INTRODUCTION 3! 



than their parents ; and thus we get a further advance 

 of the good qualities of the hare, which grows on and 

 on, without end, because there is a corresponding 

 advance in the animals that have caused the improve- 

 ment in this case, the foxes. Darwin has shown 

 from the example of " artificial selection " selection 

 by the hand of man that such an improvement in 

 the characteristics of an animal can probably be brought 

 about by " natural selection." 



Breeders have succeeded, not only in increasing those 

 characteristics of domestic animals which they wish 

 to accentuate, but even in producing new ones, and 

 so in converting an animal gradually into one of a 

 quite different appearance. When we look at the 

 races of pigeons to-day, it is easy to believe that we 

 have before us quite different and independently 

 originating species. As a fact, some races of pigeons 

 differ from each other more than the pine-marten from 

 the stone-marten. What a difference there is in the 

 various parts of the body between pigeons ! The beak 

 of the turbit, for instance, is hardly visible, while the 

 " carrier " has a long beak with the most curious growth 

 hanging from it In many kinds the feet are clothed with 

 very thick plumage, in others they are quite bare. And 

 then there are the infinite diversities of colouring ! 



We find just the same if we take other illustrations. 

 Look at the difference between a pug and a grey- 

 hound, or an English race - horse and a Belgian 

 draught-horse! It is the same with cattle and pigs. 

 In every case we find races that differ most profoundly 

 from each other. 



