CHAPTER IV. 



SPECIAL CHARACTERS OF THE CERVICAL VERTEBRAE IN THE 



MAMMALIA. 



ORDER PRIMATES.- -The human cervical vertebrae (ex- 

 cluding for the present the first and second) have short, 

 wide, depressed bodies, hollowed in front from side to side, 

 and behind from above downwards, 1 with wide neural canals, 

 and short, broad, and usually bifid spines (considerably 

 longer in the seventh vertebra than in the others), well 

 marked, broad, flat, anterior and posterior zygapophyses, 

 and short, sub-bifid, widely perforated transverse processes. 



These vertebrae are, as usual, developed mainly from three 

 centres, one for each side of the arch, and one for the 

 centrum (see Fig. 8), but it will be observed that the whole 

 of the body is not formed from the latter, but that its lateral 

 parts, with the transverse processes, are ossified from the 

 arches. 



Besides these main centres of ossification there are thin 

 and imperfect disk-like epiphyses on the ends of the body, 



1 As before mentioned, the body is supposed to be placed horizontally, 

 so that the same terms of relative position may be used as when speak- 

 ing of the vertebral column of the ordinary less modified animals of the 

 class. 



