40 ANATOMY OF THE HORSE. 



teeth; from which project inward Me ;jrt/a^z;/e processes belonging 

 to the same bone, joined by the palate bones above, and the pa- 

 latine processes of the anterior maxiUary hones below : these 

 parts, altogether, constitute the bony palate. The anterior third 

 of the palate takes the name of interdental space ; it is, in fact, a 

 longitudinally oval interval, which is incompletely filled by the an- 

 terior palatine processes. At the junction of the contributing por- 

 tions of the palate and maxillary bones to the palatine arch, oppo- 

 site and near to the last molar tooth, is the palato-maxillary fo- 

 ramen : from which takes its rise the palato-maxillary canal, 

 which courses the roots of the alveolar processes, and conducts an 

 artery of the same name forwards. Along the middle of the arch 

 runs the palatine suture, uniting the palate and superior and an- 

 terior maxillary bones of one side to tlieir fellows on the other. 

 At the external borders of the interdental space, formed by the 

 superior and anterior maxillary bones, are the alveolar cavities for 

 the tusks, commonly nearer by about one-third to the corner in- 

 cisive than to the first molar teeth. The symphysis of the superior 

 maxilla continued in a line from the palatine suture ; pierced by the 

 lower opening of the foramen incisivum, which is situated at the 

 roots of the anterior palatine processes, and gives passage to the 

 palato-maxillary arteries. The anterior maxillary surface is vaulted 

 in front, to extend the superficies of the palate. In conclusion, we 

 have the inferior alveolar processes, alveolar cavities, and inferior 

 surfaces and /aces of the incisive teeth. 



EACH LATERAL SURFACE INCLUDES— 

 1. The lateral cranial region, which is bounded, pos- 

 teriorly, by the occipital crest and condyloid process ; anteriorly, 

 by the orbit. It presents to observation — one side of the occipital 

 crest, descending to the base of the styloid process, whence a sharp 

 ridge extends from it to the zygomatic crest, which ridge forms 

 the inferior boundary of the temporal fossa. The external side of 

 the occipital styloid process, roughened from the attachment of 

 the stylo-maxillaris. The petrous portion of the temporal 

 bone, locked in between the squamous portion of the same and 

 the occipital bone, comprising — the mastoid process, in apposition 

 with the base of the occipital styloid process behind, and with 

 the descending plate of the squamous portion in front. Within a 

 circular space formed by this plate behind, and the anterior mas- 

 toid process before, protrudes the auditory process, to which is 

 attached the external ear: it is perforated by the meatus audito- 

 rius externus, whose orifice is expanded or trumpet-shaped. 

 'The temporal zygomatic process is continuous, posteriorly and 

 inferiorly, with the anterior mastoid ; at which part its surface is 

 excavated to make room for the attachment of the external ear ; 



