president's address. 221 



sterile. That there may be ex9eptions is what we should 

 naturally expect, in every case of a general rule. Now, Mr. 

 Darwin admits that he does not know of any thoroughly authen- 

 ticated cases of perfectly fertile hybrids, but has reason to believe 

 that one or two, as Pliasicmus colchicus, and torquatiis, are perfectly 

 fertile. But here he assumes a specific distinction, which 

 naturalists have long since rejected. For torquatus has been 

 generally acknowledged to be but the local variety of China. I 

 cannot venture to enter upon the cases of plants, which he 

 adduces; but his summary is, that in all other respects, excluding 

 fertility, there is a close resemblance between hybrids and mongrels, 

 and thus his conclusion is, that there is no fundamental distinc- 

 tion between species and varieties. I cannot but think that here 

 he concedes the whole argument to his opponents. The case of 

 domestic animals, especially pigeons, is adduced by him in support 

 of his view, and he appeals to us whether, did we not know to 

 the contrary, we should not unhesitatingly have put down the 

 varieties of domestic pigeons as species. I should reply that, 

 when we had ascertained their mutual fertility, and their ten- 

 dency to return to the original type of the rock-dove, which he 

 admits, we should not have done so. " But," says Mr. Darwin, 

 what man can do for his own purposes, nature, operating by the 

 laws of natural selection, could do if granted a period of sufacient 

 length, as the ^ons of geology." This is certainly true as an 

 hypothesis, but does it not need more corroborative evidence, while 

 our ignorance of the laws of variation is profound? 



Yet such power would Mr. Darwin assign to this process of 

 natural selection, that he maintains the wing of the bat, the 

 leg of the horse, and the claw of the lobster, to be all inherited 

 varieties from the same progenitor. We have been accustomed 

 to attribute these to unity of type. " But," says he, " on my 

 theory, unity of type is explained by unity of descent." Bather, 

 one might reply, in the words of Professor Owen, " the recogni- 

 tion of an ideal exemplar for the vertebrated animals proves that 

 the knowledge of such a being as man must have existed before 

 man appeared, for the Divine mind that planned the archetype 

 also foreknew all its modifications." Mr. Darwin frankly admits 



