420 JOH^ H. STOKES 



The ascending tract of the spinal vestibular runs a compara- 

 tively short course from the bifurcation, beginning almost at 

 once to break up into its component parts for distribution. Some 

 strands continue horizontally forward into the substance of the 

 superior nucleus. Another portion breaks up in Deiter's nucleus. 

 A large number of strands, however, turn abruptly upward in a 

 vertical direction, forming a flattened column in a depression in 

 whose lateral surface lies the upper and outer part of Deiter's 

 nucleus. The posterior and medial fibers of this column fill the 

 notch separating the anterior extensions of the two cochlear nuclei. 

 On reaching the level of the nucleus fastigii in the base of the 

 cerebellum, these fibers, in company with others forming the nu- 

 cleo-cerebellar tract, bend sharply medially and spread out hke a 

 fan into the nuclear masses of the base of the cerebellum, a well- 

 defined portion participating in a decussation with fibers from the 

 opposite side. This decussation is very easily distinguished from 

 that of the restiform body, the complete separation of the two 

 being very beautifully shown in horizontal sections through the 

 base of the cerebellum. The restiform body appears as a dense 

 compact mass, lying lateral to the ascending nucleo-cerebellar 

 tract, and passing upward at an inclination which brings its point 

 of decussation well anterior to that of the vestibular group. The 

 discrete smaller bundles and ribbon-like strands constituting the 

 latter are totally different in appearance from the compact solidity 

 of the former. 



The distribution of fibers of the ascending path to the superior 

 nucleus follows the same general arrangement of ribbon-like 

 strands, curving around towards the medial side in the anterior 

 end of the superior nucleus, in a manner which serves to some 

 extent as an index to the boundary of the nucleus in this direction. 



The outlines of the superior vestibular nucleus as previously 

 noted, are not very definite. The mass lies in the lateral wall 

 of the ventricle and forms in a general way a blunt prolongation 

 of the long axis of the descending root. It is much cut up by 

 strands of fibers ascending towards the cerebellum or terminating 

 in its substance. Its close relation to the nucleus of the fifth 

 nerve, especially the sensory division, which lies immediately 



