Chap VII. EXTERNAL DIFFERENCES. 269 



with si)urs ; and in Germany, according to Bochstein,^^ the 

 spurs in the bilk hen are sometimes very long. He mentions 

 also another breed similarly characterised, in which the hens 

 are excellent layers, but are apt to disturb and break their 

 eggs owing to their spurs. 



Mr. Layard" has given an account of a breed of fowls in 

 Ceylon with black skin, bones, and wattle, but with ordinary 

 feathers, and which cannot " be more aptly described than by 

 comparing them to a white fowl drawn down a sooty chimney ; 

 it is, however," adds Mr. Layard, " a remarkable fact that a 

 male bird of the pure sooty variety is almost as rare as a 

 tortoise-shell tom-cat." I\lr. Blyth found the same rule tc 

 hold good with this breed near Calcutta. The males and 

 females, on the other hand, of the black-boned European 

 breed, with silky feathers, do not ditfer from each other; so 

 that in the one breed, black skin and bones and the same 

 kind of plumage are common to both sexes, whilst in the other 

 breed, these characters are confined to the female sex. 



At the present day all the breeds of Polish foAvls have the 

 great bony protuberance on their skulls, which includes part 

 of the brain and supports the crest, equally developed in both 

 sexes. But formerly in Germany the skull of the hen alone 

 was protubeiant : Blumenbach,^* who particularly attended 

 to abnormal ])eculiarities in domestic animals, states, in 1805, 

 that this was the case ; and Bechstein had previously, in 

 17!i3, observed the same fact. This latter author has care- 

 fully described the effects on the skull of a crest not only in 

 the case of fowls, but of ducks, geese, and canaries. He states 

 that with fowls, when the crest is not much developed, it is 

 supported on a fatty mass ; but when much developed, it is 

 always supported on a bony protuberance of variable size. 



'•* ' Naturgeschichte Deutschlands,* count, has disputed the accuracy of 



Band iii. (1703), s. 339, 407. Blumenbach's statement. Fur Bech- 



^' On the Ornithologv of Cevlo_ .n stein, .see ' Naturg;eschichte Deutsch- 



' Annals and Mag. of Nat. History.' lands,' Band iii. (1793), s. 399, note. I 



'2nd series, vol. xiv. (186-i), p. 63. may add that at the first exhibition of 



'* ' Handbuch der vergleich. Ana- Poultry at the Zoological Gardens, in 



tomie,' 1805, p. 85, note. Mr. Teget- May, 1845, I saw some fowls, called 



meier, who gives in ' Proc. Zoolog. Friezland fowls, of which the hens 



Soc.,' Nov. 25th, 1856, a very interest- were crested, and the cocks furnished 



ing account of the skulls of Polish with a comb, 

 fowls, not knowing of Bechstein's ac- 



