THE SKELETON 35 
The cranium, thus formed of numerous originally independent 
ossifications, which may retain throughout life more or less of their 
individuality, or be all fused together, according to the species, the 
age, or even individual peculiarity, consists of a brain-case, or bony 
capsule for enclosing and protecting the brain, and a face for the 
support of the organs of sight, smell, and taste, and of those concerned 
in seizing and masticating the food. The brain-case articulates 
directly with the anterior cervical vertebra, by means of a pair 
of oval eminences, called condyles, placed on each side of the large 
median foramen which transmits the spinal cord. It consists of a 
basal axis, continuous serially with the axes or centra of the 
yn 
” 
Fic. 6.—Longitudinal and vertical section of the skull of a Dog (Canis familiaris), with 
mandible and hyoid arch. an, Anterior narial aperture; MT, maxillo-turbinal bone ; /T, ethmo- 
turbinal; Na, nasal; ME, ossified portion of the mesethmoid; CZ, cribriform plate of the 
ethmo-turbinal: Fr, frontal; Pa, parietal; IP, interparietal; SO, supraoccipital; Ex0, ex- 
occipital; BO, basioccipital; Per, periotic; BS, basisphenoid; Pt, pterygoid; AS, ali- 
sphenoid; OS, orbitosphenoid; PS, presphenoid; Pl, palatine; VO, vomer; M.x, maxilla; 
PMzx, premaxilla; sh, stylohyal; eh, epihyal; ch, ceratohyal; bh, basihyal; th, thyrohyal ; 
s, symphysis of mandible; cp, coronoid process ; cd, condyle; a, angle; id, inferior dental 
canal. The mandible is displaced downwards, to show its entire form; the * indicates the 
part of the cranium to which the condyle is articulated.1 
vertebrae, and of an arch above, roofing over and enclosing the 
cavity which contains the cephalic portion of the central nervous 
system (see Fig. 6). The base with its arch is composed of three 
segments placed one before the other, each of which is comparable 
to a vertebra with a greatly expanded neural arch. The hinder or 
1 This and many of the following figures in this chapter are taken from Flower’s 
Osteology of the Mammalia. 
