THE HEAD, ANTERIOR. 



35 



It will be found to extend from the foramen caecum in 

 the frontal bone over the convexity of the head in the mid- 

 dle line, and at the base of the falx cerebri (as will be ap- 

 parent later), to terminate in a considerable cavity opposite 

 the external occipital protuberance, called the torcular 

 Herophili, or the confluence of sinuses ; or it may pass into 



Diag. i. A DIAGRAM OF THE SINUSES OF THE SKULL, VERTICAL-ANTERO-POSTE- 

 RIOR. (/. 5. H,)i t Superior longitudinal. 2, Inferior longitudinal. 3, Straight. 4, 

 Lateral. 5, Cavernous. 6, Superior petrosal. 7, Inferior petrosal. 8, Internal jugu- 

 lar vein, formed below the skull by the junction of the inferior petrosal and lateral 

 sinuses. 9, Right and left veins of Galen. 10, Common vein of Galen, n, Occipital. 

 12, Foramen magnum. 13, Jugular foramen. 



the right lateral sinus (usual). By the scissors this sinus is 

 to be laid open from its beginning to its ending. The bands 

 crossing the sinus are the chordae Willisii. Its tributaries 

 are the nasal veins (sometimes) through the foramen caecum, 

 the parietal through the parietal foramen, the superior cere- 



