Evidences of Theory of Natural Selection. 297 



Or, to put it in another way, it may be said that 

 for thousands of years mankind has been engaged in 

 making a gigantic experiment to test, as it were by 

 anticipation, the theory of natural selection. For, 

 although this prolonged experiment has been carried 

 on without any such intention on the part of the ex- 

 perimenters, it is none the less an experiment in the 

 sense that its results now furnish an overwhelming 

 verification of Mr. Darwin's theory. That is to say, 

 they furnish overwhelming proof of the efficacy of the 

 selective principle in the modification of organic types, 

 when once this principle is brought steadily and con- 

 tinuously to bear upon a sufficiently long series of 

 generations. 



In order to furnish ocular evidence of the value of 

 this line of verification, I have had the following series 

 of drawings prepared. Another and equally striking 

 series might be made of the products of artificial 

 selection in the case of plants ; but it seems to me 

 that the case of animals is more than sufficient for the 

 purpose just stated. Perhaps it is desirable to add 

 that considerable care has been bestowed upon the 

 execution of these portraits ; and that in every case 

 the latter have been taken from the most typical 

 specimens of the artificial variety depicted. Those of 

 them which have not been drawn directly from life 

 are taken from the most authoritative sources ; and, 

 before being submitted to the engraver, they were all 

 examined by the best judges in each department In 

 none of the groups, however, have I aimed at an 

 exhaustive representation of all the varieties : I 

 have merely introduced representatives of as many 

 as the page would in each case accommodate. 



