82 



THE SKELETON. 



it is traversed by a longitudinal groove (sometinles a canal), for. the passage 

 of a branch of the nasal nerve. The superior border is narrow, thick and 

 serrated, for articulation with the nasal notch of the frontal bone. 



Nasal bone. 

 Nasal proc. 



Infra-orbital 

 foramen. 



Ant. nasal spine. 



Alveolar 

 process 



Lachrymal bone. 



Orbital surface. 

 Infra-orbital 

 groove. 



Artie, with malar. 



> \Post. dental 

 canals. 



Maxillary 



tiiberosity. 



With frontal bone. 



With 

 'opposite bone. 



FIG. 46. Nasal and lachrymal bone in situ. 



border is broad, thin, sharp, inclined obliquely downward, outward, and back- 

 ward, and serves for the attachment of the lateral cartilage of the nose. This 

 border presents, about its middle, a notch, through which passes the branch of the 

 nasal nerve above referred to, and is prolonged at its inner extremity into a sharp 



spine, which, when articulated 

 with the opposite bone, forms 

 the nasal angle. The external 

 border is serrated, bevelled at 

 the expense of the internal sur- 

 face above and of the external 

 below, to articulate with the 

 nasal process of the superior 

 maxillary. The internal bor- 

 der, thicker above than below, 

 articulates with its fellow of 

 the opposite side, and is pro- 

 longed behind into a vertical 

 crest which forms part of the 

 septum of the nose ; this crest articulates above downward with the nasal spine 

 of the frontal above, and the perpendicular plate of the ethmoid, and the trian- 

 gular septal cartilage of the nose. 



Development. By one centre for each bone, which appears about the eighth 

 week. 



Articulations. With four bones : two of the cranium, the frontal and ethmoid, 

 and two of the face, the opposite nasal and the superior maxillary. 



Attachment of Muscles. A few fibres of the Occipito-frontalis muscle. 



Outer Surface. 

 FIG. 47. Right nasal bone. 



With 

 frontal spine. 



- Crest. 



With 



^perpendicular 

 plate of 

 ethmoid. 



Groove, for nasal nerve. 



Inner Surface. 



FIG. 48. Left nasal bone. 



