52 AMPHIBIA. 



1. Olfactory nerve. 



2. Optic nerve. 



3. Third or common oculo-muscular nerve, arising behind the mammillary 



eminence in the track of the pyramidal body ; it gives a branch to join one 

 from the first trunk of the fifth to form ciliary nerves, and then gives a 

 branch to the levator, depressor, adductor, and inferior oblique muscles of 

 the eye. 



4. Fifth or trigeminal nerve, arising in the track of the restiforrn body. 



5. Sixth nerve given to the abducent muscle, and those which encircle the optic 



nerve, and are spread on the convex portion of the sclerotic coat of the eye. 



6. Hard portion of the seventh, arising from the restiform body; it crosses the 



external auditory meatus to give filaments to a muscle inserted into the angle 

 of the jaw, and then passes to terminate on the constrictor muscle of the 

 throat, which resembles in some degree the cutaneous muscle in the human 

 subject ; it communicates with branches of the cervical nerves given to the 

 lower portion of the same muscle, and these are composed of filaments 

 derived from both the anterior and posterior surfaces of the spinal cord. 



7. Auditory nerve, arising from the restiform body ; it divides into two principal 



branches : the anterior passes to the termination of the anterior upright and 

 - horizontal semicircular canals ; the other is spread on the sack of the 

 labyrinth, after sending a branch to the termination of the posterior upright 

 and the horizontal semicircular canals. 



8. Glosso-pharyngeal nerve, arising from the restiform body ; it passes under- 



neath the cavity containing c the sack of the labyrinth, gives filaments to 

 muscles connected with the lingual bone, and terminates in the membrane of 

 the pharynx. 



9. Trunk of the par vagum, arising from the restiform body, and sending a 



filament to communicate with the auditory nerve on the sack of the 

 labyrinth. 



10. Ninth or hypo-glossal nerve, arising near the situation of the pyramidal bodies 

 by two or three roots ; it divides into an anterior and posterior trunk : the 



