174 blDWARD PHELPS ALLIS, JUN. 



an important branch which would seem to very probably 

 represent its most auterior section was found turning back- 

 ward around the anterior end of the sac. 



The remainder of the maxillaris then continues forward, 

 lying at first ventro-lateral to the median section of the 

 infra-orbital canal, and then directly internal, and hence 

 dorsal, to the more anterior part of the same canal. It is 

 there distributed to the general tissues of the region. 



Ramus Mandibularis Trigemini. 



The ramus mandibularis or maxillaris inferior trigemini 

 arises from the trigeminal part of the trigemino-facial 

 ganglion as part of a short truncus trigemini which im- 

 mediately separates into maxillaris and mandibularis portions. 

 The ramus mandibularis immediately runs laterally downward 

 and forward, ventral to the ramus buccalis, and acquires a 

 position postero-lateral to the latter nerve, there forming the 

 postero-lateral portion of the large. Hat, truncus buccalis- 

 maxillo-mandibularis. 



At or before the ramus mandibularis thus separates from 

 the ramus maxillaris, and while the truncus trigemini is still 

 ganglionic, a large branch is given off from its posterior 

 aspect. Turning laterally upward and backward, it passes 

 dorsal to the posterior carotid artery, immediately anterior 

 (distal) to the orbital branch of the arteiy, and then passes 

 upward along the lateral aspect of the facial part of the 

 trigeuiino-facial ganglion, here being partly imbedded in the 

 ganglion. It passes dorsal to the ramus palatinus facialis, 

 accompanied by the orbital branch of the posterior carotid. 

 Dorso-posterior to the trigemino-facial ganglion it lies ventro- 

 lateral, and then lateral or antei'O-lateral to the truncus 

 hyoideo-mandibularis facialis, accompanying the truncus in 

 its course, and lying, with it, at first along the mesial surface 

 of the hind end of the peri-orbital sinus, and then ventral 

 to that posterior prolongation of the sinus that goes back- 

 ward to join the jugular vein. This posterior prolongation 



