62 



BONES OF THE HEAD. 



very many cases it deviates from the middle line, and more frequently to the 

 left than to the right side. The concave side is that on which the ala of 

 the vomer is most intimately connected with the ethmoid. 



Fig. 53. 



23 



Fig. 53. VERTICAL SECTION OF THE ADULT SKULL IN AN ANTERO-POSTERIOR 

 PLANE, PASSING A LITTLE TO THE LEFT OF THE MIDDLE, SHOWING THE SEPTUM 

 NARIUM, &c. 4 



1, nasal bone; 2, perpendicular plate of the ethmoid bone, with olfactory foramina 

 and grooves at its upper part ; 3, vomer ; 4, nasal process of the right superior maxillary 

 bone, forming part of the wall of the right nasal fossa ; below this the anterior extremity 

 of the right inferior turbinated bone, and below that, at x , the fore part of the right 

 inferior meatus of the nose ; 5, crista galli ; 6, inner surface of the frontal bone ; 7, of 

 the parietal bone; 8, squamous part of the temporal, all these being marked by grooves 

 of cerebral convolutions and meningeal vessels ; 9, placed on the occipital bone below the 

 internal or anterior occipital protuberance ; 10, the posterior or external occipital pro- 

 tuberance; 11, placed on the condyloid process below the anterior condyloid foramen; 

 12, placed on the posterior surface of the petrous bone below the meatus auditorius 

 internus ; between 9 and 12 the groove of the right lateral sinus, crossing also the 

 raastoid bone ; 13, placed above the sella turcica and between the anterior and posterior 

 clinoid processes ; 14, part of the left frontal sinus, the figure being placed on the left 

 side of the septum, between the left and the right sinus ; 15, part of the left sphenoidal 

 sinus, the figure being placed on the septum of the sinuses ; 16, hard palate and alveolar 

 ai-ch the figure is placed near the lower opening of the posterior palatine canal, and the 

 grooves which extend forwards from it ; 17, anterior nasal spine; 18, section of the left 

 superior maxillary bone, and near the place to which the line points, the section of the 

 lower part of the anterior palatine canal ; 19, placed on the inner surface of the ramus of 

 the lower jaw, below the sigmoid notch, and above the inferior maxillary foramen ; 

 20, inner surface of the body of the jaw on the oblique or mylo-hyoid ridge ; 21, section 

 of the lower jaw, near the symphysis ; behind the symphysis, and between 21 and 22, 

 the mental or genioid spines ; 23, groove for the mylo-hyoid nerve. 



