THE CROSSING, AC, OF PIGEONS AND FOWLS. 243 



Not only is the principle illustrated, in these two 

 species, the Pigeon and Fowl, of a distribution, among 

 several and distinct varieties, of the characters regained ; 

 but, the effects of all the other processes of the forma- 

 tion of varieties, are also observable, in varieties of 

 these two species. Disproportionate development, 

 with the varieties of these species, is effected, not 

 merely by failure to develop all of the characters, con- 

 currently, in each individual, but also by direct degen- 

 eration, — by the direct suppression or reduction of fea- • 

 tures which had escaped the ordeal of the Struggle for 

 Existence. 



Such species should, ex hypothesi, be notable for evil 

 effects when their individuals are bred in-and-in. If, 

 for instance, the individuals of the Fantail variety which 

 is below referred to, lack not only the full develop- 

 ment of the peculiar character of their variety, but 

 lack also, all of the positive peculiarities of all the other 

 varieties of their species, — which they needs must, — it 

 is manifest, that interbreeding will, by the physiological 

 effects, wrought upon such individuals, decide posi- 

 tively, one way or the other, whether evil flows, from 

 the departure of the individuals from the type of the 

 sum of all the positive features of their species. 



If the individuals of a variety, not only lack all the 

 positive peculiarities of the other varieties, but are dis- 

 tinguished from the others by a negative, instead of a 

 positive, feature, the evil effects of close-interbreeding 

 should, a priori, be the greater. 



Darwin says (p. 237, Vol. ii, Animals and Plants, &c) : 



"A great winner of prizes at the Pigeon shows, in de- 



