256 FOWLS. Chap. VII 



with the mottling partially and obscurely arranged in trans- 

 verse lines. But the tendency to pencilling is probably 

 much strengthened by the law of analogous variation, for the 

 hens of some other species of Gallus are more plainly pencilled, 

 and the hens of many gallinaceous birds belonging to other 

 genera, as the partridge, have pencilled feathers. ' Mr. Teget- 

 meier has also remarked to me that, although with domestic 

 pigeons we have so great a diversity of colouring, we never 

 see either pencilled or spangled feathers ; and this fact is 

 intelligible on the law of analogous variation, as neither the 

 wild rock pigeon nor any closely allied species has such 

 feathers. The frequent appearance of pencilling in crossed 

 birds probably accounts for the existence of " cuckoo " sub- 

 breeds in the Game, Polish, Dorking, Cochin, Andalusian, 

 and Bantam breeds. The plumage of these birds is slaty- 

 blue or grey, with each feather transversely barred with 

 darker lines, so as to resemble in some degree the plumage 

 of the cuckoo. It is a singular fact, considering that the 

 male of no species of Gallus is in the least barred, that the 

 cuckoo-like plumage has often been transferred to the male, 

 more especially in the cuckoo Dorking ; and the fact is all the 

 more singular, as in gold- and silver-pencilled Hamburghs, 

 in which pencilling is characteristic of the breed, the male is 

 hardly at all pencilled, this kind of plumage being confined to 

 the female. 



Another case of analogous variation is the occurrence of 

 spangled sub-breeds of Hamburgh, Polish, Malay, and Bantam 

 fowls. Spangled feathers have a dark mark, properly crescent- 

 shaped, on their tips ; whilst pencilled feathers have several 

 transverse bars. The spangling cannot be due to reversion to 

 G. banhira ; nor does it often follow, as I hear from Mr. Teget- 

 meier, from crossing distinct breeds; but it is a case of 

 analogous variation, for many gallinaceous birds have spangled 

 feathers, — for instance, the common pheasant. Hence spangled 

 breeds are often called " pheasant "-fowls. Another case of 

 analogous variation in several domestic breeds is inexplicable ; 

 it is, that the chickens, whilst covered with down, of the 

 black Spanish, black Game, black Polish, and black Bantam, 

 all have white throats and breasts, and often have some white 



