Chap. VII. 



OSTEOLOGICAL DIFFERENCES. 



261 



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African cock, in a Frizzled cock from Madras, in two black-boned Silk hens, 

 no differences occur worth notice. In three Spanish cocks, the form of the 

 forehead between the orbits differs considerably ; in one it is considerably 

 depressed, whilst in the two others it is rather prominent, with a deep 

 medial furrow ; the skull of the hen is smooth. In three skulls of Sebright 

 Bantams the crown is more globular, and slopes more abruptly to the 

 occiput, than in G. bankiva. In a Bantam or Jumper from Burmah these 

 same characters are more strongly pronounced, and the supra-occiput is 

 more pointed. In a black Bantam the skull is not so globular, and the 

 occipital foramen is very large, and has nearly the same sub-triangular 

 outline presently to be described in Cochins ; and in this skull the two 

 ascending branches of the premaxillary are overlapped in a singular 

 manner by the processes of the nasal bone, but, as I have seen only one 

 specimen, some of these differences may be individual. Of Cochins and 

 Brahmas (the latter a crossed race approaching closely to Cochins) I 

 have examined seven skulls ; at the point where the ascending branches 

 of the premaxillary rest on the frontal bone the surface is much de- 

 pressed, and from this depression a deep medial furrow extends back- 

 wards to a variable distance ; the edges of this fissure are rather prominent, 

 as is the top of the skull behind and over the orbits. These characters are 

 less developed in the hens. The pterygoids, and the processes of the lower 

 jaw, relatively to the size of the head, are broader than in G. bankiva; and 

 this is likewise the case with Dorkings when of large size. The terminal 

 fork of the hyoid bone in Cochins is twice as wide as in G. bankiva, whereas 

 the length of the other 

 hyoid bones is only as 

 three to two. But the 

 most remarkable cha- 

 racter is the shape of 

 the occipital foramen : 

 in G. bankiva (A) the 

 breadth in a horizontal 

 line exceeds the height 

 in a vertical line, and 

 the outline is nearly 

 circular; whereas in Cochins (B) the outline is sub-triangular, and the 

 vertical line exceeds the horizontal line in length. This same form likewise 

 occurs in the black Bantam above referred to, and an approach to it may 

 be seen in some Dorkings, and in a slight degree in certain other breeds. 



Of Dorkings I have examined three skulls, one belonging to the white 

 sub-breed ; the one character deserving notice is the breadth of the frontal 

 bones, which are moderately furrowed in the middle ; thus in a skull which 

 was less than once and a half the length of that of G. bankiva, the breadth 

 between the orbits was exactly double. Of Hamburghs I have examined 

 four skulls (male and female) of the pencilled sub-breed, and one (male) 

 of the spangled sub-breed ; the nasal bones stand remarkably wide apart, 

 but in a variable degree ; consequently narrow membrane-covered spaces 

 are left between the tips of the two ascending branches of the premaxillary 



Fig. 33.— Occipital Foramen, of natural size. A. Wild Gallus 

 bankiva. B. Cochin Cock. 



