64 



are fania-nea tally liffersnt from the solii Laminae familiar to 

 us ia higher vertebrates. 



The arrangement of the strictupal elements of the cere- 

 bellum is readily folLo^ei, for in no other part of the brain 

 are iistinctions more clearly marked. Superficially, there is 

 the molecular layer ( Big. 18, m. 1 . ); the granular layer lies 

 next to the ventricle, or is separated from it only by the 

 basal fibres (Pig. 12, g.l. ) ; between the t/fo, there is the layer 

 of Purkinje (ftig.l?,p.l. ). 



The nerve-fibres of the organ are found in two well-defin- 

 ed groups, the basal fibres and the median fibres. The basal 

 fibres (Fig. 18,b. f . ) enter the posterior region from the ob- 

 longata and soon become dissolved in the outer layers. These 

 fibres lie next to the ventricle, and they supplant the gran- 

 ular layer entirely during their course, or at least displace 

 it quite largely. The median fibres are disposed in scattered 

 bundles which lie in the outer part of the granular layer just 

 beneath the cells of Purkinje. The bundles take two general 

 directions: transverse, (cut across in Plg.l2,m. fC ); and longi- 

 tudinal, extending parallel witn the str.ictural zones (Pig. 18, 

 m.f.). 



1. The Neurones of Purkinje. 

 The neurones of Purkinje are the largest, and by far the 

 most impressive strictiral elements of the cerebellum. Their 



