THE DOCTRINE OF DESCENT. 13 



varieties of pigeons. Domestic pigeons and carrier- 

 pigeons, turbits and cropper-pigeons, fantail pigeons 

 and owls, tumblers and pouters, trumpeters and laugh- 

 ing pigeons (or Indian doves), and the rest, are all, as 

 Darwin has convincingly proved, descendants of a 

 single wild variety, the rock-pigeon (Columba livid). 

 And how wonderfully various they are, not only in 

 general form, size, and colouring, but in the particular 

 form of the skull, the beak, the feet, and so forth ! 

 They differ much more in every respect each from the 

 others than the numerous wild varieties which, in 

 systems of ornithology, are recognised as true varieties, 

 and even as true species. It is the same with the 

 different artificial varieties of apples, pears, pansies, 

 dahlias, and so on ; in short, of almost all the domestic 

 varieties of animals and plants. We would lay par- 

 ticular stress on the fact that these artificial species 

 which man has produced or created by artificial breed- 

 ing and through experimental transformation out of 

 one original species, differ far more one from another 

 in physiological as well as in morphological conditions 

 than the natural species in a wild state. With these 

 it is self-evident that any proof by experiment of a 

 common origin is wholly impossible. For, so soon as 

 we subject any wild variety of animal or plant to such 

 an experiment, we bring it under the conditions of 

 artificial breeding. 



