46 CONSIDERATIONS OF THE BRAIN OR ENCEPHALON. 



salivary nucleus (the dorsal part of the facial nucleus) in the 

 pons. They issue from the transverse ponto-medullary groove 

 between the facial and auditory nerves (apparent origin) at the 

 point where the afferent fibers enter the brain. The sensory 

 part of the intermediate nerve, which is the nerve of taste to the 

 anterior part of the tongue, takes its origin in the ganglion geniculi 

 situated within the canalis facialis (Follopii); its apparent central 

 termination is in the ponto-medullary groove. 



8. The acustic nerve (n. acusticus] is a sensory nerve, having 

 the double function of hearing and equilibrium (Figs. 21, 44 

 and 45). It rises from the spiral and vestibular ganglia situated 

 in the petrous bone, and its apparent central termination is in the 

 bottom of the transverse groove separating the pons from the 

 medulla. The roots of both the seventh and eighth nerves are 

 near the upper end of the posterior lateral sulcus of the medulla 

 oblongata. 



9. Glossopharngeal Nerve. (N. glossopharyngeus}. This 

 is a complex mixed nerve, containing efferent -fibers (motor, vaso- 

 dilator, secretory and trophic) and afferent fibers, which are both 

 common sensory and gustatory. It is joined to the medulla in 

 the bottom of the superior end of the posterior lateral sulcus 

 (Figs. 21 and 45). This point of attachment is the apparent 

 origin of its efferent and the apparent central termination of its 

 afferent fibers. The latter fibers rise in the superior and petrosal 

 glossopharyngeal ganglia situated in the jugular foramen. The 

 genetic nucleus of the efferent fibers is located inside the medulla. 



Behind the ninth nerve in the same groove are the roots of the 

 tenth and eleventh nerves. The roots of the ninth and tenth 

 are situated between the olive and the restiform body; but, if the 

 nerve trunks have been cut, it is impossible to determine which 

 of the ten or a dozen root bundles belong to each of them. 



10. The Vagus Nerve. (N. vagus}. The efferent -fibers of the 

 vagus, like the glossopharyngeal, take their apparent origin from 

 the posterior lateral sulcus, and in the same sulcus the afferent 

 fibers enter the medulla, apparent central termination (Figs. 21 

 and 45). It is a very complex nerve. Its efferent fibers comprise 

 motor, inhibito-motor, vasodilator, secretory, trophic and inhibito- 



