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fU> 



Chap. VII. EXTEENAL DIFFEKENCES. 257 



But formerly in Germany the skull of the hen alone was protu- 

 berant: Blumenbach, 58 who particularly attended to abnormal 

 peculiarities in domestic animals, states, in 1813, that this 

 was the case ; and Bechstein had previously, in 1793, observed 

 the same fact. This latter author has carefully described the 

 effects of a crest on the skull not only in fowls, but in 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 pro- 

 tuberance of variable size. He well describes the peculiarities 

 of this protuberance, and he attended to the effects of the 

 modified shape of the brain on the intellect of these birds, and 

 disputes Pallas' statement that they are stupid. He then 

 expressly states that he never observed this protuberance in 

 male fowls. Hence there can be no doubt that this remarkable 

 character in the skulls of Polish fowls was formerly in Germany 

 confined to the female sex, but has now been transferred to the 

 males, and has thus become common to both sexes. 



External Differences, not connected with the sexes, between the 

 breeds and between individual birds. 



The size of the body differs greatly. Mr. Tegetmeier has known a 

 Brahma to weigh 17 pounds; a fine Malay cock 10 pounds; whilst a first- 

 rate Sebright Bantam weighs hardly more than 1 pound. During the last 

 20 years the size of some of our breeds has been largely increased by 

 methodical selection, whilst that of other breeds has been much diminished 

 We have already seen how greatly colour varies even within the same 

 breed; we know that the wild G. bankiva varies slightly in colour; we 

 know that colour is variable in all our domestic animals; nevertheless 

 some eminent fanciers have so little faith in variability, that they have 

 actually argued that the chief Game sub-breeds, which differ from each 

 other m nothing but colour, are descended from distinct wild species! 

 crossing often causes strange modifications of colour. Mr. Tegetmeier 

 informs me that when buff and white Cochins are crossed, some of the 



vu A? Blumenbach on the authc >- geschichte Deutschlands,' Band iii. 



my ot Mr Tegetmeier, who gives in (1793), s. 399, note. I may add that at 



Pioc. Zoolog. Soo.. Nov. 25th, 1856, a the first exhibition of poultry at the 



Po 3T / eS ^ \T Unt ° f ^ SkullS ° f ^Og^ hardens, in May, 1845, 1 saw 



know I" D f*' Te S etmeier > not s °me fowls, called Friezland fowls, of 



bZwI Bechstems account, dis- which the hens were crested, and the 



ihfcttJ? i r Ur t Cy , ° f • Blumenbach ' s ^cks were furnished with a comb, 

 statement. For Bechstein, see ' Natur- 



VOT,. I 



