x Contents 



CHAPTER VII 



PAGE 



Regeneration 153 



CHAPTER VIII 



Determination of Sex, Secondary Sexual 

 Characters, and Sexual Instincts: 

 I. — The Cytological Basis of Sex Deter- 

 mination 198 



II. — The Physiological Basis of Sex De- 

 termination 214 



CHAPTER IX 

 Mendelian Heredity and its Mechanism . .229 



CHAPTER X 



Animal Instincts and Tropisms . . . 253 



CHAPTER XI 

 The Influence of Environment . . . 286 



CHAPTER XII 



Adaptation to Environment . . . .318 

 CHAPTER XIII 



Evolution 346 



chapter xiv 

 Death and Dissolution of the Organism . 349 



Index 371 



