378 NERVOUS SYSTEM. 
as before described (page 347). It passes into the internal 
auditory meatus and is distributed to the internal ear within 
the petrous bone. 
IX. N. GLOSSOPHARYNGEUS (Fig. 156, a —The ninth or 
glossopharyngeal nerve takes origin (Fig. 138, X) from the. 
side of the medulla, as described in the account of the brain. 
Close to its origin its trunk bears a small enlargement, the 
ganglion superius. It‘ passes along with the tenth and 
eleventh nerves through the jugular foramen. At its exit it 
has a ganglionic enlargement, the ganglion petrosum; this is 
connected by fine fibres with the ganglion nodosum (Fig. 156, 
@) of the vagus. The glossopharyngeal (Fig. 156, @) then 
passes craniad over the surface of the tympanic bulla (45) and 
mediad of the digastric muscle. It continues mediad of the 
carotid artery, and as it approaches the cranial cornu of the 
hyoid divides into two portions, one of which passes to the 
muscles and mucosa of the pharynx, and the other to the 
tongue, where it is the special nerve of taste. 
X. N. vaGus.—The vagus frierve arises from the side of 
the medulla in the manner described under the Brain, (page 
346 and Fig. 138, XY). It passes through the jugular foramen 
along with the glossopharyngeal and accessory nerves. 
Cervical Portion of the Vagus (Fig. 156, d, @’).—In the 
foramen, or just before entering it, it presents a ganglionic 
enlargement, the ganglion jugulare (or ‘‘ganglion of the 
toot’’), and a short distance beyond the foramen it forms a 
second ganglion, the ganglion nodosum (2) (or ‘‘ ganglion of 
the trunk’’), which lies dorsocaudad of the superior cervical 
sympathetic ganglion (¢). The ganglia of the vagus and sym- 
pathetic are closely bound together by connective tissue, and 
that portion of the vagus craniad of the ganglion nodosum is 
interconnected by a network of nervous fibres with the sym- 
pathetic (¢), hypoglossal (4), and accessory (c) nerves. From 
the ganglion nodosum the vagus (d@’) passes caudad, closely 
bound up with the sympathetic; the two lie at the side of the 
common carotid artery. Just before entering the thorax the 
two separate, the vagus being the larger and lying ventrad of 
