BOXES OF THE CRANIUM. 



191 



FIG. 43 A 



FIG. 43 B j 



noid cells. The 

 anterior are more 

 numerous and 

 larger; they open 

 into the middle 

 meatus, and one 

 of the most an- 

 terior cells forms 

 a kind of infun- 

 dibulum which 

 opens above into 

 the frontal si- 

 nus, and ends 

 below in front 

 of the maxilla- 

 ry sinus or an- 

 trum Highmori- 

 anum. The pitu- 

 itary membrane 

 extends from the 

 nose, and lines 

 the whole of the 

 cells. Its struc- 

 ture is mostly 



compact, consisting of very thin brittle plates of bone; the 

 spongy tissue is found in the crista-galli and turbinated 



FIG. 43, A represents cerebral surface of the Sphenoid Bone. 1 1 Lesser 

 wings or alae minores. 2 2 Upper extremity of greater wings. 3 ^Ethmoid 

 spine. 4 Optic foramen. 5 Anterior clinoid process. 6 Posterior clinoid. 

 7 Sphenoidal fissure or foramen lacerum anterius. 8 Foramen rotundum. 9 

 Foramen ovale. 10 Foramen spinale. 11 Styloid process. 12 External 

 pterygoid process. 13 Internal pterygoid process. 14 Pterygoid foramen. 15 

 Articular surface for cuneiform process of occiput. 16 Sella turcica. 



FIG. 43, B represents the anterior and inferior surface of the Sphenoid, a a 

 Lesser wings of ingrassias. 6 6 Greater wings, c jEthmoidal spine, d Azygos 

 process, e e Sphenoidal cells. // Posterior clinoid processes, g g Sphenoidal 

 fissure, h h Foramen rotundum. i i Cavities for the middle lobes of the 

 cerebrum, j j Surface for the temporal muscle, k k Styloid process. I I 

 External pterygoid process, m m Internal pterygoid process, n Pterygoid 

 foramen, o o Articular surface for the frontal bone, p Sella turcica. 



