792 



THE NERVOUS SYSTEM 



from the base of one of the dendrites, and pass outwards into the molecular layer, where they 

 bifurcate and course in both directions parallel to the long axis of the folium, to become associated 

 with the dendrites of the cells of Purkinje. In the layer of the cells of Purkinje there is situated 

 at intervals a neurone of the Golgi type 1 1 (see lig. r>.V>). The short, elaborately branched axone 

 of this neurone is distributed among the cells of the granular layer. Axones conveying impulses 

 to the cerebellar cortex terminate in the granular layer as 'moss fibre*,' or directly upon the 

 cells of Purkinje as 'climbing fibres,' and probably upon the cells of the Golgi type II. 



Thus the neurones which receive impulses coming to the cortex are the cells of Purkinje, 

 probably the Golgi cells of type II, and the granule-cells; those which distribute these impulses 

 to other neurones of the folium are the Golgi cells of type II, the granule-cells, and the basket-cells 

 (association neurones), and the collaterals of the cells of Purkinje. Impulses are conveyed from 

 the cortex of a folium to that of other folia, lamina, lobules or lobes, or to the nuclei of the cere- 

 bellum, or to structures outside the cerebellum by the axones of the cells of Purkinje. 



The nuclei of the cerebellum are in its central core of white substance. They 

 are four in number, and all are paired, those of each pair being situated opposite each 

 other on either side of the mid-line. 



1. The largest of them is the dentate nucleus. This is an isolated mass of grey 

 substance situated in the core of white substance of each hemisphere. It is in the 

 form of a folded or corrugated cup-shaped lamina, with the opening of the cup 



FIG. 588. SECTION OF CEREBELLUM AND BRAIN-STEM PASSING OBLIQUELY THROUGH INFERIOR 

 PORTION OF CEREBELLUM TO ANTERIOR MARGIN OF PONS. (After Toldt, "Atlas of Human 

 Anatomy," Rebman, London and New York.) 



POSTERIOR CEREBELLAR NOTCH 



VERMIS (superior) 



MEDULLARY LAMINA 

 CORTICAL SUBSTANCE 



CORPUS MEDUL- 

 LARE 



CAPSULE OF 

 DENTA TE NU- 

 CLEUS 

 DENTATE NUCLEUS 



CORE OF THE DENT A TE 



NUCLEUS 



HILUS OF DENTATE NU- 

 CLEUS 

 URACHIUM CONJUNCTIVUM 



FOURTH VENTRICLE 



FOSSA RHOMBOIDEA ( purs ivprriar) 



STRATUM KUCLEARE 



DECUSSATION OF BRACHIUM CON- 

 JUNCTIVUM 



NUCLSV3 

 OLOBOSUS 



NUCLEUS 



PONS ( VAROLII) 



NUCLEUS EMBOLI- 

 fOBJOS 



LINGULA CEREBELLI 



.1 NTEK1OR MED I 'LLARY 



VELUM 



St'BKTANTIA FEKKUdlXEA 

 LATERAL LEMN1SCUS 



MEDIAL LOXiilTI'DINAL 



FASCH'I'l.l x 

 RAPHE OF MEDULLA OBLONG ATA 



CEREBRAL PEDUNCLE 

 ISTERPEDUNCULAR FOSSA 



(hilus) directed anteriorly and obliquely inwards. It contains a mass of white 

 substance and possesses a capsule. 



2. The nucleus emboliformis is an oblong and much smaller mass of grey 

 substance, which lies immediately internal to the hilus of the dentate nucleus. It 

 is probably of the same significance as the dentate nucleus, being merely a portion 

 separated from it. 



3. The nucleus globosus, the smallest of the cerebellar nuclei, is an irregular 

 horizontal mass of grey substance with its larger end placed in front. It lies close 

 to the inner side of the nucleus emboliformis, and often appears separated into two 

 or more rounded or globular masses. 



4. The nucleus f astigii (roof nucleus) is the second largest of the cerebellar nuclei, 

 and is the most mesially placed. The pair is situated in the roof of the fourth ven- 

 tricle, and so near the mid-line that both nuclei are in the white substance of the 

 vermis. They are ovoid in shape, and the nucleus of one side receives axones from 

 the nucleus of the vestibular division of the eighth cranial nerve chiefly of the oppo- 

 site side, the decussation of these axones taking place in the vermis. Its cells are 

 larger than those of the two first-mentioned nuclei. 



The peduncles of the cerebellum. The peduncles consist of three pairs the 



