ARTIFICIAL SELECTION 341 



other valuable characters have been lost, since there was no 

 reason to suppose that the development of the one could 

 possibly affect the well-beinp^ of the other. Thus the " Game- 

 cock " bred by our forebears for the purpose of fighting has now 

 been changed so materially as to be quite unfit for its original 

 purpose — supposing this were still permitted. Similarly, in 

 the case of other breeds, prolificness has been lost in acquiring 

 other characters which appeal only to the eye. 



Man, in short, by selection, by breeding only from those 

 birds which possessed or gave promise of the qualities he 

 desired to improve, has been able to effect nothing short of a 

 transformation in the case of some birds, while in others he 

 has succeeded in changing but little. 



One would suppose, however, from the statements of some 

 writers, that the various domesticated races of, say. Pigeons 

 or Fowls, represent the consummation of some pre-conceived 

 standard or ideal : which is certainly not the case. In nature, as 

 Professor Poulton has aptly remarked. Variation leads. Natural 

 Selection follows: with domesticated races Variation leads, the 

 Breeder follows. 



Correlated variation is a factor which, however, has always 

 been beyond his control, and has often taken place unperceived 

 by him. In the matter of flight, most domesticated breeds 

 have degenerated, and this is chiefly due to the influence of 

 artificial selection — breeding from birds which showed no in- 

 clination to fly, as with Fowls and Ducks — and also, though 

 to a less appreciable extent, to the cessation of natural selection, 

 birds whose wings were below the minimum standard of 

 efficiency as organs of flight, being able to transmit their 

 tendency to degenerate wings to their offspring, because, living 

 under artificial conditions, the struggle for existence, in the 

 avoidance of enemies, or the search for food, has been removed. 



The various domesticated races, say, of Pigeons or Fowls, 

 which have been evolved more or less directly under human 

 control — by artificial selection — ^afford, it is commonly con- 

 tended, no real evidence in favour of the Darwinian theory of 

 the origin of species by natural selection. And this because 

 " natural " species are infertile inter se, while the domesticated 

 races, which superficially often differ far more widely one 

 from another than do closely allied " natural " species, are 



