[Illustration: FIG. 61.--SKULL OF THE PIG: LEFT LATERAL ASPECT. 1, Occipital bone; 2, condyle of the occipital; 3, jugular process; 4, parietal bone; 5, parietal crests; 6, frontal bone; 7, orbital process; 8, orbital cavity; 9, external auditory canal; 10, zygomatic process; 11, superior maxillary bone; 12, intermaxillary or incisor bone; 13, nasal bone; 14, anterior orifice of the cavity of the nasal fossæ; 15, malar bone; 16, lachrymal bone; 17, inferior maxillary bone; 18, condyle of the inferior maxillary bone; 19, incisor teeth; 20, canine teeth; 21, molar teeth.] In the bear, the anterior margin of the frontal bone is prolonged by two small tongues of bone, which, descending on the lateral borders of the nasal bones, articulate with the superior half of the latter. The temporal bone is, as in man, furnished with a squamous portion, from which springs the zygomatic process, which is directed towards the face, to terminate in the following manner: in the carnivora, the pig, and ruminants, it articulates with the malar bone by its inferior border; in the horse, it insinuates itself as a sort of wedge between the malar bone and the orbital process of the frontal bone, with which it articulates, as we have already pointed out, and contributes, by a portion situated in front of this articulation, to form the boundary of the anterior opening of the corresponding orbital cavity. As in man, the zygomatic process arises by two roots: one, transverse, behind which is situated the glenoid cavity of the temporal bone; the other, antero-posterior, which proceeds to join above with the superior curved line of the occipital bone. Behind the glenoid cavity is found the external auditory canal, and, further back still, the mastoid process. This latter, but slightly developed in the carnivora, a little more so in the ruminants, and still more in the horse, has its external surface traversed by a crest, _the mastoid crest_, which, after becoming blended with the antero-posterior root of the zygomatic process, proceeds with this latter to join the superior occipital curved line. Below the auditory canal is situated a round prominence, highly developed in carnivora; this is _the tympanic bulla_, also called _the mastoid protuberance_; it is an appendage of the tympanum. The Face