CRANIAL NERVES OF CAECILIANS " 525 



and in its ganglionic relationships, this third element of the 

 facialis is beyond question lateral line in character. It passes 

 along the posterior dorsal border of the geniculate ganglion with- 

 out entering it, but does appear to exchange fibers with it. It 

 enters a small ganglionic mass on the posterior dorsal border of 

 the Gasserian ganglion (figs. 27, 44, gild.) and appears to become 

 ganglionated at once, as a few sections anteriorly it becomes a 

 compact strand, which is maintained during its course through 

 the Gasserian ganglion. 



In the larva of Ichthyophis the seventh nerve has a full lat- 

 eral-line complement. A lateralis root enters the dorsal part 

 of the acusticum. There are two distinct lateral-line ganglia on 

 the facialis ; the anterior of these, from which the rami ophthalmi- 

 cus superficialis and buccalis arise, lies dorsal to the Gasserian 

 ganglion; the other ganglion is situated at the posterior dorsal 

 bcrder of the Gasserian ganglion, in contact with the dorsolateral 

 border of the geniculate ganglion (fig. 30). 



The geniculate ganglion is a small oval-shaped structure, in 

 contact with the Gasserian ganglion anteriorly, but easily dis- 

 tmguished from it. Four groups of fibers leave it : a ramus pala- 

 tinus leaves its anterior end; a ramus hyomandibularis of motor 

 and visceral sensory fibers passes from it posteriorly; a sympa- 

 thetic element runs posteriorly, closely associated with the pre- 

 ceding, to unite with the sympathetic branch from the Gasser- 

 ian ganglion to form the main sympathetic trunk; fibers, their 

 character unknown, join the lateral-line strand dorsally. In 

 Dermophis the geniculate ganglion does not come in contact 

 dorsally with the Gasserian ganglion. 



2. The ramus Oalatinus VII 



This leaves the extreme anterior end of the geniculate ganglion 

 and then appears at the medial ventral border of the Gasserian 

 ganglion. In a section through the entrance of the trigeminal 

 root into the Gasserian ganglion (fig. 26) a distinct tract of fibers 

 is seen joining the ramus palatinus. From this point the ramus 

 palatinus supposedly contains somatic sensory as well as visceral 



