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THE FROG BOOK
THE NATURE LIBRARY
AMERICAN ANIMALS
Witmer Stone and Wm. Everitt Cram
AMERICAN FOOD AND GAME FISHES
David Starr Jordan and Barton W. Evermann
NATURE'S GARDEN
BIRD NEIGHBORS
GAME BIRDS
BIRD HOMES
THE BUTTERFLY BOOK
THE MOTH BOOK
THE INSECT BOOK
THE MUSHROOM BOOK
THE TREE BOOK
THE FROG BOOK
Neltje Blanchan
Neltje Blanchan
Neltje Blanchan
A. R. Dugmore
Dr. W. J. Holland
Dr. W. J. Holland
Dr. Leland O. Howard
Nina L. Marshall
Julia E. Rogers
Mary C. Dickerson
THE FROG BOOK
FRONTISPIECE — COLOR PLATE I
COLOR PLATE I
THE COMMON TREE FROG \Hyla versicolor LeConte]-
In and about the ponds in May. Jack-in-the pulpit means to him
convenient shade and a comfortable seat.
THE FROG BOOK NORTH
AMERICAN TOADS AND FROGS
WITH A STUDY OF THE HABITS
AND LIFE HISTORIES OF THOSE
OF THE NORTHEASTERN STATES
BY
MARY C. DICKERSON
Author of "Moths and Butterflies'
WITH OVER THREE HUNDRED PHOTOGRAPHS
FROM LIFE BY THE AUTHOR
N A
NEW YORK
DOUBLEDAY, PAGE & COMPANY
1906
Copyright, 1906, by
Doubleday, Page & Company
Published, July, 1906
All rights reserved,
including that of translation into foreign languages,
including the Scandinavian.
PREFACE
THE original manuscript for this book concerned Toads and
Frogs of Northeastern North America only. It was
compiled largely from notes made during a period of
some ten years in Minnesota, Michigan, Tennessee, New Ham-
shire, Massachusetts and Rhode Island. It was written with
the direct aim of making these forms known and appreciated by
people interested in nature.
Brief accounts of the species of other parts of North America
were added later. These descriptions and the photographs
accompanying them were made from living material shipped from
various parts of the continent. This collection of material is in
the American Museum of Natural History, New York, with the
exception of specimens of Colour Plates XI and XVI which are
in the National Museum at Washington.
The Colour Plates were made from photographs from life,
some of the plates representing eight or ten negatives. They
were coloured from living material by Mr. Herbert L. Guild of
Providence, working under the supervision of the author Owing
to the careful work of Mr. Guild on the originals and to the efforts
of the Publishers to obtain accurate reproductions, these plates
are unusually true to life. Of course, in many cases, the colour
represented may be only one phase in a complex and changing
colouration.
Twelve black and white plates showing typical haunts of
common toads and frogs are from photographs by Mr. W. A.
Dean, Artist Photographer of Providence. Various line drawings
introduced to indicate food or enemies or to act as a calendar,
were made by Miss Alma Field of Providence. With few ex-
ceptions the subjects for these line drawings were taken from
photogiaphs from life by the author.
Sincere gratitude is especially due to three people: Dr. J.
Percy Moore of the University of Pennsylvania, Philadelphia,
PREFACE
who read the manuscript and gave many valuable suggestions;
Dr. Leonhard Steineger of the National Museum at Washington
who not only allowed study of the National Museum Collection
of Salientia but also gave assisrance in the identification of speci-
mens; and Miss Maud Slye, Instructor in the Rhode Island
Normal School, Providence, who read the manuscript from ihe
standpoint of its English.
Thanks aie due to many others also, for help in getting
living material, for opportunities for study and so on. Among
these are Dr. Frank R. Lillie, University of Chicago; Dr Wm.
M. Wheeler, American Museum of Natural HisiOiy, New York;
Dr. Hans Gadow, University of Cambridge, England; Director,
C. H. Townsend, New York Aquarium; Dr. A. D. Mead, Brown
University, Providence; Dr. J. Van Denburgh, California Acad-
emy of Science, San Francisco; and Dr. J. F. Illingworth, Seattle,
Washington.
It is hoped that the book not only will introduce the ele-
mentary nature student to the fascinations of pond life but that
it will suggest to the more advanced student serious work on the
classification, life histories and habits of the North American
Salientia — for there remains a field of work of such breadth ihat
what has been done seems only a beginning.
MARY C. DICKERSON
Providence, R. I.
June 10, 1906.
LIST OF COLOUR PLATES
COLOUR PLATE
I. • ...... Frontispiece
FACING PAGE
11- . . . . . . . . . .50
64
IV. . ....... 90
V. ...... i 08
VI. 116
VII. 130
VIII 132
*v • • . . . . . . . . .i 40
•y i
^*- * • ......... I y 2
XII 1 86
XIII. . . . . . . . . . 198
XIV. .......... 204
•«*• v. . . . « . . . . . 214
XVI. ........ 218
/ )f i- H
LIST OF HALF-TONES
PLATE FACING PAGE
I Figs. 1-3. The SPOTTED SALAMANDER (Amblystoma
punctatum Linn): spherical eggs; full grown
larva; spotted salamanders, i year old . . 4
II "In May, when birch trees are in their splendour of
leaves, frogs and toads announce spring from all
the waterways" 5
I 1 1 Fig. 4. Diagrams showing location of lateral line sense
organs in dorsal and side views of Bullfrog tadpole 6
IV Figs. 5-6. Diagrams showing ventral views of shoul-
der girdles and dorsal views of pelvic girdles . . 7
V Fig. 12. Explains fundamental structural character-
istics mentioned in keys 42
VI Figs. 13-16. Scaphiopus bolbrookii Harlan : skin of
side and upper arm; unbroken curve of jaws; black
horny thickening of first and second fingers . . 43
VII Figs. 17-19. Scaphiopus bolbrookii Harlan: pro-
portions of body and leg; elevation of eye; webbed
foot 56
VIII Figs. 20-25. Scaphiopus couclii Baird: natural
positions and structural characteristics . . 57
IX Figs. 26-30. Scaphiopus h.bombijrons Cope: vertical
pupil; shape of head; smooth skin; development
of inner sole tubercle 62
X The Toads in the pond. "May ist — The spreading
leaves of the skunk cabbage and the unrolling
fronds of the cinnamon fern" .... 63
XI Fig. 32. Toads in artificial pond. Fig. 33. Toads'
eggs laid June 12, 1903, and photographed 24
hours later 66
XII Fig. 34. Toads' eggs three days after laying. Fig.
35. Toad tadpoles hatched four days after eggs
are laid 67
XIII Fig. 36. Coiled mass of toads' eggs. Fig. 37. Black
toad tadpoles ....... 70
Vll
List of Haif-Tones
PLATE FACING PAGE
XIV Figs. 38-39. Formation of the toad from tad-
pole: legs and arms appear; tail becomes
shorter. Fig. 40. "Just toads." Fig. 41.
Toads playing dead. Fig. 42. I year old
toads .... ... 71
XV Fig. 43. Drawing of the toad's moulted skin 74
XVI Fig. 44. Right foot of the toad showing webs
and spur. Fig. 45. Toads still retain a de-
sire to sing in July and August. Fig. 46.
Portion of a toad's moulted skin ... 75
Figs. 47-48. The AMERICAN TOAD: views of
back and bony crests of the head ... 78
j- Figs 50-56. The Food of the Toad . 79 and 82
Fig. 57. More of the toad's food; the gray slug
and its eggs 83
Fig. 58-60. How the toad eats a worm . . 86
Fig. 61. Resemblance of toad's skin to garden
earth. Fig. 62. Structure study of under-
surface of American Toad .... 87
Fig. 63. Toads go to their native ponds imme-
diately after hibernation .... 88
Figs. 64-67. The SOUTHERN TOAD (Bufo lentigi-
nosus Shaw) : structural characteristics; — i.e.,
size of eye, ear and parotoid glands; elevation
of crests; arrangement of bony crests of head 89
XXV Figs. 68-70. The ROCKY MOUNTAIN TOAD (Bufo
I. woodhouseiGirard) : large, rough-skinned toad;
unusually short head; structure of under parts;
crests of the head; texture of skin of upper sur-
face . 92
XXVI Figs. 71-74. The ROCKY MOUNTAIN TOAD: study
of foot; contrast of colour; character; study
of head 93
XXVII Figs. 75-78. Bufo fowleri Putnam; character-
istics of under parts; eggs laid in long strings;
spotted character of toad .... 94
XXVIII Fig. 79. When roughly handled the toad "plays
XVII
XVIII
XIX
XX
XXI
XXII
XXIII
XXIV
VI11
List of Half-Tones
PLATE FACING PAGE
dead," even breathing movements are sus-
pended. (Bufo fowleri, female.) Fig. 80.
"Ready for new emergencies." Fig. 81. Pro-
tective resemblance of FOWLER'S TOAD . 95
XXIX Figs. 82-84. FOWLER'S TOAD; study of hand
and foot; vocal pouch; texture of skin;
parotoids and cranial crests ... 98
XXX Fig. 85. Structure study of hand and foot of
Bujo cognatus. Fig. 86. Defensive. Fig.
87. Ready for emergencies ... 99
XXXI Figs. 88-89. Buf° ^gnatus Say; structural
characteristics of under surface; identifica-
tion characteristics of bony crests of head,
of parotoids, etc. 100
XXXII Figs. 90-92. Bujo cognatus Say: intricate pat-
tern of lines on back; short head; length of
foot; comparison of striped and spotted toad 101
XXXIII Figs. 93-95. Bufo compactilis Wiegm: instincts
for hiding and burrowing; study of hand
and foot; parotoid glands; warts on upper
surface 102
Figs. 96-98. Studies of Bufo compactilis
Wiegm. Figs. 99-100. Bufo cognatus Say;
vocal bladder 103
Figs. 101-106. The OAK TOAD (Bufo querci-
cus Holbrook) : bony crests of head ; arrange-
ment of light and dark colour on upper
parts; covered with small warts; structure
study of underparts 104
XXXVI Figs. 107-109. Bufo olvarius Girard: texture
of skin, parotoid glands, cranial crests and
other identification points . . . .105
XXXVII Figs, iio-iu. Bufo alvarius Girard: studies
of palm and foot 106
XXXVIII Figs. 112-113. Bufovalliceps: outline of jaw,
texture of skin of under parts and structure
of hand 107
XXXIX Fig. 114. Bufo valliceps Wiegm: structure
study of upper surface. Fig. 115. Bufo
XXXIV
XXXV
IX
List of Half-Tones
PLATE
XL
XLI
XLII
structure study of foot
FACING PAGE
sole
XLI 1 1
XLIV
XLV
XLVI
XLVII
XLVI 1 1
XLIX
L
LI
LI I
113
114
valliceps
tubercles ....... no
Figs. 116-120. Studies of Bufo punctatus Baird
and Girard ....... HI
Figs. 1 21-122. The CALIFORNIA TOAD (Bufo hal-
oplilus Baird): colour; warts; structural char-
acteristics of head ..... 112
Figs. 123-126. Bufo halophilus Baird: studies
of spotted under parts; web of foot; sole tu-
bercles; vertebral streak; warts; glandular
elevations on tibia ......
Figs. 127-130. Bufo haloplilus Baird: skin
texture; outline of head; size of ears, structure
of hand and foot, and other identification
characteristics .......
Figs. 131-133. Bufo boreas Baird and Girard:
size; structure of concealed parts; various char-
acteristics of identification . . . .115
The COMMON TREE FROG (Hyla versicolour) makes
his home in the trees along forest paths, as well
as in those about the house and in the orchard 1 18
Figs. 134-137. The COMMON TREE FROG (Hyla
versicolour Le Conte): conspicuous markings 119
Figs. 138-142. Studies of the COMMON TREE
FROG (Hyla versicolour Le Conte) . . .122
Figs. 143-146. (Hyla arenicolour Cope): struct-
ural characteristics; colour; rough character of
skin of the under parts; web and sole tubercles 123
Figs. 147-150. The FLORIDA TREE FROG (Hyla
gratiosa Le Conte): structure study of under
parts and upper surfaces . . . .124
Figs. 151-153. The FLORIDA TREE FROG (Hyla
gratiosa): throat pouch partially extended and
sound asleep ....... 125
Figs. 1 54- 1 60. Studies of the GREEN TREE FROG
(Hyla cinerea Daudin) ..... 126
Figs. 161-164. Studies of Hyla evitatta Miller.
A smooth skinned, plain green tree frog, closely
related to Hyla cinerea ..... 127
List of Half-Tones
PLATE FACING PAGE
LI 1 1 Figs. 165-169. Hyla regilla Baird and Girard:
the skin; eggs laid in clusters; vocal pouch and
other structural characteristics . . . 138
LIV "Most of the SPRING PEEPERS live on the ground
in the woods throughout the year except for
a few weeks in early spring, when they are
to be found in the ponds and the marshes
adjacent." 139
LV Figs. 170-172. Habits of Hyla pickeringii Storer, 148
LVI Figs. 173-177. Studies of The SOUTHERN TREE
FROG (Hyla squirella Bosc) : a delicate, smooth-
skinned little tree frog, one of the most active
in North America 149
LVII Figs. 178-183. Smilisca baudinii: changes from
nearly black to delicate light green or fawn
colour; fingers with slight webs; structure study
of under parts 152
LVI 1 1 Fig. 184. Studies of the CRICKET FROG (Acris
gryllus Le Conte). Fig. 185. Studies of the
SWAMP TREE FROG (Cboropbilus n. feriarum
Baird) 153
LIX Figs. 186-187. LitbodyteslatransCope. Fig. 1 88.
Liibodytes latrans: characteristics of under
surface 164
LX Figs. 189-192. Engystoma carolinense Holbrook.
Fig. 193. Engystoma texense Girard . .165
LXI Figs. 194-196. Hypopacbus cuneus Cope: fat
squat body; fold of skin on the top of head
back of eyes; structure of hand and foot; ver-
tebral streak; arrangement of spots and bands
of black on upper surface . . . .170
LXII "The LEOPARD FROG lives in meadows and fields
adjacent to brooks and marshes" . . .171
LXI 1 1 Figs. 197-199. LEOPARD FROGS (Rana pipiens
Shreber): structure study of hand and foot;
typical young LEOPARD FROGS . . . . 1 76
LXIV Figs. 200-201. Characteristics of the COMMON
LEOPARD FROG (Rana pipiens Shreber) . . 177
LXV Development of the LEOPARD FROG'S EGG . .178
xi
List of Half-Tones
PLATE
LXVI
LXVII
LXVI 1 1
LXIX
LXX
LXXI
LXXII
LXXIII
LXXIV
LXXV
LXXVI
LXXVII
LXXVI 1 1
LXXIX
LXXX
FACING PAGE
Figs. 208-21 1. Growth of the LEOPARD FROG
TADPOLE 179 and 180
Early July. "The border of the pond where the
young Leopard Frogs develop among the
pickerel weeds and water lilies." Fig. 212.
The LEOPARD FROG protected by resemblance
to grass and clover 181
Figs. 2 1 3-2 1 6. Studies of the SOUTHERN LEOP-
ARD FROG (Rana spbenocephala Cope) . .186
Figs. 217-218. The COMMON LEOPARD FROG
(Rana pipiens Shreber): head more or less
pointed; blotch at centre of ear; dark spot on
head in front of eyes. Figs. 219-220. The
SOUTHERN LEOPARD FROG (Rana splenoce-
pbala Cope): structure of head; length and
other structural characteristics . . .187
"The brook and the meadows near by make the
home of the Pickerel Frogs" . . . .188
Figs. 221-222. Studies of PICKEREL FROGS
(Rana palusiris Le Conte) . . . . 1 89
Rana areolata Baird and Girard: charac. points 192
Figs. 226-228. Structural characteristics of
Rana czsopus Cope 193
Figs. 229-234. Studies of the GREEN FROG . 200
Figs. 235-241. Metamorphosis of the GREEN
FROG (Rana clamitans Latr) . . . .201
"The home of the WOOD FROG (Rana sylvatica
Le Conte)" 206
Figs. 242-245. Studies of the WOOD FROG
(Rana sylvatica Le Conte) . . . .207
Figs. 246-247. Eggs of the WOOD FROG. Fig.
248. Hatching WOOD FROG TADPOLES. Fig.
249. SALAMANDER (Amblysioma opacuni) eggs
fastened to oak leaf. Fig. 250. The WOOD
FROG leaves the pond while the bepatica is
still in bloom 212
Figs. 251-254. Structure studies of Rana dray-
ionii Baird and Girard: foot; length of fin-
gers; size and arrangement of spots . . 213
XII
List of Half-Tones
217
220
221
226
PLATE FACING PAGE
LXXXI Figs. 255-256. Rana draytonii Baird and
Girard: eight or more years old . . . 216
LXXXI I Fig. 257. Rana onca Cope. Figs. 258-259.
Rana aurora Baird and Girard: structure
studies
LXXXIII Figs. 260-263. Structure studies of Rana pre-
tiosa
LXXXIV Figs. 264-266. Structural characteristics of
Rana boylii Baird and Girard. Figs. 267-268.
Rana virgatipes Cope: outline of head; size
of eye and ear; length of foot; relative
proportions of body and leg; markings of
under parts
LXXXV Figs. 269-271. The SOUTHERN BULLFROG
(Rana grylio Stejneger): beautiful frog; me-
tallic green on head and shoulders; long
narrow head ; smooth undersurfaces of fin-
gers and toes
LXXXVI Figs. 272-274. Rana grylio: toes long; head
pointed; eyes greatly elevated; texture of
skin; relative size of eye and ear; fold of
skin from eye to shoulder ....
LXXXVI I Fig. 275. Under the pickerel" weed. The
BULLFROG is the most aquatic frog of North-
eastern North America (Rana catesbiana
Shaw)
^XXXVIII June. "We are likely to hear and see BULL-
FROGS if we go rowing on river or pond.
BULLFROGS prefer large ponds where the
water is screened from the shore by willow,
alder and other water loving plants "
LXXXI X Figs. 276-277. Studies of the BULLFROG:
spots of the back; ear; fold of skin extend-
ing backward from the eye, around the ear
and down to the shoulder ....
XC Fig. 278. The BULLFROG is heard in the
ponds by the first of May. Rana catesbiana
Shaw, Wisconsin
XCI Fig. 279. Drawing to show the floor and roof
227
228
229
232
233
Kill
List of Half-Tones
PLATE FACING PAGE
of the Bullfrog's mouth. Fig. 280. BULLFROG
TADPOLE, one day previous to the time of activity
of the arms 234
XCII Fig. 281. Hand of a BULLFROG. Fig. 282. Foot
of a BULLFROG. Figs. 283-284. Studies of the
BULLFROG TADPOLE 235
XCII I) Figs. 285-289. Development of the BULLFROG
XCIV f TADPOLE: right arm breaks through skin; ab-
sorption of tail begins; legs do all the work of
swimming; comfortable out of water; constantly
rushes to surface for air; tail merely a black
stub 236 and 237
XCV We have waded there for lilies or fished from its
sheltered coves for pickerel, or perhaps for frogs." 238
XCVI Fig. 290. "The BULLFROG — independent, self-com-
posed, alert — is the spirit of the place" . . 239
sav
LIST OF TEXT ILLUSTRATIONS
PAGE
Fig. 7. The Common Tree Frog, (i) in resting position
with lungs inflated and body large, and (2)
singing, the air from the lungs forced into the
throat vocal pouch 19
Fig. 8. Bufo compactilis with vocal bladder extended from
base of throat 20
Fig. 9. Leopard Frog, drawn to show vocal pouches ex-
tended at the shoulders 20
Fig. 10. When the pigment cells retreat and contract, the
resulting colour of the skin is light . . 22
Fig. ii. When the Pigment cells send out interlacing
branches, the resulting colour is dark. After
Lister 23
The unrolling fronds of the Cinnamon Fern . . 64
The shining leaves and flowers of the " Cowslips,"
May ist 65
The broad leaves and flower-like fruits of the
"Cowslips." May 2oth 65
Late June. The little Toads leave the ponds when
the Arrowhead begins to bloom ... 70
Fig. 49. To show the movement of the toad's tongue in
catching an insect. The tongue is fastened in
front instead of at the back and can be extended
fully two inches, in an exceedingly rapid move-
ment. Its surface is sticky . . . .81
The toad eats the black crickets that are said to
damage the strawberry crop .... 82
The wingless grasshopper (Ceuthophilus) of the
ground 82
In May when apple trees are in bloom the Common
Tree Frog is at the pond 120
When Jack-in-the-pulpit appears we may expect
to hear the trilling of Hyla versicolour from pond
and river margins 121
XV
List of Text Illustrations
PAGE
March first. Spring Peepers begin calling when
the pussy willows are gray . . . .140
Late March. Spring Peepers are singing both day
and night when the pussy willows are in blossom 141
The middle of April. When pussy willow seed
pods are ripening, Spring Peepers are calling only
during the late afternoon and night . . . 142
Early May. The chorus of Spring Peepers closes
as the pussy willow is scattering feathery seeds 144
The chorus of Spring Peepers begins when the blue
violets of the marsh are first opening, and closes
when these violets are struggling for light among
rank growths of fern and hellebore . . . 145
Pickering's Hyla is still calling in the woods, when
the witchhazel's yellow flowers appear . . 147
The maroon hoods of the skunk-cabbage are pic-
turesque among moss and dead leaves at the
time when the eggs of the Leopard Frog are
laid 175
Fig. 204. Series of diagrams to show cleavage of the frog's
egg. The second very nearly corresponds to
Fig. 202. The third represents Fig. 203. The
last is a stage just preceding that of Fig. 205
in which the cells are too small to be seen.
(After Ecker) 177
A narrow escape from the jaws of the water-tiger 182
What are apparently /green stems come to life and
send out powerful arms to capture the tadpoles 182
The back-swimmer is a powerful enemy of the young
tadpoles 183
Late March. The Leopard Frogs are croaking in
the pond when the blue-birds are deciding on
a home 1 84
July. The Leopard Frogs eat the young grass-
hoppers that are so thick in the grass . .185
The Pickerel Frogs are croaking when the blue
flags are in bloom 189
The Green Frog comes from his winter sleep soon
after the redwings appear in the marshes . 200
XVI
List of Text Illustrations
PAGE
Green Frogs may catch the dragon flies that have
left their larval skins 201
The Green Frog captures the damsel-flies before
their wings are dried 202
Green Frogs feed upon the fairy shrimps of icy
March pools 203
In June the Wood Frog is found where the fra-
grant pyrola stands on its carpet of oak leaves
and pine-needles 206
The waxy flowers of the pipsissewa. June . . 207
Like the chickadee, the Wood Frog is a gentle
spirit of the woods .211
XVll
INTRODUCTION
I. Distinction of Batrachians from Fishes and Reptiles
The Batrachians represent a Class of Vertebrate animals
occupying a position between Fishes and Reptiles. There is con-
siderable variation in general appearance among the different
living members of the Class, so that a Batrachian is not as easily
defined and identified as is a fish, a bird, or a mammal. There
is no one characteristic by which it may be known, as there is
in each of these other Classes.
Batrachians, however, are distinguished from Fishes by sev-
eral easily recognizable characteristics. They usually have paired
limbs furnished with fingers and toes (pentadactyle limbs), and
never have fins stiffened by bony rays (although they may have
fins soft and filmy in character in the young stages). With the
exception of one order (Apoda), they do not have scales, but pos-
sess a skin either smooth and slimy or rough with warts and
nearly dry. Fishes breathe throughout their lives by means of
gills, but the Batrachians, while usually living in the water and
breathing by gills in the early stages of life, as a rule breathe
during adult life by means of lungs, and are more or less well
developed for land life.1
A popular distinction from the Reptiles is not easily made,
since Batrachians and Reptiles sometimes correspond almost ex-
actly in form. That is, they both have limbs of the pentadactyle
type and in the case of Salamanders (Batrachians) and Lizards
(Reptiles) both possess tails and elongated bodies. In fact, some
of the common Salamanders are popularly called Lizards, show-
ing the great superficial resemblance of certain members of the
two Classes.
However, Batrachians and Reptiles are very different indeed
in all fundamental points. Instead of a more or less smooth and
slimy skin, Reptiles have a skin protected by overlapping scales,
'There are certain technical points of difference in characteristics of the skeletons; i.e., the
vertebrae of Fishes are never pseudocentrous or notocentrous. The Batrachian has two occipital con-
dyles, except in the case of some Stcgocephali. The Batrachian is characterized by the presence of a
fenestra ovalis and stapes and by internal nares.
Introduction
as in the case of Snakes and Lizards; like the Turtles, possess a
bony box-like shell; or like the Crocodiles and many extinct forms,
have bony plates in the skin. Unlike the Batrachians, the Rep-
tiles breathe throughout their lives by means of lungs — in cer-
tain cases helped by the walls of the pharynx — and when adapted
in other ways for water life, remain divers merely.
Batrachian eggs are laid in the water and hatch into so-called
tadpoles, different from the adults in appearance and thoroughly
adapted for water life. The eggs of Reptiles are laid on land, and
they hatch into perfected diminutive Reptiles fully adapted for
land life.1
II. Two Orders of Living North American Batrachians — Urodela
and Salientia
The living North American Batrachians differ enough to al-
low classification into two distinct Orders, the Urodela and the
Salientia. The Urodela are the Tailed Batrachians, or Salaman-
ders, with various popular names, such as Mud Puppies or Water
Dogs, Tritons, Newts, and Efts. The Salientia are the Tailless
Batrachians, i. e. the Toads, Tree Frogs, Frogs, and all Batrachians
that have the frog-like form.
There can never be any confusion in identifying a Batra-
chian as a member of one or the other of these two Orders. The
Urodele is always tailed, has an elongated body and legs of nearly
equal size; while any member of the Salientia has a relatively
short stout body without a tail and with the long hind legs de-
veloped for jumping and swimming.2
The members of the Order Urodela vary considerably in
their habits and life histories. Like all the Batrachians, they
usually pass through a larval aquatic existence, after which they
1 The technical differences in the skeletons are as follows:
The vertebrae of Reptilia are gastrocentrous, those of Batrachia never so; Batrachian skeleton
never has sternal ribs and a true sternum; Batrachia have two occipital condyles for the articulation
of the skull with the vertebral column, Reptilia have only one.
2 Technical differences of the skeletons are as follows:
The acentrous and opisthoccelous.or amphiccelous vertebras of the Urodela are many in number.
The trunk vertebra? carry ribs or vestiges of them. The shoulder-girdle is simple, mainly cartilagi-
nous, and not a complete circle — the precoracoids not meeting in the midventral line. The pelvic
girdle is weak, with the ilia placed at right angles to the axis.
The Salientia have few vertebrae, which are usually notocentrous and proccelous; the last bone
of the vertebral column (Fig. 6) is a long solid coccyx to give support to muscles for leaping. This
coccyx consists of several vertebral segments coalesced. The pelvic girdle is large and strong; ribs
are absent except in Discoglossidas. The shoulder-girdle is a complete circle' overlapping or fusing
in front. (See Fig. 5.)
Development
may remain aquatic or may become terrestrial in habit. (Figs, i,
2, and 3.) The aquatic forms usually have the tail flattened
vertically to aid in swimming; while the terrestrial forms have
a rounded tail. A few, like Necturus, keep the gills throughout
their lives.
The Urodela represent in numbers about one-tenth of the
Batrachian group as known in the world at present, that is, about
one hundred species. Of this number between sixty and seventy
are American species.
III. Development and Metamorphosis
The North American representatives of the Salientia deposit
the eggs in water, usually in shallow, stagnant water. The eggs
may be laid singly or in small clusters, as in the case of some
of the tree frogs (Fig. 167); in large masses, as is the habit among
the frogs (Fig. 246) ; or in long unbroken strings, as in the case of
toads (Fig. 34). The eggs are sometimes free in the water, but
more often are attached to water-weeds or other objects. If free,
the egg mass has such buoyancy that it floats at the surface of
the water (Rana sylvatica}.
The number of eggs in a laying depends on the species and
often on the age and size of the individual of the species. The
number may be as high as 12,000 in the American Toad. The
size of the egg will sometimes help in the identification of a
species, but there is great variation in this respect. In the first
place, the size of the egg does not correspond with the size of the
Batrachian, the largest frog of North America (Rana catesbiana)
having an egg of less size than that of some of its smaller relatives.
Besides, the size varies considerably with the individual. In a
large collection of egg masses of Rana sylvatica or Rana palustns,
the difference in size will be so conspicuous that unless one
knew the opposite to be true, he would judge the egg masses to
have been laid by frogs of different species.
The egg is spherical, and is provided with a large amount of
light-coloured yolk. When the eggs are first laid, part of this
yolk can be seen occupying the lower portion of the egg under
the more or less pigmented upper portion. (Fig. 202.) The dark
pigmented portion of the egg at the top (later the whole surface
becomes black or brown in colour) allows a greater absorption
of the sun's heat than would a lighter colour. So the develop-
3
Introduction
ment which is wholly dependent on temperature is materially
aided. Each egg is surrounded by a thin elastic membrane that
fits it closely (except in Pelobatidae) and one or two gelatinous
membranes outside of this. These membranes are not visible
when the eggs are first laid, but swell after they come into con-
tact with water, becoming very conspicuous, though transparent.
These envelopes aid the development; they absorb and hold the
warmth from the sun's rays, producing a somewhat higher and
more equable temperature than is that of the surrounding water.
They also serve to protect the egg or egg mass by converting it
into a slippery unmanageable object not easily grasped and eaten
by birds, turtles, and others of the Batrachian's enemies about
the pond. It is reported that ducks sometimes feed upon frog
egg masses. The membranes of the eggs are easily penetrated
by leeches,1 which suck out the contents, and so prove themselves
perhaps the most destructive enemy of frog spawn.
The breeding season is likely to occur in early spring, but
varies with the species, some of the Salientia being able to en-
dure more cold than others. As a rule, toads are later in their
appearance at the pond than are frogs or tree frogs. In eastern
North America, Rana sylvatica and Rana pipiens appear earliest
among the frogs, Hyla pickeringii and Chorophilus n. feriarum
among the tree frogs. The latter may be heard as early as
February and the two species of frogs appear very soon after.
On the Western coast, Rana draytonii; and Hyla regilla are
breeding in January and February in California, and following
them closely Rana pretiosa and Hyla regilla are breeding in Wash-
ington. Members of the genus Scaphiopus have been known to
breed at various times from March to August, always during a
warm rain.
The length of the breeding season varies greatly. All of a
given species may resort to the water at about the same time
and remain there for a short period only, as in the case of the
Spadefoot Toad (Scaphiopus holbrookii) or less conspicuously of
the Wood Frog (Rana sylvatica}. On the other hand, they
may go to the ponds scatteringly and each individual linger there.
In the latter case the breeding season may extend over a period
of two or three months, as in the case of Bufo lentiginosus, of
Bufo americanus, and even more remarkably of Bufo fowleri.
lMacrobjella decora.
THE FROG BOOK
PLATE I
• - .-.
FIGS, i and 2.— The SPOTTED SALAMANDER (Amblystoma punctatiim Linn). Providence, R. I. [Enlarged.]
The spherical eggs enclosing the embryos are within an external mass of jelly. The full-grown larva has a tail fin and ex-
ternal gills adapting it to water life.
FIG. 3.— SPOTTED SALAMANDERS i year old. Black and yellow. These are typical representatives of the
Urodela which together with the Salientia, or frog-like forms, constitute the two classes of the North American
Batrachia.
THE EROG BOOK
PLATE II
In May, when birch trees are in their splendour of young leaves, frogs and toads announce spring from all the waterways.
Development
Investigation has yet to prove that any given North American
species has more than one true brood each year. The fertiliza-
tion of the egg is external and the grasp of the male is back of
the arms, except in the Discoglossidae and the Pelobatidae, where
it is inguinal, as among the Salamanders. When several species
are breeding in a given pond, they may divide the space and form
themselves into colonies. The same exclusiveness is true later
of the tadpoles also.
For details of the development of the frog's egg, see pp. 176 to
1 8 1 , and for those of the toad's egg, see pp. 67 to 7 1 . The Salientia
show their close relationship by the similarity in the development
of the eggs. The time element varies with the species and with
the temperature in the case of a given species. Some embryos
hatch in less time than others — in two or three days even (Bufo
americanus) instead of in as many weeks (Rana pipiens) — and
thus may be at an earlier stage of development at the time of
hatching. They may therefore either pass through a quiescent,
clinging stage after hatching (Figs. 35 and 248), or omit this
and become active at once. There may be differences in colour,
in the extent of the development of the external gills, and in other
details, but, on the whole, if we know the story of development
in one species, we know what to look for in other species also.
This applies equally to the metamorphosis of the tadpole.
(See American Toad, pp. 69 and 70, and Bullfrog, pp. 235 to 238.)
The length of life of the tadpole before its change into the frog
may vary from two or three weeks to as many years. Some of the
interesting points possible to observe during the metamorphosis
are the following: The arms and legs develop simultaneously,
but the arms are concealed under the opercular membrane. (Fig.
280.) The left arm appears first, because of the presence of the
breathing-pore orspiraculumontheleftside. (Figs. 284 and 285.)
The eyes are elevated, become free, and have movable lids per-
fected. The lachrymal canal shifts upward and backward tow-
ard the eye and enters the lower eyelid. (Fig. 287.) The horny
parts of the mouth are dropped and the mouth cavity increases
in size. The tail becomes smaller by absorption from within.
The tadpole takes on habits of rushing to the surface or of resting
wholly out of the water (Figs. 287 and 288), showing that the
lungs, which for some time before had been functional in company
with the gills, now take on all of the respiratory work (except
5
Introduction
that performed by the skin). Within a short time after the ap-
pearance of the arms, the skin of the opercular membrane has
grown to that of the arm and a distinct seam is visible at the
line of union. (Figs. 289 and 229.) This seam is sometimes visible
in the second year after the metamorphosis.
The metamorphosis may take place in a relatively short space
ot time, often being hastened by lack of food. Hunger causes
earlier degeneration and resorption of the edible portions of the
tail and opercular membrane, and hence hastens the metamor-
phosis. On the other hand, the change may be delayed by good
feeding and low temperature, and by any disturbance which
results in requiring the expenditure of energy on the part of the
tadpole. As the tail becomes smaller and no longer functional,
its colour darkens until it is nearly black. This is due to the
concentration of the pigment that was previously spread out,
giving colour to the tail and its fin.
One of the most interesting structures of the tadpole is the
system of the lateral line organs. These are sense organs of the
skin that appear to the naked eye as dots of lighter or darker
colour, but are really tiny papillae at the ends of tubules of the
skin. They are arranged in curving rows on the top of the head
and around the eyes. They also extend backward to the tail or
beyond, usually in three irregular rows on each side. (Fig 4)
Their arrangement differs somewhat in the different genera and
species and they are more prominent in some than in others. In
a given individual they may be more conspicuous at some times
than at others, depending on the colour of the tadpole at the time
the observation is made. Each papilla is in direct connection
with a fibre from the lateral branch of the vagus nerve, and the
system of organs is supposed to provide a special sense necessary
in some way to aquatic life. Organs of the lateral line are uni-
formly possessed by Fishes; the organs of the lateral line possessed
by the Salientia are known in the tadpole stage only, and dis-
appear at the time of the metamorphosis. (See p. 14.) There
has been much difference of opinion as to the exact function of
these organs, but they are now regarded as refined organs of
touch, making the creature sensitive to vibrations of the mass
of water. They have developed from the skin, which is sensitive
to waves and currents of water. It is thought that the internal
ears have developed from organs of the lateral line, and the ears
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Classification
are sensitive to the most delicate vibrations of the water pro-
ducing sound. The sense organs of the skin, the lateral line and
the ears, then, are closely related in origin and in function.
IV. The Families of the Salientia or Tailless Ealrachia
The Tailless Batrachia of North America, as far as known,
are represented by seven families, containing together twelve gen-
era and fifty-six species. In addition, there are a few forms that
rank as subspecies. All show slight modifications of one narrow
plan of structure, and are sometimes distinguished from one an-
other by close discrimination only. Their natural classification
rests on minute details of internal structure. It is based, for the
most part, first, on the ventral structure of the shoulder-girdle
(Fig. 5); and second, on the shapes of the sacral diapophyses,
those bones that form wing-like extensions of the sacral or ninth
Vertebra and connect directly with the ilia or hip-bones. (Fig. 6.)
Order SALIENTIA.
I. Superfamily Arcifera.
The two halves of the shoulder-girdle (coracoids and
precoracoids) overlap in front so that the chest is capable
of expansion. (Fig. 5.)
A. Sacral diapophyses dilated. (Fig. 6.)
1 . Terminal phalanges of skeleton not claw-shaped.
a. Vertebra opisthocoelous, ribs present, teeth on
upper jaw.
Family i. Discoglossida (Ascaphus, p. 51).
b. Vertebrae opisthocoelous, or proccelous, ribs absent,
teeth on upper jaw.
Family 2. Pelobatidce (Scaphiopus, etc., pp. 43 and 53).
c. Vertebrae proccelous, ribs absent, teeth absent.
Family 3 Bufonidce (Toads), pp. 44 and 63.
2. Terminal phalanges of skeleton claw-shaped and
supporting adhesive disks.
a. Vertebrae procoelous, ribs absent, teeth on upper
jaw. Family 4. Hylidce (Tree Frogs) , pp. 46 and 1 1 7.
B. Sacral diapophyses cylindrical. (Fig. 6.)
Vertebrae procoelous, ribs absent teeth on upper jaw.
(Very like the frogs, except for the arciferous shoulder-
girdle.)
Family 5. Cysiignatlidce (Lithodytes, etc., pp. 45 and 163).
7
Introduction
II. Superfamily Firmisternia.
The two halves of the shoulder-girdle meet in front and
unite (coracoids and epicoracoid cartilage), so that the
chest is not capable of expansion. (Fig. 5.)
A. Sacral diapophyses dilated.
Vertebras proccelous, ribs absent, teeth absent or pres-
ent. Family 6. Engystomahda (Engystoma pp. 48 and
1 66). B. Sacral diapophyses cylindrical.
Vertebrae precocious, ribs absent, teeth on upper jaw.
Family 7. Ranidce (Frogs), pp. 48 and 171.
Family I. Discoglossida
This is the most primitive family of the Salientia, resembling
the Salamanders in the possession of ribs and in other detailed
characteristics of the skeleton. The tongue is round and only
slightly free behind, so that it cannot be extended for the capture
of food. At the breeding season the clasp of the male is lumbar
or inguinal, as among the Salamanders and the Pelobatidas. The
tadpoles have the breathing-pore situated on the midline below,
instead of on the left side as in all other families of the Salientia.
Until 1897, when a new genus of the Family was found at
Humptulips, Washington, the Discoglossidas contained only four
genera, and were supposed to be unusually limited in distribution.
They were reported from Europe, southwestern Asia, northern
Africa, and the island of New Zealand only, never having been
found in the Western Hemisphere, or in tropical Africa, Asia, or
Australia. (Refer to p. 51.)
Family II. Pelobatidce
This family, related to the Discoglossidas below and the Bu-
fonidae above, also shows some primitive characteristics of struc-
ture, and the clasp at the breeding season is inguinal. The mem-
bers of the Family are strictly nocturnal, as is evidenced by the
vertical pupil of the eye. They are burrowing in habit. The
foot is unusually thick and leathery and is provided with a large
sharp-edged digging spur (inner sole tubercle).
The Family is well represented in North America and Mexico
and in the Eastern Hemisphere, with the exception of tropical
regions. Seven genera are known and about twenty species.
North America has four representatives of the one genus Scaphi-
opus. (Refer to p. 53.)
8
Classification
Family III. Bufonida
The Bufonidae includes batrachians differing greatly from
one another in appearance. They always have parotoids, and
the ear is fully developed. But they may be short and stout
or quite the opposite, rough and dry-skinned or smooth and slimy.
In habit of life they may be terrestrial, burrowing, aquatic, or
even arboreal.
The family includes eight genera, with many more than a
hundred species, but, curiously enough, one of the genera, Bufo,
includes all but fifteen of these species. The Bufonidae is the
most nearly cosmopolitan of all the families in its distribution;
Madagascar, Papuasia, and the small islands of the Pacific, are
the only regions not possessing representatives. The greatest
number of genera is found in Central America ; the greatest number
of species, mainly Bufo, of course, occur in Central and South
America. The genus Bufo is lacking in the Australian region.
Bufo is the only genus of the family found in North America,
but this genus has thirteen species and a few allied subspecies.
Texas has the greatest number of these species. (See p. 63.)
Family IV. Hylidce
This family embraces the arboreal Salientia, or Tree Frogs.
It is most nearly related to the Bufonidae, and is, next to the
Ranidae, the largest family of the Salientia.
The tree frogs are relatively small in size and are often green
in colour. The ends of the fingers and toes are provided with
adhesive disks, by means of which the creatures climb with great
skill. They have large resonating pouches, and voices that are
surprisingly loud when compared with the small size of the singers.
Their distribution is cosmopolitan, with the exception of
the African region. The rich forests of Central and South America
have the largest number of representatives of the family — some
one hundred thirty species; Australia has about thirty species
and North America fifteen. In the rest of the world, six species
only are represented. Of the North American species, ten
are members of the genus Hyla; the others belong to Acris, Cho-
rophilus, and Smilisca. (Refer to p. 1 17.)
Family V . Cyslighaihidce
The old family of the Cystignathidae is nearly as large as the
Hylidae. It is not well defined, but overlaps in its characteristics
9
Introduction
the Hylidae, the Pelobatidae, and the Ranidae. It resembles the
first in sometimes possessing adhesive disks on fingers and toes;
the second, in that the sacral diapophyses are in some species
dilated instead of cylindrical; the third, in nearly all ways, except
the fundamental one that it has a shoulder-girdle of the arciferous
instead of the firmisternal type.
The various members of the family show habits aquatic or
terrestrial, burrowing or arboreal, and have proportions and struc-
tures adapting them to these various existences. The largest
number of species occurs in Mexico and Central and South Amer-
ica, but Australia is also well provided with them (twenty spe-
cies). Outside of these regions, the Family is not known, except
for the few forms found in North America, due to the overlapping
of the northern and southern zoological realms. North Ameri-
can genera are Lithodytes of Florida and Texas and Syrrophus
of Texas. (Refer to p. 163.)
Family VI. Engystomatidce
With some exceptions, these "Narrow-mouthed Toads"
have, as the name implies, a narrow pointed head and a small
mouth in sharp contradistinction from the type among the Sali-
entia. .t These structural characteristics of the family are related
to the habit of feeding upon ants and minute insects only.
The body is usually very stout, making the small size of the head
all the more striking. The ear is usually invisible. Most mem-
bers of the family possess no teeth on the jaw. There are never
palatine teeth, but often there is a serrated ridge across the roof
of the mouth in front and a second one farther back. These
ridges may 'be a modification in structure due to ant-eating
habits.
The shoulder-girdle is always of the firmisternal type, but
it differs greatly among the various members of the family in its
details of structure. The pupil of the eye may be vertical, cir-
cular, or horizontal. The legs may be short or long; the toes
provided with disks or not. In fact, outside of the fundamental
distinguishing features (shoulder-girdle firmisternal, sacral dia-
pophyses dilated), there are few points of likeness among the
members of the family. Boulenger has divided it into three sub-
families, and the unlikenesses are evident also from the fact that
there are only about twice as many species as genera.
10
Phylogeny
The Engystomatidae are tropical in their distribution. The
only North American species found outside of southern Texas
is Engysioma carolinense. This is found in a belt across the con-
tinent from Florida to Texas, inclusive, and as far to the north as
Virginia (Cape Charles), southern Illinois, and Missouri. (Refer
to p. 1 66.)
Family Vll. Ranidce
The Family of the Ranidae is the most specialized of the
Salientia; it is also one of the most unified families in its structural
characteristics. The shoulder-girdle is not only always firmis-
ternal in type, but also usually agrees with the type for the fam-
ily in its details (such as the presence of the precoracoids and a
well-developed omosternum and sternum furnis'hed with a bony
style). The cranium also constantly shows the same character-
istics (such as the absence of a frontoparietal fontanelle).
The family contains a large number of genera, and it is very
widely distributed. Australia, New Zealand, and southern South
America are the only parts of the world not possessing represent-
atives of the true frogs. Some two hundred species (by far the
largest number) are found in the tropical portion of the Eastern
Hemisphere. North America has only one genus, Rana; there
are seventeen known species, and one form of the rank of a sub-
species (Rana c. latiremis). They are most numerous in the
eastern part of the continent, though several species are found
west of the Sierra Nevada Mountains. See p. 171.
V. Phylogeny
It is not until recent years that the Batrachians have been
recognized as a distinct Class, intermediate in position between
the Fishes and the Reptiles. This is partly because of the rela-
tively high specialization of some of the living batrachian species,
a specialization that removes them from the direct line of evolution
and makes necessary a large amount of comparative morphologi-
cal and embryological investigation before their true relationship
can be discovered. In France and Germany, in England and
lastly in America, this work has been going on since the time
of Linnaeus in the eighteenth century. Linnaeus classified Batra-
chians, some of the Fishes, and Reptiles together, calling them
Amphibia. Since then Batrachians have been classified with
ii
Introduction
the Fishes and again and again in various combinations with the
Reptiles. They were first recognized as a group distinct from
both Fishes and Reptiles in I804,1 and were then called Batrachia.
There is now no question but that the Batrachians, no mat-
ter how they differ in form, are closely related to one another
and are descendants of the Fishes. Neither is there any question
that in the past ages some primitive forms of Batrachians, now
extinct, formed the direct ancestors of the Reptiles. An under-
standing of their relation to other animal races has been facilitated
by the discovery of fossil remains of Batrachians and Reptiles.
Fossil Batrachia — the Stegocephali2 — have been found which
by the structure of the skeleton show evidences of descent from
either the Dipnoi or Crossoptergii (extinct Fishes). Fossil Rep-
tiles - - Proreptilia and Theromorpha 3 — have been discovered
which in their turn seem to produce a gradually traced line of
evolution from these extinct Stegocephali to higher Reptiles.
The Stegocephali are found in largest numbers in the Car-
boniferous strata of North America and Europe. They thus
must have flourished during the Coal Period in North America,
that early epoch in the history of the earth following the Age of
Fishes and preceding the Reptilian Age. At this time, the conti-
nent, which extended from what is now the Appalachian Moun-
tain region west to Kansas and Nebraska only, was in a semi-
emerged condition. The great areas of marsh were filled with
jungles and rank growths of fern and conifer, with an animal life
represented by many of the lower invertebrate forms (among
them some of the lower insects), and by the vertebrate classes
of the fishes, these early batrachians (the Stegocephali) and a
few of the early reptiles. But there were no flowering plants,
no moths, or butterflies, bees, or wasps; and the great silence was
unbroken by bird or mammal. That the Stegocephali did not
flourish much beyond this Coal Period is proved by the fact
that their remains are found in ever smaller numbers from the
lower Permian (at the close of the Carboniferous era) through
the Trias (of the Reptilian era), and that above this, their repre-
sentatives are almost wholly lacking.
l Brongniart, " Essai d'une Classification Naturelle des Reptiles."
2Stegocephali (Cope); Labyrinthodontia (Huxley). The latter represents the former in part
only.
3 The fossils which have been assigned here may prove to be Stegocephalian instead of
Reptilian.
12
Phylogeny
In North America to-day, the Carboniferous strata made in the
Coal Period are best represented in the region of the Alleghenies.
It is in this region, in the upper Coal Measures of Pennsylvania,
Ohio, and adjoining states that the fossils of the Stegocephali
are found. They have also come to light in the Coal Measures
of Nova Scotia.
These earliest four-footed, air-breathing vertebrates were
often of considerable size (several feet in length). This is proved
not only by their skeletons, but also by footprints left by them
on slabs of sandstone both in Europe and in America. Usually
they resembled the Salamanders in shape, sometimes possessing
very long tails. The body carried a partial armour of bony plates
or scales and the head was heavily armoured. The skeleton
is in a relatively generalized condition such as might have
developed into the relatively more specialized types found in the
lower Batrachians (Apoda and Urodela) and in some extinct Rep-
tiles. The presence of pentadactyle limbs of course proves the
Stegocephali higher than all Fishes, but the shoulder-girdle is prim-
itive, resembling that in the Dipnoian Fishes, and the pelvis
and cranium present features very different from those of the
typical Fishes, but in some respects like those in the Dipnoi and
Crossoptergii and some extinct Reptiles. That the Stegocephali
are not Reptiles is proved perhaps by the presence of two
occipital condyles, whereas Reptiles have but one; it is proved to
a certainty by the structure of the vertebrae. (They are never
gastrocentrous, as in Reptiles.)
The path of evolution from these extinct Stegocephali to
the Urodela and the specialized Salientia is obscure. It is not
known whether the intermediate ancestors were forms breathing
by mean of gills throughout their lives (Perennibranchiata) or
were already air-breathers. In fact, it is not even known whether
the Urodela and Salientia arose separately from the Stegocephali
or whether they had intermediate common ancestors. The oldest
form of the Salientia known is represented by fossils from the
Jurassic beds of the Rocky Mountains (representing the middle
period of the Age of Reptiles). So little is known of this form,
however, that it has little weight. The earliest reliable evidence
of anything approaching modern types is given by a small skele-
ton found in the Cretaceous of Belgium (the latest period of the
Reptilian Age, just previous to the Tertiary) ; this is thought to
13
Introduction
be a perennibranchiate Urodele (Hylaeobatrachus). Probably Ba-
trachia were abundant throughout the Reptilian Age (Mesozoic),
but were represented by delicate, marsh-living animals not suited
to fossilization. The modern types of the Salientia appear in
the Tertiary with about as many genera and species as now.
Not only do the Salientia show their development from the
Fishes through fossils, but their structure still tells the story of
their descent. In addition to this, some points of the proof are
shown in their development through a larval form adapted to
water life.
The adult structure which constitutes the main likeness is
the three-chambered heart with its valved conus arteriosus and
the symmetrical arrangement of arterial arches. Two of the
telling points in the development are the presence of lateral line
sense organs previous to the metamorphosis (p. 6), and the
existence of four or five gill arches in the larva. It is thought
that the gills of the tadpole are not phylogenetically related to
the gills of true Fishes, but that they are so related to the ex-
ternal gills possessed by some of the Dipnoi and Crossoptergii,
or that they have developed in response to the needs of the tad-
pole in its adaptation to a water environment. This is true
even of the so-called internal gills, which replace the first external
gills and are covered by the opercular membrane. They have
been called internal because they were under this opercular mem-
brane, not because they were homologous with the internal gills
of Fishes.
The lowest of the Salientia and the most nearly related to
the primitive Batrachians are the Discoglossidae (outside of the
Aglossa, which are not represented in North America). These
have not only the primitive characteristics of the skeleton (ver-
tebrae opisthocoelous, distinct short ribs, etc.), but they have other
structures also in primitive condition. Such is a tongue adherent
to the floor of the mouth, so that they must capture food with
the jaws, as do the Urodela. The Pelobatidae are perhaps inter-
mediate in position between the Discoglossidae and the Bufonidae
and lead also to the Cystignathidae. These last, in their turn,
point towards the Hylidae. The Ranidae are thought to be the
highest among the Salientia.
Thus, historically, Batrachians are more interesting than any
other vertebrate Class. They bridge the greatest gap in verte-
14
Hibernation
brate evolution: they made the change from water life to land
life at the time when the earth reached the condition in which
land existence was possible.
Their small numbers now — only one-eighth that of the
Fishes, one-fourth that of the Reptiles, and one-tenth that of
the Birds -- and the few fossils found would seem to prove that
they never became a dominant group. Not remaining perfectly
adapted for water life, as are the Fishes, never becoming in-
dependent of water and fully adapted to land life, as are the Rep-
tiles, they have been at a disadvantage as a race. They have
been limited in their distribution to moist situations near water,
and have been wiped out of existence in large numbers when con-
ditions changed, because they were not able to migrate over dry
regions until they again found a proper habitat. Also, during
those ages when the earth was occupied by Fishes, Batrachians,
and Reptiles only, the Batrachians could not but be unequal
to the situation, pitted against two devouring races, the Fishes
in the water and the Reptiles on land.
VI. Temperature and Hibernation
All Batrachians, like Fishes and Reptiles, are cold-blooded,
i.e. they have a variable body heat, depending on the tempera-
ture of the environment. In this they are distinguished from
Birds and Mammals, which have an unvarying body temperature.
Because of this variation of the body temperature with that
of the surroundings, Batrachians can endure extremes of heat
and cold, but are greatly influenced by them. With decreasing
temperature the processes of respiration and circulation gradually
slacken speed, and the animals become more and more lethargic
until they sleep. With rise of temperature to a limit varying
from 20° to 30° Centigrade in the different species, they gain in-
creased activity.
Members of the Salientia can endure an astonishing amount
of cold; even freezing in the water of a pond or in the mud at
its bottom will not of necessity cause death. The circulation
and all life processses may stop, but if the blood and protoplasm
of the heart do not fall much below freezing-point, the frozen
parts will recover. Since sleep is induced in specimens at vary-
ing temperatures below 10° C., it is easy to understand why Ba-
trachians are not found in the extreme north.
Introduction
In the autumn, when the frog or toad feels this slowness and
inactivity of the body functions, it creeps away into some pro-
tected place or burrows into the soil. (Refer to p. 33.) The
burrow is pushed to a greater or less depth, depending on whether
the place chosen is at the bottom of a pond, under logs or stones,
or in the open earth of gardens or fields — depending also on the
species and on the age and consequent size and strength of the
individual.
This hibernation or sleep induced by cold continues until
a return of high temperature. If by any cause climatic conditions
of the spot chosen should change, or if chance led the batra-
chian into a deep well, cave, or other cold situation so that a
sufficiently high temperature never returned, hibernation would
continue for years perhaps, until, still sleeping, the creatures
died from exhaustion of vital forces. Frogs that have been frozen
are always found in the hibernating position.
The Salientia can endure a greater degree of cold than of
heat. It is thought that in water death occurs at 40° C. Thus
tadpoles and water frogs are often killed in large numbers in
the shallow pools of Texas. Land frogs and toads hide away
in cooler situations under moss and stones in shaded regions and
pass through a period of aestivation till lower temperature re-
turns. The tree frogs can endure much higher temperature than
can dry-skinned toads or water frogs. It is said that they can
sit in the sun at a temperature of 60° C. (120° F.). This is pos-
sible because of the moisture secreted by their skins. The fact
is that they do not actually experience this high temperature
because evaporation keeps the surface cooled to a much lower
point.
VII. Tie Poisonous Character of Frogs and Toads
When annoyed or when taken roughly in the hand, mem-
bers of the Salientia squirt out from the urinary bladder a trans-
parent fluid wholly harmless in character and usually odorless.
When handled very roughly by an enemy, a secretion is given
out in minute quantities from glands in the skin. This is not
harmless if taken into the system of an animal; it is a poison
varying in amount and intensity with the species.
The skin of the Salientia is thickly set with glands. These
may be so small that they are invisible to the naked eye, the
16
Poison
skin appearing perfectly smooth. On the other hand, they may
be larger, and if large, are either few and scattered or many and
aggregated — the latter condition being illustrated by the warts
and parotoids of the toads and by the lateral folds of some of
the frogs.
It is thought that these glands are of two kinds, slime-glands
and poison-secreting glands. The slime-glands have for their
chief function assistance in the process of respiration by the skin.
But it is thought by some that their secretion serves a secondary
purpose of protection; that it is an alkaloid and acts as a nar-
cotic. The larger poison-secreting glands are sometimes so few
and scattered as to be invisible to the naked eye, but often are
gathered together in conspicuous elevations. In these aggrega-
tions of glands the openings are sometimes plainly visible to the
naked eye. (Parotoid glands, Figs. 48 and 89.) The secretion is
milky in appearance and acid in character and is .thought to act
as a convulsive.1
The value of the secretion lies in its protection of the Batra-
chian from enemies who would otherwise devour it. This poison
is not aseptic, as is the case in poisonous snakes, but acts upon
the heart and central nervous system. That of the European
toad Bujo vulgaris has been compared to Digitalis and Erythroph-
lasum.2 Numerous experiments have proved that toad poison
injected into the system will kill any vertebrate, the dose being
proportionate to the size of the animal.
If a young dog takes a toad into its mouth, it will
never repeat the act, and perhaps suffers much discomfort for
twenty-four hours or more because of this first offence. Snakes
eat toads without any apparent discomfort. Skunks are fond
of toads as an article of food, but before they eat them they
roll them roughly under their paws on grass or other low vege-
tation until the poison has been sent out from the glands and
rubbed off on the grass. Rana cesopus, the gopher frog of Florida,
eats toads, but ejects the poison from the mouth almost imme-
diately after swallowing the toad. If the frog is in water, this
poison floats at the surface in conspicuous white foamy masses.
Frogs have less poison in the skin than toads have, and serve
as food for all sorts of animals, especially for birds. Herons feed
iPhysalix, 1890.
2Boulenger, iSgy.
17
Introduction
largely on bullfrogs ; leopard frogs have been found in the stomach
of a loon ; l bronzed grackles have been observed eating wood
frogs,2 and so on.
The poison secreted in the skin of theSalientia concerns only
the enemies who feed upon them; it does not affect man. The
secretion, even if rubbed on the hands, cannot cause the forma-
tion of warts; however, it will produce an irritation and smarting
if transferred from the hands into the mouth or eyes. It is said
that German violinists purposely handle toads before playing,
and that the secretion prevents the hands from perspiring greatly.3
VIII. Regeneration of Lost Parts in tie Salientia
In the Urodela the power to regenerate lost parts is very
great. Not only the gills and the tail of a salamander, but the
limbs also, will be reproduced perfectly if bitten off by some hungry
beetle or fish, or torn off by one of its own kin.
This power of regeneration extends also to the more special-
ized group, the Salientia, but the reproduction of the lost part
is the more perfect, the younger the specimen. The tadpole's
tail may be bitten off or injured again and again, and each time
it will grow to its previous size.4 This is true even at the
time when the period for the resorption of the tail has almost
been reached.
If the hind limb of a metamorphosing tadpole be injured,
even amputated, above the knee, before the completion of the
metamorphosis, it will be regenerated completely. After the
frog form is attained, the power of regeneration is largely lost,
although the injured limb will always show some tendency
toward replacing the lost portion.
IX. Voice among ihe North American Salientia
All members of the North American Salientia can produce
sound. This sound is caused by air passing over vocal cords
in the larynx of the throat, and so it constitutes a true voice.
The loud croaking given during the breeding season is produced
i Hills (T. M.), Zoological Society Bulletin, N. Y. Zool. Soc., April, 1904.
2Miller (W. De W.), Plainfield, N. J., Bird Lore.
3 Boulenger.
« For the relation of this regeneration to the notochord, see Bryn Mawr College Monographs,
1902. Morgan (T. H.) and Davis (S. E.).
18
Voice
usually by the males only of a given species. The air enters at
the nostrils (the mouth is kept closed) and passes back and forth
from mouth to lungs over the vocal cords. The sounds can be
produced under water, and often are in the case of our common
bullfrogs.
The Salientia possess internal vocal sacs in the region of the
throat or on each side at the shoulder. These, when inflated, may
push out and stretch the loose outer skin of the body, and thus
show as external vocal pouches. The vocal sacs are filled with
air, through openings from the mouth, and act as resonators, in-
creasing the volume of sound. Single external vocal pouches at
the throat are possessed by Engystoma and Hypopachus, by
Bufo fowlen, Bufo -pundatus, Bufo lentiginosus, Bujo americanus,
Bufo I. woodbousei, and by all members of the Hylidae. (Fig. 7.)
Fig. 7. The Common Tree Frog — (i) in resting position
with lungs inflated and body large, and (2) singing, the air
from the lungs forced into the throat vocal pouch.
Vocal bladders inflated from the middle of the base of the throat
are to be found in Bufo cognatus, Bufo compadilis, and Bujo
quercicus.1 (Fig. 8.) Vocal pouches visible at the shoulder are
1 Living male specimens of Bujo hemiophrys and Bujo debilis have not been examined.
19
Introduction
Fig. 8. Bufo compactilis with vocal bladder extended
from base of throat.
conspicuous in
Rana pipiens and
Rana sphenocepka-
la, Rana areolata
and Rana cesopus
and in Rana virga-
tipes and Rana
grylio. (Fig. 9.)
Other North
American mem-
bers of the Sali-
entia, as far as examined, have internal vocal sacs which show
their positions during the croaking but do not inflate so greatly
as to have the skin over them become thinned.
Each species has its typical call, or " song," with definite
pitch and quality of tone.
The calls are exceedingly
simple, seldom involving
anything like rhythm or
melody. However, sev-
eral of the calls contain
notes of different pitch
usually sliding into one
another (Bufo jowleri,
Rana catesbiana), and
all are given with an em-
phasis and expression pe-
culiar to the given spe-
cies, so that we cannot
say that the calls lack
character. In a few
cases they are decidedly
musical and pleasing to
the ear.
The typical call of
the Salientia Consists Of FiS- 9- Leopard frog, drawn to show vocal
, T-, pouches extended at the shoulders.
a single note. 1 he note
may be short and repeated in very rapid succession, as that of
Acris gryllus', or longer and given in less rapid succession, as is
that of Hyla pickeringii; or decidedly prolonged and given at
20
Voice
still greater intervals, as in the case of Bufo americanus. This
single note may be of any pitch whatever, high or low; and frogs
of the same species may give calls of different pitch; in fact, there
seem to be two or three prevailing tones in the case of some spe-
cies. This is decidedly true of Bufo fowleri and Hyla pickeringii.
Again, the note may be smooth and unbroken (Hyla pickeringii),
vibrated so rapidly that it reminds one of the buzzing calls of
some Orthopterous insects (Engystoma carolinense) , or trilled
in a pronounced fashion (Hyla versicolor). The quality may
vary as greatly as the pitch, being sweet and musical (Bufo amer-
icanus), sonorous and musical (Rana catesbiana), harsh and
squawking (Bufo compactilis), like the rattling of pebbles (Acris
gryllus), and so on. The character and expression in many
cases is easily recognizable: for instance, the song of Bufo ameri-
canus is reposeful, almost serene; that of Hyla versicolor sug-
gests comfort, just as the purring of a cat does; Bufo Fowleri
voices woe and desolation with every note; and Bufo quercicus
would seem to be expressing most active distress in its tones
like those of a lost chicken.
Enough to say that these calls of the Salientia are easily
recognized after being once heard and identified, and although
they are less complex and musical than those of the birds,
nevertheless we get much pleasure from the recognition of these
primitive songs of a primitive race. They not only act as tol-
erably accurate barometers, thermometers, and calendars, but
in our travels through new parts of the country announce to us
something concerning the fauna of the place without investi-
gation on our part.
During spring and early summer we are likely to hear not
the voice of a single performer of a given species, but the com-
plex sounds produced by a chorus of performers. The result
of the many voices may be a harsh and discordant medley or
an effect of harmony, depending on the species, the number
singing and the vigor and rapidity with which they are produ-
cing the sounds. Rana catesbiana and a few others do not
sing in chorus.
The females, as a rule, produce less loud and emphatic calls
than those given by the males. They never show external vocal
pouches. In some cases they seem to be voiceless. However,
many that were thought voiceless have, during later investiga-
21
Introduction
tion, been heard to produce sounds. Further investigation will
probably prove all to have the power of producing weak sounds
of some sort. Many frogs and toads, both male and female,
give a high-pitched cry when greatly annoyed, and some of the
frogs open the mouth and produce a scream so loud and so much
like the human voice that it is startling in effect. The female
bullfrogs (Rana catesbiana) of Wisconsin can give the low-pitched
"jug-o-rum" call with a vigor almost equal to that of the male,
also swelling the internal vocal sacs to a size almost equal to
those of the male.
X. Colour and Colour Change
Colour in the Salientia is largely due to pigment in the skin.
This pigment may be black, red, yellow, or metallic. The black
pigment is granular and is enclosed within cells (chromatophores)
which have the power of changing shape. With a low power of
the microscope, these dark, branched cells can easily be seen in
the thin web of a frog's foot or in the fin of a tadpole's tail. There
is usually a layer
of black pigment
cells just below
the epidermis,
which, itself, is
white and trans-
parent. These
pigment cells
may contract or
expand, radiat-
dfc % ingmanybranch-
A ^| es. If they con-
tract and retreat,
the surface of
the frog is left
9 light in colour
Fig. 10. When the pigment cells retreat and contract, ^ °'
the resulting color of the skin is light. expand, St retch-
ing out black an-
astomosing branches toward the transparent epidermis, the skin
appears dark (Fig. 1 1). Each cell is connected by means of a
slender nerve fibre with the sympathetic nervous system, which
22
»
Colour Change
in turn is connected with the central nervous system of the
animal. Therefore the cells can act in harmony and as the result
of a common stimulus. This stimulus may be brought to the cells
by reflex action from outside influences (such as light and heat)
acting directly on the skin, or by outside influences (such as the
colour of the surroundings) acting through the eye.1 Or, on the
other hand, the stimulus may be sent from within the animal by
reflex action, and may have its origin in the character of the
food or some item of the physiological condition of the creature.
Fig. ii. When the pigment cells send out interlacing branches
the resulting color is dark. After Lister.
It is easily proved that certain definite stimuli bring about
definite results. Bright light or heat causes the cells to contract
and the skin to become lighter in colour. Darkness or cold causes
expansion of the cells and resulting dark colour of the skin. Thus
hibernating frogs are dark-coloured; the same frogs sitting in
bright light are so light-coloured that they would seem a different
species to the casual observer. Absence or presence of moisture,
other conditions being equal, seems also to play a part in causing
the pigment cells to contract or expand. Toads kept in a dry
1 Blind specimens change colour much less rapidly than do those that are normal.
23
Introduction
place or found along a dusty road are light in colour, while those
kept or found in moist surroundings will prove to have the pig-
ment cells spread so that the skin is dark-coloured. Activity
on the part of the toad or frog has a marked tendency to pro-
duce a change to lighter colours; this is true even when there
are counteracting influences, such as darkness.
The change from light to dark and vice versa may take place
in as short a period of time as ten minutes (Hyla regilla, Hyla
squirella, etc). Again, the time necessary is habitually a half-hour
or more, as is the case with Hyla versicolor and Hyla gratiosa.
The rapidity varies with the species; but this further fact is al-
ways true, that in all species colour changes are likely to take
place more rapidly during the season of greatest activity (the
breeding season) and at a time when the creatures are abundantly
fed. During great scarcity of food, when the vitality is reduced,
the frog assumes a light colour, and retains such even under
strong counteracting influences.
Notwithstanding all these facts, there must be much not yet
understood regarding the change from light to dark and the re-
verse, since there are so many contradictions of these facts that
come under observation. Almost any given Hyla (gratiosa, versi-
color, cinerea, squirella, regilla) may take on some given colour,
usually a medium shade, and retain it for months without any
change during bright days and dull, when warm or cold, wet or
dry. This is true, also, of various species of Rana, perhaps of
all ; they seem to have a natural individual tendency toward a given
colour or shade and retain it in spite of changing conditions and
in company with other individuals of the same species which con-
stantly respond to these changes.
Again, frogs and tree frogs sometimes surprise one by be-
coming their lightest when kept in complete darkness and when
all conditions would seem to point towards their taking on their
dark dress. This is noticeably true of Hyla pickeringii and Hyla
cinerea. Again, some species of tree frogs, Hyla squirella in par-
ticular, will change back and forth again and again very rapidly
for hours at a time when the conditions remain the same. Thus
the process of change would seem not to be a wholly automatic
one nor the result entirely of reflex action. There are probably
internal factors to be taken into account, factors that have to
Colour Change
do not only with the physiological condition, but also concern the
primitive sensations and emotions of the frog. Some scientists
go as far as to say that changes of colour in Batrachia "can be
inhibited by the will and can be produced at will."
A frog that possesses a layer of black pigment cells under
the epidermis will, as indicated, change from light to dark, but
if there are no other pigments or other structures, the shades
passed through will be dull browns and greys. If yellow pigment
is possessed also, the changes will be from black through bright
browns to light yellowish shades. Green colour is not produced
directly by a pigment, but as the result of black and yellow pig-
ments and a structure, namely, the so-called interference layer.
This is a single layer of polygonal cells between the epidermis
and the black pigment layer. These cells contain minute yellow
particles, which crowd to the sides of the cells next the epidermis.
If these cells were empty, the result would be simply that the
black pigment layer would be farther from the surface and
would be seen through the interference layer. This would make
the colour appear blue instead of black, giving the ordinary
colour phenomenon of dense media, as seen in the colour of
the sky (i. e. all the light waves of great wave lengths are
absorbed and only those of short lengths are reflected). When
the interference cells contain yellow, the blue is seen through the
yellow and the resultant colour is green.
The green colour thus produced may be more blue or more
yellow, and may change to brown when the black pigment cells
expand greatly and press close about the cells of the interference
layer, thus diminishing the density. A fragment of the outer
skin of a green tree frog examined from underneath, of course
appears black, because we are looking directly at the black pig-
ment layer. The same piece looked at from above and against
the light appears brown, but examined from above with light
from above, it appears green and shows the polygonal cells of
the interference layer.
Therefore frogs that have the interference layer and black
and yellow pigments appear green or brown and can change from
one to the other with great rapidity. Sometimes to these pig-
ments and the interference layer are added pigments of other
colours, red, white, and metallic, or iridescent. Consideration
Introduction
of all these facts gives us some understanding of the astonishing
changes and combinations of colours seen in some of the North
American tree frogs, such as Hyla regilla.
As a rule, the colouration of the Tailless Batrachia is seldom
plain green or brown but is more or less spotted, mottled, or
striped, so that the animal blends with the detail of its background
and is more or less invisible. There are no Salientia in North
America that, like some of the black and yellow salamanders,
present sharp contrast of striking colours, and so warn their neigh-
bours of their poisonous character.
Broadly speaking, the lower Families have less complex pig-
mentation and skin structure than the higher forms, so that
their colours are likely to be greys, browns, and olives, with some
admixture of red and yellow. This is true of the Discoglossidae,
Pelobatidae, and Bufonidae. The most complex colouration is
possessed by the Hylidae and Ranidae. With exceptions, they
have the interference layer well developed, and so are brown or
green, changing from one to the other and through many shades
of each, besides having^additional effects produced by red, white,
and metallic pigments. Of the Ranidae, Rana palustns, sylvatica,
and virgatipes represent some of the species that, as far as ob-
served, are never green ; catesbiana, grylio, clamiians, and pipiens
are among those that change rapidly from green to brown.
The colours of the upper parts of the frog or toad make it
harmonize with its surroundings. Many Hylidae and Ranidae
have bright colours on portions of the body concealed during
rest, but displayed in leaping and swimming: witness the orange
yellow of Hyla versicolor, Hyla andersonii, and Rana palusiris,
and the bright red of Rana draytonii, as well as of Rana pretiosa
and Rana aurora of the Pacific Slope. These brilliant colours are
called flash colours.1 They may act as recognition marks for
others of the same species, or may serve to startle the enemy and
warn of the more or less poisonous character of the possessor.
The colour patterns of the Salientia are interesting when
we consider their origin in past ages. They have come into ex-
istence slowly, through the influence of light, and probably as a
direct result of the alternating spots and bars of sunshine and
shadow cast on the creatures by the sun shining through the
foliage of their environment. The pigment was gradually mar-
1 Hans Gadow, Cambridge, England.
26
Animal Behaviour
shalled into definite arrangement, and those frogs in which the
arrangement was such as to be helpful in hiding them in their
environment were missed by enemies, while others were destroyed.
The protective arrangements were inherited and again emphasized
through'generation after generation until we have in the Salientia
of to-day animals wellnigh invisible in their haunts. When we
do see them against their background of water and foliage, it is
wonderful how greatly the elongated spots and horizontal bands
of light and dark that make up the pattern on the back and that
cross the folded legs resemble the alternating sunshine and
shadow made by the sun shining between plant stems and grass
blades. The light-edged rounded spots of Hyla gratiosa and
Rana pipiens are marvellously like the shining sun-spots that
dance on the ground when sunlight is streaming through dense
foliage.
One of the most complicated conditions exists in the cases
where a given pattern is vividly displayed when the frog wears
a dress of some medium shade and is wholly obscured in the
light and dark phases of colouration. This is true of the colour
pattern of Acris gryllus, Smilisca baudinii, Hyla gratiosa, Hyla
versicolor, and others among the Hylidae, and of Rana catesbiana,
Rana grylio, Rana onca, and perhaps others among the Ranidas.
The origin of the colour of Salientia is still a problem. It is
largely a chemical problem, closely connected with the food of
the species and with the conditions of the chosen environment.
The pigments are thought to be mainly excretory in origin, waste
products deposited in the skin — perhaps through the influence
of light and heat — instead of disposed of in the ordinary fashion.
The white pigment is thought to be guanin, related to uric acid,
and the metallic pigments are named from their composition
"guanin cells" or " iridocytes."
XI. Animal Behaviour
" How intelligent is the creature?" is a question of interest
in the study of any animal. How many of its actions are the
result of automatic response to the various stimuli of the environ-
ment? How many can be explained wholly as instincts, that is,
racial habits inherited through a long line of ancestry and per-
formed alike by each and every member of the race? How many
actions denote intelligence higher than this?
27
Introduction
Watch a tree frog leap, catch a swaying branch with pre-
cision of aim, and balance itself perfectly on the frail support.
See the toad that has jumped to the top of the aquarium bal-
ance itself for a few minutes on the edge of the thin glass while
it makes an examination of the surroundings before proceeding.
Watch a frog that is sitting on some support adjust itself as you
tip the support now in one direction and now in another. These
actions look as wonderful as the feats of a rope-walker. They
are, however, automatic actions, and could be done by a frog
whose brain had been removed. The frog has a nervous sys-
tem that makes most delicately co-ordinated muscular response
through an elaborate system of reflex actions.
Frogs and toads are sensitive to various forces in their en-
vironment and give response according as they are acted upon
by these forces. For instance, the earth's gravity affects the
tree frog so that it is not at ease unless its head is uppermost.
Watch the frog turn again and again in desperate effort to keep
its head uppermost when its support is alternately held upright
and reversed in position.
On a warm day the frogs are in full view among the late
vegetation of the pond. The next day, after a drop in temper-
ature, not a frog can be found. Frogs in captivity remain out
of the water or sit with head and shoulders protruding until the
air becomes colder than the water. At this time they disappear
and lie with flattened bodies and lowered heads at the bottom
of the aquarium until a return of higher temperature. Thus
frogs give automatic response to temperature'stimuli.
The frog's method of eating is attended with much nervous
alertness, and sometimes with unsatisfactory results to the frog.
The food consists, in general, of living worms and insects, which
are seized and swallowed alive. The frog uses his hands to help
put the food into his mouth. The mouth has the sense of touch
highly developed, but the sense of taste is present in only small
degree. In all cases, movement of a small living object gives
the visual stimulus, and, psychologically speaking, brings to the
frog the suggestion of something to eat. Long experience of the
race has taught that only immediate and swift motor response
will result in capture of the food — the miller or grasshopper
may take wing, the slug disappear under a board, or the cater-
pillar roll into a ball and " play dead." Usually, the result of
28
Animal Behaviour
the immediate seizure of the moving object is satisfactory, since
almost all small insects and worms are part of a toad's or frog's
menu. But sometimes lack of examination of the object brings
dire results. Such is the case when a large stag beetle is
swallowed. Its huge pinching mandibles produce terrible effect
at once in the frog's stomach. Fortunately, the frog has a wide,
short oesophagus, so -that any disagreeable object can be disgorged
immediately.
This lack of examination of food has made possible various
stories about the toad: that is, that the American toad will seize
and swallow shot rolled toward him until he is heavy with it,
and that the Southern toad will again and again swallow the
burning ends of matches, mistaking them for fireflies. It also
explains an incident related in an old " American Naturalist."
A toad was seen to pick up an elm twig that had just fallen from
the tree above him, and the observer amusingly interprets that
the toad used the hands to play with the twig as though playing
upon a flute before finally dropping it.
However, although frogs and toads do, as a rule, seize moving
objects without examination and will try to eat even one's finger
or pencil, nevertheless there are many exceptions. Especially
in the case of the toads is a more intelligent method often pur-
sued. The moving object, if it is at all large or formidable, may
be stalked some distance and examined closely. In fact, the toad
may discriminate the forward-moving end and make.'special effort
to take the creature head first. If grass or earth are taken with
the food, the mouth distinguishes these through the sense of
touch, and the toad removes them, or tries to, using the hands
awkwardly for the purpose.
Also after swallowing a stag beetle or a very large unman-
ageable earthworm, the toad learns by his experience, and
cannot be tempted again by the same or similar objects. The
permanency of the lesson has not been tested. Experiments with
labyrinth tests have proved that the green frog can profit by
experience.1 The learning is very slow indeed, but after fifty to
one hundred experiences, a habit is perfected, and when tested
after the lapse of a month, still persists.
The frog's sense of sight is fundamental not only in the cap-
1 The Instincts, Habits, and Reactions of the Frog. Robert M. Yerkes. Harvard Psycholo-
gical Studies, Vol. I.
29
Introduction
ture of food. It is the sense on which almost total dependence is
placed for protection.
We are walking along the grassy margin of a lake. In a
small cove ahead, screened by shrubbery, a green frog gives a
vigorous croak. A second frog, a third, then many others, join
till there is a harsh medley of sounds. This continues for some
time; suddenly one loud voice stops, and instantaneously all are
hushed. Why? We were trying to see through the shrubbery,
and although perfectly silent, set a long flexible branch swayinjg,
which the frog evidently saw. Shall we say, as do myth and
story, that frog orchestras have leaders who intentionally signal
the others when to begin, are on the watch, and again give an
intentional signal on the approach of danger? Not at all.
Human interpretations will not serve for the frog world. The
following is the explanation.
Frogs are extremely alert in sight and hearing, especially
in sight. There was no movement anywhere in the horizon of
the pond, and one frog gave expression to the physical joy of
existence. This croaking was evidence to all the other frogs that
there was no danger present; their eyes gave the same proof of
safety that the first frog had gained, and one by one they joined
in the chorus. The bushes moved. One frog saw the motion
(not necessarily the frog that croaked first), was frightened, and
responded with instant silence. Perhaps others saw also; if
not, the sudden hushing of the one voice implied danger, and
every frog obeyed an impulse of fear and became silent. That is
all. Except that we have reasoned it out, while the frogs felt
and acted only.
Frogs see small objects best at a distance of three or four
feet. They will very often let a fly or worm crawl immediately
under their " noses " while they are staring with eager eyes far
ahead. Toads are] less far-sighted than frogs. However, frogs
may see an approaching enemy — a person, a bear, or a large
bird — ten or more feet away, that is they may give a motor
response when the enemy is at that distance.
There is the familiar " splash " ahead. One frog has seen
us. A second " splash," and a third, long before we can approach
near enough to see the frog blending as it does with the colours
of the bank. These second frogs and others ahead have the ad-
vantage in escape over the first, for they were put on the alert
30
Animal Behaviour
by the ominous meaning of the splash of the first. The sudden
splash made by a frog leaping into water is associated with danger,
since a frog is not likely to leap into the water unless it is startled
— it walks or jumps short distances to the edge of the water,
slips lightly into it, and swims. This splash, then, puts a frog
into a waiting state of unusual keenness of sight and alertness
of muscle. The frog may lift the head or take on a more atten-
tive pose, but usually the only external evidence of this alert state
is a changed rate of breathing. The throat movements are more
rapid, except in cases where the attention demanded, or the fear
induced, is relatively intense; in such a case, the breathing move-
ments may cease altogether for several seconds at a time.
It is not only the result of out-of-door observation, but it
has been proved by experiment that a frog does not give a mo-
tor response to sound alone (an illustration of a true inhibition
phenomenon), but that a sound stimulus intensifies the effect
of an accompanying visual or other stimulus. This explains not
only the instances given, but many others. It means, for instance,
that if the frog hears an insect before seeing it, he is put on the
alert, so that when he sees it his dash for it is more vigorous and
effective than it would have been with the visual stimulus alone.
The gopher frog of Florida, sitting at the mouth of its burrow,
hears a crunching on the sand or a crackling of twigs, and be-
cause of the warning of his ears is ready to beat a more vigorous
retreat when the enemy appears than he otherwise could. It
is unfortunate for the frog that the approach of the snake is so
soundless, and that the heron hunting at the pond is so often
statuesque and silent.
Frogs can hear sounds made in air, whether the frog's ear
is in air or under water. It is thought that the hearing is keenest
when the ear-drum is half in air and half in water. Frogs can
hear sounds of both high and low pitch. The green frog is said
to hear sounds varying in pitch from 50 to 10,000 vibrations
per second. In captivity, frogs prove constantly that they hear
sounds of all sorts. They often respond with croaking when the
sound stimulus is non-startling in character, whether that stim-
ulus be the croaking of another frog, the sound of running wa-
ter, or of human voices. It is probable that one of the most
ominous sounds in the ears of a frog is the pain-scream of one
of its own species. This is a high-pitched sound produced with
31
Introduction
the mouth widely opened. It is given only when the frog is
injured by an enemy or is in a state of great fear. The cry ex-
presses distress in large measure, and must imply to the listen-
ing frogs the presence of great danger.
The frog's ear has the functions of balance and orientation
as well as the sense of hearing.1 Sometimes in spring, after the
breeding season, a frog is found that has the ear badly injured.
Such a frog keeps the head lowered on the wounded side. It
cannot progress directly, but moves in a circle instead. The auto-
matic action of the frog's ear in the work of orientation is inter-
estingly seen when we move a frog in its aquarium or moss gar-
den from one part of the room to another; or when we walk
from one place in the house to another with a toad or frog sitting
on some support which is carried in the hand. At each corner,
even at the slightest change in course, the frog turns its head to
adjust itself to the new direction.
Sight and hearing are correlated senses, serving in the cap-
ture of food and the escape of enemies. The sense of sight and
the temperature sense are correlated in receiving stimuli which
result in various protective actions. In normal temperature,
frogs are attracted by light and move towards it (positively pho-
totactic). That a frog jumps into the water when frightened, in-
stead of landwards, probably illustrates the fact that a frog moves
toward the stronger light or more brightly illuminated surface.
Frogs in captivity constantly illustrate this relation to light.
In trying to escape from an opaque pail, they leap upwards; in
a glass aquarium they struggle to get directly through the glass
(even when the glass is covered with'white paper so that they
cannot see through it). A tree frog will try for hours to get out
at the upper end of a glass beaker turned upside down; darken
the upper part and the frog will go to the source of light below
and find the opening. A frog moves not only towards diffused
light but towards direct sunlight as well. However, it does not
remain in the sunlight, but takes a station near it, in diffused light
or shadow.
Frogs do not distinguish between a lighted space and a white
solid. They will turn towards a white card or paper and try
1The static and acoustic functions lie in the labyrinth organs (connected with the tympanum by
means of the columella), since there is no organ of Corti, as in mammals. It is thought that the
papilla basilaris (the nerve end organ from which originates the organ of Corti in mammals) is the
iv*r»of f*r\Tie*fmt*fl \n tlif ar-midir- ( unr-t Jr\n
most concerned in the acoustic function.
32
Animal Behaviour
to jump through it, and they may struggle at the impossible
task of working their way into the solid white surface made by
the leaf edges of a closed book.
That frogs are attracted by light and have definite orienta-
tion in regard to it sometimes produces interesting results when
frogs are in captivity, where the light comes strongly from one
or two directions only. The same response to the same stim-
ulus may place six or eight pickerel frogs in a row, each in resting
position with toes tucked under and head resting meekly on the
body of the frog in front of him; or a half-dozen green frogs
may make burrows in the moss side by side in a row and sit in
the burrows all facing the same way — six pairs of bright eyes
alert and contented.
In increased temperatures the positive response to light is
still greater up to a temperature of 30° C. Above this, the frogs
move away from the light instead of toward it. In decreased
temperatures, the response is less until at 10° C. frogs move away
from the light (negatively phototactic). This is true whether the
frogs are in air or water. Experiments l which have proved this
are interesting because of the explanation they give of the aesti-
vation habits of the Salientia in the high summer temperatures
of Texas and Mexico and the hibernation habits during the win-
ters at the north. Green frogs kept in a moss vivarium in win-
ter remain out on the moss in normal temperatures, but disap-
pear under the moss at once if the temperature of the room drops
much below normal, or if a window is opened and the cold wind
is allowed to blow over them.
Many North American frogs and toads show protective in-
stincts or racial habits, the immediate cause of which seems to
be unusually strong stimuli acting on the nervous system. When
a toad, frog, or tree frog is disturbed suddenly, it may fill the
lungs with air until they puff out at the sides, making the crea-
ture as broad as long. At the same time, the head is lowered
to the ground and the frog certainly looks on the defensive. It
seems reasonable that it would prove well-nigh invulnerable to
the attacks of an enemy like the snake that expected to swallow
it whole and head first.
A toad very often flattens and spreads the body and remains
motionless on the ground when startled by the approach of an
1 The Response of the Frog to Light. E Torelle. American Journal of Physiology, vol. 9.
33
Introduction
enemy. This makes it almost invisible, because of the likeness
of its skin in colour and texture to the soil. Many of the Salientia
play dead in response to an unexpected tactual stimulus. The
common toad will often hold the legs tight against the body and
inhibit all movement — even the breathing vibrations of the
throat — when seized by a dog or other enemy. The leopard
frog may stretch the legs backwards stiff and straight, fold the
arms on the breast, and inhibit the breathing movements. It
certainly looks like a dead frog as it lies motionless in one's hand
for fully a minute; suddenly with a lightning movement it is
gone before the hand can be closed over it. The cricket frog
plays dead in water. Taking a position with arms and legs rigid
and throat collapsed, it floats about helplessly like any stick or
leaf.
A very different protective instinct is possessed by some
members of the group. For instance, the gopher frog of Florida
has a ludicrous method of spasmodic instead of continuous ac-
tivity. When trying to escape an enemy, it remains motionless
for some seconds, after which it moves a short distance with
indescribable swiftness and stealth, and then appears statuesque
again in a new spot. This is repeated several times till the frog
is two or more feet from the enemy, when a few successive pro-
digious leaps take him far out of reach. The tree frog Hyla evii-
tata, when startled, may leap to a twig and take a position be-
hind it. Here, hugging the twig closely, it will keep out of the
range of vision of the enemy by moving alternately back and
forth, to the right when the enemy moves to the left, and vice
versa. This instinct is probably possessed by many of the tree
frogs, though observed in this one only.
On the whole, it would seem that frogs and toads possess
but a low order of intelligence. There are but few glimmerings
of anything above automatic response to stimuli, behaviour
resulting from reflex actions and hereditary instincts. They
certainly form crude ideas of food and enemies. They evidently
associate certain stimuli with crude ideas, such as the coming
of an enemy or something to eat. It has been proved by ex-
periment that they may associate two kinds of stimuli: after
having received an electric shock on touching given wires, they
afterwards leap as soon as they touch the wires and before the
electric current is turned on.
34
Distribution
They feel discomfort from hunger, cold, and lack of water;
physical comfort from food, warmth, and moisture. They feel
physical joy and express it in song. They certainly possess the
one emotion, fear. Frogs are more excited^byjfear than^are toads.
A frog when frightened will dash into anything or from any height.
A toad will proceed to the edge of a table or window, and stop
to examine the surroundings before jumping.
Frogs and toads can be tamed somewhat. They will come
out of their burrows for food at a given time and will take it from
the fingers. They will get used to the movements of people and
to all kinds of sounds. On the other hand, they walk over one
another, and in fact pay no attention to one another outside of
the time of the breeding season. Occasionally there is an excep-
tion to this. The sexual instincts of the green frogs are excited
even in winter when the frogs are fed. Also, on occasions, Rana
pipiens and Rana onca will snap at the head of a companion frog
who has taken a worm that he^ was trying to capture. Whether
this is an exhibition of anger, or the frog is still trying to get
the moving worm which is gradually disappearing and finally
disappears in the other frog's mouth, is a question not easily
settled. Judging from the general meekness of toads and frogs,
it would seem more probable that the latter explanation is the
correct one.
XII. Geographical Distribution.
The Tailless Batrachians are widely distributed. Toads, or
representatives of the genus Bufo (about 100 species), are
found all over the world except in Australia and Madagascar.
The genus Hyla, the largest among the Salientia (150 species),
is almost cosmopolitan in its distribution, being found every-
where except in Africa. The genus Rana (140 species) has a
range extending all over the northern world, though it is prac-
tically lacking from Australia, Africa, and South America.
Most of the North American Salientia belong to these three
genera, Bufo, Hyla, and Rana. There are only four genera
(Ascaplus, Scaphiopus, Acris, and Clorophilus ') peculiar to the
continent, and of these, two (Ascaplus and Acris) possess a single
species each, and one of these (Ascaplus) has, as far as known,
an unusually limited range.
1 chorophilus has one representative in the Neotropical realm (Peru).
35
Introduction
*
The more specialized a race of animals and the more per-
fectly it is adapted to life in a given haunt, the more dependent
is its distribution on the physical features of a continent. The
Salientia, though members of a relatively generalized Class, are
in several respects most highly specialized; and they are illus-
trations of such perfect adaptation that they are helpless in the
face of any condition radically different from those of the chosen
environment.
For instance, they are cold-blooded, and so cannot live in
extreme northern latitudes or in the highest altitudes, because of
the attendant decrease in metabolism with lowered tempera-
ture. (See p. 15.) To a large extent, they breathe through the
skin and absorb water through the skin, hence they must live
in moist situations. They have not endurance enough to mi-
grate even short distances over dry regions. Again, no Batra-
chian can live in salt water,1 and not only is salt poisonous to
them, but lime is, also. Therefore they can neither live in lime-
stone regions or in those impregnated with salt, nor can they
cross such regions.
Thus the North American Salientia must be dependent on
the physical features of the North American continent. We
shall not expect to find them north of a line of o° C, annual mean
temperature, because just north of this the ground remains frozen
the year through, except at the surface. We shall not, more-
over, expect to find as many species for some distance south of
this limit as there are in the southern part of the continent. We
shall not look for them in the bordering salt marshes, gulfs, and
bays, nor in Salt Lake nor on the salt plains of the West. There
must be relatively few of them on the dry Western plains, in the
Rocky Mountains, and in the desert and plateau regions of Cali-
fornia, Nevada, Utah, Arizona, Mexico, New Mexico, and Texas.
Also, the species living in these latter places must be the species
least dependent on moisture, namely the Toads; or those that live
in deep burrows, never leaving these burrows except during rain
(the Spadefoot Toads). We shall not expect to find tree frogs
(Hylidae) in treeless though fertile regions, such as the prairies of
the Middle West. However, this point is less certain, since the
condition is less vital. Moisture and other conditions being right,
tree frogs can adapt themselves to life on the ground, and may
1 Certain species can endure water with i% salt; sea water has about 3.2%.
36
Distribution
suffer retrogression in the structures which facilitated arboreal
habits.
The distribution that we should expect from the physical
features of North America is exactly the one we find on a study
of its Salientia. The thermal barrier to their spreading gives
only a few species to southern Canada. Very few species are
reported from the Western plains and Rocky Mountain region;
among them are the burrowing Spadefoot Toads, which are al-
most peculiar to the region. The dry plateaus of the Southwest
yield mainly toads, some six species. The tree frogs are almost
wholly limited to southern and southeastern regions, with emi-
nent exceptions, such as Acris gryllus, the Cricket Frog, which
has the disks of the toes reduced, and may be found on the ground
either in forest regions or prairie districts. The riches of the
continent in genera and species of Salientia are found in the
moist forest-covered southeastern United States, in Florida, the
Gulf States, and eastern Texas. The northern part of the Pacific
Slope west of the Sierras also has some abundance of species.
A comparative study of the distribution of living and ex-
tinct animals, together with a study of the geological history of
the world, has resulted in a division of the globe into faunal re-
gions, each of which has its subregions. The western hemisphere
has a tropical region (Neotropical) at the south, made up of South
America, Central America, the West Indies, and Mexico. A
boreal region at the extreme north consists of Canada from New-
foundland to Alaska, with a southern boundary corresponding
in general to the northern outline of the United States (the main
exceptions/to this correspondence are due to southerly extensions
along the mountain chains). The stretch of temperate America
between these two is the austral l region, which is very nearly
confined within the limits of the United States.
The Austral region has been divided into life zones that
stretch across the continent south of the boreal zone from coast
to coast. Their boundaries are very irregular. Along the east
and west coasts the southern Austral zones penetrate far north-
ward, and in the high altitudes of the eastern and western
mountain districts the more northerly austral zones, and the
Boreal also, reach long arms southward. The eastern wooded
1 The Austral and Boreal of Merriam (1892) correspond to the following: Nearctic of Slater
(1858); Medio-columhian and Aqulonian of Blanford (1890); Sonoran and Holarctic of Lydekker
(1896); Medio-columbian and Holarctic of Cope (1896).
37
Introduction
portions of the austral zones, counting from north to south,
are known as the Alleghenian, Carolinian, and Austroriparian
faunas, respectively. In a consideration of the distribution of
the Salientia the first two may be taken together for the
sake of convenience and called the Eastern subregion. The dry
portions of the austral zones from the elevated plains to the
west coast are known as the Transition, Upper Sonoran, and Lower
Sonoran faunas. '
The Eastern subregion presents throughout similar con-
ditions of environment for the Salientia. Everywhere are fertile
fields or prairies, extensive wooded tracts, and a multitude of
lakes and ponds, rivers and brooks, all affording suitable haunts
and an abundance of insect food. Because of the thermal con-
ditions, there are more species near the southern limits, and
they diminish in number toward the north. This part of the
continent is the home of the genus Rana, possessing eight species.
The species distributed throughout the extent of this sub-
region are as follows: Rana clamitans, Rana palustris, Rana pi-
piens, Rana sylvatica, Bufo americanus, Hyla versicolor, and
Hyla pickeringii. Species not found outside its boundaries are
Rana palustris, Rana sylvatica, Rana virgatipes, Bufo fowleri, and
Hyla evittata. Bufo fowleri is reported only from Massachusetts,
Rhode Island, and New York near the coast; Hyla evittata, Hyla
andersonii, and Rana virgatipes are found only in the country
east of the Alleghenies, New Jersey to Virginia.2 A few species
found in a more or less limited section of this subregion are re-
ported from other subregions also; such are, Cboropbilus nigritus
triseriatus, Hyla andersonii, Acris gryllus, and Scaphiopus bol-
brookii.
The boreal region has but few representatives of the Tailless
Batrachians. At the east it has Rana septentrionalis peculiar to
itself and gains Rana clamitans, Hyla pickeringii, Bufo ameri-
canus, and a few others from the austral zones just south. At
the west it has Rana cantabrigensis and its subspecies latiremis,
Bufo boreas, Bufo bemiophrys, and Choropbilus n. septentrionalis.
The Austroriparian subregion consists of the southeastern
United States, i. e. the coast region south from isothermal 77°
!For boundaries of Mcrriam's Life Zones, see chart in Bulletin No. 10, U. S. Department of
Agriculture.
2 The eastern part of the Carolinian division of Verrill or the Cisalleghenian division of Cope.
38
Distribution
(Norfolk, Virginia), and those states bordering the Gulf of Mex-
ico, Georgia, Florida, Alabama, Mississippi, Louisiana, and the
eastern one-third of Texas. It also contains the country along
the Mississippi to southern Illinois. West of the Mississippi, its
boundary line extends southward from Missouri to the mouth of
the Rio Grande in Texas.
This subregion has a large number of toads and frogs. It
is the richest of all the subregions in members of the Hylidae. Its
forest areas and many streams, its relatively high temperature
and humid air, make it peculiarly well adapted to the needs of
this group. The subregion has many species peculiar to it ; namely,
Hyla cinerea, Hyla squirella, Hyla gratiosa, Hyla femoralis,
Choropbilus ornatus, Choropbilus ocularis, Chorophilus occidentalis,
Engystoma carolinense, Bufo quercicus, Bufo lentiginosm, Rana
grylio, Rana asopus, and Rana spbenocepbala. Of these species
peculiar to the subregion, many are found in the eastern sec-
tions and Texas as well, but Bufo quercicus and Rana grylio are
not found west of the Mississippi and Hyla gratiosa and Rana
cesopus are not found outside of Florida. Peninsular Florida is a
faunal region distinct from the Austroriparian, but the evidence
of this does not rest largely in the distribution of the Salientia.
Florida has a member of the Cystignathidae (Litbodytes ricordii),
a wanderer from the West Indies.
The Austroriparian overlaps the Sonoran subregion in Texas.
The species that it gains from the Sonoran in this overlapping
are either toads or members of the Cystignathidse adapted to
live in rocky ravines or among limestone cliffs. They are the
following: Bujo compactilis, Bufo debilis, Bufo valliceps, Bufo
punctatus, Bufo I. woodbousei, Litbodytes latrans, and Syrrophus
marnockii. This subregion, though itself poor in toads, gets so
many additions from the two adjacent subregions that it makes
a showing of seven species, possessed mainly by Texas, of
course.
The Sonoran subregion is made up of the Upper and Lower
Austral zones from the Western plains inclusive to the Pacific
Coast. At the south it includes Lower California, Arizona, New
Mexico, and western Texas, as well as the northwestern part of
Mexico. At the north it extends into Montana east of the Rocky
Mountains, to British Columbia between the Rocky Mountains
and the Sierra Nevadas, and not quite as far north as Oregon west
39
Introduction
of the Sierras. It is greatly broken into by the colder and less
dry Boreal and Transition zones that extend southward in the
high altitudes and moister valley regions of the mountains.
The whole subregion is made up of arid elevated plains and
plateaus, of desert regions and mountain ranges. It is notable
for its lack of Batrachia, the only genera of the Salientia at all
well represented being Bufo and Scaphiopus. There is no species
common to the whole Sonoran subregion. Unlike the Eastern
Austral zones, it presents great natural barriers to the spreading
of animal races, and so is cut into divisions, each having its more
or less peculiar fauna.
That part of the subregion east of the Rocky Mountains is
grass-covered, but relatively dry and treeless. It not only has
an arid atmosphere, but it is so elevated that the temperatures
are low. It has but few species of Salientia; two almost peculiar
to it are Bufo cognatus and Scaphiopus bammondii bombifrons.
In Texas this dry region is separated from the moist Austro-
riparian subregion of the eastern one-third of the state by the
boundary of the first plateau (one of the series of three steppes
which present a terraced rise westward from near sea-level to
4,000 feet above). This line passes near Fort Worth, Austin,
and San Antonio, Texas, to the valley of the Rio Grande. In
topographical, climatic, and faunal conditions, western Texas is
as different from eastern Texas as Colorado is from Missouri.
Austroriparian Texas is a plain with low hills of red sand and
with shallow valleys and ravines. It is largely forest-covered,
has a great fertile prairie in the central region, and many swamps
in its southern portion. It is well watered also by the moist
winds from the Gulf. In sharp contrast with this, the Sonoran
portion - - especially the region of the first plateau — is of
peculiar interest. It is dry because of its elevation and because
all prevailing winds are depleted of their moisture in crossing
eastern Mexico or eastern Texas. It is picturesque with deep
forest canyons. The lower levels are covered with buffalo grass
and with various species of cacti and yuccas. Species peculiar
to this district are Lifhodytes latrans and Syrropbus1 marnockii.
But from the surrounding sections of country the following long
list of species is gained: Hyla cinerea, Smilisca baudinii,
Cboropbilus n, triseriatus, Rana areolata, Rana pipiens, Engystoma
1 Lithodytes and Syrrophus are both Mexican genera.
40
Distribution
carolinense, Scaphiopus couchii, Bufo debilis, Bufo pundatus, Bufo
compactilis, and Bufo valliceps.
The country between this western section of Texas and the
Western plains north of it, on the one hand, and the Sierras on the
other, presents little besides barren mountains, desert valleys, and
areas of sagebrush. It possesses two species of toads and one
spadefoot; namely, Bufo I. woodbousei, Bufo cognatus, and Scaphi-
opus bammondii. However, this part of the Sonoran subregion
is penetrated even as far as Arizona and New Mexico by the less
dry Transition zones, and so this part of North America has a
few other species of toads and frogs; these are Rana onca, Rana
pipiens, and Bufo boreas nelsoni. The last is the southern moun-
tain subspecies of Bufo boreas which is found at the north - - both
east and west of the Sierras. Rana pipiens, abundant in eastern
North America, in Texas, and on the Western plains, reaches its
western limit just east of the Sierras.
At the south, in Arizona and New Mexico, in addition to
Bufo cognatus, Bufol. woodbousei, and Rana pipiens, are found Bufo
balopbilus, Bufo alvarius, Bufo punctatus, and Hyla arenicolor,
the latter two entering from Mexico.
The peninsula of Lower California has no species of Salientia
peculiar to it. It reports Rana draytonii, Hyla regilla, Bufo punc-
tatus, Bufo balopbilus, and Scaphiopus couchii.
The narrow stretch of country between the Pacific and the
Sierra Nevada, made up of California, Oregon, and Washington
is arid in its southern portion (Sonoran)1, humid and forested
at the north (Transition). At the south are found Bufo balo-
pbilus, Hyla regilla, Rana draytonii, and, rarely, Rana boylii. The
north has a longer list; namely, Bufo boreas, Bufo balophilus colum-
biensis, Hyla regilla, Scaphiopus hammondii, Rana draytonii, Rana
boylii, Rana pretiosa, and Rana aurora. These are, for the most
part, species not found elsewhere in North America. Some of them
follow the temporary streams of the rainy season into the desert
regions of California and Nevada on the eastern slope of the
Sierras. Hyla regilla, for instance, is often found in springs from
fifteen to forty miles distant from other water, having been
stranded there during flood times of previous years, when the
springs were temporarily in connection with streams.
1 Named Diegan division by Dr. John Van Denbergh, San Francisco.
41
THE FROG BOOK
PLATE V
relatively Smooth
Posterior
Surf
of femur- -
\ v Black Cheek
Heel
Glandular
fold
\ along
Lateral JauJ
Fold
Web
/Vertical Pupil
Fingers with
Adhesive .Disks
s
Cranial Crests
/
/ Parotoid/jUnd
Muzzle
Patch Horizontal
Pupil
4~tH Finger
Palm Tubercle s
Angle of
?
'
r
:'t
'
Head
t
x Inner Sole Tubercle -- — J|^n^4
OL Q 1
uter Oole ••
Tubercle
/
Sacral Hump
' f
Cranial Crest
Paroioid '
Gland
FIG. 12. — To explain fundamental structural characteristics mentioned in the keys.
THE FROG BOOK
PLATE VI
1 3
4
FIGS. 13 and 14 (i and 2). — Scaphiopus holbyookii
Harlan. Raleigh, N. C. Very scared looking when first
awakened. The skin of the side and upper arm is free
from the muscles underneath and drops down in a fold over
the lower arm when the creature is resting. The black
pupil is vertical.
FIGS. I5anu _t> ^3 and 4) — An uncanny-looking fellow
Photographed to show wide front and the unbroken curve
of the jaws, also the black horny thickening of the first and
second fingers. The parotoid gland is round. The ear is
distinct (in front of and below gland).
KEYS FOR THE IDENTIFICATION OF NORTH
AMERICAN SALIENTIA1
(For terms used in Keys, refer to Fig. 12. For method of using Keys, see
footnote 2.)
PRELIMINARY KEY TO FAMILIES
(See page 7 for internal characters determining classification into Families.)
I. Pupil of eye vertical.
A. Inner sole tubercle small; ear not visible; parotoid glands present; size
small. Northwestern United States (Washington).
Ascaphus, of the Family' Discoglossidce. (See p. 51.)
B. Inner sole tubercle large, with extensive cutting edge.
PelobatidcB. (See First Key, p. 43.)
II. Pupil not vertical; either horizontal or round.
A. Parotoid glands always present.
BujonidcB. (See Second Key, p. 44.)
B. Parotoid glands lacking.
1 . Fingers and toes more or less enlarged at tips, to form adhesive disks.
a. Disks T-shaped, small; undersurface of frog smooth.
Cystignathidce. (See Third Key, p. 45.)
b. Disks round, large or small; undersurface more or less granulated.
Hylida. (See Fourth Key, p. 46.)
2. Fingers and toes without disks.
a. Head narrow and mouth small; a fold of skin on top of head behind
eyes; ear not visible; size small (ij inches, or less).
Engystomatidce. See Fifth Key, p. 48.)
b. Head not unusually narrow; mouth large; ear distinct; size 2 inches
or more (except in immature).
Rvnidce. (See Sixth Key, p. 48.)
FIRST KEY. SPECIES OF PELOBATID.E (Spadejoot Toads)
I. Ear distinct; parotoids round, flat; black granulations on top of head; two
curved yellowish lines on back. Eastern North America.
Scaphiopus holbrookii. (See Colour Plate II, also p. 53.)
1 These keys are more or less artificial. Unfortunately, they cannot be based on colour, because
of the great variation and the lack of stability in both colour and colour pattern in the members of
this order. Also, it has been impossible to avoid detail and combine brevity with definiteness, be-
cause of the similarity of the various species.
2 Method oj using Keys. As long as the specimen agrees with the characteristics named in the
Key, read continuously until a technical name is designated at the extreme right. As soon as the
specimen disagrees with the Key characteristics, skip from the point of disagreement to the num-
ber or letter next in order.
In all instances where size is not mentioned, medium size (about 3 inches) is understood.
43
Key
II. Ear indistinct; parotoids lacking.
A. Skin smooth; head arched between the eyes in front, sometimes black
and horny here, and on the end of the muzzle; size small (2 to 2$
inches). Western Plains.
Scaphiopus h. bombijrons. (See Fig. 26, also p. 61.)
B. Skin rough, with closely set tubercles; head not arched between the
eyes in front.
1. Muzzle truncate in profile; short, thick through at end; two or four light
bands on back present or not. North America, west and south of
Rocky Mountains.
Scaphiopus hammondii. (See p. 59.)
2. Muzzle rounded in profile; with or without intricate arrangement of
light bands on back and sides. Southwestern North America.
Scaphiopus couchii. (See Colour Plate II, also p. 57.)
SECOND KEY. SPECIES OF BUFONID^E (Toads)
I. Parotoid glands short, either roundish or triangular.
A. Head rounded above, thick through; cranial crests not present; glands
on tibiae; size large.
1. Muzzle relatively long, sloping in profile; skin very rough, with warts
of many sizes; tendency to arrangement of warts in dorsal rows.
Northern Pacific region.
Bujo boreas. (See Fig. 133, also p. 115.)
2. Muzzle short, steep in profile; skin warty, but relatively smooth on
and between the warts; femur extremely short. Southern Pacific
region.
Bujo halophilus, (See Fig. 121, also p. 113.)
B. Head flat, thin through; skin evenly and closely tubercular.
1. Cranial crests high, sharp-edged, conspicuous. Mexico and Texas.
Bujo valliceps. (See Colour Plate V, also p. 108.)
2. Cranial crests not present; granulations on various parts of head; size
small (two inches). Southwestern North America.
Bujo punctatus. (See Colour Plate V, also p. no.)
II. Parotoids longer, oblique, descending on shoulders.
A. Cranial crests not present; skin evenly tubercular.
1. Head flat and thin through; granulation on muzzle; parotoids unusually
large; toad very small (if inches). Southwestern North America.
Bujo debilis. (See p. 112.)
2. Head thick through, short; femur very short; sole tubercles unusually
large; size medium. Mexico and Texas.
Bujo compactilis. (See Fig. 93, also p. 102.)
44
Key
B. Cranial crests straight; head short; leg short; underparts unspotted.
1. Crests thick, divergent backward from a bony elevation above and
between nostrils; two large sole tubercles, each with cutting edge.
Western Plains and Rocky Mountains.
Bujo cognatus. (See Colour Plate V, also p. 99.)
2. Crests narrow, inconspicuous; skin very tubercular, spinouson legs and
arms; size small (i^ inches). Southeastern United States.
Bujo quercictis. (See p. 104.)
C. Cranial crests curved around eyes; glands on tibiae; size large. Arizona.
Bujo alvarius. (See Colour Plate V, also p. 106.)
III. Parotoids oval (sometimes kidney-shaped in C), extending straight backwards
from the posterior angle of the eye.
A. Head long (three and a half times in total length); cranial crests greatly
elevated, and swollen into knobs behind; underparts unspotted.
Southern United States.
Bujo lentiginosus. (See Colour Plate IV, also p. 89.)
B. Head very short (five times in total length); cranial crests variable,
usually parallel on a raised occiput; underparts unspotted, except on
breast; sole tubercles large; size large. Rocky Mountain region and
southwards.
Bujo 1. -woodhousei. (See Colour Plate IV, also p. 91.)
C. Head medium in length (four times in total length); cranial crests di-
vergent behind; warts often large, and arranged singly in dorsal spots;
underparts spotted. North America, east of the Rocky Mountains.
Bujo americanus. (See Colour Plate III, also p. 63.)
D. Head short (four and a half times in total length); cranial crests variable,
usually parallel; warts never very large, usually arranged several in
each dorsal spot; underparts unspotted. Eastern United States, near
coast.
Bujo fowleri. (See Colour Plate IV, also p. 93.)
E. Head short (four and a half times in total length); muzzle vertical in
profile; cranial crests parallel; no crests behind eyes; tendency to
arrangement of warts in dorsal rows; underparts spotted. North
Dakota and Manitoba.
Bujo hemiophrys. (See p. 98.)
THIRD KEY. SPECIES OF CYSTIGNATHID^E
I. Leg short (length to heel equals length of body forward to ear); muzzle
rounded in profile.
A. Posterior femur spotted; [head long (one-third total length); muzzle
pointed, as seen from above; ear round; size small (i J inches). Texas.
Syrrophus marnockii. (See p. 165.)
45
Key
B. Posterior femur unspotted; head shorter (one-fourth total length) ; muzzle
rounded; ear a vertical oval; size 3 inches. Texas.
Lithodytes latrans. (See Colour Plate II, also p. 163.)
II. Leg longer (length to heel equals length of body forward to eye, or some
point anterior) ; muzzle truncate in profile.
A. Head longer than wide; sides somewhat tubercular; size small (i inch).
Florida.
Lithodytes ricordii. (See p. 164.)
FOURTH KEY. SPECIES OF HYLID.E (Tree Frogs)
I. Disks on fingers and toes of medium or large size (never so small that they
are difficult to discern).
A. Skin coarsely granulated above, like undersurface; fingers webbed; head
broad, short; size 2 to 2^ inches. Florida.
Hyla gratiosa. (See Colour Plate X, also p. 124.
B. Skin rough, with small warts.
1. Posterior surface of femur reticulated with yellow and black; size 2
inches. Eastern North America.
Hyla versicolor. (See Colour Plate VI, also p. 117.)
2. Posterior surface of femur not reticulated or spotted; size if inches
Southwestern North America.
Hyla arenicolor. (See Colour Plate X, also p. 122.)
C. Skin smooth, or nearly so.
i. Posterior surface of femur spotted or blotched.
a. Head short, relatively narrow; body long; white spot under eye
and one at arm insertion; a black spot on shoulder; size 2 to
2§ inches. Mexico and Texas.
Smilisca baudinii. (See Fig. 178, also p. 151.)
b. Head broad, flat; form stout; upper surfaces green, bounded with
line of white (even across wrists and heels); green extends in
scallop on throat; size if inches. New Jersey and South
Carolina.
Hyla Andersonii. (See Colour Plate VII, also p. 131.)
c. Muzzle pointed, projecting much beyond the line of the jaw;
fingers not webbed; an oblique cross on the back; size i inch.
Eastern North America.
Hyla pickeringii. (See Colour Plate X, also p. 138.)
46
Key
d. Muzzle rounded, projecting but slightly beyond the jaw; no light
spot under eye, nor distinct line along jaw; fingers slightly
webbed; there may be a pattern of spots and bars similar to
that of Hylaversicolor (Fig. 134); size i£ inches. Southeastern
United States.
Hyla jemoralis. (See p. 150.)
2. Posterior surface of femur not spotted.
a. Frog long and slender; colour plain, i.e. no evanescent pattern of
spots and bars on head, back, and legs; size if to z\ inches.
' (i) Light bands from the muzzle along the sides, also on the tibiae.
Southern North America.
Hyla cinerea. (See Colour Plate X, also p. 126.)
(2) No light bands; colour plain green above, white below.
Virginia,_Maryland.
Hyla emttata. (See Fig. 161, also p. 128.)
b. Frog not unusually long and slender; light line along jaw (im-
mediate edge of jaw dark).
(1) Form robust; head thick through; canthus rostralis very
prominent; back marked with evanescent pattern of
bands and elongated spots; size i£ inches. Pacific Slope.
Hyla regilla. (See Colour Plate VIII, also p. 134.)
(2) Form more delicate; head not so thick through; canthus
rostralis well marked, but not sharply angled; back marked
with evanescent pattern of rounded spots; size i| inches.
Southern United States.
Hyla squirella. (See Colour Plate X, also p. 148.)
II. Disks on fingers and toes so small that they are scarcely discernible.
A. Skin rough; webs very large; muzzle long and pointed; legs long; size
i inch or less. North America, east of Rocky Mountains.
Acris gryllus. (See Fig. 184, also p. 153.)
B. Skin smooth; webs minute, or lacking.
1. Muzzle truncate in profile, long, slender; upper jaw edged with white;
legs very long; size under i inch. Southeastern United States.
Chorophilus ocularis. (See p. 162.)
2. Muzzle rounded in profile, slightly projecting beyond line of jaw.
a. Posterior surface of femur unspotted.
(i) A light line along jaw; usually longitudinal bands on back, the
middle one forking posteriorly; size i inch, or slightly more,
(a) Leg to heel equals total length.
Head long.
Chorophilus nigritus. (See p. 157.)
47
Key
Head short.
Chorophilus n. jeriarum. (See Fig. 185, also pp. 157 and 160.)
(b) Leg shorter (length to heel equals length of frog forward
to eye) ; head long. Middle and Western United States,
east of the Rocky Mountains.
Chorophilus n. triseriatus. (See pp. 157 and 160.)
(c) Leg short (length to heel equals length forward to shoulder
or ear) ; head long. Northern North America.
Chorophilus n. septentrionalis. (See pp. 157 and 160.)
b. Posterior surface of femur spotted; a light blotch above the dark edge
of the jaw; leg short (length to heel equals length forward to
ear or eye); size ij inches. Southern United States.
Chorophilus ornatus. (See p. 161.)
FIFTH KEY. SPECIES OF ENGYSTOMATID^E (Narrow-mouthed Toads)
I. Two large sole tubercles; toes with short webs; muzzle short in front of
eyes (less than twice the longitudinal diameter of the eye); size ij
inches. Texas.
Hypopachus cuneus. (See Colour Plate II, also p. 169.)
II. One small sole tubercle; no webs; muzzle in front of eyes longer (more
than twice the longitudinal diameter of the eye).
A. Skin very smooth; form slender; head to shoulder one-third total length
size i inch. Texas.
Engystoma texense. (See Fig. 193, also p. 168.)
B." Skin finely tubercular; form stout; head to shoulder one-fourth total
length; size i\ inches. Southern United States.
Engystoma carolinense. (See Colour Plate II, also p. 166.)
SIXTH KEY. SPECIES OF RANID^E (Frogs')
I. Lateral folds present.
A. Skin with longitudinal folds between the lateral folds; definitely outlined
spots on the back and sides; leg to heel equals or exceeds total
length.
1. Spots squarish; undersurfaces of legs bright orange-yellow. Eastern
North America.
Rana palustris. (See Colour Plate XIII, also p. 188.)
2. Spots rounded.
a. Head long (two and a half times in total length) ; circular white spot
at centre of ear; spots on back not outlined with light. Southern
States.
Rana sphenocephala. (See Colour Plate XII, also p. 186.)
48
Key
b. Head shorter (three to three and a half times in total length);
spots outlined with light. North America, east of the Rocky
Mountains.
Rana pipiens. (See Colour Plate XI, also p. 171.)
B. Skin corrugated with elongated warts between the lateral folds and on
the sides; definitely^outlined rounded spots on back and sides; length
of leg to heel not as great as total length.
1. Head long (two and a half times in total length). Florida.
Rana asopus. (See Colour Plate XIV, also p. 193.)
2. Head shorter (one-third total length). Southern United States.
Rana areolata. (See Fig. 223, also p. 192.)
C. Skin relatively smooth between the lateral folds.
1. Ear of male larger than eye; legs short; no black cheek-patch.
a. With definitely outlined spots on back and sides; size small (2$
inches); web large. Nevada, Utah.
Rana onca. (See Colour Plate II, also p. 196.)
b. Without pattern of spots; size 3^ or 4 inches. Throat of male yel-
low. Eastern North America.
Rana clamitans. (See Colour Plate XIII, also p. 198.)
2. Ear of male not larger than eye; legs long; black cheek-patch usually
present.
a. With red in the colouration.
(1) Leg to heel equal to total length; skin unusually smooth.
Northern Pacific region.
Rana aurora. (See Colour Plate XIV, also p. 216.)
(2) Leg to heel not equal to total length ; skin may be tubercular
in old specimens; size large. Pacific region.
Rana draytonii. (See Colour Plate XV, also p. 213.)
b. No red in the colouration; brown or grey.
(1) Length of leg to heel exceeds total length. Eastern North
America.
Rana sylvatica. (See Colour Plate XIV, also p. 205.)
(2) Length of leg to heel just equals total length, or is less than
total length. Northern United States and Canada.
Rana cantabrigensis. (See p. 211.)
D. Skin very tubercular over the whole upper parts; webs conspicuously
large and broad.
i. Leg short (length to heel equal to length of body forward to car); sole
of foot rough with tubercles; eye set obliquely. Northern Pacific
region.
Rana pretiosa. (See Colour Plate XVI, also p. 218.)
49
Key
2. Leg long (length to heel equal to total length); ear obscure, covered
with tubercles; size small (2^ inches). Pacific region.
Rana boylii. (See Colour Plate II, also p. 221.)
II. Lateral folds not present; ear of male larger than eye; legs relatively short;
webs large.
A. Webs quite to the tips of the toes; head long (two and a half times in
total length); size large (4 to 5 inches). Southeastern United States.
Rana grylio. (See Fig. 269, also p. 226.)
B. Webs leave one joint of fourth toe free; body stout.
1. Head narrow; size medium. New York to Minnesota and Canada.
Rana septentrionalis. (See p. 224.)
2. Head broad; size very large (7 to 8 inches). Eastern North America.
Rana catesbiana. (See Fig. 276, also p. 227.)
C. Webs shorter (two joints fourth toe free); head narrow, long; size
small (2^ inches). New Jersey.
Rana virgatipes. (See Colour Plate XIII, also p. 222.)
COLOR PLATE II
Fig. i. — Hypopachus cnneus Cope. Brownsville, Texas. May
be gray or warm shades of brown. There is much red on the con-
cealed anterior surface of the femur.
Fig. 2. — Engystoma carolinense Holbrook. Raleigh, N. C.
Fig. 3. — Lithodytes latrans Cope. Helotes, Texas.
Fig. 4. — Scaphiopus holbrookii Harlan. Providence, R. I.
Fig. 5. — Scaphiopus couchii Baird. Brownsville, Texas. This
spadefoot may be gray, green or brown.
Fig. 6. — Rana onca Cope. Las Vegas, Nevada. The spots are
evanescent in character ; they may be outlined with light
or not.
Fig. -j.—Rana boylii Bd. and Gird. Mill Valley, Cal. This is
the Yellow-legged Frog of California.
Refer to Index to locate descriptions.
THE FROG BOOK
COLOR PLATK II
-
COPYRIGHT, 1906, BY DOUBLEDAY, PAGE dt COMPANY
FAMILY I. DISCOGLOSSID/E: THE DISCO-
GLOSSOID TOADS1
THE AMERICAN DISCOGLOSSOID TOAD
Ascapbus truei Stejneger
IDENTIFICATION CHARACTERISTICS
Colour: Dull reddish brown, with a few indistinct blackish
markings on the back. *sA dusky band between the eyes. The
top of the head in front of this band pale reddish grey narrow-
ing in the midline in front and bordered on each side below the
line of the canthus rostralis by a band of black. This black band
extends backward through the eye to the shoulder along the lower
border of the parotoid gland. A black spot below the arm in-
sertion. Posterior surface of arm irregularly spotted. Femur,
tibia, and under side of foot edged by an irregular dark band
which is sometimes edged with white. Underparts light, clouded
with dark, especially across the breast. Fingers and toes tipped
with light.
Measurements: Size small; i.e. length i finches. Head slightly
broader than long. Nostril nearer to the eye than to the tip of
the muzzle. Space between eyes equal to width of eyelid. Arms
and legs relatively long; arm, I inch; leg (total length), 2\
inches. Length of leg to heel equals length of body forward to
eye. Tibia longer than femur.
Structure: Skin granular, slimy, wrinkled, and irregularly
warty above. Smooth and wrinkled below. Parotoid gland
elongated, extending from the eye backward toward the shoulder.
A narrow elongated gland on the side, corresponding in position
to the lateral fold of frogs. Head flat ; muzzle elongated, abruptly
descending on the sides, obtusely pointed in front. Canthus ros-
tralis prominent. Ear hidden. Fingers long and slender; three
palm tubercles, no tubercles under the joints. Foot but slightly
webbed; no tarsal fold; inner sole tubercle medium in size; no
tubercles under the joints.
Range: One specimen only of Ascaplus truei has been found.
Humptulips, Washington, 1897.
1 Refer to pp. 7, 8, and 43.
S1
The American Discoglossoid Toad
This curious little batrachian (a member of the Discoglossidae,
(see p. 8) is the lowest known form of the Salientia in North
America. In fact, no other Discoglossoid toad has been found
in the Western Hemisphere, and the discovery of this one in
1897 marks one of the most important steps in the history of the
Batrachology of North America.
Although having the form of the Tailless Batrachian, and
many of its structural characteristics, such as parotoid glands
and a tongue free behind, it has a skeleton showing the funda-
mental features in a primitive condition, as in the Tailed Batrach-
ians or Salamanders. It thus supplies an important item in the
story of the evolution of the Salientia. (See p. 14.)
The geographical distribution of the Discoglossoid toads has
been most interestingly worked out by Dr. Leonhard Stejneger,
of the National Museum.1 He makes the region southeast of the
Himalayas, in Asia, the original home of the family. From here
they radiated to New Zealand, in early Cretaceous times, to west-
ern America (over the land bridge that existed between Asia and
North America) in upper Cretaceous times, and to western Eu-
rope in early Tertiary times. Curiously enough, although at
the moment of publication of his theory no Discoglossoid toad
had ever been found in the region indicated as the centre of ra-
diation, a new species 2 was announced from there one month
later by Boulenger.
1 1905. A R&ume' of the Geographical Distribution of the Discoglossoid Toads, in the Light
of Ancient Land Connections. Leonhard Stejneger. American Geographical Society, vol xxxvii, No.
2, pp. 91-94-
Oct. 20, 1905. Science, p. 502. The Geographical Distribution of the Bell-Toads. Leonhard
Stejneger.
2 Bombina maxima Boulenger. Tong Chuan Fu, province of Yunnan.
FAMILY II. PELOBATID/E: THE SPADEFOOT
TOADS l
THE HERMIT SPADEFOOT
Scapbiopus hoibrookii Harlan
IDENTIFICATION CHARACTERISTICS
Colour: Greenish, yellowish, or ashy brown above, with or
without a curved line of yellow extending backward from each
eye. (See Fig. 17.) Iris golden. Light yellow colour about upper
jaw, on sides, and on outer margins of the legs and arms. In
the case of the female, the yellow is replaced by yellowish white.
The under parts are dingy white, becoming purplish posteriorly.
(For colouration, see Colour Plate II.)
Measurements: Size somewhat below medium, i. e. length i\
inches. Female not much larger than male. Body stout and toad-
like. Head large and with very wide front. (See Fig. 15.) Lower
leg shorter than upper leg. Legs short; i. e. length of leg to heel
about equal to length of body (to posterior margin of ear). (See
Fig. 17.)
Structure: Skin relatively smooth, though close inspection
shows small tubercles plainly visible on back and sides. No bony
crests on the head. The thin skin is completely adherent to the
cranial bones and is penetrated by small black bony granules.
The eyes are exceedingly prominent; pupil vertical. Ear dis-
tinct, smaller than the eye. The upper jaw lacks the indenta-
tion common among toads. (See Fig. 1 5 and compare with Fig.
no.) The parotoid glands are small and round. (See Fig. 16.)
The inner tubercle of the sole is a large black spade-like process;
there is no outer sole tubercle. (See Fig. 19.)
Range: Scapbiopus hoibrookii is found in every part of
eastern North America, including Texas and Florida. It is re-
ported from Martha's Vineyard, which fact, as Cope says, may
indicate the late separation of that island from the mainland.
A strange weird-looking creature is the Hermit Spadefoot
when he is turned out of his ground burrow. At first sight he
1 Refer to pp. 7, 8 and 43.
S3
Pelobatidae
looks like a small brown ball of earth, but almost immediately
air is expelled from the lungs, so that the inflated sides collapse,
and two elevations rise at the smaller end and become two round
staring eyes (Fig. 13) of so brilliant a gold that they seem wholly
out of place in such a dusky surrounding. In the centre of each
golden circle is a very narrow black vertical slit, which gradually
broadens into an oval black pupil. Awkward hands are lifted
one at a time and rubbed over the eyes. The Spadefoot, now
quite awake and alert (Fig. 1 5) begins trying to escape. He does
not stealthily creep away as do many of the toads; he does
not startle one with a prodigious leap, as do the frogs and tree
frogs. He begins sinking out of sight into the soft earth, and in
less time than it takes to tell it, has wholly disappeared from view.
If we wait a moment and then remove the earth carefully
from over him, we find him cosily settled in his usual hibernating
position. His head is bent downward so that his chin rests on
his front feet. These feet and the back ones are tucked closely
under him, his eyes are shut, and his sides are puffed out because
of the expansion of the lungs within.
If we take him out and put him on a piece of paper or some
other solid substance, instead of directly on the ground, we can
observe the backward digging movement of the feet and can hear
the scratching and scraping as the horny parts of the feet (Fig. 19)
are vigorously rubbed against the hard surface. By this time,
however, the creature is thoroughly awake and greatly frightened.
(Fig. 1 8.) Finding its digging efforts unavailing, it creeps stealth-
ily forward or hops in regular toad fashion for a short distance,
and then tries again to dig a burrow in which to hide.
The Hermit Spadefoot is not well known. It burrows into
the ground and sleeps days or weeks, perhaps years, at a time.
A gravedigger once found one 3 feet 2 inches from the surface
of the ground, with no evidence of entrance or exit to the burrow.1
The Spadefoot is seldom discovered in gardener orchard; but
it is certainly true that if a Spadefoot toad were turned out of
its burrrow by the plough, the casual observer would not give
it a second glance, because it looks so much like an ordinary
dingy brown toad, unless one sees its eyes.
The mystery surrounding the life of the Spadefoot is increased
by the fact that when he does leave his burrow it is always under
1 Vol. I, No. 7, Bulletin of Amer. Museum of Nat Hist., Col. Nicholas Pike.
54
The Hermit Spadefoot
cover of the darkness of night. Toads are lovers of the dusk;
the Spadefoot is wholly nocturnal in habit, a fact which might
be inferred from the cat-like vertical pupil of the eyes.
There is one time when the Spadefoot Toads make them-
selves conspicuous. This is when they come out of their bur-
rows, hundreds strong, and go to the ponds or temporary pools
for the purpose of depositing the eggs. This time is usually in
the spring,1 and is always coincident with a very heavy rain-
storm or with a long-continued, warm drizzling rain. They are
likely to remain in the pond only one night, or two at most, but
during this time keep up a continual chorus of loud calls that can
be heard at a great distance. The Spadefoot Toads swim and float
awkwardly, sit on projecting stones and tufts of grass, and in fact
turn the dead and shallow temporary pool of the meadow into
a scene of great activity. The females make a low, grunting
sound; the loud calls are given by the males only. Each call
is relatively short, and is somewhat louder than that of the com-
mon toad. Its carrying power is greatly enhanced by a throat-
sac which acts as a resonator. This sac swells to three times the
size of the creature's head. The call is often started while the
Spadefoot is floating with his body horizontal and his legs
outstretched. Increase of air in the throat region changes the
centre of gravity so that the body is thrown forcibly and instan-
taneously into a vertical position in the water.
The chorus is somewhat unusual in quality, and when it is
heard at night it takes on an extra note of weirdness from the
surroundings. An idea of its effectiveness can be gained by read-
ing the accounts of it given by various observers. Now it is de-
scribed as "a loud bellowing," again it is said to consist of "weird
plaintive cries," or of "shrill ear-piercing groans." One writer
calls it "a deafening, agonizing roar, hoarse and woeful."
After the eggs are laid, the Spadefoot Toads disappear entirely,
leaving no trace of their hiding-places. In fact, it is not known
whether they burrow in the neighbourhood of low land where
temporary pools are likely to form, or whether they go a con-
siderable distance into higher land before they burrow. At any
1 F. S. Smith, April 29, 1879. New Haven, Conn.
C. C. Abbot, May, 1874. April 10, 1884. June 26, 1884. Trenton, N. J.
C. W. Hargitt, August 10, 1887. Martha's Vineyard.
C. S. Brimley, May, 1895. Raleigh, N. C.
55
Pelobatidae
rate, these facts are well authenticated: They disappear with never
a stray one left behind, and they may not appear again in the
same locality for many years.
They leave the pond filled with eggs — strings of eggs fas-
tened to grass blades or stretched from weed to weed. In most
of the cases observed, the ponds dried up before there was time
for the development of the eggs, and in all cases the devel-
opment seemed to be hastened because of the drying of the pond.
The eggs hatch in from seven to fifteen days, according to the
temperature.
The tadpoles appear velvety black in water, but when ex-
amined closely are rich brown in colour. They are short and
stout-bodied, with narrow, spotted tails. In about two weeks
after hatching, the delicate thread-like arms appear and the ab-
sorption of the tail begins. They leave the water while the tails
are still quite long. Like toads, they will drown if they have
no opportunity to get out on land. The tadpoles may show the
yellow dorsal lines characteristic of the adults even before the
front legs appear.
The first instinct of the little Spadefoots is to burrow. The
feet are supplied with the apparatus for digging, although it is
not as hard and horny as it becomes later, and so necessitates
making the burrow in soft earth. The diminutive creatures have
been observed to feed greedily on flies and young spiders.
One observer records an exodus of thousands of young Spade-
foot toads from their native pond. For hours they "trudged"
in leisurely fashion up a steep hill, apparently not stopping for
food on their way.1 When picked up in the hand, they made a
faint squeaking noise.
The adult Spadefoot is an unintelligent and somewhat un-
canny-looking creature — its appearance quite matching its mys-
terious habits and underground life. (Fig. 15.) The wide, rounded
head bears two extremely prominent eyes set far apart. The ver-
tical pupil has a narrow downward-projecting slit at the lower
end. The iris has a black triangular indentation at its anterior
margin. One-fourth inch behind the eye and about equalling
it in size, is a round parotoid gland.
The skin is smooth, compared with that of the common toad,
1 The life history of the Hermit Spadefoot is taken from the accounts of various observers cited
in Bibliography, pp. 241 to 250-
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but on close examination is seen to be finely warty. While at-
tached firmly in the region of the head, it is loosely attached on
much of the body, and wrinkles at every turn. (See Figs.
1 6 and 18.) When the Spadefoot is in resting position, the loose
skin of the upper arm extends in a fold down over the lower arm
and hand. (See Fig. 13.)
The fingers are thickened at their tips; there is a black, horny
thickening of the upper surfaces of the two inner fingers. (See Fig.
15.) The foot is depressed, and the skin covering it is thick and
somewhat horny in character, converting the foot into a living
spade. At the base of the shortest toe is a long, black, horny
spur to aid in digging. The same black horny substance is seen
at the tip of this inner toe. (See Fig. 19.)
Except during the breeding season, the Spadefoot is found
only by accident. It sits in its burrow, showing only its peculiar
golden eyes at the doorway. The turnip-shaped burrow is about
six inches long and somewhat oblique in position. The earth on
the interior is hard and smooth, packed into this condition by a
continued energetic turning-about on the part of the owner of
the burrow. The Spadefoot is solitary in habit, and will not tol-
erate the presence of a neighbour in the burrow.
SCAPHIOPUS COUCHII, BAIRD
IDENTIFICATION CHARACTERISTICS
Colour: Variable; green, olive, or brown — bright or dull —
of light or dark shade. Streaked or banded more or less irregu-
larly with light (bright yellow or dull yellowish). These bands
may be continuous and symmetrically placed, producing a regu-
lar pattern, or may be so irregular and broken as to give the
appearance of spots only. Small tubercles of the anterior back
and head are black; those of the sides, posterior back, and tibia
may be yellow. Buttocks with white tubercles. Iris metallic
yellow, sometimes reddish. Underparts light, skin transparent
and purplish posteriorly. Hands and feet light-coloured. (See
Colour Plate II, also Figs. 20 to 25.)
Measurements: Size below medium; i. e. length 2 to 2| inches,
Head £ inch long (specimen of 2j inch length). Space between
eyes equals or slightly exceeds width of eyelid. Leg short; length
57
Pelobatidae
to heel equals length of body forward to ear or eye. Tibia shorter
than femur. (Fig. 24.)
Structure: Skin rough, with small tubercles on head, back,
sides, and tibias. Skin of underparts slightly rough, smooth an-
teriorly. Parotoids small, flat, covered with tubercles; indis-
tinct. Head rounded in front; slight indentation in upper jaw.
Muzzle slightly projecting, with gradual slope to the jaw. Ear
round, indistinct. Pupil vertical, with narrow slit in iris below.
Iris has triangular indentation at front. Nostrils nearer to the
end of the muzzle than to the eye; they are directed upwards.
Hand with one large and two small palm tubercles; third finger
longest; first and second black and horny (male). Foot large,
fully webbed, and supplied with a large black inner sole tubercle.
(Fig. 25.)
Range: Scapbiopus coucbii (Baird) is reported from Mexico,
Lower California, and Texas. In Texas, it has been found at
Brownsville, Waco, and Helotes.
This Southern Spadefoot is an attractive and alert-looking
creature, very different from the uncanny, smooth-skinned Eastern
Spadefoot (Scapbiopus lolbrookif) and the Northwestern form
Scaphiopus la, bombifrons. It is often very bright in its colour-
ation and shows habits of jumping and walking instead of con-
stantly burrowing; it would thus seem more adapted to terres-
trial existence than are its near relatives. The adaptations for
subterranean and nocturnal life are well marked, however, in the
development of the inner sole tubercles and in the vertical pupil
of the eye.
There is great variation in the arrangement of the colour.
The bands of light may be so reduced as to give an irregularly
spotted appearance merely. On the other hand, they may be
so broad as to make the creature appear light-coloured banded
with dark. The typical arrangement of the light is as follows:
A curved or V-shaped band between the eyes anteriorly, with the
bend pointing backwards; second and third larger, more elon-
gated V-shaped bands more or less parallel to this, starting back-
ward from the eyelids on the top of the head posteriorly and from
the posterior angles of the eyes respectively. The third meets,
in the midline of the back, oblique converging bands from the
58
The Western Spadefoot
lower posterior sides. In addition, there are lateral bands from
above the ear backward, and conspicuous short ones (usually
seven in number) on the muzzle and side of the head and neck,
extending from above downward to the line of the jaw.
When several of these Spadefoot Toads are kept in captivity,
they protest noisily until they get accustomed to the new en-
vironment. The voice is low-pitched and harsh; the sounds are
made both by the male and female. A vocal pouch, in the case of
the male, expands not only at the throat region, but also at the
sides — over the arm insertion and on the sides of the breast —
giving the creature a broad ludicrous front.
Scaphiopus coucbii was found breeding in the pools at Browns-
ville in July, 1905.
THE WESTERN SPADEFOOT
Scaphiopus hammondii Baird1
IDENTIFICATION CHARACTERISTICS
Colour: Brown or grey, with or without two (or four) curved
dorsal stripes of lighter colour. Tubercles tipped with red or
orange. Muzzle not barred vertically with light (as in Scaphiopus
coucbii). Underparts light, unspotted. Throat of male
black.
Measurements: Size medium or below, i. e. length 2 to 3 inches.
The total length of leg and foot exceeds very slightly the total
length of head and body
Structure: Upper surface closely set with relatively coarse
tubercles. Skin of underparts smooth. Parotoids lacking or ob-
scure. Ear obscure. A fold of skin back of the angle of the jaw.
Outline of jaw from below, acuminate oval (more acute than in
Scaphiopus couchii). Muzzle short, thick, perpendicular when
seen in profile. (Muzzle more truncate and protruding, but less
thick than in Scaphiopus couchii). No canthus rostralis.
Range: Scaphiopus hammondii Baird is widely distributed.
It is found both east and west of the Sierras and also has an ex-
tensive range north and south. It is reported from Mexico, south-
1Spea hammondii Baird, and judging from the type specimens in the National Museum,
Spea hammondii intermontana Cope, also. (Cope's Batrachia of North America.)
59
Pelobatidae
ern California, New Mexico, Texas, Utah, Nevada, northern Cali-
fornia, and Washington.1
This Western Spadefoot resembles Scapliopus coucbii in
having a tubercular skin and the parotoids either obscure or
lacking. It differs in having a more pug-dog expression pro-
duced by the shorter, more truncate, and projecting muzzle; also,
the ear is more obscure. There can never rise confusion in dis-
tinguishing it from Scapbiopus bolbrookii or Scapbiopus bam-
mondii bombifrons, both of which are comparatively smooth-
skinned. The lack of parotoid glands and black granulations
of the head will also distinguish it from Scapbiopus lolbrookii,
and it differs from bombijrons in having the cranium between the
eyes flat instead of arched.
There is considerable variation in colouration and in size in
the species. The pattern of dorsal lines may be present in whole
or in part only, or may be obscured. The northern specimens
attain a larger size than those in southern California and Texas.
This species, like the other Spadefoot Toads, is interesting
because of its adaptation to existence in dry regions. It remains
in subterranean burrows throughout the year except during con-
tinued or heavy warm rains. It is said to be very noisy dur-
ing the breeding season. Young specimens were obtained from
San Diego, California, in early April. They measure three-fourths
inches long, having a blackish skin already covered with reddish
warts, and feet that show the black horny spade well developed.
They have the characteristic thick projecting muzzle and obscure
tympanum.
Scaphiopus bammondii has been known to deposit its eggs in
pools formed by heavy rains, in July and August. It is likely
to appear in gardens and vacant lots in cities as well as in more
isolated country places.
1 San Diego, Olancha, Redding, California; Painted Desert, Arizona; Helotes, Texas; Pyramid
Lake, Nevada; Salt Lake City and Provo, Utah; Fort Walla Walla, Wash.
60
The Spadefoot of the Western Plains
THE SPADEFOOT OF THE WESTERN PLAINS
Scapliopus hammondii bombifrons Cope
IDENTIFICATION CHARACTERISTICS
Colour: Yellowish olive. Muzzle darker through midline.
Indistinct curved dark band on the head between the eyes. Two
curving (more or less parallel) dark bands, extending backward
from the eyes. These bands are made up of closely placed spots,
each spot containing a smooth orange-coloured tubercle at its
centre. Similar spots with orange-red tubercles are scattered
irregularly over the sides and posterior portion of the back. There
may be four distinct light yellow bands running lengthwise along
the back. There may be a dark spot on the canthus rostralis.
Iris golden. Tibia spotted irregularly or vermiculated with dark.
Underparts dingy white, purplish posteriorly; throat blackish.
Measurements: Size small, i. e. length 2 inches. Space be-
tween eyes equal to or greater than width of eyelid. Leg short;
length of leg to heel equal to length of body forward to shoulder
or ear. Tibia not longer than femur.
Structure: Skin smooth and fine in texture, with a few tuber-
cles on the sides, posterior portion of the back, and on the tibias.
Muzzle short in front of eyes (no longer than horizontal diameter
of eye). Outline of jaw as seen from below, acuminate oval.
Truncated muzzle elevated. Eyes face forward and outward;
pupil vertical. Nostrils slightly farther apart than distance
between eyes. No canthus rostralis. Ear indistinct. Top of
head between the eyes anteriorly is horny-looking, also in front
of this beween the nostrils and on the end of the muzzle. It is
not only horny-looking, but it is elevated in two arches from the
front backward. (See Figs. 26 to 30.) Parotoids obscure or lack-
ing. Hands unusually small and fingers short. Whole palm horny,
so that the palm tubercles are not easily made out. Foot exten-
sively webbed, but the webs are deeply indented. Inner sole
tubercle not only large, but greatly extended, so that it is most
effective in digging.
Range: Scapbiopus bammondii bombifrons is typical of the
northern part of the Western plains. It ranges from northern
Texas to Montana. It is reported from Montana, Dakota, Idaho,
and Colorado.
61
Pelobatidae
This Spadefoot is especially characteristic of the elevated
plains of the Western part of the continent. It has the habits
of the Eastern Spadefoot (Scapliopus holbrookii), in that it bur-
rows during the greater part of the year, only coming out during
heavy and continued rains. In its range it is very abundant,
and so when it does appear, every ditch and pool of water may
show representatives. Being dependent on rain, its breeding
season varies greatly from year to year. Cope observed speci-
mens in Montana in which the metamorphosis was completed
August 20th. He observed in Idaho the full-grown, fat larvae
with the tails unabsorbed trying to feed upon animal food. They
were in small burrows that they had made in the wet sand some
distance from the lake margin. Some of them, in which the meta-
morphosis of the mouth had proceeded so far that there was a
wide gape, had whole grasshoppers l in their mouths or partially
projecting from them. This observation also was in August.
This Spadefoot croaks vigorously when taken in the hand.
The throat swells into a resonating pouch wider than long, and
widest just back of the jaws, in a line with the front of the arm
insertions. The creature is very active and alert in habit. It
burrows into sandy soil dexterously and rapidly, using the feet
and legs to good effect. The curved horny 'elevations on the
head combined with the shortness and thickness of the muzzle,
produce a most curious pug-dog expression. The horny arches
are probably closely connected with the burrowing habit, the
head being used to keep the burrow open in front. The amount
and hardness of this horny growth of the epidermis of the head
varies in different specimens: there may be a thin dark-coloured
layer only, or the horn may be thick and as black and hard as is
the inner sole tubercle. In some specimens this black horny sub-
stance is found not only on the head but also in a broad dorsal
band.
• Cahptenus spretus.
62
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THE AMERICAN TOAD
Bufo americanus Le Conte
IDENTIFICATION CHARACTERISTICS
1. Colour: Extremely variable; usually yellow-brown, light
or dark in shade, with or without patches and bands of lighter
colour. A light vertebral stripe may be present. There may
be much bright red and yellow on the warts. There are likely
to be four irregular spots of dark rich colouring along each side
of the vertebral line. Under parts light, with few or many
spots. (See Fig. 52.) Throat of male, black. Female much
brighter and more variegated in colour than male. (Fig. 47.)
(For colouration, see Colour Plate III.)
2. Measurements: Male 2 J to 3 inches in length; female much
larger. Head large; its length contained 4 to 4^ times in total
length. Legs medium in length — length of leg to heel equal to
length of body forward to eye.
3. Structure: Skin conspicuously warty. Parotoid glands
medium in size, more or less reniform in shape; situated just back
of eye. Straight, narrow, diverging bony ridges extend back-
ward between the eyes; each meets at right angles a second bony
ridge extending back of eyes to a point above ears. The first
ridge extends a little beyond the point of meeting with the second.
There is little or no evidence of a ridge extending between the
end of the second ridge and the parotoid gland. (See Fig. 48.)
Inner sole tubercle of foot conspicuous because of size and black
colour. Outer tubercle smaller. (See Fig. 44.)
Range: Bufo americanus is the common toad east of the
Rocky Mountains from Mexico to the Great Bear Lake. It
shares the Southern States with Bujo lentiginosus, and southern
New England and New York with Bufo fowleri. The species
varies considerably in different parts of its range, the variation
showing itself in intensity of markings, prominence and arrange-
ment of the cranial crests, and in size.2
1 Refer to pp. 7, 9 and 44.
2 Bujo copei Henshaw and Yarrow (James Bay, type locality) seems to be a small, promi-
nently spotted Bujo americanus, judging from the type specimens in the National Museum. Bujo
aduncus Cope may possibly be Bujo americanus. The type specimen is lost, and the species has not
been rediscovered.
63
Bufonidas
It is the first of May, late in the afternoon.
We stand at the edge of a pond, under a maple
brilliant with its fringes of red keys. A marshy
place at our left is yellow with "cowslips."
Farther back from the water are the broad
spreading leaves of the skunk cabbage and the
unrolling fronds of the cinnamon fern. Every-
where about the margin of the pond the green
arrowhead leaves are just thrusting their pointed
ends above the water; the new red leaves of the
yellow pond-Hies are resting on the surface or
struggling up to it.
Suddenly out in the centre of the pond hun-
dreds of small fish leap from the water to escape
some enemy below, and drop back, making over-
lapping circles of motion that widen and spread
until all is placid again. There is no silence; all
is life. The red wings are indulging in a lively
conversation in the marsh near at hand. The
ever-present green frogs are croaking from the
ooze and immersed brown leaves just in front of
us. They are so near that we can see their yellow
throats and green sides expand again and again
as the explosive calls are repeated.
What is the new sound? Very near at hand,
there is a sweet tremulous call that continues for
several seconds, then stops abruptly. There it is again, but from
another direction, and slightly different in pitch. Now it comes
from all quarters — many voices answering and blending into
harmony.
It is not difficult to locate the singers. They are toads, with
throats distended into conspicuous light-coloured sacs astonishingly
larger than their heads. They are quite unconscious of our
presence as they sit erect in shallow water, showing their bright
eyes and their enlarged throats. (Figs. 31 and 83.)
The sounds are of such quality that they influence us to loiter.
We sit down on the dry exposed roots of the maple to watch, and
to listen to these creatures expressing the glad life within them.
The simplicity and quiet joyousness of it all take hold upon us.
Suddenly there is a slight commotion in the shallow water
64
The unrolling fronds
of the Cinnamon
Fern.
COLOR PLATE III
THE AMERICAN TOAD \Bufo americanus Le Conte.
Providence, R. I.]
Figs, i and 3 represent male toads ; 2 and 4, females.
Fig. i. — So surprised by the suddenness with which they were
removed from their respective places and set down before
the camera, that they retain unnatural positions and sub-
dued expressions for some minutes. The toad at the left
just from its dark burrow (note small pupil) ; the one at the
right from bright sunlight.
Fig. 2. — Delicate coloration possessed just after moulting the
skin.
Fig. 3. — Coloration perhaps most often seen.
Fig. 4. — Bright color often assumed by female when active on
a warm, sunny day.
THE FROG BOOK
COLOR PLATE IIJ
COPYRIGHT, 1906, BY DOUBLEDAY, PAGE &. COMPANY
The American Toad
The shining leaves
and flowers of the
Cowslips. — •
May 1st.
at our left, and out
comes a snake, making
its way along the bank
towards the mass of
golden "cowslips."
But such a queer snake
one never saw. It has two long
legs extending straight out from
the neck. It is the work of but a moment to
stop its course and hold it firmly to see what
strange monster is here. Do you see? The
sna^e ^as Partially swallowed a large toad,
headfirst, and the toad's long hind legs are
extending on each side from the angle of the
snake's jaws. It is one of our singers, too intent
on his singing to see the stealthy approach of his enemy. Pity
wins the day; we must save the toad, although the snake will
lose a good dinner, and probably a well-earned one. So we in-
crease our pressure on the snake slightly, and the toad is released.
With eager hops he proceeds back to the water. The snake goes
on until hidden under the shining leaves and yellow flowers of
the "cowslips." Humbly and thoughtfully we continue our
walk. The crooning tones of the singers in the pond become
more and more indistinct until they are lost altogether, and we
come again into the busy world of men.
In late May, go to the woods, when the new wintergreen
leaves are coming up red. Proceed to
the pond at the edge of the woods, espe-
cially if it be late afternoon. Stand and
look out over the water with its opening
yellow pond-lilies, some of their leaves
still wearing their baby red. See the
brilliancy and delicacy of the colum-
bines that cluster with the ferns at
your right. Look for the broad
leaves and flower-like fruits of
the "cowslips" along the pond
margin at the left. Hear the
emphatic call of the oven-bird at The broad leaves and fl0wer-like fruits
your back, the love notes of the of the Cowslips.— May aoth.
65
Bufonidae
chickadee far away among the trees, and the merry tinkle of the
bobolink in the meadow beyond the blue flags. By this time, how-
ever, you have probably heard sounds from the pond itself. The
explosive note of the Green Frog proceeds from the shallow water;
the purring trill of " the Tree Toad " comes from some spot im-
possible to locate. But listen! The toad's lullaby note ' comes
from the far margin, sweeter than all others if we except the two
notes in the chickadee's spring call. We could never have believed
it to be the voice of a toad if we had not seen and heard on that
first May day. The sustained note is not only high-pitched and
tremulous; it seems to have a dual character,
as though a low note were droned at the same
time that a high one was whistled. Imitate
the call by whistling the upper and at the
same time humming the lower of the following
two notes.1 The imitation may be good
enough to bring response again and again.
If we go to a pond at night, we shall have every opportunity
both to see and to hear toads, especially if we carry a lantern.
Instead of being frightened by the light, they are attracted by
it and may gather about it. If the lantern is set on the ground,
they sometimes try to climb to its top. An especially enthusi-
astic one may sit on the toe of our boot, swell out his throat and
sing. Even taking them into our hands will not quell their ar-
dour at once. They continue to sing even while we take hold
of the distended throat, which is hard from the pressure of the
air within.
If we row on river or lake, pond or park lagoon, some
moonlight night late in May, their voices, which seem somewhat
woeful in the silence of the night, make a fit accompaniment to
the slow dip of oars and the low gurgle of water at the boat's
stern. We are reminded that this song has been compared to
the slow opening movement of Beethoven's " Moonlight Sonata."2
As late in the season as this there will be heard also an occasional
deep bass note from a bullfrog, a loud and somewhat startlingly
weird sound of the night, not at all in harmony with the gentle,
drowsy song of the toads.
1 In late May and June we can hear at the ponds of Rhode Island and Massachusetts the call
of the Fowler's toad. This call is far more conspicuous and much less musical. (See p. 95-)
2 " Familiar Life in Field and Forest." F. S. Matthews.
66
THE FROG BOOK
PLATE XI
FIG. 32. — The toads may be removed to anartificia pond
and the eggs will be laid as though there had been no dis-
turbance.
FIG. 33.— Toad's eggs laid June 12, 1903. Photographed
June 13, 24 hours later. Eggs enclosed in curling, cylindrical
jelly-masses.
THE FROG BOOK
PLATF XII
FIG. 34. Photographed June 15, 1903, three days after
time of laying. The coils are straightening; the jellymass is
much less solid ; the eggs show the head and the tail ends of
the tadpoles.
FIG 35. — Toad tadpoles are hatched June 16, 1903, four
days after the eggs are laid. The jelly-mass is almost wholly
disintegrated.
The American Toad
The American toads are in the ponds from late April until
July. They may appear much earlier if the spring is early. The
males — who alone do the singing — are the first arrivals. Dur-
ing a large part of these months they sing both day and night.
If the season is unduly cold, they may be silent for days or weeks
together, reappearing on the return of a higher temperature.
The eggs which are laid1 in long curling masses (Figs. 33
and 36), (likely to be tangled among the waterweeds and stretched
from object to object in secluded, shallow parts of the pond),
are black above and white underneath. They are arranged in
a single row, in a transparent jelly-like mass cylindrical in shape,
and are fertilised in the water as they are laid. The toads may
be removed from the pond to an artificial one, and the eggs will
be laid as though there had been no disturbance. (Fig. 32.)
The jelly-like substance about the eggs is scarcely visible
when the eggs are first laid, but it swells in contact with the
water until it becomes very conspicuous. Perfectly clean and
transparent in the beginning, it soon becomes discoloured by
the sediment of the water until one may look directly at coils of
the eggs and not see them, because of their resemblance to debris
at the bottom of the pond.
The eggs are small (less than i^ mm. in diameter). Their
number is incredibly high. Various layings counted have yielded
between four and twelve thousand eggs each. If the eggs are
laid early, the development is comparatively slow. But if the
eggs are laid later, when the temperature is more steadily high,
or if they are kept in the warm atmosphere of the house, the
development is remarkably rapid.
Those figured here were laid Friday, June 12, 1903, indoors.
They were photographed on Saturday, twenty-four hours later,
when they were very much increased in size and all the fertilised
eggs were entirely black. (Fig. 33.)
Monday they were photographed again. (Fig. 34.) The
jelly-mass is now much less solid; the coils are straightening, but
still hold their cylindrical shape. The eggs are no longer eggs,
but young tadpoles in which head and tail are easily distinguished.
What is our surprise twenty-four hours later — just four days
'April 14, 1890; April 6, i8
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THE FROG BOOK
PLATE XVI
•
FIG. 44. — The right foot of the toad, photographed from
underneath to show webs and spur. [Enlarged.]
FIG. 45. — In July and August the toad still retains to a
certain extent his desire to sing. He often sits with his throat
partially distended. [Michigan.]
FIG. 46.— A portion or a toad's moulted skin, rescued as
it was being swallowed. The skin of the left half of the back
and of the left hind leg. Photographed from underneath to
show the line of splitting along the under side of the leg and
foot to the horny tip of the longest toe. [Enlarged.]
The American Toad
has been accumulated in the mouth, the toad proceeds to swallow
it with much effort. The eyes above and the throat below are
compressed convulsively several times, then the cavernous mouth
is slowly opened and shut, again and again. Finally, the discom-
fort seems past. The alert look, which tells that the toad is again
awake to his surroundings with all their possibilities, comes back
to the bright eyes; the erect position is resumed; the wet skin
dries; the colour darkens, and our toad is quite himself again.
The process of moulting may easily be observed in the old
toads in July and August after they have left the ponds and taken
up their places in the garden or field. On the whole, this is one of
the best seasons for getting acquainted with the toad. He is very
hungry indeed, for in his arduous life at the pond he has fasted to
some extent. He still retains in a measure his desire to sing. He
often sits with throat partially distended. (Fig. 45.) Sometimes
in the early night he sings.1 His voice is feebler, but not less
sweet than it was a month or more ago.
Hold the toad gently in your hand, so that his hind feet are
without support, and hear him "talk." He is annoyed, and
demands to be released. His tone is not irritated, however. It
is, instead, a gentle chirping sound that reminds one of a newly-
hatched chicken, only that the voice is sweeter. See! the throat
puffs out and the trilled note is given while the toad is in your very
hand. He twists his head about and looks at you brightly. He
pushes with his hands, and wiggles his feet in a helpless fashion.
All the time he is " talking " — the chirping notes coming thick
and fast, while his throat and sides are vibrating rapidly. Again
the throat is extended and the musical trill is continued for a
few seconds, leaving you elated that you have heard, but with a
sense of loss that the sound is so short-lived.
The throat-pouch is a single sac with air entering it from the
mouth through two slits. These slits are on the floor of the mouth,
at each side of the forward end of the tongue. The air enters the
mouth through the nostrils; the mouth is kept closed. The toad
can give voice to its call under water with nostrils and mouth both
closed. In this case the air passes back and forth from throat-sac
to lungs over the vocal cords in the throat. When the call is given
1 1 have heard this feeble note of the toad in August only some half-dozen times. When I first
heard it (the toads were under observation in " moss gardens " in the house), I accredited it to the
snowy tree-cricket, whose voice is so familiar a sound during August evenings.
75
Bufonidse
with great vigour, the air from the side slits in the mouth presses
on the side walls of the throat-pouch with such force as to make
the pouch look as if it were made up of two sacs, i. e. the wall at the
midline is not as forcibly distended as are the side walls.
If we hold a toad in our hands, we realize certain details of his
appearance which we should not have noticed if we had looked at
him at longer range.
The two oval black nostrils are very conspicuous. Each is
situated on a line between the inner corner of the eye and the end
of the muzzle, and is somewhat nearer the former. There may be
rhythmic movements of the membrane bordering the openings
which show that air is being taken in.
The throat also moves rhythmically in and out as if in breath-
ing, but more rapidly than the nostril membranes. Timing the
movement of the throat, we find that the pulsations occur at the
rate of about three per second.1 The movement is confined to the
floor of the mouth and throat, and is, in truth, a swallowing act,
necessary to force the air down into the lungs. The necessity
arises from the facts that the nasal tubes leading from the external
nostrils open into the front part of the mouth (see Fig. 279), in-
stead of far back in the throat, as they do in higher forms, and
that the toad has no ribs, and so cannot have chest movements to
suck the air into the lungs.
The elevated eyes are very brilliant and very beautiful.2
The pupil is a black horizontal oval and is surrounded by a broad
rim (iris) of gold. While we watch, the eyes are shut, both to-
gether or one at a time. The process seems mainly one of making
the eye level with the surrounding surface by lowering it into the
1 The rate varies with temperature and other conditions. It is much slower when the toad is
sleeping or hibernating. The .throat movements may cease altogether for a minute or more at a
time. This occurs when the toad is eating or is " playing dead."
2 The toad's eye is so beautiful that it gave rise in past ages to the fable of the " jewel " of
the toad's head. This jewel was supposed to be a precious stone found within the toad's head. It
acted when worn as a talisman protecting the wearer from all sorts of evil.
Possibly the supposed venomous qualities of the toad gave the toad-stone special value, for the
old theory that " like cures like" was fully believed, and all sorts of poisonous plants and animals
were used as charms and talismans.
The jewel in the toad's head is referred to again and again in literature and history.
" The fayrer the stone is in the toad's head, the more pestilent the poyson in his bowelles."
-Lyly.
" There may be many that ware these stones in Ringes beeing verily perswaded that they
keep them from all manner of grypings and pains of the belly." — Topsell.
76
The American Toad
head (into the roof of the mouth, really1), but there is also a thin
transparent nictitating membrane that rises, and so helps in the
process. (See Fig. 274.)
There are two straight narrow ridges or crests passing back-
ward between the eyes from above the nostrils to a point behind
the eyes. Here each crest turns a sharp angle (very nearly a
right angle) and passes downward back of the eye to a flat, brown
spot posterior to and somewhat underneath the eye. (Fig. 48.)
These crests are made by the bones of the crown of the head.
The flat vertical oval (Colour Plate III) is the external
evidence of the ear. There is no external ear, and this spot is the
tympanum or drum of the ear, which is at the surface of the
body, protected only by the skin which covers it.
The hand has four fingers. The foot has five toes connected
by short thick webs. A short black spur (inner sole tubercle),
which is strong and horny, extends downward from the inner mar-
gin of the foot just back of the first toe. There is a smaller tuber-
cle opposite this, on the sole of the foot. (See Fig. 44.)
The entire dorsal surface is rough with rounded wart-like
elevations of various sizes. Two very large elongated ones (paro-
toid glands) are situated just behind the eyes. (See Figs. 47
and 48.)
If we examine many toads during the summer, we find that
the colour is usually dull brown, with or without lighter markings
forming patches and bands. There is usually a line of lighter
shade down the middle of the back. Very often the ground colour
is yellowish brown, perhaps darker at the head. The smaller,
wart-like elevations may be tipped with red. Those above the
ear are often of a bright orange hue. Sometimes there are four
larger elevations, or spots of colour, arranged along each side of
" Sweet are the uses of adversity,
Which like the toad, ugly and venomous,
Wears yet a precious jewel in his head." — Shakespeare.
" The ungainly toad
That crawls from his secure abode,
Within the mossy garden wall,
When evening dews begin to fall.
Oh, mark the beauty of his eye,
What wonders in that circle lie!
So clear, so bright, our fathers said —
' He wears a jewel in his head.' " — Shakespeare.
i See Bullfrog, pp 231,233.
77
Bufonidse
the white line in the middle of the back. These may be bright
red-brown conspicuously bordered with black, the black in its turn
being ringed with yellow, and may thus give the effect of yellow-
rimmed eyes. The two large swellings (parotoid glands) behind
the eyes may have the same colour as the background, or they
may differ, being yellow or red-brown when the toad is dull brown,
or dull brown when the skin as a whole is yellow or red in tone.
The female is larger than the male, and is usually lighter and
more variegated in colour. In both sexes the granular under-
surface is light, sometimes tinged with yellow, red, or brown, and
having either few or many dark spots. (See Fig. 62.) The adult
male has a blackish throat.
At the close of a hot summer's day we sit on the doorstep of a
country house, delighting in the coolness and repose, and watching
the lengthening shadows of grape-trellis, well-curb, and house. A
fat toad comes out from under the doorstep, where he has been
quietly sleeping all day; another, clean and bright-eyed, comes
from under the sidewalk at our feet. They start off with leisurely
hops toward the garden to search for caterpillars and other deli-
cious morsels of a toad's menu. We watch their retreating backs
(Fig. 47) until they disappear among rows of beets and lettuce,
and we wish them " good hunting." Night after night, summer
after summer, toads come out in search of food. They become a
part of the place. They help to make the home and contribute
their share in its work.
Toads choose cool, moist places in which to live. They are
often found in cellars, under porches and sidewalks, and in various
dark or damp hiding-places.1 They seek such locations not only
for the shelter, but also for the moisture. A toad never has the
pleasure of drinking water in the usual way. All the water that
he gets is absorbed through his skin. A toad kept in a dry place
grows thinner and more distressed-looking, and is likely to die
within a few days; whereas one provided with plenty of moisture
remains plump and contented as the weeks go by, even when there
is a scarcity of food.
It would, however, be a great mistake to think that a toad
does not take pleasure in drinking. He sprawls out in shallow
water or on a wet surface and has a contented expression in his
1 From this fact probably originated the epithet " loathsome," in connection with the toad.
78
THE FROG BOOK
PLATE XVII
FIG. 47.— We watch their retreating- backs. [Male toad at the left ; female at the right.]
FIG. 48.— The AMERICAN TOAD. Photographed to show the narrow bony crest of the head.
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The American Toad
wonderful eyes as he literally " soaks in " the water. In the
country in midsummer, when pools and springs are dry, toads
very often travel long distances to spend the night on the wet
ground about a well of some sort.1
In their search for moisture, they sometimes unwittingly
fall into wells to lead a most sombre existence, feeding upon the
few low forms of life that live there and upon unfortunates who
become prisoners in the same way that they themselves did.
Release may come if the well has a bucket, but more likely their
fate is a tragic one. Their crushed bodies have been taken from
pumps into which they have been sucked. They have sometimes
been found hibernating in old wells, where they must have been for
ten or fifteen years, judging by the amount of debris under which
they are buried.2
We always have been, and still are, somewhat prejudiced
against the coldness of the toad. He is less fortunate than we
are, in being wholly, instead of only partially, dependent on the
sun for his warmth. On a warm day his temperature may be
very high and on a cold day he is very cold indeed,3 so cold that
he may snuggle deeper into his bed and sleep all day. Our epithet
" slimy " he does not deserve at all. In fact, he is quite dry
and comfortable to the touch, at least he is so when we first
take him up. A moment later — if we seized him too quickly
and vigorously — he may be somewhat wet; for among his pro-
tective habits is the one of pouring out a colourless, odourless fluid
upon the enemy. But even with this he is quite harmless.4
In addition to this fluid, the toad has another, which is slightly
poisonous, and which is secreted by the skin. This secretion is
especially abundant in the parotoid glands, the two large swellings
behind the eyes. When the toad is in very great agony — as, for
example, when he is seized by the teeth of an enemy — he pours
out this fluid in sufficient quantity to cause it to appear in milky
drops on the gland-like swellings. This fluid has a disagreeable
effect on the mucous membrane of the mouth, and so protects the
1 Wild Life near Home, By Dallas Lore Sharp.
2 J. A. Allen. Amphibia Found in the Vicinity of Springfield, Mass. Proc. Bost. Soc. Nat.
Hist., XII, 1865.
3 Cold-blooded vertebrates have a variable temperature, dependent on the temperature of
surroundings.
* The toad can in no possible way produce warts.
79
Bufonidse
toad from many enemies. Watch the dog's behaviour towards
toads that have taken up their residence in the garden or about the
house. He either gives them a wide berth or simply teases them,
being careful not to take them into his mouth. A young dog
may bite a toad, but the experience is likely to prove so disagreeable
that he does not repeat it. The irritating secretion is not poured
out at all unless the toad is in severe pain. This fluid can do no
injury to man, unless it gets into the mouth or eyes.1
The toad has been greatly maligned by stories of its poisonous
effects on man and man's belongings. Instead of bringing ill luck,
the gentle fellow is one of our great blessings. The toad has come
to our gardens and to the very doors of our houses because he can
get an abundance of food there; also, because as one of man's
domestic animals, he escapes some of his natural enemies. As for
man, he may well look upon the toad at his door as a good fairy —
somewhat in disguise, we must admit. In fact, we might let the
toad remain wrapped in the veil of magic that the superstition of
past ages put upon him, but change the import of the magic to
good instead of evil.
That the toad is the gardener's ally has been proved beyond
a doubt.2 The economic value of the toad has been recognised in
this country as well as in others. For many years, gardeners in
France have been glad to buy toads in order to have them as
insect-destroyers.
The toad remains quietly sleeping through the greater part of
the day, thereby keeping himself from being a nuisance and also
saving himself from the danger of being stepped upon. But at
sunset, or often earlier than that, he comes out from his bed under
porch or shrubbery and starts on his regular tour over lawns and
through gardens.
The hunt is an exciting one, for the toad eats living, moving
1 I have seen it naturally exuded but once in the several years of my observation of the
American toad. This secretion has no power to produce warts. See p. 16.
2 We are just finding out how many allies man has in his work of tilling the soil. We know
now that birds of many sorts are of infinite value. Rose-breasted grosbeaks will keep a field cleaned
of " potato-bugs." Kingbirds eat so many grasshoppers that they save a large share of the hay har-
vest. Bob-whites and even crows are of great value in destroying cutworms.
And humbler even than these, the insects cross-pollinate flowers, making possible fruits of all
kinds and seeds for new crops and new varieties of economic plants.
The earthworms actually plough the ground, slowly but certainly converting sterile into fertile
land. Even the bacteria of the soil can be used by man to increase his crops greatly. (" Bacteria
and the Nitrogen Problem." Geo. T. Moore. Reprint from Yearbook of Department of Agri-
culture for 1902.) The farmer need not work alone; he has at his command a whole army of helpers.
80
The American Toad
food only. He must " lie low," approach cautiously but rapidly,
move most alertly at the final moment, and perhaps meet with
disappointment after all, as the grasshopper takes wing or the
caterpillar rolls into a motionless ball. Then there is always the
possibility of a lurking enemy. It may be a snake that lives under
the wood-pile and is out on his afternoon hunt, or an owl that
nests in the hollow oak and in the dusk approaches so silently that
the first intimation of her nearness is the clutch of sharp claws.
Or a skunk may roll the toad under his paw, preliminary to swal-
lowing it.
The chase must always be an
eager one, because the toad is
always hungry. His gastronomic
ability is so great that he must
have four meals per day, or rather
his stomach must be filled and
emptied four times in each twenty-four
hours. He must therefore hunt and eat
almost incessantly in order to get as
much as he needs.
The tongue of the toad, with which
he catches his food, is admirably adapted
to it swork. It has a sticky surface, from
which escape of the prey is impossible,
and it is fastened at the front instead
of at the back. The latter fact makes it
possible for the toad to throw the tongue
well out of the mouth. (Fig. 49.)
The toad eats almost all kinds of
small living things that are out in the
late afternoon and at night. He may
sit for an hour or more on the back step
and catch the flies and mosquitoes that
come to the screen-door in their attempt
to get into the house. He sits with head
bent forward and eyes looking very
bright and intelligent. When he sees
a fly alight within two inches of his
nose, he makes no perceptible move-
ment of the head or body.
81
Fig. 49. To show the
movement of the toad's
tongue in catching an insect.
The tongue is fastened in
front instead of at the back
and can be extended fully
two inches, in an exceed-
ingly rapid movement. Its
surface is sticky.
Bufonidas
The toad eats the black crickets1 that are
said to damage the strawberry crop.
The mouth opens and
the fly is gone. When the
fly alights farther away,
the toad springs forward
on his strong hind legs,
then easily slips back into
a sitting posture again.
That is all that we can see,
but again the fly is gone.
Look once more.
There are many chances to
observe, for he is bobbing
back and forth as fast as possible, and the flies are constantly
disappearing. The free hind end of the tongue is thrown out
and pulled back so quickly that we can scarcely see the flash
of pink. The tongue touches the fly, however, which adheres
to its sticky surface, and so is carried far into the back of
the mouth.
The toad walks over the lawn and catches the crickets, the
locusts, and the grasshoppers there, not in the least objecting to
their hard coats, their long spiny legs, and the " molasses " of the
locusts. (Figs. 50 and 51.) He may swallow even a bee or a wasp
found on the low clovers or dandelions, and seems to feel much less
uncomfortable afterward than one might suppose.
Farther out in the garden, he snaps up the beetles and bugs
that are running close to the ground or eating the potato, squash
or cucumber leaves.
He rejoices as a blundering May beetle noisily sheathes its
wings near him. (Fig. 53.) Before it has time to begin the task
of laying its many
eggs, it furnishes a
mouthful that makes
the toad shut his
eyes hard several
times to get the big
thing swallowed.
For, strange as it
may seem, the large
eyes of the toad can
The wingless grasshopper (Cciitlwphilus) of the
ground.
1 Gryllus abbreviates.
82
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The Southern Toad
We also find the toad's song one of the most beautiful sounds
in nature. The effect of a " chorus " of toads is most harmonious
indeed — a crooning sound that seems a fit companion for amorous
spring air, bursting flower buds, and the feeling of new life in our
own hearts.
THE SOUTHERN TOAD
Bufo lentiginosus Shaw
IDENTIFICATION CHARACTERISTICS
Colour: Variable, often bright red-brown, with or without
darker spots, a light vertebral stripe or a broader light band on the
sides. The male may be nearly black. The young toads (one to
three years old) may show much bright orange in the colouration.
(For one phase of colouration, see Colour Plate IV.)
Measurements: Size of Bufo americanus, i.e. male 2^ to 3
inches; female much larger. Head relatively long, its length
contained only 3^ to 4 times in total length. (Fig. 64.)
Structure: Parotoid glands relatively small and narrow. Crests
of the head remarkably conspicuous, because of the elevation,
posteriorly, of the divergent straight crests which lie on top of the
head between the eyes. These are not only greatly elevated, but
also are swollen into large knobs at their ends. Meeting each of
these ridges just in front of the knob and behind the eye is a second
ridge, which extends at right angles to the first downward to a
point above the ear. A third ridge on each side passes backward
from this point to the parotoid gland. (See Figs. 64 to 67, and
compare with Figs. 48, 70, and 84.)
Range: The Southern States east of Texas.
This Southern toad, which is so like the American toad, its
near relative at the North, is a valuable and interesting ally to
man. It is very common, and may be seen in large numbers about
houses and gardens in late afternoon and at dusk. During the
daytime it hides in burrows of its own making, or in moist places
under boards and stones.
It is probably of this toad that the following incident is told.
The story illustrates the rapidity with which food is seized and
89
Bufonidae
swallowed, and the small part played in the process by the sense of
taste. Among its other insect food the Southern toad finds fire-
flies very palatable. So small boys feed the toad with the burning
ends of matches, and it is said that only after several have been
swallowed does the toad find out its mistake and object to the heat.
The male is very much smaller than the female and is much
duskier in colouring. The general colour may vary from light
reddish or greenish brown to black. There is usually a light stripe
along the middle of the back and a broader one lengthwise along
each side. The underparts are dirty white. The upper surface
is warty, but much less strongly so than is the corresponding sur-
face in the American toad. (Compare Figs. 67 and 48.) The
parotoid glands are somewhat kidney-shaped and are relatively
narrow. The eye is unusually large and beautiful, with an elon-
gated black oval pupil and a golden iris. The ear is large (though
smaller than the eye) and is vertically oval.
The foot is smaller and more slender than that of the American
toad, and the foot tubercles are correspondingly smaller. The
mouth has a conspicuous indentation in the upper jaw and a hook-
like extension of the lower jaw to fit into this indentation.
This toad is one o^the meekest and gentlest looking creatures
that ever lived a lowly life on]the ground. (Fig. 65.) Although it
becomes very tame in captivity, so that it will take food from one's
fingers, or eat sitting in the hand, it still remains very timid, and is
startled by any rapid or unexpected movement. (Fig. 66.) While
in captivity, toads of this species ate earthworms and insects of
various sorts. Among the latter were large polyphemus cater-
pillars, hairy caterpillars (such as yellow bear and woolly bear),
various sphinx caterpillars, red-legged locusts, and in fact all
insects offered, except a large staghorn beetle. This beetle was
swallowed, but was almost immediately disgorged, and the toad
showed evident signs of discomfort long after. Bufo lentiginosus,
like many other toads, shows, when excited, curious, nervous move-
ments of the toes. These movements are especially conspicuous
when the toad is watching a moving worm or insect just before
seizing it.
After having been kept in a dry place for a few days, this toad
— as well as Bufo I. woodhousei from Arizona, and other toads
from southern North America — displays an interesting relation
to water and interesting movements in it. When released in
90
COLOR PLATE "iV
The upper figure shows one phase of coloration of the Southern
\BufolentiginosusStew. Female. Mimmsville Gal
The second figure represents the Rocky Mountain Toad \Bufo
1. woodhousei Bd. and Gird. Female. Phoenix, Arizona ]
The remaining two are male and female of Fowler's Toad
\tiufofowleri Putnam. Providence, R. I.]
Refer to Index to locate descriptions.
THE FROG BOOK
COLOR PLATE IV
-
The Rocky Mountain Toad
proximity to water, the toad hops eagerly towards it and squats in
a place where it is shallow. After sitting quietly for a few mo-
ments, he turns around once or twice, then puts the water up on
his eyes and the top of his head by means of his hands, using first
one and then the other. This is not surprising, for we have seen
the front feet used as hands in a similar movement during moulting
or eating. However, there follows a most unusual movement,
showing that the hind legs can be put to uses other than those of
burrowing and locomotion. The wet feet are lifted one at a time,
and their under surfaces are rubbed very dexterously over the
toad's back and sides until all is wet. Finally, the hind legs are
stretched backward and rubbed together in the water in a fashion
that reminds us of the similar movement of the hind legs of a fly.
The throat of the male is black, and expands into a rounded
resonating sac when the toad gives its call. This call consists of(
a single tone, which is vibrated, and which lasts several seconds.
It is high-pitched and extremely sweet; in fact, it would take
a practiced ear to distinguish the call from that of the American
toad.
Bufo lentiginosus and Bufo americanus do not show a series
of intergrading forms in a district intermediate in position to
their respective southern and northern centres of distribution.
Instead, they seem to be distinct species occupying the same lo-
calities where their ranges overlap.
THE ROCK7 MOUNTAIN TOAD
Bufo lentiginosus woodhousei Girard
IDENTIFICATION CHARACTERISTICS
Colour: Usually dingy greyish or yellowish brown, with much
yellow on the lower sides and on the concealed portion of the
femur. The toad may be conspicuously spotted with dark
(Figs. 71 and 73), or unspotted, the rounded warts alone being
dark-coloured. There is a light vertebral streak. Underparts
light yellowish, unspotted, except for aggregations of small black
spots on the breast. (Figs. 69 and 73.) Eye metallic yellow.
Throat of male ;black. Tips of fingers and toes dark-coloured.
(For one phase of colouration, see Colour Plate IV.)
Measurements: Size unusually large, i. e. male 3^ to 4 inches.
Bufonidae
female 4 to 5^ inches. Head short, its length contained in total
length nearly five times. (Fig. 68.) A toad having a length of head
seven-eighths inch has a width if inch. The length of the leg
to the heel equals the length of the body forward to some point
between the eye and the end of the muzzle. Tibia but little longer
than femur. (Fig. 70.)
Structure: Skin rough, with rounded warts. Eyelids warty.
(Fig. 70.) Parotoids long and oval, not reniform in shape and
not descending greatly on the shoulders. Ear a distinct vertical
oval, variable in size from a diameter half that of the eye to one
which in the case of old specimens almost equals it. The top of
the head is usually lifted above the neck region behind. (Figs. 73
and 74.) There are two conspicuous bony ridges parallel be-
tween the eyes. These may have a groove between them, and
may have their edges crenated along this groove (Fig. 70), or
they may be obscured by having the groove quite filled up between
them. (Figs. 72, 73 and 74.) At right angles behind the eyes these
ridges meet two other ridges, each of which extends outward
and downward between the eye and the parotoid to the ear
on its respective side. Muzzle not projecting greatly beyond
the lip. Palm with one large tubercle (Fig. 69), and a smaller
one at the inner base of the first finger. Sole of foot rough,
with small tubercles. Web of foot relatively short. Inner
tubercle usually large, with free cutting edge. Outer tubercle
large, but flat, without cutting edge. (Fig. 71.)
Range: This is the common toad of the Rocky Mountain
region. It is reported from Montana, Nevada, Utah, Colorado,
Nebraska, Kansas, Arizona, New Mexico, and Texas.
The Rocky Mountain toad is usually dingy in colour. Just
after a moult, its colouration becomes brighter and richer in tone,
with sharp contrast between the spots and the background. It
has great power of change of colour from light to dark.
It is related to the American toad (Bufo americanus), and
still more closely to the Southern toad (Bufo lentiginosus), but
attains a greater size than either of these. The male of this toad
is about the size of the female of the American toad. The relative
length of the head and the shape of the cranial crests will always
92
THE FROG BOOK
PLATE XXV
FIG. 68.— The ROCKY MOUNTAIN TOAD. (J?w/b /. woodhousei Gird) Phoenix, Arizona. (For coloration see
Colour Plate IV.) A large rough-skinned toad with an unusually short head.
FIG. (x).—Bufo I. u'oodhousei G\rA. Ft. Worth, Texas. Struc-
ture study of the under parts (in water).
FIG. 70. — Bitfo I. 'icoodhtnisci Gird. Phurnix,
Ariz. Structure study of the bony crests of the
head and of the texture of the skin of the upper
surface.
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suffice to distinguish it from Bufo lentiginosus. However, its
characteristics are so like those of Bufo americanus that in some
specimens it is almost impossible to make the distinction, and it
would then seem that Bufo I. woodhousei is Bufo americanus with
only the variation to be expected from a different geographical
distribution. The three toads mentioned are alike not only in
general appearance, but in each case the male has a wrinkled
black throat, and can extend a rounded vocal throat-pouch. In
each case, also, the call given is a vibrated note of high pitch and
sweet quality. These calls are difficult to distinguish one from
the other, and prove a common ancestor.
This toad is often confused with Bufo cognatus, which is
found in many of the same localities. The confusion arises, how-
ever, on superficial examination only, as the two toads are very
different indeed. The cranial ridges of Bufo cognatus are not
parallel, but diverge backward from a prominent bony elevation
between the nostrils. (See Figs. 70 and 89.) The voices of the two
are different, and could never be confused after once hearing.
That of Bufo woodbousei is sweet and musical, while the other
is emphatically the opposite. The vocal pouch of Bufo wood-
housei is a rounded sac extending from the margin of the lower
jaw to the line on the breast somewhat below the arm insertions
and from one angle of the jaw to the other. That of Bufo cog-
natus is a bladder sent out from the base of the throat in the
midline between the arm insertions. (See Fig. 100.)
There are many minor differences between the two, such as
the following: The foot of Bufo cognatus is relatively much longer
than that of Bufo woodbousei (compare Figs. 70 and 91); the
parotoids of Bufo cognatus extend obliquely down on the
shoulder, while those of Bufo woodbousei are almost parallel.
(See Figs. 68 and 91.)
FOWLER'S TOAD
Bufo fowleri Putnam
IDENTIFICATION CHARACTERISTICS
Colour: General colour light or dark grey (or dull brown), which
may be greenish or yellowish in tone, very rarely reddish. Some-
times dark or dingy and unspotted; more often spotted and
93
Bufonidae
striped with dull brown or black. A prominent light vertebral
streak and spots margined with light. (See Figs. 77, 78, 80, and
84.) Spots'unusually distinct, and seldom deviating from a typical
arrangement. This arrangement is as follows: six pairs along the
vertebral streak — first pair, elongated spots placed obliquely on
the eyelids and top of the head; second pair, rounded and small,
between the anterior ends of the parotoids; third pair, greatly
elongated, more or less pear-shaped, situated on the anterior
part of the back; fourth, fifth, and sixth pairs irregular, the
last often obscure. There is an irregular band of light colour on
the side bounded below by dark. Between the anterior part of
the eye and the jaw there is a dark band, and back of this, ex-
tending from the eye and lower border of the parotoid, there are
three or four dark bands, more or less parallel to this one. The
warts situated on the dark spots are usually lighter or brighter
than the spots. Iris bright metallic yellow, with tracery of
black veining. Throat of male black. Throat of female light,
with perhaps a few spots on the jaw. Underparts light, un-
spotted. (See Figs. 75 and 79.) There may be much yellow
reticulated with black on the posterior .lower sides and on the
anterior and posterior faces of the femur.
Measurements: Size medium, i.e. male 2^ inches, female
slightly larger. Head relatively short; length of head contained
in total length about four times. Legs relatively long, i. e. length
of leg to heel equals length of body forward to some point anterior
to the eye in the female and to the muzzle or beyond in the male.
Tibia longer than femur.
Structure: Skin everywhere finely warty on the upper parts.
Groups of somewhat larger warts on the^dark spots of the back.
(See Fig. 84 and Colour Plate IV.) Underparts granulated. Paro-
toids long, narrow, parallel ovals. (Fig. 84.) The top of the head
may be higher than the neck region behind. The two bony crests
of the top of the head are variable in their characteristics. They
are usually near each other, considerably elevated, parallel, and
grown together at their posterior ends. Conspicuous ridges
behind the eyes meet these parallel ridges at right angles. Ear a
vertical oval, two-thirds the size of the eye. The muzzle projects
beyond the upper lip. The nostrils, which open upward, are sit-
uated half-way between the eye and the jaw on a vertical line with
the upper lip. Fingers slender, prominent tubercles under
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Bufo Cognatus
Judging from the series of decidedly different sizes of this
toad found in the spring, at least five years must be required for
full growth to be attained.
The female Bufo cognatus seldom makes any sound. When
taken in the hand, it shakes with wrath, but usually remains silent.
The male however, "talks" in a voice resembling the squawk of
a toy doll. This squawk of the Bufo cognatus is much like the
sound produced by Bufo halophilus of California. The harsh note
is given over and over again at brief intervals until the cause of
annoyance is removed. The pitch of the note is low, ranging
from B to A ' below middle C. In the midst of the harsh low-
pitched notes, the toad sometimes surprises one by giving a cry
pitched about two octaves above (usually A ).
At the base of the throat of the male is a wrinkled black and
purplish spot, which at first sight, one might judge the result of
an injury. This is thin skin, lying fold upon fold, and can be
extended into a vocal bladder of enormous size. (See Fig. 100.)
Bufo cognatus is not nearly related to the American Toad or to
Bufo lentiginosus, but is closely connected with Bufo compactilis
of the Southwest and Bufo quercicus of Georgia and Florida. The
relationship shows itself not only in various technical details, but
in visible external features. They each show the reduced femur
and short leg, the short head and broad depressed body, diverging
parotoid glands that descend on the shoulders, well-developed
sole tubercles, deeply indented webs, and a vocal bladder at the
base of the throat. The cranial ridges mark a point of variance
among the three. The variation in size also is notable. Bufo
quercicus is the smallest known toad in the world, measuring only
an inch and a quarter in length. Bufo compactilis is medium in
size, and Bufo cognatus is one of the largest toads in North
America.
Bufo cognatus is peculiarly alert and active. When annoyed,
it inflates the lungs, thus greatly increasing the size of the body,
and lowers the head in a defensive attitude. It is incapable,
however, of any defense beyond this, and stealthily creeps away,
keeping the flattened body close to the ground.
A curious incident occurred when Bufo cognatus was being
kept in captivity for study — an incident probably illustrative of
the way in which stories have arisen regarding toads found in
stones and buried in impossible places. A large fat specimen of
IOI
Bufonidae
Bufo 'cognatus escaped one morning from its moss-garden in a
building in Rhode Island. That day repairs had been begun on a
cement floor in the basement of the building. In the afternoon of
the day, while workmen were continuing to remove the cement
floor — which had been put down seven years before — they
came upon a fat toad just fitting a burrow under the floor. Ex-
citement followed, with many stories of toads found in similar
situations where they had been for more than seven years. If
the toad had not turned out to be the lost Bufo cognatus from
Colorado, and had been a native of Rhode Island, there would
have existed no proof that it had not been there seven years
instead of a few hours.
BUFO COMPACTILIS, WIEGM
IDENTIFICATION CHARACTERISTICS
Colour: Greenish-grey or brown, generally light in tone. No
vertebral light streak. Spotted irregularly with dark, or without
spots. Small warts everywhere may be tipped with red. There
may be large dark spots on the lower sides and on the legs and
arms. Hands and feet light-coloured. Large tubercles of the foot
black. Toes tipped with black. Iris yellowish. Underparts
light, unspotted. Throat of male dark. (See Figs. 93 to 95.)
Measurements: Size medium, i. e. length 2^ to 3^ inches.
Head short. Head anterior to eyes rounded and remarkably
short. The legs are short, the femur scarcely showing at all out-
side of the skin of the body. The length of the leg to the heel is
shorter than that of the body forward to the ear.
Structure: Body unusually fat and squat. Whole surface
evenly and closely covered with small rounded warts. These
closely placed warts are also on the top of the head and on the
eyelids. (Fig. 95.) Crown of head flat, without bony ridges
(although there may be slight traces of ridges inside of and behind
the eyes). Ear a small vertical oval. (Fig. 93.) Parotoid
glands are short ovals, extending obliquely outward and down-
ward. (Fig. 95.) Hands and feet small and delicate. One
extremely large tubercle with cutting edge on the palm. Two
sole tubercles, each unusually large and each with cutting edge.
(Fig. 94.) Webs medium in development.
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Bufo Compactilis
Range: Bufo eompactilis is reported from New Mexico, Texas,
and Kansas.
Bufo compactilis bears, at first sight, a striking resemblance to
the burrowing Spadefoot Toads. It is like Scaphiopus bammondii
and Scaphiopus couchii in fact, in the shape and proportions of
body and legs, the size and disposition of the warts, and in the
unusual development of the foot for burrowing. The resemblance
is only superficial, however, as the horizontal pupil tells us at once.
Bufo compactilis is a true toad, closely related to Bufo cognatus.
This toad has strong instincts for hiding and burrowing.
When kept in captivity in moss-gardens with other toads, it is
always found under the moss and leaves, while the others may be
on top. If it does happen to be out in search of food and an
enemy approaches, it flattens and spreads itself on the ground
until it looks like a circular pebbly surface elevated an inch or less.
The young toads, when examined closely, sometimes show a
beautiful colouration. The soft grey-brown of the background is
enlivened by the bright red tips of the warts, and enriched by a
few black spots and many irregularly placed moss-green patches.
The eye is bright and intelligent looking, and indicates the
alertness and activity which make this toad no exception in its
group.
When annoyed, it gives repeatedly a note that has somewhat
the quality of the quack of a duck. But its musical powers do not
stop here, as we would know if we examined the throat region.
There is a wrinkled sac at the middle point of the throat, on a line
with the angles of the jaws. It consists of fold upon fold of thin
skin, confined to a spot of not more than one-half inch in diameter.
These folds are released one after another as the sac is inflated
until there is produced a large blind tube looking like the bladder
of a fish. (Figs. 96 to 98.) The toad may sit very erect while singing,
and the bladder extends forward and upward to a considerable
distance above the head. The call is very loud and penetrating,
and is harsh in quality. The calls are repeated continually, about
one per second, with a short pause between each two. The bladder
remains inflated during the calling but decreases somewhat in
size between the notes. The pitch in the specimens observed was
about two octaves above middle C (D }. Thejiotes were kept
103
Bufonidae
at this pitch for some minutes, when suddenly there would be a
distinct drop, followed almost immediately by a sudden rise again
to the original pitch.
The life history and habits of Bufo compactilis are not on
record.
THE OAK TOAD
Bufo quercicus Holbrook
IDENTIFICATION CHARACTERISTICS
Colour: Rich dark brown or grey -brown, with a distinct white
or yellow vertebral streak extending forward to the margin of the
upper jaw. The warts along this light line may be tipped with vivid
red and orange, as are also those on the posterior part of the eyelid
and on the sides of the body. Four pairs of black spots —
irregular, elongated, white-edged — lie along the vertebral line.
The first spots are on the top of the head. Underparts grayish
white, unspotted. Throat of male dusky. Light band from end
of parotoid gland backward. A broad black band on the side of
the body is made conspicuous by this white above and the white
of the underparts. Bright orange on palms of hands and soles of
feet ; also some orange on under surface of femur. Sole tubercles
black. Legs irregularly spotted or banded with black. (Fig. 101.)
Measurements: Size small, i.e. length of adult ij inches.
Head short, its length contained in total length four times. Legs
extremely short; length to heel not equalling length of body for-
ward to the arm insertion. Femur almost concealed in the skin
of thelbody, tibia not much longer. (Figs. 101 and 106.)
Structure: Exposed surface everywhere thickly set with warts
of varying degrees of minuteness. These warts cover the head
and eyelids, back, sides, legs, and arms. Those on the forearm
and tarsus are spinous. The palms of the hands and soles of the
feet are finely tubercular. Underparts everywhere granulated,
even the throat. (Fig. 106.) The parotoid glands are oval and
long (three times length of eye), extending down on the sides.
(Fig. 103.) The bony crests of the head are parallel and widely
separated. They extend backward close to the inner edges of
the orbits; their ends bend abruptly inward, a little beyond
the anterior ends of the parotoid glands. The ridges back of the
104
THE FROG BOOK
PLATE XXXV
FIG. 101 (i).— The OAK TOAD (Bvfo queicicus Holbrook). Ozona, Florida. Nat. size i# in. Photographed (in
water) to show bony crests of the head, and the arrangement of light and dark colour on the upper parts.
FIGS. 102 to 104 (2-4). — The OAK TOAD is closely covered with small warts which are spinous on legs and arms
FIG. 105 (5). — Rufo que rcicus is a most alert toad.
FIG. 106 (6). — To show structure of the underparts.
THE FROG BOOK
PLATE XXXVI
FIGS. 107 to icy. — linfo ali'iii ius Clirard. Phoenix, Arizona. Photographed to show skin texture, parotoid glands,
cranial crests and other identification points. Actual length 5 in. (For coloration see Colour Plate V.)
The Oak Toad
eyes and those extending backward to the parotoid glands are
well marked. (Fig. 101.) The inner sole tubercle is fairly large,
considering the diminutive size of the foot. The outer tubercle is
small. The webs are very short. (Fig. 106.)
Range: Bufo quercicus has been reported from North Car-
olina, South Carolina, Georgia, and Florida.1
This is said to be the smallest known toad. It is a little,
dusky, hopping creature, which has probably been mistaken many
times for the young of Bufo lentiginosus, the Southern toad. It
is so small that we need a lens in order even to make out many of
the details of its appearance. This is especially true of the crests
of the head. They are obscure not only because of their small
size, but'also because of their dusky colour and the warty condition
of the surrounding surface.
The eye has a shining golden iris. Its expression indicates
much alertness. The ear is round and conspicuous, although it is
much smaller than the eye.
It is said2 that this toad may be seen in all kinds of places
and at all times of day; that it is out during the brighest sun-
shine as well as at dusk and after rains. It was first found in
sandy places, where there were low growths of oak — hence its
name, "Oak Toad."
After heavy rains, Oak Toads resort in large numbers to
shallow pools. They are difficult to see, but give notice of their
presence by an ear-splitting chorus of high-pitched sounds.3 The
individual call is like that of a young chicken in distress, but con-
siderably louder. The male alone gives the call, and while pro-
ducing it seems to have in his mouth a transparent bladder about
the size of a man's thumb. The fact is that this toad has a large
vocal bladder that can be extended from the midline of the lower
throat region. This structure relates it to Bufo compadilis and
Bufo cognatus of the Southwest. (See Figs. 97 and 100.)
1 Beaufort and Kinston, N. C.; Charleston, S. C.; Green Cove>prings, Little Sarasota Bay,
Arlington, Milton, Oakland, Ozona, and Kissimee, Fla.
2 Loennberg. Notes on Reptiles and Batrachians collected in Florida in 1892 and 1893.
Proc. U. S. Nat. Museum, vol. XVII, pp. 317, 339.
3C. B Lungren, collector. Ozona, Fla.
105
Bufonidae
When taken in the hand, the Oak Toad gives a rather musical
chirping sound, like that of a young bird.
BUFO ALVARIUS, GIRARD
IDENTIFICATION CHARACTERISTICS
Colour: Greyish or brownish green, of either light or dark
shade. The sparsely scattered small warts are orange in colour,
sometimes rimmed with dark. Underparts light. (Fig. no.)
The throat and breast of the female are mottled with grey. Iris
light or dark metallic yellow, with a prominent veining of red.
The iris is dark in front of and behind the oval black pupil. Fin-
gers and toes tipped with black or red-brown. (For colouration,
see Colour Plate V.)
Measurements: Size large, i. e. length 5 inches or more. The
head is short. Its length is contained 3^ to 4 times in the total
length. Legs relatively short; the length of the leg to the heel
is not equal to the length of the body forward to the ear. Femur
very short. Tibia somewhat longer than femur. Foot very
little longer than tibia. (Fig. in.)
Structure: Skin leathery and smooth. Head rounded in
front. (Fig. 1 08.) The ear is a very distinct vertical oval. The
bony crests of the head are conspicuous, curved ridges. There is
one on each side, which follows the upper border of the eye and
curves outward and downward to the ear. (Fig. 109.) The
parotoids are long and oval, greatly elevated, and very wide apart
at their posterior ends. (Fig. 109.) They are separated from the
eye by the width of the crest only. Small, flat, rounded warts are
scattered over the whole upper surface. There is a large oval
wart on the femur and a long one -- or a line of shorter ones —
on the tibia (along the margin that is nearest the femur when the
leg is folded) . (Fig. 1 09.) These glands are considerably elevated,
and are very conspicuous. There may be a gland similar to these
on the forearm. There are one or more round or oval white warts
behind the angle of the jaw. (Figs. 107 and 108.) The foot is
thick and has a conspicuous ridge along the inner edge of the
tarsus. Both inner and outer sole tubercles are present. (Fig.
in.) The web is short and thick; it extends to the tips of the
toes, but is deeply indented. There are two very large palm
tubercles. (Fig. 1 10.)
106
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THE FROG BOOK
PLATK XXXV11I
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FIG. 112 (Upper Figure). — Bufo valliceps. Hitchcock, Texas. This species of toad is alert, but less wild than most
North American forms. (For one phase of coloration, see colour Plate V.)
FIG. 113.— Photographed (in water) to show outline of jaw, texture of skin of underparts, and structure of hand.
[Enlarged.]
Bufo Alvarius
Range: Bufo alvarius is reported from southern California
(Fort Yuma) and Arizona (Phoenix).
There would never be any possibility of confusing this toad
with any other. Its green colouration and its smooth skin identify
it at once. It is peculiar, also, in attaining a size greater than that
of any other North American species. In addition to these, the
toad has the following other distinctive characteristics: the con-
spicuous glands on the legs, the peculiar white warts at the angle
of the jaw, the curving crests of the head, and the greatly diverg-
ing parotoid glands.
The parotoid glands, beginning immediately back of the eye,
are so long and descend on the shoulder so much that when they
are only three-fourths of an inch apart at their anterior ends, they
may be separated at their posterior ends by a distance more than
twice as great. The parotoids are about the same width through-
out their length. The elevated shoulder-blades show plainly on
the back between them.
The bony crests of the head are smooth and rounded.
Although not greatly elevated, they are very conspicuous, because
of the smoothness and even colour of the surrounding surface.
The crests extend backward from the nostrils in front, diverge
and encircle the eyes. There is a crest under each eye in front,
and another short one passes forward over the ear, on each side.
The skin between the crests on the top of the head is thin and
adheres to the bone underneath.
The ear is unusually conspicuous. It is placed immediately
back of the eye, under the anterior part of the parotoid gland, and
is surrounded by a prominent ridge. The eye is large and gentle
in its expression. The iris is peculiar in having its metallic yellow
thickly set with a tracery of bright red veins. There are two
curious elevations in the gold of the iris; they are situated in the
midline of the eye at the margin of the iris, immediately above and
immediately below the pupil. The eyelid is smooth, but is thick-
ened, and presents a prominent angle at each extremity.
The upper jaw projects beyond the lower so that the nostrils
are set anterior to the vertical line of the mouth-opening. The
oval nostrils are large; they open upwards and backwards. The
inner finger of the male is thickened at the base, and the brown
107
Bufonidse
inner and upper surfaces of the first and second fingers are hard
and horny.
When it is held in the hand, this toad jerks spasmodically,
and vibrates the whole body, as if about to explode with wrath.
The only sound, however, produced in protest is a gentle
chirping note, less loud and emphatic than that of the American
toad.
Most curious are these large, uncouth creatures, with their
great strength of body, their protective rhinoceros-like skins, and
their greatly contrasting meek appearance and gentle voice and
manner. The question of their survival in contest with other
races is a very interesting one.
Bufo alvarius is said to have habits similar to those of our
most common toads.
BUFO VALLICEPS, WIEGM
IDENTIFICATION CHARACTERISTICS
Colour: Variable; often rich brown, with three broad bands
of cream colour or yellowish grey extending from the head to the
posterior end of the body. The central band is straight; the
others are curved, extending from the eyes backward over the
parotoids, then downward on the sides, following the lateral out-
lines of the body. (Figs. 1 12 and 1 14.) The eye varies between
gold and bright coppery red. Light colour along the jaw and
over the shoulder. (Fig. 112.) There may be a few irregularly
placed black or bright orange spots on the back. Usually, a long
and narrow, yellow-bordered spot transversely placed back of the
eyes between the bony ridges. Legs and arms may be banded or
spotted. Underparts^light or dark, unspotted. (Fig. 113.) (For
possible colouration, see Colour Plate V.)
Measurements: Size large i. e. length 3^ to 5 inches. Head
relatively long; a toad 3^ inches long has a length of head of ij
inches. Legs short; the length of the leg to the heel scarcely
equalling the length of the body forward to the eye. Tibia only
slightly longer than the femur. (Fig. 1 14.) Foot short.
Structure: Skin set closely above and below with small tuber-
cles. (Figs. 113 and 114.) The arms and legs are conspicuously
tubercular. Even the palms and soles are set close with tubercles.
1 08
COLOR PLATE V
To show coloration of four toads of Southwestern North
America.
(1) Bufo punctatus Bd. and Gird. Tucson, Ariz.
(2) Bufo cognatus Say. Phoenix, Ariz.
(3) Bufo valliceps Wiegm. Brownsville, Texas.
(4) Bufo alvarius Girard. Phoenix, Ariz.
Refer to Inde.\~ to locate descriptions.
THE FROG DOOK
COLOR PLATE V
COPYRIGHT, 19u6, BY DOU8LEDAY, PAGE A COMPANY
Bufo Valliceps
(Figs. 1 13 and 115.) No large warts. The light-coloured tuber-
cles behind the angle of the jaw and in a row along the lower
margin of the light lateral band are somewhat longer than the
others. (Fig. 114.) Head rounded, acute in front. (Fig. 113.)
Jaws hard and bony. Upper jaw deeply indented in midline.
An elevated bony ridge usually parallel to the upper jaw extends
from in front of the eye to the angle of the jaw. Ear conspicuous
because of its smoothness; half to two-thirds size of eye. (Fig.
112.) The many bony ridges of the head are much elevated,
thin, and sharp-edged, except the short one extending over the
ear backward to the parotoid. The head ridges are as follows:
A short median one from jaw to nostrils; two starting at the
upper end of this diverge backward to a point just behind the
eyes, there converging slightly to points just within the anterior
ends of the prominences made by the scapulars; one each side
connecting at obtuse angles with the long ridges of the top of
the head and lying close behind the eye; a shorter, thicker ridge
between this ridge and the parotoid of each side. There are also
short ridges in front of the eye and between the eye and the ear.
(See Fig. 1 14.) The parotoids are short, and may be oval or
triangular in shape. The nostrils open upward, are close
together and are placed nearer to the jaw than to the eye. The
shoulder-blades are two curved prominences between the paro-
toids. (Fig. 114.) Hand small; one large and one small palm
tubercle. (Fig. 113.) Foot small ; inner and outer tubercles bo-th
present, but insignificant; webs short. (Fig. 115.)
Range: Bufo valliceps Wiegm is a Mexican toad found com-
monly in Texas. It is reported also from Louisiana.
Bufo valliceps is unusual among North American batrachia
in the appearance of its head. The head is broad and shallow,
and except for the bright eyes, seems wholly made up of high bony
crests separating variously shaped bony concavities.
This toad is variable in colour and has much power to change
colour. It may be black with touches of rich orange and yellow-
brown, so that it looks like a piece of burned wood. With such
colouring, the underparts may be as dark as the upper surface.
Such colouration may change within half an hour to delicate fawn-
colour or dove-grey, with the light bands and spots cream white.
109
Bufonidae
At such a time the underparts are white also. Among the me-
dium shades, changes take place rapidly between greys, warm
browns, and olive-greens. In each case the light colour of the
lengthwise bands harmonizes with the background, so that a pleas-
ing colour effect is produced. Young specimens may have the
throat bright yellow.
The crests of the head are usually black, even when the head
itself is light, but they also may become light in colour on a long
enough exposure to sunshine.
Bujo valliceps is alert and active, but is less wild than most
North American species. It is evidently less used to burrowing —
as we should judge from its foot structure — and so does not
become alarmed when finding itself in a place where there is
nothing under which to hide. When annoyed, it gives high-
pitched, bird-like notes. There is no appearance of a vocal pouch.
BUFO PUNCTATUS, BAIRD AND GIRARD
IDENTIFICATION CHARACTERISTICS
Colour: Greyish or reddish brown. Warts tipped with red,
and sometimes encircled by black at their bases. Underparts
light. Throat of male dusky. Much orange on under surfaces
of hands and feet. (For possible colouration, see Colour Plate V.)
Measurements: Size medium, i.e. length 2 to 3 inches.
Length of head enters total length three and a third to three
and a half times. Legs short, heels widely separated behind,
when toad is in sitting position. Femur largely buried in the
skin of the body. Length of leg to heel equals length of body
forward to ear or sometimes to eye.
Structure: Upper parts (head, eyelids, back, and legs) closely
set with small tubercles. Head broad, flat, not thick through.
Very flat between the eyes, and sharply angled along the canthus
rostralis. No bony ridges on top of head (or slight traces of any).
A short bony ridge between ear and eye. Nostrils terminal.
Eyes set wide apart; eyelids broad, i.e. eye strictly vertical in
position. Parotoid gland considerably elevated, but very short
(not much longer than eye), rounded or somewhat triangular.
Ear distinct, round, half the diameter of the eye. The head is
rough, with small granulations. These granulations are promi-
110
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THE FROG BOOK
PLATE XL
'
FIGS. 116 to 120. — Btifo punctatus Bd. and Gird. Dallas, Texas. Length 2l/z in. (For coloration see Colour Plate VI.
Bufo Punctatus
nent on the end of the muzzle, margin of the upper jaw,
canthus rostralis, eyelid, parotoid gland, and bony ridge be-
tween the eye and ear. Sole tubercles both present and both
small. Tubercles under the joints of the toes scarcely dis-
cernible. Tarsus and foot covered with spine-like tubercles.
Webs short, but toes narrowly margined beyond. Tarsal fold
broad and rounded. (For structure, see Figs. 1 16 to 120.)
Range: Bufo punctatus is reported from Texas, Arizona, and
Lower California. It is found in Texas from as far north as Fort
Concho and as far south as San Antonio. Its range extends
along the boundary line between the United States and Mexico to
the Pacific Ocean and up the Colorado River to the Grand
Canon and beyond. In Lower California it has been reported
from the extremity of the peninsula.
Bufo punctatus is one of our most easily distinguished toads.
It has not the usual fat squat form of the toads, but is more slender,
and is rather delicately moulded, in fact. The hands and feet are
peculiarly small and delicate. The shape of the head and its
granular roughness are very distinctive features. Adult speci-
mens may be so small that they do not exceed Hyla versicolor in
size, or Hyla arenicolor, their companion in the ponds in May.
On the other hand, specimens from Lower California may be
large (3 inches) and may differ not only in size, but also in show-
ing a pattern of spots and stripes. The species is apparently
closely related to Bttfo debilis and Bufo valliceps.
Dr. Stejneger gives the following colour description of speci-
mens collected in 1889 at the bottom of the Grand Canon.1
"Above 'malachite-green/ densely speckled with small dots of
bright vermilion; limbs paler, dotted with vermilion and also
with minute black specks, which likewise occur on the flanks;
region surrounding nostrils black; upper lip and whole under sur-
face bluish white, irregularly speckled with black; posterior part
of belly and underside of thighs dark brownish flesh-colour; soles
dull orange."
In captivity these toads make small burrows in moss or soft
i These specimens are similar to those collected in the region of the Little Colorado River
by Mollhausen.
Ill
Bufonidae
earth, and sit patiently hour after hour with just the bright eyes
showing at the doors of their burrows. When taken in the hand,
the male gives a faint bird-like note. Its dusky throat can extend
into a large rounded vocal pouch. The habits and life history of
Bufo punctatus are not recorded.
BUFO DEBILIS, GIRARD
IDENTIFICATION CHARACTERISTICS
Colour: Ashy brown, with small black tubercles. Eyelids
and parotoids may be crossed by black lines. Legs may be
broadly banded with black; these bands may have their outlines
strongest, so as to give the appearance of narrow black cross-lines.
Underparts and concealed surfaces light, unspotted.
Measurements: Size small, i.e. length ij to 2 inches. Head
short, its length contained in total length of head and body four
times or more. Leg short; its total length just equals the total
length of head and body.
Structure: Skin rough, with small warts and granulations.
Underparts finely granular. Head wide and flat; space between
the eyes greater than width of eyelid. Parotoids divergent and
very large, each extending backward to a point beyond the shoul-
der; their upper margins are nearly straight, their lower obtusely
angled. The foot has webs of medium size; the sole tubercles
are insignificant.
Range: Bufo delilis is reported from the following places in
Texas: Upper Wichita River, Nueces River, Lower Rio Grande,
and the Brazos (Waco).
Bufo debilis is a small burrowing toad with an appearance
and range remarkably like those of Bufo punctatus. It can always
be distinguished from the latter, however, by its smaller size, its
shorter legs, and its unusually large parotoid glands.
112
THE FROG BOOK
PLATE XL1
FIG. I2i.— The CALIFORNIA TOAD (Sufo halophiha Baird. Female. Carmel, Cal.) In bright light the California
Toad becomes clay colour or light olive with a pronounced spotting of black. The large warts set in the spots have brownish
red centres.
FIG. 122. — The CALIFORNIA TOAD just from its burrow, or on a dark day, is dusky with spots on the lower sides
and under-surface only. Photographed to show structural characteristics of head.
THE FROG BOOK
PLATE XLII
tibia.
FIG. 123 ( i ).—Bufo haloplnlits Baird. Carmel, Cal. Male ( in aquarium of water) showing light, spotted underparts.
Fu,. 124 (2).— Male. To show web of foot, and sole tubercles.
FIG. 125 (3).— Female. To show vertebral streak, rounded warts, extremely short legs and glandular elevations of the
Fu.. i-'o (4).— Male. The arm is long and muscular. The leg is relatively longer than that of ihe female.
The California Toad
THE CALIFORNIA TOAD
Bufo Imloplnlus Baird
IDENTIFICATION CHARACTERISTICS
Colour: Dusky and unspotted above, or light and conspicu-
ously spotted (even on hands and feet). (Figs. 121 and 122.)
When light, the colour may be yellow, grey or green, in tone. Eye
bright metallic yellow. There is a vertebral streak. (Fig. 125.)
The larger warts are coloured like the background, have red-brown
centres, and are set in the black spots. Legs spotted or barred.
Toes tipped with brown. Underparts dingy white, spotted with
black. (Fig. 123.) Male may be nearly black on the underparts.
Measurements: Size large, i.e. length 4 to 5 inches; female
larger than male. Head relatively short, about quarter the total
length. Legs short, those of the female shorter relatively than
those of the male. The femur scarcely shows outside the skin of
the body. Length of leg to heel equals length of body forward
to the ear. Fingers do not vary greatly in length. Fifth toe
slightly shorter than third.
Structure: Skin with scattered low rounded warts of medium
or large size, skin smooth and shining between the warts. Warts
distributed everywhere, on legs and feet, on head and eyelids.
Large glandular elevations on the tibia. (Fig. 125.) Outline of
jaw rounded. (Fig. 123.) Length of head in front of eye not
greater than the long diameter of the eye. Descent of muzzle
steep in front and under eye. Upper jaw indented in the midline.
Muzzle projects slightly beyond the jaw. Nostrils on a vertical
line with the jaw. No bony crests on the head. Space between
the eyes greater than the width of the eyelid. Eye large. Ear
round, small (one-third to one-half diameter of eye.) Arms of
male very muscular. Palm with one large and one smaller tubercle;
also closely set with many small tubercles. The tubercles under
some of the finger-joints are prominent, i. e., first and second fin-
gers have one each, third and fourth, two each. First, second
and third fingers of male black and horny on their inner margins.
Foot thick and broad; tarsal fold from heel to base of inner toe.
Toes broadly webbed, webs variable in their amount of indenta-
tion. Both outer and inner sole tubercles large.
Range; Type locality, Benicia, California. Reported from San
Bufonidae
Francisco, southern California, and Lower California. It has
been found east of the Sierras also.
Bufo halophilus is a very large, tame-looking toad. On
dark, cool days, it is so dark a dull grey or olive that the spots
are wholly obliterated — only the low rounded warts show. The
colour below becomes dark to correspond with that above. The
parotoids and the glands on the tibia are more distinct in this dark
phase of colouration than in the light. On bright warm days the
toad is a very different-looking creature. It is clay-colour or
light yellowish green, with a pronounced spotting of black or dark
brown, and the warts are brownish-red centred.
When hunting its insect food, this toad often walks instead of
hopping. We should expect this habit, because of the unwieldy
size of the body and the shortness of the legs. When frightened
and trying to escape an enemy, it flattens its body and creeps
along stealthily and alertly. In fact, of all the strong, alert
toads of North America, this is perhaps the strongest and most
alert. Nothing seems to exhaust or cool its ardour, not even
physical injury, if it once becomes alarmed and tries to escape.
When this toad is active and excited, its skin constantly sends
out a secretion, so that it looks and feels slimy. This secretion
has a peculiar oily odour, not especially disagreeable.
It is much dependent on being under the protection of some
cover, even in high temperatures. It makes a shallow burrow for
the day and a deeper one for the winter months.
After having been deprived of water for some time, this toad
shows interesting movements, aimed at getting all parts of the
absorbing skin wet. He squats in shallow water, flattening the
body as much as possible. He moves about slowly, keeping the
body depressed, then puts the water on the top of his head by
means of his hands, and wets his back with his feet. These
movements are always unexpected and interesting.
The female is apparently voiceless; the male gives rapidly
a series of high-pitched notes, like the harsh sounds produced by
a squawking toy doll.
Bufo halophilus has a subspecies representing it at the north;
namely, Bufo halophilus columbiensis (Bufo microscaphus Cope)
with the Columbia River the type locality.
114
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The Common Leopard Frog
If we now look at the embryo from above or below, the
region of head and neck shows slight projections. (Fig. 209.)
Examining these very carefully from the side, we see the appear-
ance shown in Fig. 208. That portion in the most anterior
and largest projection or swelling (sense plate), will become
the facial part of the head, with upper and lower jaws, mouth,
and nostrils. The three smaller elevated portions back of this
are destined to make the gills. There is a blunt projection on
the lower portion of the head end, which, on account of its posi-
tion (the front margin of the sense plate), might be mistaken
for a mouth. Viewed from the front (Fig. 209), it becomes
one side of a horseshoe-shaped structure which will make, not
the mouth, but a pair of " suckers," to be used by the tadpole
to attach itself to water-weeds.
On the sixth day (April I4th) the young tadpoles are still
longer and are more curved in the egg. The body seems much
thinner. The head and tail ends are unmistakable, even to
the casual observer. The projections on the sides of the neck
are more distinct.
On the seventh day the tail is longer and distinctly finned
at its edges. The head is more distinct from the body. The
projections at the sides of the neck are longer. The tadpoles
occasionally move in the egg, putting the head and the tail to-
gether and then jerking them apart. They seem little changed
on the following day but move more often.
On the next morning (April lyth), nine days after the eggs
were laid, we find most of the tadpoles out of the jelly, clinging
by two conspicuous " suckers " to the deserted jelly-mass or
to water-weeds. (Fig. 210.) These "suckers" are not what
their name would seem to imply. They do their work of cling-
ing, not by suction, but by means of a sticky substance or cement
which they secrete. The jelly is much less stiff. Other tad-
poles hatch as we watch : a vigorous wriggle, and the jelly sphere
is ruptured and the tadpole becomes free. The tiny bit of life
may lie flat on the jelly or at the bottom. But after a short
time it is rested from the exertion and wiggles through the water
aimlessly until it touches something that will act as a support.
The tadpole is now about 7f mm. long, very slender and black.
The transparent tail fin is conspicuous. The projections at
the sides of the neck are easily seen as branched finger-like gills
179
Ranidae
that have grown out from the gill plates formed five days ago.
If we examine the tadpole carefully with a lens, not only can
gills and suckers be seen, but prominences that are to become the
eyes (Fig. 210, side view), and an opening just forward of
the suckers that is to be the mouth (Fig. 210, front view).
The low power of the compound microscope used now to
examine the outside of the tadpole shows us many wonderful
things. The blood is flowing in the gills. The current is easily
traced out to the end of each finger-like extension and back again.
The movement is in jerks or pulses, which are ryhthmic, corre-
sponding to the pumping action of the heart. If we look still
more closely, the current is seen to consist of minute circular
bodies (blood corpuscles) that chase each other in most irregular
fashion in a colourless liquid (blood plasma).
However, as we look at the blood movement, another motion
catches our attention. There is a general wave-like motion of
the water over the body of the tadpole in the direction of the tail.
Careful examination reveals the presence of a coat of minute hairs
(cilia) that are in continual motion, and so create this movement
of the water. Cilia appear along the back of the embryo at the
time of the formation of the nerve tube. They increase in
number as development goes on, until the whole body is covered
with them and strong currents of water constantly wash the sur-
face of the tadpole from the head backwards. The most rapid
streams flow over the back and in the region of the gills. This
movement of the cilia, with the resulting circulation of water,
aids the young tadpole in the process of respiration before the
gills are formed. After the gills are well developed, the cilia are
reduced in number so that they do not cover the whole body;
they now serve mainly to bring fresh currents of water to the
gills.
On the tenth day all the tadpoles are out of the eggs. They
hang quietly from water-weed or other support, or circle about
with vigorous wigglings of the tail whenever they are disturbed.
The head becomes larger. This is due to backward growing
folds on the side of the head. It is easy to see that the folds have
progressed quite to the roots of the gills. (Fig. 211, April i8th.)
On the eleventh day they have grown still farther back and have
united underneath the throat. The tadpole is now 9 mm. long,
the increase in length being mainly confined to the tail. On the
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The Common Leopard Frog
twelfth day the gills are entirely covered, except the very tip ends
of two or three branches on the left side. (Fig. 211, April 2oth.)
For two or three days from this time there is little visible
change. The tadpoles (as black as toad tadpoles at the same
age) remain clinging to convenient supports by the suckers, now
greatly reduced in size. They sometimes start out on aimless
circling trips, but, on the whole, are not very active. The body
is now increasing greatly in diameter. This increase in diameter
is due partly to the development of special organs within. Through
the skin of the under side of the body can be seen the intestine,
spirally coiled like a watch-spring. This increase is due also to
the fold which covered the gills growing much farther back on
the body. Here it has united with the body wall on sides and
front, except for a small space on the left, where the tips of the
gills were last visible. It remains unattached at this point all
during the tadpole life. Thus is formed a spout for the exit of
water (Fig. 21 1, April 24th) from the internal gills, which replace
the external gills that we saw covered.1
When we look at the tadpoles on the morning of April 24th
(sixteen days after the eggs were laid), we realize that the mouths
are open. Hungry tadpoles are swimming rapidly, instead of
aimlessly as before, and are nibbling the delicate ends of water-
weeds or vigorously scraping the green slime from the stones and
sticks at the bottom.2 They are no longer jet-black, but are
made to look dark brown because of a fine mottling of gold spots
on the black.
Their life for the next few weeks seems to have only four
needs: to swim rapidly, to eat almost constantly, to rest a little
sometimes, and to grow. Their enemies are many, and their ranks
are greatly thinned by them. It will be fortunate if they escape
the monstrous sucking jaws of the water-tiger.3 They glide up
to nibble the end of a green stem, and the stem comes to life and
sends out a powerful arm equipped with jaws that hold as in a
vice, while smaller jaws4 rapidly eat every part of the tadpole, ex-
cept, perhaps, the long coiled intestine. An unsuspecting tadpole
1 See Bullfrog, p. 236.
2 The mouth structure of the Leopard Frog tadpole corresponds with that of the Bullfrog tad-
pole. (See footnote, p. 235.)
3 The water-tigers are larvas of the diving-beetles (Dytistidse).
* The larva of a dragon-fly (Libellulidz),
181
Ranidse
approaches an inoffensive-looking brown stem, only to find it a
house from which the owner1 rushes with legs that grasp tightly
and jaws
that bite.
The curi-
,ous back-
swimmer2
pounces upon
them and sucks
their blood.
There is small
chance of es-
cape from the
jaws of the div-
ing-beetle,3 or
from the suck-
ing beak of the
giant water-
bug.4 The un-
dulating leech
gets a deadly
A narrow escape from the jaws of the j^
water-tiger
hold upon them while they rest. They are eaten by fish and
turtles, by water-birds, and by their own kin.
What are apparently green stems come to life and send out powerful arms to
capture the tadpoles.
1 Caddis- worm, larva of a caddis-fly (Phryganeidae) . 2 Notonecta. 3 Dytiscus. * Belostoma.
182
The Common Leopard Frog
In early May, those that have lived through all these dangers
are more than an inch long. The tail with its broad transparent
fin is nearly twice as long as the rest of the creature. Soon the
hind legs bud out and develop; the front legs appear; the mouth
and eyes are transformed into those of a frog; the tail is absorbed.
In July and August the marshy borders of the lakes and ponds
in which the Leopard Frogs breed are swarming with small
The back-swimmer is a powerful enemy of young tadpoles.
frogs. (Fig. 199.) Their home is in the shallow water among
water-lilies and pickerel-weeds, or farther in, where sedges, grasses,
and willows grow. They wander over the sand of miniature
beaches or over the adjacent grassy places, in search of the small
insect life they feed upon. Let any disturbance come and they
rush for the water — three or four enormous low leaps, one after
the other, and they disappear under the water with a splash so
slight as scarcely to ruffle the surface enough to show where they
are. We may look with great care, but we cannot find them.
They hide at the roots of grasses or in the water-weeds, keeping
under cover until we are tired and give up the search.
183
Ranidae
We can find many of them
in wet meadows and in the long grass
about wells, much farther from the
water. They are active hunters,
greedily eating spiders, beetles,
crickets, grasshoppers, and other
small creatures of the ground. Feed
one of them with the young grass-
hoppers1 that are so thick in the
clover and grasses. He swallows
them one after another — in fact,
just as rapidly as he can dispose
of the long spiny legs, which still
stick out of his mouth after the
body of the grasshopper is well
swallowed. He will succeed in eat-
ing eight or more in a very few min-
utes, the look of satisfaction in his
eyes increasing as his sides grow
plumper.
Young Leopard Frogs are " aris-
tocratic-looking." They seem espec-
ially long-nosed and slender. They
show the greatest variety in tdress.
The lateral folds are rich yellow or
bronze, as is also the line from the
end of the muzzle to the shoulder.
The spots are darkest at the edges,
and are sometimes not yellow-rimmed as they are in the adults.
Some are brown or tan in colour; others are green. And,
strangest of all, a few of them have no spots at all. (Fig. 199.)
Of these, some are metallic green on head, back, and legs,
with sides strongly marked by golden longitudinal folds,
but with no spot anywhere. Others are plain brown in colour,
almost metallic enough to be called bronze, and have the same
yellow lateral folds. These are more beautiful than the spotted
ones. Some that have plain colour on head and body show ir-
regular spots on the legs and arms.2
1 Acrididae, or short-homed grasshoppers.
2 Much search has not revealed adults in this dress.
184
Late March. The Leopard
Frogs are croaking in the pond
when the blue-birds are decid-
ing on a home.
The Common Leopard Frog
The boys who catch the young
frogs to sell as bait to fishermen call
the plain ones "policemen," the plain
but brilliant colour and the metallic
stripes giving, perhaps, the appear-
ance of a uniform.
The young Leopard Frogs are
sacrificed in hundreds and thousands
as bait, wherever bass and pickerel
fishing is carried on. Each boat-
man about the small lakes of the
Middle West keeps a great wooden
box containing hundreds of the little
frogs, who desperately jump or climb,
only to fall back captives. Boys
search the lake margins, the marshes,
and the meadows, and put their
captives into bags or pails. They
are paid perhaps five cents per dozen
for them. When the frogs become
more scarce, the price may be as high
as twenty-five cents per dozen.
In the meantime the country
about is overrun with grasshoppers
to such an extent that it is difficult
to grow even morning-glory vines
about the houses. Nature's supply
should not be so overwhelmingly
drawn upon, but, as in all similar
cases, the creature for which the
demand is so great should be bred
for the purpose. (See foot note p.
234-)
July. The Leopard Frogs eat
the young grasshoppers that are
so thick in the grass.
Ranlidae
THE SOUTHERN LEOPARD FROG
Rana splenoceplala Cope l
IDENTIFICATION CHARACTERISTICS
Colour: Green or brown, but more often a combination of
the two, with one colour abruptly invading the other in irregular
fashion. (See Colour Plate XII.) Sometimes grey or fawn colour.
Green or brown spots (small, irregular, or rounded), arranged in
two irregular rows between the lateral folds, and still more irregu-
larly on the sides. Spots usually not surrounded by light rings.
Lateral folds light green, golden, or bronze. This colour of
the lateral folds continues forward over the eye and along the
canthus rostralis to the end of the muzzle. Also light metallic
lines along the jaw from the shoulder to the end of the muzzle.
These four converging colour lines meet in acute angles at the
end of the muzzle. Eye golden or bronze, with a dark line through
it. Ear bronze, with a white circular spot at its centre (not an
irregular blotch, such as may be present in Rana pipiens. (Fig.
215.) Upper and lower lips dark, conspicuously spotted with
white. Legs barred or spotted. (These bands or spots may
be edged with light.) (Fig. 214.) Arms conspicuously spotted.
Usually a dark band on the front of the humerus; also on
the front of the femur (Figs. 21 5 and 220.) Concealed part
of femur dark in colour, with yellow or white spots or reticu-
lations. Underparts glistening white, yellow posteriorly. The
throat and breast may be distinctly or obscurely mottled with
brown. Whole frog iridescent. ,
Measurements: Size medium, i.e. 2j to 3^ inches. Head
long, its length contained two and a half times in the total length
of head and body. (Figs. 219 and 220.) Leg long, its length
to the heel exceeding the length of the body forward to the end of
the muzzle. (Fig. 213.) Tibia much longer than femur.
Structure: Skin relatively smooth, very finely tubercular on
back, sides, and tibiae. Tibia may be ridged lengthwise. More
or less unbroken lengthwise folds of skin — four in number —
between the prominent lateral folds. (Figs. 214 and 220.)
Glandular fold along jaw to shoulder. Head narrow, pointed.
iRana wescens sphenocephala Cope.
186
COLOR PLATE XII
To show the coloration of some spotted frogs of North America.
Figs, i and 2.— THE COMMON LEOPARD FROG[V?a»a
pipiens Shreber, Rhode Island]. Typical pattern of color-
ation and great divergence from it.
Figs. 3 and 4.— THE SOUTHERN LEOPARD FROG
[Rana sphenocephala Cope. Immature. Seven Oaks,
Florida.]
Fig. 5. — Immature Rana pipiens. Helotes, Texas.
Fig. 6. — Rana pipiens. Ithaca, New York.
Fig. 7. — Female Rana sphenocephala. Hitchcock, Texas.
Refer to Index to locate descriptions.
THE FROG BOOK
COLOR PLATK XII
COPYRIGHT, 1906, BY DOUBLEDAY, PAGE & COMPANY
THE FPPG BOOK
PLATE LXIX
FIGS 213 and 214.— The SOUTHERN LEOPARD FROG (Kana sphenocephala Cope). The frog at the left is from
Hitchcock. Texas ; the right from Ozona, Florida. Metallic green, brown or fawn color. A most beautiful frog in life, and
extremely active.
FIGS 215 and 216. — Raiia sphenocephala from Seven Oaks, Florida, at the left Rana pi/iicus from Providence, Rhode
island at the right. Note the relative lengths of head and body. Rana sphenocephala always shows a white circular spot
a tint centrt 01 the ear.
THE FROG BOOK-
PLATE LXX
*
FIGS. 217 and 218.— The COMMON LEOPARD FROG (Rana pipiens Shrcber) Denver, Colo. Tl;e head is more or
less pointed. Its length is one-third the total length. There may be a light blotch at the centre of the ear, and a dark spot
fin the head in front of the eyes.
-The SOI 1 IIHRN LEOPARD FROG (Rana sphenocephala Cope). The frog at the left is from
Ozona, Florida ; the right from Hitchcock, Texas. The head is long, narrow and pointed. The length is contained in the
The ear has a circular white spot at its centre. The eyes are large. There is no spot on the head in
il of the eves.
The Southern Leopard Frog
Eyes large; space between them narrow. (Fig. 219.) Nostrils
round, below the line of the prominent canthus rostralis, much
nearer to the end of the muzzle than to the eye. Ear smaller
than eye. Feet long, webs deeply indented. Fingers and toes
long and slender. A tarsal ridge, and outer and inner sole tu-
bercles are present. Thumb of male thickened at base.
Range: Rana splenocephala is common in the Austroriparian
subregion. It is reported from Georgia (Nashville, Saint Si-
mon's Island, Liberty County), Florida (Georgiana, Ozona, Fort
Myers, Seven Oaks), Louisiana (Prairie mer Rouge, New Orleans),
and Texas (Hitchcock). One specimen is reported also from
Wheatland, in southern Indiana.
The Southern Leopard Frog is perhaps the most beautiful
frog in North America. It has not the delicate modest beauty
of the Wood Frog, but it has distinction of form, richness of
colouring, and intricacy of colour pattern. It has not, like the
Wood Frog, an expression indicating gentleness and tameness.
Instead, a creature extremely alert and wild, possessing great
powers of activity, is seen in the unusually large eyes and in the
attentive pose of the slender body. (Fig 215.)
The head is long and pointed, with the eyes set far back.
This characteristic and the unusual length of the hind legs dis-
tinguish the frog at once from Rana pipiens, the Common Leopard
Frog. It is peculiar, also, in possessing a circular white spot at
the centre of the ear. This spot is never lacking, no matter
what the colouration of the frog may be at the time. (Figs.
213, 215, 219, and 220.) Rana pipiens has sometimes a light
blotch at or near the centre of the ear, but never this clean-cut
circle of white.
The background of colouration varies greatly, but is seldom
plain green or brown. Instead, it is a mixture of the two. The
colours are equally intense, and meet each other in irregular lines,
without any blending. The brown is usually a warm shade,
not grey or ashy, and the green is most often pure green, with-
out an unusual amount of either yellow or blue in it. An occa-
sional frog is found which is light yellow-green. The spots may
be dark green or brown, and are not margined with light colour,
187
Ranidse
except on the legs. The spots are irregular in shape and arrange-
ment. Not only do the two sides of the frogs differ in the num-
ber, size and arrangement of the spots, but, what is more unusual,
the two legs are sometimes totally different in these respects.
(Fig. 219.) The colouring is everywhere highly metallic in
character. The changes are not especially rapid. This species
of frog in Texas is often beautiful in a dress of light dove-grey or
fawn-colour. (See Colour Plate XII )
The male Rana spbenocepbala has large vocal pouches, one
at each side, above the arm. These frogs are wild and active.
They leap long distances, and are difficult to catch. The species
is evidently a very distinct one, not intergrading with Rana
pipiens, but holding its own with the latter frog in the same
localities in the southern part of the United States.
THE PICKEREL FROG
Rana palustris Le Conte
IDENTIFICATION CHARACTERISTICS
Colour: Brown, with two more or less regular rows of con-
spicuous squarish spots between the lateral folds, and two irregu-
lar rows of smaller spots on each side below the folds. Legs
barred or irregularly spotted. A conspicuous light line from
muzzle to shoulder. The upper jaw is yellowish, marked with
brown; the lower is white, marked with brown. The under-
parts are white in front, bright orange-yellow posteriorly. The
yellow may extend forward along the sides and outward under
the arms. (For colouration, see Colour Plate XIII.)
Measurements: Size medium; male, 2 to 2^ inches; female,
3 to 3^ inches. The legs are long, the distance from thigh to
heel equalling the combined lengths of head and body. The
ear is smaller than the eye.
Structure: Two relatively broad, non-elevated folds of skin
extending from the eyes backward — the lateral folds. There
are four folds of skin on the back between the lateral folds. These
are not coloured differently from the surrounding parts, as are
the lateral folds. The foot is distinctly webbed, but the webs
are deeply indented and two joints of the fourth toe are free.
188
THE FROG BOOK
PLATE LXXI
Ig&gfe,
The brook and the meadows nearbv make the home of the Pickerel Frogs.
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The Pickerel Frog
The inner sole tubercle of the foot is small; the outer still smaller.
The palm of the hand has well-developed tubercles.
Range: The Pickerel Frog is found throughout the eastern
part of North America, west to the Great Plains, and north to
Hudson's Bay.
If we go to the meadow for blue flags in May, we are likely
to hear the Pickerel Frogs (Figs. 221 and 222) croaking with low
voices in the quiet shallows of the meadow brook or of the pond-
margin near by. The prolonged note is very distinctive. It
is well described by saying that it resembles the sound produced
The Pickerel Frogs are croaking when the blue flags are in bloom.
in tearing resisting cloth of some sort. The pitch varies with
the individual, but is always low. The range is from G to A
below middle C.
As we approach the brook, picking our way over the boggy
ground with its sedges, sweet white violets and blue flags, many
small spotted frogs leap astounding distances on both the near
and the far side of the brook, striking the -water in a series of
successive splashes. The surface of the water is scarcely ruffled,
and the frogs are immediately buried in the mud or hidden under
shelving bits of moss at the brook's edge. The Pickerel Frogs
are even more agile than the Common Leopard Frogs.
The brook and the fields and meadows near make the home
of the Pickerel Frogs, and we shall find them here in all sizes,
from those one year old and only an inch and a quarter long to
large ones that are three inches in length.
There is perhaps no other of our frogs that presents a coat
189
Ranidse
of so brilliant a metallic lustre as the young Pickerel Frog after
he has been in bright light for some hours. Shining gold and
bronze make up his colour from the tip of his little pointed " nose "
to the ends of his long back legs. On the other hand, the young
Pickerel Frog just from a cold day's sleep in the mud is so dark
that his spots are scarcely discernible.
The appearance of this frog will deceive us into believing
that he is our familiar Leopard Frog, unless we are observing
enough to see that the spots are square instead of round, and
that as he makes one of his flying leaps there is a flash of orange
under the back legs and posterior part of the body. These
things mark him as a Pickerel Frog. He is in fact very closely
related to the Leopard. However, he is always brown of some
shade, instead of green. The head is usually less long and pointed
than that of the Leopard. The spots do not have yellow rims.
The Pickerel Frog has no large external vocal pouches, like those
of the Leopard, but the throat, the region back of the eye and
under the ear, as well as the sides, all expand considerably
during the croaking. The male is much smaller than the fe-
male. It is he alone that does the croaking. This species has
a distinctly unpleasant odour, due to the secretion of the skin.
Because of this, it is not considered edible. The frog is used
to a large extent as bait in pickerel-fishing, hence its name.
These frogs live out of the water (Fig. 221) more than in it,
even at the breeding season. They go to the water to avoid
their bird and snake enemies, to lay the eggs, to absorb the cool
water through their shining coats. They spend the greater
part of their time hunting, probably for caterpillars that feed
on the violets and grasses, meadow caddis flies, butterflies
and millers, flies, gnats, and beetles. It is likely that Pickerel
Frogs find acceptable any insect that makes its home about the
brook or that comes there to deposit its eggs in the water or to
get honey from the flowers that grow there. They are known
to feed on snails, small crayfishes, and aquatic amphipods and
isopods. Pickerel Frogs are extremely common throughout
the Eastern part of the United States. They are not to he found
at all on the Great Plains of the West, where the Leopard holds
supreme sway among frogs. They make their home not only
in brooks and meadow marshes, but do good work in keeping
pure the water of cold springs. We see their large eyes and
190
The Pickerel Frog
palpitating white throats also in crannies at the mouths of surface
drains.
The eggs of this species are laid in shallow water during the
month of May. Frogs brought from the pond laid eggs on the
nights of May 18, 23, and 26, 1902. The irregular egg
masses are about two inches in diameter, and contain between
two and three thousand eggs each. The upper half of the egg
is rich brown in colour; the lower half cream-white. The eggs
are small (i J mm.) and enveloped in triple spheres of transparent
jelly. The earlier stages of the development take place very
rapidly. The jelly holds its compact shape but a very short
time; it softens, and the whole mass spreads and flattens. The
tadpoles, which are light yellowish-brown in colour, leave the
eggs very early. Eggs laid May 23rd were hatched May 2yth.
The tadpoles cling to the jelly side by side in rows and circles,
with their heads up and their tails extending downward. The
next day they are festooning the waterweeds as well as the jelly.
Now they begin those circling tours, from which they settle to some
new support, only to start off again in large circles, which give
place to smaller ones until they find another support or drop
lightly to the bottom. By the first week in June, the gills have
become wholly covered, and the bits of life have grown to ordinary
round-bodied ' pollywogs," with the usual pollywog hunger.1
From now on they vary greatly in size, some far outstripping
the others, although all live under the same conditions. The
larger ones change to the frog form in July and August; the
smaller ones may be kept back in the process until September;
and still others may delay the change until the following spring.
Large tadpoles of the Pickerel Frog have at first sight much
the appearance of the Green Frog tadpoles. Looking more
closely, we see that the head is much more pointed, the eyes are
not widely separated, and the nostrils are close to the end of the
muzzle, characteristics which distinguish this species. The
younger tadpoles have small roundish spots irregularly placed
on a greenish-brown background of body and tail. The dark
pigment follows the lines between the muscle-plates of the tail
so that for nearly one half its length the tail looks like a black
feather. The tail fin is less than one-fourth of an inch wide
1 The mouth structure of the pickerel frog tadpole is similar to that of the bullfrog tadpole.
(See footnote, p 235.)
Ranidae
everywhere. The lateral line organs, especially in the region of
the head, are very conspicuous. As soon as the hind legs are
well grown, and before the front ones appear, the lines of the
lateral folds begin to show, the square spots are blocked out on
the back, and the legs become barred with dark. After the
appearance of the front legs the swellings in the region of the gills
are very noticeable, as are also the lines from the nostrils to the
eyes.1
Just before the completion of the metamorphosis, while
the stump of the tail is still present, and just as the swellings in
the gill region disappear, the young frog moults its skin. It
now leaves the water and wanders over the grassy places at the
margin of the water. It is slender and delicate, and very shy.
At our approach it escapes with enormous leaps into the protec-
tion of the pickerel weeds and cat-tails that grow in the shallow
water.
RANA AREOLATA, B D. AND GIRD.2
IDENTIFICATION CHARACTERISTICS
Colour: Brown or olive, obscurely mottled and speckled
with light. Many large or small rounded spots on head, back,
and sides. There may be four irregular rows of these spots
between the lateral folds. The spots usually do not encroach
on the lateral folds. There may be yellowish-white outlines
around the spots. Ear brown, with a white blotch at its centre.
Upper and lower lips coarsely marbled with brown. Legs spotted,
or crossed by four dark bars. Much yellow on femur and body
where they fold against each other. Underparts white. (Figs.
223 to 225.)
Measurements: Size medium, i. e., length 2^ to 3! inches.
Length of head contained in total length three times. (Fig. 223.)
Length of leg to heel equals length forward to eye or nostril.
Tibia longer than femur. (Fig. 225.)
Structure: Skin rough, with elongated warts on back and
sides. Lateral folds conspicuous. Tibia ridged lengthwise.
1 See Bull Frog, pp. 236, 237.
2 Judging from measurements made on the type specimens in the National Museum, Rana
areolata Bd. and Gird, is the same as Rana areolata circttlosa Rice and Davis and as Rana areolata
capita Le Conte.
192
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THE FROG BOOK
PLATE LXXIV
FK.S. 22610 22S.— A'tfH tfso[>ns Cope. Ozona, Florida. (For coloration see Colour Plate XIV.) This frog lives solitary in
the burrows of a highland turtle. Its greed is uuequaled even hy that of the American Bullfrog. (Note the development
of the head and jaws.)
The Gopher Frog
No glandular fold along the jaw. A distinct fold over the ear
from eye to shoulder. Under and posterior surfaces of femur
granulated. Head large; unusually thick through. Muzzle long;
space between eyes greater than width of eyelid; nostrils nearer
to the end of the muzzle than to the eye; eyes large; ear half to
two-thirds size of eye. (Figs. 223 to 225.) Foot with a tarsal
fold; webs short (three joints of fourth toe free); inner sole
tubercle small, no outer tubercle, tubercles under toe-joints
prominent.
Range: Rana areolata probably occupies the Austroriparian
subregion. It is reported from Texas (Hitchcock, Indianola)
and Georgia (Riceborough). There is also a record of single
specimens having been collected in Indiana and Illinois.
This frog has the hiding instinct thoroughly developed, as
has Rana asopus of Florida. Like the Florida frog also, it has
unusually large vocal pouches that can be extended from the
shoulder regions. It is a silent, solitary frog, except at the
breeding season.
The species can always be distinguished from Rana cesopus,
by the lesser development of the jaws in width and massiveness,
and because the ratio of head and body measurements are as
one to three, instead of one to two and a half.
THE GOPHER FROG
Rana cesopus Cope
IDENTIFICATION CHARACTERISTICS
Colour: Brown, dark or light in shade. This colour may
be purplish, greyish, or yellowish in tone. The broad lateral
folds are bright orange-yellow. Warts on back and sides, often
bright yellow. Many closely set black spots on the head and
on the back between the lateral folds; many smaller black spots
on the sides. The spots on the back and on the sides infringe
upon the yellow lateral folds. Upper lip spotted, not light or
dark bordered. Ear dark, with irregular spot of light in centre.
Glandular fold along jaw to shoulder yellowish. Legs with
Ranidae
four or five black or dark brown cross-bars. Foot and hand
dark; tubercles of hands and feet light in colour. Underparts
spotted, especially anteriorly. (See Colour Plate XIV.)
Measurements: Size medium to large, i. e. length 2\ to 4
inches; female larger than male. Head long, its length con-
tained two and a half times in total length. (Fig. 226.) Head
of a frog 3 inches long measures \\ inches wide and i^ inches long.
Length of leg to heel equal to length of body forward to ear or
eye. Femur and tibia about equal. Foot long, fourth toe ex-
tremely long; web medium in size. (See Fig. 228.)
Structure: Body peculiarly short and squat. Skin leathery,
and corrugated with elongated wart-like folds on back and sides.
Tibia ridged lengthwise. Lateral folds broad and elevated.
The glandular folds of the jaw end above the shoulder in peculiar
large warts. Ridge from eye to shoulder (over ear) inconspicuous.
Eye unusually large and prominent. Nostril equidistant between
eye and jaw. Ear a vertical oval, half to two-thirds size of eye.
Space between eyes less than width of eyelid. Fingers long and
slender; the thumb of the male is thickened and horny at its
base (Fig. 228) ; hand tubercles not notable for size. Legs stout
and strong; inner sole tubercle relatively large and long, outer
small or lacking; tubercles under joints of toes rather conspicuous
(Fig. 228).
Range: Rana asopus Cope is reported from Florida only
(Micanopy, Orlando, Ozona, Lake Jessup, Clarcona).
The Gopher frog of Florida is very different from other
frogs in its general appearance. It is squat and toad-like, having
an unusually large head, with a prolonged muzzle, and eyes prom-
inent and bulging even for a frog. Because of the unusual length
and breadth of head, this frog has a mouth relatively larger than
those of other North American frogs. (Fig. 227.) These struc-
tural characteristics give the frog so peculiar an appearance that
although it may agree with Rana palustris and with Rana pipiens
in colour and in being prominently spotted, there would never
be any difficulty in distinguishing it as a different species. (See
Colour plates XI, XIII and XIV.)
The male frog has two large vocal pouches (one at each
194
The Gopher Frog
shoulder). These can be extended between the arm and the
glandular fold above. When the pouch is not inflated, the
region back of the angle of the jaw and between the arm
and glandular fold (which extends fully one-half inch behind
the jaw angle) is occupied by broad folds of thin dark-coloured
skin.
The general colour of these frogs varies considerably. It
may be grey or brown, somewhat yellow or purple in tone. The
spots may vary in size and in number. In any individual frog,
the colour changes are striking and rapid. The frog may change
from nearly black to white, through shades of brown or purplish
grey. The spots keep their intensity when the frog is light in
colour. (Colour Plate XIV.) In the light-coloured frog, yellow
colour is very prominent. It is not only on the elongated warts
and lateral folds, but extends from the lateral folds over the eyes
along the canthus rostralis to the nostrils. The secretion of the
skin given off when the frog is annoyed is offensive in odour.
Thisjrog is so wary and has such strong habits of hiding,
that but few specimens have come to light. The wariness of
this species has resulted in a habit of spasmodic instead of con-
tinuous activity. Its method, like that of the cricket grass-
hopper, is ludicrous to observe. It remains absolutely quiet for
minutes at a time, relying on its protective colouration until the
danger is well-nigh upon it. When the movement comes, it is
with startling suddenness and despatch, leaving the frog statuesque
again and observant, but in a new place.
Rana asopus is comfortable in water, though not conspicu-
ously a water-frog. It sits with head and shoulders protruding
from water-weeds, invisible because of the colour and spotting
of its dress. When the air becomes cooler than the water, it
withdraws under the surface, and rests for hours, even days, at
a time, with motionless flattened body, closed eyes, and arms
and legs in hibernating position.
Outside of the breeding season, it lives solitary in gopher-
holes, hence its name. These so-called gopher-holes are the
burrows of a Florida highland turtle. The burrow — about eight
inches high, and fourteen wide, and sometimes as long as thirty
feet — extends obliquely and irregularly through the sandy soil,
starting under a clump of palmetto, or under a log, stump, or fence.
The frog sits at the mouth of the burrow, watching for an unsus-
Ranidae
pecting insect, bird, or batrachian. It disappears so quickly
at the approach of danger, that not only is it seldom seen, but,
to be captured, must in all cases be dug out of the burrow.
This frog seems especially fond of toads as an article of diet.
It ejects the poison from the mouth as soon as it has swallowed
the toad. A toad of surprisingly large size can be managed,
owing to the unusual development of the jaws and throat of
this species. If the toad is too large to be all swallowed at once,
so that the poison can be sent out through the mouth almost
immediately, the frog gives up the attempt and disgorges the
toad after about fifteen minutes. This time, however, is sufficient
to allow some action of the poison to take place, and the frog
shows many signs of discomfort. It has convulsive movements
of the muscles, it leaps blindly upward, and finally, lowering
the head and opening the cavernous mouth, uses the hands in
frantic efforts to remove the irritation from there. During
several weeks of captivity, Rana asopus fed almost wholly upon
toads, of species lentiginosus, woodhousei, and jowleri. This
habit of eating toads may be duplicated in the case of Rana
catesbiana. At least this frog has been found dead witn full-
grown specimens of Bufo jowleri partially swallowed.
RANA ONCA, COPE '
IDENTIFICATION CHARACTERISTICS
Colour: Brown posteriorly; lighter anteriorly, often bright
metallic green, especially on sides of head under the eyes and
below the canthus rostralis. Iris golden. Ear bronze. Lateral
folds light yellowish brown. Three or more irregular rows of
spots between the lateral folds, and many spots placed irregu-
larly below the folds. Spots light edged or not. Legs light
brown, spotted with dark, even on the feet. Underparts white,
yellow posteriorly. (See Colour Plate. II.)
Measurements: Size medium, i. e. length 2 to 3 inches.
Leg short ; length of leg to heel equalling length of body forward
to eye. Tibia but slightly longer than femur.
i Rana jisheri Stejneger. Annotated List of Reptiles and Batrachians Collected by the Desert
Valley Expedition in 1891. Leonhard Stejneger. North Amer. Fauna, No. 7. 1893.
Also Rana draytoni onca Cope. Cope's Batrachia of North. America.
196
Rana Onca
Structure: Skin smooth, except for lateral folds and a few
inconspicuous elongated wart-like elevations on the back between
the lateral folds and on the sides. Head rounded, thick through,
with much the proportions and appearance of the head of Rana
clamitans. (Fig. 257.) Ear larger than eye in male, slightly
smaller than eye in female. No conspicuous ridge over ear.
No glandular fold along jaw. Feet delicate; webs broad and
long. Inner sole tubercle small; outer lacking.
Range: Rana onca Cope is reported from Utah and Nevada.
This species of frog (Fig. 257 and Colour Plate II) is not
nearly related to the black-cheeked frogs of the Pacific Slope.
It is apparently much nearer the eastern Rana clamitans, and the
spotted frogs Rana pipiens. The general colouring, also the
shape and proportions of head, body, and legs are remarkably
like those of Rana clamitans (Fig. 230); the spotting reminds
one of Rana pipiens (Fig. 197), but differs in that it represents
a temporary colour pattern instead of a permanent one. Rana
onca never attains the size of either of these other frogs.
Rana onca is a very bright, active little frog. It eats worms
and insects greedily. It will try to take a worm away from a
companion frog, biting at the frog's head again and again. In
locomotion it proceeds by short hops, given in quick succession
with short toad-like legs.
The power for rapid change of colour is considerable. The
frog may be brown or green, of light or dark shade. The spots
may or may not be rimmed with light colour. They may be
darker or lighter than the background of colour. When lighter,
they are shining gold or bronze. There is much iridescence in
the colouration. In fact, the young frogs may wear a coat
everywhere rich in metallic lustre.
The frogs examined have shown no external vocal pouches.
The large webs and the unusually large tympanum make this
frog easy of indentification within its western range.
197
Ranidae
THE GREEN FROG
Rana clamitans Latreille.
IDENTIFICATION CHARACTERISTICS
Colour: Extremely variable and changeable. Typically,
the colouring is brilliant metallic green on head and shoulders
and dusky olive (perhaps spotted) posteriorly. There may be
a yellowish band (widening anteriorly) along the lines of the jaw
from the shoulder forward. Throat of the male bright orange-
yellow; that of the female, white, spotted with dark. Sides of
the body often marked with large blotches of dark. (This is especi-
ally true of the female.) Legs spotted or barred with dark.
(See Plate XIII for colouration of the Green Frog.)
Measurements: Size somewhat above medium, i.e. male,
3 to 3i inches, female 3 to 5 inches. Legs relatively short; the
length of the leg to the heel being much less than the combined
lengths of head and body. Tibia and femur about equal in
length.
Structure: The skin may be rough. Head unusually thick
through. Head somewhat pointed. Ear of male much larger
than the eye; that of female no larger than eye, often smaller.
(Figs. 229 and 230.) Body stout. Lateral folds conspicuous;
a groove occupies the midline of the back. The web is broad;
it leaves the last two joints of the fourth toe free. (Fig. 231.)
Range: Very common throughout eastern North America,
including Canada and Florida.
As we walk along the path that skirts the meadow brook,
we are surprised by a scream, followed by another and still another.
Our curiosity demands that we investigate. The sound suggests
a frightened bird, though there is almost no shrubbery for the
concealment of a bird. We walk more slowly, and approach
the brook. There is nothing to be heard now, except the occa-
sional splashing of water as a startled tadpole rushes to safety
from the shallow water; or the whirring of wings as a dragon-fly
passes startlingly near to our faces. We walk on along the
1 Called " Spring Frog " and " Pond Frog " in various parts of the country.
COLOR PLATE XIII
Fig.!.— GREEN FROGS. Male and Female. [Ranacl•*** •* - — * A *- (^
The home of the WOOD FROG (Rana y/ratica Le Conte).
THE FROG BOOK
PLATE LXXVIU
1 2
FIG. 242 (i).— The WOOD FROG covers more ground in a single leap than do most of our other frogs. Photo-
graphed to show length of hind legs, also the lateral folds and other distinctive characteristics.
FIG. 243 (21.— The WOOD FROG in resting position.
FIG. 244 (3).— Very alert. The WOOD FROG can always be known by its dark cheek patches.
FIG. 245 (4).— The WOOD FROG (Rana sylvatica Le Conte) is a typical land frog. Rhode Island.
The Eastern Wood Frog
Step forward ever so little, and bend down to pick a spray of
red-tipped pyrola flowers, and a frog will leap almost from under
your very hand. It is hard work to catch a half-dozen of them,
and good fun to make them swim in the near brook. The
work comes first, for the ground is uneven and these atoms of
frogs leap enormous distances, never twice in the same direction.
Besides, they are not easy to keep after they are caught. They
are strong and slippery, and they are so delicate that they must
be handled with great carefulness. The fun comes when we
release them in the water. They are powerful swimmers, and
kick out their hind legs vigorously. However, they make for
the nearest miniature island, or for the shore, where they are
hidden, and we have at once lost all but one or two. It makes
us very active indeed to keep trace of these; before we are aware
of it, they, also, are gone.
However, we saw them long
enough to realise that they were
slender and delicate in shape, grey
or brown in colour, and that they
had black or dark-brown cheek-
patches. They are one-year-old
Wood Frogs. Wood Frogs are
more truly land frogs than are
any of the others among our
North American frogs.
In addition to these very
small frogs, we are certain to come
upon larger Wood Frogs, two
years old or more. We are most
likely to find them along wood
paths or at the edge of the brook.
Land-life, and the broader
experience resulting therefrom,
seems to have produced a some-
what higher development in this
frog. It not only looks much
more intelligent, but it is certainly
less unintelligent in some of the
ways of its living, than other frogs.
It jumps farther than most of the June.
207
The waxy flowers of the pipsissewa.
Ranidae
others, and has the habit of turning during the movement, so that
when it strikes the ground it is facing the enemy. It is much more
alert in getting food, resembling the toad in this respect. It sees
the moving insect at a distance of several feet, stealthily walks
or creeps toward it, and perhaps follows it some distance, before
making the capture. Besides, the Wood Frog is our most silent
frog, in this, again, resembling the toad. It is only at the early
breeding-season that its hoarse croaking can be heard. When
a creature lives on the ground, and has no manner of defense,
and none of escape, except jumping (and that always on the
ground), silence must be a great protection.
The Wood Frog may measure 2^ or 3 inches in length.
Its head is pointed. The body is broad and flat. (Fig. 243.)
The legs are extremely long, measuring twice the length of the
head and body together. The hind feet are strongly webbed.
The upper parts are light or dark reddish, yellowish, or greyish
brown in colour. This frog is distinguished within its own range
by the dark-brown or black cheek-patches. A distinct dark
line reaches from the front of the eye to the end of the muzzle.
A golden yellow line extends along the sides of the upper jaw
and is continued to the shoulder. The eyes, which are larger
than the ears, are very orominent, and possess an alert, but gentle
expression. The golden iris shows a lower half much darker
than the upper. The light-brown lateral folds, extending from
the eyes to the posterior end of the body, are very conspicuous.
(Colour Plate XIV.) The male Wood Frog, when held in the
hand, talks in a vigorous purring voice, something like that of
the Common Leopard Frog.
Very early in the spring, the Wood Frogs come from their
winter sleep under the leaves and mossy logs. In fact, they are
the first to be enticed by the spring sunshine. In February or
March, after only a few days of moderate temperature (40° to 60°
F.), the frogs are out and the eggs are laid1 in the pools of the
woods or of the open country adjacent. The eggs are laid in
masses which measure about four or five inches in diameter, and
which contain from one thousand to three thousand eggs each.
1 March 23, April 2, 1882. W. H Hinckley, Milton, Mass.
February 23, March 8, 1890. T. H. Morgan, Baltimore, Md
April 4, April 10, 1904. After an unusually severe and prolonged winter. (The eggs were
hatched by April 23.) M. C. Dickerson, Providence, R. I.
208
The Eastern Wood Frog
(Figs. 246 and 247.) The masses may be attached to twigs and
grasses in shallow water, or they may be free.
After the eggs have been in the water a week or more, the
mass flattens and spreads greatly, and rests on the surface of
the water. There are likely to be several masses close together
in the water. The jelly about the eggs becomes green in colour,
and thus the egg-masses bear a close resemblance in position and
appearance to the floating masses of green pond-scum. The
green colour of the jelly about the eggs is due to the presence of
innumerable microscopically small green plants. The relation
between these plants and the developing egg is one of mutual
advantage. The plants feed upon the large amount of carbon
dioxide breathed out by the young tadpoles, and the tadpoles
get, as their share in the partnership, the free oxygen that the
plants give out as a waste product from their starch-forming
process. This oxygen must be of infinite value, produced every-
where in the midst ot the egg-mass, because it supplies sufficient
pure air for breathing, in spite of the crowded condition of the
two thousand or more growing tadpoles.
These egg-masses are not easily found, partly because they
are so inconspicuous, and partly because our attention is rivetted
on the very conspicuous jelly masses (Fig. 249) of the spotted
salamanders,1 or of the marbled salamanders1 (which choose the
same time and often the same place for depositing eggs). Eggs
that are laid in water that afterwards freezes are not killed,
and will develop as soon as a higher temperature returns.
As has been said, the hoarse croaking of the Wood Frog is
heard only at the breeding-season. At that time, however,
dozens of the frogs croak together in a most clamorous fashion.
The repeated notes are low-pitched (about an octave below
middle C). The notes have
been compared to the quack-
ing of ducks, but near at
hand, at least, they are much
less unmusical. The males alone do the croaking. They have
no external vocal pouches, but, as in the Pickerel and Green frogs
the throat and sides of the body over the lungs distend consider-
ably as the sounds are produced. The breeding-season is likely to
r
1 Amblystoma punctatum or Amblysloma opacum.
209
Ranidse
be over before the first of May. (Fig. 250.) After that time
their voices are never heard.
In colour, the eggs are chocolate-brown above and white
below. If laid early, they develop very slowly, requiring at
least a month to reach the hatching stage. (Fig. 248.) If laid
later, when the temperature of the water is much higher, the
development is so much more rapid that the tadpoles may hatch
in nine or ten days. The development is especially rapid in
shallow temporary pools. The young tadpoles are nearly black
in colour. The external gills become considerably longer and
more branched before their absorption than do those of the
Leopard Frog. (See Fig. 210.)
The tadpoles of the Wood Frog eat1 not only the green
jelly-mass from which they themselves hatch, but also the soft
green spheres within the jelly-masses vacated by young salaman-
ders. Like other tadpoles, they act as scavengers by greedily
devouring all dead animal matter of the pond.
In late May, the margins of the ponds will be found swarm-
ing with young Wood Frogs with tails of varying lengths. The
frogs (minus the tails) are f inch long, about the size of a male
adult Pickering's Hyla. Their hind legs are extremely long,
and the webs are fully developed. The lateral folds show red-
brown on a dark wood-brown background. The young frogs
are active and shy.
In permanent ponds or in deep or well-shaded temporary
pools, the development is more slow, because the pool endures
longer, and the frog is somewhat larger when it leaves the water.
In late June, the brown leaves of the bottom of such a pond
are covered with Wood Frog tadpoles that just match the leaves
in colour. Many of them have the legs well developed, perhaps
the arms also. With their plump " pollywog " bodies and their
long waving tails, they are much larger than the young frogs
that have left the water.
The variation in colour among the Wood Frogs is great
indeed, and the colour changes are fairly rapid. The young
frogs are likely to be dark in colour, more often than light; and
when light, they are more nearly grey than brown. The older
ones vary from a colour so light that it might be called flesh-
1 The mouth structure of R. sylvaiica is like that of ^?. fatcsbiana (see footnote, p. 235), except
that the lower lip is broader and bears four rows of teeth, instead of three.
2IO
The Northern Wood Frog
colour, to a brown that is almost black. The female is
usually much lighter than the male. The Wood Frogs may
be either conspicuously
spotted and the legs con-
spicuously barred, or they
may show perfectly even
colour without trace of
spots or bars. Indeed,
conspicuously spotted and
barred frogs may lose all
trace of the markings with-
in the space of half an hour.
The change from light
brown to dark, or the re-
verse, may take place in
fifteen minutes only. (See
Colour Plate XIV.)
The Wood Frog is
beautiful at all times It
has a high-bred and delicate
air. It is to the ground
what the chickadee is to the trees --a gentle spirit of the
woods. Its appearance and ways are always in harmony with
the subdued light, the quiet, and the delicate mosses and frail
ferns that live in the shade of great trees.
THE NORTHERN WOOD FROG
Rana cantabrigiensis Baird
IDENTIFICATION CHARACTERISTICS
Colour: Dark brown to yellowish grey. A dark line from
the end of the muzzle extends backward on each side along the
canthus rostralis through the eye, to form a large patch of colour
in the region of the ear. A light line along the jaw from the
end of the muzzle to the shoulder. There may be a light dorsal
streak from near the end of the muzzle to the posterior part of
the body. Lateral folds light-coloured, and bordered below by
irregular line of black. Legs barred or spotted with dark.
211
Ranidae
Underparts light, more or less mottled with dark, yellowish
posteriorly.
Measurements: Size below medium, i. e. length 2 to 2| inches.
Distance between nostrils greater than width of the head between
the eyes. Legs long, length to heel just equalling total length
of head and body. (Legs shorter than are those of Rana sylvatica.}
Tibia equal to the femur and equal to one-half the total length
of head and body.
Structure: Skin smooth. Head pointed. Ear smaller than
the eye. Lateral folds not greatly elevated. Web large.
Range: The distribution of Rana cantdbrigiensis is wholly
northern. It is reported from Illinois, Michigan, Wisconsin,
and Minnesota northward to Great Slave Lake on the west and
St. James Bay on the east.
Rana cantdbrigiensis would be recognised at once as a species
closely related to Rana sylvatica, the Eastern Wood Frog. It
differs only slightly in colouration and general form. It can be
distinguished at once by the leg measurement; the leg to the
heel just equals in length the total measurement of head and body.
This frog has the same delicacy of beauty, the same gentle-
ness and alertness of expression, possessed by the Eastern Wood
Frog. It would be surprising to find any great difference in its
habits. It is probably silent, except at the breeding-season,
and is more thoroughly a land frog than are most of the species
of Rana.
Its relationship to Rana sylvatica is also shown by its
northern distribution, which provess ability to endure a lower
temperature than most frogs. (Rana sylvatica is the earliest frog
to appear in the spring in the northeastern United States.)
West of the range of Rana cantdbrigiensis, that is, from the
Great Slave Lake to Alaska, inclusive, the representative of
this frog is a subspecies, Rana cantdbrigiensis latiremis Cope.
The leg measurement will always distinguish this frog from
the Northern Wood Frog. The western form has short, stout
legs, the measurement to the heel never being more than three-
fourths the combined lengths of head and body (length to heel
equals distance forward to eye.) There are a few other differ-
ences plainly visible; for instance, distance between the nostrils
312
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THE FROG BOOK
PLATE I. XXX
FIG. 251 (i).— Structure study of Kami draytoiin Bd. and Gird. (Female. Half-grown.) South San Francisco, Cal.
FIG. 252 (2). — Photograph of foot of Rana draytonii (female) to show size and number of the tubercles on the sole and
under the joints of the toes. (In water.)
FIG. 253 (3). — Frog of Figs. 251 and 254. Note the length of the fingers.
FIG. 254 (4). — Photograph (in water) to show one possibility in size and arrangement of spots.
Rana Draytonii
is considerably greater than the width of head between the eyes,
and the webs are much larger than in either Rana cantdbrigiensis
or Rana sylvatica.
RANA DRAYTONII, BAIRD AND GIRARD
IDENTIFICATION CHARACTERISTICS
Colour: Female — Reddish brown on the upper parts, with
or without darker spots. The region below and behind the eye
(including the ear) may be dark brown in colour. A yellowish
band along the jaw from the shoulder to the eye. Arms, legs,
and upper sides irregularly spotted with dark; the legs may
be transversely barred. Underparts light, spotted, and marbled
with dark. Lower sides of body and underparts of legs and feet
bright red. Rich mosaic arrangement of black and yellow on upper
leg and side of body where they rest against each other. The
male is less rich in colouring. It is greyish brown or yellowish,
is more likely to be distinctly spotted, and has much less red.
In both sexes, the palm of the hand and the sole of the foot are
purplish grey in colour. (See Colour Plate XV.)
Measurements: Size large, i. e. adult males 2| to 4! inches
(Figs. 255 and 256), females still larger. The length of the head
is contained three times in the total length of head and body.
The lower leg is somewhat longer than the upper leg. The
length of the leg to the heel is not as great as the combined lengths
of head and body.
Structure: The skin is tuberculated, especially in old speci-
mens. (Fig. 255.) Buttocks granulated. Head broader than
long, rounded in front. Body broad and heavy. Canthus
rostralis fairly prominent. The ear is smaller than the eye.
(Fig. 251.) A glandular ridge extends backward from under
the eye, narrowing to the arm. This ridge is interrupted at the
angle of the jaw, and also back of this, where the curving ridge
descends from the eye to the shoulder. (See Fig. 255.) The
lateral folds are distinct, and are perforated with minute pits.
There is a conspicuous fold of skin over the ear from eye to
shoulder. The legs are massive in full-grown specimens. The
tubercles under the toe-joints are especially conspicuous. The
inner tubercle of the sole is medium in size; the outer, small or
lacking. (Fig. 252.) A distinct tarsal ridge. The fingers are
213
Ranidae
unusually long. (Fig. 253.) The first is thickened at the base
(male).
Range: Rana Draytonii is reported from various parts of
California, also from the mountains of Lower California. (From
Petaluma, El Dorado, Presidio, Fort Tejon, Carmel, San Fran-
cisco, and South San Francisco, California.)
This Western species, when half-grown, is a frog of much
beauty of form as well as of colouring and texture of skin. It
is very alert and intelligent-looking, and becomes tame in cap-
tivity. (Fig. 251.) When it has attained its full size, it is
much less attractive in appearance. The eye, although very
lustrous, seems too small for the size of the frog; the skin has
toughened and coarsened until it is leathery in appearance, and
is tubercular in structure (see Fig. 255), and the colouring is
much less delicate and beautiful.
This frog is hardy. It is partially aquatic in its habits,
remaining in shallow water much of the time and taking food
from under the water. It eats fish greedily, as does the Eastern
Bullfrog, and therefore must prove a menace in fish-ponds.
It is a very awkward frog, because of the massive build
and great length of its hind legs. (Figs. 255 and 256.) When
walking, it is ludicrous in appearance, and it is still more
ridiculous when it captures a fish from under the surface of the
water and swallows it. The frog tries to brace himself on the
long hind legs so as to use the hands, both at the same time to
keep the fish away from the angles of the jaws and to push it
into the mouth. To brace himself against slippery mud is not
easy, and besides, the frog loses his balance because both hands
are lifted at once, so he makes a great kicking and splashing
before he finally swallows the fish. This frog eats not only
fish, but also various water-insects, tadpoles, and smaller frogs.
This species is said to be one of the most cannibalistic of our
North American frogs. He eats worms and air insects, also;
among the latter, sow-bugs are said to be favourites.
Both male and female " talk " vigorously in a low-pitched
musical voice, when they are taken in the hand so that the feet
are unsupported. There is no appearance of distended vocal
sacs when the frog croaks.
214
COLOR PLATE XV
draytonii Bd. and Gird. Female, four or five years old.
South San Francisco, Cal. Photographed to show the coloring of
the upper and under surfaces. The frog at the left is in water.
/ gj7"?\.ys*;«p , : - ,
,/'jr>jtt:T4
Rana Draytonii
This frog can be recognised at once because of the presence
and distribution of red colour on the underparts. This colour
is vividly displayed on the sides when the frog is in sitting posi-
tion; considerable red is sometimes found on the upper surfaces
of the body and legs, blending with the rich chocolate-brown
of the upper parts. (Colour Plate XV.) The dark brown or black
patch of colour in the region of the ear will help to identify the
frog sometimes, but very often this spot is no darker than the
background of colour elsewhere. The iris is rich orange-bronze,
instead of yellow, as in its near neighbour, Rana pretiosa. But
from this species the smooth, firm texture of the skin on the soles
of its feet will at once distinguish it. (See Fig. 252. Compare
with Fig. 263.) The tubercles under the joints of fingers and
toes are unusual in size. There is great variety in the size and
appearance of the spots on different individuals. Some are
almost plain in colour and some are conspicuously spotted.
The spots may be of large size (see Fig. 256) or very small.
They may be spots of solid colour or may have lighter centres.
(Fig. 254.) The spots may infringe on the lateral folds, in fact,
sometimes small spots are aggregated along the lateral folds.
For the exact webbing of the toes, see Fig. 252. The web
of the male is broader than that of the female. The first finger
on the hand of the male is thickened and hardened at its base,
and is dark-coloured and horny, especially on its upper surface.
All of the fingers are unusually long. (Fig. 253.)
Rana draytonii hibernates in the mud at the bottom of ponds
and creeks in winter, when the air is colder than the mud and
water. Here the frogs would be at the mercy of their enemies —
the large water-beetles, water-snakes, and especially the leeches,
except that the cold affects these enemies in the same fashion,
and they are sleeping also.
In the region of middle California, this frog comes from
its hibernation in late January or in February. The large egg-
clusters are laid at once in the shallow water of ponds. It is
said that the eggs hatch in about six weeks, and that the tad-
poles become young frogs in four or five months.1
The young frog is very small in the first year and still during
the second and third years, — in fact, it takes four or five years
1 Facts given by S. C. Coombs, Frog Ranch, South San Francisco, Cal.
2I5
Ranidae
for it to attain a length of two and a half to three inches, and
eight years or more to become full-grown. It is said by people
of the Western Coast that RanaDraytonii is the best edible frog in
North America, and that the flesh of the Eastern Bullfrog is
tough and coarse compared with it.
RANA AURORA, BAIRD AND GIRARD
IDENTIFICATION CHARACTERISTICS
Colour: Brown, yellowish, or olive, often matching the colour
of dead leaves. There may be small spots or specks of dark
brown or black on head, back, and sides. Space behind the eye
and including the ear may be black. A black line below canthus
rostralis from eye to jaw. Iris golden yellow. Glandular fold
from under eye to shoulder, yellowish. Upper and lower lips
spotted with dark. Arm may be crossed by 3 to 5 narrow dark
bands. Much red in the colouration, showing on the parts of
legs and feet which are concealed when folded, on the sides of
the body, and under the arms at their insertions. Reticulations
of yellow and black on body and femur where they lie against each
other. Throat and underparts light, obscurely mottled with
dark. Hand and foot may be purplish grey in colour. (For
colouration, see Plate XIV.)
Measurements: Size medium, i. e. length 2^ to 3^ inches.
Length of head enters total length three and a quarter to three
and a half times. Leg very long, its length to the heel exceeding
the total length of the head and body. Tibia much longer than
femur. (See Colour Plate XIV.)
Structure: Skin very smooth, finely pitted. Buttocks
granulated. Broad lateral folds perforated with pits. Groove
along the middle of the back. Body flat, long, and slender.
(Fig. 258.) Muzzle rounded. Canthus rostralis prominent. A
glandular fold of skin along jaw from under the eye to the shoul-
der. Eyes large, prominent, facing outwards. Space between
eyes equal to or greater than the width of the eyelid. Ear round,
one-third to one-half the diameter of the eye; it is likely to be
inconspicuous when the cheek-patch is dark. Ridge from pos-
terior angle of eye to shoulder not prominent. Tibia ridged
lengthwise. Arms and legs slender. Fingers long and slender;
216
THE FROG BOOK
PI.ATR LXXXI
FIGS. 255 and 256. — Male frog of Raiia diavtuini Bd. and Gird., eight or more years old. Slightly under natural
size. South San Francisco, Cal. The missive legs are conspicuously banded and the back has many large dark spots.
The skin is leathery and tubercular.
THE FROG BOOK
PLATE LXXXII
FIG. 257.- — Rana onca, Cope. Las Vegas, Nevada. Immature frogs, il/4 in. long. (For description see
page 196 ; for coloration see Colour Plate II.)
FIG. 258.— Rana aurora Bd. and Gird. Seattle, Washington. (For coloration see Colour Plate XIV.)
FIG* 259 —Rana aurora Bd. and Gird. (For description see page 216.)
Rana Aurora
base of first finger greatly thickened in male (Fig. 258) ; tuber-
cles under finger-joints fairly conspicuous. Foot not thick,
web delicate, with two joints of fourth toe free; inner sole
tubercle'small, outer small or lacking. (Fig. 259.)
Range: Rana aurora occupies the Pacific Slope. It is
reported from Washington, Oregon, and California. In Cali-
fornia, where Rana Draytonii is the common frog, Rana aurora is
said to be found in the high Sierras only; in Oregon and Wash-
ington, it is abundant, but is less so in many parts of these
states than is Rana pretiosa.
Rana aurora is a delicately formed, smooth frog, less hardy
than most frogs of North America. (See Figs. 258 and 259, also
Colour Plate XIV.) It is shy and wild, and difficult to keep in
captivity, except in a perfect imitation of its environment. In
such a place, it seems to enjoy equally sitting under the shade
of ferns or in the water, and eats earth-worms greedily. Both
male and female give high-pitched, jerky cries, expressing fright,
when taken in the hand. One unusually large specimen opened
his mouth wide and gave a prolonged high-pitched scream, remind-
ing one of the similar sound produced by the Common Bullfrog.
Judging from the radical difference in the sizes of the frogs
to be found in the spring, this frog requires four or five years to
become full-grown. It changes colour rapidly, from dark rich
browns to delicate shades of rosy tan. Rana aurora is a delicate,
timid-looking frog, but, notwithstanding the promise of its name,
it does not always compare in beauty with many of the other
frogs of North America. It seldom has the richness of colouring
that may be possessed by Rana draytonii, its neighbour on the
Pacific Slope.
Rana aurora is easily confused with Rana draytonii (Fig. 251
and Colour Plate XV), because of the likeness, both in colouring
and proportions. The former frog can be distinguished by the
following characteristics: It has a longer leg, the greater length
especially noticeable in the tibia. Its skin is very smooth,
while that of Rana draytonii, especially in the full-grown frogs,
is always tubercular, and may be extremely so (even on the ear).
Rana aurora has a longer foot with a broader web, but with a
much smaller inner sole tubercle.
217
Ranidse
THE WESTERN FROG
Rana pretiosa Baird and Girard
IDENTIFICATION CHARACTERISTICS
Colour: Variable; dull or bright yellowish or reddish brown
on head, back, and upper surfaces of arms and legs. Few or
many irregular, roundish black spots — like splashes of ink —
on the back between the lateral folds. Lower sides light yel-
lowish grey, unspotted. Underparts light, obscurely or con-
spicuously marbled with greyish brown. Salmon-red on under-
surfaces of legs, and in a more or less conspicuous U-shaped
marking on the belly. A light glandular streak from under the
eye to the arm, interrupted at the end of the jaw. Iris bright
yellow, noi orange-coloured or bronze. (See Colour Plate XVI.)
Measurements: Size medium, i. e. male 2 to 3 inches; female
3 to 4 inches in length. Leg to the heel as long as the body
(i. e. forward to the ear). Foot conspicuously longer than lower
leg. (Figs. 260 and 262, also Colour Plate XVI.)
Structure: The skin is everywhere rough, even in the region
of the ear. Lateral folds distinct. Head rounded, broader
than long. Ear smaller than the eye. Head not conspicuously
angled along the lines between eyes and nostrils. Nostrils
round. Eye not large, set obliquely, so as to be but slightly
elevated, and so as to face more dorsalwards than is usual.
The foot has broad webs extending to the tips of all the toes,
except the fourth, which has the short terminal joint free. (Fig.
260.) The whole lower surface of the foot, as well as the but-
tocks and outer surfaces of legs (especially of lower leg), very
rough with crowded tubercles. The inner tubercle of the foot
is small, and there is a small tubercle opposite this on the sole.
(Fig. 263.)
Range: Northwestern North America, as far east as the
foot of the Rocky Mountains in Montana, north to Puget Sound,
and south to southern California.
The Western Frog has been found during the winter, sleep-
ing in the mud under a foot or more of water, along marshy lake
218
COLOR PLATE XVI
THE WESTERN FROG [Rana pretiosa Bd. and Gird.
Female. Seattle, Washington.] Photographed (in water) to show
the coloring of the upper and under surfaces.
. r
f f'
The Western Frog
margins. It appears in the Puget Sound region from the last
of February to the middle of March. A few scattered individuals
may, however, be seen on sunny days throughout the winter.
These are usually among the lily-pads along the marshy borders
of the lakes.
As soon as they appear in March, they set up a noisy croak-
ing, and the eggs are laid between this time and the first of April.
The egg-masses (Fig. 261) are unattached. They vary greatly
in size, but average about a pint in bulk. In one case where
the eggs were counted, a laying consisted of over fifteen hundred
eggs. The eggs are relatively large, measuring nearly 2 mm.
in diameter. Each egg is in a transparent sphere of jelly meas-
uring one-half inch across. The eggs are placed in the shallow,
marshy pools near a lake, but never in the deep lake-water itself.
The length of time required for hatching is from one to two weeks,
varying with the temperature; those in the warm, shallow water
hatching earlier than those in deep water. The later develop-
ment is slow, and it is not until after the summer is passed that
the tadpole becomes a frog. This slow development is perhaps
correlated to the conditions of the region of the frog's range.
There is an abundance of water in this region, even in summer,
so that the development is not hastened by the drying up of the
pools.
From this time on the growth is slow; at least, there can be
found, each spring, frogs of four or five different sizes, so that it
would seem as though they require four or five years to reach
the adult size.
The adults are easily captured during the breeding-season.
As soon as we approach them, they dive into the mud of their
shallow pool, burying the head and shoulders, but leaving the
legs exposed in good position for capture. Their colouring is
highly protective. It is difficult to see them when they are
sitting among the alternating lights and shadows of the reeds.
They depend so much on their protective colouration, that they
lie low and allow themselves to be touched before taking alarm.1
This frog is distinguished from other Western frogs by its
round nostrils, the tubercular character of the soles of the feet,
the long foot and large web, and the lack of prominent lines
1 Many facts concerning this species were kindly furnished by Prof. J. F. Tiling worth, Seattle,
Wash.
219
Ranidae
from the nostrils to the eyes. The frog shows no salmon-red
colour when in sitting position, and so one's surprise is great
on discovering so much brilliant colour on the under surface of
the frog's body and legs. The undersurfaces of the arms may have
the same colour. The lack of red on the side distinguishes it
at once from Rana Draytonii (see Colour Plate XV), and from
Rana aurora, as does also, the lack of dark cheek-patches.
The position of the eyes also aids in the distinction.
As to colouration, this frog may be any shade of yellowish
or reddish brown, from the lightest to the darkest. The sides
are always lighter than the back. The legs are irregularly
barred and spotted with brown. The knees are likely to possess
the same light yellowish grey colour of the lower sides. The
male is considerably smaller than the female, and is likely to
be more spotted. The forearms are muscular, and the first
finger is thickened and hardened at its base. The feet and
webs are enormous for the size of the frog. (Fig. 260.) The
web has a spread of one and one-half inches on a frog only two
and one-half inches long.
When taken in the hand so that its feet are unsupported,
this frog " talks " vigorously, as do many of the frogs and toads.
This is true of both male and female, but the voice of the male
is louder and more emphatic. External vocal pouches do not
show when the frog croaks.
The Western Frog is thoroughly aquatic in its habits. It
gets its food largely from the water, feeding greedily on small
fish, as does its near neighbour on the Western coast, Rana dray-
tonii, and as does the Eastern Bullfrog.
It is interesting to watch the male swim in very shallow
water. With flattened body and lowered head, he searches
for something under which he can hide. Finding nothing, he
kicks out his powerful legs, alternately spreads and folds the
extremely large webs, and continues the search. He some-
times turns so sharply, that the body is entirely turned around
before the legs have had time to turn, and so for the moment
one leg ludicrously measures itself straight forward along the
body. Finally, some bit of moss is found under which the frog
can push his head, and there consider himself safe. So safe
does he feel, that almost immediately he lifts his head till nostrils
and yellow eyes are above the weeds and water. The eyes are
220
THF. FROG BOOK
PLATK LXXXIII
FIG. 260 (i).—Ranapretiosa. (Male). Seattle, Washington. The first finRer is thickened, the webs are unusually large
FIG. 261 (2).— A portion of the egg-mass of Kana pretiosa.
FIG. 262 (3).— Rana preliosa. (Female). Seattle, Washington. Distinguished by round nostrils, warty skin long foot
and light lower sides.
FIG. 263 (4).— Rana pretiosa. (Female). Structure study of foot.
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Rana Boylii
peculiar, in that they are little elevated at their upper margins,
and so face upward more nearly than sideways. This is one
ot the many characteristics that adapt this frog to a thoroughly
aquatic existence.
RANA BOYLII, BAIRD AND GIRARD
IDENTIFICATION CHARACTERISTICS
Colour: Dull olive or greyish brown; sometimes brick-red.
Upper surface may be obscurely spotted with dark. Upper
jaw spotted irregularly. Iris metallic yellow. Legs and arms
barred with dark. Underparts white, mottled anteriorly, and
bright yellow posteriorly. Much yellow around the arm inser-
tion. Webs yellow (See Colour Plate II.)
Measurements: Size small, i. e. length i^ to 2\ inches. Head
short and broad. (Fig. 265.) Legs very long; length to heel
equals the total length of the frog, and sometimes exceeds it.
(Fig. 265.) Tibia longer than femur.
Structure: Skin thick and coarse; unusually warty over
all upper parts. (Fig. 264.) Underparts smooth; buttocks
granular. Lateral folds broad, not elevated, very inconspicuous.
Muzzle projects beyond lower lip. Nostrils small. Ear round,
smaller than eye, indistinct because covered with fine warts, as
is the surrounding skin. (Fig. 264.) The fold extending over
the ear from eye to shoulder is indistinct. Canthus rostralis
prominent. Space between the eyes greater than the width
of the eyelid. Arms well developed; fingers long, with small
tubercles under the joints. Foot with broad webs extending
quite to the expanded tips of the toes. Inner sole tubercle
medium in size; outer tubercle small. (Fig. 266.)
Range: Rana boylii Baird and Girard, is reported from
California and Oregon.1
Rana boylii, which, in California, is called the Yellow-legged
Frog, has perhaps the most toad-like appearance of any frog
of North America, although it does not sit erect in toad fashion.
(Fig. 265.) The likeness lies in the texture of the skin. The
1 Eldorado County, Ashland, Ore Shasta County; Mill Valley, Maria County, Cal.
221
Ranidae
short, flat body is completely covered with small warts, from
the tip of the nose to the ends of the feet, producing a surface
that at first glance has somewhat the appearance of coarse sand-
paper. The frog is usually olive, grey, or yellow-brown, obscurely
spotted on the back (Colour Plate II), but often the whole
tubercular upper surface is bright brick-red. This red is some-
times to be seen on the lateral folds and on the tibia, when the
frog is brown or olive elsewhere.
Rana boylii is excessively shy and wild. Its first instinct
is to hide. It scuttles head-first under cover at any approach.
If there is no place of concealment, or if its hiding place is dis-
turbed, it leaps great distances, and the enemy who can capture
it must be alert of sight and grasp. This frog emits a curious,
oily odour, greatly like that given out by the California Toad,
Bujo balopbilus.
It has great power to change its colour from dark to light,
appearing nearly black at one moment, and light reddish or
yellowish grey half an hour later.
Rana boylii is one of the most distinct species of frogs in
North America. Within its own range, the yellow colour of
the underparts will suffice to distinguish it, since Rana dray-
tonii, Rana aurora, and Rana pretiosa, the other frogs of the
Pacific Slope, have red instead of yellow in the colouration. Com-
pared with all the frogs of North America, it is peculiar in the
tubercular character of the skin, though some specimens of
Rana draytonii approach it in this characteristic. Rana boylii
is like Rana pretiosa, Rana catesbiana, Rana grylio, and Rana
septentrionalis in the extensive webbing of the feet.
RANA VIRGATIPES, COPE
IDENTIFICATION CHARACTERISTICS
Colour: Chocolate-brown or brownish olive, with four narrow
lengthwise stripes of bright golden brown. There are two of
these stripes on each side. One occupies the position usually
held by the lateral fold (i. e. from the posterior part of the eye
backward) ; the other lies below this, and extends along the middle
of the side. The lower stripe is continuous with a stripe of bright
golden brown extending from the shoulder forward along the
222
Rana Virgatipes
jaw. Throat yellow, speckled with bronze. The sides of the frog
have large dark spots on a metallic, brownish yellow back-ground.
There are small black spots on the back and sides between the
stripes. The belly and undersurfaces of the arms are yellowish
white, spotted and mottled with rich brown. Under-surfaces of
legs vividly striped lengthwise with yellow and brown; stripes
continued on tibia and foot. (See Colour Plate XIII.)
Measurements: Size somewhat below medium, 5. e. length
2 to i\ inches. Head long; length contained three times in
total length. (Fig. 267.) Space on top of head between eyes
unusually narrow (half width of eyelid). Leg short (Fig. 268);
length of leg to heel equals length of body forward to the ear.
Tibia and femur equal. Foot relatively long; fourth toe much
the longest; third longer than fifth.
Structure: Skin relatively smooth and wet. Head pointed,
upper jaw projecting over the lower. Canthus rostralis promi-
nent. Eye peculiarly bulging (Fig. 267); extends beyond
the jaw on the sides of the head, so that it can be seen from
below. Ear larger than eye, and very distinct, surrounded by a
circular ridge of skin. Inconspicuous fold of skin from eye
over ear to shoulder. No lateral folds. A groove marks the
middle of the back. Fingers slender; first thickened at base.
Web broad and conspicuous; two joints of fourth toe free. Inner
sole tubercle of medium size; outer lacking.
Range: Reported from Atlantic City and Lakehurst, New
Jersey.
Rana virgatipes (Colour Plate XIII and Figs. 267 and 268)
was first discovered by Cope, at Atlantic City, in 1891. It was
found in company with Leopard Frogs and Green Frogs, in stag-
nant water, where sphagnum moss, bladderworts, and water-lilies
grow. In the summer of 1905, it was reported as very abundant
near this type locality.1
These frogs have been seen at Lakehurst, at intervals from
May to September. They occur rather abundantly in the ditches
about the cranberry-bogs, as well as in the lake itself. They
are often found seated on a lily-pad or on the sphagnum moss.2
i.Fowler, Acad. Nat. Sci., Philadelphia.
2 1 am indebted to William T. Davis, New Brighton, N. Y., for these facts, as well as for
material.
223
Ranidae
Rana virgatipesis decidedly a water frog, and is one of the least
hardy of the North American species. It has only average powers
of leaping and swimming, but its instincts for hiding are strong.
When disturbed, it disappears at once under floating water-weeds.
It differs from the other smaller frogs of North America in the
great development of the eyes and ears. It is like the bullfrogs
in lacking the lateral folds. It resembles the Leopard Frog,
in that the male frog has large vocal sacs that can be extended
at the sides behind and under the ears. It shows close relation-
ship in structure and habit to Rana grylio (pp. 227 to 227).
THE NORTHERN FROG
Rana sepientrionalis Baird
IDENTIFICATION CHARACTERISTICS
Colour: Light olive, with or without coarse vermiculations
of darker colour. There may be large irregular blotches of
brown on the sides and posterior back. No light stripe along the
jaw. Legs blotched or transversely banded. Underparts light yel-
lowish, unspotted. Buttocks yellow, with dark blotches. Posterior
surface of femur may be strongly reticulated with dark colour.
Measurements: Size medium, i. e. length 2 to 3 inches. Leg
measurement to heel equals body measurement forward to the
eye. Tibia and femur about equal in length.
Structure: Skin relatively smooth; finely pitted when ex-
amined closely. Underparts smooth. Buttocks but slightly
granulated. Body rather stout. Head narrow, rounded in
front. Space between the eyes narrow. Nostrils large, half-
way between eyes and tip of muzzle. Ear larger than the eye
in the male, smaller than the eye in the female. No lateral
folds, or only slight traces of them. Feet long, toes provided
with long, broad webs. Inner sole tubercle medium in size.
Range: Rana septentrionalis is wholly northern in its dis-
tribution. It is reported from the Adirondack Mountains,
from Lucknow, Ontario, and Fort Ripley, Minnesota, and from
Moose River and the Hudson Bay region.
It is thought that this species is intermediate in its charac-
teristics between some more primitive form and nearly all the
224
The Northern Frog
North American species of Rana. From some such form might
have come all of our frogs, except, perhaps, the black-cheeked
ones, such as Rana sylvatica, Rana draytonii, and the like. It
shows close relationship to the Green Frog (Rana clamitans) and
to the Bullfrog (Rana catesbiana) .
The Northern Frog is described as decidedly a river frog;
it is never captured in lakes and ponds. It is silent and unob-
trusive, solitary in habit, and thoroughly aquatic. We do not
see it in meadows or woods, but if we walk along the brook
margin or river bank, it will dive into the water, much as does
the Pickerel Frog (Rana palusiris) in a similar situation. It
hides under stones, among water-plants, or in the mud near
the centre of the stream, and may not return to the surface for
fully a half-hour. In this habit of remaining long under water
when frightened, it resembles the Common Leopard Frog (Rana
pipiens). When it does appear, just head and shoulders are
thrust out among the water-weeds at the border of the stream.
The Northern Frog eats water-insects, and sometimes small
fish.
The breeding-season is in June and July.1 The egg-masses
adhere to water-plants, and wave back and forth with the cur-
rent half-way between the surface of the water and the bottom.
Two years are required for the development and metamorphosis
of the tadpole. The full-grown tadpole with developing legs
may measure four inches in length, two and one-half inches
being the measurement of the tail. The tadpoles are the scav-
engers of the brooks and rivers. For instance, they will greedily
eat a dead brook-trout, leaving only a perfectly cleaned skeleton.
Both the frogs and the tadpoles give off a strong, disagree-
able odour when annoyed. This odour is said to be like the
scent of the mink, and this species of frog is often called the
Mink Frog.
1 June 24 and July 30, 1883. Dr J. H. Gamier, Lucknow, Ontario.
225
Ranidae
THE SOUTHERN BULLFROG
Rana grylio Stejneger
IDENTIFICATION CHARACTERISTICS
Colour: Head and shoulders usually vividly green; olive
posteriorly, with many irregular black spots. The whole frog may
be olive or rich dark brown. Ear orange-brown, with green centre.
Middle and posterior back may have four longitudinal bands of
bright orange-brown, alternating with bands of olive. Small black
spots on legs. Underparts light, unspotted, except posteriorly.
Throat of male bright yellow. Undersurfaces of legs may be mot-
tled and reticulated in coarse pattern with black and yellow.
Measurements: Size large, i. e. length 4 to 5 inches. Head
long, its length contained little more than two and one-half
times in the total length. (Fig. 269.) Legs medium in length;
length to heel equals length of frog forward to a point anterior
to the eye. Tibia same length as femur.
Structure: Skin smooth on the head, slightly rougher else-
where on upper parts (Fig. 274); when examined closely, seen
to be everywhere finely pitted. Head with pointed outlines,
gradually diverging backward to the widest part of the head
in the region of the middle point of the ear. (Fig. 271.) Eyes
greatly elevated and unusually large. (Fig. 273.) Space be-
tween the eyes narrow. Ear of male greatly larger than the
eye (twice the diameter) (Fig. 269); that of the female about
equals the eye in diameter. (Fig. 270.) Nostrils prominent,
near together; slightly nearer to the muzzle than to the eye.
Elevated fold of skin over the ear to the shoulder. (Fig. 274.)
A groove runs along the midline of the back. Arms and legs
very muscular. Fingers long. (Fig. 271.) Foot broad; webs
large, extending fully to ends of toes (all except fourth toe rela-
tively longer than corresponding toes of Rana catesbiana).
(Fig. 272.) No outer sole tubercle; inner sole tubercle small.
Palm tubercles and all subarticular tubercles small.
Range: Reported from Florida (Pensacola, Kissimmee,
Ozona) and Mississippi (Bay St. Louis).
This frog was first found in 1900 at Bay St. Louis, Mississippi,
but was not recognised as a distinct species until more material
226
THK FROG POOK
PLATE LXXXV
FIG. 263.— The SOUTHERN BULLFROG (Rana grylio Stejneger~). Ozona, Florida. A beautiful frog, very retiring
and thoroughly aquatic in habit. Usually vivid metallic green on head and shoulders, olive posteriorly. Head long and
pointed. Ear of male greatly larger than the eye.
:
FIG. 270.— Female of the SOUTHERN BULL-
FROG. The ear is no larger than the eye.
FIG. 271.— Photographed I in wuturi to show the long narrow
head, and the smooth character of the undersurfaces of the fingers
and toes. The breathing movements of the throat are suspended
under water.
THF FROG BOOK
PLATE LXXXYI
FIG. 272 (i). — Foot of Rana grylio. Toes long with inconspicuous tubercles and long broad webs.
FIG. 273 (2).— Head pointed ; eyes greatly elevated and close together.
FIG. 274 (3).— Structure study of Rana giylio. (Enlarged.) To show texture of skin, relative size of eye and ear, and
fold oi skin from eye to shoulder. The photograph shows the transparent nictitating membrane of the eye.
The Southern Bullfrog
was obtained some time later from Kissimmee, Florida. The
frog might be unknown now, if it had not been for the persistent
reports of its voice. The sounds produced are said to resemble
the grunting of a herd of pigs, thus differing entirely from the
familiar bass notes of the Common Bullfrog.
The frog is really very different in appearance from the
Common Bullfrog, not resembling it in shape, porportions of
body, or colouring. The long, narrow, pointed head, with its
large eyes set close together, tell the story at once. But other
evidences lie in the ratio of the lengths of head and body (com-
pare Figs. 269 and 278), in the greater length of toes (except
the fourth) (compare Figs. 272 and 282), and in the finely pitted
texture of the skin. In addition to all these points, there is
that of colouration. Rana grylio, in its brilliant phases of colouring,
furnishes one of the most charming studies in blended shades
of yellow, green, and brown, all of these colours showing metallic
lustre. Especially beautiful is the colouring of the undersurfaces.
This species shows great power of changing colour. It may
be brilliant or dull, light or dark/ green or brown. There may
be green as vivid as that of the anterior head region on the breast,
at each side, about the arm insertion.
The frog is shy and wary, and is seldom seen, except by
those who are looking for it. It lives in deep water, among
pond-lilies and other vegetation of the lake. It seldom leaps;
its strong instinct, when frightened, is to dive and hide.
Rana grylio shows close relationship to Rana virgatipes
of New Jersey in shape and proportion, metallic colouring, tex-
ture of skin, large size of eyes and ears, in lacking the lateral
folds, and in aquatic habits.
THE COMMON BULLFROG
Rana catesbiana Shaw
IDENTIFICATION CHARACTERISTICS '
Colour: Green or greenish brown, of light or dark shade.
The back and sides may be plain in colour or may be spotted
with dark. (Figs. 276 and 277.) The spots, when present,
may be distinct or connected. Arms and legs spotted or barred
227
Ranidae
with dark. Underparts white, distinctly or obscurely spotted
and mottled with dark. The throat of the male may be yellow.
The iris is either golden or reddish bronze.
Measurements: Size large, both male and female often
reaching a length of 7 to 8 inches. The leg to the heel is not
as long as the combined lengths of head and body. The femur
is about equal to the tibia.
Structure: The head is broad and flat. The body is stout
and flat. Ear of male much larger than the eye (Fig. 277);
the ear of the female is about the size of the eye. (Fig. 276.)
The lateral folds are lacking. (Figs. 276 and 278.) A strong
fold of skin extends from behind the eye to the arm, curving
around the ear. (Figs. 277 and 278.) Toes broadly webbed;
no joints free, except the last of the fourth toe. (Fig. 282.)
Range: Rana catesbiana Shaw is found in North America,
east of the Rocky Mountains (including Florida and Texas).
Bullfrogs are late in coming permanently from their hiber-
nation.1 It may not be until late May or early June that we
hear their deep bass voices from the ponds, or that we see their
gigantic green bodies perched on partially immersed logs or
floating among water-weeds at the surface. They prefer large
ponds or lakes, where they can find deep water as well as shallow,
screened from the shore by low willows, alders or other water-
loving plants. They like such places, also, because of the shel-
tering growths of pickerel-weed, arrowhead, and water-lilies.
(Fig. 275.) These make good hiding-places, and about the
roots and stems and under the leaves are to be found cray-
fishes, water-beetles and bugs, snails and shrimps, the larae
of dragon-flies and May-flies, and, in fact, all sorts of delicacies
for a water frog's menu. For the Bullfrog differs from the
Leopard and Pickerel frogs, in that it does not hunt in any place
except the body of water which makes its home. We shall not
find Bullfrogs when we go for country walks across meadows
and through orchards, even though the meadows and orchards
may be near ponds or lakes. We are more likely to see them if
we go rowing on river or pond. The Bullfrog is more thoroughly
1 Solitary individuals may remain active throughout the winter, in spring houses or large
springs, in the vicinity of Philadelphia.
228
THH FROG BOOK-
PLATE LXXXVII
FIG. 275.— Under the pickerel weed. The BULLFROG is the most aquatic frog of Northeastern North America.
\_Rana catesbiaiia Shaw. Rhode Island.]
THE FROG BOOK
PLATE LXXXYTTT
June— We are likely to hear and see BULLFROGS if \ve go rowing on river or pond.
-*^
BULLFROGS prefer large ponds where the water is screened from the shore by willow, alder and other
water-loving plants.
The Common Bullfrog
aquatic than any of the other frogs of northeastern North Amer-
ica. However, if we happen to be walking across country, or
even along a country road during a long-continued heavy rain,
we may overtake a large Bullfrog who seems to be making the
same journey. Whether the continued wet weather has tempted
him to go hunting beyond his usual bounds, or whether he is mi-
grating from pond to pond, it would be difficult to say. He
proceeds by successive leaps, about three feet each in length.
He can cover a distance of five or six feet without difficulty,
notwithstanding his large, heavy body. A wet Bullfrog leaping
across a dry surface leaves curious tracks, interesting in that
they show how large a part of the under portion of the body
and thighs strikes the ground forcibly after each leap, and how
the frog " toes in " with its front feet.
The Bullfrog is our largest frog. (Fig. 277.) He may
measure six or seven inches from the tip of the muzzle to the
posterior end of the body. A young frog of this species, which
had been raised in the laboratory, measured four inches in length
on his first birthday. However, size is not a good criterion by
which to judge the age of a Bullfrog, or even its identity. The
variation in this particular is marvellous. A frog one year old
may be no more than two inches long. Much depends on the
size attained by the tadpole before the transformation, and of
course much also depends on the food and other conditions
of the environment, and the ability of the individual frog to cope
with these conditions.
The Bullfrog (Figs. 276 to 278) is very easily distinguished
from other frogs, however, whatever may be its size. The head
is broad and flat. (The head of the young Bullfrog is relatively
less broad than that of the adult.) The ear is much larger than
the eye. There are no lateral folds. There is a short fold of
skin extending backward from the eye, over the ear, and down
229
Ranidae
to the shoulder. The hind feet are fully webbed. (Figs. 281
and 282.)
The colour varies greatly, not only according to the sex,
but also among individuals of the same sex. The Bullfrog
has power to change colour considerably. The general colour
of the upper parts is dull olive-green, marked with irregular,
dusky spots of brown. However, when the frog is in warm air,
and exposed to bright light, the skin may become a beautiful
spotless yellow-green, very light in tone. The Bullfrog just
from the mud, or from some place of concealment in deep water,
is so dark-coloured that he is nearly black. Experiments prove
that light has much to do with these changes of colour; at least,
that these changes in colour take place with changes of light,
when temperature and moisture conditions remain the same.1
The female is usually more brown and spotted, and the
male more nearly plain green. The under parts of both are
white, with distinct or indistinct mottlings of brown. The
male has a bright yellow throat; that of the female is dirty
white, mottled with brown. The ear of the male is much larger
than that of the female.
This description holds regarding the Bullfrog of north-
eastern North America. In southern New York, and still
farther south, the Bullfrog is more likely to be spotted, and
the male lacks the bright yellow on the throat. The Bullfrog
of Texas has the underparts vividly marked everywhere with
irregular, connected black spots. This frog of the Southwest
has also a more tubercular and leathery skin. There are prob-
ably three or four distinct varieties of this species in different
localities of North America. It is certain that the Bullfrog
of Wisconsin and adjoining regions is different enough to be
classified as a variety. (Fig. 278.) It is finely spotted with
dark on all parts except the head. There is much more bright
yellow in its colouration than in that of Bullfrogs from other parts
of North America. The male has this colour not only on the
throat, as in the case of the Eastern Bullfrog, but also along
the sides of the body and on the legs and feet to the tips of the
toes. The head is relatively more pointed than that of other
Bullfrogs. The body is relatively longer; the head is contained
1 See pp. 22 to 27 for discussion of change of colour in the Batrachia.
230
The Common Bullfrog
three and one-fourth to three and one-half times in the total
length, whereas the usual proportion is one to three. The eyes are
surprisingly small and little elevated, giving the flat head an
expression greatly lacking in intelligence and alertness. The
longitudinal diameter of the eye in a frog 6£ inches long is a
short f inch, while it is fully £ inch in an Eastern Bullfrog meas-
uring 5 f inches. The smaller size of the eye results in a greater
space between the eye and the nostril and a longer fold of skin
above the ear. In this frog the vocal sacs of the throat extend
backward over the arm so that when the frog croaks, not only
does the throat swell, but pouches appear between the ear and
the arm as in the case of the Leopard Frog. The increase in vocal
powers in this frog is shown also in the fact that the female croaks
in a manner similar to that of the male, but without quite the
same force and without the appearance of pouches at the sides
of the head.
The Common Bullfrog is a powerful swimmer, with great
strength and length of hind legs (which may measure from
seven to ten inches long) and with very large webs. It is inter-
esting to see one dive under the water. The legs are straight-
ened powerfully, and then slowly drawn forward into position
for the second stroke. The huge web is alternately extended
into a flat resisting membrane and folded again as the leg is
drawn forward. The eyes are shut; that is, they are flattened
until they are level with the head, by being lowered in their
sockets, which project downward from the roof of the mouth.
(Fig. 279.) This takes the eyes out of danger during the swift
motion through the water, but also makes it necessary that the
frog shall swim rapidly but a short distance at a time. He must
stop, or slacken speed and open his eyes to see where he is,
and then, perhaps, may make a new plunge with eyes lowered, if
an enemy is near. The frog, like the toad, has no outer ear to
hinder him in swimming. The ear-drum is at the surface of the
head, covered and protected merely by the moist skin.
Something else is seen to take place, also, as the frog dives
under water. Large bubbles of air are given off from the nostrils,
which are then closed tightly. The frog does not use the lungs
in breathing under water; the nostrils are kept closed, and the
throat shows none of the swallowing movements so conspicuous
when the frog is breathing air. The frog's moist skin is like a
231
Ranidae
great gill stretched over the whole body. In consequence the
frog not only can live under the water for months at a time, but
will, by preference, spend a very large portion of his time lying,
with flattened body and closed nostrils, at the bottom of the
pond.
If we go rowing on river, lake, or park lagoon some moon-
light night in late June, we are certain to hear the deep-toned
call of the Bullfrog many times. Coming as it does at unex-
pected intervals and from unexpected directions, it seems
startlingly weird in the quiet of the night. For June nights are
quiet. The insect orchestras are not yet in full swing and the
frog choruses have disbanded. The toads are still calling, though
much more feebly than earlier in the season, and the voices of
only a few can be heard, whereas there were hundreds in May.
The Bullfrog does not sing in chorus; the call is an isolated one.
The notes are so low in pitch that we think of him as the bass
viol among the batrachia. The call resembles, to a consider-
able degree, the roar of a distant bull, but it has a more musi-
cal ring, and the notes are less blended and slurred. The pitch
varies with the individual. The following are four interesting
annotations of the bullfrog's call:1
The call can be imitated well by saying with a hoarse, deep-
toned voice the syllables of various interpretations of it, such
as, " Be drowned," " Better go round," " Jug o' rum," or " More
rum." The imitation is especially good if the slurred words
are repeated in front of some reverberating hollow body. That
the call has a musical quality was once illustrated most ludic-
rously. During the rehearsal of a chorus of female voices, a
big yellow-throated Bullfrog, in an adjoining room, began vig-
orously ejaculating, " Jug o' rum, jug o' rum, jug o' rum."
Several persons were deceived for the moment into thinking
that the bass voice of the director had joined the chorus, for it
happened that the first few notes of the frog were in time and
harmony with the chords of the selection. A tame Bullfrog
1 Familiar Life in Field and Forest. F. Schuyler Matthews. D. Appleton & Co.
232
X
X
X
X
hJ
o
o
co
o
o
S
h
THE FROG BOOK
FIG. 278.— The BULLFROG (Rana catesbiana Shaw) is heard in the ponds by the first of May. Oshkosh, Wiscon-
sin. (See page 230.)
The Common Bullfrog
will always sing when other sounds are being produced, whether
these are musical or not. He always becomes enthusiastic at
the sound of running water.
The Bullfrog has two internal vocal sacs, which act as
resonators. These are in the pouch of the throat, and the open-
ings into them are on the floor of the mouth. (See Fig. 279.)
When the frog croaks, the yellow throat over the vocal sacs,
and the sides of the body in the region of the lungs, are forcibly
distended with air drawn in through the nostrils. Throat and
sides immediately relax as the air passes out over the vocal
cords of the throat and the sound is produced.
The frog's vocal powers do not stop with the croaking de-
scribed. If we live in the country, or if we are given to camping
and fishing, it is possible that at least once in a lifetime we shall
hear this species of frog give voice to quite another sound. This
comes when he is forcibly seized by a huge enemy, such as a hawk
or an otter. The unexpected sound given at such a time is most
distressing to hear. It is a loud, prolonged, high-pitched scream,
containing anguish and antagonism, to such an extent that we
cannot but think that the cry is made by the human voice.
Sometimes, when we take into our hands a masterful, untamed
Bullfrog, just brought from the pond, he gives this same cry
with wide-opened mouth. The scream of distress is so penetrat-
ing, and so prolonged, that we hasten to release the frog, for
fear our neighbours will accuse us of cruelty to children.
However, as the mouth is held wide open while the cry is
given, we find a most excellent opportunity to see various things
about which we may have been curious. (Fig. 279.) The
tongue has a forked posterior end, and has its front end fastened
just back of the lower lip.1 There is a circle of small, sharp
teeth on the upper jaw. Two large openings at the sides back
of the tongue lead into the vocal sacs. Two smaller openings
on the roof of the mouth are the openings of the tubes leading
from the nostrils. Their situation so far in front of the throat
makes it clear why it is that the frog must swallow the air that
passes in at the nostrils in order to get it down to the lungs.
The great rounded elevations on the roof of the mouth are made
by the eyes. These extensions from the roof of the mouth
1 See description of toad's tongue, p. 81.
233
Ranidae
appear when the eyes are flattened to a level with the top of the
head.
The Bullfrog feeds upon the insects and other small life
of the pond, as has been stated. But this does not make up the
greater part of his food. He is the green dragon of the pond
to the fish, the small turtles, the young water-birds, and, alas,
to the frogs also. The Bullfrog will eat any moving object
that he can swallow or partially swallow. It does not take long
to find out the cannibalistic traits of this frog, and to learn that
we must not keep a large specimen in the same place with smaller
frogs. When we open the collecting-pail on arriving home
from a trip to the pond, we learn our lesson, for several of the
smallest frogs have disappeared, and the feet and legs of one of
the largest are protruding from the capacious mouth of the big
fellow.
The Bullfrogs are found throughout the United States, east
of the Rocky Mountains. They are less common than many
other frogs. This is not entirely owing to the many enemies
of the adults, i. e. snakes, otters, hawks and owls, herons, turtles,
and (at the South) alligators. Nor is it wholly due to the fact
that the tadpoles and the young frogs are preyed upon by fish
and by all sorts of small enemies of the pond — to say nothing
of their own greedy kin. It is probably due in some measure to
the fact that their large size has made them especially valuable
as food for man, and that their large size, together with their
greed, has made them easy of capture. They bring a price of
from one to four dollars per dozen at the markets.1
The Bullfrog is solitary in habit, except at the breeding-
season. This breeding-season is late, extending from the last
of May into July. The tadpoles do not develop into frogs during
the first season, as do those of the Leopard and Pickerel frogs.
It is not until the second season, and sometimes the third, that
a Bullfrog tadpole makes its final transformation.2 Giant
Bullfrog tadpoles can be found any month in the year. It is
'Frog hunting is carried on in all parts of the United States. The states supplying the
largest amounts for the market are New York, Maryland, Virginia, Indiana, Ohio, Alissouri and
California This work yields $50.000 annually to the hunters, but threatens the practical ex-
tinction of our native frogs. It has been demonstrated on Frog Reserves or "Frog Farms" in
Wisconsin, California and elsewhere that frog raising is a practicable and profitable industry. (See
Notes on the Edible Frogs of the U. S. Extract from Report of 1897 of the Commissioner of
U. S. Fisheries)
2 This fact is interesting to persons actually concerned in frog culture.
234
THE FROG BOOK
PLATE XCI
Teeth
Vomer with
Teeth
Opening
to Larynx
andLuncjs --
Internal nostril
Openings
Elevation Caused
bu Eye ball
Opening of
the EustachianTube
from Ear
Openino into
Vocal Sac
-T.
on
The Arms
develop
within the
Gill
Chambers
Exit from
Left Gill
Chamber
"Narrow Canal
Connecting
and left-
Gill Chambers
FIG. 279. — Drawing to show the floor and the roof of the Bullfrog's mouth.
FIG. 280. — BULLFROG TADPOLE, one day previous to the time of activity of the arms. Drawn to show the connec-
tion of the gill chambers. (This canal lies directly in front of the heart.) [Enlarged.]
w
XI
XI
•;'£.
CYSTIGNATHID.-E, 7, 9, 14, 43, 45t 163-165.
Development, 3-5.
frog's egg, 176-181.
toad's egg, 67-71.
Dipnoi, 12.
DISCOGLOSSID.«, 5, 7, 8, 14, 26, 43, 51-53.
Distribution, 35-42.
Ears of Salientia, 6, 31, 77, 231, 238.
Eastern Wood Frog, see Rana sylvatica.
Economic value, 80-86, 185, 234.
Efts, 21.
Eggs of Salientia, description, 3-4.
development 67-71, 176-181.
enemies of, 4.
Enemies of eggs, 4.
of tadpoles, 146, 181-183.
of toads and frogs, 72, 215, 234.
Engystoma carolinense, n, 19, 21, 40, 48,
166—168.
' texense, 48, 168-169.
ENGYSTOMATID.E, 8, 10, 43, 48, 166-170.
Families of Salientia, 7.
Firmisternia, 8,
Fishes, i, 6.
Flash colours, 26.
Florida Tree Frog, see Hyla gratiosa.
Food of frogs, 28, 184, 190, 196, 202-203 '
214, 228, 238, 239.
of tadpoles, 69, 210, 235.
of toads, 29, 90, 8 1-86.
Fossils, see Phylogeny.
Fowler's Toad, see Bufo fowleri.
Frogs, see RANID.E.
Geographical Distribution, 35-42, 52, 134,
251
Index
Gill chambers, 236, 237.
Gills, 14, 68, 69, 179-181, 236, 237-
Gopher Frog, see Rana czsopus.
Grass Frog, see Rana pipiens.
Green Frog, see Rana clamitans.
Green Tree Frog, see Hyla cinerea.
Hermit spadefoot, see Scaphiopus holbrookii.
Hibernation, 15, 33, 88.
Hyla andersonii, 26, 38, 46, 131-133.
arenicolor, 41, 46, 122-124.
carolinensis, see cinerea.
cinerea, 24, 40, 47, 126-128.
evittata, 38, 47, 128-130.
jemoralis, 47, 150-151.
gratiosa, 24, 27, 46, 124-126.
fickeringii, 4, 20, 21, 24, 38, 46, 138-
148, 139-142 (voice), 143-144 (col-
our), 145-147 (life history).
regilla, 4, 24, 26, 41, 47, 134-138.
squirella, 24, 47, 148-150.
versicolor, 24, 27, 38, 46, 117-122, 119
(colour), 120 (protection), 121-122
(life history).
v. ph&ocrypta, 120.
Hyla of the Pine Woods, see Hyla femorahs.
HYLID^E,?, 9, 14, 19, 26, 39, 43. 46, n7~
162.
Hypopachus cuneus, 19, 48, 169-170.
Inhibition, 31.
Intelligence, 34.
Interference cells, 25.
Key to BUFONID^E, 44.
CYSTIGNATHIDJE, 45.
ENGYSTOMATID^B, 48.
FAMILIES, 43.
HYLID;E, 46.
PELOBATID/E, 43.
RANID^:, 48.
Labyrinth tests, 29.
Lachrymal canal, 5.
Larva, see tadpole.
Lateral line sense organs, 6.
Leeches, 4.
Leopard Frog, Common, see Rana pipiens.
Southern, see Rana sphenocephala.
Life History, 3~7 (general), 55-56 (S. hol-
brookii'), 67-73 (B. americanus), 96
(B. fowleri), 121-122 (H. versicolor),
137-138 (H. regilla), 145-148 (H.
•pickeringii), 156 (Acris gryllus), 159-
160 (Chorophilus nigritus), 175-185
(R. pipiens), 191-192 (R. palustns),
204-205 (R. clamitans), 208-2 io( R.
sylvatica), 219 (R. pretiosa), 225 (R.
septentrionalis), 234-238 (R. cates-
biana).
Linnseus, 1 1 .
Literature, 76-77 (footnote),
Lithodytes latrans, 39, 40, 46, 163-164.
ricordii, 46, 164.
Merriam's Life Zones, 37~38.
Metamorphosis, 5-7, 69-71, 204-205, 235-
238.
Mink Frog, see Rana septentrionalis.
Moulting skin, 73 (Bn{o americanus), 201
(Rana clamitans).
Mouth structure of tadpoles 69 (B. ameri-
canus), 97 (B. fowleri), 121 (H. ver-
sicolor), 146 (H. pickerinii), 156,
(Acris gryllus), 160 (Chorophilus), 181
(R. pipiens), 191 (R. palustris), 210
(R. sylvatica), 235 (R. catesbiana).
Mouth structure of toads and frogs, 81,
233-
Mud puppy, 2.
Narrow-mouthed Toads, see ENGYSTO-
MATID.E.
Necturus, 3.
Neotropical Region, 37.
Newts, 2.
Nocturnal habit, 83.
Northern Frog, see Rana septentrionalis.
Northern Wood Frog, see Rana cantabri-
gensis.
Oak Toad, see Bufo quercicus.
Opercular membrane, 6, 14, 68, 70, 181, 237.
Orientation, 32.
Pacific Tree Frog, see Hyla regilla.
Pain scream, 32, 233.
Peeping Frog, see Hyla pickeringii.
PELOBATID/E, 4, 5, 7, 14, 26, 43, 53-62.
Pentadactyle limbs, i, 13.
Phototactic, 32.
Phylogeny, 11-15.
Pickerel Frog, see Rana palustris.
Pickering's Hyla, see Hyla picker ingii.
Pigment cells, 22-23.
"Playing dead," 34, 71, 87.
Poison, 1 6- 1 8, 79-80.
Pond Frog, see Rana clamitans.
Proreptilia, 12.
Protection, 17, 33, 34, 86-88, 120, 130, 138,
219.
Protective resemblance, 27, 34, 87, 120;
Figs. 61, 81, 134, 137, 212, 239.
Rain of Toads, 71.
Rana assopus, 17, 20, 49, 193-196.
areolata, 20, 40, 49, 192-193.
areolata assopits, see cesopus.
areolata capita, see areolata.
areolata circulosa, see areolata.
aurora, 26, 41, 49, 216-218.
boylii, 41, 50, 221-222.
cantabrigensis, 38, 49, 211-213.
cantabrigensis latiremis, n, 38, 212.
catesbiana, 3, 18, 20, 21, 26, 27, 50,
196, 227-240, 228 and 234 (food), 230
(colour change), 231 (swimming),
231-232 (respiration), 232-233
(voice), 233 (mouth structure), 234
(economic value), 234-2 38 (metamor-
phosis), 236-238 (breathing of tad-
pole).
clamata, see clamitans.
clamitans, 38,49, 197, 198-205,198-200,
(voice), 200-201 (comparison with
Bullfrog), 201 (moulting), 202-203
(food), 204, (eggs), 204-205 (meta-
morphosis).
draytonii, 4, 26, 41, 49, 213-216.
draytonii onca, see onca.
fisheri, see onca.
grylio, 20, 26, 27, 50, 226-227.
onca, 27, 49, 196-198.
palustris, 26, 38, 48, 188-192, 190
(food), 191-192 (life history).
pipiens, 4, 5, 20, 27, 38, 40, 41, 49,
171-185, 172 (vocal pouches), 173
(breathing), 174 (colour), 175 (moult-
ing), 175-176 (eggs), 176-181 (de-
velopment), 181 (mouth structure
of tadpole), 181-184 (enemies of
tadpole), 185 (economic value),
:87.
pretiosa, 4, 26, 41, 49, 218-221.
septentrionalis, 50, 224-226.
252
Index
Rana sphenocephala, 20, 48 186-188.
sylvatica, 3, 4, 18, 26, 38, 49, 205-211,
208-210 (development), 208-209
(voice), 211 (colour change).
virescens, see pipiens.
virescens brachycephala, see pipiens.
virescens sphenocephala, see sphenoce-
phala.
virgatipes, 20, 26, 38, 50, 222-224.
RANID^;, 8, n, 26, 43, 48, 171-240.
Regeneration, 18, 236.
Respiration of adult, 70, 76, 231, 233, 237.
of tadpole, 5, 8, 14, 68-69, 70, 179-181
236, 237.
Rocky Mountain Toad, see Bufo 1.
Salamanders, see URODELA.
Salientia, animal behaviour, 27-35.
Classification, 7.
Colour of, 22-27.
Development and metamorphosis,
3-7-
Distribution, 35-42.
Hibernation, 15-16.
Phylogeny, 13.
Poison, 16-18.
Regeneration, 18.
Songs of, 18-22.
Salt-marsh Frog, see Rana pipiens.
Scaphiopus couchii, 41, 44, 57-59.
Iiammcrtidii, 41, 44, 59-60.
h. bombifrons, 40, 44, 61-62
holbrookii 4, 38, 43, 53-57. 55 (call),
55-56 (life history).
Screaming Frog, 198 (see Rana damitans).
Skeletons of Batrachia, i.
of Fishes, i.
of Reptiles, 2.
of Salientia, 2.
of Urodela, 2.
Skin absorption _of water, 78, 90.
Smilisca baudinii, 27, 40, 46, 151-153.
Snakes, 72.
Sonoran Subregion, 39.
Southern Bullfrog, see Rana grylio.
Southern Leopard Frog, see Rana sphenoce-
phala.
Southern Spadefoot, see Scaphiopus couchii.
Southern Toad, see Bufo lentiginosus
Southern Tree Frog, see Hyla squirella.
Spadefoot of the Western Plains, see Scaphio-
pus h. bcmibifrons.
Spadefoot Toads, see PELOBATIDCE.
Spea, see Scaphiopus.
Special senses, hearing, 30, 32.
lateral line, 6.
Special senses, sight, 30, 32.
touch, 28, 29, 34.
_ taste, 28, 90.
Spring Frog, see Rana damitans.
Spring Peeper, see Hyla pickeringii.
Statistics on food of toad, 83-86.
Stegocephali, 12, 13.
Stejneger, Dr. Leonhard, 52, m, 157.
Striped Frog, see Rana virgatipes.
Suckers," 68, 179.
Swamp Tree Frog, see Chorophilus nigritus
Syrrophus marnockii, 39, 40, 45, 165.
Tadpole, development, 67-71, 176-181.
enemies of, 146, 181-183.
food of, 69, 210, 235.
lateral line sense organs, 6.
metamorphosis, 5-6, 69-70, 235-238.
mouth structure, 69, 181, 235.
regeneration of tail, 18, 236.
respiration, 5, 8, 14, 68-69, ?o, 179-
181, 236, 237.
suckers, 68, 179.
Tailless Batrachia, see Salientia.
Temperature, 4, 6, 15-16, 23, 28, 33.
Tongue of Toad, 81 (Fig.Sg).
Toads, see BUFONID/E.
Tree Frogs, see HYLID/E.
Tree Toad, see Hyla versicolor.
Triton, 2.
Urodela, 2, 5, 13, 147, 209.
Vocal Pouches, External, 19, 75, 95, 101
.. , J°3, 172, 188, 195.
Vocal bacs, 19, 75, 233.
Voice among Salientia, 18-22 (general),
95-96 (B. fowleri), 64, 66, 75, (B.
americanus), 91 (B. lentiginosus), 101
(B. cognatus), 103 (B. compactilis),
105 (B. quercicus), ng(H. versicolor),
123 (H. aremcolor), 128 (H. cinerea),
T.3o(H.evittata), 133 (H. andersonii),
138 (H. regilla), 139-143 (H. picker-
wgii), 155 (Acris), 164 (Lithodvtes),
167 (Engystoma), 173 (R. pipiens),
189 (R. palustris), 198-200 (R. dami-
tans), 209 (R. sylvatica), 232 (R.
catesb^ana).
Warts, 1 8, 80.
Water Dog, 2.
Western Frog, see Rana pretiosa.
Western Spadefoot, see Scaphiopus ham-
mondii.
Wood Frog, see Rana sylvatica.
253