Johnston, The Radix Mcsencephalica Trigemini. 633 



for as Fig 28 clearly shows, the mesencephalic root is running 

 directly through the sensory nucleus. There now appears in this 

 section the most dorsal portion of the main sensory root of the 

 trigeminus, just at the point where it is giving fibers to the sensory 

 nucleus and where the most of its fibers are turning caudad as the 

 spinal trigeminal tract. There also appear in the figure the root of 

 the vestibularis and of the motor facialis. 



In Fig. 29 appear besides the sensory and motor roots and nuclei 

 of the trigeminus, the motor facialis, the cochlearis, fibers of the 



- ' 'Vmot.nuc. ", 



Fig. 28. The fourth section of this series ventral to the last, x 20. Descrip- 

 tion in text. 



trapezoid body, etc. The motor bundles of the trigeminus are col- 

 lected opposite the cephalic end of the motor nucleus, except the 

 bundle z, which still receives decussating fibers and is closely related 

 to bundle a of the mesencephalic root. The fibers of the h-c area 

 have now collected into two fairly distinct groups of small bundles. 

 The bundles c are evidently joining the sensory root and are inter- 

 mingled with the fibers which are passing caudad in the spinal tri- 

 geminal tract. The other relations in this figiire will be clear from 

 the labelling. 



