Chap. VII. EXTERNAL DIFFERENCES. 269 



with spurs ; and in Germany, according to Bechstein, 56 the 

 spurs in the Silk 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 57 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." Mr. Blyth found the same rule to 

 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 differ from each other; so 

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

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

 breed, these characters are confined to the female sex. 



At the present day all the breeds of Polish fowls 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 protuberant : Blumenbach, 58 who particularly attended 

 to abnormal peculiarities in domestic animals, states, in 1805, 

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

 1793, 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. 



56 ' Naturgeschichte Deutschlands,' count, has disputed the accuracy of 



Band iii. (1793), s. 339, 407. Blumenbach's statement. For Bech- 



37 On the Ornithology of Ceylon in stein, see ' Naturgeschichte Deutsch- 



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



2nd series, vol. xiv. (1854), p. 63. may add that at the first exhibition of 



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



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



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



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



ing account of the skulls of Polish with a comb, 

 low!;, not knowing of Bechstein's ac- 



