Chai\ YII. 



OSTEOLOGICAL DIFFERENCES. 



281 



pair in other skeletons ; in this Game cock, as far as coukl be 

 judged from the appearance of the himbar yertebrfe, a "whole dorsal 

 vertebra with its ribs was missing. We thus see that the ribs 

 (whether or not the little jiair attached to the fourteenth cervical 

 vertebra be counted) vary from six to eight pair. The sixth paii* is 

 frequently not furnished with processes. The sternal portion of 

 the seventh pair is extremely broad in Cochins, and is completely 

 ossified. As previously stated, it is scarcely possible to coimt the 

 lumbo-sacral vertebrfe ; but they certainly do not correspond in 

 sliape or number in the several skeletons, Tlie caudal vertebra? 

 ai"e closely sinnlar in all the skeletons, the only difference being 

 ■whether or not the basal one is anchylosed to the pelvis; they 

 hardly vary even in length, not being shorter in Cochins, with their 

 short tail-feathers, than in other breeds ; in a Spanish cock, 

 however, the caudal vertebrse were a little elongated. In three 

 rumpless fowls the caudal vertebrae were few m number, and 

 anchylosed together into a misformed mass. 



In the individual vertebra? the differences in structure are very 

 slight. In the atlas the cavity for the occipital condyle is either 

 ossified into a ring, or is, as in Bankiva, 

 open on its upper margin. The upper arc 

 of the spinal canal is a little more arched 

 in Cochins, in conformity with the shape 

 of the occipital foramen, than in G. hankiva. 

 In several skeletons a difference, but not 

 of much importance, may be observed, 

 which commences at the fourth cervical 

 vertebra, and is gieatest at aliout the 

 sixth, seventh, or eighth vertebra; this 

 consists in the hfemal descending processes 

 being united to the body of the vertebra 

 by a sort of buttress. This structure may 

 be observed in Cochins, Polish, some Ham- 

 burghs, and probably other breeds ; but 

 is absent, or barely -developed, in Game, Dorking, Spanish, Bantam, 

 and several other breeds examined by me. On the dorsal surface 

 of the sixth cervical vertebra in Cochins three prominent points 

 are more strongly developed than in the corresponding vertebra 

 of the Game fowl or G. hankiva. 



Pdvis.—This differs in some few points in the several skeletons. 

 The anterior margin of the ilium seems at first to vary much in 

 outline, but this is chiefly due to the degree to which the margin 

 in the middle part is ossified to the crest of the vertebra? ; the outline, 

 however, does differ in being more truncated in Bantams, and more 

 rounded in certain breeds, as in Cochins. Tlie outline of the 

 ischiadic foramen differs considerably, being nearly circular in 

 Bantams, instead of egg-shaped as in the Bankiva, and more 

 regularly oval in some skeletons, as in the Siianish. The obturator 

 notch is also much less elongated in some skeletons than in others. 



Fifr. 37— Sixth Cervical Vertebra, 

 ofn.itiiral size, viewed laterally. 

 A. AViM (Callus bankiva. B. 

 Cocbiu Cocli. 



