CONTENTS. XV 



CHAPTER XV. 



PAGE 



Alternation of Generations .... 200-215 



§1. History of discovery. 



§ 2. Rhythm between sexual and asexual reproduction. 



§ 3. Alternation between sexual and degenerate sexual repro- 

 duction. 



§ 4. Combination of both these alternations. 



§ 5. Alternation of juvenile parthenogenetic reproduction 

 with the adult sexual process. 



§ 6. Alternation of parthenogenesis and ordinary sexual 

 reproduction. 



§ 7. Alternation of different sexual generations. 



§ 8. Occurrence of these alternations in animals. 



§ 9. Occurrence of alternations in plants. 

 § 10. The problem of heredity in alternating generations. 

 § II. Hints as to the rationale of alternation. 

 § 12. Origin of alternation of generations. 



BOOK IV.— THEORY OF REPRODUCTION. 

 CHAPTER XVI. 



Growth and Reproduction ----- 219-231 



§ I. Facts of growth. 



§ 2. Spencer's analysis. 



§ 3. Cell-division. 



§ 4. Protoplasmic restatement. 



§ 5. Antithesis between growth and reproduction. 



§ 6. The contrast in the individual — 



{a.) In distribution of organs. 



{/?.) In the periods of life. 

 § 7. The contrast between asexual and sexual reproduction. 



CHAPTER XVII. 



Theory of Reproduction — contimied - - - 232-238 



§ I. The essential fact in reproduction. 

 § 2. The beginning of reproduction. 

 § 3. Cell-division. 



§ 4. Gradations from asexual severance to liberation of sex- 

 cells. 

 § 5. The close connection between reproduction and death. 

 § 6. Reproduction as influenced by the environment. 

 § 7. General conclusion. 



