Head and Neck. 405 



These Emissary Veins are as follows, viz.: (1) 

 One, occasionally present, passing through the foramen 

 caecum and connecting the anterior end of the longitudinal 

 sinus with the nasal veins; (2) another, passing through 

 'the mastoid foramen between the lateral sinus and the 

 posterior auricular vein; (3) a third, through the parietal 

 foramen between the longitudinal sinus and the veins of 

 the scalp; (4) a fourth, connecting the cavernous sinus, 

 through the ophthalmic vein, with the supra-orbital and 

 the angular veins; (5) veins passing through foramina 

 at the base, viz., one, through the anterior condyloid fora- 

 men, connecting the occipital sinus internally, with the deep 

 veins of neck externally; another, through the posterior 

 condyloid connecting the lateral sinus with the deep veins 

 of neck. In addition to these, there are a few small veins 

 passing through the foramen ovale, the foramen lacerum 

 medium and the foramen Vesalii, which connect the ca- 

 vernous sinus with the pterygoid and the pharyngeal plex- 

 uses of veins, and these plexuses communicate with the 

 facial vein in the following manner, viz. : The pterygoid 

 toy means of the deep facial, which passes downwards 

 and forwards between the buccinator and the masseter 

 muscles to end in the facial vein ; and the pharyngeal by 

 emptying into the termination of the common facial vein. 

 Lastly, there is, to a slight degree, a direct connection be- 

 tween the veins of the pericranium and the ven- 

 ous channels of the diploe by means of minute openings 

 in the outer table of the skull. These emissary 

 veins may possibly serve a useful purpose by permit- 

 ting a free escape of blood from the sinuses when the lat- 

 ter are over-distended, especially in infancy during fits O'f 

 passion, etc, but they are of especial importance in con- 

 nection with pathological processes, offering as they do, 

 [direct channels for the spread of septic processes from 



