CONTENTS 



CHAPTER I 



PAGE 



ONTOGENY 1 



CHAPTER II 



THE CELL AND CELL DIVISION 31 



CHAPTER III 



THE GERM CELLS AND THEIR FORMATION 85 



CHAPTER IV 

 MATURATION 131 



CHAPTER V 

 FERTILIZATION 164 



CHAPTER VI 



CLEAVAGE 219 



CHAPTER VII 



THE GERM CELLS AND THE PROCESSES OF DIFFERENTIATION, HEREDITY, 



AND SEX DETERMINATION 260 



CHAPTER VIII 



THE BLASTULA, GASTRULA, AND GERM LAYERS. MORPHOGENETIC 



PROCESSES 329 



INDEX . 367 



