x CONTENTS 



Page 



CHAPTER XII 

 Ontogeny 237 



CHAPTER XIII 

 Heredity 262 



CHAPTER XIV 

 Evolution 290 



CHAPTER XV 

 Adaptation 324 



CHAPTER XVI 

 Environment and Distribution 359 



CHAPTER XVII 

 The Animal Kingdom 367 



References 459 



Glossary 463 



Index 477 



