o{ I! CT m tr r- O m 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 6 in c « I V V u o 'rt u _o V V « u •5 c o •c u | 5 « o v •o ^- O w b Rj c •o V S J* c. Id X L> Q_ d o \2" IP o id E 3 3- O O -o c — O 1 & 1 i <*=? 1 == 1 =^-~« 1 i O O M O O a; d, w a H E D C 0> in (D c "o u "5 l-t U 'o 5 •*" oi 'c u U l- u u tn — !< 1) 2 § 3 S in o O « w -a g« > rt 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- s S s. I 13 °-% o s C — "~ — u «» .5 2 ** o w \ '"f. -3 IT : "3 . 2 JJ. C — 3 B a o o re u o a u. Scaphiopus Couchii 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 X t-H III < J ft. irf o o CQ O o a. ta •' 8 a o. > o £ o "or) O •3 I a o 4-» O t O a uT £: THE TOADS1 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 al o o o o a; fc a o 3 B C O u o 03 .a u £ 3 O •a o a u J2 c M U 1) O X £ •= U) w cfl O I H. l*_ X : J I c § N j 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. X a a. HI .e -s tu « -^ c I/I lli o c — ._ o « 3 ~ cd -5 s u o a. C Ui 3 O a. >, rt B .JO D. C. O £ a z H u 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 X X I •o c IP P en 1; CQ •£ -a « <5 II u: o o ec o o K u. •e K o s d. Q O H O (fi u 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. x h < _1 a. xl II a! U, u H • • Fowler's Toad 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 94 x X a H O O oa u O X X III H < J fr. O o M o a; fc w K a (S G Hi ^^ 5-d SI T3 o c a ed « " "Si M £H S E I > ?i fcjo~ .5 -' V V s -a •o a 2 "2 S u X) > O •o rt o -3 T3 I/} "o u U5 J5 .H CM « 5 o O 2 ^ rt o> § ™ C _ „ o o " . fe *° o «•! U . w O O X w a u s ~ ** *v',y^ tf p 5- 2 c' e vj "^* r~) %1 Vj w r * "^ ^2 •2.S. O «) «*> i ^ = 1. S 1. -a '-' T3 C4 5J <^^ O^' C. a fi U - 2 2 « (i, on fc i- rrt •O S 0! d. 1) cx j: « D3 o o £ di i "8 3. rt u be o o U _a; 5 « tn S H 5 .S IS o T 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. IO2 X y, y. a h o o M O O a x £-< rt bfl c O a a 3 -a 2 O o " o £ t- ca -a .£ 2 « > .~ -o to 2 jl tE i- o £ x y, X w h x .0 >, °2 '5 o V J= W 3 O T3 1) cd \ « HI J3 C o! U l_i U •o Ul CIS — _2 X S u ~ ! H o iT o u. 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 X X X H H .0 HI o jr o c M C o o: fc _;; •j u o> 3 a a •a a u O I a f, THE FROG BOOK PLATK XXXV11I 4 r*. \ 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 X X X X w 'A o - — Id H <-; c II o 2 ° - _o M HI 1-1 c/3 - £ 2 = i " V I O o M O O u h •o 3 t/3 H aJ C 2 K I 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 a. 2 M O O . M cd o II * a . u .2 2 2 rt i- .fi £ ° IS C - a S - ^= O ^. 2 rt rt CJ 11 'w 3 C H II * 5 = .2 £ o S 0 c, . . "5 £ in X rt — I) O - u I) rt ~ ^2 '> -a in rt C cu > « ca - X -t- c o W •- £ b a . w a o III o >, < 8 S sc c . - I. § a i 2 s •3 5 a> 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 1 80 u h 01 rt s 0) "3 CT •5 So l- C he u. _ rt - 3 C « O rt o i 3 n "O «T o .S CU en 01 . b£ §1 OH ^* o 2 U M 1 £ ^J , JJ W H J 8| Q '5) o pa c c £ K 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. . X X J u 0 c 33 o u. U. I E- o U O O OS b J ui O o OS a as id W U U X 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 O O M 0 O a. U. w - — ^ •s cd = o s > -y. s — -3 5 il « 2 = S S 3 - - ^ 3 t •C . co -; S3 I I/I THE FROG BOOK PLATE LXXIV FK.S. 22610 22S.— A'tfHns 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