THE SKULL AS A WHOLE. 139 
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and posterior series of broader folds, which together constitute the 
ethmoturbinal. In the rabbit, as in mammals generally, the 
latter is divisible into a more dorsal elongated portion attached 
to the nasal bone, the nasoturbinal, and a more ventral portion, 
also posterior portion, the ethmoturbinal proper, composed of 
several shorter folds decreasing in length from above downward. 
In the natural condition the turbinated bones bear a considerable 
portion of the nasal epithelium, the surface of which is greatly 
increased by the folding of the underlying bone. That covering 
the ethmoturbinal contains the olfactory sense organs, while that 
covering the maxilloturbinal is non-sensory and possesses the 

Fic. 63. lLateralsurface of the left half of the mandible: a.m. 
angle; c.m., body of mandible; cp.m., articular portion (head) 
of mandible; d.i., d.m., and d.pm., incisor, molar and premolar 
teeth; f.m., mental foramen; i.m.a. and i.m.p., anterior and 
posterior mandibular incisures; p.c., coronoid process; p.cd., 
condyloid process; t.m. and t.pt., masseteric and pterygoid 
tuberosities. 
mechanical function of freeing the air of the respiratory tracts from 
foreign materials, as well as of warming it slightly in its passage. 
On this account the respective structures are conveniently distin- 
guished as sensory (olfactory) turbinals and respiratory 
turbinals. 
The mandible (mandibula) is composed of two portions, united 
anteriorly by the symphysis mandibulae. Each half comprises 
a horizontal portion, forming in conjunction with that of the oppo- 
site side the body of the mandible (corpus mandibulae), and a 
posterior, vertical portion, the ramus mandibulae, the latter 
serving for the insertion of the muscles of mastication and for 
articulation with the skull. The body of the mandible bears on its 
