90 EVOLUTION 



Birds and sluggish Reptiles, we read alter- 

 natives or antitheses between activity and 

 passivity, between liberal expenditure of 

 energy and a more conservative habit of 

 storing. This primarily depends on the 

 ratio between disruptive ./Ica.t.fl-'hol^^ -p T *oof^ss* 3!S > 

 and constructive (anabolic) processes, and 

 till** 



game, contrast within a piven sp^ci^s. And 

 do not kindred yet contrasted forms, like 

 goat and sheep, wasp and bee, butterfly and 

 moth, seem as it were but the extreme ex- 

 pression of the same individual and sex 

 contrasts carried farther, upon the plane of 

 species, of genus, of order, or of class? 

 According to this view t& deep constjtu- 



female organism, which makes of the one a 

 sperm-producer and of the other an egg-pro- 

 ducer, is due to ftp iTiit.ia.1 



balance^ of chemical changes. The female 

 seems to be relatively the more construc- 

 tive, whence her greater capacity for organic 

 sacrifices in maternity; the male relatively 

 the more disruptive, whence his usually more 

 vivid life, his explosive energies in action. 

 Jn short T the sexes express p. fyndfl.menta.1 

 difference ip t.tip. rhythm nf 



This initial difference not only leads to the 

 primary functional distinction between male 



