////: \ .i> i/. GAVITDK 443 



bne: it is tin; mirn -.vest. The mulilli; comprised between the two tur- 

 hinated bones. presents, on arriving near the ethmoidal cells, the orifice 

 which briiiLTs all the sinuses into communication with the nasal fossa. This 

 oriticr is onlinarily narrow and curved; but we have seen it sometimes 

 converted into a foramen sufficiently wide to permit the introduction of a 

 tinker end. It is also by this ineatus that the inferior compartment of tin- 

 turbinated bones opens into the nasal fossa, these two bones being each 

 rolled in a contrary direction. .The inferior meatus, situated under the 

 maxillary turbinated bone, is not distinct from the floor of the nasal cavity. 

 See figure 224 for the arrangement of the turbiuated bones and the meatuses 

 on the external wall of the nose. 



Roof or arch. This is formed by the nasal bone, and is only a narrow 

 channel, confounded, as has been said, with the superior meatus. 



Fl<: Wider, but not so long as the roof, which is opposite to it, but 

 from which it is distant by the height of the cartilaginous septum, the floor 

 is concave from side to side, and rests on the palatine arch, which separates 

 tin- mouth from the nasal cavities. 



In front of this nasal region is remarked the canal or organ of Jacobson : 

 a short duct terminating in a cul-de-sac in the middle of the cartilaginous 



Fig. 224. 



.Ill IHNU. MI.I>1\N >..' I ION 01 1111. Ill .VI' AM' I rl'l.l: I'AKl 



1. 1, Atla.>: .', 2, Dentata ; II, Trachea; 4, Right ;.tyl..-thyri<l.-ii> : "', <iutturnl 

 |K>iu'h : ;, Styln-|.li;ir_>:. I'-ilato-pharynijiMis : '', Sphenoidal sinus; 1". 



i rjivity ; 11, Oi.iput; !'_', Parietal protuberance; 13, Frontal MMII- : 

 14, Kthnmiilal turbinated bone; 15, Maxillary turbinateil bone: HJ, Kiitr.i 

 nostril; is, Pharyngeal cavity; 19, Inferior maxilla; -'. l'r.-ina\ill:i : Jl, 

 H.-ird palate. 



substance which closes the incisive foramen. At the bottom of this ,-nl-il,- 



tac opens a second canal, longer, wider, and more remarkable, but which 



I y.-t 1>. i n il scrilmd. (It has be i-ed by Stenson, and is named 



icon's dud.") It has KOIIH tinn s the diameter of a writing quill, 



commences by a rul-de-sac on a level with the second molar tooth, accom- 



panies the ind ri"r border of the vomcr from behind to before, where it is 



i'-ped in a kind of cartilaginous sheath a dependency of the nasal 



-i I'tuni : it terminates, as we have said, after a conrs. i,f about ." incln -. 



