THE BRAIN. 



491 



The Cerebellum. The cerebellum (Figs. 280, 281) is com- 

 posed externally of gray matter, which also penetrates into the 

 substance of the organ, forming with the white matter the lamince. 

 In the central part of the cerebellum is white matter, in which is 

 imbedded a collection of gray matter, the corpus dentatum. The 

 cerebellum is connected with the rest of the encephalon by the 

 superior, the middle, and the inferior peduncles. The superior 

 peduncles ( processus e cerebello ad tester) connect the cerebellum 

 with the cerebrum ; the middle peduncles (crura cerebelli) con- 

 nect the two cerebellar hemispheres; the inferior (processus ad 

 medullam) connect the cerebellum and medulla oblongata. 



The gray matter consists of two layers, an inner or granular 

 layer, composed of nerve-cells, principally small in size, and 

 neuroglia ; and an outw or molecular layer, composed of fine nerve- 

 fibers and nerve-cells. Between these two layers are the cells 

 of Purkinje, which are flask-shaped, and from the base of each of 

 which is given off a neuron, which is continued as an axis-cylinder 



Dendrite. 



Cell-body. 



Neuraxis. 



FIG. 282. Cell of Purkinje from the human 

 cerebellar cortex ; chrome- silver method ; X 120 

 (Bohrn and Davidoff). 



Neuraxis. 



Claw-like telo- 

 dendron of 

 dendrite. 



FIG. 283. Granular cell 

 from the granular layer of 

 the human cerebellar cortex ; 

 chrome-silver method; X 100 

 (Bohm and Davidoff). 



of a medullated nerve-fiber of the white center. From the opposite 

 side are given off dendrons which pass into the gray matter. In 

 discussing the structure of the cerebellum, Schafer says : " The 

 dendrons of the cells of Purkinje spread out in planes trans- 

 verse to the lamellae of the organ, so that they present a different 

 appearance according to whether the section is taken across the 



