Mental Evolution. 497 



to the offspring. There is the view which Mr. Wallace 

 adopts * with regard to the origin of accessory plumes, that 

 such variations may be due to "a surplus of strength, 

 vitality, and growth-power, which is able to expend itself 

 in this way without injury," and not without profit. The 

 development of the social habit, the mutual aid and protec- 

 tion thus afforded, may well have left a balance of the 

 life-energy, previously employed in individual self-preserva- 

 tion, available for this purpose. And then there is always 

 the hypothesis of favourable fortuitous variations to fall 

 back upon. 



On only one of these points do I propose to say a few 

 words that of the possible inheritance of acquired varia- 

 tions. 



Let us restate the problem here for the sake of clearness. 

 There is, according to the suggestion put forward in this 

 chapter, an interneural evolution, leading to an harmonious 

 development of the neuroses in the individual brain. But 

 this special evolution of the brain is nowise independent of 

 the more general evolution of the body. The human being, 

 as an organism, is still subject to natural elimination and 

 human selection. Elimination through the action of sur- 

 rounding physical conditions, although it has played some 

 part in the evolution of man, is not a factor of the first 

 importance. Elimination through enemies is more im- 

 portant, but has not much bearing on the question at 

 present before us the evolution of the conceptual. Elimi- 

 nation by competition, again, though a factor of yet greater 

 importance in human evolution, has, nevertheless, so far as 

 individuals are concerned, but little bearing on our present 

 question. Few are eliminated through the absence of the 

 conceptual faculty. Natural elimination, then, is, as Mr. 

 Wallace well pointed out, practically excluded in this 

 matter. No doubt, in the struggle between tribes and 



* " Darwinism," p. 293. It is strange that Mr. Wallace did not apply this 

 view to the mathematical and artistic faculties discussed in his last chapter. 

 It is true that such application tends to undermine the argument there 

 developed. But Mr. Wallace is far too great and conscientious a thinker to 

 be influenced by such a consideration. 



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