40 Mutability and Individual Variation. 



object to show that animals and plants do perpetually 

 vary in the manner and to the amount requisite.^ Single 

 variations he regards as absokitely without significance; 

 they have played no part (he says), or at most hardly 

 any, in the origin of species.^ 



Our author holds himself to be at one with Darwin 

 in essentials and only to have rendered his selection 

 theory sharper and more precise. The hosts of doubts 

 which, as we saw in the preceding section, were always 

 so carefully brought forward and discussed by Darwin, 

 disappear. The theory has become a compact, clear and 

 surprisingly simple one. Wallace takes just as careful 

 account of the systematic and biological facts as Darwin 

 did in his cautious way, but Wallace^s theory is much 

 more convenient and attractive than Darwin's. 



This very clearness in the mode of presentation makes 

 it easy for the critic to discover the weak spot. In fact 

 the author himself almost lays his finger on it. At the 

 end of the first section he gives a summary of his collec- 

 tion of facts and the method of his proof ; and one has 

 only to follow carefully to discover the weak point in 

 his argument.'^ 



It will be useful to recapitulate as briefly as may be 

 this argument. 



Wallace's theory of natural selection rests on two 

 series of facts. The first is the rapid multiplication and 

 the resulting premature death of innumerable individuals. 

 The second is variability and the survival of the fittest. 

 Against this part of his argument I have no objection to 

 raise. He then goes on to consider another im.portant 



^Darwinism, 2d. ed., p. 13. 



'"My whole work tends forcibly to illustrate the overwhelming 

 importance of natural selection." Wallace, loc. cit., pp. vii-viii. 



^Darwinism, pp. 12, 13. 



