THE ANTERIOR REGIOX OF THE SKULL. 



221 



foss;\:> communicate, and it is often bent considerably to one side. 1 It is formed, in 

 front, by tbe crest of tbe nasal bones and nasal spine of tbe frontal ; in the middle, 

 bv the perpendicular plate of the ethmoid : behind, by the vomer, rostrum and eth- 

 moidal crest of the sphenoid; belo\v. by the crests of the superior maxillary and 

 palate bones It presents, in front, a large, triangular notch, which receives the tri- 

 angular cartilage of the nose ; and behind, the guttural edge of the vomer. Its 

 surface is marked by numerous vascular and nervous canals and the groove for 



Crest of nasal bone. 



Xasal .opine of_ 

 frontal bone. 



for triangular^ 

 cartilage of septum 



.Crest of palate bone, 

 est of superior maxillary 

 bone. 



FIG. 177. Inner wall of nasal fossae, or septum of nose. 



the naso-palatine nerve, and is traversed by sutures connecting the bones of which 

 it is formed. 



The outer wall (Fig. 176) is formed, in front, by the nasal, the nasal process 

 of the superior maxillary and lachrymal, bones ; in the middle, by the ethmoid 

 and inner surface of the superior maxillary and inferior turbinated bones ; behind, 

 by the vertical plate of the palate bone and the internal pterygoid plate of the 

 sphenoid. This surface presents three irregular longitudinal passages, or meatuses, 

 formed between three plates of bone that spring from it ; they are termed the 

 superior, middle, and inferior meatuses of the nose. The superior meatus, the 

 smallest of the three, is situated at the upper and back part of each nasal fossa, 

 occupying the posterior third of the outer wall It is situated between the superior 

 and middle turbinated bones, and has opening into it two foramina, the spheno- 

 pfilatine at the back of its outer wall, and the posterior ethmoidal cells at the front 

 part of the outer wall. The opening of the sphenoidal sinus is at the upper and 

 back part of the nasal fossa immediately behind the superior turbinated bone and 

 into a groove, the spheno-ethmoMal recess. The middle meatus is situated between 

 the middle and inferior turbinated bones, and occupies the posterior two-thirds of 

 the outer wall of the nasal fossa. It has two apertures : in front that of the inftin- 

 dibulum, by which the meatus communicates with the anterior ethmoidal cells, 

 and through these with the frontal sinuses ; near the centre is the orifice of the 

 ant mm. which varies somewhat as to its exact position in different skulls. The infe- 

 rior meatus. the largest of the three, is the space between the inferior turbinated 



1 See footnote, p. 185. 



