InflLtence of Erivironmeiit upon the Organism. 405 



the general organism may rapidly affect even the reproductive 

 elements. If Sedgwick's view of the syncytial or plasmodial 

 constitution of the embryo Peripatus be confirmed and ex- 

 tended ; if protoplasmic continuity, so widely demonstrated 

 in plants, be also, to some extent, true of animals, then our 

 conception of the diffusion of a change will have to be 

 modified. The question, in fact, is not whether direct 

 environmental action may occur or nob, nor whether it may 

 be inherited or not, but simply how soon the influence may 

 so saturate through the organism, as to become, by affecting 

 the reproductive elements, transmissible. 



12. Relation of " Unvirojimental" to other Variations. — 

 Without forestalling the last division of this paper, it may be 

 convenient to note the relation of environmental to other 

 variations. Combining the various theories of the conditions 

 of change, we may describe variations as originating {a) from 

 within, (h) from without, and {c) in the course of function. 

 Variations may originate, according to some {e.g., 210), strictly 

 from within, because of the unstable complexity of in- 

 ternal structure — protoplasmic or otherwise — which makes 

 equilibrium all but impossible. These (a) may be spoken of 

 by themselves as " organismal variations." According to 

 others, they may originate in the way above described from 

 the varying nature of external influences. These (h) may be 

 termed '' environmental variations." Or changes may be 

 brought about by altered activity, itself a response to altered 

 relations of the organism and its environment. Those {c) 

 variations especially emphasised by Lamarck, may be con- 

 veniently described as " functional." 



13. The Action of the Environment as a Factor in Organic 

 Evolntion. — The history of opinion in regard to the action of 

 the environment as a factor in organic evolution, may fairly 

 begin with Buffon. In his waitings from 1749 onwards, 

 Buffon makes it evident that he believed the surroundings 

 to be a direct cause of variation within the organism. He is, 

 in this respect, contrasted with Erasmus Darwin (1794), who 

 credited the surroundings with a merely indirect modifying 

 influence. Herder too, in his discussion of human races, 

 laid emphasis on the influence of heat and climate ; while 



