142 BLASTOGENIC VARIATIONS. 



Similar phenomena show themselves in other domestic 

 animals besides the pigeon, though they are seldom so 

 striking or so clear. Thus in some cases the wild an- 

 cestor or ancestors are quite unknown, and hence one is 

 debarred from coming to any certain conclusions as to 

 whether reversion is present or not. The Game fowl, 

 however, and probably most other domestic breeds 

 of fowl, may with considerable confidence be de- 

 rived from the jungle fowl, Gallus bankiva. Now 

 purely bred Game, Malay, Cochin, Dorking, Bantam, 

 and Silk fowls may frequently or occasionally be met 

 with, which are almost identical in plumage with the 

 wild Gallus bankiva. The most striking instance ob- 

 tained by Darwin * is one in which a glossy green-black 

 Spanish cock was crossed with a diminutive white Silk 

 hen. Both of these breeds are ancient, and have long 

 been known to breed true. All the offspring from this 

 cross were coal black, and all plainly showed their 

 parentage in having blackish combs and bones; but as 

 the young cocks grew, one became a gorgeous bird, 

 closely resembling the wild G. bankiva, but with the red 

 feathers rather darker. In all but a few details there 

 was the closest resemblance. 



In recent years a series of interesting observations 

 has been carried out by von Guiata upon mice.f 

 Fifty-five Japanese waltzing mice were crossed with 

 white mice belonging to a race bred by Weismann for 

 eight years, and these crosses were continued through 



* L. c. ii. p. 253. 



fBer. Naturf. Ges. zu Freiburg. Bd. x. p. 317, 1898, and Bd. xi. 

 p. 131, 1900. Review by Davenport in Biol. Bulletin, ii. p. 121, 

 1901. 



