BONES OF THE SKULL. 



123 



(13); this plate, being pierced with numerous holes for their 

 transit ; the cavity of the nose is further increased by commu- 

 Fig. 94. Fig. 95. 



IS 13 



Partition of Nostrils. Transverse vertical section of Orbits, 



Nostrils, and Palate. 



nications established between it and the sinuses existing 



in the frontal and superior max- Fig. 96. 



illary bones, and which are lined 



by a continuation of the nasal u 1 



membrane. 



Fig. 96 shews the lateral boun- 

 dary of the nose, and the passages 

 leading to and from the frontal 

 and maxillary sinuses. 









,P- 

 Lateral boundary. 



[ 248. Fig. 97. THE CEBITS (10) 

 are two deep conical cavities, with 

 their base directed outwards ; they are destined to lodge and 

 protect the eyes. Thereof of the or- Fig- 97. 



bit is formed by a thin plate of the 

 frontal bone (fig. 81, 18); the 

 floor chiefly by the superior max- 

 illary (11), the internal wall by the 

 ethmoid and lachrymal (3,4) ; the 

 latter bone is grooved for the passage 

 of the nasal duct(l 1 ), which conveys 

 the tears into the nose ; the external 



