340 SYMBWGENES1S 



rational, more comprehensive and more valid than one which 

 is satisfied with purely chemico-physiological factors. By 

 entertaining a Goethian idea of " cosmic " adaptation, 

 however, it may be said that Prof. Eimer has obtained a kind 

 of intuitive guiding principle as regards evolution by which to 

 measure definite variations. 



When he states, moreover, that " sexual separation has 

 developed on the basis of the advantage of division of labour, 

 and the prevention of in-and-in-breeding," we see that he is 

 willing to recognise some kind of broad principle of utility. 

 That the true and determining utility here concerned, how- 

 ever, is a bio-economic utility is worth emphasising once more. 



Prof. Eimer recognises that an "adaptation" may be 

 " necessary or useful to other creatures or to the generality of 

 things," and he would distinguish the latter as "general" or 

 "cosmic" adaptation from "special" adaptation. 



Individuals during their life also adapt themselves to the external 

 world consider only the variety of the experience which individual 

 animals during life, according to their surroundings and their intelli- 

 gence, meet with and benefit by, or the special strength of body or any 

 other useful qualities which they acquire in consequence of the external 

 demands upon them. 



Amongst six "particular causes which determine the 

 differences in the direction of evolution, and which also con- 

 tribute to bring about the division into species," he mentions 

 indeed "the functional activity of the organism in relation to 

 the external world, which directly strengthens characters in 

 process of development by the exercise of them," but he is 

 still a long way from realising how such " cosmic " adaptation 

 is bio-economic in character and is so among the most 

 important of all determining causes. 



Speaking of sexual mixing as a determining cause of 

 evolution, he tells us that: 



The sperm-nucleus and the egg-nucleus must in their physio-chemical 

 properties form with perfect exactness the complements of one another, 

 if through their union a new organism is to be produced, 

 which shows how high the requirements are of reciprocal 



