x CONTENTS 



PART III 

 DEVELOPMENT AND LIFE-HISTORIES 



CHAPTER XIV 



THE CONTINUANCE OF LIFE 



1. Modes of reproduction 2. The evolution of sex 3. Divergent 

 modes of reproduction 4. Historical 5. The egg-cell or ovum 

 6. The male-cell or spermatozoon 7. Maturation 8. Fer- 

 tilisation . . pp. 298-312 



CHAPTER XV 



DEVELOPMENT 



1. Segmentation and after 2. Differentiation 3. Some generalisa- 

 tions : (a) The ovum theory ; (6) the gastraea theory ; (c) 

 recapitulation; (d) organic continuity . . pp. 313-322 



CHAPTER XVI 



LIFE-HISTORIES 



1. The curve of life 2. Larval periods 3. Prolonged embryonic 

 life 4. Intricate life-histories 5. Prolonged youth 6. Ado- 

 lescence 7. Senescence and rejuvenescence 8. Death 9. 

 Retrospect ... . pp. 323-337 



PART IV 

 THE EVOLUTION OF ANIMAL LIFE 



CHAPTER XVII 



THE EVIDENCES OF EVOLUTION 



1. The idea of evolution 2. Arguments for evolution : physio- 

 logical, morphological, historical . . . pp. 338-345 



