692 



THE NERVOUS SYSTEM. 



a sort of limiting membrane beneath the pia mater, analogous to the membrana 

 limitans interna in the retina, formed by the fibres of Miiller. 



The cells of the molecular layer are small, and are arranged in two strata, an 

 outer and an inner. They all possess branching axis-cylinder processes ; those of 

 the inner layer run for some distance horizontally, i. e., parallel with the surface of 

 the folia, giving off at intervals collaterals, which pass in a vertical direction 

 toward the cell-bodies of Purkinje's corpuscles, around which they become enlarged, 

 and ramify like a basket. Hence these cells of the inner layer are named basket- 

 cells. 



The corpuscles of Purkinje (Fig. 368) are flask-shaped cells, situated at the 

 junction of the molecular and granular layers, their bases resting against the latter. 



External gray or 

 cellular layer. 



Corpuscles of Purkinje. 



Internal or rust- 

 colored layer. 



-_ White substance. 



FIG. 368. Vertical section through the gray matter of the human cerebellum. Magnified about 100 diam- 

 eters. (Klein and Noble Smith.) 



From the bottom of the flask the axis-cylinder process arises ; this passes through 

 the granular layer, and, becoming medullated, is continued as a nerve-fibre in the 

 medullary substance beneath. This axon gives off fine collaterals as it passes 

 through the granular layer, some of which run back into the molecular layer. 

 From the neck of the flask numerous dendrites are given off, which branch in an 

 antler-like manner in the molecular layer and terminate in free extremities. 



The internal rust-colored or granular layer (Fig. 368) is characterized by con- 

 taining numerous small nerve-cells or granules of a reddish-brown color, together 

 with many nerve-fibrils. Most of the cells are nearly spherical and provided with 



