296 Darwin, and after Darwin 



festation of useful qualities on the one hand, and of 

 beautiful qualities on the other, according as the 

 organisms have been thus bred for purposes of use or 

 for those of beauty. 



Now it is immediately obvious that in these cases 

 the process of artificial selection is precisely analogous 

 to that of natural selection (and of sexual selection 

 which will be considered later on), in all respects save 

 one : the utility or the beauty which it is the aim of 

 artificial selection continually to enhance, is utility or 

 beauty in relation to the requirements or to the tastes 

 of man ; whereas the utility or the beauty which is 

 produced by natural selection and sexual selection has 

 reference only to the requirements or the tastes of 

 the organisms themselves. But, with the exception 

 of this one point of difference, the processes and the 

 products are identical in kind. Persevering selection 

 by man is thus proved to be capable of creating what 

 are virtually new specific types, and this in any 

 required direction. Hence, when we remember how 

 severe is the struggle for existence in nature, it 

 becomes impossible to doubt that selection by nature 

 is able to do at least as much as artificial selection in 

 the way of thus creating new types out of old ones. 

 Artificial selection, indeed, notwithstanding the many 

 and marvellous results which it has accomplished, can 

 only be regarded as but a feeble imitation of natural 

 selection, which must act with so much greater 

 vigilance and through such immensely greater periods 

 of time. In a word, the proved capabilities of arti- 

 ficial selection furnish, in its best conceivable form, 

 what is called an argument a fortiori in favour of 

 natural selection. 



