THE CENTRAL NERVOUS SYSTEM 683 



in the dentate nucleus of the cerebellum, partly in the vermis, 

 and among the fibres which end in the vermis are those "of 

 direct cerebellar tract. 



Connections of the Antero-lateral Ascending Tract. According 

 to Schafer, the axons of this tract are also connected with cells situ- 



u.m.f. fn 



FIG. 246. TRANSVERSE SECTION or 

 MEDULLA OBLONGATA AT THE LEVEL 

 OF THE DECUSSATION OF THE FILLET 

 (HALLIBURTON, AFTER SCHWALBE). 



a. m.f., anterior, and/. m.f., posterior median 

 fissure ; /. a and /. a 2 , external arcuate fibres ; 

 /. a', internal arcuate fibres becoming external ; 

 . a. r, nuclei of .arcuate fibres ; py, pyramid ; 

 o, o, lower end of nucleus of olive ; f. r, for- 

 matio reticularis ; . /, lateral nucleus ; . g, 

 nucleus gracilis ; f. g, funiculus gracilis ; n. c, 

 nucleus cuneatus ; nc', external cuneate nucleus ; 

 /". c, funiculus cuneatus ; g, substance of 

 Rolando ; c. c, central canal surrounded by 

 grey matter ; . XI, nucleus of spinal accessory ; 

 n. XII, of hypoglossal ; a. V, ascending root 

 of fifth nerve ; j. 5., the decussation of the fillet, 

 or superior decussation. 



p. nor. 



FIG. 247. TRANSVERSE SECTION OF 

 MEDULLA OBLONGATA AT ABOUT THE 

 MIDDLE OF THE OLIVE (HALLIBURTON, 

 AFTER SCHWALBE). 



/. /. a, anterior median fissure ; n. a. r, arcu- 

 ate nucleus ; p, pyramid .; n. XII, hypoglossal 

 nucleus ; XII, root bundle of hypoglopsal nerve 

 coming off from the surface ; at b it runs between 

 the pyramid and the dentate nucleus of the olive, 

 o; f. a. e, external arcuate fibres ; . /, lateral 

 nucleus ; a, arcuate fibres going to restiform 

 body c. r, partly through the substantia gela- 

 tinosa g, partly superficial to the ascending root 

 of the filth nerve a. V ; X, root-bundle of vagus ; 

 n. X, n, X' , two portions of vagus nucleus; 

 /. r, foimatio reticularis ; n.g, nucleus gracilis ; 

 n. c, nucleus cuneatus ; n. t, nucleus of the 

 funiculus teres ; n. am, nucleus ambiguus ; 

 r, raphe ; o', o", accessory olivary nucleus ; 

 /. o. /, peduncle of the olive. 



ated in Clarke's column. For when both the antero-lateral ascending 

 and the direct cerebellar tracts are divided a much larger number of 

 the cells of the vesicular column are involved in the resulting chro- 

 matolysis and atrophy than when the lesion is confined to the direct 

 cerebellar tract alone. But some of the fibres of the tract may have 

 a different source (from cells at the base of the anterior horn on the 



