CEREBELLUM, PONS, AND MEDULLA, 



231 



nate in arborizations or baskets that doubtless make connections 

 with the dendrites of the Purkinje cells. 



i.C B ■ '■'■■'A-' 



Fig. 103. — Histology of the cerebellum. — (From Obersieiner.) 



A consideration of this peculiar and intricate structure enables 

 us to comprehend that the cerebellar cortex presents a reflex arc 

 of a very considerable degree of complexity. The incoming im- 

 pulses through the moss and climbing fibers may pass at once to the 

 Purkinje cells and lead to efferent discharges, or they may end in 

 the cells of the granular or molecular layer and thus be distributed 

 to the Purkinje cells in a more indirect way. In addition to the 

 cortex the cerebellum contains several masses of gray matter in 

 its interior: the large dentate nucleus in the center of each hemi- 

 sphere and the group of nuclei l3'ing in or near the middle of the 

 medullary substance of the vermiform lobe (nucleus fastigii, n. 

 globosi, and the n. embolif ormis) . The axons of the Purkinje 

 cells of the cortex terminate in these subcortical nuclei, and the 

 efferent path from the cerebellum is then continued by new 

 neurons. Thus, the fibers of the superior peduncles (brachium 

 conjunctivum) of the cerebellum arise chiefly from the dentate 

 nuclei, and only indirectly from the cortex. The anatomical 

 connections, afferent and efferent, between the cerebellum and 

 other parts of the nervous system are very complex and not 



