LAWS OF MULTIPLICATION. 299 



SUMMARY. 



1. The rate of reproduction is chiefly determined by the constitution of 

 the organism ; the rate of increase, by its relations to the animate and 

 inanimate environment. 



2. The naturalist has to thank the sociologist for directing emphatic 

 attention to the laws of multiplication. 



3. Summary of Spencer's analysis. Individuation and genesis vary 

 inversely. 



4. In regard to man, Spencer urges the importance of pressure of popu- 

 lation as an incentive to progress, and concludes that man's future evolution 

 must continue mainly in the direction of psychical development, and pre- 

 dicts with the increase of individuation a diminution of fertility. 



5. Predecessors and opponents of Malthus denied that increase of 

 population tended to outrun subsistence ; Malthus successfully demon- 

 strated his thesis, and noted the checks which curbed the increase ; Darwin 

 emphasised the advantage of the pressure and checks ; Spencer shows the 

 inverse ratio of degree of development and rate of reproduction ; neo- 

 Malthusians advocate the use of artificial preventive checks to fertilisation. 

 Discussion of these various generalisations and proposals. 



6. Completed imlividuation, were that possible, would be theoretically 

 associated with sterility. 



LITERATURE. 



Malthus. — Theory of Population. 1806. 



Spencf:r. — Principles of Biology. Lond. 1866. 



Geddes. — " Reproduction," Ency. Brit. ; and Lecture on Claims of 



Labour. Edin. 1886. 

 Drysdale. — The Population Question. Lond. 1878. 

 Besant. — The Law of Population. Lond. n.d. 

 Clapperton.— Scientific Meliorism. Lond. 1885. 



