THE VOMER. 



55 



nasal fossa ; and at its base a third surface looks forwards and outwards into the 

 spheno-maxillary fossa. Its inner extremity touches the ala of the vomer. 



The two processes are separated by the deep spheno-palatine notch, which is 

 closed above by the body of the sphenoid, and thus converted into the foramen of 

 ihe same name. It leads from the spheno-maxillary fossa into the nasal cavity, and 

 transmits the internal nerves from Meckel's ganglion and the nasal branch of the 

 internal maxillary artery, with corresponding veins. 



Varieties. The groove of the posterior palatine canal is sometimes closed in below, so 

 that the opening on the palate is bounded solely by the palate bone. The spheno-palatine 

 notch may also be converted into a foramen by the union of the upper ends of the sphenoidal 

 and orbital processes ; or the foramen maybe double from the development of an intermediate 

 osseous bridge. The orbital process varies greatly in size ; its orbital surface is frequently 

 enlarged from the union with the palate bone of a portion of bone ossifying from a separate 

 centre, usually united with the ethmoid or sphenoid, and already described with the sphe- 

 noidal spongy bone (p. 45). The external accessory palatine canal is often wanting ; or it 

 may be placed between the palate and superior maxillary bones. 



THE VOMER. 



The vomer is a thin median bone, irregularly quadrilateral, and placed 

 vertically between the nasal fossae. It articulates with the sphenoid, ethmoid, 

 palate, and superior maxillary bones, and with the septal cartilage of the nose. 



The surfaces are smooth and in 

 the recent state covered by mucous 

 membrane ; each is traversed by a 

 faint groove running downwards 

 and forwards, and conducting the 

 naso-palatine nerve to the canal of 

 Scarpa. The superior border is by 

 far the thickest part of the bone, 

 and is divided into two spreading 

 alte, which fit under the body of the 

 sphenoid, receiving the rostrum into 

 the groove between them ; the edge 

 of each ala meets the vaginal process 



GROOVE OF NASO-PAL. NERVE 



Fig. 55.- VOMER, FROM THE RIGHT SIDE. 

 (Drawn by D. Grunn. ) 



of the sphenoid and the cphenoidal 



process of the palate bone. The anterior border, sloping downwards and forwards, 

 is grooved for the septal cartilage, and in the upper half is united by anchylosis on 

 one or both sides with the perpendicular plate of the ethmoid. 



The anterior extremity of the vomer forms a short vertical edge which fits in 

 behind the incisor crest of the maxillaries, and from the upper end of which a process 

 projects forwards in the groove of the crest, while from its lower end a point 

 sometimes projects downwards between the incisor foramina. The inferior border 

 articulates with the nasal crest of the maxillary and palate bones. The posterior 

 border, thin, smooth, and unattached, separates the posterior nares. 



THE MALAR BONE. 



The malar bone forms the most prominent part of the cheek, and separates 

 the orbit from the temporal fossa. It is quadrangular in shape, with the angles 

 directed vertically and horizontally. The outer surface is convex, and presents a 

 little below the centre a slight elevation called the malar tuber os ity ; above this is 

 the orifice of the malar canal. The inner surface is concave, and looks into the 



