Kingsbury, Brahi of Nectufus. 



191 



utterly to trace the fibers to their nidus of origin in the base of 

 the brain. The distribution of a portion at least of the fibers 

 to the metaplexus has been noted before ; nothing in the char- 

 acter of a terminal nidus was observed. 



The oculomotor (III) enters the brain at the level of the 

 mesencephalic pit and passes dorsad to its nidus in close rela- 

 tion to the posterior longitudinal fasciculus. Several large 

 ganglion cells occur cephalad of this point at about the region 

 of transition from mesencephal to diencephal, which Osborn 

 regarded as constituting a portion of the oculomotor nidus, and 

 also as having a relation to the fibers of the postcommissure. 

 With Burckhardt, however, I must consider the relation of these 

 cells to the post-commissure as of no significance, and regard as 

 doubtful any direct connection of these with oculomotor fibers. 



The undeveloped condition of the optic nerves has been 

 commented on. The decussation of the fibers appears com- 

 plete, the fibers all proceeding dorsad and caudad upon the ectal 

 surface of the brain to the mesencephal. 



The cranial nerves of Necturus cephalad of the tenth 

 that have been more especially studied may be tabulated as 

 follows : 



*This, of course, is only stated inferentialiy, since no experiments have 

 been made to determine it empirically. In general, those roots springing from 



