82 



THE SKELETON. 



it is traversed by a longitudinal groove (sometimes 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. The infer/or 



Nasal bone 

 Nasal proc 



Lachrymal bone. 



-Orbital surface. 

 Infra-orbital 



groove. 



Infra-orbital 

 foramen. 



Ant. nasal spine 



Artie, with titular. 



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. 



Older 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. 



