708 



THE CEREBELLUM 



cells of the granular layer. The long ascending ones are known as tendril fibers 

 and the short ones as moss fibers, so-called on account of the peculiar thickenings 

 which they exhibit close to their points of termination. Ramon y Cajal believes 

 that the tendrils are the terminals of the fibers of the middle peduncle, while the 

 moss fibers are derived from the afferent fibers of the inferior peduncle. The 

 efferent fibers are formed by the axons of the cells of Purkinje. They end in the 

 deep nuclei, whence their impulses are conveyed onward by secondary neurons. 





Fig. 353. — Section of Cortex of Fig. 354, — A Purkinje Cell of the 

 Cerebellum. Cerebellar Cortex. Golgi Method. 



a, Pia mater; h, exterior layer; c, a, Axon; b, collateral; c, d, ramifications 

 layer of cells of Purkinje; d, inner 

 or granular layer; e, medullary center. 

 (Sankey.) 



of dendrons. (Cajal.) 



The cerebellum also contains certain collections of gray matter beneath its 

 cortex. Within the vermis and above the fourth ventricle are found the so-called 

 roof ganglia, consisting of the nuclei fastigii situated near the middle line, the 

 nuclei emboliformes located in a dorsal direction from the former, and the nuclei 

 globosi. Directly embedded in the white matter of the hemispheres are the deep 

 nuclei of which the nuclei dentati are the most conspicuous. As has been stated 

 above, the latter form stations upon the efferent paths, and the former stations upon 

 the afferent paths. Each incoming fiber divides into many branches and is thus 

 brought into relation with the greatest possible number of cells of the granular layer. 



