Evidences of Theory of Natural Selection. 313 



different directions must in this case have been 

 produced by artificial selection in so comparatively 

 short a time— the first mention of this bird that I can 

 find being by Gesner, in the sixteenth century. 



Now, it is surely unquestionable that in these 

 typical proofs of the efficacy of artificial selection in 

 the modification of specific types, we have the strongest 

 conceivable testimony to the power of natural selection 

 in the same direction. For it thus appears that 

 wherever mankind has had occasion to operate by 

 selection for a sufficiently long time — that is to say, on 

 whatever species of plant or animal he chooses thus to 

 operate for the purpose of modifying the type in any 

 required direction, — the results are always more or less 

 the same : he finds that all specific types lend them- 

 selves to continuous deflection in any particulars of 

 structure, colour, &c., that he may desire to modify. 



Nevertheless, to this parallel between the known 

 effects of artificial selection, and the inferred effects of 

 natural selection, two objections have been urged. 

 The first is, that in the case of artificial selection the 

 selecting agent is a voluntary intelligence, while in the 

 case of natural selection the selecting agent is Nature 

 herself ; and whether or not there is any counterpart 

 of man's voluntary intelligence in nature is a question 

 with which Darwinism has nothing to do. Therefore, 

 it is alleged, the analogy between natural selection 

 and artificial selection fails ab initio, or at the fountain- 

 head of the causes which are taken by the analogy to 

 be respectively involved. 



The second objection to the analogy is, that the 

 products of artificial selection, closely as they may 



