DARWINISM 153 



plants live under precisely the same conditions of life, respec- 

 tively, they show no signs of changing. They only exhibit 

 trivial individual, mostly inconstant differences, of which no 

 systematist takes any notice. Though it was upon these that 

 Darwin laid stress. 



He thus wrote : " No one supposes that all the individuals 

 of the same species are cast in the same actual mould. These 

 individual differences are of the highest importance for us, for 

 they are often inherited . . . and they afford materials for 

 Natural Selection to act on and accumulate." ^ 



" Let it be borne in mind how infinitely complex and close- 

 fitting are the mutual relations of all organic beings to each 

 other and to their physical conditions of life ; and consequently 

 what infinitely varied diversities of structure tnight be of use 

 to each being under changing conditions of life. Can it, then, 

 be thought improbable, seeing that variations useful to man have 

 undoubtedly occurred, that other variations useful in some way 

 to each being in the great and complex battle of life, should 

 occur in the course of many successive generations? 7/" such 

 do occur can we doubt (remembering that many more individuals 

 are born than can possibly survive) that individuals having any 

 advantage, however slight, over others, would have the best 

 chance of surviving and of procreating their kind? On the 

 other hand, we may feel sure that any variation in the least 

 degree injurious wo2ild be rigidly destroyed. 



"This preservation of favourable individual differences and 

 variations, and the destruction of those which are injurious, 

 I have called Natural Selection, or the Survival of the Fittest." ^ 



Besides differing from Darwin as to cultivation and domes- 

 tication affording any basis for comparison with wild plants 

 and animals, Dr. Wallace does not accept these " individual 

 differences " as means for originating species. He thus writes : 

 " In securing the development of new forms in adaptation to 



1 Origin of Species, p. 34. I would refer the reader to my paper on 

 " Individual Variations," in Natural Science, vol. vi., p. 385. 

 "^Origin of Species, p. 623. The italics are mine. 



