ANATOMY AND PHYSIOLOGY OF THE BRAIN 377 



stylomastoid foramen. It presents within the aque- 

 duct, near the hiatus Fallopii, a reddish enlargement, 

 the geniculate ganglion. Outside the cranium it 

 runs forward in the parotid gland, and divides behind 

 the ramus into the cervicofacial and temporofacial 

 divisions. In the parotid and vicinity the radiating 

 branches form the pes anserinus. 



The facial nerve supplies all the muscles of expres- 

 sion of the face. 



THE AUDITORY NERVE. The eighth or auditory 

 is the special nerve of the sense of hearing. Super- 

 ficially it appears at the lower border of the pons, 

 external to the facial. It has two roots one from the 

 inner side of and one from the front of the restiform 

 body. It runs to the internal auditory meatus with 

 the facial nerve, the two being separated by the pars 

 intermedia and the auditory artery. The nerve in 

 the meatus divides into a cochlear and a vestibular 

 branch, whose distributions within the ear are described 

 under the special sense of hearing. 



THE NINTH NERVE. The ninth or glossopharyngeal 

 arises superficially by several filaments from the 

 groove between the olivary and restiform bodies at 

 the upper part of the medulla; deeply through the 

 lateral tract to a gray nucleus in the floor of the 

 fourth ventricle. 



The nerve runs through the middle part of the jugular 

 foramen with the vagus and spinal accessory, in a 

 separate sheath, and here presents two successive 

 ganglionic enlargements, the jugular and the petrous 

 ganglia. Outside the cranium it passes between the 

 jugular vein and the internal carotid artery, descending 

 in front of the latter, and beneath the styloid process 

 and its muscles, to the lower border of the stylo- 

 pharyngeus, and supplies the mucous membrane of 

 the tongue. It then crosses this muscle and divides 

 into branches beneath the hyoglossus. In the jugular 



