22o THE EVOLUTION OE SEX. 



SUMMARY. 



I. The essential fact in reproduction is the separation of part of the parent 

 organism to start a fresh life. 



II. Reproduction begins with rupture, — a katabolic crisis. 



III. Cell-division, which sometimes sums up, and is always associated with, 

 the act of reproduction, occurs at a katabolic crisis. 



IV. The gradations between discontinuous asexual multiplication and 

 ordinary sexual reproduction, show a lessening of the sacrifice ; but all demand 

 a disruption, or a katabolic preponderance. 



V. From first to last reproduction is linked to death. 



VI. Environmental conditions of a katabolic character favor sexual repro- 

 duction. 



VII. General conclusion, — a relative preponderance of katabolism neces- 

 sitates reproduction. 



LITERATURE. 



Geddes, P. — Theory of Growth, Reproduction, Sex, and Heredity. Proc. Roy. 



Soc. Edin. 1886. 

 Haeckel. — Generelle Morphologic 1866. 

 Spencer. — Principles of Biology. 

 Semper. — Animal Life. Int. Sci. Series. 1SS1. 

 Thomson. — "Synthetic Summary of the Influence of the Environment upon 



the Organism." Proc. Roy. Phys. Soc. Edin. 18S7. 



