THE NERVES. 395 



1. N. cochlea, passes through the anterior foramen with spirally- 

 arranged fibres, becoming the more so as they approach themodiolus, 

 sending its branches through the tractus spiralis foraminulentus, 

 which form loops upon the lamina spiralis, and terminate at the 

 infundibulum. 



2. N. vestibuli, passes backwards and divides into three branches 

 which go through three fossse to the vestibule. A grayish-red en- 

 largement is found on it, like the auditory nerve which is generally 

 rather reddish. 



a. N. saccularis major, passes obliquely forwards to the superior 

 fossa and its canaliculi into the saccus oblongus and the ampulla 

 of the superior and external semicircular canals. 



b. N. saccularis minor, more horizontal to the saccus hemi- 

 sphericus. 



c. N. ampullaris inferior, deeper, through the external fossa to 

 the ampulla of the posterior semicircular canal. 



641. IX. N. glosso-pharyngeus. 



Origin : with a series of filaments (two roots) from corp. resti- 

 forme, above n. vagus, below n.facialis; passing out between corp. 

 restiforme and olivare. Course : the trunk passes, a distance of from 

 one half to three quarters of an inch outwards, forwards and rather 

 upwards to the anterior part of foram. jugulare, separated from the 

 n. vagus by a vessel, forms two ganglia, passes out from the cranial 

 cavity, and divides into two branches. Situation : in iheforam. 

 jugulare ; in front and above, before n. vagus and accessorius, 

 before and on the inner side of v.jugularis interna, in a canal of 

 dura mater ; below the foramen : united with a ramus of n. sym- 

 pathicus, curved forwards and downwards on the outer surface of 

 carotis interna, on the internal of m. stylo-pharyngeus, removed 

 from v.jugularis int., n. accessorius and vagus. Junctions : with 

 n. vagus, its auricular and pharyngeal branch with plexus caroticus; 

 and with n.facialis in the m. digastricus. 



1. Ganglion jugulare (Ehremitter, J. Miiller), lies (from a half 

 to one line long and broad) upon the posterior fasciculus ofgtosso- 

 pharyngeus, the anterior and posterior roots of which unite above 

 and below it, in the superior part of the foram. jugulare. Below 

 it (from two to four lines) lies a larger ganglion. 



2. Ganglion petrosum (Andersch). It is oval, one and a half 

 to two lines long, situated in the vellecula of the petrous bone, and 

 receives on its superior and anterior part : 



Nerv. tympanicus s. Jacobsonii. The tympanic nerve ascends 

 by means of a peculiar canal (upon the crest between canal caro- 



