vin DARWINISM AND HOLISM 219 



infer from Darwinism, in either its earlier or its later (Weis- 

 mann) form. It is not merely a case of one factor creating 

 variations, and another eliminating some of these creations 

 and leaving free the rest, which are then said to be selected 

 for perpetuation. The inner creative factor in a measure 

 acts directly under the stimulus of the external factor, and 

 the variations which emerge are the result of this intimate 

 interaction. The isolation of the inner from the outer factor, 

 which was so much emphasised by Weismann, is, in spite 

 of its apparent agreement with observation, really a mis- 

 taken assumption, based on the neglect of the factor of time 

 in Evolution. Environment is a great stimulus of varia- 

 tion, and even more so is the somatic organism itself, 

 which is closer to the germ-cell than the environment. 



We can understand the process of organic Evolution only 

 if we assume that, deeply as the germ-cell carriers of Varia- 

 tion are hid from external contacts, they are not completely 

 or for ever isolated therefrom; that changes due to habitual 

 behaviour or to environmental or ecological pressure affect 

 the " field " of the germ-cells, and if sufficiently long-con- 

 tinued and intense, sooner or later penetrate the structures of 

 these germ-cells, and stimulate and set in motion the internal 

 factor of Variation. The response comes back in a crisis of 

 variation or mutation which permanently alters the internal 

 hereditary structure. In these cases the inner and outer 

 factors of Evolution do not operate independently and by 

 opposed and contrasted methods; they collaborate in the 

 closest manner as the stimulus and response which we find 

 distinctive of all organic action. From this external factor, 

 which operates as a stimulus of organic variation, we have 

 to distinguish Darwin's Natural Selection, which is another 

 external factor operative not in connection with the stimula- 

 tion of variations, but in connection with their subsequent 

 elimination or destruction. The external factors in Evolu- 

 tion are therefore according to this view twofold: the 

 environmental or ecological factor which to some extent 

 influences or induces variation, and the factor of organic 

 struggle which sets in motion the warfare among organisms 



