CONTENTS. XI 



CHAPTER XV. 



PAGE 



Alternation of Generations 185-199 



I. History of discovery. 



II. Rhythm between sexual and asexual reproduction. 



III. Alternation between sexual and degenerate sexual repro- 



duction. 



IV. Combination of both these alternations. 



V. Alternation of juvenile parthenogenetic reproduction, 

 with the adult sexual process. 



VI. Alternation of parthenogenesis and ordinary sexual 



reproduction. / 



VII. Alternation of different sexual generations. 



VIII. Occurrence of these alternations in animals. 

 IX. Occurrence of alternations in plants. 



X. The problem of heredity in alternating generations. 

 XI. Hints as to the rationale of alternation. 

 XII. Origin of alternation of generations. 



BOOK IV.— THEORY OF REPRODUCTION. 

 CHAPTER XVI. 



Growth and Reproduction - - - 203-214 



I. Facts of grov\t'.i. 



II. Spencer's analysis. 



III. Cell-division. 



IV. Protoplasmic restatement. 



V. Antithesis between growth and reproduction. 



VI. The contrast in the individual — 



fa) In distribution of organs. 

 (b) In the periods of life. 



VII. The contrast between asexual and sexual reproduction. 



CHAPTER XVII. 

 Theory of Reproduction — continued . . . . 215-220 



I. The essential facts in reproduction. 



II. The beginning of reproduction. 



III. Cell-division. 



IV. Gradations from asexual severance to liberation of sex. 



cells. 

 V. The close connection between reproduction and death. 



VI. Reproduction as influenced by the environment. 



VII. General conclusion. 



