204 LIFE AND HABIT. 



line of an infinite number of generations are still one 

 pigeon only then we can understand that a bird, as 

 different from a peacock as a pigeon is now, could yet 

 have wandered on and on, first this way and then that, 

 doing what it liked, and thought that it could do, till it 

 found itself at length a peacock ; but we cannot believe 

 either that a bird like a pigeon should be able to appre- 

 hend any ideal so different from itself as a peacock, 

 and make towards it, or that man, having wished to 

 breed a bird anything like a peacock from a bird any- 

 thing like a pigeon, would be able to succeed in ac- 

 cumulating accidental peacock-like variations till he 

 had made the bird he was in search of, no matter in 

 what number of generations ; much less can we believe 

 that the accumulation of small fortuitous variations by 

 " natural selection" could succeed better. We can no 

 more believe the above, than we can believe that a 

 wish outside a plough-boy could turn him into a senior 

 wrangler. The boy would prove to be too many for his 

 teacher, and so would the pigeon for its breeder. 



I do not forget that artificial breeding has modified 

 the original type of the horse and the dog, till it has at 

 length produced the dray-horse and the greyhound ; but 

 in each case man has had to get use and disuse that 

 is to say, the desires of the animal itself to help him. 



We are led, then, to the conclusion that all races 

 have what for practical purposes may be considered as 

 their limits, though there is no saying what those 

 limits are, nor indeed why, in theory, there should be 

 any limits at all, but only that there are limits in 

 practice. Eaces which vary considerably must be con- 



