I ' 



CONTENTS. 



PAGE 



PREFACE v 



I. GENERAL INTRODUCTION. 



1. THE POSITION OF MAMMALS IN THE ANIMAL KINGDOM . . 1 



2. PHENOMENA OF CONVEBGENCE 14 



3. THE DISTINCTIVE CHARACTERISTICS OF MAMMALS . . . 30 



4. THE EXTENSION OF PAL^IONTOLOGICAL SCIENCE SINCE 



CUVIER 45 



5. THE STRATA OF THE TERTIARY FORMATION . . . . 77 



II. SPECIAL COMPARISON OF THE LIVING 

 MAMMALS AND THEIR ANCESTORS. 



1. THE MONOTREMA, CLOACAL OR FORKED ANIMALS . . 86 



2. THE MARSUPIALS 93 



3. THE EDENTATA, OR ANIMALS POOR IN TEETH . . .110 



4. THE UNGULATA, OR HOOFED ANIMALS . . . . . 126 



PAIR-HOOFED ANIMALS. 



1. The Suidffi, or Pigs 137 



2. The Hippopotamus, or Eiver Horse . . , . 144 



3. The Buminants 150 



4. Camels . . 154 



5. Deer and their Kindred Forms .... 158 



6. Hollow-horned Animals, Antelopes and Oxen . . 173 



