full-sized cases common
in June and July. These pupate within leaf-cases also usually
beneath a lily pad, and the adults which fly about over the
lily ponds have mouse-gray front wings and white hind ones
(Fig. 200). Soon another generation arises, the caterpillars
of which sink down through the water in autumn and hiber-
nate among the water-sodden leaves of the lily plant. Com-
mon and generally distributed.

Fig. 201. — I, Lily-leaf caterpillar, Nymphula
obliterans; and 2, its floating leaf-case; 3^ moth.

Lily-leaf caterpillar, Nymphula obliteralis. — In the southern
states it is a pest upon water-lilies. These caterpillars (Fig.
201) make their cases, about one half inch long, of the leaves
of water-lilies and pondweeds. They have no gills and are
entirely dependent upon the bubble of air which surrounds
them in their leaf-cases. The male moths are dull black
with obscure markings of yellow and white; the females are
browner and of larger size.

259

FIELD BOOK OF PONDS AND STREAMS

Occurrence. — Quebec and south; common southward, New
York, Rhinebeck.

Fig. 202. — I, A caterpillar of rapid waters, Elo-
pJiila fulicalis (after Lloyd); 2, pupal case (after
Lloyd); 3, the moth.

Although most aquatic caterpillars live in quiet waters,
there is at least one, Elophila fulicalis (Fig. 202, i), which is
at home in the rapid streams where mayflies and stoneflies
abound. There it lives on water-washed rocks, breathing by
means of the unbranched tracheal gills which extend in double
rows along each side of its body.

It weaves a silken canopy above itself, cementing the irreg-
ular edges to the rock except in two or three places. These
openings allow the water to circulate freely beneath the cur-
tain. Canopies made by young larA^ae are only half an inch
long but those of the fullgrown larvae measure four or five
inches long and are an inch wide. The caterpillars feed
upon the algal ooze covering the rock beneath them, the
abundant Scenedesmus and the beautiful green spheres of
Pediastrum.

Shortly before it is ready to pupate the fullgrown larva

260

AQUATIC INSECTS

cuts its canopy away, leaving only a clean scar on the rock
surface. Within the area of this scar it makes its pupal case.
This has an inner case of loose-spun silk wliich encloses the
pupa with radiating threads which suspend it from a canopy
thicker than the larval one but perforated with a circle of
six or more clean-cut holes which let in the water.

The moths (Fig. 202, 3) emerge in Jun? and July and the
vegetation near the stream sometimes swarms with them.
Their front wings are gray-brown and their hind wings white
marked with a curved blackish band. Common and general
in distribution.

Beetles — Coleoptera

When they are fuUgrown nearly all beetles have thick
wing-covers or elytra which hide the thin hind wings beneath
them. They change greatly in form from larva to pupa to
adult (Fig. 203) and the young in no way resemble the mature
beetles. As a group beetles are preeminently land insects.
Of the 150,000 or so species of Coleoptera included in approxi-
mately eighty families only a few families are made up of
water-loving beetles.

Fig. 203. — The change of form in a water-beetle;
I, larva; 2, pupa (after Wilson); 3, adult.

261

FIELD BOOK OF PONDS AND STREAMS

Adults and pupce of water-beetles breathe air and most of
their larvae do likewise. Some of the most interesting
habits and structures of these larvae are those by which they
remain in the water and still contrive to have access to air.
Only a few of them have tracheal gills which enable them to
breathe under water; the family Gyrinidce, whirligigs (p. 271),
and a few of the Hydrophilidce (p. 273), have filamentous gills
along the sides of the abdomen; DryopidcE and the Psepheni-
dcB or water pennies (PI. VIII) have fringed gills beneath the
body.

Some beetles are familiar to everybody although under
names which disguise their identity, potato "bugs," rose
"bugs," fire "flies," and maybeetles commonly called June
"bugs." •

If a diving beetle like Dytiscus be compared with any of
them its adjustments to water life will be very apparent.
An adult Dytiscus (Fig. 209, i) has a compact, rigid, slippery
body, its head forming the point of a wedge and the smooth
sides of the body the rest of it. The underside is boat-
shaped, and the hind legs bladed like oars. Between strokes
it folds its legs close against the body, and pulls its antennae
down so that there are no outriggers to resist the water. It
carries a reservoir of air lightly shut in between its wing
covers and the body; its air-tubes or tracheae open into this
reservoir making it available for breathing. Water-beetles
carry their air supply in different ways and use it for support
as well as for breathing. The underside of the body of a
whirligig beetle is covered with short hairs which catch a
film of air, buoying it up on the surface, but none of it is acces-
sible for breathing. The hydrophilids and the water striders
of the Hemiptera have similar air-floats, which appear to
lighten their body weight as swim-bladders do for fishes or
air-sacs for honey-bees.

Habitat, season. — Nearly all aquatic beetles live in quiet
water thickly grown with plants on which they hunt for their

262

AQUATIC INSECTS

prey and on which they lay their eggs. They frequent still
pools strewn with plant litter and overspread with algae;
shore waters populated with insects, and with young water
animal? of all kinds (PL X). The few larvse such as the water
pennies which live in rapid water are very unlike their rela-
tives.

Among the mayflies and dragonfiies the young are thorough-
ly aquatic while the adults are thoroughly eerial ; the nymphs
are the long-lived forms in which these insects winter over
and get through the difficult crises of their lives.

On the other hand, most water beetles, except the water
pennies, winter over as adults. Whirligig beetles hide in
the mud and come out with the first spring days, sometimes
on warm days in midwinter, and they abound in the open
waters all summer as well and into the late fall. Water
pennies, larvae of Psephenus, forage through the winter on
diatom-covered stones in swift riffles (PI. I).

Food. — Diving beetles (Dytiscidce) and whirligigs {Gyrinidce)
are predacious all their lives, the crawling water-beetles,
HaliplidcB, and water pennies, PsephenidcB, are vegetarian,
while the Hydrophilidcz are apt to be predacious as larv^
and vegetable eaters when they become adult. Larvae of
the dytiscids, gyrinids, and haliplids suck their food through
mandibles which are grooved for the passage of juices; the
others chew their food.

Associates. — Plants and animals which are the food supply
of beetles will be mentioned in the discussions of the dif-
ferent families.

They have many enemies, counting themselves among the
worst, for all of the predacious beetle larvae are cannibals from
the day they are hatched. Needham and Williamson worked
with one beetle, Hydroporus, which was so blood-thirsty that
they had to construct compartments in which each larva
could be isolated during their study of its habits. The parti-
tions projected well above the water but the larvae climbed

263

FIELD BOOK OF PONDS AND STREAMS

over them and mingled; and there was soon but one sur-
vivor. Dragonfly nymphs devour many beetle larvae; Anax
nymphs (p. 219) take a daily toll of them.

In the stomach of a painted turtle (PI. XXIII), a little
over two inches long, Baker found that the wing covers of
beetles formed five per cent of the food mass, and in another
only about an inch long, the remains of beetles composed
forty per cent. Water birds harvest the beetle crop con-
tinually and ducks consume the adults by hundreds.

Aquarium study. — Both adults and larvas thrive in aquaria
and many of their swimming and breathing habits can be
best observed there. Like other animals in captivity they
are apt to change their food habits ; those which are herbivor-
ous may become predacious. Larvas will clamber out of
aquaria and adults will fly up from them as they do not do
from the ponds. If the water is well oxygenated and they
are given enough living prey they can be kept in aquaria the
year round.

Identification. — Kej-s to families of beetles here mentioned,
from Needham and Needham (Bibliography, p. 416), slightly
modified.

The Chrysomelidae (except one genus, Donacia), a family
of terrestrial beetles later mentioned (p. 278), are not in-
cluded in these keys.

Families of Adult Water Beetles

1. Hind leg shorter than the fore leg; eyes divided (whirli-

gigs). Whirligigs, GyrinidcB, p. 271

Hind leg longer than the fore leg; eyes simple. 2

2. Base of hind legs covered by coxal plates (creeping

water-beetles) .

Crawling water-beetles, HaliplidcE, p. 265
Base of hind leg exposed. 3

3. Antennae shorter than the palpi (scavengers).

Water scavengers, HydrophilidcB, p. 273
Antennae longer than the palpi. 4

264

AQUATIC INSECTS

4. Hind cox£e broadly fused with the metasternum.

Diving-beetles, Dytiscidce, p. 266
Hind coxas free (riffle beetles).

Riffle-beetles, Psephenidce, p. 277

Families of Larvae of Water Beetles

1. Tarsal claws two. 2
Tarsal claws one. - 3

2. Four hooks at each end of abdomen. GyrinidcB, p. 271
No hooks at each end of abdomen. Dytiscidce, p. 266

3. Carnivorous, with conspicuous rapacious mandibles.

HydrophilidcB, p. 273
Herbivorous, with short blunt mandibles. 4

4. Legs absent — larva attached to plant by a bristle tube.

Donacia of Chrysomelidce, p. 278
Legs well developed. 5

5. Abdomen with numerous rows of dorsal spines.

Haliplidce, p. 265
Abdomen with 2 rows of low tubercles or none.

PsephenidcB, p. 277

Crawling water-beetles, Family Haliplidae. — These are
small beetles (Fig. 204), one-fifth of an inch or less, which
crawl through the litter in every little pond; one can hardly
sweep the net over bottom vegetation without getting two
or three of them. They are oval, very convex, and their
general color is brown irregularly spotted with yellow. On the
wing-covers are rows of small punctures (Fig. 204). The
coxae of the hind legs are plate-like and so large that they
conceal the basal part of the legs. According to Dr. R.
Matheson who has published a study of the whole family,
the adults feed almost exclusively on filamentous algae, par-
ticularly Nitella and Chara . About forty species of Haliplidcs
have been found in our fauna; the species most commonly
seen belong to the two genera, Haliplus and Peltodytes, both
of which are widely distributed.

Haliplids begin to mate in early spring and lay their eggs

265

FIELD BOOK OF PONDS AND STREAMS

Fig. 204. — Crawling water-beetles, Haliplus riifi-
collis: I, dorsal view of adult; 2, ventral view of adult
showing the coxse which cover the bases of the legs ;
3, larva which breathes air.

in the latter part of April, Alay and June. Females of
Peltodytes attach their eggs to aquatic plants, mainly Char a
and Nitella, while Haliplus riificollis places its eggs within
the dead cells of Nitella.

Fig. 205. — Larva of Peltodytes, showing the long
spine-like gills through which it takes oxygen from
the water. (From Wilson and Matheson.)

The larvae of both genera feed upon algae and are abundant in
the meshes of Spirogyra through which they creep very slowly
or in which they more often lie inert. They are stiff, dead-
looking objects very easily mistaken for frayed twigs. Larvag
of Haliplus (Fig. 204) breathe air through the spiracles or open-
ings in the air-tubes; Peltodytes takes ox\'gen through long
jointed spines (Fig. 205) which are supplied with air-tubes.

Predacious diving-beetles, Family Dytiscidae. — The dytis-
cids are the dominant family of water-beetles. The adults
hang head-downward from the surface of quiet waters, and

266

AQUATIC INSECTS

although no insect looks more gentle and satisfied, none is
more fierce and voracious.

They abound in ponds and pools and in the weed-grown
side waters of streams. Some are only a few hundredths of
' an inch, others are an inch and a half long. Among them are
some of the largest insects which live in the water, but, big
and little, they constitute a population of blood-thirsty pred-
atory animals.

They are black or brownish-black, often marked with dull
Yellow, and have slender thread-like antennae (Fig. 209).
By these they can be distinguished from the hydrophilids,
another large family of beetles, whose antennae are club-
shaped and carried hidden in a pocket when they dive (Fig.
212). In some genera the males have clinging organs on the
front feet; these are pressed down upon the smooth wing-
covers of the female and act as clasping organs during mating
(Fig. 208 and Fig, 209). Like many other water-beetles
dytiscids have flattened hind legs which they use in swimming.
Before diving they lift their wing-covers allowing air to enter
the space beneath them into which their spiracles open. This
is their diving supply and with it they can remain under water
a long time.

Eggs. — The females puncture the surfaces of submerged
leaves and lay their eggs singly in the plant tissues.

Larvae. — The larvae are the water tigers, a truly descriptive
name for them and their habits (Fig. 209)-; When a water
tiger catches sight of a promising young dragonfly it immedi-
ately rears up and stands at rigid attention with wide open
mandibles. When the dragonfly comes near enough the beetle
lunges forward and clutches its prey between its sickle-shaped
jaws. These jaws are hollow and with its mouth still closed,
the beetle can suck the body juices of the dragonfly while
still keeping its firm clutch. It breathes air and has a pair
of spiracles at the rear end of its body which it thrusts up
above the surface whenever it comes to the top.

267

A

FIELD BOOK OF PONDS AND STREAMS

Collecting, aquarium study. — Diving beetles forage in the
populous shallows near shore and are easily collected there
by sweeping the plants with a net. Both larvae and adults
are interesting aquarium animals but they must be kept well
supplied with live food. Harris kept an adult Dytiscus
"three years and a half in perfect health in a glass vessel
filled with water, supported by morsels of raw meat. "

t

Fig. 206. — A common medium-sized diving beetle,
Aciliiis: i, adult; 2, larva (from Wilson).

Acilius. — This is the commonest of the medium-sized diving
beetles. The adults (Fig. 206) are about one inch long, dull
3^ellowish-brown with yellow margins on the thorax and
wang-covers, each of which bears four furrows. The larvae
(Fig. 206) are easy, graceful swimmers. When they are
resting below the surface the body is curved in a crescent,
usually around a plant stem, and whenever they let go they
are buoyed upward, tail foremost, by the air within their air
tubes. Sooner or later they hang head down with tails thrust
through the surface film.

In the larvas of Acilius the prothorax is considerably longer
than wide.

Coptotomus. — Unlike Acilius this larva (Fig. 207) is not de-
pendent upon air and it is always found prowling on the bot-

268

N

AQUATIC INSECTS

Fig. 207. — Diving beetle, Coptotomus interroga-
tus: I, larva (from Wilson); 2, adult.

torn, breathing by means of its tracheal gills which trail off
from the sides of the body. It is usually a half inch long.

Fig. 208. — Diving beetle, Cyhister: i, larva (from
Wilson); 2, adult male; 3, underside of his front
tarsus, showing the roughened surface which is
pressed against the back of the female in mating.

269

A

FIELD BOOK OF PONDS AND STREAMS

Cybister. — Cyhister (Fig. 208) is a genus of large and very
voracious water tigers. The fullgrown larva becomes 3
inclies long and will attack tadpoles, other water-beetles, and
small fish.

When larvae come to the surface to breathe, they do not
hang head downward like Acilius and Dytiscns but the head
and thorax are both held near the surface. Their narrow
necks are also good distinguishing marks.

<^ ^

Fig. 209. — Large diving beetle, Dytiscns: i, adult
male; 2, underside of his front tarsus (cf. Fig. 208);
3, larva clutching damselfly nymph.

Adult dytiscid beetles (Fig. 209) are nearly an inch and a
half long and the full-grown larvas may measure three inches.
The adults are dark brown with a dull j^ellow stripe along the
sides of the thorax and wing covers. When at rest they hang
head downward with the tip of the body projecting through
the surface film.

The Iar\'£e (Fig. 209) also hang head downward with their
tails thrust through the surface film for air. Much of the
time they clamber about through the vegetation of the shal-
lows and frequent the tadpole resorts; here they clutch the
soft side of the tadpoles, sucking the body juices until only

270

AQUATIC INSECTS

their puckered skins remain. The shallows where tadpoles sun
themselves are almost sure to swarm with dytiscid larvas
whose appetite for tadpoles is a serious menace to the amphib-
ian population. Neither adult nor larva of Dytiscus hesi-
tates to attack an animal much larger than itself. There
are records of an adult Dytiscus in an aquarium, which de-
voured seven snails, Lymnaa stagnalis, during one afternoon
Whirligig beetles, Family Gyrinidae. — Whirligig beetles are
one of the most easily recognized of all brook insects. With
the first spring days they come to the surface in twos and
threes, from their winter hibernation, and soon gather in
companies on the surface of still or gently running water,
resting motionless or circling round and round each other
(PI. X). They are blue-black or bronze, oval, and flattened;
some are canoe-shaped on the ventral side and so smooth that
they cut through the water with the greatest ease. Their
hind legs, paddle-shaped and fringed with long hairs, are
used oar-like in their rapid sculling (Fig. 210, 2). The com-
pound eyes are divided by the sharp margin of the head so
that in effect there is one eye for looking up from the water
and one for looking down into it (Fig. 210).

1 a.

Fig. 210. — Smaller whirligig beetle, Gyriniis: I,
adult, dorsal side; 2, ventral side showing the middle
and hind legs which fold tightly down to the surface ;
3, side of head with divided eye.

Gyrinids are more difficult to catch than would first appear.
Though circling all about one they can evade a net with surpris-
ing agility and even after they are caught in it they frequently

271

FIELD BOOK OF PONDS AND STREAMS

spring from it before they are landed. When handled they
give off a milky fluid with a peculiar odor. In aquaria the
males often make squeaking noises b}'' rubbing the under-
sides of the wing-covers against the body.

There are two common genera of Gyrinidce, Gyrinus in-
cluding the smaller whirligigs (Fig. 210) and Dineutes, the
larger whirligigs (Fig. 211).

Adults of Dineutes which are kept in captivity will devour
with avidity any freshly killed larvae. Wilson fed these to
whirligigs which he was observing and writes, "As many as
could would seize the insect, crowd around it, grasping it,
whirling around it in wild curves and sometimes diving be-
neath the surface, but always holding on to their prey and
tearing out mouthful s of insect tissues."

Their oval white eggs are laid on the under surfaces of
lily pads (Fig. 18), or on Potamogeton leaves. Each egg is
glued separately to the surface of the leaf.

Larvae of whirligigs. — The larvae of some insects, such as
caddis worms, are very familiar, while adults are almost un-
known, but this situation may be quite reversed. Thus among
the whirligigs the adults are often seen, but the larvae almost
never. They are pale, slender creatures which crawl over the
bottom trash or swim through the water with a sinuous motion
of their bodies which is aided by eight heavily fringed gills
which hang from each side of the abdomen. They are adepts
at clambering backwards or forwards. On the tip of the
abdomen there are four sickle-shaped hooks which they catch
into anything convenient and pull themselves backward
after the manner of caddis worms.

Whirligig larvae capture young mayflies and dragonflies but
they are less rapacious than some of their reb.tives. They
can be kept in aquaria and will thrive on nymphs of the may-
fly, CallihcEtis (p. 208). In Gyrinus larvae (about one half
inch long) the first two pairs of gills are fringed like the others,
in the larger Dineutes (one inch) these two pairs are with-

272

AQUATIC INSECTS

!

Fig. 211. — Larvae of whirligig beetles: i, Gynnns
(from Kellogg after Schiodte); 2, Dineiites (after
Wilson) .

out fringes; otherwise the larvse of the two genera are
similar. '

Pupae. — When fullgrown the whirligig larva crawls out on a
moist bank and its gills shrivel up except for the last three
pairs, which persist and seem to be used in locomotion. The
pupating Dineutes observed by Wilson made pupal cases
from pellets of earth stuck together with" saliva. The full-
grown larva selected a reed or grass blade near enough to the
ground so that it could reach the earth, then hanging itself
up by its posterior hooks it built a case round itself, repeatedly
stretching downward to grasp a mouthful of dirt, sometimes
taking a stick or leaf with it. When finished the pupal case
is about half an inch long and the full-grown larva is folded
up in a C-shape within it.

Water scavenger beetles, Family Hydrophilidae. — In the
same protected water with the dytiscid beetles are other large

273

FIELD BOOK OF PONDS AND STREAMS

black beetles — the hydrophilids or water scavengers — which
look and act very much like them.

Adults. — But although they are similar there are several
ways in which the adults of these two families can be distin-
guished. H^'drophilids hang at the surface with heads up
(Fig. 212), dytiscids hang with heads down (PI. X). Hydro-
philids have very short club-shaped antennae and long
slender palpi which may easily be mistaken for antennas
(Fig. 212, 2), dj^tiscids have slender thread-like antenna
(Fig. 209). When adult hydrophilids come to the surface,
they thrust their antennae through the surface film and pull
back a bubble of air which spreads over the ventral surface
of the body like a silver blanket.

Eggs and larvae. — They lay their eggs in beautiful silken
cocoons, often fastened beneath floating leaves of water
plants (PI. XVII). Sometimes the cases are carried beneath
the mother's body. They are all waterproof and contain
about a hundred eggs but the young larvae eat one another so
lustily that the final crop is reduced.

Fig. 212. — Water scavenger, Hydrophilus:
adult, ventral side; 2, larva, dorsal side.

I,

274

AQUATIC INSECTS

Hydrophilus. — These are medium-sized black beetles on
which there is a sharp spine in the middle of the thorax which
projects backward between the legs (Fig. 212). The adults
appear to feed entirely upon algae. The young larvs live
on small entomostracans, later they eat tadpoles, insect larvae
and other beetles. They come to the surface to breathe.
Projecting from the sides of the abdomen are seven pairs of
filaments (Fig. 212), but these do not function as breathing
organs. Fullgrown larva, a little more than half an inch long.

Fig. 213. — Berosus: i, adult, and 2, larva showing
long gills (after Wilson).

Berosus. — The adults are small, yellowish beetles (Fig. 213) ;
both adults and larvse feed upon green algse. Wilson writes
of one species, "These larvae are very sluggish; they cannot
swim at all but crawl about slowly over the" vegetation, their
long tracheal gills standing out rigidly on either side like rods.
They cover themselves with green algae and lie inert for hours
at a time, only coming out after f ood. ' ' They breathe through
their lateral gills, which contain tracheae (Fig. 213), and do not
need to come up for air like Hydrophilus. Wilson kept larvas
in an aquarium for a long time, supplying them with small
crustaceans, yet they would take nothing but vegetable food,
algae, Chara and Nitella. He found them very hard to kill,

275

PI, XVII. — Eggs of water insects: i, mayfly, Siphlnriic^
eggs containing embryos, shells with slit through which
insects have hatched; at the center note the head projecting
from a shell; 2, mayfly, Siphhirus, with shell from which it has
hatched; 3, eggs of horse-fly, Chrysops, on an iris leaf; 4, eggs
of caddis fly, TricBnodes, on underside of lily pad ; 5, egg cocoon
of hydrophilid beetle, on underside of lily pad.

Photo, by A. H. Morgan

PLATE XVII

AQUATIC INSECTS

able to live from an hour to an hour and a half in ninety -five
per cent alcohol. This larva is about three eighths of an inch
long.

Fig. 214. — Tropisternus lateralis: i, larva (after
Wilson); 2, adult.

Tropisternus. — This medium-sized shiny black beetle (Fig.
214) abounds in nearly all beetle habitats, where it is often
by far the commonest kind to be found. The adults are
adepts at every kind of locomotion except jumping and ailb
thus agile even on land. They are thorough vegetarians,
living entirely upon algas.

Wilson characteristizes the larva of Tropisternus lateralis
(Fig. 214) as follows: "Its exertions when eating demand a
constant air supply, and it usually seizes its, prey and swims
to the nearest water plant. It then backs up the stem,
dragging its prey after it until it can thrust its abdomen above
the surface. It can thus eat and breathe at the same time,
and it is engaged in doing both nearly all the time. ... It
is the very personification of voracity and gluttony and will
eat any kind of an insect or larva that it can overpower."
Usual length, one half inch.

Riffle-beetles, Family Psephenidae. — The lar\^as of riffle-
beetles live in rapid currents, a habit which is rare among

277

y.

FIELD BOOK OF PONDS AND STREAMS

beetles. On hot days the adults (Fig. 215) settle on stones
projecting from the midcurrents of rushing streams. They
are small, about a quarter of an inch long, and their bodies
are covered with silken hairs. These hold the film of air
which blankets the female when she climbs down over the
water-washed stones to lay her cluster of yellow eggs in the
swiftest part of the current.

7 SL ^

Fig. 215. — P sephenus lecontei: i, adult; 2, its larva,
the water penny, dorsal side; 3, ventral side.

The common eastern species, Psephenus lecontei {Psephen-
idcE), is knovv^n mostly by its larvas, for which Comstock
ft-st suggested the fitting name of water penny (Fig. 215).
These flat, copper-colored larvas cling tightly to the dark
under surfaces of water- washed rocks, and even when the
rocks have been upturned and they are right under the eye
they may not be seen at all. Only when the}'' are turned over
on their backs do water pennies display their legs and their
five pairs of glistening white gills (PI. VIII). Water pennies
may be found in shallow riffles all the year round, where they
feed upon the algal film on the stones (PI. I).

The leaf-beetles, Family Chrysomelidae. — In this large fam-
ily of terrestrial leaf-eating beetles two subfamilies, the
DonaciincB and Galerucincs, feed upon water plants. The
commonest of these belong to the genus Donacia.

Donacia. — The larvae of Dojtacia feed upon the under-
ground stems of various water plants such as the yellow water-

278

AQUATIC INSECTS

liiy, water-plantain, and Potamogetons, and all have a similar
life-histor\\ Only the adults and eggs are easily found.
Their entire life cycle is still another example of the way in
which insects though living several feet under water still
contrive to breathe air.

Fig. 2 1 6. — Leaf -beetle, Donacia palmata, laying
her eggs on the underside of a lily pad through a
hole which she has cut. Length of adult, one half
inch.

The long-homed leaf-beetles of the genus Donacia can be
seen about ponds on any bright summer da}^ walking over
the lily pads, flying up into the air and returning again to the
lilies. They gleam in the sunshine with metallic green, or
bronze, or purple against the dark lily leaves. The under
sides of their bodies are pale brownish, and clothed with silky
hairs which keep them from getting wet. They hold their
long antennae arched downward in front of them, busily feel-
ing the leaf surfaces wherever they walk over them.

In ponds where these beetles are abundant the lily pads
are riddled with holes where they have laid eggs (Fig. 216).
When a female is ready to lay her eggs she stands on the upper
surface of the leaf, bites a hole in it about one-quarter of an
inch in diameter, inserts her abdomen through the hole and
lays her eggs in a circle, often an incomplete one, on the under
side, placing a double row of eggs in each circle and fasten-
ing them to the leaf by a gelatinous glue (Fig. 217). These

279

FIELD BOOK OF PONDS AND STREAMS

Fig. 217. — Eggs oiDonacia glued to the underside
cf a lily pad around the hole which has been cut by
the beetle.

conspicuous white egg-clusters are easy to find upon most
lily pads all through the summer and early fall.

In about ten days the eggs hatch and the larvae begin a re-
markable existence in which, though living two feet or more
below the surface, they constantly breathe air. Dropping
down through the open water these larvae seek the under-
ground stems of the plant on which their own species of
Dofiacia has lived for generations. When the stems of aquatic
plants are broken beneath the water a flood of air bubbles
comes pouring to the surface from the air spaces within them.
The little Donacia larvae rasp their spines against such stems,
break through the walls of the air spaces, then push their
heads into the holes they have made (Fig. 218). Thus, the
larva taps the air suppl}^ of the plant and its head and thorax
are surrounded by a layer of continually escaping air. Alac-
Gillivray and others found stems with dozens of little Donacia
larvae hanging to them feeding upon the plant tissues, and all
breathing air, though they were three or four feet below the
surface of the water.

When fullgrown the larva spins a water-tight cocoon pro-
visioned with air from the air spaces of the plant. When the
adult emerges from the cocoon at the end of pupation, some
of this air catches in the silken hairs on the ventral side of

280

AQUATIC INSECTS
blant stem

Fig. 2 1 8. — Larva of Donacia palmata with its head
thrust into air space in a Hly stem, breathing air
though three feet under water (after MacGilHvray) .

its body, buoying it up, and at the same time furnishing it with
a breathing supply sufficient for it until it reaches the surface
of the water.

as

Fig. 219. — Galerucella nymphcBa: i, larva; 2, adult;'
3» eggs.

Galerucella nymphaea. — This genus also lives mostly upon
water-lilies but its whole life is spent above the surface of the
water. The adults (Fig, 219) have indistinctly striped wing-
covers; the females lay small clusters of shining yellow eggs
on the upper surfaces of yellow pond-lily pads. The larvae
(Fig. 219J, a little more than a quarter of an inch long, are
black with fine whitish lines and spots. They feed on the
leaf tissues until they are fullgrown and then pupate, often
upon the same leaf.

281

FIELD BOOK OF PONDS AND STREAMS

Flies — Diptera

Flies have but one pair of wings, front ones, the second pair
being represented only by little clublike projections called
halteres. Flies include the familiar houseflies and mosqui-
toes. Dragonflies, mayflies, stoneflies, caddis flies and the
like have four wings and are not flies. Flies undergo a com-
plete change of form in larval, pupal, and adult stages. The
Diptera form a vast group both in numbers of species and
individuals, more than twelve thousand species having been
found in North America.

Among them are many families whose larvas are aquatic
and a few whose pupae are also aquatic. These include the
gnats, punkies, midges, mosquitoes, horseflies, and craneflies.
The worm-like larvse are of diverse forms and sizes ; thousands
of midge larvae are no longer than a quarter of an inch while
some of the cranefiy larvae are more than two inches long.
The pupae may live in the water as do the midges and mosqui-
toes or in damp places near the water like many of the crane-
flies. Although the adults fly about in the region near water
they are by no means confined to it. All adult flies suck their
food through their tube-like lower lip or labium.

The habits of the aquatic flies are so various that they are
best considered by separate groups.

Identification. — Key to families of Diptera larvas from man-
uscript key by Dr. C. P. Alexander (slightly modified).

Key to Diptera

Laiva&

1. Caudal end of body prolonged into a long extensile

breathing-tube; rat-tail maggot and similar types. 2
Caudal end of body not prod,uced. 3

2. Head forming a complete non-retractile capsule.

Phantom craneflies, PtychopteridcB, p. 287
Head reduced, capable of retraction within the body;
true rat-tail maggots.

Syrphus-flies, Syrphidce, p. 299

282

AQUATIC INSECTS

3. Head-capsule complete, not retractile into thorax, — i. e.

encephalous. 4

Head-capsule incomplete, capable of retraction within

body. 7

4. Body depressed, subdivided into six primary divisions,

each with a ventro-median sucking disk, with a tuft
of gills on either side.

Net- veined midges, BlepharoceridcE, p. 297
Body not as above. 5

5. Thoracic segments fused into a complex mass, without

prolegs; in most genera with an anal respiratory funnel.

Mosquitoes, CulicidcE, p. 293

Thoracic segments not so fused ; if conspicuously dilated

or extended, provided with a median prothoracic

proleg. 6

6. Body with conspicuous anal gills, or else long, slender

and snakelike {Culicoides); no mouth-fans or caudal
sucking disk. Midges, ChironomidcE, p. 289

Body not as above, the abdominal spiracles small but
distinct ; body club-shaped ; mouth with fans ; a sucking
disk on the club-shaped posterior end of body.

Black-flies, SimuliidcE, p. 296

7. Head massive, incomplete behind; mandibles moving

horizontally or obliquely across the mouth-opening;
labial plate well developed.

Cranefiies, (Tipuloidea), p. 283

Head-capsule reduced, more or less retractile: mandibles

moving vertically across the mouth-opening; labial

plate not developed. 8

8. Body depressed, spindle-shaped, the surface finely

shagreened; head little retractile; spiracular fissure
transverse; pupates in last larval skin.

Soldier-flies, StratiomyiidcB, p. 299

Body cylindrical, the abdominal segments with a girdle

of pseudopods on each segment; body-surface usually

longitudinally striated; head retractile; spiracular

. fissure vertical; pupa free, not in last larval skin.

Horse-flies, TabanidcE, p. 298

Cranefiies, Superfamily Tipuloidea. — Cranefiies are the
large mosquito-like insects which rest on the streamside

283

FIELD BOOK OF PONDS AND STREAMS

shrubber>% are caught in the spider webs of bridge railings,
or dance in swarms over streams at twiHght. They fly about
lamps, and into houses, where they are famiUar as long-legged
flies which flutter into the corners of window panes and lose
a leg with every new trouble that comes into their lives.

Adults. — Craneflies are long and slender, — body, wings,
and legs, especially the legs; they are the "daddy-long-
legs" among flies. Just behind the wings are their clublike
halteres or rudimentary hind wings. They seem to live
mainly on the nectar of flowers but they take little food of
any kind. In many species there are mating swarms, in most
cases largely made up of males. The males of some species
emerge before the females, seek out the female pupse, and wait
there, immediately mating with the adult females when they
come out of the pupal covers. Craneflies usuall}'- fly about
while mating, the females pulling the males after them. They
lay their eggs in the water, flying over it and making sudden
and frequent drops to dip the tip of the abdomen in the surface.

Certain craneflies like Dicranomyia can often be seen
bobbing, a setting-up exercise widely practiced among crane-
flies. They stand firmly on the ground, springing on their
legs and bobbing their bodies up and down. They may do
this for a long time and some craneflies manage to eat during
the performance.

Larvae. — Cranefly larvas are brown or white skinned, often
so transparent that the coils of their air-tubes can be clearly
seen from the outside.

In Epiphragma the smaller, pointed end is the head and when
this is extended the brown biting mouth parts are conspicuous ;
but it is often kept withdrawn into the thorax so that they
do not show at all. Larvae of A ntocha have anal gills (Fig. 223)
and all of their oxygen supply is obtained from the water
but with this single exception cranefly larvae breathe air
through two spiracles at the hind end of the body. Thess
are surrounded by six to eight fleshy lobes, often lined with

284

AQUATIC INSECTS

Fig. 220. — A typical cranefly, EpipJiragma: i,
larva which lives among water soaked leaves; 2, pupa;
3, adult.

dark horny plates. This bizarre tail-piece, known as the
spiracular disk (Fig 221), is thrust up to the surface of the
water for air.

Fig. 221. — Spiracular disk, the tail-piece with
openings of air-tubes which Epiphragma thrusts up
for air. (From Alexander.)

A favorite place for cranefly larvae such as the common
Epiphragma (Fig. 220) is among the water-logged sticks and
leaves which catch here and there in riffly brooks; others like
Antocha (Fig. 223) live in very rapid water; still others like
Pedicia (Fig. 226) are found in springs. Very many of the
larvae are only semi-aquatic, living in moist places in meadows,
in shady woodlands, in damp moss, and in decaying wood.

285

FIELD BOOK OF PONDS AND STREAMS

Food. — The majority of the larvae feed upon leaves and root-
lets, diatoms and filamentous algas. Others like Limnophila
are carnivorous, feeding on blood-worms and small insects.

Pupae. — When they are ready to transform, the larvae become
sluggish, quit eating, and transform into pale colored pupae.
Most cranefiies go on shore to pupate, burrowing in loose,
damp soil, and remaining there for about a week before the}"
emerge as adults. The following interesting account of their
emergence is given by Alexander in "The Cranefiies of New
York " (Bibliography, p. 420), "The emergence of the adults
usually takes place during the late hours of the morning, the
greatest number emerging between ten o'clock and noon.
When ready to emerge, the pupa pushes part of its body out
of the earth, the posterior two-thirds or half remaining at-
tached to the soil. If it projects farther than this, its trans-
formation seems to be a very difficult operation. The pupa
bends backward and forward constantly, flexing the body
dorso-ventrally. This motion appears to exhaust it, since it
frequently rests. The skin splits lengthwise up the mesonotum
(middle section of back of the thorax) and the adult emerges.
. . . The drawing out of the extreme tips of the antennas
is usually accomplished by the insect flexing its body back-
ward. When the antennas are freed, the insect walks a few
steps from the cast skin, withdrawing its abdomen from the
case."

Hibernation. — Cranefly larvae can be found in brooks all
through the winter (PI. I). Alexander states that "it is
probable that nearh' all cranefiies in the north temperate
zone winter normally as larvce."

Associates. — Cranefiies have many enemies in every stage
of their careers. The adults are poor fliers and are devoured
by many birds from water-fowl to warblers, by amphibians,
by spiders, and by other insects, especially dragonflies.
Pupae and recently emerged adults are seized by running
spiders; larvae are devoured by trout, by frogs and salaman-

286

AQUATIC INSECTS

ders, and by birds, the sandpipers, woodcocks and wading-
birds.

Identification. — The Superfamily Tipuloidea contains
four families, the primitive craneflies, TanyderidcB; phantom
cranefiies, PtycJiopteridce; "false" craneflies, AnisopidcB; and
the typical craneflies, Tiptdidce. Members of only two
families are mentioned here.

Fig. 222. — A cranefly with balloon feet, Bitta-
comorpha clavipes: i, adult; 2, larva.

Phantom craneflies, Family Ptychopteridae. — One of the

most striking members of this family is Bittacomorpha clavipes,
a phantom cranefly with black-and-white-banded legs (Fig.
222). When these craneflies are mating the female flies
ahead trailing the male after her. Their feet work like those
of the winged Mercury but by a different device. The tarsi
or feet of Bittaco?norpJia are pillowed out by sacs and tubes
containing air, which buoy it up as it drifts in the wind relying
upon wind currents as well as any modern glider. Alexander
has quoted the following letter written to him b}- Dr. J. G.
Needham: "A breeze was blowing up the gorge, and on the
breeze a Bittacomorpha was drifting rapidly upward in the

287

FIELD BOOK OF PONDS AND STREAMS

usual flight attitude with broadly outspread legs, the swollen
metatarsi hanging vertically, all phantom-like in slenderness
and in strongly contrasting black and white. It came from
below the level of the rail, swept past within two feet of my
face, and passed on upward with the breeze until lost to view,
perhaps lOO feet higher than the bridge, and much farther
upstream. Since the creature can fly only very slowly and
here was moving several times faster (I could not see whether
it was using its wingsj, it was obviously drifting in the wind.
Perhaps this is a normal function of the expanded metatarsi."

The rusty red larvae live in shallow water filled with de-
cayed vegetation, among which they lie with the breathing
tube pushed up through the surface film (Fig. 222). Like
the larva, the pupa rests beneath the water with its air-tube
at the surface. The larva becomes an inch and a quarter long.

Common and widely distributed in eastern North America.

Typical cranefiies, Family Tipulidae.— This is by far the
largest family of cranefiies, containing nearly 3000 species
found in most parts of the world.

Fig. 223. — A swift-water cranefiy, larva of
Antocha.

Antocha. — The lar\^a of Antocha (Fig. 223) is found upon
stones in rushing torrents. There it lives in a crevice or
among pebbles within a silken case one to two inches long and
open at both ends, breathing through its four tracheal gills
and the tracheae of its caudal lobes. The pupa lives in the
case previously used by the larva, its head always pointing
downstream. Distributed over the northern hemisphere.

Fig. 224. — Larva of Helius {RJiaynphidia) .

288

AQUATIC INSECTS

Helius. — One "species (Fig. 224) of the genus Helius, form-
erly called Rhamphidia, is a common inhabitant of cat-tail
marshes where it lives near the surface among floating leaves
and refuse. Length of larva, about a half inch.

Fig. 225, — A carnivorous cranefiy, Limnophila.

Limnophila. — The lar\^as of Limnophila (Fig. 225), agile and
snakelike in their movements, are among the most carnivo-
rous of all cranefly larva;. They live in water-soaked muck
rather than in open water; some burrow in damp soil.

Length of larva, about half an inch.

Fig. 226. — Larva of Pedicia.

Pedicia. — ^The common eastern species, Pedicia albivitta
(Fig. 226), is a dweller in cold springs throughout the north-
eastern United States and Canada.

Length of larva, one inch and a half.

Giant cranefly, Tipula abdominalis. — This is a ver>' large
and very common cranefly. The larva;, often more than tvro
inches long, are abundant among the water-saturated, decay-
ing leaves of little streams and are frequently turned up with
such litter in midwinter collecting (PI. I). They are her-
bivorous, feeding chiefly upon diatoms and decayed plant
tissue.

Midges, Family Chironomidae. — On late afternoons in
spring, swarms of little flies disport themselves in the sun-
shine. They fly low, catching on clothing and gathering in
the corners of window panes; in the evening they swarm
around the lights. They are midges belonging to the family
Chironomidce, minute, delicate flies which are mosquito-like

289

J.

FIELD BOOK OF PONDS AND STREAMS

but of daintier build and of generally less offensive habits,
though the family includes the punkies, abundant along moun-
tain streams in the Adirondacks and White Mountains and
sometimes at the seashore.

Adults. — Adult chironomids are seldom half an inch long
(Fig. 228), sometimes confused with mosquitoes but a hand-
lens will show that the wing-veins of mosquitoes are covered
with opalescent scales (Fig. 227) while those of the chironomid

Fig. 227. — Wings of i , chironomid midge with bare
wing-veins; 2, mosquito with wing-veins covered
by scales.

midges are bare or merely hairy (Fig. 227). When they are
resting on a surface chironomids hold their front feet up,
mosquitoes keep their front feet down and their hind feet up.
In numbers and distribution the family Chironomida is a very
successful group; like the related family, CulicidcE, the mos-
quitoes, they are known from Greenland to the tropics and
there are more than twelve hundred species, most of them so
similar that they can be distinguished only by specialists.

Eggs.— Some of them lay their eggs in strings of jelly coiled
and snarled on stones in swift flowing water (Fig. 23,) ; others
deposit them near the surface of the water in quiet pools.
The eggs themselves are white, usually oval, pointed at both
ends, and though each egg is a mere dot to the eye they some-
times occur in such masses that their total bulk runs into

quarts.

290

AQUATIC INSECTS

Larvae. — Midge larvae occur in vast numbers in all fresh
waters. They are slender and wormlike, with fleshy prolegs
at each end of the body, and they arch their backs like measur-
ing worms (Fig. 228). Many of them cover themselves with
soft dirt tubes (Fig. 19). Networks of these tubes cover the
litter of dead leaves in the pools, and the sides of a collecting
dish where the "catch" has stood for two or three hours.
They are fragile and never portable like those of the caddis
worms but new cases are made whenever the larvas are forced
out of the old ones.

Midge larvae feed entirely upon algae and decayed vegeta-
tion. On this plentiful food supply they thrive in vast num-
bers and constitute food for larger animals, the predacious
insects, the young of fishes and other carnivores. They
constitute a staple fish-food; it has been said (Carman) that
no other one genus of insects constitutes as important an
item in the food of so large a number of fishes.

Fig. 228. — The midge Chironomus: i, larva; 2,
pupa; 3, adult.

291

FIELD BOOK OF PONDS AND STREAMS

Pupae. — These live in the water and breathe air Hke mos-
quito pup£e. In all of them there is a large thorax from
which the pair of air-tubes projects up like ears (Fig. 228).

Chironomus. — Chironomus larvs live in tubes on the sur-
face of the mud in pools. The best known ones are brilliant
red, and are called blood-worms, their prolegs (Fig. 228) dis-
tinguishing them from the true worms, Tubifex, that are also
called blood-worms. Larvae of Chironomus have prolegs on
the first and twelfth segments of the body, and on the eleventh
there are two pairs of long "blood-gills," thin-walled sacs
into which blood can flow freely (Fig. 228). Larvas of various
chironomids are from an eighth of an inch to an inch long.

The eggs are laid in strings of jelly, in which they are set
in patterns characteristic of the species.

Fig. 229. — Midge, Cidicoides, called "punkies":
I, larva; 2, adult.

"Punkies," Culicoides. — In Maine the Indians call these
midges "No-see-ums. " There are great numbers of these
biting flies in the northern forest country. A trader's expe-
rience at a lodging house on the Kippewa River in Quebec is
one of many. The lamp had been left lighted in his room for
several hours, and the flies had gathered on all white covers
and formed "literally a blanket of punkies upon his bed."

Adults of Culicoides (Fig. 229), Ceratopogon, and several
other allied genera of the Chironomidce share the same com-

292

AQUATIC INSECTS

mon names, "punkies, " "sand-flies," or others according to
the locality. They have very robust legs, and the thorax
is low, not humping up above the head.

As in Chironomus, larvse and pupae are both aquatic. The
larvae, swim with a snake-like motion, are whitish, slender
and i2-segmented, with delicate, white blood-gills which can
be retracted into the hind end of the body (Fig. 229).

Mosquitoes, Family Culicidae. — Compared with related
groups of flies this is a small family including only about a
thousand species. However, it is an important one because of
the trouble it makes. The habits of mosquitoes have made
them familiar to everybody and much study has been devot-
ed to them because of the association of certain species with
malaria and yellow fever.

Some species of mosquitoes attack man and other mam-
mals, a few attack birds only and many species do not suck
blood at all. It is only the females which bite or suck blood;
the males live on fruit and plant juices. The males can be
recognized by their plumose antennas. One of the most
characteristic things about mosquitoes is the structure of their
wings, which have a thick fringe of opalescent hairs and
scales along their margins and on the veins (Fig. 227).

Larvae. — Although they live in the water, all mosquito larvag
breathe air and are commonly known as wrigglers because
of their swimming motions (Fig. 34). In ail of them the head
and thorax are large; the abdomen is slender with openings
of air-tubes at the tr?-il end. Mosquito larvse are continually
wriggling back and forth from surface to bottom where they
feed on minute plant and animal cells and on submerged
plants; a few are predacious (Fig. 230).

Pupae. — A mosquito pupa is shaped like a question mark;
the air-tubes open from its thorax, comparable in position
to the top of the question mark. Mosquito larvae lie parallel
to the surface film or hang tails up but the pupas hang with
their backs up (Fig. 232).

293 '

FIELD BOOK OF PONDS AND STREAMS

Eggs. — The eggs are laid in almost any standing water, a
lake, rain barrel, roadside puddle, or in marshes. In some
species the eggs hatch very soon, in others not for a long time;
probably many common mosquitoes pass the winter in the
egg stage, hatching with the first spring warmth. Under
favorable conditions our common mosquitoes go through
their life cycle from egg to egg-laying adult in a short time.
Mosquitoes can get along under difficult conditions of drought,
cold, and starvation. They can live virtually anywhere,
which accounts for their great numbers and for their wide
distribution.

Pig. 230. — A carnivorous mosquito, the phantom
larva, Chaobonis (CoretJira).

Phantom larvae, Chaoborus (formerly Corethra) . — This is a
group of mosquitoes not usually known as such because they
do not suck blood. Their larvae are the phantom larvae of
glass-like transparency, the only insects which are regularly
found in the plankton or floating population of the open
water. They are a half inch long, recognizable by the
prominent, dark air-sacs, one pair at each end of the body,
probably the regulators of their specific gravity (Fig. 230).
Phantom larvas are predacious, using their antennae to grasp
their prey, mainly entomostracans and rotifers.

Fig. 231. — Adult mosquitoes: i, common mosqui-
to, Cu'ex, with body held parallel to the surface; 2,
malarial mosquito, Anopheles, with body tipped
up behind.

294

AQUATIC INSECTS

Culex. — The genus Culex, common house mosquitoes, can
be recognized b}^ their hump-backs and their habit of stand-
ing with their bodies nearly parallel to the surface. Their
wings are plain colored, never spotted like those of Ano-
pheles (Fig. 231). None of this genus is known to carry
either malarial or yellow fever organisms.

They lay their eggs on the surface of the water, each egg
standing upright but glued to its neighbors so that the whole
cluster makes a floating raft (Fig. 232, i). The eggs hatch
within about three days, depending on the temperature and
the species.

Fig. 232. — ^Water phases of mosquito life: i,
Culex eggs on water surface; 2. larva; 3, pupa; 4,
Anopheles eggs at surface and egg enlarged shomng
floats at sides; 5, larva; 6, pupa.

Anopheles. — Anopheles or "malarial mosquitoes" can be
distinguished by their straight bodies which lack the "round-
shouldered hump" of Culex, their black and white spotted
wings, and their habit of resting with the hind end of the

295

FIELD BOOK OF PONDS AND STREAMS

body tipped up (Fig. 231). Anopheles eggs float singly on
the surface. When at rest Anopheles larvas always lie parallel
to the surface of the water, with the under side of the abdomen
upward so that their two short air-tubes opening from the
eighth segment can reach the air (Fig. 232).

Black-fiies, Family Simuliidae. — Thousands of these lar\^ae
make up the swaying greenish "black moss" which covers
the rocks in waterfalls and rapid streams from Alay to mid-
summer, where hundreds can be gathered at a stroke of one's
hand. This family includes the Adirondack black-fly, Prosi-
miilium hirtipes, which is a scourge along the northeastern
mountain streams in spring and early summer.

Fig. 233. — The black-fly SimuUiun: i, larva
which hangs to the rock by a caudal sucker and
collects food with its fan-shaped brushes; 2, pupa
showing tracheal gills; 3, adult. Length, larva, one
quarter inch.

Simulium. — The larva holds fast to the rocks by a sucking
disk at the hind end of its body. This frees the mouth to
take in the diatoms gathered on the fan-shaped collecting
brushes (Fig. 233, i). The fleshy proleg just behind the head
ends in a sucker like the rear one and on these two the larva
walks over the stones. If it loses its footing or is brushed

296

AQUATIC INSECTS

off the stone it hangs to its anchorage by a delicate silken
thread spun from its salivary glands; by this means too it can
travel downstream, swinging from rock to rock. Simtdiiim
larvae breathe by the three retractile blood-gills at the hind
end cf the body.

The pupal cocoons form golden brown blankets on the
rocks even more moss-like than those of the larvae. They
breathe through tracheal gills, the fringes which wave from
the top of each case. Like all swift-water insects the adults
fly as soon as they emerge, laying their eggs shortly afterward
(Fig. 233). Black-fly larvae are eaten in large numbers by
fishes. Adult black-flies are pests both to human beings and
animals, and black-fly cream and other repellents are sold all
through the country where they abound. The Maine fisher-
men grease their hands and faces with kerosene oil and mutton
tallow. Black-flies are active only during the daytime, leav-
ing twilight to the mosquitoes and punkies.

Net-veined midges, Family Blepharoceridae, larvae. — The
larvae of Blepharocera cling to the stones in the rapids of
mountain streams, in the waters of ravines, and in rushing
brooklets. In their own special haunts they are abundant
and no member of waterfall society is better equipped with
holdfasts.

Clinging to its stone it looks like a row of six little black
beads, Jess than half an inch long, the first bead consisting of
the fused head and the thorax, the other five representing
the abdomen (Fig. 234, i). It has no feet, but down the mid-
ventral line is a row of six sucking disks which it uses in
walking and clinging (Fig. 234, 2). It breathes by means
of the tufted tracheal gills on each segment.

Pupae. — The pupae are egg-shaped with a pair of ear-like gills
at the large anterior end (Fig. 234).

Adults. — The adult females of some exotic tropical species
are blood-sucking but the majority, including our North Am-
erican forms, are not. Abundant in May.

297

FIELD BOOK OF PONDS AND STREAMS

Fig. 234. — Net-veined midge, Blepharocera: i,
larva, dorsal side; 2, ventral side showing gills and
the six suckers by which it clings to the stone; 3,
pupa showing gills; 4, adult.

Horse-flies, Family Tabanidse. — Tabanid larvae (Fig. 235)
live in stagnant, scummy water close to shore, sometimes in
damp earth. They are half an inch long, whitish and worm-
like, taper at both ends, and have roughened ridges running
around the body. They breathe air usually through a pair

uJJiJ^*^

Fig. 235. — Horse-fly, Chrysops niger: i, larva
showing openings of air-tubes; 2, adult.

298

AQUATIC INSECTS

of openings at the hind end of the body, though there may be
a pair at each end. They are predacious upon snails and in-
sect larvse.

Adults. — The adults are (Fig. 235) the once familiar horse-
flies, now more frequently found on cows. Only the females
are blood-sucking but both males and females can live on
nectar if they can get nothing better. The larger horse-flies
belong to the genus Tabanus, which includes the less common
mourning horse-fly, Tabanus atratus. The smaller and more
common banded horse-flies of the genus Chrysops attack man
as well as animals. These have banded wings, brilliantly
colored eyes, and black, or brown and yellow bodies (Fig.

235).

Eggs. — Masses of their shining black eggs are laid in beauti-
ful symmetry upon the leaves of reeds a few inches above the
water (PL XVII).

Soldier-flies, Family Stratiomyiidae. — Adult stratiomyids
are flower insects which get their name, soldier-fly, from their
gay stripes. Alany of the larvse (Fig. 236) are not aquatic
but live in decayed material and under bark. Although they
are not abundant, the ones which do live in the water are
noticeable because of their peculiar appearance. They are

Fig. 236. — Larva of a soldier-fly.

spindle-shaped, stiffened, and dead-looking", with a circlet
of plume-like bristles surrounding the pair of spiracles open-
ing at the small end of the body, usually thrust through the
surface film for air. Above the surface film the bristles spread
out like a flower whose upper surface is completely dry. They
are carnivorous in their food habits. The pupa forms within
the larval skin. Length of larva, 1-2 inches.

Syrphus-flies, Family Syrphidae. — The adults (Fig. 237)
are flower flies which love sunshine and among them are some

299

A

FIELD BOOK OF PONDS AND STREAMS

Fig. 237. — I, Drone-fl}^ Eristalis tenax; 2, its
larva, the rat-tailed maggot, showing the tail-like
air-tube.

of the largest and brightest colored of all the Diptera. In
some species such as the drone-fly (Fig. 237) they look so
much like honey-bees that they are easily mistaken for them.
Larvae. — The larv^ae are found in all sorts of materials and
places, water, decaying wood, in fungi, and in the nests of
ants and bees. This larva of the drone-fly (Fig. 237) lives
in foul water where it feeds on decaying organic matter. It
was named "rat-tailed maggot" because of the long tail-
like air-tube which can be extended to the surface when the
larva is immersed in water or in decaying muck. This tele-
scopic tube is composed of two segments, one of which can
be slipped over the other; at its tip there is a rosette of hairs
which keep water out of the air-tube. The body of the
larva is about half an inch long. The larval skin contracts
to form the dark homy pupal case.

300

CHAPTER XVI

SNAILS AND MUSSELS

MoUusca

Clams and mussels, oysters, snails and slugs are all mol-
lusks; so are the less known chitons, the squids and the
octopus tribe of sea story fame. All these have soft unseg-
mented bodies, and shells either covering them over the out-
side as in clams, mussels and snails or concealed in a mantle
of flesh as in the squid and octopus. Counting those of land
and water, approximately fifty thousand species of moUusks
are known and one-fifth of them live in fresh water. All of
these fresh water inhabitants are either snails, the class
Gastropoda (stomach foot), or mussels and clams, the Pelecy-
poda ((hatchet foot).

Habits and dwelling-places. — Snails abound in shallow wa-
ters, one to six feet deep, where algse and water plants, their
main food supply, are also abundant. Snails and mussels to-
gether make up a very large part of pond and stream popula-
tions and are also plentiful in lakes and rivers (Figs. 21, 22).

In general, large mussels (Fig. 265) live ih large bodies of
water but there are many exceptions. One known as the
white heel-spitter, Lasmigona complanata, which is about four
inches long, is equally abundant in large and small streams.
Snails and the little mussels or "finger-nail " clams so plentiful
in brooks and small ponds are also found in rivers and lakes
sometimes at a relatively great depth.

Mussels live on the bottom, but snails migrate back and
forth from top to bottom. Snails are great travelers and there

301

FIELD BOOK OF PONDS AND STREAMS

is no level of the shore waters which is not accessible to them.
They trail over the bottoms and along shore, climb the plant
stems, glide over the underside of the surface film (Fig. 34)
and swing down through the water on mucous threads.
They carry a hea\y load of shell and they can only move slow-
ly, but they leave no crevice unvisited and have literally
taken possession of every level of ponds and the shore waters
of lakes.

In water deeper than six or eight feet the molluscan popu-
lation begins to fall off, the number of species becomes smaller
and where it is fifteen or twenty feet deep only a few kinds are
found. In his study of the mollusks of Lake Oneida, X. Y.,
Baker found forty-six species in one to three foot shallows,
forty species in water three to six feet deep, and only eleven
species at a fifteen to eighteen foot depth. Shallows are the
usual haunts of snails yet there are records of pioneers like
LymncEa (Fig. 245), Planorhis (Fig. 249), and Valvata (Fig.
257) which have been found in Lake Michigan at depths of
eighty feet.

Associates and enemies of mollusks. — 'Companies of small
snails and other animals seeking the same food can be found
beneath nearly every lily pad. Such gatherings usually
include a wheel-snail or two, Planorhis, a Physa, midge larvae
and bristle worms (Fig. 18).

In spite of their shells, snails and mussels are eaten by nearly
all kinds of animals larger than themselves. Several leeches
such as Glossiplionia complanata (Fig. 118) live exclusively on
snails and worms. Other animals, certain dragonfly nymphs
(Epicordtdia), giant water-bugs, fishes, frogs, salamanders,
turtles, and even muskrats, eat them along with other food.
Piles of mussel shells are commonly seen near muskrat holes
(Fig. 238). Muskrats carry the mussels out of the muddy
shoal water onto land, piling them up near rocks or logs.
There they soon die and their shells gape open, exposing their
soft bodies to easy access.

302

SNAILS AND MUSSELS

Fig. 238. — A Japanese student's sketch of a musk-
rat's pile of mussel shells. (Drawn by Fumiko
Mitani.)

In his study of the food of fishes in Lake Oneida, N. Y.,
Baker found that forty-six out of fifty-four species of fish ate
moUusks. The brook trout was one of only five kinds in
which mollusks made as little as one per cent of the whole
diet, on the other hand they made up twenty per cent of the
bullhead diet and ninety per cent of that for sturgeons.

Collecting, aquarium study. — A good way to learn something
about mollusk society is by taking a census of a square
foot or two of the pond or brook where they live. (Fig.
239.) If the other organisms which are present be included,
leeches, dragonfly and mayfly nymphs, aquatic plants, a fair
picture of the community will be secured. "^ Plants provide
food for mollusks, mayflies compete with them for the same
food, leeches are rank enemies and eat them. Such inter-
relations can be equally well studied in lily pad, algal mat
and pond weed communities. Mollusks of each kind and
sometimes other animals too should be preserved for identi-
fication and record (p. 40).

For aquarium study any pond snail is easy to keep, but
Physas (Fig. 248) are the most active. They will live com-

303

^

FIELD BOOK OF PONDS AND STREAMS

• .'..rlanortls'.

' "•J

>£;r-'V:^-''^i

'Plar;oVb^^^^->/^^:^"i^

:^--^

• '-<. ..'»,iv

i"'" /«ShL ■'•■ ^p*^ '"-^ rlai

^i^^^^^^-Coy-t^ule^abter

Fig. 239. — Diagram of one square foot of a pool
bottom, showing snails and mussels and associated
animals.

fortably with the simplest arrangements, a glass of water,
with a little fresh supply occasionally added, some scrapings
of algis, and branches of water plants (Fig. 34). For more
permanent living quarters the aquarium should contain four
to six quarts of water and have a layer of sand and pebbles
on the bottom in which a few branches of Myriopliylliim,
Nitella, Elodea, or other water weed have been planted. If
some algal scrappings be thrown into the water algag will grow
on the glass sides if the snails do not keep it too well cleaned.
Snails will live the year round in such an aquarium and will
lay their eggs on the glass sides, and the embryo snails can
be seen developing within their transparent jelly (Fig. 35).

Snails. — Gastropoda

Form and habits of water snails. — Snails are not only numer-
ous but conspicuous and familiar. Unlike mussels they travel
about in the upper levels of the water where they can be seen;

304

SNAILS AND MUSSELS

there their twisted shells attract attention and they are easily
remembered. A snail's shell is a spiral cone and beneath its
apex is the back or dorsal side of the animal. Most snail shells
are right-handed, some are left-handed. When a right-handed
shell is held with its opening toward the observ^er and its apex
up, the opening will be at the observer's right. Held in the
same position the shell of a left-handed snail will have its
opening at the left (Fig. 240).

^— 1

Fig. 240. — Diagrams of snail shells, showing
regions and types of twisting. A. — Right-handed
shell: I, apex; 2, spire; 3, body whorl; 4, columella;
5, opening or aperture; 6, lines of growth. B. —
Left-handed shell.

Shell is the hardened secretion of surface and border cells
of the fleshy mantle beneath it, and lines of growi;h show suc-
cessive additions of new shell. The shell is twisted on an axis
known as the columella (Fig. 240).

A' snail's body is coiled and twisted like the shell and ex-
tends into its apex. A fresh water snail has a distinct head
bearing two conspicuous tentacles with a small black eye at
the base of each (Fig. 241). Land snails which occasionally
wander down to the water margin can be distinguished by
their four tentacles. Snails have one to three chitinous jaws
in the upper part of the mouth and on the floor of it a ribbon-
like tongue or radula whose outer surface is covered with
rows of homy teeth (Fig. 241). This radula is their all-

305

FIELD BOOK OF PONDS AND STREAMS

important eating tool, a flexible file by which they rasp off
the cells of delicate plant stems and clean the alg^ from stones
and leaves. It is covered with small teeth and hooks, differ-
ently shaped and arranged in various species. The diversity
of the teeth in different kinds of snails forms the basis for a
large part of their classification.

attoLcheJ
to mouth

Fig. 241. — I, Diagram of snail; 2, jaws; 3, upper
surface of tongue or radula.

Snails glide slowly about on their one large muscular foot
over the bottom of which wave-like contractions of muscles
constantly pass from front to rear. These quickly succeeding
waves can be clearly seen on the feel; of snails as they move
over the sides of an aquarium or beneath the surface film of
water (Fig. 242).

Fig. 242. — Pond snail, showirig the under surface
of the foot against a glass and (dark bands) the suc-
ceeding waves of contraction in the muscles.

306

SNAILS AND MUSSELS

Among the aquatic snails, one group, the Streptoneura,
breathes by means of gills; another, the Pulmonata, by a
lung-sac. The gills of the streptoneurans lie in the space
between the body and the mantle through which water flows
freely. They have an abundant circulation of blood to which
oxygen is supplied by the water constantly flowing across the
gill. Gill-bearing snails have a homy plate or operculum
on the upper surface of the foot near the rear end (Fig. 243).
When such a snail draws into its shell, pulling its foot after
it, the operculum comes last and entirely fills the opening of
the shell, thus completely protecting the body. The small,
smooth opercula of marine snails, commonly knowm as "eye-
stones," were once much used to remove irritating substances
from the eyes. The "eyestone" was slipped under the eyelid
in order to increase the flow of the lachrymal fluid and thus
wash out the foreign particle. Different species of snails
have distinctive opercula. They are often found in the
stomachs of fishes and the kind of snail that was eaten can
be determined by them.

Fig. 243. — A gill-bearing snail showing the
operculum: i, snail extended, operculum on the
upper surface of the foot; 2, snail drawing into its
shell, pulling the operculum into the opening.
(After Baker.)

The lung-sac of the pulmonate snail is an air chamber en-
closed by a part of the mantle through which, as in the gill,
there is an abundant circulation of blood. A pulmonate

307

Jl

FIELD BOOK OF PONDS AND STREAMS

snail can take enough air into its lung to last it for a long time
under water. An occasional bubble can often be seen escap-
ing from lung-sacs of snails thus submerged.

In some snails the male and female sex organs are in dif-
ferent individuals ; others are hermaphrodites with complica-
ted male and female systems within the same animal. Usually
two animals mate together, whether hermaphrodites or not.
In the family Lymnmidm (Fig. 245) there are some evidences
of self fertilization. Alany snails lay eggs, depositing them
in masses of protecting jelly (Fig. 244), others, such as Cam-
peloma, are viviparous, bearing their young alive.

Fig. 244. — Cluster of eggs of pond snail, Physa,
showing the eggs within their capsules of jelly and
these embedded within the general mass.

Eggs. — Snails lay their eggs on any submerged objects, espec-
ially upon plants and protected regions of stones. The little
groups of them are embedded in drops of crystalline jelly.
There are never many eggs in a clutch, each one is surrounded
by its individual capsule of jelly and all the capsules are sur-
rounded by the general mass (Fig. 244). Developing snails
can be clearly seen through all the jelly; they turn over and
over within their capsules, and as they grow older their black
eyes and snail hum.p are clearly recognizable through a hand-
lens.

Pond snails, Family Lymnaeidae. — These are air-breathing
snails whose shells are thin, with a right-handed coil (Fig.
240), an acute spire and a large body aperture. The animal
has a short, rounded foot and flattened, triangular tentacles.
These snails live in lakes, ponds, swamps, and smaller streams

308

SNAILS AND MUSSELS

and are important in the diet of frogs, fishes, and wading
birds. The eggs are laid in an irregular slender oval mass of
jelly on stones and water plants.

Fig. 245. — Shell of pond snail, Lymncza palustris,
with body aperture shorter than the spire.

Lymnaea palustris. — The shell (Fig. 245) usually has 6
whorls, sometimes more; it varies from pale brown to black
and has a white thickening (callus) on the side of the opening
ne.xt to the axis. Length of shell, one and one-fifth inches.

Occurrence. — Widely distributed and in many places the
most common snail.

Fig. 246. — Shell of great pond snail, Lymncea
stagnalis, with long spire and flattened spire whorls. *

Great pond snail, Lymnaga stagnalis. — The shell (Fig. 246)
has 6 or 7 whorls, the lower ones very gradually increasing in
diameter so that a long slender spire is formed. Those in the
spire are markedly flat-sided. Length of shell, two and one-
half inches. The animal is horn-colored with a bluish tinge
on its short foot.

The great pond snail lives in the quietest parts of ponds and
slow streams foraging on Elodea, Myriophyihim, and other
water plants or on rotting vegetation. It often travels on
the underside of the surface film. Some varieties live on the
wave-beaten shores of lakes. It lays one hundred or more
eggs in a single clutch.

Occurrence. — In the northern states throughout the country.

309

FIELD BOOK OF PONDS AND STREAMS

"^ Fig. 247 — Shell of LymncBa columella, whose body
whorl is three times as large as its spire.

Lymnaea columella (Pseudosuccinea). — The shell (Fig. 247)
is greenish or yellowish, with 4 whorls the last of which forms
nearly the whole shell; the lines of growth are very heavy.
The body aperture is oval, expanded at the lower part.
Length of shell, three-quarters of an inch.

Occurrence. — Like L. stagnalis this species lives in quiet
water on lily pads, among cat -tails; it is rarely in running
water. Generally distributed throughout the United States.
Baker (Bibliography, p. 421) gives this species as Pseudosuc-
cinea columella.

Pouch-snails, tadpole snails, Family Physidae. — The shells
of Physidce are left-handed (Fig. 240), with a very large lower
coil, and the spires are sharp-pointed but short. The animal
has a narrow foot, pointed behind, and finger-like outgrowths
along the edge of its mantle which are very characteristic.
These are active snails which are extremely variable in color
and shape and ver>^ difficult to identify.

Occurrence. — ]Most of them are found in the United States
and Canada.

Fig. 248. — Tadpole snail, Physa gyrina {Phy sella) :
I, animal showing the slender pointed foot (after
Baker) ; 2, shell.

Tadpole snail, Physa gjrma. (Physella gyrina of Baker). —

The shell is thickened, heavy looking, with 5 or 6 coils. The
body aperture is loop-shaped, the outer lip, (Fig. 248) is apt

310

SNAILS AND MUSSELS

to be flattened and to join the body at a sharp angle. Length
one-half to three-quarters of an inch. Many references to
P. heterostropha apply to this snail (Baker, Bibliography,
p. 421).

Occurrence. — Common in eastern states.

Wheel-snails, Family Planorbidae. — These are air-breathing
snails without an operculum whose shells are twisted right
or left in a flattened coil, with the spire sunken in the center.

Fig. 249. — Three-coiled snail, Plajiorbis trivolvis:
I, animal expanded (after Baker); 2, -shell coils; 3,
shell showing body aperture.

Three-coiled snail, Planorbis trivolvis (Helisoma trivolvis
of Baker). — The shells are transversely lined and thin lipped.
Width of shell, about five-sixths of an inch. Typical trivolvis
lives in protected places, bays, pools, marshes, and swamps,
where the vrater is shallow. It is one of the larger wheel-
snails; this and its expanded bod}^ aperture (Fig. 249) help to
identify it.

311

A

FIELD BOOK OF PONDS AND STREAMS

Fig. 250. — TrivoJvis parvus: i, shell coils; 2, shell
showing body aperture.

Trivolvis parvus (Graulus parvus of Baker). — Its shell (Fig.
250) is small, only one-fifth of an inch wide, with 3 or 4 rapid-
ly enlarging coils. These very small wheel-snails are common
in mats of filamentous alg^ (p. 50), on pond weeds and
Myriophylliim, on most thick submerged vegetation.

Fig. 251. — Hairy wheel-snail, Planorhis liirsiitus:
I and 2, shell showing coils; 3, shell showing body
aperture.

Hairy wheel-snail, Planorbis hirsutus (Graulus hirsutus of

Baker).— These snails (Fig. 251) are found in still water of
ditches and swamps. They are sometimes distinctly recog-
nizable by the delicate hair-like projections of the outer shell
layer; these disappear when the outer layer is worn off. Shell
small, about one-fifth of an inch. Found in the eastern and
northern United States.

Fig. 252. — Limpet, Ancylus (Ferrissia of Baker);
underside of the animal showing its gill.

312

SNAILS AND MUSSELS

Fig. 253. — Fresh water limpet, Ancylus parallelus
(Ferrissia parallela of Baker): i, shell from above
showing the parallel sides; 2, the low cone in side

view.

oJpt-i-

Fig. 254. — Fresh water limpet, Ancylus rivularis
{Ferrissia rivularia of Baker): i, shell from above
showing the slight flare of the front end ; 2, side view-
Fresh water limpets, Family Ancylidae. — The shells are
small, about one-fifth of an inch long, shaped like a low cone.
The animal has short blunt tentacles and a very large oval
foot. It has a lung-sac like other air-breathing snails but
also has a cone-shaped gill or pseudobranch extending out
beyond the shell on the left side (Fig. 252). These snails live

Fig. 255. — I, Shell of Amnicola limosa; 2, animal
of Amnicola limosa porata, showing the truncated
foot and slender tentacles; 3, operculum of the
last variety, greatly enlarged (2, 3 after Baker).

313

FIELD BOOK OF PONDS AND STREAMS

in streams as well as in quiet ponds. They are common on
vegetation; Ancylus parallelus (Fig. 253) is often found on the
submerged stems of sedges in pond shallows, but A . rivularis
(Fig. 254) clings to stones in lively currents. Limpets are
generally distributed.

Family Amnicolidae. — These are small snails with shells not
more than half an inch long, and right-handed. The animal
has an oblong foot truncated in front and rounded behind (Fig.
255) ; its right gill is the only one developed. These snails
lay eggs, sometimes deposited on the shells of other snails in
clusters of eight or ten, as in the genus Biilimus, or singly as
in Amnicola. Snails of this family are common in shallow
water, on sandy bottoms, but also on pondweeds and other
vegetation. Widely distributed and common.

Fig. 256. — Shell of Goniobasis.

Fig. 257. — Valvata tricarinata: i, animal (after
Baker); 2 shell, showing keeled edge of whorls; 3,
shell, showing operculum in the body aperture and
cavity in the base of the spire; 4, shell from the side,
showing the blunt apex of the spire.

314

SNAILS AND MUSSELS

Family Pleuroceridae, Goniobasis. — These are gill-bearing
snails with an operculum. The shells have a long, conical,
right-handed spiral with 7 or more whorls (Fig. 256) ; full
grown ones are one and one quarter inches long. The
animals live in rapid currents, among water plants on lake
shores, in varied habitats.

Family Valvatidae. — These snails (Fig. 257) are small, with
shells not more than a quarter of an inch wide, with promin-
ent keels or ridges on the outer surface. The animals have a
short siphon which is two-lobed in front. The gills are
extended out of the shell when the snail is moving; the left
one is carried like a plume; the right is only a degenerate
finger-like process. Found in lakes in both shallow and deep
water. Widely distributed.

Fig. 258. — Vivipara contectoides, which has the
top-shaped shell characteristic of the family; shell
aperture filled by the concave operculum.

Family Viviparidae. — The shells of these gill-bearing snails
(Fig. 258) are globular or top-shaped, moderately large but
not more than two inches long. The young snails are bom
alive. The species Vivipara contectoides has four brown
bands on the body whorl. Found in lakes and rivers on
muddy bottoms.

Mussels. — Pelecypoda

Mussels are the only other fresh water mollusks besides the
snails. They are familiar either as rather large, dark-shelled
mussels which burrow in muddy bottoms or as "finger-nail

315

FIELD BOOK OF PONDS AND STREAMS

clams" lying upon the bottoms of clear pools and brooks. All
of them have two shells made by the hardened secretion of the

Fig. 259. — A. — A large mussel with its fleshy
foot pushed out into the mud. Arrows indicate
water passing in and out of the "neck" or siphon
(after Baker). B. — A "finger-nail clam" (Sphce-
ridcB), showing its delicate two-parted siphon
(modified after Baker).

fleshy mantle (Fig. 261) beneath, and all have a soft more or
less hatchet-shaped foot which has given them the name
Pelecypoda or hatchet-footed. At the rear end of the body
is the tube-like siphon (Fig. 259) through which water passes
in and out of the cavity within the folds of the mantle. In
salt water clams the siphon is called the "neck," as in "little
neck clams". Neither clams nor mussels have heads but their
mouths are located at the end opposite the siphon, recogniz-
able from the outside by the greater width of the shell.

Form and movements of the shell. — The two shells or valves
are joined by a spring-hinge at the back near the umbo (Fig.
260) and the closure is strengthened by hinge teeth. The
spring-hinge automatically opens the shells when they are
not pulled together by the animal. They are closed together
by means of two large adductor muscles whose opposite ends
are attached to opposing shells. Their attachment places
can be seen on the shell of any bivalve (Fig. 260). The
familiar "fried scallops" are the adductor muscles of the
scallop oysters. When a mussel relaxes its adductor muscles
they stretch and let the shells open automatically. This
occurs when a mussel extends its foot out between its shells

316

SNAILS AND MUSSELS

orilcrioT TcTrabTor

ant. odJucTor

^Traclo

usrko

knor re.1rt>£.1or of J«o1

muM.\« s>cc,r

t>allial Ivne uhert inan(l« mu&dei itnerled

FiC. 260. — Mussel shell: i, the outer surface,
showing lines of growth; 2, the inner surface, with
scars made by the attachment of muscle.

(Fig. 259) or lies at rest on the bottom with its shells partly
open. When they gape wide apart, the mussel is usually
dead.

Growth of the sheU. — The shell is produced by the outer
surface and border of the mantle. Additions are built on at
the edge and there the shell is newest and thinnest. In the
larger mussels there is a dark horny covering or periostracum
on the outside, then a thick limy layer, and finally the pearly
lining. The outer surface of the shell is marked by lines or
rings (Fig. 260), usually more conspicuous than the similar
ones on snail shells. These heavy lines or ridges seem to
indicate periods when cold or lack of food or some other cause
lowered the activity of the animal and kept it from secreting
very much new shell. They signify slow shell growth and the
spaces betv/een them mark periods of rapid shell growth.
Both hard and easy times in the mussel's life are recorded by
these lines of growth.

Form of the body. — These headless mussels rely entirely
upon currents of water to bring them food and oxygen. Such
currents are created by the movements of microscopic cilia
borne upon the mantle and body surfaces. By their motion
water is brought into the incurrent siphon, and distributed
through the gills and toward tha mouth, carrying minute food

317

FIELD BOOK OF PONDS AND STREAMS

Fig. 261. — A mussel, with the shell and mantle
of its left side removed to show the body lying with-
in the mantle cavity: i, mantle flap of right side; 2,
foot; 3, gills of left side; 4., triangular lip hiding the
mouth; 5, anterior and 6, posterior adductor mus-
cles; 7, incurrent and 8, excurrent siphons which
have been cut open; 9, cut edge of mantle of left
side.

particles with it. The foot is the fleshy process by which
mussels plough their way through the mud. Mussels are
often said to "lie on the bottom with their tongues out".
These "tongues" are their feet. The mussel's whole body,
gills, foot, and other organs lie within the mantle cavity.

\arooa ^>oucn

Fig. 262. — I, A female mussel, with the left
valve of shell and mantle removed to show the
brood pouch; 2, a larval mussal or glochidium much
enlarged.

Eggs and young. — The small mussels (SphcBridce) are her-
maphrodites but in the large ones eggs are produced by one in-

318

SNAILS AND MUSSELS

dividual and the sperm cells by another. Eggs pass from the
ovary into the mantle cavity and thence into the gills of the
parent mussel. Each gill is a flattened sac, partitioned off
into water tubes, and currents of water carry the eggs into
their open tops. Sperm cells are discharged into the water
by a male which is usually nearby. They are carried through
the incurrent siphon and finall>' into the gill of the female
where fertilization of the eggs takes place. Thus the thin
curtain-like gill becomes the brood pouch (Fig. 262) and each
water tube is filled with eggs like peas packed in a pod.
There the developing embryos remain until they have be-
come glochidia, larval mussels with their first juvenile shells.

A brood pouch is brown or whitish according to the color
of the eggs or embryos contained in it and so full that the
slightest tear in it will bring them streaming out like sand.
The number of embryos in the pouches varies with the species;
according to counts and computations there may be from
seventy-five thousand to three millions of them to a parent.
In the little glochidia the shells gape wide open/ but are
snapped together intermittently by the single add'uctor
muscle. If a few glochidia are put in a drop of water on a
piece of glass their convulsive snapping can be seen easily
with a hand-lens. The least jar in the water will start them
clapping almost in unison and if a drop of fish blood or a little
salt is dropped into the water there will be the wildest excite-
ment.

Their persistent snapping stands the glochiciia in good stead
when they are thrown out of the brood pouch. Then their

^ Fig. 263. — Minnow with larval musses or glochid-
ia clinging to its fins and body, taken from a brook
in midwinter.

3M9

FIELD BOOK OF PONDS AND STREAMS

only chance for life is in clamping their shells into the bodies,
gills, and fins of fishes (Fig. 263). They become imbedded
in the flesh, the skin grows over them, and they are protected
and nourished by the fish, being carried as actual parasites
for several weeks.

The glochidia of one species of mussel will usually stay only
on certain species of fish and if they get onto the wrong one
they will drop off. This seems to be a proof of their extreme
sensitivity like that shown in their behavior toward fish blood.

Pearly mussels, Family Unionidae. — These are large mussels
usually three or four inches long. Their shells are covered
with a dark colored horny periostracum and the inside is
pearly. The outer gill is used as a brood pouch. They are
abundant in the larger lakes and streams but are by no means
confined to them.

This family includes all of the large mussels except a few
now grouped in the MargaritanidcB. The family Unionidce
has been split up into subfamilies containing many genera.
Representatives of only two genera are mentioned here. A
detailed treatment of the mussels will be found in Ward and
Whipple's "Fresh-Water Biology" and Baker's "Fresh
Water Mollusca of Wisconsin."

Fig. 264. — Right side of Elliptio complanatus.

Elliptic complanatus (formerly Unio complanatus). — The

shells (Fig. 264) are thick, and oval or elongate, with smooth
or slightly corrugated surfaces. Their linings are nearly
always purplish and coppery. The breeding season is from
the last of April to the middle of May; the shells of the
glochidia are without hooks.

320

SNAILS AND MUSSELS

Found in creeks and small rivers on muddy bottoms in
shallow water, sometimes in sand. A common mussel on the
Atlantic slope to Georgia.

Fig. 265. — Paper-shell mussel, Anodonta cataracta:
I, left valve; 2, shell, showing beaks and hinge.

Paper-shells, Anodonta. — The shells are thin, generally
smooth and shining, often winged posteriorly (Fig. 265). • The
outer surface is greenish or brown and is often marked by light
and dark concentric bands indicating rest periods in growth
(P- 317); the lining is dull white or pinkish. The breeding
season is in late summer. When full the brood pouch of the
outer gill looks like a thick brown pad. The glochidia can
be found in the pouches through October and often into mid-
winter; each shell bears a hook. Length of adult about 4
inches.

Found in clear running streams, also in lakes. Common on
the Atlantic slope, south to South Carolina.

Finger-nail clams, Family Sphaeridae. — Few of these small
white mussels or "finger-nail clams" are more than half an
inch long; SphcBrium sulcahun (Fig. 266), one of the largest of
the family, measures three-quarters. The shells are thin,
usually white, or yellowish, and the lining is dull white. The
form of the animals is similar to that of the larger mussels but

321

FIELD BOOK OF PONDS AND STREAMS

the brood pouch is formed by the inner gill and the number
of young is comparatively small, from two to twenty varying
with the species. The breeding season seems to continue
more or less through the year.

Members of this family live in lakes and rivers as well as
in ponds and pools and small streams (Fig. 22). They live
on bottoms of sand and mud or clay and often creep up over
plant stems. They are widely distributed, almost sure to be
found in any kind of fresh water. Species are numerous and
difficult to distinguish.

Pig. 266. — Sphere-shells, Sphcerium: i,S. sulcatum,
left valve, showing small hinge teeth {h)\ 2, same
shell with centrally placed beaks (a) ; 3, animal of
S. striatum, showing divided siphon (after Baker).

Sphere-shells, Sphaerlum. — Mussels of this genus have oval
shells and centrally placed beaks (Fig. 266) ; the hinge teeth
are very small. The incun-ent and excurrent siphons are
separate except at the base. The unusually large species S.
sulcatum is often found in moderately swift streams. East
of the Rocky Mountains.

Fig. 267. — Shell of Musculium showing the cap-
like beaks: I, left valve; 2. inner surface of right
valve, hinge teeth hardly developed (a) ; 3, shell with
cap-like beaks.

322

SNAILS AND MUSSELS

Musculium. — The shells of Musculium are thinner than
those of SphcBrium; the hinge teeth are small, almost missing,
and in nearly all of the species the beaks are cap-like (Fig. 267).
The siphons are longer than those of SphcBrium and are at-
tached to each other throughout their length. Length of the
shells, three-eighths of an inch. Musculium and SphcBrium
live in the same kind of haunts.

Fig. 268. — Pill clam, Pisidium: i, P. virginicum,
right valve, note the long anterior end; 2, same, left
valve from within, showing cardinal teeth (a) ; 3,
same, shell showing beaks (6) located posterior to the
center; 4, animal of P. pohtum decorum, showing
the single siphon (after Baker) .

Pill-clams, Pisidium. — The valves of the shell are slightly
unequal in size; there is one cardinal tooth in the right and
two in the left valve (Fig. 26S). The foot is tongue-shaped
and large for the size of the animal. The siphon is short and
only the excurrent part is present; water enters the mantle
cavity through a cleft in the mantle. Like the other small
mussels the members of this genus live in varied habitats.
They not only burrow in mud but they crawl up on plants;
Elodea, Potamogetons, and floating algae frequently hold many
of them. Pisidium virginicum is recognizable by its size,
unusually large for Pisidium, its oblique shell and peculiar
cardinal teeth. Length of shells, one-quarter to three-eighths
of an inch.

323

CHAPTER XVII
LAMPREYS AND FISHES

Fishes belong in the water and nowhere else ; there they find
their food and produce their young. Frogs shed their eggs
in the water but range over the land for something to eat;
pond turtles forage through the shallow waters but deposit
their eggs on land. Water birds go to it only for food and
safety but never lay their eggs in it. No mammal, not even
a whale, can stay under water indefinitely, and the life of
aquatic mammals like muskrats and beavers is one of constant
come and go from water to land. But fishes are ever-present
in water society — the only group of vertebrates which can
survive a constant water environment.

Fishes have taken possession of the streams and lakes as
well as the sea. They are surface skimmers and bottom feed-
ers, dwellers in rapids and in still coves; they are big and little,
long and slender or short and thick, drab gray or silver and
gold colored, metallic blue and green.

Structure of fishes. — All are vertebrates. They breathe
by means of gills; they all have fins, and they are usually
covered with scales. Most of them lay eggs which are ferti-
lized in the open water as soon as they are laid, but some
give birth to living young. The eggs of most marine fishes
float upon the surface, but those of fresh water fishes lie loosely
on the bottom or are stuck fast to stones. All fish eggs are
well stocked with yolk, and the young fish carry a yolk-sac
about with them for several days after they hatch and are
thus well provided with food wherever they go.

324

LAMPREYS AND FISHES

Fig. 269. — Diagram of a fish: i, mandible; 2, pre-
maxillary; 3, nostrils; 4, opercle or gill cover; 5,
pectoral fin; 6, dorsal fin; 7, ventral or pelvic fin; 8,
anal fin; 9, caudal fin; lo, lateral line of sense organs;
II, scales.

The fins of fishes are thin membranes supported by stiff
spines or by finely segmented rods, the fin rays, which are
often branched (Fig. 269). Fins are very constant in num-
ber and position. Just back of the head are the paired pector-
al fins, and further backward, low down on the sides of the
body, are the paired pelvic or ventral fins ; others — the dorsal,
anal, and caudal fins — are single.

The opercle forms part of a fish's cheek and covers the four
blood-filled gills, that are often visible when it is lifted in
breathing. The jawbones, mandible and movable premaxil-
lar^'-, usually bear sharp teeth, and besides these, fishes have
several patches of short teeth on the roof of the mouth.

Breeding habits. — As the spawning season approaches,
fishes move toward the shores of ponds andlakes or upstream
in the creeks. Some of them, such as perch and sunfish, only
swim in among nearby weeds or protecting stones. The
journeys vary from such short ones to the famous migrations
of river salmon, extending over hundreds of miles ; but they all
end at spawning grounds or nesting sites. During this time
color differences between male and female appear or become
more marked. Fins of the male darters redden, the colors
of male sunfish (PL XVIII) take on the brilliance of a hum-

325 .

FIELD BOOK OF PONDS AND STREAMS

mingbird, and pearl organs appear on the head of the blunt-
nosed minnow (p. 336).

During the breeding season the male and female usually
stay close together and the male discharges sperm cells over
the eggs the instant they are scattered into the water. Often
at this time both fishes take a very definite position. The
female rainbow darter half buries herself in the bottom gravel
and lays a few eggs at a time, the male shedding sperm cells
over them as soon as they appear. Many fishes build nests,
sometimes elaborate and constructed by both parents, some-
times only by the male, as in the brook stickleback (p. 339),
which fashions its nest and then swims forth to coerce a mate
into it.

The eggs may be guarded and cared for, the male often
taking the greater if not the sole responsibility for them.
Among the yellow catfishes both parents keep the eggs clean
by stirring and fanning them with their fins; occasionally they
take a few into their mouths, then spit them out again, repeat-
ing the performance over and over. After hatching, they
tend the young fry even more thoroughly and turn them over
and about, using their barbels (Fig. 278) for stirring rods.

Aquarium study. — Several of the fishes later mentioned live
well in aquaria, but whatever their kind, they must be small,
unless the aquarium is a very large one. A fish about one
inch long should be given a gallon of water, and water should
always be allowed in proportion to the size and number of
fishes. They should have plenty of water plants (p. 39)
about them and a small supply of food. Natural food is the
best for them, is healthier and far more interesting than pre-
pared fish foods. The best natural fish foods are small crus-
taceans like Daphnia and Cyclops, midge larvae, and other
small insects, especially the nymphs of quiet water mayflies.

In selecting the fishes it is important to choose those which
will live peaceably together. Different kinds of minnows
will do this, but sunfishes, catfishes, and sticklebacks will not.

326

LAMPREYS AND FISHES

A pair of the hardier sticklebacks (p. 339) will sometimes
nest and carry on all their egglaying activities in a comfort-
able aquarium supplied with their building materials.

Fall is the best time to collect fishes for aquaria. They
are in good condition then and during the cool weather it is
easier for them to get used to the close aquarium. When
they are newly captured they are liable to jump out of the
water; they are safer if the aquarium is kept covered with a
screen. If an aquarium is properly balanced the water will
not need changing (p. 39) ; and if cleaning becomes necessary,
it is better to pour the old water out, strain it, aerate it by
pouring it through the air, and then use it again. Fishes get
on best in the old water to which they have grown accustomed.

There are several good books on aquarium making; soma
of these are listed in the Bibliography (p. 409).

Common brook and pond fishes. — A few families of ponJ
and small-stream fishes are briefly discussed here. These are
selected because they are common, or easy to observe, or both.
Keys and more particular descriptions can be found in. Jor-
dan's "Manual of the Vertebrates" and other books named
in the Bibliography (p. 421).

Fig. 270. — Lake lamprey, Petromyzon mariniis,
attached to a fish. Above the pectoral and ventral
fins are scars showing where other lampreys made
ragged openings with their rasping tongues. (Pen
drawing by S. H. Gage.)

Lampreys. — PetromyzonidcB

Lake lamprey, Petromyzon marinus. — ^Lampreys are neither
eels nor true fishes although they resemble both. Almost

327

FIELD BOOK OF PONDS AND STREAMS

every feature of a lamprey is peculiar. Its most striking one
is the large suction disk which surrounds the mouth, bearing
circlets of horny teeth upon its surface. The adult lamprey
fastens this armored oral disk to the side of a fish, rasps its
teeth into the flesh and sucks out the blood, and the fish
carries it about as long as it is able to swim (Fig. 270).

Most species of lampreys pass part of their lives in salt
water but several kinds live entirely in fresh water and all of
them lay their eggs there. The lake lamprey or lamprey eel,
Petromyzon marinus, is one of those which lives in fresh water.
It is a land-locked form, generally considered the same species
as the great sea lamprey. Lampreys are abundant in the
Finger Lakes and tributary streams and in Oneida Lake alone
it is estimated that tons of fish are killed by them every year.
In spring these lampreys leave the lakes and migrate up the
creeks. They rest by night but travel by day until they final-
ly reach the riffly shallows where they make their nests.
There the male lamprey or a pair working together clears a sort
of shallow basin on the bottom, moving pebbles away from a
middle space and piling them in a low circular wall surround-
ing it. They pick up the stones with their oral disks, some-
times actually carrying them a foot or more.

After the nest is completed the lampreys mate. They
cling to its upstream wall as if resting, but their rest is brief.
Using his oral sucker the male grasps the female behind her
head, twines his tail tightly against her sides, and for a short
period, generally only a few seconds, the two lampreys shake
and twist their bodies in great excitement. During this time
the eggs are laid and almost immediately buried beneath the
sand which is whirled over them by the struggling lampreys.
By the time the mating excitement is over the eggs are mostly
covered but as soon as they separate the two lampreys move
more sand and pebbles over them. They fan the sand with
their tails, the females having an extra growth of nn (anal)
at this time of year. They work at this for a few minutes,

328

LAMPREYS AND FISHES

and then mate again. At each mating the female lays 20 to
40 eggs, and matings are kept up at intervals for 2 to 4 days
until 25,000 or 35,000 eggs are laid. In streams which
flow into Cayuga Lake the lamprey spawning season lasts
through April, May and June. The worm-like eyeless and
toothless larvae stay in the nest for a few weeks after hatching,
and then burrow into the sand, living like worms in the stream
banks until they are about five inches long, when they trans-
form to the adult shape. Adult lampreys live wholly upon
fish blood except during their actual breeding season. They
are ravenous for a long time before this and kill hundreds of
fish, which appear floating upon the surface with large holes
bored through their sides. The upturned body of a dead fish
with its quota of lamprey holes is a familiar sight in more
than one of the New York Finger Lakes.

Size. — Length of adults 2 to 3 feet.

Distribution. — Lampreys which live entirely in fresh water
are found in the Great Lakes and their tributaries and in
some streams in New England and the middle Atlantic states.
Along the Atlantic coast large sea lampreys go up the streams
to spawn. They are found in the Merrimac River, the Con-
necticut, the Delaware, and some of the streams of Long
Island.

Fig. 271. — Brook trout, Salvelinus fontinalis.

329

FIELD BOOK OF PONDS AND STREAMS
Trout — SalmonidcB

Brook trout, Salvelinus fontinalis. — Brook trout are the
choicest of the famous salmon family, the symbol of high
spirited gaminess in fish life. In America several kinds of
fishes are called trout and the word does not connote the wild
grace and delicacy which especially belong to real trout.
But the English keep the special name "charr" for this
branch of the salmon family. Other members of this genus
are the Rangeley Lake trout {Salvelinus oquassa), and the
"Dolly Varden" trout or salmon {Salvelinus malma) which
lives in streams west of the Rocky Mountains. These and
other trout in the genus Salvelinus are brown or olive colored,
spotted with gray or scarlet, and their fins are tinged with
bright colors. Their scales are small and well hidden in the
skin.

The brook trout, Salvelinus fontinalis (Fig. 271), is covered
with red spots on a mottled black and olive background which
fades almost to white upon the ventral side. It is heavier
headed than other "charrs," rather large mouthed, and
though it varies in size with its living place, it seldom weighs
more than seven pounds and is usually smaller. Brook trout
can live only in clear cold water, but it does not matter whether
they are in ponds or brooks, or rivers, and they will even
migrate back and forth to the sea when that is easily accessible.
But in nearly all their haunts they are each year becoming
more scarce because of overfishing, pollution of water, and the
varied uses which humanity has made of their native streams.
For most persons, even many sportsmen, the place of the
wild trout is being filled by fattened trout reared in private

ponds.

Brook trout spawn from early fall to late November.

Size. — Many adults of spawning age measure but 6 inches
while others are 10 to 12 inches long and may weigh several
pounds.

330

'S

LAMPREYS AND FISHES

Distribution, — Only east of the Mississippi and Saskatche-
wan Rivers ; from northern Georgia to Labrador and Hudson
Bay.

Fig. 2^2. — American eel, Anguilla hostoniensis.

Eels — A nguillidcB

American eel, Anguilla bostoniensis. — Fresh water eels
(Fig. 272) are snake-like fishes which live in fresh water from
their early youth to breeding time and then migrate into salt
water, probably never to return again. The eels which come
up the streams are the young ones of another generation which
have traveled the long and unknown way from the sea.

Fullgrown eels are about three feet long, plain colored,
greenish brown above and pale greenish gray beneath. Every
inch of their bodies is sinuous and flexible, well earning the
phrase "squirms like an eel."

During their fresh water sojourn eels usually live on the
muddy bottoms of streams or in stream-fed ponds. Although
they generally seek deep streams they often work their way
up brooks along the coast. It is a surprising but not a unique
experience to catch an eel on the hook which is meant for a
brook trout. Sometimes eels come out of the water and hide
under stones in swampy ground a few feet from the shores and

331

FIELD BOOK OF PONDS AND STREAMS

they have been seen foraging on the sand along stream sides.

Eels eat almost any animals dead or alive — insects, fishes,
frogs, water-rats — as well as aquatic plants.

The life history of eels was not completely known until
1925 when Schmidt published his studies of both American
and European species. The breeding place of American eels
appears to be north of the West Indies, west and south of
regions where European eels breed. Eels spawn in these
deep waters and the eggs hatch into transparent floating
larvae. American eels keep their larval form for about a year
during which they drift near the surface. Then they are
caught in the current of the Gulf Stream and carried toward
the American coasts. Only when they near the coastal
waters, at a depth of 3000 feet or less, do they begin to take
on the shape of adult eels. Finally small eels but 2 or 3
inches long begin to come up the rivers in great numbers.
In Rhode Island young eels go up the Taunton River through
April and May; in some other rivers they appear later; in
many of them, thousands can be seen on the mud flats at river
mouths when the tide is out. Like lampreys they rest by
day and travel by night, with unbroken persistence working
their way up toward the regions forsaken by their parents.
Only the females persevere to the head waters; the males
stay in the lower parts of the stream. They live in these
places for 6 or 8 years and then another change comes
over them. They cease eating, their skins turn white and
shimmering and they begin their long journey to the sea.
These are the "silver eels" which are caught in traps, as they
journey downstream, resting by day and moving by night as
they did when they traveled upstream 6 or 8 years before.

Size. — Fullgrown, 3 to 4 feet long.

Suckers — Catostomidce

Common sucker, mullet, Catostomus commersonii. — Com-
mon or white suckers are easily recognized by the rounded

332

LAMPREYS AND FISHES

Fig, 2-]}^. — Common sucker, Catostomus cotnmersonii.

sucking mouths (Fig. 273) located well under the head, not at
the end of it as in most fishes, and by their thick fleshy lips.
Fullgrown suckers may be a foot long, but in small streams
they tend to be much shorter.

In early spring soon after the ice breaks, suckers usually
swim upstream into the shallows to lay their eggs, but this
does not appear to be a universal habit, for some spawn in
ponds. By late July the younger fish are nearly an inch long,
and at this stage they have terminal mouths instead of suck-
ing ones like their parents. Although suckers are usually
a nondescript olive, during the breeding season the fins of the
male become tinged with rose color. One female spawns with
two males, one of them crowding against each side of her,
discharging their milky sperm fluid (milt) as soon as any eggs
leave her body.

Suckers are bottom feeders on mud rich in diatoms, midges,
worms, and mollusks. They are used, to some extent, for
food, and those of Lake Erie are of considerable commercial
importance.

Size. — Up to 18 inches, or more, but this is unusually large
especially for small streams.

Distrihutinn. — Abundant in almost every small stream and
pond east of the Rocky Mountains.

333

FIELD BOOK OF PONDS AND STREAMS

Minnows and Carps — CyprinidcB

The minnow family, CyprinidcB, contains over a thousand
species of North American fresh water fishes, many of which
are difficult to distinguish from each other. Familiar mem-
bers of the family are the large German carp or lake trout of
the markets, gold fish, and such small fishes as the dace, chub
and brook minnows.

Fig.
nasus.

274. — Black-nosed dace, Rhinicthys atro-

Black-nosed dace, Rhinicthys atronasus. — This is a little
minnow (Fig. 274) usually less than three inches long, which
can be caught by shuffling the stones and gravel of brook beds,
at the same time holding the net on the downstream side of
them (p. 34). During the fall and winter months they are
almost sure to be carrying young mussels on their fins (p. 319).

The "black-nose" is marked by a broad black band which
runs along each side of its bo^y from the tip of the nose back
to the tail, separating the olive green of the back from the
silver}'" white of the underside. The short underjaw makes
its head look blunt.

Black-nosed dace avoid the wide creeks and live in little
streams where there are rapids and clear pools. They are
nearly always found in trout streams and brook trout are
known to eat the young ones. The}^ breed in spring and early
summer. Then the male's fins are tinged with red and the
long black stripe is bordered with bronze. Although they

334

LAMPREYS AND FISHES

are common fishes very little has been written about their
spawning habits.

Size. — 3 inches.

Distrihutio7i. — New England to Minnesota, southward to
Oklahoma; very common.

Fig, 275. — Common shiner, Notropis cornutus.

Common shiner, redfin, Notropis cornutus. — Shiners (Fig.
275) are abundant in most brooks and creeks whether they
are warm ones or cold. Several of the silvery hued minnows
are called shiners but the true one is the common shiner or
redfin, known as the shiner to fishermen, who use it for black
bass bait. It is about five inches long and has a deep, com-
pressed body whose sides are covered by diamond-shaped
scales. Its back is olive green, the rest of the body silvery
white. In the breeding season the fins of the male are bordered
with red, its back is iridescent blue, and its sides are rainbow
hued. At this time little horny cones appear on its head,
giving it the names "horny head" and buck fish.

Redfins spawn during May and June. A single pair or
often a small school of a single male and several females
assemble in a riffle 6 to 8 inches deep. The nest is a basin-
shaped clearing in the gravelly bottom, about a foot in diame-
ter and a couple of inches deep. According to one observation
of Dr. G. C. Embody, just as soon as the eggs were dropped
to the bottom they were sought as food by other dace, which
wedged their bodies in between stones in pursuit of them.

Size. — Up to 8 inches.

n "^ C

FIELD BOOK OF PONDS AND STREAMS

Distribution. — East of the Rockies except Texas; very
common.

^

tus.

Fig. 276. — Horned dace, Semotilus atromaciila-

Homed dace, chub, Semotilus atromaculatus. — Homed
dace (Fig. 276) are stream fishes often found with the black-
nosed dace. They are dusky bluish in color with a conspicu-
ous black spot at the base of the dorsal fin, which is bordered
with red in the male. During the breeding season through
May and July the heads of the males are orange colored and
are covered with little hornlike growths or "pearl organs,"
which have given them the name of horned dace.

The male builds the nest in the riffles. It is a shallow pit
walled with small stones which he pushes into position with
his head. Females enter the nesting basin, lay a few eggs
and leave it, but the male remains to guard them.

Size. — 10 inches.

Distribution. — Maine to Wyoming, south to Alabama;
common.

Fig. ijj. — Blunt-nosed minnow, Hyborhynchus
not at us.

Blunt-nosed minnow, Hyborhynchus notatus. — The blunt-
nosed minnows (Fig. 277) are never more than four inches

336

LAMPREYS AND FISHES

long, olive colored, bluish on the sides lighted with dull silver,
and have a black spot at the base of the dorsal fin and another
at the base of the caudal fin. They frequent small streams,
either muddy shoals or gravelly bottoms, and they breed in
quiet water, two feet or so deep. The eggs have been found
glued on to the undersides of stones or boards and closely
guarded by the males. The breeding season extends through
late May to mid-July.

Other names for this minnow are spotted minnow, flat-
head, and chub.

Size. — 4 inches.

Distribution. — Quebec to Dakota, southward to Alabama;
very common in small streams of the Alleghanies.

Fig. 278. — Common bullhead, Ameirus nehulosus.

Catfishes — Siluridce

Bullheads and Catfishes. — The barbels or "whiskers" of the
many species of bullheads and catfishes easily distinguish
them from all other fresh water fishes. They are smooth
skinned, flat headed, large mouthed, and dull colored fishes
which have a knoblike, fleshy fin behind the dorsal fin. The
common names, bullheads and catfishes, are used interchange-
ably. The name stonecat is used for the members of this
family which can sting by means of the spine on the front
edge of the pectoral fin and its associated poison gland.

There are few ponds and creeks without bullheads or cat-
fishes in them. The common bullhead or homed pout, Uving

337

FIELD BOOK OF PONDS AND STREAMS

in ponds and sluggish streams, is the commonest of the smaller
catfishes (Fig, 278). It is dark yellowish brown above,
var^ang to black, mottled on its sides and lighter beneath.
The black bullhead (A. melos) is very similar but small —
not more than 6 inches long — and almost black.

Most of the stonecats, Schilbeodes, live among the stones in
the riffles of rapid streams, skulking under the stones and
feeding upon insects, entomostracans, minnows, sometimes
crayfish. Their opaque yellow eggs are fastened to the under
sides of stones, in masses about two inches across and an inch
thick ; they spawn in June and July. Other names for fishes
of this family are common bullhead, homed pout, stonecat,
mongrel bullhead, deepwater bullhead.

Size. — Common bullhead, up to 18 inches; black bullhead,
10 inches; stonecat, 12 inches.

Distribution. — Common bullhead, IMaine to North Dakota;
south to Florida; introduced into California; very common.
Black bullhead, northern New York to Nebraska; southward
to Kentucky; common, especially westward. Stonecats,
Great Lakes region and westward to Montana ; south to Texas ;
common.

Fig. 279. — Common pickerel, Esox niger.

Pickerels — EsocidcB

Common or chain pickerel, Esox niger. — Pickerel live in
sluggish streams and in large ponds and lakes, where they
lurk among the weeds and beneath the lily pads. They have
slender bodies, long fiat heads, and projecting underjaws which
contribute to their sullen watchful expression (Fig. 279).

338

LAMPREYS AND FISHES

Like their relatives, the common pickerels hang stately and
quiet in the shadows of floating leaves, painted into the back-
ground by the olive brown and olive green network which
covers all but the pale undersides of their bodies. Now and
then they dart forth as swift as arrows, and clutching a hap-
less fish or a frog, take it down at a gulp and resume their
motionless watch.

Size. — Up to 24 inches.

Distribution. — Maine to Florida, west to Arkansas; com-
mon.

Sticklebacks — Gasterosteidce

The stickleback family is a tribe of fishes between two and
three inches long which have a row of sharp upstanding spines
on their backs. They live among the weeds of small streams
and are famous both for their pugnacity, and their industry in
nest-building. The sticklebacks are generally greedy and
quarrelsome; they will attack others, eat their eggs, and keep
themselves generally busy with other fishes' affairs.

Brook stickleback, Eucalia inconstans. — The brook stickle-
back has four free spines and a fifth spine which is attached to
the dorsal fin and is marked with indistinct dark bars across
its back (PL XVIII). In spring the male's back is almost
black, lightening to yellow beneath; at the same time the
female is olive colored, mottled and dotted with brown.

The nests of sticklebacks look like birds' nests and like
them are made of plant stems, but these nests are stuck to-
gether by a fluid from the kidneys of the male; the females
take no responsibility in its building.

Each nest is a delicate sphere about three-quarters of an
inch in diameter, with a hole on one side. It is made of fine
fibres, plant stems, and filaments of algse and attached to a
plant stem or a submerged twig. Against a background of
leaves and plant stems these little nests are well nigh undis-
coverable except by a chance happening. The male stickle-

339

PI. XVIII. — I, Brook stickleback, Eucalia inconstans; its
nest is made of algae and plant stems; 2, common sunfish,
Eupomotis gibbosus: its nest is a basin-like clearing on the
pond bottom.

■ i

k

PLATE XVIII

^»%*'*"^ •!

4^.

iv^mfi.dmiims^'^X'SS.-

LAMPREYS AND FISHES

back selects the nest site, bites off the plant stems, smears
them over with his mucous cement, smooths the walls by re-
peatedly pushing his head and body against them and finally
swims outside for a mate and drives her into the finished nest.
She stays inside the nest a little time, laying the eggs, and he
keeps guard, swimming round and round it. She swims out
as soon as she has laid the eggs, and he immediately enters
the nest to pour the sperm cells over them. This performance
may be repeated several times in quick succession by the same
male and different females.

Sticklebacks can be kept in a balanced aquarium and if they
are supplied with proper material the males of breeding pairs
will build their nests just as in the open.

Size. — Length up to 2 and ^ inches.

Distribution. — New York to Kansas and northward; com-
mon.

Sunfishes and Bass — Centrachidce

Sunfish, "pumpkin seed,-' Eupomotis gibbosus. — The sun-
fishes and their relatives, the rock bass and the black bass,
are all food fishes, beautiful and gamey, too. Probably best
known of all of them is the common sunfish or pimipkin seed,
of less economic importance because of its small size, but
greatly treasured as countless strings of "pumpkin seeds'*
could testify.

"Pumpkin seeds" are shaped like their namesakes. When
they are seen from above or in the pond bank shadows they
are drab olive colored, but as soon as they move into the sun-
shine their sides are rich iridescent blue and green flecked
with orange and dimly barred with olive. Near the edge of
the gill cover is one bright scarlet spot (PI. XVIII). The males
are brighter colored than the females and they have black
ventral fins while those of the females are yellowish. In the
males the dorsal and caudal fins are more brilliant blue.

Sunfish nests are basin-like clearings on the pond bottom

341

FIELD BOOK OF PONDS AND STREAMS

over which the male keeps close guard. In late May and
June he cleans a space on the bottom, about a foot across and
several inches deep, fanning gravel away with his tail and
pulling heavier stones with his mouth. Then he brings a
female to the nest and the two swim round and round with
their ventral sides close together while eggs and clouds of
sperm cells are discharged into the water. Soon after this
she departs, leaving him to guard the eggs, which become at-
tached to the small stones and gravel of the nest bed.

Size. — 8 inches.

Distribution. — Very common, especially in ponds; Maine
to Minnesota, southward to Florida, but less abundant there.

Fig. 280. — Small-mouthed black bass, Microp-
terus dolomieu.

Small-mouthed black bass, Micropterus dolomieu. — Fa-
mous as sportsmen's fish, both the small- and large-mouthed
black bass are well known and widely distributed in clear,
cool waters, streams and stream-fed ponds with rocky bottoms.
They thrive where crayfishes are abundant, these being the
favorite food of the adults.

Neither of the black basses is black. The small-mouthed
species is silvery to golden green with indistinct darker cross
bands; the large-mouthed black bass is green, darkly mottled
on the back and along a line on each side. But both vary
greatly in color and can only be distinguished by structure.
The small-mouthed bass has only a moderate sized mouth
(Fig. 280) and its angles do not extend backward behind the

342

LAMPREYS AND FISHES

eyes, which is the case in the large-mouthed species. Bass
move into the shallow waters to breed, usually selecting regions
where there are rocks or stumps around which the nests may
be hidden. In May or June, sometimes much earlier, the male
makes a basin on the bottom by fanning away the sand with
his tail until he reaches the mud three or four inches below.
Two or three females gather near and when the nest is finished
the male seeks out one of them, biting her cheeks and cajoling
her until she enters the nest area. When the eggs and sperm
are being shed the female lies on her side and the male is up-
right beside her. This process lasts but a few seconds at a
time but a female may stay within the nest for an hour or
two. The male may mate with two or three females but
he continually guards the nest and the eggs until they are
hatched. He not only tends the nest but guards the small
fry as long as they stay in it and swims about with them
afterward.

Size. — Up to 12 or 15 inches.

Distribution. — The small-mouthed bass is found widely dis-
tributed from the St. Lawrence River region to Arkansas,
and southward, living in cool streams not cold enough for
brook trout.

Fig. 281. — 'Common perch, Perca flavescens.

Perches and Darters — Percidcs

In the perch family are the yellow perch, the wall-eyed pike,
and a large number of dwarf perches or darters which live in

343

FIELD BOOK OF PONDS AND STREAMS

clear rapid streams. Darters and perches have two dorsal fins
— a spiny one followed by a soft-rayed one (Fig. 282). Their
scales are toothed on the free edges, making the body of the
fish feel rough to one's fingers.

Common or yellow perch, Perca flavescens. — The yellow
perch (Fig. 281) is one of the commonest fishes in ponds and
lakes, and one of the easiest to recognize. Its back is olive,
blending into brilliant yellow on the sides and under part of
its body, and the yellow of the sides is crossed by dark bars;
the lower fins are bright orange, especially during the breeding
season in April. Through the winter, perch stay in the deeper
water, ten feet or more, and large numbers of them are caught
by hook and line through holes in the ice.

Perch do not make nests of any kind but lay their eggs in
strings of jelly from two to seven feet long, twined about the
water weeds of the shallows. With its surrounding jelly each
egg is about one-eighth of an inch across and there may be
many thousands of them in a string. They are laid in March
and April or May, depending on the temperature, and hatch
in from ten to twenty days.

Size. — Reaches a foot in length but is usually 6 to 10 inches.

Distribution. — Great lakes region; eastern states.

Fig. 282. — Johnny darter, Boleosoma nigrum.

Darters. — Darters are so small and swift and brightly
colored that they take the same place among fishes that the
wood warblers do among birds. There are many kinds, re-
sembling each other so much that species are difficult to

344

LAMPREYS AND FISHES

separate. They all live in swift streams, lying on the bottom,
hidden among the stones, often supporting themselves by
their expanded ventral and anal fins, frequently resting with
their heads turned to one side. They make lightning-quick
darts and short stops like rabbits. They feed upon the insects
of the riffles, especially upon midge larvae.

Johnny darter, Boleosoma nigrum. — The "Johnny" or
tessellated darter is common in both swift and sluggish streams
and ponds, in New England and New York. It is about three
inches long, pale olive brown with black W-shaped markings
on its sides (Fig. 282). Its name "tessellated" refers to the
fine black flecking on its tail fin. In spring the males are
almost all black. The' Johnny darter often swims about over
a mud bottom, an unconventional place for darters.

Size. — Up to 2 and }4 inches.

Distribution. — Eastern states, and westward to Pennsyl-
vania, Great Lakes, Dakota.

Fig. 283. — Miller's thumb, Cottus bairdii.
Sculpins — CottidcB

Miller's thumb, mufflejaw, muddler, C?)ttus. — These are
grotesque little fishes with heads too large for their bodies
and flattened like the proverbial miller's thumb. Fullgrown
ones are not usually more than five inches long. Their general
color is olive green or brownish, speckled and mottled with
darker brown, the whole pattern matching the bottom of the
clear streams and ponds where they hide. They are smooth-
skinned except for fine prickles behind the front fins and
the warty roughness on the head.

345

FIELD BOOK OF PONDS AND STREAMS

Two similar species of miller's thumbs, Cottus hairdii (Fig.
283), and Cottus cognatus, are common in clear, rocky brooks
and lakes. Although they most commonly hide on the stony
bottom they are also frequently found in tangles of stonewort
and pondweed. They feed upon insects, small crustaceans
and algae; occasionally they eat the eggs of other fishes.

They spawn through April to July. The eggs are salmon-
colored, about one-eighth of an inch in diameter, and laid in
a grape-like cluster of a hundred or two, glued to the under
sides of stones in shallow water, where there is more or less
current. The male seems to select the site, while the females
tarry about. Later one of them joins the male and then
deposits her eggs. He loiters near the eggs protecting them
until they hatch.

Size. — Small, up to 5 to 6 inches.

Distribution. — Canada to Georgia and westward to Mis-
souri.

346

CHAPTER XVIII

AMPHIBIANS
Salamanders, Frogs, and Toads Found In or Near Water

Toads forage through city parks and gardens, and frogs
raise their spring choruses from every roadside swamp. Any-
body who is acquainted with amphibian life knows the heavy
wet plash of the bullfrog, the translucent daintiness of the
red newt half hidden beneath wet leaves, and the industry of
the common toad, collecting insects near the rose bushes at
evening, intimate and friendly, yet aloof.

General form and habits. — Amphibians generally spend
their youth in the water, leaving it only to return again. But
there are notable exceptions. Red-backed salamanders never
go into water even to lay their eggs, while a few others like
the mud-puppy and the hellbender do not go out of it. With
rare exceptions, our native frogs and toads leave the water
but return to it. Like fishes and reptiles, amphibians are
cold-blooded, back-boned animals, but amphibians seldom
have scales or bony plates while fishes and reptiles are usually
covered with them. Almost all breathe by gills during their
larval period and later they have lungs or other devices; but
all their lives most of them take oxygen through their thin
moist skins. The salamanders have tails and are shaped so
much like lizards that they are continually mistaken for them,
m spite of their soft, scaleless skins. The frogs and the toads
are tailless after they have grown beyond the tadpole stage.

347

FIELD BOOK OF PONDS AND STREAMS

Amphibians are timid animals and their chief defense is in
flight or concealment. They do net bite and they neither
scratch nor sting. None of our native species is poisonous
or harmful. It is true that the skin of a maltreated toad gives
off a milky fluid which is peppery and irritating; any dog
which picks up a toad usually drops it quickly, but is rarely
badly poisoned by it.

Habitat. — Frogs and toads live in ver}^ difl'erent places
during different seasons and stages of their lives. So long as
they are tadpoles or lar\^ae they all live in the water, but the
air-breathing adults take to the land, the frogs generally
keeping to marshes and meadows and damp woods, and the
toads going to shaded spots in gardens and roadsides. They
vary in their choice of winter hibernation places; some hide
beneath stones, others dig into the bottoms of streams and
ponds. But in spring, they are sooner or later to be found in
the water; there they lay their eggs, and there the fishlike
tadpoles hatch and grow to adult form. American sala-
manders are more apt to spend their lives either entirely in the
water or entirely upon land, but some of them, like the spotted
salamander, Amhy stoma maculatum, live in the water until
they become adults, then clamber out and live on land
hidden beneath stones and logs, but return to the water to
lay their eggs.

Food. — Frog and toad tadpoles are mainly vegetable
feeders, preferring filamentous algae like Spirogyra or desmids
and diatoms. After transforming they become carnivorous,
eating insects, snails, worms, and the like. In their new form
even the shape of the food canal is changed, from the long
intestine coiled like a watch-spring such as can be seen through
the body wall of a big bullfrog tadpole to the short one charac-
teristic of carnivorous animals (Fig. 284). Salamanders are
carnivorous in both larval and adult stages, thriving upon
worms and water insects, mollusks, and small tadpoles of their
own species.

348

AMPHIBIANS

Fig. 284. — Tadpole (A) and young frog (B) with
their body walls spread open, showing the long
watch-spring intestine of the herbivorous tadpole
and the short food canal of the frog, which has be-
come carnivorous.

Breeding habits. — The sexes are easily distinguished,
especially during the breeding season. Male frogs have
swollen thumbs (Fig. 285) or thumb-pads while the females

\lj

1 a. 3

Fig. 285. — Right front foot of frog showing shape
of the thumb in different sexes: i, male with swollen
thumb, in the breeding season; 2, male with thumb
of smaller size as it is out of the breeding season; 3,
female.

have more slender ones; in male toads the upper surfaces of
the thumb and first finger are rough and horny. In male

349

FIELD BOOK OF PONDS AND STREAMS

salamanders the lips of the cloaca are swollen and wrinkled
and in some species the males have keeled tails and on the
inner sides of their hind legs the skin is thick and blackish
(Fig. 288).

In spring, frogs and toads congregate in the ponds and their
voices, chiefly male, join in the famiHar choruses. They mate
soon after they reach the water. Climbing upon the back of
the female the male clasps her behind her forearms, and
presses his homy thumb and finger pads against the sides of
her body. The two continue in this position for hours, often
for several days. They do not eat and, although usually
shy, at this time they can easily be picked up in the hand.
When they are caught the male generally keeps his tight hold
on the female even when the pair is roughly handled. Under
natural conditions, as soon as the eggs leave the body of the
female the male sheds the sperm cells and fertilization takes
place in the open water; then the pair separate.

Many male salamanders deposit gelatinous capsules of
sperm cells, the spermatophores (Fig. 289), upon twigs and
leaves in the pond. While this is going on the female follows
the male about and clasping the sperm-filled top of one of
these between the lips of her cloaca, pulls it inside where the
sperm cells are stored in special sacs (spermathecas) until the
eggs are fertilized. Among the spotted newts and other sala-
manders an elaborate courtship precedes the depositing of
the spermatophores.

Life history. — Although different species have their own
peculiarities, amphibian life histories are in general very much
alike. The young forms or larvae are fish-shaped, with tail-
fins and gills. Very young toad and frog tadpoles have
suckers by which they can suspend themselves well up in the
water where there is plenty of ox3'gen and no mud; most
young salamander larvas have "balancers" and their gills are
large and bushy (Fig. 286). Transformation to the adult
form progresses slowly, the time required differing greatly in

350

AMPHIBIANS

Fig. 286. — A. — Young frog tadpole showing i,
gills ; 2 , fin ; and 3 , suckers . B . — Larva of salamander
{Amhy stoma) with I, gills; 2, fin; 3, balancers; and 4,
front legs.

different species. This involves great changes in any amphi-
bian, the development of legs and lungs, absorption of gills
and shifts in the circulation, and in toads and frogs, a dif-
ferent shaping of the mouth and a new kind of teeth, the
absorption of the tail and a making over of the food canal
(Fig. 284). The insect-catching toad has a digestive system
which is very different from that of the alga-eating tadpole.

Suggestions for aquarium and vivarium study. — In the
following table the months named are those in which these
frogs and salamanders are most easily captured but they can
be found at other times too.

March to April. — Eggs and larvae, spotted salamander,
Amhystoma maculatum (PL XIX). With a lens the blood
can be seen circulatirig in their gills even before they hatch
out of the jelly. In an aquarium larvag at first only need
plenty of water and a few plants to oxygenate it (p. 39).
When they are older they can be fed on small crustaceans and
worms (EnchytrceidcB).

April to May and September to October. — Adult spotted
newts, Triturus viridescens (PL XIX), will live the year round
in shallow water with a stone or two placed in it so that they
can climb out. They mate readily in the aquarium either in

351

FIELD BOOK OF PONDS AND STREAMS

their spring breeding or fall mating season. Young red
newts (PL XIX) are most at home in a damp ferner}^ Both
young and older ones can be fed bits of meat, earthworms or
raw beef.

April to October. — Like red newts, the spring peepers,
Hyia crucifer (Fig. 302), will live the year round in a damp
vivarium. They only need plenty of moisture and occasion-
ally a few live worms and insects.

April to May a7id Atigusi to September. — Tree frogs, Hyla
versicolor (Fig. 301), also live well in a damp shaded vivarium
(p. 40).

March to November. — Bullfrog and green frog tadpoles will
live on algaj for months but a medium sized aquarium holding
about a gallon or more of water should have only two or three
in it.

Giant Salamanders — CryptobranchidcB

Hellbender, Cryptobranchus alleganiensis. — ^The hell-
bender is an animal which is rarely discovered but once seen
it is warranted to hold one's attention. It is commonly a foot
and a half long, the largest salamander in North America.
Its body is olive colored or reddish brown with darker patches
and is so broad and flat that it almost completely overshadows
the short, bowed-out legs (Fig. 287). Its small eyes are nearly
hidden in an expanse of slimy forehead. The thick oozy skin
fits loosely, gathered into fleshy folds along each side of the
body, and when lying quietly on the bottom a hellbender
looks like an old, wrinkled, and defunct cucumber.

Habits, habitat. — Hellbenders stay in the water all their
lives. Although they have lungs they do not use them, but
rely chiefly on their skins for respiration ; their gill-slits which
open into the sides of the throat do not seem to have any
function. Hellbenders 'live in crevices among rocks or in
woody debris in creeks and rivers.

AMPHIBIANS

Fig. 287. — Hellbender and eggs, Cryptobranchus
alleganiensis.

Food. — They eat all kinds of small water animals, foraging
only at night.

Breeding habits. — In breeding habits hellbenders are more
like fishes than salamanders. Like the sunfish and other
fishes, the male hellbender clears a basin-shaped cavity or nest
on the bottom, usually in September. There he awaits the
female, which enters it, and as she lays her strings of eggs he
sheds the spermatozoa over them, afterward chasing her from
the nest and standing guard above them, but occasionally
eating a few himself (Fig. 287).

Size. — Length of adult 12 to 18 inches.

Range. — Western New York and central Pennsylvania to
Louisiana, and westward to Iowa.

Newts — PleurodelidcB

Red newt, spotted newt, Triturus viridescens. — The "red
eft" or "red lizard" cf the woods, and the "spotted newt"
of the ponds are different color phases of the same animal,

353

PL XIX. — Salamanders: from above downward, spotted
newt, Tritiirus viridescens , adult; red phase usually found on
land; larva; two-lined salamander, Eurycea hislineata; dusky-
salamander, Desmognathus fuscus; spotted salamander, A mhy-
stoma maculatum.

PLATE XIX

G^-^ti^i C.f' »^fff^t

1

AMPHIBIANS

^J

^■*>«t. - — "^^ ^- •-■'•■

#>^t^^^^a^^^^K«

Figs. 288. — Spotted newt, Tritunis viridescens,
in breeding season: i, male showing tail-fin, swollen
cloaca {c), and black ridges on inner surface of
the hind legs {d); 2, female which has a generally
slender form.

Tritunis viridescens, one of the commonest salamanders in
the eastern states. (PI. XIX.)

Adult Tritiirus, the "spotted newts" or "vermilion
.spotted newts, " live in ponds, and in quiet stretches of mean-
dering streams. The upper surfaces of their bodies are
reddish or olive or dark green and the underparts are lemon
yellow covered with fine black dots, and along each side of the
back there is a row of scarlet dots ringed with black. The
male has a swollen cloaca, stocky hind legs, much stouter
than the front ones, and their inner surfaces are covered with
thick black ridges of skin during the breeding and mating
seasons (Fig. 288, i). The cloaca and tail fin become especial-
ly conspicuous during these times. The females have del-
icately molded legs, the hind ones nearly the same as the
front ones and without the blackened skin folds (Fig. 288).

Habits, habitat. — Young "red newts" wander about the
woodland near their home waters, moving hesitantly in and
out among the dead leaves. A red newt peering from the
curve of a dried oak leaf is the picture of alert shyness. On
foggy or rainy days they come out of their hiding places to
forage for insects or whatever small animals they can find.
Some of them are brick red, others are orange colored, but,
like the adults, all have a single row of scarlet black-bordered
dots on each side of their backs.

355

FIELD BOOK OF POINTDS AND STREAMS

Food. — Whether in the water or out newts are carnivorous.
In the ponds they eat snails, small crustaceans, and their own
larvae.

Breeding habits. — The breeding season is from March to
April but they occasionally mate all through the year, especial-
ly in the autumn. When mating, the male seizes the female,
clasping his hind feet just behind her front legs. Holding
her firmly he bends his own body in an S-shaped curve and
begins rubbing the side of his head against hers, and at the
same time steadily tapping his tail against her body. Occasi-
onall}^ he yanks and shakes her and together they shift and
twist their bodies. This performance may go on for hours
and as readily in aquaria as in the pond. Soon after the pair
separates, the male deposits the white vase-shaped sperma-
tophores (p. 357). Dozens of these can often be seen scattered
here and there on submerged leaves. As the male moves away
from the spermatophore which he has deposited, the female
follows him and crawls over it, taking its mass of sperm
cells into her cloaca (Fig. 288). She lays her eggs singly, each
in a capsule of jelly, placing them on leaves or in the axils
of leaves and stems of Chara and Elodea. These are brown
at one end, creamy or light green at the other, and 80 to 100
of them may be laid by one female.

Life history. — The newly hatched larvae have branching
gills, "balancers," the buds of their front legs, and fish-like
tails (Fig. 286). Toward fall they gradually lose their gills
and acquire lungs, and their color changes from green to red.
Their further migrations and color changes vary; in many
places they climb out of the ponds and spend at least one
winter on land, while in some regions they do not appear to
leave the water at all. Sizes and ages at which the young,
usually brick red sub-adult finally matures seem to depend
upon differences in food, temperature of the water, character
of the ponds, and perhaps upon other still unknown factors.

Vivarium. — Both young "red newts" and adults are most

356

AMPHIBIANS

at home in a vivarium with a "pool" and a damp mossy floor
(p. 40) although the adults can get along almost anywhere so
long as they are given a little water and kept cool. They
eat fresh meat, showing little preference between pieces of
beefsteak and earthworm except when the worm wriggles.

Size. — Length of adults 4 inches or less.

Range. — Common, eastern United States and Canada.

Mole Salamanders — Ambystomidce

Spotted salamander, Ambystoma maculatum. — The eggs
of this and other species of Amhystoma are far more familiar
than the secretive, nocturnal animals which lay them. Spot-
ted salamanders have large, stout bodies, and broad, flat
heads. Their upper surfaces are shining black scattered over
with a few large, round yellow spots; underneath they are
slaty-gray, sprinkled with bluish-white flecking (PI. XIX).

Habits, habitat. — ^Through most of the year the adults
skulk beneath logs and stones, in any dark, damp place in
pastures and light woodland; they have also been found in
lawns and gardens, even in cellars of houses. During the
nights of early March and April they come out of their hiding
places and migrate into ponds. The larvae live in spring-
fed ponds and streams.

Breeding habits. — Adults congregate often in great num-

FiG. 289. — Eggs and spermatophore of the
spotted salamander: i, small cluster of eggs attached
to leaf, showing coverings of jelly; 2, spermatophore.

357

FIELD BOOK OF PONDS AND STREAMS

bers in certain small ponds and slow streams. Not one can
be seen during the day though each morning may show dozens
of new egg clusters, but at night they can be easily found with
a spotlight. The males deposit spermatophores about half
an inch high which look like glass push-pins and hold hundreds
of spermatozoa (Fig. 289). The females crawl over these,
taking the spermatozoa into the cloacal chamber (Fig. 288),
where they are held ready to fertilize the eggs that are
always laid during the night or very early in the morning.
Each egg is enclosed in an envelope of jelly and the whole
cluster is covered by a thick layer of it (Fig, 289). The eggs
are larger and further apart than frogs' eggs (PI. XX).

Life history. — The greenish brown larvae hatch in two or
three weeks according to the temperature. They are about
half an inch long and have noticeably flattened heads, "bal-
ancers, " the stubs of front legs, and a lusty growth of gills
(Fig. 286). During their transformation in late fall and
simimer the gills stop growing and gradually become absorbed.

Aquarium and vivarium study. — Amhystoma eggs are so
large that they show early stages of development ver>' clearly,
much better than frogs' eggs, but like them they grow very
rapidly, and in the warm water of an aquarium these early
stages are passed through in a few hours. The larvae can be
reared in dishes of water stocked with filamentous algae, and
later (as their legs develop), fed with small worms (p. 351).
Adults can be kept the year round in a damp vivarium and
fed on bits of beef or pieces of earthworms.

Size. — Adults 6 inches long or more.

Range. — Locally common in east and central North America.

Tiger, salamander, Ambystoma tigrinum. — Although tiger
salamanders are rare in many localities, they are very widely
distributed in the United States and their life history is one
of the most interesting among salamanders. They are heavily
built and their rusty black bodies are covered with blotches
of yellow running together in irregular marbling and cross-

358

AMPHIBIANS

Fig. 290. — I, Adult tiger salamander, Amby-
stoma tigrinum; 2, axolotl or larva which matures
without transforming (axolotl found only in south-
western United States).

bars, except on the under surfaces, which are plain gray (Fig.
290, i). These yellow spots and their yellow chins distinguish
them from the marbled salamander, Amhystoma opacum.

Habits, habitat, food. — The fully transformed adults hide
beneath stones and logs near ponds or in moist places where
they forage for worms and ground insects during the night
or in rainy weather. The larvae live in cold, spring-fed ponds.

Breeding habits. — Their breeding habits are much like those
of the spotted salamander, Ambystoma maculatum, and the
egg masses are very similar (Fig. 289).

Life history. — All tiger salamanders start life as typical
salamander larvae, breathing by gills and growing like other
aquatic salamanders. In many regions, especially our north-

359

FIELD BOOK OF PONDS AND STREAMS

em and eastern ones, these salamanders transform typically,
their lungs develop, their gills shrink, and they finally climb
out on land as air-breathing adults. But in other regions
such as western Texas and the southwest, and under certain
conditions, the larvae continue to grow to full adult size with-
out changing their form or losing their gills and are known as
axolotls (Fig. 290, 2).

Although these axolotls appear like overgrown lar\^ae, their
reproductive organs mature, the females lay eggs and the
males deposit spermatophores containing sperm cells which
fertilize them. Generations of such axolotls may follow one
another for a long time if their surroundings remain the same,
but a sudden change of climate or lack of water may shift
their course of life. Then their gills shrink and they trans-
form into ordinary air-breathing adults whose offspring will
lose their gills and transform into t3^pical adults. This cycle
may be repeated over and over till conditions change again.

Size. — Length of adults 7 to 8 inches.

Range. — The entire United States and southern Canada;
rare in the eastern states, especially in New England ; abund-
ant in the western and southwestern United States where the
axolotl form is often treated as a separate species.

Fig. 291.-
ma opacuni.

-Adult marbled salamander, Amhysto-

;6o

AMPHIBUNS

Marbled salamander, Ambystoma opacum. — The general

color of the marbled salamander is slaty-gray turning to bluish
beneath the body. Its large spots and blotches form about
fourteen irregular grayish-white bars (Fig. 291), never yellow
like those of the spotted and the tiger salamanders nor in
small flecks like those on Jefferson's salamander.

Habits, habitat. — 'Although they go to the ponds to breed
they are likely to hide under stones on dry hillsides or to
burrow into earth, often in sandy places.

Breeding habits. — Dr. A. H. Wright found clusters of A,
opacum eggs in autumn under logs and driftwood, in moist
soil but not in the water. Their outer coats were tough and
very unlike other Ambystoma eggs.

Size, — Length of adult about 5 inches.

Range. — Only occasionally common; eastern and central
regions of North America; coastal Massachusetts to Texas;
up Mississippi Valley to Illinois.

Fig. 292. — Adult Jefferson's salamander, Amby-
stoma jeffersonianum.

Jefferson's salamander, Ambystoma jeffersoniantmi. — ■

Jefferson's salamanders are uniformly dark brown all over
but they may have small blue white flecks along their sides

361

FIELD BOOK OF PONDS AND STREAMS

(Fig. 292). On the ground the old adults appear plain brown,
the flecks of pale blue on their undersides being hardly ap-
parent, but on the younger ones the blue is conspicuous and
the spots are scattered over the body and the back of the head
as well.

Habits, habitat. — The adults live beneath logs, in rotting
stumps, beneath the litter of sawdust piles, and under stones.
They migrate to the ponds even earlier than the spotted
salamanders. The larvcE live in sphagnum ponds, cold quiet
streams and woodland ponds.

Breeding habits. — They deposit their eggs in email firm
masses of jelly attached to submerged twigs, sometimes in the
same pond with those of the spotted salamander with which
they are confused even by experts. But these eggs are gen-
erally laid earlier and in smaller masses, under two dozen eggs
in a clump.

Size. — Length of adult about 6 inches.

Range. — Hudson Bay to Arkansas, Nova Scotia to Virginia
or even further south.

Lungless Salamanders — PlethodontidcB

Dusky salamander, Desmognathus fuscus. — Dusky sala-
manders stay in crevices and under stones in moist earth
near shady streams. The adult dusk}' has a stout body with
a reddish brown back and gray under parts (PL XIX). On its
back there are two irregular rows of black spots and upon its
sides a mottling of black; a white line extends from the eye
to the angle of the jaw.

The larva is uniformly brown on the back except for two
rows of small light spots which extend along it upon each
side. Its gills are more or less prominent unless the change
to adult form has already begun. Both larvae and adults have
a peculiar rigidity in their lower jaws, and they use them as
entering wedges when they are pushing their way under stones.
Whenever a dusky salamander opens its mouth it holds the

362

AMPHIBIANS

lower jaw straight as a rod and lifts the upper jaw away from
it.

Habits, habitat. — The adults hide under stones near shallow
streams, and the larvas live in running water. Neither larvae
nor adults seem comfortable unless they are hidden beneath
something. In the swift shallows of certain streams one young
dusky will flash out from almost every stone which is up-
turned.

Food. — Adults and larvae are carnivorous; their diet is
chiefly of insects, earthworms, and snails.

Breeding habits. — They lay their 15 to 20 creamy white
eggs in moist cavities or beneath stones, very near the edge
of a stream. There are one or two clusters, closely guarded
by the female, which usually lies with nearly all of them
in contact with her body. They hatch in about eight weeks.
In western Massachusetts eggs have been found from mid-
June to September.

Life history. — The larvae live on land until they are 15 to
16 days old and about three-quarters of an inch long. Then
they enter the water and remain there 8 to 9 months, trans-
forming to adults the following spring, when they go out on
land to breed. A female will continue to guard her eggs even
in captivity.

Vivarium. — An adult dusky will burrow down, completely
hiding itself in the dirt unless stones are provided for it. Dr.
I. W. Wilder once found two adults entirely covered in the
dry earth of a terrarium where they had been living for two
years.

Size. — Length of adult male 53^ inches; female smaller.

Range. — Common. Canada to Mississippi, westward to
Illinois.

Red salamander, Pseudotriton ruber. — This bright coral-
red salamander is locally common in and near streams in the
eastern states except New England. The older animals are
purplish brown but the young adults are coral-red with small,

363

FIELD BOOK OF PONDS AND STREAMS

Fig. 293. — Young adult red salamander, Pseudo-
frit on ruber.

irregular black spots scattered over their backs (Fig. 293).
Their sides and under parts are lighter, unmarked and so
transparent that the pulsations of the heart can easily be seen
through the body wall.

Habits, habitat. — Like the two-lined salamander, it crawls
under flat stones, sometimes in swampy places, but more
often in small streams; in winter it lies beneath stones in
shallow rapids. This is a lungless salamander which takes
oxA,'gen through its throat membrane and moist skin. It takes
little risk of drvdng, keeping to water or damp places, moving
about only at night.

Food. — Its diet of worms and insects is similar to that of
other salamanders.

Breeding habits. — The red salamander la3^s its fifty or more
eggs in the fall, gluing them to the underside of a stone where
they are in the constant wash of the current. The eggs are
clustered in small patches of a dozen or two but each one is
attached separately by a jelly-like stalk.

Life history. — Although the eggs hatch in October or
November, the larvse remain relatively inactive through the
winter months, but in spring they begin feasting upon little
crustaceans or anything else which is lively and within their
capacity; by mid-spring they are about an inch long. When
they are about four inches long and two 3^ears and a half old

364

AMPHIBIANS

their gills begin to shrink and their brownish color turns to
the bright coral-red of the young adult.

Vivarium. — Red salamanders live well in the ordinary
damp shaded vivarium (p. 40) ; they thrive upon bits of
earthworm and fresh meat.

Size. — Average length of adult 4 to 5 inches.

Range. — Locally abundant in the eastern states except New
England; Albany County, New York, to Ohio, Kentucky,
New Jersey, North Carolina, westward to the Mississippi
River.

Two-lined salamander, Eurycea bislineata. — The two-
lined salamander is small, slender, and very active and hides
beneath stones along brook borders (PL XIX). Its ground
color varies from brown to yellowish. On each side of the
back a dark line, gray or brown or black, extends from the
eye backward along the tail ; below the dark lines the sides of
the body are finely speckled with black and the under parts
are yellow.

Habits and habitat. — The adults hide beneath flat stones
in the water-soaked mud and sand of brook-sides, slithering
and jumping out with amazing rapidity when disturbed.
The larvce, distinguishable by their gills, grow nearly as long
as the adults and stay in the same places, whence they dash
out with flash-like suddenness when the stones are moved.

Food. — They live mainly upon water insects, worms, and
small crustaceans, seeking these by daylight in the shallow
water.

Breeding habits. — They lay their eggs as early as April and
as late as the middle of August, on the undersides of stones
in flowing water. There may be as few as a dozen or two or
as many as sixty hanging from one stone, each one fastened
to it by a separate stalk of jelly.

Life history. — The change from larval to adult form is very
gradual ; the salamanders may be at least two years old before
it is completed. The larvee are about 2 inches long before

365

FIELD BOOK OF PONDS AND STREAMS

they lose their gills. In some regions the adults leave the
brooks in the fall and hibernate under stones near the stream.
They are often abundant along the borders or in the beds of
shallow brooks.

Size. — Length of adult 3 to 4 inches, sometimes smaller.

Range. — From Maine to Florida and westward to Louisiana.

Fig. 294. — Adult purple salamander, Gyrinophi-
lus porphyriticiis.

Purple salamander, Gyrinophilus porphyriticus. — Full-
grown purple salamanders are light reddish with mottled
shado wings of a darker tone (Fig. 294).

Habits, food. — They stay in small cold streams and little
runnels all their lives, hiding in hollows beneath stones and
feeding on the riffle organisms (p. 21) which continually
gather around them.

Breeding habits. — 'Neither their breeding habits nor their
eggs are well known although the adults are abundant in
certain streams. Adults, and larvag evidently two years old
or more, are found in the same places.

Size. — Adults 6 inches long.

Range. — Locally common, eastern states; westward to Ken-
tucky and Tennessee.

Mud-puppies — Necturidce.

Mud-puppy, water-dog, Necturus maculosus. — A mud-
puppy looks like a frog-puppy, or a dachshund in a froggy

366

AMPHIBIANS

Fig. 295. — Mud-puppy, Necturus maculosus.

masquerade. Its long body is low-slung on futile looking
legs and the dog-like head is flanked by bushy "ears" or gills,
which swing rhythmically back and forth as it breathes (Fig.
295). Its mottled brown body is blotched with blue-black
on the sides and back, the whole color scheme matching the
stream bottom so well that a mud-puppy easily goes unnoticed,
especially when its red gills are not expanded, as is often the
case in a stream where there is plenty of oxygen.

Habits, food. — Mud-puppies live in the water all their lives,
in rivers and creeks, crawling about mostly at night in pro-
tected places among stones and debris, feeding upon the yield
of the stream bottom — water insects, snails, fish eggs, and
small fishes. .

Breeding habits. — Mating probably occurs in the fall and
sperm cells can be found then in the cloacal chamber of the fe-
males. In the following late spring or early summer, mud-
puppies lay their eggs, gluing them on flattened stones and
guarding the place until after the young larvae have hatched.

Size. — Commonly a foot long.

367

A

FIELD BOOK OF PONDS AND STREAMS

Range. — Mud-puppies are very common in certain rivers and
lakes. In the upper waters of many streams which flow into
the Atlantic Ocean; valleys of the Great Lakes and the
Tvl ississippi north of the Gulf Stream; Lake Champlain and
the upper Hudson; southward into northern Alabama and
Arkansas.

Toads and Frogs. — A7tura.

Toads and frogs are tail -less amphibians with four legs
(Fig. 296). Toads are heavy bodied and awkward, their skins

rULYTl

ttbict toe boio

Fig. 296. — Diagram showing the external struc-
tures of toads and frogs.

are rough and warty, and back of each eye the}'' have a glandu-
lar swelling, the parotid gland.

Toads — BnfonidcB

American toad, Bufo americanus. — The American toad
is the familiar amphibian throughout the eastern states. On j
quiet summer evenings it comes out from under verandas and
sits on warm door-stones or it patrols the garden for insects.

368

AMPHIBIANS

Between long silences it utters its single "wheep," high and
sudden, like an exclamation.

This toad has a thick-set, chunky body and is short-legged
and broad-toed ; its skin is conspicuously warty and the head-

FiG. 297. — American toad, Biifo americanns.

crests are wide and kidney-shaped (Fig. 297). In some
localities it is confused with Fowler's toad, which is more
slenderly built and has a smoother skin, especially on the
under parts (Fig. 298). In a few localities as on Long Island,
New York, Fowler's toad takes the place of the American
toad. The color of the American toad varies from light to
darker brown according to its own temperature and activity.
It is usually predominantly red-brown with patches and bands
of lighter brown; the warts and parotid glands are likely to
be a rich red-brown. The male is smaller. than the female
and her throat is grayish white while his is nearly black.

Breeding habits. — In early April, American toads come
out of their winter burrows, beneath flat stones or logs, and
begin their evening migrations to the ponds. By the middle
of that month numbers of them appear in the ponds, and their
sweet, tremulous calls sound forth uncertainly here and there.
The full toad chorus does not begin till the last week in April
or the first in May, and then it goes on in daytime or evening,

369

FIELD BOOK OF PONDS AND STREAMS

but after the middle of May, the day voices cease though the
evening notes may be heard till midsummer. Males reach
the ponds slightly earlier than the females, but mating occurs
as soon as both sexes have arrived.

Life history. — Toads lay their eggs in May, almost always
in quiet water. They are in two long, curling tubes of jelly,
each containing a single row of black eggs, four to twelve
thousand of them from one toad. In the water the jelly
swells and gathers dirt, and pond bottoms are often covered
with these dirty, twisted ropes, containing myriads of develop-
ing toads (PL XX). The eggs hatch into black tadpoles
within five to twelve days, depending upon the temperature.

From the middle of June to late July, shallow waters swarm
with tadpoles, transforming into toads. Young toads gather
on the shores, hopping up the banks and into the grass, meet-
ing their enemies — birds, snakes, frogs — and being eaten by
thousands. But the survivors persevere, and forage along
the stream side, finally departing for higher ground.

In July and August the old toads leave the ponds and scatter
into the gardens and fields, feeding there until they go into
hibernation for the winter.

Size. — Male 2 to 3 inches; female larger.

Range. — In most regions east of the Rocky Mountains from
Mexico to Great Bear Lake; southern states.

Fowler's toad, Bufo fowleri. — In some parts of New Eng-
land, Fowler's toad is commoner than the American toad or
takes its place. It comes out of hibernation much later;
Dickerson says of it, "In late May and June the toad chorus
in Rhode Island consists mainly of the voices of Fowler's toad,
with only an occasional sweet note from the American toad.
In July it is rarely that we hear any voice but that of Fowler's
toad."

Its slender legs make it a good jumper, almost as agile as
a frog. It is drab, yellowish, or greenish gray with irregular
spots of black or dark brown; its under parts are smooth

370

AMPHIBIANS

Fig. 298. — Fowler's toad, Btifofoivleri.

skinned and white, seldom spotted as they often are in the
American toad (Fig. 298). It has a harsh short trill while
the American toad's call is a prolonged and musical one.

Habitat. — It frequents the same gardens and ponds as the
American toad.

Breeding habits. — Its breeding season is from two to three
weeks later than that of the American toad. The mating
call is a weird and mournful metallic droning.

Life history. — The eggs are laid in tangled tubes of jelly,
like those of the American toad (PI. XX), but they are often
in double rows. The young develop quickly, and before fall
the small toads in the garden show all the markings character-
istic of their parents.

Size. — Male 2 to 3 inches; female slightly larger.

Range. — Central New England to Georgia, westward to
Michigan, common in regions of Rhode Island, Massachusetts,
Connecticut, New York, Long Island.

Burrowing Toads — Pelobatida

Hermit spadefoot, spadefoot toad, Scaphiopus holbrooki. —

Although spadefoot toads live in nearly every part of eastern
North America, they are not very well known because of their

371

FIELD BOOK OF PONDS AND STREAMS

Fig. 299. — Spadefoot toad, Scaphiopus holbrooki,
and I, foot enlarged.

shyness and persistent habit of digging into the ground.
When kept in boxes of damp earth they hide themselves in
their burrows, coming out only at night, or occasionally on
dark days.

They can pull their prominently bulging eyes down on a
level with the surface of their heads. The pupil of the eye is
a vertical slit like a cat's; in all other frogs and toads it is
round. The upper parts of their bodies are dark brown
streaked with longitudinal bands of yellow; their undersides
are white or pink (Fig. 299}.

Breeding liahits. — Spadefoots come out of their burrows
at the end of April or later and are in the ponds or near them
until August, their migrations almost always occurring after
a long rain storm. Large numbers come simultaneously into
the pond. They stay there only two or three nights, but
during that time the males keep up a chorus of loud calls,
whose sound is increased by the resonator throat sac three
times the size of the head. Spadefoots leave the pond as soon
as the eggs are laid, and go back to their old burrowing habits.

372

AMPHIBIANS

Size. — Length 2li inches; female not much larger than
male.

Range. — Common ; all of eastern North America, Gulf States
and Texas and northward into Arkansas.

Tail-less Amphibians or Frogs

Like toads, frogs are tail-less amphibians, but they are
stronger, more active jumpers, with moist skins and without
rough, warty swellings (Fig. 309).

Tree Frogs — Hylidce

Tree toad, common tree frog, Hyla versicolor. — As the

scientific name suggests, the colors of the tree toad are change-
able and it may be white or gray or green or brown. It has
a dark irregularly star-shaped spot on the back, oblique dark
stripes on the head, and dark cross bands on the legs, but all

Fig. 300. — Tree toad, Hyla versicolor, with vocal
sac inflated.

of these may be indistinct or invisible (PI. XXI). Its white
under parts are washed with bright orange-yellow, especially
the folds of the hind legs. Like the spring-^peeper and other
climbing frogs, it has sticky pads on the tips of its toes (Fig.

301)-

Habits, habitat. — This is a tree climber whose long, reedy
tremolo is familiar on summer evenings, and in the sultry
hush before afternoon thunderstorms. Its favorite perch
is in the crotch of a limb, where it can hardly be told from
the gray bark. Sometimes tree frogs rest on leaves of low
shrubs, where they may scarcely be discovered except by

373

FIELD BOOK OF PONDS AND STREAMS

accident, so closely do they match the color of leaves. They
are very much at home about houses, even climbing into
veranda flower boxes, and they can live comfortably in a glass-
covered fernery if the air is kept damp and they are occasional-
ly fed with small worms and insects.

Fig. 301. — Tree toad with its body pressed against
the glass side of a fernery.

Breeding habits. — By the last of April or first of May tree
toads have come out of their winter hiding places on land and
are on their way to their breeding ponds. By the middle of
May their high resonant voices are raised in full chorus ; they
begin calling in the early afternoon, especially on warm, moist
days, and keep it up well into the night. The gnome-like
males sitting on the lily pads with their vocal sacs ballooned
out into pearly translucent globes will go on singing in the
full flare of a flashlight (Fig. 300). Probably they come to
the ponds before the females. In a week's thorough search
during the earliest part of the breeding season, Wright found
males each evening, but never saw any females. Tree toads
usually mate at night. By the first of June they begin to
lay their light brownish eggs which are attached in small
groups to plant stems, always at or near the surface of the
water.

Life history. — The scarlet-tailed tadpoles grow very rapidly,

374

AMPHIBIANS

and about three weeks from the date when the eggs are laid
their hind legs are beginning to show, and in seven weeks the
little frogs, now about half an inch long, are ready to leave
the water.

Size. — 2 inches, but half -grown ones about an inch long
are common.

Range. — Throughout eastern North America, west to

Kansas.

Fig. 302. — Spring peeper, Ilyla cnicifer, with vocal
sac inflated.

Spring peeper, Hyla cnicifer (formerly H. pickeringi). —

The best field marks of the spring peeper are its small size,
and the dark multiplication sign on its back (PI. XXI). Its
general color varies from light fawn to dark brown. . The
whole body is delicately translucent and the under parts
are white, washed with yellow, though in the male the throat
is brown.

Habits, habitat. — Spring peepers cling to dead grass-
blades by the pond-side uttering their shrill peeping, one of the
earliest calls of spring in the ponds and marshes. They begin
to sing in March, when the spotted salamander, Amby stoma
mactilatum, is laying its eggs, and they continue till the end ■
of their own breeding season, often late in May. After that
they 'scatter through swamps and meadows and are only
occasionally seen.

Food. — They eat worms and small insects, their diet being
similar to that of other frogs but simpler.

Breeding habits. — Pond shallows and wet hillocks of grass
about the margins are favorite breeding places. There on
warm evenings in early May their high-pitched, clear chorus

375

FIELD BOOK OF PONDS AND STREAMS

can be heard for half a mile. As one approaches, the chorus
ends, but after a brief silence voices start up here and there,
and if it is quiet enough, a voice finally rises from the grass
hillock at one's feet. The flashlight may not reveal the frog
at first, but after continued scrutiny, his white vocal sac
shines forth in the light (Fig, 302). Clinging there, swollen
up like a pouter pigeon, he will keep on uttering his call in the
full glare of the light so long as no sound or movement dis-
turbs him. After one peeper is found, a dozen more are
usually discovered in all positions, one in the center of a lily
flower, others on the floating pads or half-way up the iris
leaves.

The males come to the breeding ponds before the females,
and always seem to be more numerous. Peepers begin to
mate about April i , continuing till the first or second week in
May. They deposit their eggs singly, ' never in masses,
among leaves and grass in shallow water. When peepers are
in captivity they sometimes lay their eggs in small clusters.

Life history. — Spring peeper tadpoles begin transforming
and coming on land in July when they are little half-inch
frogs. The adults leave the water earlier, scattering into moist
shadowy places, and nothing is heard of them except a few
single notes uttered in autumn, before they disappear into
hibernation.

They will live all winter in damp ferneries or moss-gardens,
climbing the glass sides of the fernery, often singing a few
notes in the evening.

Size. — The male is about an inch long, the female slightly
larger.

Range. — Common, eastern and central North America ; west-
ward to Manitoba; southward to South Carolina and Louis-
iana.

Cricket frog, Acris gryllus. — The cricket frog is a tree frog
which has such small toe pads that it cannot climb trees, but
it can take far higher leaps in air than any crickets can. Its

376

AMPHIBIANS

Fig. 303. — Cricket frog, Acris gryllus.

body is usually less than an inch long, brown or grayish colored
above, with a bright green stripe running down the middle of
the back (Fig. 303). There are dark brown obliquely point-
ed spots on either side of the green stripe and dark brown
cross bands on the hind legs. Its throat and under parts are
creamy white. The color tones vary with the frog's activity;
it may be quite brown and the back stripe more yellowish
than green.

Habits, habitat. — Grass grown, muddy margins of ponds
are the special haunt of the cricket frog. There it forages for
insects through the day, easily captured larvae and pupse or
crickets and grasshoppers, craneflies and other flying insects,
which it can catch b}/ long leaps in air such as few other frogs
can make.

Like whirligig beetles, cricket frogs are easily coaxed out
of hibernation and they become active in every warm spell
of winter.

Breeding habits. — ^They lay their eggs in late April or May,
attaching the single eggs (sometimes small clusters) to sub-
merged grass blades. In that season the males join in a chorus
of sharp chirping calls rapidly repeated and often compared
to the quick striking together of two pebbles.

Size. — Its body is not more than an inch long.

Range. — Eastern North America, southward to Florida and

377

A

FIELD BOOK OF PONDS AND STREAMS

westward to Texas, Kansas, and the Northwest. It has not
been reported north of southern New York and Connecticut.

Fig. 304. — Swamp cricket frog, Pseudacris tri-
seriata. '

Swamp cricket frog, Pseudacris triseriata. — The fullgrown
swamp cricket frog is about one inch long, ashy brown, vary-
ing from light to dark, with three parallel dark stripes which
run the length of its back (Fig. 304). The middle one extends
along the midline of the back and often forks at tha end.
There is a distinct dark spot on each eyelid. The under
parts are yellowish white. Like the cricket frog this is a
tree frog whose toe pads are so small that they are of little \
help in climbing.

Habits. — These frogs live in wet marshes through the sum- '
mer, foraging upon insects, like the cricket frog.

Breeding habits. — 'While searching for Amby stoma jeffer-
sonianum, Wright and Allen {Chorophilus triseriatiis. Bib-
liography, p. 423) found swamp cricket frogs breeding in
ponds in the outskirts of Buffalo about the first of April. The
frogs which they observed were shy and easily silenced but
the captured ones in their bags and pockets soon began to chirp
and started up the chorus again. The egg masses containing
from a couple of dozen to 100 eggs are attached to twigs or
grass stems.

Range. — Locally abundant in early spring, from Oswego,
New York, along Lake Ontario to Utah.

378

AMPHIBIANS

Frogs — RanidcB

Leopard frog, meadow frog, Rana pipiens. — The leopard
frog is green or olive green and bronze above, and on its back,
sides, and legs there are prominent dark spots rimmed with

Fig. 305. — Leopard frog, Rana pipiens.

white. The skin folds or ridges along its back are yellowish
or bronzy; it is pure white beneath (Fig. 305). The pickerel
frog sometimes confused with this one is washed with bright
yellow beneath.

Habitat. — This is one of the most beautiful of frogs, and the
common one of the marshes, pond sides, and cat-tail pools.
It hibernates in the bottom mud of pools and under the plant
litter of brooks where it is often found in winter.

Breeding habits. — The leopard frog choir is the second one
to enter the swamp chorus in spring. By the last of April,
leopard frogs have assembled in the ponds and their low,
guttural croaking can be heard clearly contrasted with the
shrill notes of the peeper. From mid-April to early May it is
easy to observe their croaking, either at night or in the day-
time. The male frogs, lounging half-submerged in the water,
appear to take a long breath, after which they suddenly
inflate the large vocal sac over each shoulder, which swells

379

FIELD BOOK OF PONDS AND STREAMS

Fig. 306. — Head of male leopard frog with his
vocal sacs distended.

larger and larger, as the croak resounds (Fig. 306). When
one of them is singing in chorus it repeats the croak four or
five times, keeping its sacs distended, suddenly collapsing
them as the air is drawn down into the lungs again. Like
other frogs, leopards can croak beneath as well as above the
water. During the breeding season, they are easily captured,
and mating pairs can be collected and kept in jars provided
with enough water for the eggs which are likely to be laid
there within a few hours.

Lije history. — The eggs are laid in masses, attached to
sticks or grasses, and are commonly found in marshes and cat-
tail pools; each egg mass, containing four to five hundred eggs,
is only i or 2 inches across when it is first laid, but the jelly
soon swells until it is 3 to 5 inches thick.

In late July and August recently transformed leopard frogs
populate the margins of the ponds. They are both shy and
agile, and at the least alarm, will leap wildly into the water.
They are long-nosed and slender, brown or green, often with-
out any spots at all. These young leopard frogs soon join
the old ones which have left the water before them and forage
with them through the marsh grass, feeding on grasshoppers
and leaf insects until October frosts begin, when they go into
the streams to hibernate for the winter.

Economic importance. — The leopard frog is the frog of the

380

AMPHIBIANS

laboratories. Thousands of them are used yearly for dis-
section and experimentation in universities, colleges, and high
schools. Although its average weight is not more than two
ounces, the leopard frog is the mainstay of the edible frog
industry. In 1908, 250,000 pounds of frogs' legs were sold
in the United States markets. A firm in the Oneida Lake
region of New York conducting a gross business of $15,000
per year in frogs sold one customer over $1,600 worth of
frogs' legs between June, 1915, and March, 1916. "An expert
can dress between 1,500 and 1,600 frogs per hour, but an
average rate is about 1,000 per hour" (Adams, C, and
Hankinson, T. L.: Trans. Amer. Fish. Soc, Vol. 45:163).

Size. — The body of the male measures about 3 inches; the
female is larger.

Range. — Very common in the whole of eastern and central
North Anaerica.

Fig. 307. — Pickerel frog, Rana palustris.

Pickerel frog, Rana palustris. — 'The pickerel frog resembles
the leopard frog in general shape and color, but is browner ; its
spots are more regular and rectangular than those of the
leopard frog and are not rimmed with white (Fig. 307). The

381

FIELD BOOK OF PONDS AND STREAMS

under part of the body is white in front washed with bright
orange behind and on the hind legs.

Habits, habitat. — Like the leopard, the pickerel frog
hibernates in streams, under stones. Wright trapped many
of them at the mouths of ravines, as they were migrating
downstream to their spring breeding places in the swampy
valley below. Their spring call is similar to that of the
leopard frog, is pitched low, and has a distinct snoring quality.

Breeding habits, life history. — Although pickerel frogs are
. inclined to be shy and solitary at other times, they are gregari-
ous enough during the breeding season, and easy to approach.
They lay their eggs in shallow water attached to submerged
sticks, often several bunches to one stick. The tadpoles
transform in late summer.

Size. — The body is about 2 inches long; the female is a little
larger.

Range. — Eastern North America from the Atlantic to the
Great Plains.

Fig. 308. — ^Eastern wood frog, Rafia sylvatica.

Eastern wood frog, Rana sylvatica. — The upper parts of
the wood frog vary from light fawn color to dark brown; be-
neath it is almost pure white. Its distinctive mark is a prom-
inent dark brown or blackish cheek patch below which a light
line extends along the upper jaw to the shoulder (Fig. 308).

382

AMPHIBIANS

Habits, habitat. — Except during the breeding season wood
frogs wander far away from the water, foraging among the
mosses and fallen leaves of damp woods with which their
colors blend well enough to hide them. They hibernate be-
neath leaves, in stumps, or under logs far away from ponds.

Breeding habits. — Wood frogs come out of hibernation
early, usually by late March. They closely follow the
spring peeper and arrive suddenly in the woodland pools,
generally announcing themselves by a chorus of explosive
clucks. There is a protected leaf-strewn forest pond on
Mount Tom, in Massachusetts, to which they come earlier
than spring peepers do to the ponds of the lower levels. A
great company of them remain in the water from one to three
weeks; after that only a stray lingerer may now and then be
found. During their sojourn in the ponds they sing during
the daytime, and at night, too, if it is warm enough. Even
in the breeding season wood frogs are shy and their clucking
chorus usually ceases as one approaches their pond.

When croaking, the male wood frog sprawls in shallow
water with his head above the surface, or swims about during
the performance. Mating pairs are easily captured with a
water-net, and the females will lay their eggs in captivity.
Their rounded egg masses are attached to submerged sticks
and to branches which dip into the water (PI. ^X). Two or
three masses of wood frog eggs and one or two clusters of
spotted salamander eggs (PI. XX) may be attached to the
same twig.

Life history. — In New England the tadpoles transform
through midsummer, the first ones being out of the water by
the middle of July.

Size. — The body of the male is 2 inches long ; the female is
3 inches.

Range. — Common in the east ; eastern North America from
the Atlantic to the Mississippi River, southward to South
Carolina, northward to Quebec.

383

PI. XX. — Amphibian eggs: i, spotted salamander, Amby'
stoma maculatum; 2, wood frog, Rana sylvatica-, 3, common
toad, Bufo americanus.

Photo, by A. H. Morgan

• jT «

PLATE XX

i

A AMPHIBUNS

Green frog, Rana clamitans.— The green frog's head and
shoulders are bright green, shading to olive or brown at the
end of the body (PI. XXI). It has a lateral skin fold or ridge
on each side of its back, the under parts are white with indis-
tinct dark marblings; in the male the throat is washed with
yellow. Green frogs might be confused with small bullfrogs
except for the lateral folds which are never present in bull-
frogs (PL XXI and Fig. 309).

Habits, habitat. -^Green frogs and bullfrogs live together in
swamps and ponds, but the green frog forages along small
streams not often frequented by the bullfrog. Green frogs
are solitary, only one or two staying in one pool, or in the
bends of the stream bank.

They hibernate in the mud of ponds, often staying in
springs, wedged between stones or sprawled on the bottom
but swimming up into the open water on warm days. A
certain covered spring near South Hadley, Massachusetts, is
a regular winter resort for green frogs.

Breeding habits. —Green frogs swim about through the
ponds very early but they do not begin their low-pitched
croaking until much later, and do not mate until the last of
May. From then until August they mate and lay their eggs,
almost always by night.

Life history.— During June and early July the eggs are
very common and the egg masses are spread out like a film
nearly a foot across, over beds of Char a or other submerged
water plants or in the shallow water near shore where they are
destroyed in great numbers by drying. The water is usually
warm and the eggs often hatch into tadpoles in less than a
week.

Green frog tadpoles which hatch in June do not transform
to frogs until the following spring or early summer.

Size.—Body of the female 5 inches long, the male is smaller.

Range.—Common in eastern and central United States and
southern Canada.

385

PL XXI. — Frogs: from above downward, spring peeper,
Hyla crucifer, dark and light color phases; "tree toad," Hyla
versicolor, light color phase; green frog, Rana clamitans, male
with large and female with smaller ear-drum.

PLATE XXI

AMPHIBIANS

Fig. 309. — Bullfrog, Rana catesbiana.

Bullfrog, Rana catesbiana. — Bullfrogs are green or greenish
brown with white slightly mottled under parts, and yellow
throats. They look like larger editions of the green frog except
that they never have skin folds on each side of the back
(Fig. 309).

Habits, habitat. — Their favorite haunts are in ponds where
the shallows are overgrown with pickerel weed and arrow-
head, well populated with snails and nymphs of dragonflies
and mayflies. They devour great numbers of these as well
as worms, tadpoles, and little frogs of their own or any other
species. Though less common in small streams than large
ones, there are certain little brooks inhabited by burrowing
mayflies from whose banks two or three bullfrogs are never
missing. Bullfrogs are even more aquatic than green frogs
and they never go far away from the water, usually they are
in it. They get all their food there, and they are apt to hiber-
nate in the same pond where they spent their summer.

Breeding habits. — The bullfrog is the last of the frog and
toad procession to come out of hibernation, and it does not
begin croaking in the ponds until nearly June. From then

387

FIELD BOOK OF PONDS AND STREAMS

through midsummer, especially on moist evenings, it repeats
its famous call, "be drowned, better go round," and as boldly
now as in former years it says "jug-o-rum, more rum."
During the breeding season bullfrogs, often a dozen or so
mating pairs, gather in ponds and at night it is comparatively
easy to capture them. They float partly outstretched at
the surface and when the light is flashed on them they ap-
pear paralyzed though their paralysis is far from dependable.
The way to catch them by hand is to seize them very firmly
by both hind legs, for a bullfrog "in the hand" is strong and
apparently much larger than the same one in the pond.

Life history. — ^Bullfrogs usually lay their eggs at night,
during the last of June or in July. The egg mass, a film of
jelly containing 10,000 to 20,000 small eggs, is nearly two
feet across and floats near the surface, anchored and half
hidden by brush or caught on plant stems.

The tadpoles are two years old or more before they trans-
form into frogs, spending two winters, sometimes a third, in
the tadpole stage, finally becoming frogs in late August. All
of the large tadpoles so common in pools in late fall or early
spring are either green frog or bullfrog tadpoles; there are
apt to be many more of the green frogs. But any tadpole
over three and a half inches long is pretty surely a bullfrog;
one year old bullfrog tadpoles seldom show their hind legs.

Size. — Body of the male 7 to 8 inches long, the female the
same.

Range. — North America, east of Rocky Mountains, and
introduced west of the Rockies.

388

CHAPTER XIX

TURTLES AND SNAKES

Found In or Near Water

Turtles

Our native fresh water reptiles are nearly all turtles ( Testu-
dinata). The only snakes which stay consistently by the water
or in it are the brown water snakes which sun themselves
in shallow stream beds or rest on bushes overhanging the
water.

There are many reptiles which live on land but relatively
few in the water, and even these aquatic ones have hardly
any structures or habits which are thoroughly distinctive of
water life. Reptiles are scaly, cold-blooded vertebrates like
the fishes, but fishes breathe by gills while reptiles have lungs
and generally use them. They do not transform as they
grow up like the gilled tadpoles which change to frogs. Newly
hatched turtles have lungs, breathe air, and look like their
parents. All of the fishes either lay their eggs or bring forth
their young in the water, and most amphibians lay their eggs
in it, but among the reptiles, even the turtles, which spend their
whole lives in the water, come out on land to lay their eggs.

Turtles have an upper and a lower bony shell covered by
horny plates, the upper part being known as the carapace
and the lower one as the plastron. From the strongholds of
these shells turtles thrust out their heads, legs, and tails,
those with less shell, like the snapping turtle, having greater
freedom of action but less protection. A turtle's backbone

389

FIELD BOOK OF PONDS AND STREAMS

connects the neck and tail, as it does in any other vertebrate
— fish, cow, or monke}^ — but it is largely hidden beneath the
shell and rigidly joined to it.

Habits, habitat. — Turtles live in quiet ponds and the pro-
tected backwaters of streams. Water snakes also prefer
quiet places but they usually lie in shallow rills seldom visited
by turtles. Turtles have a keen sense of smell under water
as well as in air and they can scent their food at considerable
distances.

Food. — Turtles and snakes are both generally carnivorous.
Turtles feed upon a miscellaneous assortment of animal food,
dead and alive — small fish, tadpoles, snails, and insects. To
this diet the wood and the painted turtles add water plants
and seeds (Fig. 21).

Breeding habits. — Male and female turtles are sometimes
but not always distinguishable. The tail of the male may be
longer than that of the female; the lower shell or plastron
is apt to be slightly convex in the female and concave in the
male. In some turtles there are differences in the lengths of
the shells, the male wood turtle having a shorter plastron
than the female. When turtles are dissected there is no
doubt of the sex, for the ovaries of the female are large and
conspicuous, with yellow, yolked eggs like those of birds.

Turtles which frequent the water usually mate there,
but this includes the wood turtle which outside of its breeding
period seldom goes into the water. When mating, the male
wood turtle grasps the shell of the female, holding to it by his
claws, head, and tail. The female does all of the swimming
but both animals twist and turn, the female often struggling
to get to the surface for air. While this struggle is going on
the male discharges large numbers of sperm cells into the
reproductive passages of the female. These find their way
up the oviducts and meet the eggs as they come down the
tubes. Turtle eggs look like bird eggs except that the shells
are always clear white or pinkish. Some species, such as the

390

TURTLES AND SNAKES

painted turtle, have soft shelled eggs ; others, like the snapper,
have hard shelled ones. They are hidden in soil or rotting
wood and leaves, and usually take a long time to incubate,
about eighty days for those of the spotted turtle.

Life history. — Newly hatched frogs are fishlike and young
flies look like worms, but just-hatched turtles are small edi-
tions of their parents. They have lungs and breathe air;
they walk on the same feet which they use in their old age,
going through no marked transformation as they grow up.
Although fresh water turtles, like land and marine ones, live
to a considerable age, their bony shells are never shed, but
each plate or shield grows larger and thicker until it reaches
adult size. The painted turtle, Chrysemys picta, sheds the
outer horny transparent layer of its shell periodically and for
some time afterwards its colors appear very bright. If a good
sized piece of a turtle's shell is broken or crushed, the broken
part will slough off, new shell will grow, and after several
months only a scar will mark the injury.

Snapping Turtles — Chelydridce

Snapping turtle, Chelydra serpentina. — The snapper is a
water turtle but there are more than equal chances that it
will be found on land, for it explores the streamsides and ad-
joining fields in May and June when humanity is also out
walking. It is the largest of our fresh water turtles, yet on
land it is a swift walker, and can lunge and jump completely
off the ground. Snapping turtles may weigh 40 pounds or
more but they commonly weigh 25 or 30 pounds and are over
2 feet long. Their shells are comparatively small, allowing
free action of the legs and the long neck and head, the latter
so large that it can be pulled only part way into the shell
(Fig. 310). On the upper side of the tail there is a row of
low tubercles forming a crest like the one on an alligator's
tail; in very young snappers there are three such elevations

391

FIELD BOOK OF PONDS AND STREAMS

Fig. 310. — Snapping turtle, Chelydra serpentina;
I, from above; 2, ventral side showing the small
plastron which allows free action of the legs and
head.

along the middle of the carapace but these do not show very
much in older turtles.

Habits, habitat. — Except around the egg-laying season
snapping turtles stay in ponds and meandering marsh
streams, patrolling the bottom or hanging relaxed in the water

392

TURTLES AND SNAKES

with only their nostrils out of it. Although they appear
sluggish and awkward, they can thrust forth their heads and
snap their strong hooked jaws with lightning rapidity. They
are quick enough to capture swift moving animals — fish,
frogs and flies — but they will also devour anything available
— insects, snails, crayfishes, mice, small birds, and occasionally
dead animals. They very commonly catch ducklings by the
legs when they are swimming on meadow ponds, and they
sometimes attack full sized ducks. When frightened or
maltreated, most turtles retreat into their shells, but snappers
protect themselves by snapping and biting, doing so at the
slightest excuse. When snappers are caught, they should be
carried by the tail, head downward, so that they cannot spring
or stretch their necks far enough to bite.

Breeding habits.— The female snapper takes her spiing
rambles on land, in search of a nesting place. She selects
soft, damp earth, scoops a hole in it, digging with her hind
legs till her body is nearly hidden, then she lays twenty ot
more round hard-shelled eggs about an inch in diameter. A
vivid story of the egg-laying of the snapping-turtle is told
by Dallas Lore Sharp in the chapter "Turtle Eggs for Agassiz"
in his volume called "The Face of the Fields. " The enemies
of the snapper are numbered chiefly among the animals which
eat its eggs — mink, weasels, and skunks.

Size. — Length of fullgrown turtle, 2 feet or more; very large
ones are nearly 3 feet long and weigh about fifty pounds.

Range. — Common, United States east of the Rocky Moun-
tains.

Box Turtles — Kinosternidce

Musk turtle, stinkpot, Stemotherus odoratus. — Like the
snapper the musk turtle lives in the water, coming on land
only to lay its eggs. It is one of our smallest turtles, and the
whole animal is only 4 or 5 inches long. Its carapace is
highly arched, smooth, brown; the plastron is yellowish,

393

FIELD BOOK OF PONDS AND STREAMS

small, cross- shaped, and notched behind (PI. XXII). Two
narrow yellow stripes extend along each side of the head and
neck, one above and one below the eye. The male has a
longer and stronger tail than the female and a "patch of
rough scales in the bend between the thigh and the leg."
Musk turtles give off a penetrating odor of musk from the
musk glands near the bases of the hind legs and near the
axils of the forelegs. Their dispositions are consistently
vicious. They stretch out their heads very slowly before
snapping and the expression of the whole performance is
surly and premeditated.

Habits, habitat. — In color, musk turtles match the muddy
bottoms of the ponds and sluggish streams where they live,
which partly accounts for their being so little known (PL
XXII). They are bottom foragers that crawl over the mud,
stretching their necks out very slowly before snapping at their
prey — small fish, worms, insects, or tadpoles. Although
having lungs like all other turtles, they are able to stay below
the surface of water a very long time ; Ditmars kept them for
weeks in tanks where they could not get to the air. "Digging
in" is about the only activity of musk turtles when they are
in captivity ; one kept in the Mount Holyoke Zoology Labora-
tory through a winter and spring would burrow into the dirt
as often as it was pulled out. After a long sojourn in the dirt
it was thin and shrunken but would appear greatly refreshed
as soon as it had been "soaked up" in water.

Breeding habits. — Its 3 to 7 smooth, white, elliptical eggs
are laid in late June, in rotting stumps and logs or clumps of
reeds. The newly hatched young are about half an inch long.

Size. — The average length of the whole animal is 5 to 6
inches.

Range. — Southern Canada to Florida,'westward to Missouri
and Texas.

Mud turtle, Kinosternum subrubrum. — Although many
persons know all pond turtles as "mud turtles," only this

394

TURTLES AND SNAKES

Fig. 311. — Mud turtle, Kinosternum subruhrum;
I, dorsal and 2, ventral view showing-^the plastron
with hinged ends which can be drawn up against
the carapace.

one small species is the real mud turtle. It is not found north
of New York and even within its range it is far from common.
Its upper shell or carapace is plain dull brown and the broad
oval plastron is yellowish, the two ends of it being hinged so
that they can be drawn up closely against the carapace, the
trait which gives this family the name box turtles (Fig. 311).

395

PI. XXII. — Musk turtle, Sternotherus , odoratus, a box
turtle whose plastron is only slightly flexible at the ends, one
of our smallest turtles: i, dorsal and 2, ventral view.

PLATE XXII

TURTLES AND SNAKES

The head is brown with yellow fleckings along the sides of the
neck but without the distinct yellow lines which mark the
musk turtle's head (PI. XXII). The male has a longer tail
than the female and there is a horny point at the end of it.

Habits, habitat. — ^The mud turtle lives in muddy bottoms
similar to the haunts of the musk turtle but it is less fond of
the water. It also has a better disposition. Just after it
first appears from hibernation it is coated with dried mud
paste from its burrow, usually made in moist earth only fifty
yards or so distant from a marsh. At the end of hibernation
it is in the same shrunken condition as the musk turtle. Its
habit of absorbing water at this time is described by Wetmore
and Harper in their account of its hibernation: "The
turtle that we found was taken home and placed in a basin of
water. For several minutes it made no movement save to
emit a series of bubbles from its nostrils, or to close and open
an eye. Then it proceeded to extend and retract its neck
slowly. The jaws were opened and closed slowly. In a
short time movement of the jaws ceased, but the turtle con-
tinued to draw water into the mouth and then expel it. . . .
In a few moments the turtle became more alert and swam
and walked about, thrusting its head to the surface."

Breeding habits. — In the Okefinokee Swamp in Georgia,
Wright found a nest of the mud turtle in rotten wood, con-
taining three elliptical eggs buried about three inches below
the surface.

Size. — The carapace of adults is about 4 inches long.

Range. — Probably not common anywhere. New York,
southward to the Gulf of Mexico and westward to the Missis-
sippi Valley.

Pond and Land Turtles — Testudinidce

Painted turtle, Chrysemys picta. — In New England the
painted turtle is the most common of all the fresh water

397

FIELD BOOK OF PONDS AND STREAMS

turtles. Its only rivals are the spotted turtles which bask
with it in the sun, along the same pond banks and floating
logs (PL XXIII).

Its flattened carapace is very smooth, and the plates are
olive brown with borders of pale yellow; these form a narrow
light band across the back between the first and second rows
of plates. The small marginal plates are red with black and
yellow markings, most of the color being on the underside;
the plastron is light yellow. There are two bright yellow
streaks behind each eye, and stripes of yellow which give
place to scarlet on the throat, legs, and tail. Its whole colora-
tion suggests a dark-painted vehicle with gay running gear.

Habits, habitat. — The favorite haunts of painted turtles
are the partly overgrown ponds where there are large popula-
tions of small water animals (Fig. 21). They swim in and
out among the plants, displaying their scarlet rims at each
leisurely dip of their bodies, or they climb out of the water
to bask upon logs, only to slide back again at the least alarm.
They eat almost anything which they find under water but
they seem quite unable to swallow if they are out of it. By
examining the stomachs of painted turtles, Surface found that
their diet included algae, grasses, moss, insects, little mollusks,
and pieces of larger animals evidently eaten when half decayed.
In October they begin digging into the muddy pond bottoms
for their winter hibernation.

Breeding habits. — They lay their elliptical eggs between
the middle and last of June, always in late afternoon or even-
ing. The turtle selects a nest site in soil not far distant from
water, digs a hole with her hind feet, and lays the four to
eight or more pinkish eggs. Without turning around she
pushes each one down into the hole with her hind feet, cover-
ing them so well that she leaves little or no trace of her work.

Size. — Length of adult carapace about 6 to 8 inches.

Range. — Eastern North America, northward to southern
Canada, southward to Georgia. West of the Alleghanies it

398

TURTLES AND SNAKES

is wholly replaced by the closely related western painted
turtle, Chrysemys marginata.

Spotted turtle, Clemmys guttata. — Spotted turtles are the
yellow polka-dotted turtles which sun themselves in com-
panies on floating logs or islands of reeds and grasses. They
climb up onto a log, crowding and piling one upon another,
but the least alarm sends them all tumbling back into the
water together. Such basking companies are often made up of
both painted and spotted turtles. The spotted turtle has a
smooth, low carapace, black scattered over with yellow or
orange spots (PI. XXIII); the middle of its plastron is dull
yellow and on the underside the edges of the carapace are
marked with yellow. The male has a tail nearly twice as
long as that of the female.

Hahits, habitat. — It seems to take all its food under water,
yet it travels considerable distances overland. Spotted
turtles are very good natured, and they thrive in captivity
on a diet of chopped raw meat. This is the species which
Yerkes used for studies of habit-formation and found that it
does remarkably little aimless wandering, possessing keen
senses of smell and sight and appearing to learn from experi-
ence. It eats plant stems and leaves as well as insects and
crustaceans.

Breeding hahits. — It lays its elliptical eggs in the same
season as the painted turtle, in late afternoon or evening, from
the middle to the last of June. They are a long time incubat-
ing; Babcock buried some of them in sand on June i6 and
they did not hatch until September 6. At that time the
young turtle had a carapace about one inch long.

Size. — The carapace of the male is about 5 inches long, that
of the female an inch shorter.

Range. — Through the eastern states from Maine to Florida
and westward to Indiana and Michigan.

Wood turtle, sculptured turtle, Clemmys insculpta. — Wood
turtles are the familiar "carved" or "sculptured" turtles

399

PL XXTII. — Two common pond turtles: i, spotted turtle,
Clemmys guttata; 2, painted turtle, Chrysemys picta.

PLATE XXIII

;si:^sgars«"*j'*y '

! v)

TURTLES AND SNAKES

Fig. 312. Wood turtle, Clemmys insculpta: 1,
dorsal view showing the sculptured carapace; 2,
ventral side.

usually found in fields and open woodlands. They are so
called because of the roughly sculptured concentric ridges on
each plate of the carapace and these markings alone are
enough to identify them (Fig. 312). Their heads and feet
are rusty black and brown and all of the other soft parts are
dull salmon red. These colors and the gray brown of the
carapace hide them in backgrounds of dead grasses and fallen
leaves.

401

FIELD BOOK OF PONDS AND STREAMS

Habits, habitat. — During late spring and summer wood
turtles wander through pastures and woodland and over
upland fields far from the water. The food they gather along
the way is not very different from that of the ground-feeding
birds — blackberries, partridge berries, mushrooms — but in
the water they live on the regular turtle diet of small aquatic
animals. They hibernate in muddy stream bottoms.

Breeding habits. — Wood turtles always mate in the water
and as readily in tanks or artificial pools as in their native
ponds. The usual season is through May and June but
Wright found a pair mating in a woodland stream on the fi.rst
of October. Ordinarily the wood turtle lays her eggs in June,
depositing about a dozen in a hollow of the ground, and after
covering them, leaves them to hatch as other turtles do.

Size. — Length about 8 inches.

Range. — From Canada southward through New Jersey and
Pennsylvania to Maryland and westward to Michigan and
Wisconsin.

Soft-shelled Turtles — Triony chides

Spiny soft-shelled turtle, Amyda spinifera. — There is no
mistaking the soft- shelled turtles. In place of the bony shells
of most turtles, they have a carapace and a plastron which
can be bent between the fingers like rubber. They are
thoroughly aquatic animals, swift swimmers with broadly
webbed feet (Fig. 313).

The spiny soft-shelled turtle is flat bodied with a yellowish
brown carapace and pure white plastron and under parts.
The young turtles, 3 or 4 inches long, with polka-dots of black
on the carapace, are often sold in the pet shops and by
aquarium dealers. The soft-shell bencjs its long neck in an
S-shaped curve; its narrow head is prolonged into a leathery
snout with the nostrils at the tip. It usually floats just
below the surface of the water, with its nostrils thrust out
into the air.

402

TURTLES AND SNAKES

Fig. 313. — Spiny soft-shelled turtle, Amyda sptn-
ifera, which has a leathery or soft shell: i, from
above; 2, ventral view showing the small soft plas-
tron and webbed feet.

403

FIELD BOOK OF PONDS AND STREAMS

Habits, habitat. — This turtle lives in shallow, muddy-
bottomed water, never leaving it except to lay its eggs. It is
a scavenger as well as a voracious feeder upon aquatic animals,
even good-sized mussels. It thrives in an aquarium, but
lies much of the time half buried in the sand. Although
this turtle has lungs and no gills, it can stay under water a
long time, securing oxygen from the water which it takes
into its mouth. Its mouth and throat have a thin lining
richly supplied with fine blood-vessels, and an exchange of
gases, oxygen and carbon dioxide, takes place just as it does
in the gills of fishes.

Breeding habits. — Clumsy and awkward as these turtles
are on land, they persevere in crawling out of the water to
lay several white, round eggs in the moist sand of the shore.

Size. — Length about 14 inches.

Range. — Along the Mississippi River and its tributaries
eastward into Pennsylvania and New York, northward to
Lake Champlain.

Fig. 314. — Northern water snake, Natrix sipe-
don, subspecies sipedon.

404

TURTLES AND SNAKES

Colubrine or Harmless Snakes — Coluhridce

Northern water snake, "moccasin," banded water snake,
Natrix sipedon, subspecies sipedon. — This common water
snake of the northern states lives in sunny hollows watered
by little streams, generally lying partly on the bank and partly
across the stream bed. Sometimes it is found on the borders
of larger streams and ponds.

It is a heavily built snake, dingy dark brown, sometimes
reddish, and of morose appearance; its undersides are
spotted with reddish and black. In young snakes and
those which have recently shed their skins, the back is crossed
by broad brown bands separated by narrower bands of light
brown; on the sides the dark bands taper and the light ones
become broader (Fig. 314).

Habits, habitat. — One snake or a group of two or three often
basks in the sunshine, hanging from bushes over the water,
dropping into it when disturbed or slipping in to capture fish
or frogs. In warm days of early March water snakes begin
sunning themselves along small streams. They are cold
then and move slowly, even allowing themselves to be picked
up without protest, but when they are brought into the
warmth of a house they soon become agile enough to display
their natural ugliness of disposition. They will strike vicious-
ly at anything which comes near them, and although they are
not poisonous they should be kept in a securely screened box.
Although this snake is sometimes called "water moccasin"
it is not related to the poisonous true water moccasin or
"cotton mouth" of the south.

Food. — -Water snakes live very largely upon fish, frogs,
toads and water insects but they do not neglect the meadow
mice and shrews.

Breeding habits. — In the latter part of August or early in
September they give birth to living young, the average num-

405

FIELD BOOK OF PONDS AND STREAMS

ber being about two dozen to a litter. However, a litter of
forty-four has been observed by Ditmars.

Size. — Fullgrown adults are 2 K to 4 feet long and have a
girth of about 2 inches; the average length is 3 feet or less.

Range. — From Maine and southern Canada to North Caro-
lina and westward to Kansas and Wisconsin. Common in
New England and the Middle States.

406

BIBLIOGRAPHY

GENERAL REFERENCES

Carpenter, K. E. 1928. Life in Inland Waters. Mac-
millan Co.

Chapman, R. N. 1925. Animal Ecology. Burgess-Brooke,
Inc., Minneapolis. Contains extensive bibliographies
which include many technical papers.

Copeia. 1913. A magazine containing notes on fish, am-
phibians, and water reptiles. Pub. by Kingsbury Box and
Printing Co., Northampton, Mass.

Jordan, D. S. 1929. Manual of the Vertebrate Animals of
the Northeastern United States. 13th ed. World Book
Co., Yonkers, N. Y.

Needham, J. G., and Lloyd, J. T. 1916. Life of Iijland
Waters. Comstock Pub. Co., Ithaca, N. Y.

Needham, J. G., and Needham, P. R. 1927. A Guide to the
Study of Fresh-water Biology. With Special Reference
to Aquatic Insects and other Invertebrate Animals.
The Amer. Viewpoint Soc, 13 Astor Place, New York,
and Albany. Includes keys with figures of each form
mentioned and suggestions for studies of aquatic com-
munities.

Pratt, H. S. 1923. Manual of the Common Invertebrate
Animals. Exclusive of Insects. A. C. McClurg & Co.,
Chicago.

1923 a. Manual of Land and Fresh Water Vertebrates
of the United vStates. P. Blakiston's Son & Co., Phila.

Shelf ord, V. E. 19 13. Animal Communities in Temperate
America. Univ. of Chicago Press. ^ ,

■ 407

BIBLIOGRAPHY

Ward, H. B., and Whipple, G. C. 191 8. Fresh- Water
Biology. John Wiley & Sons. The most inclusive
American fresh water biology. Illustrated keys and
descriptions.

Whipple, S. C. 1927. The Microscopy of Drinking Water.
(Revised by Fair, G. M., and Whipple, M. C.) John
Wiley & Sons.

CHAPTER II

LIFE IN PONDS AND STREAMS

General References: Needham and Lloyd, 1916; Whipple, 1927.
Forbes, S. A. 1925. The Lake as a Microcosm. Bull.

IlHnois Nat. Hist. Survey, Vol. 15, Art. 9, Urbana.
Needham, J. G. 1922. A Biological Reconnaissance of Lake

George. Biol. Survey of Lake George, N. Y. vState of

N. Y., Conservation Com., Albany.

Seasonal succession of life.

General References: Shelf ord, 1913, Animal Communities in
Temperate America, see successions in lakes and ponds.

Allee, W. C. 19 11. Seasonal Succession in Old Forest
Ponds. Trans. Illmois State Acad. Sci., Vol. 4: 126-131.

Shelford, V. E. 1918. Physiological Problems in the Life-
Histories of Animals, with Particular Reference to Their
Seasonal Occurrence. Amer. Nat., Vol. 52: 129-154.
1919. Nature's Mobilization. Nat. Hist., Vol. 19: 205-
210.

1929. Laboratory and Field Ecology. Williams 8c
Wilkins Co., Baltimore.

CHAPTER III

COLLECTING AND PRESERVING WATER ANIMALS

Aquatic Life. A magazine devoted to aquarium life. It con-
tains names and addresses of supply dealers. Roth, A.
Baltimore.

408

BIBLIOGRAPHY

Bishop, S. C. 1927. The Amphibians and Reptiles of
Allegheny State Park. N. Y. State Mus., Handbook,
No. 3, Albany.

Casino, S. E. The Naturalists' Directory. Salem, Mass.
Names, addresses and special subjects of study of pro-
fessional and amateur naturalists of the United States,
Canada, and other countries, including South America.
(Addresses of collectors and some dealers; biennial.)

Eggeling, O., and Ehrenberg, F. 19 12. The Freshwater
Aquarium and Its Inhabitants. Henry Holt.

Gordon, M. 1927. Keeping Native Fishes in Aquaria.
Cornell Rural School Leaflet, Vol. 21, No. i, Ithaca, N. Y.

Lutz, F. E. 1927. How to Collect and Preserve Insects.
Amer. Mus, Nat. Hist., Guide Leaflet Series, No. 39,
New York.

Smith, E. 1902. The Home Aquarium and How to Care
for It. E. P. Button & Co.

CHAPTER IV

SIMPLER PLANTS AND ANIMALS

General References: Needham and Needham, 1927; Ward

and Whipple, 191 8; Whipple, 1927; or Chapter V,//i£/ter

plants, Kemer and Oliver, 1895.
Brown, H. E. 1908. Algal Periodicity in Ponds and Streams.

Bull. Torrey Botanical Club, Vol. 35: 223-248.
Conn, H. W. 1905. A Preliminary Report -on the Protozoa

of the Fresh Waters of Connecticut. Conn. State Geo).

and Nat. Hist. Survey, Bull. No. 2, Hartford.
Hausman, L. A. 191 7. Observations on the Ecology of the

Protozoa. Amer. Nat., Vol. 51: 157-172.
Hylander, C. J. 1928. The Algae of Connecticut. Conn.

State Geol. and Nat. Hist. Survey, Bull. No. 42, Hartford.
Kahn, M. C. 1920. Microscopical Trouble-makers in the

Water Supply. Nat. Hist., Vol. 20: 83-90.

409

BIBLIOGRAPHY

Mann, A. 1921. The Dependence of the Fishes on the

Diatoms. Ecology, Vol. 2: 79-83.
Matheson, R., and Hinman, E. H. 1928. Chara fragilis

and Mosquito Development. Amer. Jour. Hygien'e,

Vol. 8 : 279-292.
Piatt, E. L. 191 5. The Population of the " Blanket-Algae "

of Fresh-water Pools. Amer. Nat., Vol. 49: 752-762.
Smith, G. M. 1924. Ecology of the Plankton [Algae in the

Palisades Interstate Park, Including the Relation of

Control Methods to Fish Culture. Roosevelt Wild

Life Bull., Vol. 2, No. 2, Syracuse Univ.
Stokes, A. C. 19 1 8. Aquatic Microscopy for Beginners.

4th ed. John Wiley & Sons (out of print).

CHAPTER V

HIGHER PLANTS

General References: Ward and Whipple, 191 8.

Arber, A. 1920. Water Plants. Cambridge Univ. Press.

Britton, N. L., and Brown, A. 19 13. Illustrated Flora of the
Northern United States, Canada, and the British Posses-
sions. 2nd ed. Charles Scribner's Sons.

Claassen, P. W. 1921. Typha Insects; Their Ecological Rela-
tionships. Cornell Univ. Agri. Exp. Sta., Mem. 47,
Ithaca, N. Y.

Coulter, J. M. 1904. Plants, a Text-book of Botany. 3rd
ed. D. Appleton & Co.

Grout, A. J. 1905. Mosses with a Hand-lens. 2nd ed.
O. T. Louis Co., New York.

Hegner, R. W. 1926. The Interrelations of Protozoa and
the Utricles of Utricularia. Biol. Bull., Vol. 50: 239-270.
1926 a. The Protozoa of the Pitcher Plant, Sarracenia
purpurea. Biol. Bull., Vol. 50: 271-276.

Kemer, A., and Oliver, F. W. 1895. The Natural History
of Plants, Their Forms, Growth, Reproduction, and
Distribution. 4 vols. Holt & Co.

410

BIBLIOGRAPHY

1904. The Natural History of Plants. 2 vols. Gresham

Pub. Co., London.
Miner, R. W. 1928. A Drama of the Microscope. The

New Rotifer Group. Nat. Hist., Vol. 2S: 500-514.
Moore, E. 19 15. The Potamogetons in Relation to Pond

Culture. Bull. Bur. Fish., Doc. 815, Vol. 33: 251-291.
Pearse, A. S., and Terrell, C. B. 1920. Aquatic Preserves.

Nat. Hist., Vol. 20: 103-106.
Pond, R. H. 1905. The Biological Relation of Aquatic

Plants to the Substratum. Rep. U. S. Com. of Fish and

Fisheries for 1903: 483-526.
Power, S. 1903. The Possibilities of Peat. Outlook, Vol.

73: 172-175.

CHAPTER VI

SPONGES

General References: Ward and Whipple, 19 18, Chap. 10, Potts,

E., Sponges (Porifera).
McNair, G. T. 1923. Motor Reactions of the Fresh- Water

vSponge Ephydatia fluviatilis. Biol. Bull., Vol. 44:

153-166.
Morgan, A. H. 1929. Fresh- Water Sponges in Winter.

Sci. Mo., Vol. 28: 152-155.
Potts, E. 1887, Fresh- water Sponges; a monograph. Proc.

Acad. Nat. Sci., Phila., Vol. 39: 158-279.
Smith, F. 192 1. Distribution of the Fresh-Water Sponges

of North America. Bull. Illinois Nat. Hist. Survey, Vol.

14: 9-22, Urbana.

CHAPTER VII

THE HYDRAS, FRESH WATER JELLYFISHES

General References: Ward and Whipple, 1918, Chap.' II,
Smith, F., Hydra and Other Fresh- Water Hydrozoa;
Pratt, 1923.

411

A

BIBLIOGRAPHY

Clemens, W. A. 1922. Hydra in Lake Erie. Science, Vol.

55, No. 1426: 445.
Gudger, E. W. 1927. Hydras as Enemies of Young Fishes.

Nat. Hist., Vol. 27: 270-274.
Hickson, S. J. 1925. Hydra and the Tadpoles. Nature,

Vol. 115: 802.
Scourfield, D. J. 1904. Hydra and the Surface-Film of

Water. Jour. Quekett Micr. Club, Nov. 1904.
Welsh, P. S., and Loomis, H. A. 1924. A Limnological

Study of Hydra oligactis in Douglas Lake, Mich. Trans.

Amer. Micr. Soc, Vol. 43: 203-235.

CHAPTER Vni

FREE-LIVING FLATWORMS

General References: Ward and Whipple, 191 8; Chap. 12,
Stringer, C. E., Free-living Flatworms; Pratt, 1923.

Bardeen, C. R. 1901. On the Physiology of the Planaria
maculata with Especial Reference to the Phenomena of
Regeneration. Amer. Jour. Phys., Vol. 5: 1-53.

Carpenter, K. 1928. On the Tropisms of Some Freshwater
Planarians. Brit. Jour. Exp. Biol, Vol. 5, No. 3: 196-
203.

Pearl, R. 1902. The Movements and Reactions of Fresh-
water Planarians. Quart. Jour. Micr. Sci., Vol. 46: 509-

714-
Walter, H. E. 1907. The Reactions of Planarians to Light.

Jour. Exp. Zool., Vol. 5: 35-162.

CHAPTER IX

WHEEL ANIMALCULES (Rotifera)

General References: Needham and Needham, 1927; Ward
and Whipple, 19 18, Chap. 17, Jennings, H. S., Wheel,
• Animalcules.
Harring, H. K. 1913. Synopsis of the Rotatoria. U. S.
Nat. Mus., Bull. No. 81.

412

BIBLIOGRAPHY

Jennings, H. S. 1900. Rotatoria of the United States with

Special Reference to Those of the Great Lakes. Bull.

U. S. Fish Com. for 1899: 67-104.

1901. Synopses of North American Invertebrates. XVII.

The Rotatoria. Amer. Nat., Vol. 35: 725-777.
Mueller, H.O. 1925. The Rotifer Group. Nat. Hist. , Vol.

25: 223-232.
Myers, F. J. 1925. What is a Rotifer? Nat. Hist., Vol.

25:211-223.

CHAPTER X
MOSS ANIMALCULES (Bryozoa)

General References: Pratt, 1923; Ward and Whipple, 1918,

Chap. 28, Davenport, C. B., Moss Animalcules (Bryozoa).
Davenport, C. B. 1890. Cristatella: The Origin and

Development of the Individual in the Colony. Bull.

Mus. Comp. Zool., Harvard College, Vol. 20: 101-152.

1904. Report on the Fresh- water Br3^ozoa of the United

States. Proc. U. S. Nat. Mus., Vol. 27: 211-221.
Landacre, F. 1901. Sponges and Bryozoa of Sandusky

Bay. Ohio Nat., Vol. i: 96-97.

CHAPTER XI

THREADWORMS (Nematodes) and bristleworms

(Oligochstes)

General References: Pratt, 1923; Ward and Whipple, 191 8,

Chap. 19, Smith, F., Aquatic Earthworms and other

Bristle-bearing Worms.
Darwin, C. 1900. Vegetable Mould and Earthworms. D.

Appleton & Co.
Galloway, T. W. 191 1. The Common Fresh- water Oligo-

chaeta of the United States. Trans. Amer. Micr. Soc,

Vol. 30: 285-317.

^13

BIBLIOGRAPHY

May, H. G. 19 19. Contributions to the Life Histories of

Gordius robustus Leidy and Paragordius varius Leidy.

Illinois Biol. Monographs, Vol. 5, No. 2.
Montgomery, T. H., Jr. 1899. Synopses of North American

Invertebrates. II. Gordiacea (Hairworms). Amer. Nat.,

Vol. 33: 647-652.
Smith, F. 1900. Notes on North American Oligochaeta.

Bull. Illinois State Lab. Nat. Hist., Vol. 5: 441-478,

Urbana. Also same, Vol. 7: 45-51, 1905.
Walton, L. B. 1906. Naididae of Cedar Point, Ohio. Amer.

Nat., Vol. 40: 683-706.
Welch, P. S. 19 1 4. Studies on the Enchytrasidae of North

America. Bull. Illinois State Lab. Nat. Hist., Vol. 10:

123-212, Urbana.

CHAPTER XII

LEECHES

General References: Pratt, 1923; Ward and Whipple, 1918,
Chap. 20, Moore, J. P., Leeches.

Moore, J. P. 1901. The Hirudinea of Illinois. Bull. Ill-
inois State Lab. Nat. Hist., Vol. 5: 479-546, Urbana.
1923. The Control of Blood-sucking Leeches with an
account of the Leeches in the Palisades Interstate Park.
Roosevelt Wild Life Bull., Vol. 2, No. i, Syracuse Univ.

Nachtrieb, H. F., Hemingway, E. E., and Moore, J. P. 19 12.
Report on the Leeches of Minnesota. Geol. and Nat.
Hist. Survey of Minn., Zool. Series, No. 5; Part III,
Classification of the Leeches of Minnesota, by J. P.
Moore.

CHAPTER XIII

CRUSTACEA

Andrews, E. A. 1904. Breeding Habits of Crayfish. Amer.

Nat., Vol. 38:165-206.
Caiman, W. T. 191 1. The Life of Crustacea. Macmillan

Co.

414

BIBLIOGRAPHY

Embody, G. C. 19 12. Distribution, Food, and Reproduc-
tive Capacity of Some Fresh- water Amphipods . Internat .
Revue der gesamten Hydrobiologie und Hydrographie.
Biol. Suppl. No. 3.

19 1 4. Crustacea. A Key to the Common Genera
Occurring in the Fresh Waters of the Eastern United
States. Cornell Univ., Ithaca, N. Y.

Forbes, E. B. 1897. A Contribution to a Knowledge of
North American Fresh-Water Cyclopidae. Bull. Illinois
State Lab. Nat. Hist., Vol. 5: 27-82, Urbana.

Harris, J. A. 1903. An Ecological Catalogue of the Cray-
fishes Belonging to the Genus Cambarus. Kans. Univ.
Sci. Bull., Vol. 2: 51-187.

Hay, O. P., and Hay, W. P. 1889. A Contribution to the
Knowledge of the Genus Branchipus. Amer. Nat.,
Vol. 23: 91-95-

Hay, W. P. 1896. The Crawfishes of the State of Indiana.
Rep. Ind. Geol. Survey, Vol. 20: 475-506.

Pearse, A. S. 1910. The Crawfishes of Michigan. Mich.
State Biol. Survey, Vol. i : 9-22.

Scourfield, D. J. 1896. Entomostraca and the Surface
Film of Water. Jour. Linnean Soc, Zool., Vol. 25: 1-9.
1900. Note on Scapholeberis mucronatus and the Surface
Film of Water. Jour. Quekett Micr. Club, Series 2, Vol.
7: 309-312.

Shantz, H. L. 1905. Notes on the North American Species
of Branchinecta and Their Habits. Biol. Bull., Vol. 9:
249-264.

Turner, C. L. 1926. Crayfishes of Ohio, Ohio State Univ.
Bull, Vol. 30.

CHAPTER XIV

WATER-MITES (Hydrachnida)

General References: Ward and Whipple, 191 8, Chap. 26,
Wolcott, R. H., Water-mites.

415

BIBLIOGRAPHY

Marshall, R. 1908. The Arrhenuri of the United States.
Trans. Amer. Micr. Soc, Vol. 28: 85-140.

Wolcott, R. H. 1905. A Review of the Genera of the Water-
mites. Trans. Amer. Micr. Soc, Vol. 26: 161-243.

CHAPTER XV

AQUATIC INSECTS

General References:

Alexander, C. P. 1925. An Entomological Survey of the
Salt Fork of the Vermilion River in 192 1, with a Biblio-
graphy of Aquatic Insects. Bull. Illinois Nat. Hist.
Sur\'ey, Vol. 15, No. 8, Urbana, Excellent bibliography
arranged by orders.

Comstock, J. H. 1924. An Introduction to Entomology.
Comstock Pub. Co., Ithaca, N. Y.

Leonard, M. D. (editor). 1926. A List of the Insects of
New York. Cornell Univ. Agri. Exp. Sta., Mem. loi,
Ithaca, N. Y.

Lutz, F. E. 1 92 1. Field Book of Insects. G. P. Putnam's
Sons.

Miall, L. C. 1912. The Natural History of Aquatic Insects.
Macmillan Co.

Needham, J. G., and Lloyd, J. T. 1916. The Life of Inland
Waters. Comstock Pub. Co., Ithaca, N. Y.

Needham, J. G., and Needham, P. R. 1927. A Guide to the
Study of Fresh-water Biology. With Special Reference
to Aquatic Insects and other Invertebrate Animals. The
Amer. Viewpoint Soc, 13 Astor Place, New York, and
Albany. Includes keys with figures of each form men-
tioned and suggestions for studies of aquatic communi-
ties.

Needham, J. G. 1928, Elementary Lessons on Insects.
C. C. Thomas, Springfield, 111.

Ward, H. B., and Whipple, G. C. 191 8. Fresh- Water
Biology. John Wiley & Sons. Includes keys.

416

BIBLIOGRAPHY

Collembola.

Folsom, J. W. 19 1 6. North American CoUembolous Insects
of the Sub-famiHes Achorutinae, Neanurinae, and Podur-
inae. Proc. U. S. Nat. Mus., Vol. 50: 477-525-

Plecoptera.

Needham, J. G. 1901. Plecoptera; in Aquatic Insects in

the Adirondacks. N. Y. State Mus., Bull., Vol. 47: 412-

418, Albany.
Needham, J. G., and Claassen, P. W. 1925. Monograph:

Plecoptera or Stoneflies of America north of Mexico.

LaFayette, Indiana.
Smith, L. W. 191 3. The Biology of Perla immarginata

Say. Ann. Ent. Soc. Amer., Vol. 6: 203-211.
Wu, C. F. 1923. Morphology, Anatomy and Ethology of

Nemoura. Lloyd Library, Bull., Ent. Series No. 3:

1-8 1. Cincinnati, Ohio. Complete hfe history through

22 instars.

Ephemen'dcB.

Morgan, A. H. 191 1. Maj^ies of Fall Creek. (Egg Laying

of Baetis.) Ann. Ent. Soc. Amer., Vol. 4: 371-41 1.

19 1 3. Contribution to the Biology of Mayflies. Ann,

Ent. Soc. Amer., Vol. 6: 371-413.
Murphy, H. E. 1922. Notes on the Biology of Some of our

North American Species of May-flies. Lloyd Library,

Bull., Ent. Series, No. 2: 1-46, Cincinnati, Ohio.
Needham, J. G. 1901. Ephemeridae. N. Y. State Mus.,

Bull., Vol. 47: 418-429, Albany.

1905. Mayflies and Midges of New York. N. Y. State

Mus., Bull., Vol. 86: 17-62, Albany.

1908. Notes on the Aquatic Insects of Walnut Lake.

Rep. Geol. Survey of Mich, for 1907: 252-271.

1920. Burrowing Mayflies of our Larger Lakes and

Streams. Bull. Bur. Fish., Vol. 36: 265-292.

417

BIBLIOGRAPHY

Odo7iata.

Needham, J. G. 1900. The Fruiting of the Blue Flag (Iris
versicolor L.) (Lestes and blue flag). Amer. Nat., Vol.

34: 374-375-

1903. Life-histories of Odonata. Suborder Zygoptera,

Damselflies. N. Y. State Mus., Bull., Vol. 68: 218-263,

Albany.

Needham, J. G., and Hejrwood, H. B. 1929. A Handbook
of the Dragonflies of North America. Charles C.
Thomas, Springfield, 111.

Wilson, C. B. 1920. Dragonflies and Damselflies in Rela-
tion to Pond-fish Culture, with a List of those found near
Fairport, Iowa. Bull. Bur. Fish., Vol. 36: 185-264.

Hemiptera.

Hungerford, H. B. 1919. The Biology and Ecology of

Aquatic and Semiaquatic Hemiptera. Kans. Univ. Sci.

Bull., Vol. II, No. 17. Excellent account of their biology.

Extensive bibliography.
Torre-Bueno, J. R. de la. 1905. Notes on Collecting,

Preserving and Rearing Aquatic Hemiptera. Can. Ent.,

Vol. 37: 12-24.

Neuroptem.

Anthony, M. H. 1902. The Metamorphosis of Sisyra.

Amer. Nat., Vol. 36: 615-631.
Davis, K. C. 1903. Sialidse of North America. N. Y. State

Mus., Bull., Vol. 68: 442-486, Albany. Life histories and

biology of this family.
Needham, J. G. 1901. Neuroptera; in Aquatic Insects in

the Adirondacks. N. Y. State Mus., Bull, Vol. 47: 555-

557, Albany.

Trichoptera.

Betten, C. 1901. Trichoptera; in Aquatic Insects in the

Adirondacks. N. Y. State Mus., Bull., Vol. 47: 501-572,

Albany.

418

BIBLIOGRAPHY

Krafka, J., Jr. 191 5. A Key to the Families of Trichopter-
ous Larvae. Can. Ent., Vol. 47: 217-225.

Lloyd, J. T. 1 92 1. The Biology of the North American
Caddice Fly Larvae. Lloyd Library, Bull., Vol. 21, Ent.
Series No. i, Cincinnati, Ohio.

Marshall, W. S., and Vorhies, C. T. 1905. The Repair
and Rebuilding of the Larval Case of Platyphylax desig-
natus Walk. Biol. Bull., Vol. 9: 232-244.

Murphy, H. E. 191 9. Observations on the Egg-Laying of
the Caddice Fly Brachycentrus nigrisoma Banks, and
on the Habits of the Young Larvae. Jour. N. Y. Ent.
Soc, Vol. 27: 154-159.

Noyes, A. A. 19 14. The Biology of the Net-Spinning
Trichoptera of Cascadilla Creek. Ann. Ent. Soc. Amer.,
Vol. 7: 251-271.

Vorhies, C. T. 1909. Studies on the Trichoptera of Wis-
consin. Trans. Wise. Acad. Sci., Vol. 16: 647-738,
Madison, Wise.

Lepidoptera.

Forbes, W. T. M. 1910. The Aquatic Caterpillars of Lake
Quinsigamond. Psyche, Vol. 17: 219-227. Photographs
of Nymphula maculalis, larva, gills, pupal case.
1 9 1 1 . Another A quatic Caterpillar (Elophila) . Psyche,
Vol. 18: 120-121. Cases on Lemna leaves.

Lloyd, J. T. 1914. Lepidopterous Larvae from Rapid
Streams. Jour. N. Y. Ent. Soc, Vol. 22: 145-152.

Welch, P. S. 19 16. Contributions to the Biology of Certain
Aquatic Lepidoptera. Ann. Ent. Soc. Amer., Vol. 9:
159-190. Excellent account of life history of Nymphula
maculalis.

Welch, P. S., and Sehon, G. L. 1928. The Periodic Vibra-
tory Movements of the Larva of Nymphula maculalis
Clemens (Lepidoptera) and their Respiratory Significance.
Ann. Ent. Soc. Amer., Vol. 21: 243-258.

419

BIBLIOGRAPHY

Coleoptera.

Blatchley, W. S. 19 lo. An Illustrated Catalogue of the
Coleoptera or Beetles (exclusive of the Rhyncophora)
Known to Occur in Indiana. Nature Pub. Co., Indiana-
polis, Ind.

MacGillivray, A. D. 1903. Aquatic Chrysomellidae and a
Table of the Families of Coleopterous Larvae. N. Y.
State Mus., Bull., Vol. 68: 288-327, Albany.

Matheson, R. 19 12. Haliplidse of North America, North
of Mexico. Jour. N. Y. Ent. Soc, Vol. 20: 156-193.

Needham, J. G., and Williainson, H. V. 1907, Observations
on the Natural History of Diving Beetles. Amer. Nat.,

Vol. 41 : 477-494.
Richmond, E. A. 1920. Studies on the Biology of the
Aquatic Hydrophilidae. Bull. Amer. Mus. Nat. Hist.,
Vol. 42, No. I, New York.

Diptera.

Alexander, C. P. 1919. The Crane-Flies of New York,
Part I, Distribution and Taxonomy of Adult Flies. Cor-
nell Univ. Agri. Exp. Sta., Mem. 25, Ithaca, N. Y.
1920. Idem, Part II, Biology and Phylogeny. Cornell
Univ. Agri. Exp. Sta., Mem. 25, Ithaca, N. Y.

Claassen, P. W. 1922. The Larva of a Chironomid which
is Parasitic upon a Mayfly Nymph. Kans. Univ. Sci.
Bull., Vol. 15, No. 16.

Johannsen, O. A. 1903. Aquatic Nematocerous Diptera.
N.Y. State Mus., Bull., Vol. 68, Ent. 18: 328-441, Albany.

Kellogg, V. L. 1 90 1, Food of Larvas of Simulium and
Blepherocera. Psyche, Vol. 9: 166-167.

Malloch, J. R. 19 1 4. American Blackflies or Buffalo
Gnats, U. S. Dept. Agri., Bur. Ent., Bull. No. 26, Tech.
Series.

Matheson, R. 1930. Biology of Mosquitoes. Charles
Thomas, Springfield, 111.

420

BIBLIOGRAPHY

Hymenoptera. (Minute wasp-like insects, not included in
this book.)

Matheson, R., and Crosby, C. R. 1912. Aquatic Hymen-
optera in America. Ann. Ent. Soc. Amer., Vol. 5: 65-71.
Excellent figure of the adult swimming.

CHAPTER XVI

SNAILS AND MUSSELS

Baker, F. C. 1918. The Productivity of Invertebrate Fish
Food on the Bottom of Oneida Lake, with Special Refer-
ence to Mollusks. Tech. Pub. No. 9, N. Y. State Col-
lege of Forestry, Syracuse Univ.

1928. The Fresh Water Mollusca of Wisconsin. Part I
Gastropoda, Part II Pelecypoda. Wise. Geol. and Nat.
Hist. Survey, Bull. No. 70, pt. i, Madison, Wise.

Lefevre, G., and Curtis, W. C. 1912. Studies of the Repro-
duction and Artificial Propagation of Fresh-Water
Mussels. Bull. Bur. Fish., Vol. 30, for 1910: 107-201.

CHAPTER XVII

FISHES

General References: Jordan, 1929; Ward and Whipple,
1918, Chap. 30, Eigenmann, C. H., The Aquatic Verte-
brates; Copeia; Aquatic Life.

A Biological Survey of the Erie-Niagara System, Sect. VI,
Fishes of the Erie-Niagara Watershed. Supp. to the
Eighteenth Ann. Rep., 1928, State of N. Y. Conserva- ,
tion Dept., Albany.

Adams, C. C, and Hankinson, T. L. 1928. The Ecology
and Economics of Oneida Lake Fish. Roosevelt Wild
Life Bull., Vol. i, Nos. 3, 4, Syracuse Univ. Bibliography.

Embody, G. C. 19 15. The Farm Fishpond. Cornell
Reading Courses. Country Life Series, No. 3, Ithaca,
N. Y.

421

BIBLIOGRAPHY

Foibes, S. A., and Richardson, R. E. 1909. The Fishes of
IlUnois. Bull. Illinois Nat. Hist. Survey, Vol. 3, Urbana.
Bibliography.

Gage, S. H. 1929. Lampreys and their Ways. Sci. Mo.,
Vol. 28: 401-416.

Greely, J. R. 1927. Some Common Non-Game Fishes of
New York. Cornell Rural School Leaflet, Vol. 2 1 :
57-74, Ithaca, N. Y.

Hankinson, T. L. 1909. Field Problems on Stream Fishes
for Secondary Classes. School Sci. and Alath., Vol. 9:
234-240. Suggestions for field work upon fishes of
ponds and small streams, — study of eggs and nests, blunt-
nosed minnow, nesting sunfish.

Jordan, D. S., and Evennann, B. W. 1903. American Food
and Game Fishes. Doubleday, Doran & Co.

Reighard, J. E. 1920. The Breeding Behavior of the
Suckers and Minnows. Biol. Bull., Vol. 38: 1-32.

Schmidt, J. 19 12. The Reproduction and Spawning Places
of the Freshwater Eel (Anguilla vulgaris). Nature, Vol.
89: 633-636.

1925. The Breeding Place of the Eel. Smithsonian Ann.
Rep. for 1924 : 279-316.

CHAPTER XVIII

SALAMANDERS, FROGS, AND TOADS, FOUND IN OR NEAR WATER

General References: Jordan, 1929; Copeia; Aquatic Life.
Babcock, H. L. 1926. Time Table of New England Frogs

and Toads. Bull. Boston Soc. Nat. Hist., No. 38: 11-14.
Bishop, S. C. 1925. The Life of the Red Salamander. Nat.

Hist., Vol. 25: 385-389 (eggs).

1926. Notes on the Habits and Development of the
Mud-puppy, Necturus. N. Y. State Mus., Bull., No. 268,
Albany.

422

BIBLIOGRAPHY

1927. The Amphibians and Reptiles of Allegheny State
Park. N. Y. State Mus. , Handbook, No. 3, Albany.

Boulenger, E. G. 1914. Reptiles and Batrachians. E. P.
Button & Co.

Dickerson, M. C. 1906. The Frog Book. Doubleday,
Doran & Co. Well written accounts of North American
frogs and toads, with a study of the habits and life-
histories of those of the northeastern states.

Dunn, E. R. 1926. The Salamanders of the Family Pletho-
dontidae. Smith College, Northampton, Mass.

Gage, S. H. 1891. Life History of the Vermilion-Spotted
Newt (Diemyctylus viridescens Raf.). Amer. Nat., Vol.
25: 1084-1110.

Noble, G. K. 1929. Further Observations on the Life-
history of the Newt Triturus viridescens. Amer. Mus.
Novitates, No. 348, Amer. Mus. Nat. Hist., New York.

Smith, B. G. 1907. The Life History and Habits of Crypto-
branchus allegheniensis. Biol. Bull., Vol. 13: 5-39.
1907a. The Breeding Habits of Amblystoma punc-
tatum Linn. Amer. Nat., Vol. 41: 381-390.

Wright, A. H. 1920. Frogs: Their Natural History and
UtiHzation. Bull. Bur. Fish., Doc. 888: 5-44.
1924. A Key to the Eggs of the Salientia East of the
Mississippi River. Amer. Nat., Vol. 58: 375-381.
1929. Synopsis and Description of North American
Tadpoles. Proc. U. S. Nat. Mus., Vol. 74: 1-70.

Wright, A. H., and Allen, A. A. 1908. Notes on the Breed-
ing Habits of the Swamp Cricket Frog, Chorophilus tri-
seriatus Wied. Amer. Nat., Vol. 42: 39-42.

CHAPTER XIX

TURTLES AND SNAKES, FOUND IN OR NEAR WATER

General References: Jordan, 1929.

Babcock, H. L. 19 19. The Turtles of New England. Mem-
oir Boston Soc. Nat, Hist., Vol. 8.

423

BIBLIOGRAPHY

Bishop, S. C. 1927. The Amphibians and Reptiles of
Allegheny State Park. N. Y. State Mus., Handbook,
No. 3, Albany.

Blanchard, F. N. 1925. A Key to the Snakes of the United
States, Canada, and Lower California. Mich. Acad.
Sci., Arts and Letters, Vol. 4, pt. 2.

Boulenger, E. G. 1914. Reptiles and Batrachians. E. P.
Button & Co.

Ditmars, R. L. 1908. The Reptile Book. Doubleday, Doran
& Co. Well illustrated and interesting accounts of the
turtles, tortoises, crocodilians, lizards, and snakes which
inhabit the United States and northern Mexico.

Sharp, D. L. 191 1. The Face of the Fields. (Chapter on
" Turtle Eggs for Agassiz.") Houghton, Mifflin & Co.
Also 1910. Atlantic Monthly. Vol. 105: 156-164.

Wright, A. H., and Funkhouser, W. D. 19 15. A Biological
Reconnaissance of the Okefinokee Swamp in Georgia —
The Reptiles. Proc. Acad. Nat. Sci., Phila. Vol.67:
io7~i39- (Eggs and nest of mud turtle).

424

GLOSSARY

Algae, simple chlorophyll-bearing plants most of which live

entirely submerged in water.
Anterior, front or head end.
Asexual, reproduction by other means than eggs and sperm

cells, e. g., budding as in hydra.
Auricle, a chamber of the heart which receives blood from

the veins; an ear-like lobe on a planarian.
Axolotl, a larva of A mby stoma tigrinum which matures sexually

without changing its larval form. Found only in the

southwestern United States.

Balancers, processes in front of the gills of certain tailed am-
phibians, as in salamander larvae.

Barbel, whisker-like feelers about the heads of some fishes,
e. g., the common bullhead.

Brackish, water which is partly salt and partly fresh.

Bryozoans, plant-like animals living in colonies, e. g., Crista-
tella.

Calcareous, limy or containing calcium carbonate.
Carapace, hard upper shell of turtles or of cr^ustaceans such as

crayfishes and lobsters.
Carnivorous, eating animal food.
Chitin, horny substance of the skeletons of insects and some

other arthropods.
Chlorophyll, green coloring matter of plants.
Cloaca, a cavity in the body of vertebrates into which the

intestine, urinary, and reproductive tubes open; not

found in most mammals.

425

GLOSSARY

Clypeus, the skeletal plate above the upper lip or labrum, in

insects.
Coelenteron, food cavity in hydra and related animals.
Crustaceans, animals with jointed bodies and appendages

and a limy skeleton.
Ctenoid, rough edged, said of the scales of fishes.

Dermis, an inner layer of cells in the skin of vertebrates.

Desmid, single-celled green plants apparently divided into
two parts by a light band.

Diatom, minute single-celled plants which are characteristical-
ly golden brown.

Dorsal, on or toward the back.

Elytra, homy front or outer wings of beetles.
Entomostracan, a minute crustacean, e. g., Cyclops.

Fertilization, the union of an egg cell and a sperm cell, fonning

a new individual.
Formalin, a solution of formaldehyde used as a preservative.

Gemmule, a capsule of sponge cells which live over the winter
and from which a new colony grows in the spring.

Gills, organs by which animals can breathe in water.

Glochiditmi, a larval mussel which lives as a parasite on the
skin of fishes.

Haemophilia, an hereditary disease, in which the blood does

not clot properly on exposure to air.
Hermaphrodite, having both male and female reproductive

organs in one individual; true of hydra, earthworms, and

many other animals.
Hibernate, to pass the r.'inter in an inactive dormant state.
Hydranth, one of the individuals which takes food in a

colony of hydra-like animals.

Imago, an adult, sexually mature insect.
Intemode, the part of a plant stem between the points from
which leaves spring forth.

426

GLOSSARY

Labrum, the upper lip of insects and of some other arthro-
pods.

Larva, an immature stage in the Hfe of certain animals; in
insects, the stage between the egg and the pupa.

Mandible, the bone of the lower jaw; in crustaceans, the

third pair of head appendages; in insects, the first or

upper pair of jaws.
Mantle, an outer fold of flesh in many animals; in clams and

other mollusks it secretes the shell.
Maxilla, one of the pair of lower jaws in insects, also present

in other arthropods.
Micropyle, a small opening in the outer covering of an egg

cell through which a sperm cell may enter.
Myriapod, a small arthropod with many pairs of legs, as

centipedes.

Node, the point on the stem of a plant from which the leaf

springs.
Nymph, an immature insect which undergoes only partial

change of form as it matures, e. g., mayflies, grasshoppers.

Operculum, a homy cover over the opening of the shell of

some snails; the gill cover of fishes.
Ovary, the organ in which egg cells develop.

Pallia 1 line, scar on the inner surface of clam and mussel shells
caused by attachment of muscles of the mantle.

Palp, a sensory organ near the mouth, often jointed as in
insects.

Parthenogenesis, the development of an egg without fertiliza-
tion by a sperm cell.

Peduncle, a short stalk, as the stem of a flower, or the stalk
of a crayfish eye.

Periostracum, the outer layer of a molluscan shell.

Petiole, the stem of a leaf.

427

GLOSSARY

Plankton, the population of minute plants and animals which
live in the surface layers of salt or fresh water.

Plastron, the under shell of a turtle.

Pollination, the transference of pollen or male cells to the
surface of the pistil in higher flowering plants.

Posterior, opposite from head end ; hind or tail end.

Prawn, a large shrimp-like crustacean.

Predacious, killing other animals for food.

Pronotum, dorsal region of the prothorax of an insect.

Pupate, in insects, to undergo a change from larval to adult
form.

Rhizoid, a root-like filament in lower plants.

Scud, a crustacean of the Order Amphipoda, e. g., Gammarus,
Hyalella.

Sessile, fixed to one place; not on a stalk or stem.

Setae, bristle-like appendages, in some insects extending back
as tails.

Silt, a fine earthy sediment carried and deposited by water.

Somite, a segment of the body, especially of worms, crusta-
ceans, and insects.

Spawn, to lay or produce eggs, especially of fishes.

Spermary, sex organ in which the male or sperm cells develop,
as in hydra.

Spicules, minute calcareous or siHcious bodies forming the
skeleton of sponges.

Spiracles, external openings in the respiratory or tracheal
systems of insects and some other arthropods.

Spore, an asexual reproductive cell capable of producing a
new individual without fertilization; a resistant stage
enabling small organisms to survive cold or drought.

Subimago, the nearly mature winged stage of mayflies.

Swimmeret, abdominal appendage of a crustacean.

Symbiosis, the association of two species of organisms, in an
advantageous partnership.

428

GLOSSARY

Tarsi, the segmented feet of insects and other arthropods.
Tentacle, a slender, unsegmented, feeler-Hke process.
Testis, the organ in which the male or sperm cells develop,

especially in higher animals.
Thorax, the division of the body posterior to the head; in

mammals, the division of the body containing the heart

and lungs.

Umbo, the thickening above the hinge on the shell of a clam.
Utricles, the little sacks or bladders, as in the bladderwort,
Utricidaria.

Ventral, the under side or front; opposite to the back.

Vivarium, a place for keeping live animals, as aquarium or
terrarium.

Whorl, a circular arrangement of leaves around a stem.

Zooecium, the outer shell-like tube of some bryozoans.

429

INDEX

Abbot, J. F., 226

Acarina (mites), 175

Achorutes socialis, 190

Acilius, 268

Acris gryllus, 376-378

Acroneuria pacifica, 195

Adam's pitcher, 97

Mdes, 98

/EschinincE, 218-220

Agrion, 220-221, 222; {Calop-
teryx) maculatum, 220-
221

Air-net, for collecting, 28

Alcohol, as preserving agent,
28, 36, 40, 41

Alderflies, 240, 241-243; eggs,
242; larvae, 242; smoky,
241-243

Alexander, C. P., 286, 287

Algae, Frontispiece, 46-51,
192; "blanket", 31, 34, 50;
Blue-green, 47-48; Brown,
47 ; classes of, 47 ; collection
of, 31 ; Diatoms, 47, 51 ; fila-
mentous, 239, 286; Green,
34, 36, 47, 48-51, 52, 121;
in aquaria, 40; in riffies and
rapids, 33-34; in springs,
34; in waterfalls, 25; light
needed by, 10, 11; marine,
47; mats of, 144, 303; ooze
of, 260; Red, 47; Yellow-
green, 47

Alisma, 237; Plantago-aqua-
tica, 78-79

AlismacecB, (Water plantains
and arrowheads), 76-79

Allocapnia, 193, 194; vernalis,
198

Alloperla, 196

Ambystoma, 35, 351; je-0er-
sonianum, 361-362; macu-
latum, 348, 351, 354, 357-
358, 384; opacum, 360, 361 ;
tlgrinum, 358-360

AnihystomidcB {mole salaman-
ders), 357-358

Ameirus melos, 338; nebulosus,

337-338

Ameietus, 210

Amnicola, 314; limosa, 313;
limosa porata, 313

Amnicolidce, 313, 314

Amphibians, 347-388; aquar-
ium and vivarium study,
351-352; breeding habits,
349-350; food, 348; frogs,
12, 17, 28, 30, 31, 34, 35,
36,40,41,50, 156,373-380;
giant salamanders, 352-
353; habitat, 348; habits,
347-348; life history, 350-
351; lungless salamander,
362-366 ; mole salamanders,
357-363 ; mud-puppies, 1 19,
347, 366-368; newts, 207,
347, 352, 353-357; toads,
35, 347-352, 368-373

Amphipoda (scuds), 161, 169

Amy da spinifera, 402-404

Anahcena, 48

Anax, 219-220, 264; Junius,
219

Ancylidce, 312-314

Ancylus, 34, 312-314; paralle-
lus, 313, 314; rivularis, 313,

314
Andrews, E. A,, 172

431

INDEX

Angiosperms, 66-103; arrow-
heads, 1^11 \ iDladder-
worts, 100-103; bur-reeds,
70-73; cat-tails, 68-70;
duckweeds, 82-85; e^^-
grass, 82-85; mustards and
cresses, 95-96; parts of
flower, 66-68 ; pickerel-
weeds, 85-89; pitcher-
plants, 96-98; pondweeds,
73~'75; smartweeds, 89-90;
sundews, 98-99; water-lil-
ies, 91-95; water milfoils,
99-100; water-plantains,
78-79; water- weeds, 79-
80

Anguilla bostoniensis, 331-332

Angiiillida (eels), 331-332

Animals, care of young, 36-
37; collecting, 31, 32; dis-
tribution in ponds and
streams, 15-17; in aquaria,
38-39; in blanket algae, 50;
killing, 40-41; larger, in
ponds, 17; in rapids, 25;
life in streams and marshes,
20-21; life history cages,
36-37; preserving, 40-45;
relaxing, 41 ; similarity be-
tween algae and, 50

Anisoptera, 216-218

Annelida, 143, 148

Anodonta, 119, 321; cataracta,
321

Anopheles, 295-296

Aquaria, 37-40

Aquarium net, 30; supplies,
408-409

Antocha, 284, 285, 288

A nura (toads and frogs) , 368-
388; BufonidcE, 368-371;
HylidcB, 373-378; Pe-
lohatidcc, 371-373; Ranidce,
379-388

A rctocorixa (Corixa) alter-
nata, 239-240

Argia violacea, 222, 224

Arrowheads, 13, 58, 73, 76-
77; broad-leaved, T(i-77,
192

Arthropoda, 158

Arzama obligua, 70

Asellus, 22, 34, 169, 171, 172
Axolotls, 359, 360

Bacillariacece (yellow-green
algcE), 47

Backswimmers, 36, 227, 237-
238, 192; as food, 244; re-
productive capacity, 237

Bacteria, sulphur, 48

BcBtincB, 208-211

BcBtis, 201, 213

Bag, bobbinet, for collecting,
26

Baker, F. C, 264, 302, 303

Balance of life, maintenance
of, 17-18

Bass, 341, 342-343; bait for,
243; black, 152, 335, 341,
342-343 ; large-mouthed
black, 342, rock, 341 ; small-
mouthed, 342-343

Bedstraw, 78

Beetles, 13, 15, 25, 59, 95, 98,
179, 188, 190, 215, 261-
281; aquarium study, 264,
as food, 264; associates,
263-264; crawling water,
264, 265-266; diving, 192.
262, 265, 265-271 ; enemies,
263; food, 50, 263,264; hab-
its, 262-263; identification,
264-281; larvae, key to,
265; leaf, 73, 93, 278-281;
riffle, 265, 277-278; season,
262; snout, 70; tiger-, 15,
17; water scavengers, 264,
273-277; whirligig, 11, 36,
91, 226, 262, 263, 264, 271-

273
Bell-animals, 56
Belostoma, 226; fiumineum,

232-234
BelostomatidcB, 227, 232-235
Benacus griseus, 236; 234-235
Berosus, 275-277
Birds, 286, 287; wading, 152,

287; water, 264, 324
Bittacomorpha, 287; clavipes,

287
Black-flies, 23, 34, 248, 283,

296-297
Blackwings, 220-221

432

INDEX

Bladder worts, 59, 100-103,

164, 167, 258
Blasturus, 39, 200, 208
Blepharocera, 297
BlepharoceridcB (net-veined

midges), 283, 297-298
Blood-sucker, 150, 151, 152,

155-156

"Bloodworms," 144, 286, 292

Bog mosses, see Sphagnums

Boleosoma nignim, 344-345

Bottles, collecting, 26; cya-
nide, 29; killing, 28, 29;
specimen storage, 41-42

Bottom, collecting on, 33

Brachycentrus, 257

Branchiopoda (fairy shrimps) ,
160, 161-163

Bristleworms, 139-140, 143-
147; aquarium study, 144;
collecting, 144; food, 144-
145; habitat, 144; identifi-
cation, 145

Britton, 234

Brooks, collecting season, 35;
population of, 36

Bryophyta (liverworts and
mosses), 59-66; Fontinala-
cecB, 62-64; HepaticcB, 59-
60 ; HypnacecB, 64-66 ;
Musci, 60-66

Bryozoa (Polyzoa), 1 31-138

Bryozoans, 31, 32, 36, 95, 107,
1 31-138; aquarium study,
133-134; collecting, 133-
134; food, 133; food tube,
132; form and habits, 131-
133; identification, 134; in
reservoirs, 133, 135, 138; on
lily pads, 15

Buckwheats, 89

Buemoa margaritacea, 238

Bufo americaniis, 368-370,
2,S4; fowleri, 370-371

BufonidcB (toads), 368-371

Bulimus, 314

Bullfrogs, 30, 31, 36, 347, 348,
352, 387-388

Bullheads, 74, 337-338; black,
338; common, 337-338;
deepwater, 338; mongrel,
338

Bulrushes, 13, 30, 76
Bur-reeds, 70-73, 76; branch-
ing, 73; giant, 73

Caddis flies. Frontispiece, 22,

34. 35. 95. 179. 188, 190,
247-257, 276, 282; habitat
and season, 249; larvae, 247,
253, see also caddis worms;
microcaddis flies, 249;
nymphs, 34; pupae, 248

Caddis worms. Frontispiece,
3,25,36, 144, 192, 195,211,
243, 247, 248, 252; larvae,
transient ponds, and, 1 1 ;
net building, 8, 19, 22, 34,
249, 251

Ccenis, 33, 201, 210

Cages, life-history, 36-37

"Caledonia shrimp", 169

CallibcBtis, 16, 18, 19, 39, 192,
199, 200, 208-209, 272

Calopteryx, see Agrion

Calvert, Philip, 218

Cambarus affinis, see C. limo-
sus; bartoni, 172, 174;
diogenes, 172, 174; immu-
nis, 226; limosus, i'j2j 174

Campeloma, 308

Candlewicks, 70

Capnella, 194, 198

Capnia, 193, 194; vernalis, see
AUocapnia vernalis

Carbon dioxide, relation of,
to food content of water,
9-10; to balanced aquarium

38
Carbon tetrachloride, 29

Carbona, for collecting and

killing, 28, 29, 40
Carchesium, 56, 57
Carpenter, Dr. Kathleen, 122
Carps, 334

Castalia odorata, 93-95
Caterpillars, 93, 139, 257-

261; canopy, 260, 261;

food of, 260; lily-leaf, 258-

261; water, 257-261
Catfish, 31, 216, 326, 337-

338; yellow, 326
CatostomidcB, (suckers) 332-

333

433

INDEX

Catostomus commersonii, 332-

333
Cat tails, 13, 20, 48, 68-70,

83, 229, 237, 289; broad-
leaved, 68-70; narrow-
leaved, 70

Cat-o'-nine-tails, 70

Cat-tail flags, 70

Cattle, 156

Celery, wild, 39

CentrachidcB (sunfishes and
bass), 3417343

Ceratodaphnia, 165

CeratophyllacecB (horn worts),
90-91

Ceratophyllum, 90-91; demer-
sum, 90-91

Ceratopogon, 292

Chcetogaster, 146; diaphanus,
146

ChcctopJiora, 52

Chaoborus, 294

Chara, 31, 226, 230, 239, 265,
266, 275, 356, T,85;fmgilis,

53> 54, 55
CharacecB (stoneworts) , 53-54
Charr, 330
Chauliodes, 241 ; pectinicornis ,

244-245
Chelydra serpentina, 391-393
Chelydridce (snapping tur-
tles), 391-393
ChironomidcB, 283, 289-293
Chironomids, 75, 290-292
Chironomus, 248, 292, 293
Chirotenetes, 22, 207, 209-

211, 257
Chloretone, as killing agent.

Chloroform, as killing agent,

40-41
Chloroperla, 196
Chlorophycece (green algae) , 47
Chlorophyll, 47
Chrysemys marginata, 399;

picta, 397-399, 400
Ckrysomelidce, 278-281
Chrysops, 276, 299
Chub, 336
Chydoris, 146
Cladocera (water-fleas), 146,

160, 161, 164-165

Cladophora, 22

Clam worms, 144

Clams, 21, 158, 301; "finger-
nail", 301, 315, 321-323;
food for hydras, 116; pill-,

323
Clemens, W. A., 211

Clemmys guttata, 399, 400;
insculpta, 399-402

Climacia, 241, 246

Closterium, 49, 52

Coelenterata , 11 2-1 18

Colandra pertinax, 70

Coleoptera (beetles), 179, 190,
261-281; key to families,
264-265 ; ChrysomelidcB,
278-281; Dytiscidce, 266-
271; GyrinidcB, 271-273;
Haliplidce, 265-266; Hy-
drophilidcE, 273-277; Pse-
phenidcE, 277-278

Collecting, equipment, 26-
30; where and how, 30-36

Collembola (springtails), 179,
190-192

ColubridcB (water snakes),
405-406

Comstock, J. H., 278

Copepoda (copepods), 160-
161, 166-167

Coptotomus, 268-269

Cordulegaster, 21, 34

Corethra, 294

Corixa alternata, 239

CorixidcB (water boatmen),
227, 239-240

Corydalis, Frontispiece, 241,
242, 244; cornuta, 243-245

Cottidce (sculpins), 345-346

Cottus, 345-346; bairdii, 345-
346; cognatus, 346

Coves, collecting in, 33

Cows, and horseflies, 299

Craneflies, Frontispiece, 282,
283-289; adults, 284; asso-
ciates, 286-287 ; bobbing by,
284; collecting, 34, 35;
food, 286; giant, 289; hi-
bernation, 286; identifica-
tion, 287; larvae, 284-285;
phantom, 282, 287-288;
pupae, 286, typical, 288-289

434

INDEX

Craspedacusta, 115

Crawlers, 243

Crayfish, 8, 33, 36, 159, 160,
172-174, 226, 342; aquar-
ium study, 173-174; pre-
serving, 41

Cresses, 95-96

Crickets, 142

Cristatella, 133, 134; mucedo,

CristatellidcB, 137-138

CrucifercB (mustards and
cresses), 95-96

Crustacea (crustaceans), 158-
174; key to orders, 1 60-1 61 ;
Amphipoda, 161, 169-171;
Branchiopoda, 160, 161-
163; Cladocera, 160, 164-
165; Copepoda, 160, 166-
167, Decapoda, 161, 172-
174; Entomostraca, 160,
161-168; Isopoda, 161, 171-
172; Malacostraca, 160,
168-174; Ostracoda, 161,
168; Phyllopoda, 160, 161-

165
Crustaceans, 22, 31, 34, 48,

50, 57, 100, 103, 117, 146,
158-174, 215, 226, 257; as
food, 17, 238; associates,
162; copepods, 166-167;
crayfish, 172-174; fairy
shrimps, 1 61-163; food,
162; form and habits, 158-
159, 162; identification,
1 59-1 61; in plankton, 17;
in transient ponds, 1 1 ; os-
tracods, 168; preserving,
41 ; relation to food content
of water, 9, 13, 17; repro-
ductive capacity, 19; scuds,
169-171; sow-bugs, 171-
172; water-fleas, 164-165

CryptohranchidcB (giant sala-
manders), 352-353

Cryptobranchus alleganiensis ,

352-353
Crystal worts, 60
Culex, 295
CulicidcB (mosquitoes), 283,

290, 293-295
Culicoides, 292-293

Cyanide, potassium, killing

bottles, 28, 29, 40
CyanophycecB (blue green

algae), 47
Cy bister, 270-271
Cyclops, 17, 116, 159, i6(>-

161, 326
Cyprinidce (minnows and

carps) 334-337
Cypris, 116

Dace, black-nosed, 334-335;
horned, 336

Damselflies, 76, 88, 179, 188,
189, 213-216,220-225,326;
adults, 213-214; associates,
216; food, 215; nymphs, 15,
36, 214-215; occurrence,
215; preservation, 43

Daphnia, 113, 115, 116, 158,
160; pulex, 19, 165

Darters, 325, 343, 344-345;
in rapids, 22, 34; Johnny,
344-345; rain bow, 326;
tesselated, 345

Darwin, Charles, 144

Davis, 244

Decapoda (crayfish), i6j, 172-

174
De Geer, 191

Dendroccelum, Frontispiece,
125; lacteum, 122, 126

Dero, 144, 146-147

Desmids, 47, 48-49, 50, 52,
203, 348; distribution in
pond life, 13; in plankton,
16; in rapids, 22; in springs,
34; light needed b}^ 10,
II

Desmognaihus fuscus, 354,
362-363 .

Devil's darning needles, 213

Diaptomus, 167

DiatomacecE, (diatoms) 47

Diatoms, 46, 47, 50, 51, 52,
55, 162, 165, 203, 205, 257,
263, 286, 296; distribution
in pond life, 1 3 ; in plankton,
16, 17; in rapids, 22, in
springs, 34 ; light needed for,
10, II; reproductive capac-
ity, 17; silica shell, 51

435

INDEX

Diclielyma, 62; capillaceum,
62-63

Dickerson, 370

Dicranomyia, 34, 284

Dineiites, 272, 273

Diptera (flies), 179, 189,282-
300; key to larvae, 282-283;
BlepharoceridcB, 283. 297-
298 ; ChironofuidcB, 283, 289-
293; CuUcidcE, 283, 293-
296; PtychopteridcB, 282,
287-289; Simuliid(B, 283,
296-297 ; Strati omyiidcB, 2 83 ,
299-300; Syrphidcc, 282;
Tahanidcc, 283, 298-299;
Tipulidcc, 283-287

Dishes, aquaria, 38

Ditch-moss, 80

Ditmars, R. L., 394, 406

Dobson-flies, 240, 241, 244-245

Donacia, 59, 73, 93, 192, 265,
278-281

DonaciincB, 278-281

Dragonflies, 76, 88, 179, 185,
186, 188, 189, 192, 213-219.
226, 263, 267, 272, 286,
303; adults, 213-214;
aquarium study , 216;
associates, 215-216; col-
lecting, 34, 35; food of, 17,
50, 215; in aquaria, 39;
killing of, 40; larvce, 15;
life history cages, 36, 37;
nymphs, 3, 18, 21, 26,
33. 34. 36, 214-215, 264,
300, 302; occurrence, 215;
preservation, 42

Drosera rotundifolia, 98-99

Droseracea (sundews), 98-99

"Dry flies", as bait, 199

Dryopidce, 262 .

Ducks, 74, 75, 82, 83, 264

Duckweeds, 11, 13, 14, 31,
59, 60, 82-85, 168, 228,
229; greater, 82-83; ivy-
leaved, 83-84; lesser, 84

"Duns", 199

DytiscidcB (diving beetles),
263, 265, 266-271

Dytiscids (diving beetles),
266-271, 274

Dytiscus, 192, 262, 268, 271

Earthworms, 139, 143, 145
Eelgrass, 15, 80-82
Eels, American, 331-332
Electric-light bug, 233-234
Electric lights, collecting

near, 35, 247
Elliptio complanatus, 320-

321
Elodea, 37, 38, 52, 58, 79-80,

116, 117, 170, 192, 230,

258, 304, 309, 323, 356;

canadensis, 79-80
Elophila fulicalis, 260
Embody, G. C, 170, 171,

335
Enallagma, 214, 216, 224;

aspersum, 214; exsula^is,

222,
EnchytrcBidcB, 216
Enock, 236
Entomostraca, 160, 161- 165;

Branchiopoda, 161-163;

Cladocera, 164-165; Cope-

poda, 1 66- 167; Ostracoda ,

168-169; Phyllopoda, 161-

165
Entomostracans, 52, 275, 294
Envelopes, storage, 42
Epeorus, 23, 199, 211-21^
Ephemera, 19, 33, 206, 207
Ephemerella, 210; rotunda,

185, 187
Ephemerida (mayflies), 179,
189, 198-213; Bcctince, 208-
211; EphemerincB, 204-207;
HeptagenincE, 2 1 1-2 1 3
Ephemerince (burrowing may-
flies), 204-207, 210
Ephippium, 165
Epicordidia, 302
Epiphragma, 284, 285
Epistylis, 46, 56-57
Equipment, collecting, 26-

EsocidcB (pickerel), 338-339
Esox niger, 338-339
Eiihranchipiis, 162; vernalis,

163
Eucalia inconstans, 339-341
Euglena, 49, 51
Eupomotis gihhosus, 340, 341-

342

436

INDEX

Eurycea hislmeata, 354, 365-

366
"Eyestones", 307
Eylaince, 177
Eylais extejidens, 177

Fairy shrimp, 8, 11, 159, 160,
1 61-163; food, 162; habi-
tat, 162; associates, 163;
identification, 163; season,
162

Fernworts, water, 31

Ferrissia, see Ancyliis

Fever-cup, 97

Fire "flies", 262

Fish-flies, 240, 244-245; eggs,
245; length of larval life,
244

Fishes, 156, 215, 226, 324-
346; aquarium study, 326-
327; breeding habits, 324-
325, 328, 332, 333, 334,

335, 336, 337- 338, 339,
340, 341, 342, 343, 344,
346; food, 17, 18, 75, 216,
302, 303, 326; in lakes, 19;
in rapids, 22; in shallows,
31 ; killing of, 40; structure,

324-32. S

Flatworms {Planaria), 119-
126

Fleas, water-, 3, 160, 161,
164-165

Flies, 98, 179, 188, 189, 282-
300; black-flies, 23, 34,
248, 283, 296-297; Crane-
flies, 283-289; horse-flies,

282, 283, 298-299; key to
larvae, 282-283; midges,
15, 16, 17, 20, 21, 22, 25,
34, 50, 215, 226, 257, 282;
mosquitoes, 215, 226, 282,

283, 290, 293-296; net-
veined midges, 283, 297-
298; soldier-flies, 283, 209;
syrphus-flies, 79, 282, 299-
300

Flower, parts of, 66-68
Flukes, 119

FontmalacecB (fountain-

mosses), 62-64
Fontinalis, 22, 25, 34; gigan-

iea, 63-64; NovcE-Anglice,
63-64
Forceps, for collecting, 26,

30

Fork-tails, 225

Formalin, preserving agent,

40,41
Fredericella sultana, 135
FredericelUdo', 135
Frogs, 3, 152, 156, 286, 324,

347-352, 368, 373-378, 379-
388 ; as food, 1 7 ; bull frogs,

30, 31, 36, 347, 348, 352,
387-388; cricket, 376-378;
collecting, 28, 30, 31, 34,
35; eastern wood, 382-
384; eggs, 12, 156; food of,
302; green, 30, 31, 36, 352,
.385-386; in vivaria, 40,
killing of, 40; legs, number
consumed, 381; leopard,
379-381; meadow, 379-
381 ; pickerel, 381-382; pre-
serving, 41 ; spring peeper,
352, 375-376, 386; swamp
cricket, 378; tree, 352, 373-
375, 386; wood, 382-384
"Frog-spittle", 50

Galerucella nymphcua, 281

GalenicincB, 278

Gammarus, 34, 170, 171;

fasciatus, 171; limncEiis,

169
Garman, 291
Gasterosteidcc (sticklebacks) ,

339-341

Gastropoda (snails), 301-315;
Amnicolidcp, 314; Ancylidce,
313-314; LymncEidcB, 308-
310; FliysidcE, 3 10-31 1,
Planorhida, 311-312; Pleu-
roceridce, 315; Valvatidcs,
315;. ViviparidcB, 315

Gemmules, sponge, Frontis-
piece, 106, 107, 108, 109,

Gerridce. (water striders), 228,

230-232
Gerris conformis, 231-232;

marginatus, 232; remigis,

231

437

INDEX

Glochidia, 319-320, 321
Glossiphonia complanata,

154-155,302
Glossiphonidce, 149, 152, 153,

154-155
Glossosoma, 250; americana,

250-251
GlossosomatincB, 250-251
Gnathobdella, 153
Gnats, 282
Goer a, 257
Gold fish, 334
Gomphincc, 218
Gomphus, 214, 218
Goniohasis, 34, 314. 315
Gordiacea (hairworms), 141-

142
Gordius aquaticus, 142; rohus-

tus, 142; villoti, 142, 143
Grasses, marsh, 13
Grasshoppers, 142
Graulus hirsutiis, see Plan-

orhis hirsutus; parous, see

Trivolvis parvus
Green darners, 219
GymnolcBmata, 134
GyrinidcB (whirligig beetles),

262, 263, 264, 265, 271-273
Gyrinids, 262, 263, 264, 271-

273
Gyrinophilus porphyriticus,

366

Gyrinus, 272

Hcemopsis, 156-157; mar-

moratis, 156-157
Hairsnakes, 141
Hairworms, 139-140, 141-

143; form and habits, 141-

142
Hale, 239
HaliplidcB (crawling water

beetles), 263, 264, 265-

266
Halipus, 265, 266; ruficollis,

266
HaloragidacecB (water mil-
foils), 99-100
Hand-bulbs, for collecting,

30

Hand-lens, for collecting, 26
Harris, J. A., 268

Hegner, R. W., 102

Helico psyche, 248, 256

Helisoma trivolvis, see Plan-
orhis trivolvis

Helius, 289

Hellbender, 347, 352-353

Hellgrammites, 243

HemerobiidcB, 189, 241

Hemiptera (water-bugs),

179, 189, 207, 225-240,
262; key to families, 227-
228; Belostomatid<T, 227,
232-235; Corixidcp, 227,
239-240; Gerridce, 228, 230-
232; HydrometridcE, 227,
228; MesoveliidcB, 228;
Naucoridce, 227, 238-239;
NepidcE, 227, 235-237; No-
tonectidce, 227, 237-238;
Veliidce, 228, 229-230

Hepaticce (liverworts) , 59-
60

Heptagenia, 23, 199, 212

HeptagenincB, 21 1-2 13

Hermaphroditism, 120, 148,
308, 318

Herpobdella punctata, 157

HerpobdellidcE, 153, 156-157

HetcBriyia americana, 221-
223

Heteranthera dubia, 88-89

Hexagenia, 19, 33, 204-207,
211; bilineata, 205

Hickson, S. J., 116

Hippuris vulgaris, 99-100

Hirudin, of leech, 151

Hirudinea (leeches), 148-157,

155
HirudinidcE, 153, 155-156
Hirudo medicinalis, 150
Homed pout, 337-338
Horn wort, 15, 59, 90-91,

130
Horse-flies, 276, 282, 283,

298-299, adults, 299; eggs,

299; larvae, 298
Horseradish. 96
Hot springs. Blue-green

algae, in, 48
House-flies, 244, 282
Hungerford, H. B., 226, 227,

229, 237, 238, 239

438

INDEX

Hyallela, 170, 171; knicker-

bockeri, 170
Hyborhynchus notatus, 336-

337
Hydra, 246; fusca, see H.

oligactis; grisea, see //.

vulgaris; oligactis, 118; vir-

idis, 118; viridissima, 114,

118; vulgaris, 118

Hydras, 52, 112-118; aquar-
ium study, 1 1 6-1 17; associ-
ates, 116; brown, 118;
brown and green, 167; col-
lecting, 1 1 6-1 17; food, 116;
form and habits, 11 2-1 15;
identification, 117

Hydracarina (water-mites) ,

175-178

Hydrachna, 175; geographica,
177-178

HydrocharitacecB (water- weeds
and eel-grass), 79-82

Hydrometra martini, 228-229

HydrometridcB (water-measur-
ers), 227, 228-229

Hydrophilidce (water scaveng-
ers), 262, 263, 264, 265,

273-277.
Hydrophilids, 262, 267, 273-

277

Hydrophilus, 274, 275

Hydroporus, 263
Hydropsyche, Frontispiece, 22,

195, 211, 251-253
HydropsychtdcB, 249, 251
HydroptilidcB (microcaddis

flies), 249
Hydrozoa (hydras), 117
HygrohatincE, 178
Hygrohypnuni, 25, 34, 64;

ochraceum, 64
Hyla crucifer, 352, 375-376,

386; pickeringi, see H.

crucifer; versicolor, 352,

373-375, 386
HylidcB (tree frogs), 373-

375
Hymenoptera, 179

HypnacecB (hypnums), 64-65

Hypnums, water, 64-65

Jcthyobdellidce, 153

Insecta, 179-300; key to
orders of nymphs and
larv£e, 189-190; Coleoptera,
190, 261-281; Collembola,
190-192; Diptera, 189,282-
300; Ephemerida, 189, 198-
213; Hemiptera, 189, 225-
240; Lepidoptera, 190, 257-
261; Neuroptera, 189, 190,
240-246; Odonata, 189,
2 1 3-2 2 5 ; Plecoptera, 1 89 ,
193-213; Trichoptera, 190,
247-257

Insects, 103, 152, 154, 179-
300; adults, 263; alder-
flies, 240, 241-243; aquatic,
31, 57, 178; as food, 116;
beetles, see beetles; caddis-
flies, see caddisflies; dob-
son-flies, 240, 241, 243-
244; dragonflies and damsel
flies, see dragonflies; Dytis-
cidce, 267; fish-flies, 240,
244-245; flies, see flies;
flying, collecting of, 28;
growth of, 185-188; key
to orders (nymphs and
larvae), 189-190; im-
mature, in rapids, 22; kill-
ing of, 29, 40; lily pads,
hatchery for, 15; mayflies,
see mayflies; moths, see
moths; parts of, 180-185;
preserving of, 40-45; re-
laxing of, 41, 42, 43; spon-
gilla-flies, 109, 240, 245-
246; springtails, 31, 179,
190-192, 226; stoneflies see
stoneflies; water-bugs, see
water-biigs

Iron, 23, 21 1-2 13

Ischnura, 214, 224; verticalis,
224-225

Isopoda (sow-bugs), 161, 171-
172

Ithytrichia confusa, 249

Jellyfishes, fresh water, 112-

118
Joint weed, 99-100
June "bugs", 262

439

INDEX

Kerona pedicidus, ii6
Kinosternidcc (box turtles),

393-397
Kinosternum subrubrum, 394-

397

Knapsack, canvas, 28

Knotweeds, 89
Kofoid, 115
Krafka, 253
Krecker, F. H., 205

Labels, for specimens, 42

Lakes, temperature, 9; dis-
tribution of life in, 19-20;
light in, 10

Lamprey eels, see lake

, lamprey

Lampreys, 327-329; lake,

327-329

Land, collecting on, 34-35
Larva, definition, 187, 188
Lasmigona complanata, 301
Leaf -barriers, collecting in, 34
Leaf-beetles, 73, 93, 192, 278-

282
Leaf-miners, 93
Leeches, 21, 22, 26, 31, 34,
148-157, 302, 303; aquar-
ium study, 152-153; associ-
ates, 152; blood sucking,

150. 151. 152, 155-156;
food, 152; horse, 156-159;
identification, 153; medic-
inal, 150, 155-156; * col-
lecting, 152-153; hirudin,
151; habitat, 1 51-152; pre-
servation, 41; turtle, 154

Lemna, 168; minor, 84; tris-
cula, 83-84

LemnacecB (duckweeds), 82-

85

LentibtdariacecB (bladder-

worts), 100-103

Lepidoptera (moths), 179,
190, 257-261

LeptoceridcE, 254

Leptocerus, 254

Leptodora, 164

Leptophlebia, 35, 199

Lestes, 223; incBqualis, 222

Lethocerus americanus, 233- I
234 '

Libellula, 216-217; ptilchella,

192
LibelhdidcB, 2 1 6-2 1 8
"Lifters", wire, for collecting,

.30
Light, in water, 10, 11

Lily pads, 11, 13, 14, 15, 32,

95, 130, 138, 139, 254, 258,

.259,279
Lime, secreted by Char a, 53
Limn abates, 228
Limnochares aqiiatica, 176,

177
Lim?wcharincB, 176
Limnophila, 256
Limnophilidce, 256, 286, 289
Limnophiliis combinatus, 256
Limpets, 312-314
Liverworts, 15, 31, 59-60
Lloyd, J. T., 255
Lobsters, 158
Liimbricus terrestris, 144
Lymnaa, 74, 302; columnclla

{Pseudosiiccinea), 310; pal-

ustris, 308; stagnalis, 271,

309-310
LymnccidcB (pond snails),

308-310
Lymncecia phragmitella, 70

MacGillivray, A. D., 280
Macrobdella, 150; decora, 150,

152, 155-156
Macronema, 252, 253; see also

Hydropsyche
"Maggot, rat-tailed", 300
Malacostraca, 160, 161, 168-

174; Amphipoda, 161, 169-

171; Decapoda, 161, 172-

174; Isopoda, 161, 171-

172
Malacostracans, 168-174
Mare's tail, 99-100
Ma rga rita n idee, 320
Marshes, life in, 20
Mason fruit jars, for frogs'

eggs, 28
Matheson, R., 265
Mathews, Schuyler, 96
May beetles, see June ''bugs'*
Mayflies, 3, 16, 17, 19, 22, 23,

25. 33, 34, 35, 36, 39, 50,

440

INDEX

Mayflies — Continued

58, 179, 183, 184, 185, 186,
188, 189, 192, 195, 198-
213, 257, 263, 272, 276,
303; adults, 199-203;
aquarium study, 39, 204;
artificial, as bait, 199; as
food, 243; associates, 204;
burrowing, 19, 21, 33, 204-
207; clamberers and run-
ners, 204, 208-2 1 1 ; collect-
ing, 33- 34» 35; egg-laying,
201-203; food, 203; habi-
tat, 203; identification,
204; life-history cages, 36;
mating, 201; nymphs, 16,
17- 34. 39,199; reproductive
capacity, 18-19; sprawl ers,
204, 21 1-2 I 3

Medicine-droppers, for col-
lecting, 30

Melicerta, 15, 130

Metamorphosis, in insects,
185-188

MesoveliidcE, 228

Miall, L. C, 191

Micropterus dolomieu, 342-

343

Midges, 22, 25, 50, 52, 215,

226, 282; Chironomids,
283, 290, 291, 292; food for
larger insects, 17; larva?,
15, 16, 17, 20, 21, 25, 34,
139, 144, 257; net-vemed,
283, 297-299

Milfoils, feathery, 58; water,
99-100, 130

Milkweeds, swamp, 79

Miller's thumb, 345-346

Minnows, 319, 326, 334-337;
blunt-nosed, 326, 336-337;
in rapids, 22, 34

Mites, 175; see water-mites

"Moccasin", 405-406

Molanna, 254

MolannidcB, 254

Mollusca (mollusks), 301-
323; Gastropoda, 304-315;

Pelecypoda,2>i 5-323
Mollusks, 14, 256, 301-323;

associates and enemies,

302-303; habits and habi-

tat, 301-302 ; collecting and
aquarium study, 303-304;
mussels, 315-323; see also
mussels; snails, 304-315;
see also snails

Montgomery, 142

Mosquitoes, 98, 215, 226,
282, 283, 290, 293-296;
Anopheles, 295-296; Culex,
295; eggs, 294; habits, 293,
294; larvae, 8, 293; larvae,
as food, 239; life history,
study of, 37; malaria, 293,
295-296; phantom larvee,
294; pupai, 293; wrigglers,
3, 293; yellow fever, 293,

295

Moss animals, 131-138

Mosses, 22, 25, 33-34. 59.
60-66; fountain, 22, 25, 62-
64; life history, 61; peat,
65-66; "red-tipped", 61;
■ "reindeer", 61; sphagnum,
see sphagnum moss

Moths, 75, 98, 179, 188, 190,
257-261; cat-tail, 70; leaf-
mining, 70

Mud-puppies, 119, 347, 366-
368

Muddlers, 345-346

Mufflejaws, 345-346

Mullets, 332-333

Musci (mosses), 60-66

Musculium, 322-323

Muskrats, mussels as food of,
302-303

Mussels, 34, 36, 119, 178,
301-304, 315-323; as food,
302-303; aquarium study,
303-304; body, forms, 317-
318; clams, 21, 116, 158,

301, 315. 32 1-323; 'eggs and
young, 318-320; enemies,
302-303; habitat, 301-302;
in lakes, 20; in pools, 34;
in streams and marshes,
21; on bottom, 33; paper-
shells, 321; pearly, 320-
321; shell, form and move-
ments, 316-317; shell
growth, 317; sphere-shells,
34. 322

441

INDEX

Mustards, 95

Myriapods, 154

Myriophyllum, 39, 48, 55,
58, 90, 117, 122, 170, 192,
304, 309; spicatum, 99-
100

NaidcB, 144
Nats, 16, 145-146
NajadacecB (pond weeds), 73-

75
Natrix sipedon, subspecies

sipedon, 404-406

NaucoridcB (creeping water-
bugs), 227, 238

NecturidcB (mud-puppies),
366-368

Necturus maculosus, 366-368

Needham, J. G., 19, 36, 2>7^
115, 150, 195, 201, 234,
287

Needham, J. G., and Need-
ham, P., 24T, 264

Needham, J. G., and William-
son, H. v., 263

Ncniatoda (threadworms) ,
140-141

Nematodes, 100, 103, 139,
140-141

Nepa apiculata, 235-236

NepidcB (water scorpions) ,
227, 235-237

Nets, water, for collecting, 26

Neuronia, 253-254

Netiroptcra (alderflies, dob-
sons, fish-fies), 179, 189,
190, 240-247; aquarium
study, 241 ; form and
habits, 240; key to larvas,
241; occurrence, 240-241;
SialidcF, 241-245; Sisyridce,
241, 245-246

Newts, 207, 353-357; red,
347, 352, 353-357; spotted,

351,353-357
Nitella, 31, 53, 54, 55, 116,

117, 170, 265, 266, 275,

304
"No-see-ums", 292
Nonagria oblonga, 70
Notonecta, 192; irrorata, 237;

undulata, 237

Notonectidce (backs wimmers),

227,237-238
Notropis cornuhis, 335-336
Nymph, definition, 185, 188
Nymphcea advena, 91-93;

micro phylla, 93
NymphcBacece (water-lilies),

91-95

Nymphula, 75, 93, 258; macn-
lalis, 258-259; obliterans,
259-261

Nymphidince, 258

Odonata (dragonflies and
damselflies), 179, 189, 213-
225; ^^schinincE, 218-220;
A nisoptera , 2 1 6-2 2 o ;

Gomphince, 218; LibelhdidcB
216-220; Zygoptera, 220-
225

OdontoceridcB, 255

Oligochcota (bristleworms),

139, 143-147

Oscillatoria, 48

Ostracoda (ostracods), 160,

161, 168
Oxygen, in aquaria, 38, 39,

40; in water, 9; relation of,

to food content of water,

9, 10

Pails, covered, for collecting,

26
PaludicellidcE, 1 3^-1 35
Paludicella ehrenbergii, 134-

135
Paragordius variiis, 142, 143

Paramcecium, 36

Parasites, 141, 153, 175, 178,

230, 231; flatworms, 119;

sponge, 109
Parthenogenesis, Crustacea,

159

Partnerships, animal and

plant, 59
Pectinatella, 131, T33, 137-

138. 165
Pediastrum, 260

Pedicia, 285; albivitta, 289

Pelecypoda, 301-304, 315-

323; SpharidcB, 321-323;

UnionidcB, 320-321

442

INDEX

Pelohatida, 371-373

Peltodytes, 265, 266

Peltroperla, 197

Perca flavescens, 343-344

Perch, 31, 74, 216, 325; com-
mon, 343-344; dwarf, see
daners; yellow, 152, 343-

344
PercidcB, 343-345; see also

perch
Perla, 195, 196; immarginata,

194
PerlidcE, 195
Petromyzon marinus, 327-

329

PetromyzonidcE, 327-329

PhcBophycecB, 47

Phagocata gracilis, 126

PhilapotamidcB, 253

Philodinidce, 129

Philotria, 79

Phryganeids, 253

Phoebe, 25

Photosynthesis, or food mak-
ing, 9

Phryganea, 255; vestita, 254

PhryganeidcB, 249, 253

Phy lactam (zmata, 135

Phyllopoda, 160, 161-162,
161-163

P^3'5a, 74, 302, 303-304;
gyrina, 310-31 1 ; hetero-
stropha, 311

Phy sella gyrina, see Physa
gyrina

Physidae, 3 10-31 1

Pickerel, 31, 74, 216, 338-339

Pickerel weeds, 13, 20, 58,
73, 76, 85-89, 220, 258

Pie plate, white, for collect-
ing, 26

Pike, wall-eyed, 343

Pin, insect, 43

"Pipe-moss", 107

Pipettes, for collecting, 30

Pisidium, 323; politum
decorum, 323; virginicum,

323
Pitcher-plants, 59, 96-98

Placohdella parasitica, 154

Planaria, 1 19-126; aquarium

study, 122-124; food, 122;

form and habits, 119-121;
habitat, 121, 122; identifi-
cation, 124; milky, 122,

125

Planaria alpina, 122; macula-
ta, 121, 122, 125-126

Planarians, Frontispiece, 8,
22, 23, 34, 36, 115, 119-
126, 144

PlanorhidcB, 31 1-3 13

Planorbis, 74, 256, 302; hir-
suliis, 312; trivolvis, 311

Plankton, 22, 49, 294; collect-
ing of, 32-33 ; definition of,
16; organisms, 16, 17; or-
ganisms, reproductive cap-
acity of, 17; population of
lakes, 19

Plant-lice, 70

Plantains, water, 13, 73, 76,
78-79, 237, 279

Plathemis, 217

Plants, collecting, 30; distri-
bution of pond, 12-14;
emergent, 12-13; floating-
leaved, zone of, 13; higher,
58-103; in ponds, 12, 13,
14; in streams and marshes,
20; in rapids, 22; micro-
scopic, 32; simpler (algae),
46-55; water, for aquaria,

39

Plea, 227, 239

Plecoptera (stoneflies), 179,
189, 193-213; PerlidcB, 195-
198; Pteronarcidce, 195; see
also E4>hemerida

Plethodontidce, 362-366

Pleuroceridce, 315

PleiirodelidcB, 353-357

Plumatella,'^iT,4., 135, 136

Pliimatellidce, 135

Podiira aquatica, 191

Pollination, 68 ; arrowhead, 76 ;
pickerel- weeds, 87; pitcher-
plant, 96; water eel-grass,
82 ; white water-lily, 93

Polycentropus, 253

Polygonacece, 89-90

Polygonum amphibium, 15,
89-90

Polyzoa, see Bryozoa

443

INDEX

Pond-lily, small yellow, 93;
white, 58, 93-95, 258; yel-
low, 91-93, 258, 278-279

"Pond-scum", 50

Pond-skaters, 91

Ponds, animal life of, 15, 16,
17; balance of life in, 17, 18;
collecting locality, 30-31,
32, 34, 36; equable temper-
ature of, 8; definition of,

11, 12; kinds, 11-12; lifein,

12, 13; permanent, 12;
plants in, 13, 16; shallow,
16; transient, 11

Pondweeds, 15, 16, 31, 48, 58,
73-75, 100, 303; brown-
leaf, 75; choke, 80; crisp-
leaved, 75; ruffle-leaf, 75;
sago, 75

Pontederia cordata, 85-88

PontederiacecE (pickerel-
weeds) 85-89

Potassium cyanide killing
bottles, 28, 29, 40

Potomanthus, 207

Pools, clear, collecting in, 34

Porifera (sponges), 104-111

Potamogeton, 58, 272, 279,
323; crispus, 75; illinoicn-
sis, 216; natans, 73, 74; pec-
tlnatus, 75

Potato "bugs", 262

Pratt, H. S., Ill

Prawns, 172

Preser\^ation, of specimens,

40-45
Prosimuhuni hirtipes*2g6

Protozoans, 36, 46-54, 55-57,
100, 103, 136, 162; in plank-
ton, 16; in springs, 34

Psephenidce (water-pennies) ,
262, 263, 265, 277-278

Psephenus, 263; lecontei, 278

Pseudacris triseriata, 378

Pseiidosiiccinea columella, see
Lymncsa columella

Pseiidotriton ruber, 363-365

Psilotreta, 255

Pteronarcidce, 195

Pteronarcys, 103, 194; dor-
safa, 193, 194

PtychopteridcB, 282, 287

Pulex aquaticus aborescens,

164
Pidmonata, 307
"Pumpkin seeds", 341-342
Punkies, 282, 290, 292-293
Pupa, delinition, 187, 188

Radicula Nasturtium-aquali-

cum, 95-96
Ramphocoi'ixa acuminata, 226
Rana catesbiana, 387-388 ;

clamitans, 385-386; palus-

tris, 381-382; pipiens, 379-

381; sylvatica, 382-384
Ranatra, 22,6; fusca, 236
Ranidce (frogs), 379-381
Rapids, collecting in, 34; life

in, 22-25
Reading glass, for use in ac-

quarium study, 40
"Red eft", 353-357
"Red lizard", 353-357
Redfins, 335-33^
Reeds, 13, 20, 30
"Reindeer moss", 61
Relaxing jar, 43
Reproductive capacity, of in-
sects, 17, 18
Reservoirs, bryozoans in, 133,

135, 138; sponges in, 107
Rhabdocxlida, 122, 124.
Rhagovelia, 228, 229; obesa,

229-230
Rhamphidia, 289
Rhiniclhys atronasus, 334-335
RhodophycecB, 47
RhyacophUa, 250
RhyacophilidcB, 249-250
Rhyacophilincc, 249-250
RhyncobdellcB, 153
Riccia, 15, 31; fluitans, 60;

natans, 60
Riffle-beetles, 262, 263, 265,

277-278
Riffles, collecting in, 33-34
"Riker boxes", 42, 44-45
Rividaria, 48
Ronald, 199
Rose "bugs", 262
Rotifers, 52, 100, 103, 127-

130, 294; definition, 127;

habits, 129-130; in springs,

444

INDEX

Rotifers — Continued

34; in plankton, 16; struc-
ture, 128-129; tube-dwell-
ing, 15

Sagittaria latifolia, 76-77

Salamanders, 22, 152, 287,
347. 371 ; collecting, 34, 35;
dusky, Frontispiece, 354,
362-363; food of, 302;
giant, 352-353; in vivaria,
40; Jefferson's, 361-362;
killing of, 40; lungless, 362-
366; marbled, 360, 361;
mole, 357-362; mud-pup-
pies, 366-368 ; preserving
of, 41; purple, 366; red,
363-365; red-barked, 347;
spotted, 354, 357-358, 384;
tiger, 358-360; two-lined,
354, 365-366

vSalmon, 325

Salmonidcc (trout), 330-331

Salvelinus, 330 ; fontinalis,
329-33 1 ; malma, 330 ; oquas-
sa, 330

Sandpipers, 287

Sarracenia purpurea, 96-^58

Sarraceniacecc (pitcher-
plants), 96-98

Scaphiopus holbrooki, 371-373

Scapholeheris, 8

Scenedesmus, 260

Schilheodes, 338

Schmidt, J., 332

Scorpions, water, 8, 227, 235-

237
Scuds, 160, 1 68-1 7 1
Season, collecting, 35
Seaweeds, 47
Seed plants, 66-103
Semotilus atromaculatus, 336
SericostomatidcE, 256
Shallows, collecting in, 31-32
Sharp, Dallas Lore, 393
Shells, mussel, 316-317; snail,

304-305
Shiners, common, 335-336
Shrimps, 158, 168-169; fairy,

see fairy shrimps
SialidcB (alderflies, dobsons,

fish-flies), 190, 240, 241-245

Sialis, 189, 241, 244; infuma-

ta, 241-243
Sidesaddle flower, 97
Sieve, or trash net, 30
SiluridcB (catfishes), 337-338
SimuliidcE (black-flies), 283,

296-297
Simulium, 23, 34, 248, 296-

297

Siphlurus, 184, 210, 276

Sisyra, 241, 246

SisyridcB (spongilla-flies), 189,
240, 245-246

Skimmers, 216-218

Smallpox plant, 97

Smartweeds, 89-90; stems,
238

Snails, 8, 15, 19, 21, 22, 23,
26,31,32,34,36,75,77,80,
91, 95, 144, 152, 154, 170,
215,226, 301-315; aquari-
um study, 37, 39, 40, 303-
304; associates, 302-303;
eggs, 308; enemies, 302-
303; form, 304-308; great
pond, 309-310; habitat,
301-302; hairy wheel-, 312;
pond, 306, 308-310; pouch,
310-31 1 ; pulmonate, 307-
310; tadpole, 310-31 1 ;
three-coiled, 311; wheel-,
302-313

Snakes, banded water, 405-
406; collecting of, 28, 30;
colubrine, 405-406; north-
ern water, 404-406

Snow-fleas, 190

Soldier-flies, 283, 299

Sow-bugs, 160, 168, 1 71-172

Sparganiacece (bur-reeds), 70-

73
Sparganium americanum, 73;

eurycarpum, 73
Spatterdocks, 13, 91-93
Specimens, preserving, 40
Specimens, storing of, 41-43;

alcohol, 41; cotton, 42;

envelopes, 42 ; mounting,

42-43; Riker boxes, 42
Sphcericus, 146
Sphceridce (finger-nail clams),

21, 34. 318, 321-323

445

INDEX

Sphagnum moss, 56, 61, 65-
66, 96, 98, 121; pools, 49

Sphcerium, 256, 322; striatum,
322; sulcatum, 321-322

Sphagnacece (sphagnums), 65-
66

Sphere-shells, 256, 322

Spiders, 286

"Spinners", 199

Spirodela polyrhiza, 82-83

Spirogyra, 49, 50, 52, 121,
122, 130, 170, 239, 266, 348

Spirostomum, 56

Sponges, Frontispiece, 32, 95,
104-111, 192, 246; associ-
ates, 109; distribution, 107-
108; fresh water, 15, 36;
habitat, 107-108; identifi-
cation, III; in reservoirs,
107; in waterpipes, 107;
parasites on, 109; preserv-
ing, 41; season, 108; study
and collecting, 109; winter
study, 109-111

Spongtlla, 106; fragilis, 108;
lacustris, 108

Spongilla-flies, 109, 240, 245-
246

Spreading braid, 43-44

Spring peepers, 352, 375-376,
386.

Springs, collecting in, 34

Springtails, 3i» 9i, I79, IQO-
192, 226

Stargrass, water, 88-89

Statoblasts, 132, 133, 138

Stejiostomum, 121; leucops,
124-125

Stentor, 56

Sternotherus odoratus, 393-

394. 396
Stick worms, 247
Sticklebacks, 326, 327, 339-

341; brook, 326, 339-341
Stonecats, 337, 338 _
Stoneflies, Frontispiece, 22,

34, 179, 185, 188, 189, 193-

198, 282; adults, 193-194;

aquarium study, 195; as

food, 243; associates, 195;

habits, 194; nymphs, 193;

parts of, 180-182

Stoneworts, 31, 46, 53, 54
Storage of insects, 42
StratiomyiidcB (soldier-flies),

283, 299
Streams, collecting in, 33, 34;

life in, 20, 21
Streptoneura, 307
Sturgeon, food of, 303
Suckers, 33^-333
Sundews, 98-99
Sunfish, 152, 325, 326, 341-

342; common, 340
Surface, on turtle diet, 398
Surface water, collecting in,

32-33
Swallows, 25

Swammerdam, J., 164

Sympetrum, 217-218

SyrphidcB (syrphus-flies), 79,

282, 299-300
Syrphus flies, 79, 282, 299-

300 ; larvae, 300

TabanidcB (horse-flies), 283,
298-299

Tabanus, 299; atratus, 299

Tadpoles, 12, 30, 35, 39, 41,
116, 152, 170,270,271,275,
347, 348, 349, 350, 352

TcBfiiopteryx, Frontispiece ; ni-
valis, 197, 198

TanyderidcB, 287

Tape worms, 119

Temperature, of water, 8-9

Tenspots, 216-217

Testudinata (turtles), 389-
404; Chelydridce, 391-393;
KinosternidcB, 393-397 ; Tes-
tudinidcB, 397-402; Triony-
chidcB, 402-404

TestudinidcB (pond and land
turtles), 397-402

Threadworms, 1 39-141

Thrips, 95

Tiger-beetles, food of, 17;
larvae of, 15

Tipiila abdominalis, 34, 289

TipulidcB (craneflies), 283,
287, 288-289

Tipuloidea (craneflies), 283-
289; PtychopteridcB, 287-
288; TipulidcB, 288-289

446

INDEX

Toads, 347-352, 368-373;
American, 368-370, 384;
burrowing, 371-373; col-
lecting, 35; Fowler's, 369,
370-371 ; hermit spadefoot,
371-373; spadefoot, 371-
373; tree, 373-375- 3^6

Tools, collecting, 26-30

Torre-Bueno, J. R. de la, 233

Trembley, Abbe Abraham,
116

Tricznodes, 95, 192, 255-257,
276

Trichoptera (caddis flies) , 179,
190, 247-257; Hydroptili-
dcB, 249 ; Hydropsychidce,
251-253; LeptoceridcB, 254-
255; LimnophilidcB, 256;
MolannidcB, 254; Odonto-
ceridcB, 255; PhilopotamidcB,
253; PhryganeidcB, 253-254;
RhyacopkilidcB, 249-251;
SericostomatidcB, 256-257

Triclada, 124, 125

Tricorythus, 33, 185, 187, 210

TrionychidcB (soft-shelled tur-
tles), 402-404

Triturus, 36; viridescens, 351,

353-357
Tnvolvis parvus, 312

Tropisternus, 277; lateralis,
277

Trout, 152, 286, 329, 330-331 ;
brook, 303, 334; "Dolly
Varden", 330; lake, 334;
Rangley Lake, 330

Tube worms, 144

TubicidcB (bloodworms), 144

Tubifex, 16, 33, 144, 145, 146,
147, 292

Turbellarians, 1 19-126; aqua-
rium study, 122-124; food,
122; form and habits, 119-
121, habitat, 121-122; iden-
tification, 124-126

Turtles, 3, 33, 119, 154, 156;
as food, 17; box, 393-397;
breeding habits, 390; col-
lecting of, 28. 31, 35; food,
302, 390; habitat, 390; life
history, 391 ; mud, 394-397;
musk, 393-394. 396;

painted, 264, 397-399, 400
pond, 324; pond and land
397-402 ; preserving of, 1 1
sculptured, 399-402; snap
ping, 391-393; soft shelled
402-404 ; spiny soft-shelled
402-404; spotted, 31, 398
39^, 400; turtle leech, 154
wood, 399-402

Typha angustifclia, 70; lati
folia, 68-70

TyphacecB (cat-tails), 68-70

Unio complanatus, see Ellip-

tio complanatus
UnionidcB (pearly mussels)

320-321
Utricularia, 15, 52, 164, 167;

vulgaris, 100-103

Vallisneria, 39; spiralis, 80-

82
Valvata, 302; tricarinata, 314
ValvatidcB, 315
VeliidcB (broad-shouldered

water striders), 228, 229-

230
Venus' flower basket, 104
"Vermilion spotted newts",

355

Vials, for specimen storage,

41-42
Vivaria, 40

Vivipara contectoides, 315
ViviparidcE, 315
Volvox, 49, 50
Vorticella, 46, 52, 56-57f 136

Ward and Whipple, 1 1 1
Water, and living things, 7;
density of, gives support,
8; environment, 7-8; food
content, 9-10; light in, 10;
poor conductor of heat, 8;
temperature of, 8-9 ; trans-
porting agent, 8
"Water-bloom", 48
Water boatmen, 227, 239-240
Water bugs, 11-12, 179, 188,
189, 225-240; aquarium
study, 226-227; associates,
226; backswimmers, 36,

447

INDEX

Water bugs — Cofitmued

227, 237-238, 244; creep-
ing, 227, 238-239; electric
light bug, 233-234; food,
226; giatit, 227, 232-235,
302; habits, 225; identiii-
cation, 227-228; larvae, 15;
pigmy, 227, 239; water
boatmen, 239-240; water-
measurers, 227, 228-229;
water scorpions, 227, 235-
237; water striders, 7-8,
228-232, 262

Water-cress, Frontispiece, 95-
96

Water-dog, see mud-puppy

Waterfalls, collecting in, 34;
life in, 25

Water-fleas, 3, 160, 161, 164-

165

Water-hoppers, 166

Water-hyacinth, 20
Water-lily, 11, 15, 16, 31, 35, >

91-95, 100, 228; white, 58,

93-95. 192, 258; yellow, 58,

91-93, 258, 278-279
Water-measurers, 227, 228-

229
Water-mites, 15, 30, 52, 95,

175-178, 192,230-231,257;

aquarium study, 176; form,

175; habits and habitat,

175; identification, 176-

178; preserving of, 41; red,

239; season, 176
"Water moccasin", 404
Water-net, 26, 31, 32, 33
Water-pennies, Frontispiece,

25, 34, 184, 195, 262, 263,

278
Water pipes, bryozoans in,
^ 135; sponges in, 107
Water scavenger beetles, 264,

273-277; adults, 274; eggs,

274; larvae, 274
Water scorpions, 227, 235-

237
Water skaters, see ivater

striders
Water striders, 7-8, 228-232,

262; broad-shouldered,

229-230

Water- weeds, 79-80
Weather, effect on collecting,

35

Wetmore and Harper, 397
Wheel animalcules, 127-130
Whippoorwill's shoes, 96
Whirhgig beetles, 11, 36, 91,
192, 226, 262, 263, 264,
271-273; larvae, 272; pupai,

273
"White-gloved howdy", 201,

209-211
White heel-spitter, 301
Whitetails, 217
Wild celery, 80-82
Wilder, I. W., 363
Wilson, C. B,, 216, 272, 273,

275, 277

Wire worms, see hairworms

Wolffiu, 82; Columbiana, 85

Woodcocks, 287

Woods, W. C, 214

Worms, 16, 91, 154, 156, 157,
158, 216; annulated or
"ringed", 143-144; "blood-
worms", 144, 286, 292;

bristle, 139-140, 1 43-147;
earthworms, 139, 143, 145;
fiatworms, 1 19-126; hair-
worms, 139-140, 141-143.
in lakes, 20; in springs, 34;
nematode, 140-141; oligo-
chaete, 139, 143-147; plant-
eating, 13, 14; preserving
of, 41; segmented, 148;
tapeworms, 119; thread-
worms, 139-141; tube-
worms, 144
Wright, A. H., 361, 374, 382,

397

Wright, A. H., and Allen, A.

A., 378

Yellowstone Park, alga^ in

Hot Springs, 48
Yerkes, R. M., 399

ZaitJia fluminea, 233
Zoochlorcllae, 108
Zooecia, 133
Zygnema, 50
Zygoptera, 220-225

448

i

I