162 THE SKELETON. 



the facial and zygornatic surfaces. A small part of the Masseter muscle arises 

 from this process. 



The Nasal Process is a thick triangular plate of bone, which projects up- 

 wards, inwards, and backwards, by the side of the nose, forming part of its 

 lateral boundary. Its external surface is concave, smooth, perforated by 

 numerous foramina, and gives attachment to the Levator Labii Superioris, 

 Alaeque Nasi, the Orbicularis Palpebrarum, and tendo oculi. Its internal 

 surface forms part of the outer wall of the nose ; it articulates above with the 

 frontal, and presents a rough uneven surface, which articulates with the eth- 

 moid bone, closing in the anterior ethmoid cells; below this is a transverse ridge, 

 the superior turbinated crest, for articulation with the middle turbinated bone 

 of the ethmoid, bounded below by a smooth concavity, which forms part of 

 the middle meatus ; below this again is the inferior turbinated crest (already 

 described), for articulation with the inferior turbinated bone; and still more 

 inferiorly, the concavity which forms part of the inferior meatus. The an- 

 terior border of the nasal process is thin, directed obliquely downwards and 

 forwards, and presents a serrated edge for articulation with the nasal bone : its 

 posterior border is thick, and hollowed into a groove for the nasal duct: of 

 the two margins of this groove, the inner one articulates with' the lachrymal 

 bone, the outer one forms part of the circumference of the orbit. Just where 

 the latter joins the orbital surface is a small tubercle, the lachrymal tubercle; 

 this serves as a guide to the surgeon in the performance of the operation for 

 fistula lachrymalis. The lachrymal groove in the articulated skull is con- 

 verted into a canal by the lachrymal bone, and lachrymal process of the in- 

 ferior turbinated ; it is directed downwards, and a little backwards and out- 

 wards, is about the diameter of a goose-quill, slightly narrower in the middle 

 than at either extremity, and lodges the nasal duct. 



The Alveolar Process is the thickest and most spongy part of the bone, 

 broader behind than in front, and excavated into deep cavities for the reception 

 of the teeth. These cavities are eight in number, and vary in size and depth 

 according to the teeth they contain. That for the canine tooth is the deepest ; 

 those for the molars are the widest, and subdivided into minor cavities ; those 

 for the incisors are single, but deep and narrow. The Buccinator muscle arises 

 from the outer surface of this process, as far forward as the first molar tooth. 



The Palate Process, thick and strong, projects horizontally inwards from the 

 inner surface of the bone. It is much thicker in front than behind, and forms 

 a considerable part of the floor of the nostril, and the roof of the mouth. Its 

 upper surface is concave from side to side, smooth and forms part of the floor 

 of the nose. In front is seen the upper orifice of the anterior palatine (incisor) 

 canal, which leads into a fossa formed by the junction of the two superior 

 maxillary bones, and situated immediately behind the incisor teeth. It trans- 

 mits the anterior palatine vessels, the naso-palatine nerves passing through the 

 intermaxillary suture. The inferior surface, also concave, is rough and uneven, 

 and forms part of the roof of the mouth. This surface is perforated by 

 numerous foramina for the passage of nutritious vessels, channelled at the 

 back part of its alveolar border by a longitudinal groove, sometimes a canal, 

 for the transmission of the posterior palatine vessels, and a large nerve, and 

 presents little depressions for the lodgment of the palatine glands. This sur- 

 face presents anteriorly the lower orifice of the anterior palatine fossa. In 

 some bones, a delicate linear suture may be seen extending from the anterior 

 palatine fossa to the interval between the lateral incisor and the canine tooth. 

 This marks out the intermaxillary, or incisive, bone, which in some animals 

 exists permanently as a separate piece. It includes the whole thickness of the 

 alveolus, the corresponding part of the floor of the nose, and the anterior nasal 

 spine, and contains the sockets of the incisor teeth. The outer border of the 

 palate process is incorporated with the rest of the bone. The inner border is 

 thicker in front than behind, and is raised above into a ridge, which, with the 



