204 



THE NERVOUS SYSTEM 



Close to the median plane in the medullary body of the vermis, where this forms 

 the tent-like covering of the fourth ventricle, is the nucleus of the roof or nucleus 

 fastigii. 



The dentate nucleus is well developed only in those animals which possess 

 large cerebellar hemispheres. It receives fibers from the cortex of the cere- 

 bellar hemisphere, while the nuclei fastigii and globosi receive fibers chiefly 

 from the vermis (Clark and Horsley, 1905; Edinger, 1911). It is probable that 



Decussation of brachia conjunctiva --, : 

 Medial longitudinal fasciculus--^' 



\"' 

 Brachium 



Molecular layer 

 Granular layer 



Rhomboid fossa 

 ' 



^y A nterior medullary velum 

 Lingula of cerebellum 

 Fastigial nucleus 



Hilus of dentate nucleus 

 Dentate nucleus 



Medullary lamina' 4 

 Cerebellar folia-'-' 



Medullary substance of /' 

 hemisphere 

 Emboliform nucleus 



Globose nucleus 



Vermis 



Capsule of dentate nucleus 

 Posterior cerebellar notch 



Fig. 148. Horizontal section through the cerebellum showing the location of the central nuclei. 



(Sobotta-McMurrich.) 



a functional localization similar to that in the cerebellar cortex will be found 

 to exist in the central nuclei. In histologic structure the central nuclei closely 

 resemble the inferior olive. 



THE CEREBELLAR PEDUNCLES 



The white core of the cerebellum is formed in large part of fibers which enter 

 and leave the cerebellum through its three peduncles. 



The brachium pontis, or middle cerebellar peduncle, is formed by the trans- 

 verse fibers of the pons and carries impulses which come from the cerebral cortex 

 of the opposite side. It enters the cerebellum on the lateral side of the other 

 two, and is distributed in two great bundles: one from the rostral part of the 

 pons radiates to the caudal part of the cerebellar hemisphere; the other, from the 

 caudal part of the pons, spreads out to the rostral portion of the hemisphere. 

 In man, as might be expected from the large size of the pons and cerebellar 



