604 NEHVOUS SYSTEM. 



The gray matter in the floor of the ventricle consists of a tolerably thick 

 stratum, continuous below with the gray commissure of the cord, and extending 

 up as high as the aquasduct of Sylvius, besides some special deposits connected 

 with the roots of origin of certain nerves. In the upper half of the ventricle 

 is a projection situated over the nucleus, from which the sixth and facial nerves 

 take a common origin. In the lower half are three eminences on each side for 

 the roots of origin of the eighth and ninth nerves. 



For further information on the Descriptive Anatomy of the Nervous Centres, consult : Crn- 

 veilhier's " Anatomic Descriptive ;" Todd's " Descriptive Anatomy of the Brain, Spinal Cord, 

 and Ganglions;" Herbert Mayo's " Plates of the Brain and Spinal Cord ;" and Arnold's " Tabulae 

 Anatomicae, Fascic. 1. Icoiies Cerebri et Medullas Spinalis." 



