SKELETON OF ARTIODACTYLA. 477 



even slightly bent back beyond that line. The great freedom 

 given to the movements of the head relate, like the length of neck 

 and general altitude of the body, to the culling of lea^4 from the 

 trees browzed on by the Giraffe. The part of the skull to which 

 the elastic ligament is attached is raised considerably above the roof 

 of the cranial cavity by the extension back^vard of laro-e sinuses 

 or air-cells, as far as the occiput, fig. 326. The sinuses com- 

 mence above the middle of the nasal ca^dty, and increase in 



Skull of narl)ary D.-or (Cerrns elajihiis) 



depth and Avidth to beneath tlie base of the horns, where their 

 vertical extent equals that of the cerebral cavity itself. The 

 exterior table of the skull, thus widely separated from the vitreous 

 table, is supported by stout bony partitions, extended chiefly in 

 the transverse direction, and with an oblique and wavy course. 



