EVOLUTION THEORIES 219 



thereby, despite services to evolutionary 

 biology second only to Darwin's own, he 

 failed to widen the interests of fellow-workers 

 henceforth specialized, and perhaps rather 

 intensified their reluctance to venture be- 

 yond their immediate problems. They too 

 were doubtless so far right in this: their re- 

 examination of Nature in the light of the 

 Darwinian theory has been a great task. 

 But now on many sides fresh chapters of 

 evolutionary study are opening, and there 

 are many workers who feel free, even con- 

 strained, to relate and unify the phenomena 

 of development of plants and animals and 

 man, the intricacies of structures and func- 

 tions, variations and diseases, amid which 

 have lain our various individual trainings 

 as organic evolutionists, with those of other 

 evolutionists, not only the cosmic, but the 

 social. Hence, then, the planning of this 

 little book which starting with the social 

 origins of biological evolution theories, next 

 naturally gives its main bulk to the bio- 

 logical theories themselves, but increasingly 

 suggests the fruitful parallel of organic and 

 social evolution; and now, as it draws to- 

 wards conclusion, it argues with more and 

 more insistence for the conscious renewal 

 of this, as a working partnership hence- 

 forward. 



