Darwinism 



zoology than the history of our domesticated 

 plants and animals. Many of them, like our 

 fowls and pigeons, are almost certainly descended 

 from one original wild species. Yet under do- 

 mestication there has arisen a great number of 

 races or breeds so different that, were they wild, 

 we should not hesitate to refer them to distinct 

 species or genera. Not only color and form of 

 feathers, but even the skeleton, as well as the 

 muscles, have been modified. Mr. Darwin says : 

 " Breeders habitually speak of an animal's or- 

 ganization as something quite plastic, which they 

 can model almost as they please. ... Sir John 

 Sebright used to say with respect to pigeons that 

 he would produce any given feather In three 

 years, but that It would take him six years to 

 obtain head and beak." 



The breeder depends for his success on three 

 facts. The first Is the law of heredity — like be- 

 gets like. If the parents are peculiar In some 

 respect, some of their children will Inherit this 

 peculiarity enhanced. In others It will be less 

 marked. The second fact Is the law of varia- 

 tion. The offspring Is probably never exactly 

 like either parent, and no two of the descendants 

 of a single pair are Identical. But the variation 



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