The chapter on “The Development of the Alligator” is a reprint, with slight alterations, of the paper of that title published for the author by the Smithsonian Institution.

The bibliography, while not complete, will be found to contain most of the important works dealing with this group of reptiles.

The author is grateful to Mr. Raymond L. Ditmars and to his publishers, Messrs. Doubleday, Page & Co., and Messrs. Sturgis & Walton, for the use of a number of plates; to the Macmillan Company and to the United States Bureau of Fish and Fisheries for the same privilege; to the National Museum for photographs of the skull of the gavial; and to the Smithsonian Institution for the use of the plates from researches published by them and included herein.

Proper acknowledgment is made, under each borrowed figure, to the author from whom it is taken.

Morgantown, W. Va.
May 1, 1915.

CONTENTS

PAGE
CHAPTER I
The Biology of the Crocodilia[1]
CHAPTER II
The Skeleton[46]
CHAPTER III
The Muscles[90]
CHAPTER IV
The Nervous System[131]
CHAPTER V
The Digestive System[150]
CHAPTER VI
The Urogenital System[192]
CHAPTER VII
The Respiratory System[197]
CHAPTER VIII
The Vascular System[201]
CHAPTER IX
The Development of the Alligator[226]
Bibliography[343]
Index[349]

ILLUSTRATIONS

PAGE
Alligator Mississippiensis. (In color.)[Frontispiece]
FIGURE
[A].Skull of Belodon5
[1].Map Showing the Present Distribution of Crocodilia6
[2].Heads of American Alligator and CrocodileFacing 7
[3].Alligator Joe in the EvergladesFacing 10
[4].Alligator Hunter in the OkefinokeeFacing 10
[5].Nest of C. PorosusFacing 21
[6].Jackson SloughFacing 21
[7].A Typical Alligator HoleFacing 23
[8].Alligator Nest, Made Chiefly of GrassFacing 25
[9].Alligator Nest, Made Chiefly of FlagsFacing 27
[10].Two Species of Caiman: Broad-Nosed Caiman,Spectacled CaimanFacing 35
[11].Two African Crocodiles: Nile Crocodile,West African CrocodileFacing 39
[12].Salt Water CrocodileFacing 41
[13].Skull of Gavial, Ventral ViewFacing 43
[14].Skull of Gavial, Lateral ViewFacing 43
[15].Alligator SkinsFacing 46
[16].Entire Skeleton of Crocodile50
[17].First Four Cervical Vertebræ of Crocodile52
[18].Thoracic and Sacral Vertebræ of Crocodile55
[19].Dorsal View of Skull of AlligatorFacing 60
[20].Ventral View of Skull of AlligatorFacing 63
[20A].Longitudinal Section of Tooth of CrocodileFacing 66
[21].Lateral View of Skull of Alligator69
[22].Posterior View of Skull of AlligatorFacing 70
[23].Sagittal Section of the Skull of Alligator71
[24].Dorsal View of Lower Jaw of AlligatorFacing 74
[25].The Hyoid Apparatus77
[26].The Sternum and the Associated Membrane Bones79
[27].The Pectoral Girdle and Anterior Limb82
[28].The Pelvis and Sacrum85
[29].The Posterior Limb87
[I].Plate I. The Shoulder MusclesFollowing 130
[II].Plate II. The Muscles of the Anterior RegionFollowing 130
[III].Plate III. The Muscles of the Posterior RegionFollowing 130
[IV].Plate IV. The Muscles of the Posterior RegionFollowing 130
[V].Plate V. The Muscles of the Posterior RegionFollowing 130
[30].The Brain of the AlligatorFacing 132
[31].The Brachial Plexus of C. Acutus140
[32].The Crural Plexus of A. Mississippiensis142
[33].Interior of the Mouth of the AlligatorFacing 151
[34].The Digestive System of the Alligator152
[35].Outline of the Digestive Tract of the Alligator158
[36].Covering of the Anterior Region of the Tongue160
[37].Covering of the Posterior Region of the Tongue161
[38].Gland from the Posterior Region of the Tongue162
[39].Gland from the Posterior Region of the Tongue164
[40].Covering of the Roof of the Mouth166
[41].Transsection of the Anterior Region of the Œsophagus169
[42].Transsection of the Posterior Region of the Œsophagus170
[43].Epithelium of Anterior Region of Œsophagus172
[44].Epithelium of Anterior Region of Œsophagus173
[45].Transsection of Wall of Pyloric Stomach176
[46].Glands of Fundus of Stomach177
[47].Transsection of Wall of Anterior Region of Small Intestine181
[48].Transsection of Wall of Middle Region of Small Intestine182
[49].Transsection of Wall of Posterior Region of Small Intestine183
[50].Mucosa of the Anterior Region of Small Intestine184
[51].Transsection of the Wall of the Middle Region of the Small Intestine185
[52].Transsection of the Wall of the Anterior Region of the Rectum186
[53].Epithelium of the Anterior Region of the Rectum187
[54].Female Urogenital System of Alligator193
[55].Male Urogenital System of AlligatorFacing 195
[56].Male Organ of AlligatorFacing 195
[57].Respiratory Organs of Alligator198
[58].Heart of AlligatorFacing 202
[59].Veins of the Posterior Region of Alligator204
[60].Veins of the Anterior Region of the Alligator209
[61].Arteries of the Posterior Region of the Alligator213
[62].Arteries of the Anterior Region of the Alligator215
[VI].-[XXVIII].Plates VI to XXVIII. A Series of Figures to Illustrate the Development of the American AlligatorFollowing 342

THE ALLIGATOR AND
ITS ALLIES