182 ELEMENTARY BIOLOGY. [XIII. 



7. The Faciales 



take their origin from the floor of the hind -brain, 

 behind the fifth and in common with the eighth; and, 

 leaving the hind-brain, enter into close connexion with 

 the Gasserian ganglion. Each then divides into two 

 branches, an anterior and a posterior. The anterior 

 passes into the palatine division of the fifth ; the 

 posterior passes between the dorsal and ventral crura 

 of the suspensorium, enters the tympanic cavity, 

 runs over the columella auris and then, as it leaves 

 the tympanum, receives a very large branch from the 

 glossopharyngeal. Finally it divides into two branches, 

 anterior and posterior. 



a. The former, which answers to the chorda tympani 

 of the higher Vertebrata, runs along the inner 

 face of the ramus of the mandible parallel with 

 the mandibular branch of the fifth. 



I. The posterior passes alongside the cornu of the 

 hyoid and supplies its muscles. 



8. The Auditorii 



arise in common with the foregoing. Each divides 

 into two branches which enter the auditory capsule. 



The Post-auditory nerves are : 



9. The Glossopharyngei. 



These nerves arise, in common with the next, from 

 the medulla oblongata; and the roots of both leave 

 the skull by an aperture behind the auditory capsule 

 on each side, and form a common ganglion. From 

 this the trunk of the glossopharyngeal is given off. 

 It passes downwards and forwards to the root of the 



