92 HEREDITARY CHARACTERS 



necessary. On the other hand, fluctuating variations con- 

 stantly appear in every character. 



The following metaphor puts the situation in a very lucid 

 manner : 



"Darwin's view, that Selection is the paramount power 

 in the production of species, is made very clear by his 

 metaphor of an architect constructing a beautiful building 

 out of the fragments of broken stone at the foot of a 

 precipice. 1 For the purpose of the controversy of the hour, 

 a more appropriate metaphor is that of the artist. Pictorial 

 effects could no doubt be obtained from time to time by the 

 simple method of throwing colours at a screen ; occasionally, 

 perhaps, such ' Mutations ' would be superior to anything 

 which an artist could achieve by adding here a little and 

 there a little to the developing picture. It would hardly be 

 reasonable to infer from a few such successes that the proper 

 function of the artist is merely to wait for the appropriate 

 Mutation, and to cease producing effects by the accumulation 

 of minute increments in fact, ' to select not to create.' The 

 essential difficulty about the chance method is that it could 

 never yield representations of particular objects. Now there 

 is an important section of the organic world where the meta- 

 phor passes into reality. I refer to the countless thousands 

 of cases in which there has been evolved on the surface of 

 an animal a picture of some portion of its environment the 

 unending instances of Protective Resemblance and the still 

 more striking examples of Mimicry. Is is as unlikely that a 

 key could be made to fit a complicated lock by a number of 

 chance blows upon a blank piece of metal, as that the 

 elaborate pattern on the wings of a butterfly should have 

 been reproduced on those of its mimic by Mutation." 2 



It might of course be claimed that adaptation is brought 

 about by a number of small mutations. Apart from the fact 

 that this seems to be against the writings of de Vries and 

 his supporters, 3 such an interpretation would throw an even 



1 Variation under Domestication, London, 1875, vol. ii. pp. 426-27. 



2 Poulton, op. cit., p. xxiii of Introduction. 3 See pp. 72, 73. 



