CONTENTS ix 

 PART II. ANIMAL BIOLOGY 



CHAPTER PAGE 



I. INTRODUCTION i 



II. PROTOZOANS 10 



III. SPONGES 17 



IV. POLYPS 22 



V. ECHINODERMS 34 



VI. WORMS 42 



VII. CRUSTACEANS . . . . , . . . .51 



VIII. INSECTS 63 



IX. MOLLUSKS 97 



X. FISHES .......... 109 



XI. BATRACHIANS 126 



XII. REPTILES 139 



XIII. BIRDS 150 



XIV. MAMMALS 184 



PART III. HUMAN BIOLOGY 



I. INTRODUCTION i 



II. THE SKIN AND KIDNEYS 16 



III. THE SKELETON 29 



IV. THE MUSCLES 39 



V. THE CIRCULATION 51 



VI. THE RESPIRATION .70 



VII. FOOD AND DIGESTION 89 



VIII. THE NERVOUS SYSTEM 117 



IX. THE SENSES ......... 142 



X. BACTERIA AND SANITATION .158 



GENERAL INDEX i 



