THE PONS VAROLII 



497 



nucleus, being penetrated by the cochlear nerve, is thus divided 

 into two portions, a ventral or accessory nucleus, and a dorsal 

 nucleus or tuber culum acusticum. Between the cochlear nuclei 



FIG. 386. A SECTION THROUGH THE MIDDLE OF THE HUMAN PONS VAROLII. 



BPo, middle cerebellar peduncle ; cH, central tract of the tegmentum ; Crst, restiform 

 body ; Fc V, the accompanying tracts of the trigeminus ; Flp, posterior longitudinal 

 bundle ; fist, peduncle of the flocculus ; fpPo, longitudinal pontine fibres ; fprd, predor- 

 sal bundle ; Lm, mesial lemniscus ; m, dorsal longitudinal bundle of Schutz ; NaB, nu- 

 cleus of von Bechterew ; Nft, nucleus of the eminentia teres ; Nrtg, reticular nucleus of 

 the tegmentum; NTr, trapezoid nucleus; NVI, abducens nucleus; NVIac, accessory 

 nucleus of the abducens; NVII, facial nucleus; Nvm, motor nucleus of the trigeminus; 

 Nvt, triangular or chief nucleus of the vestibular nerve ; Py, pyramid ; Sgl, gelatinous 

 substance of Rolando ; so, peduncle of the superior olive ; Strap, striae acusticae ; Strc, 

 middle, Strp, deep, and Sirs, superficial layer of the pons ; Ten, nucleo-cerebellar tract ; 

 TV,. trapezoid body; Trs, rubro-spinal tract of von Monakow ; Tscv, Gowers' tract ; Tst\ 

 spino-tectal and thalamic tract; F, trigeminus ; t>a, bundle of Vicq d'Azyr ; F/, abdu- 

 cens ; Vllb, second ; and VHc, third portion of the facial root ; Villa, spinal vestibular 

 root. Weigert's stain, x 3J. (After Marburg.) 



and the ventro-lateral wall of the fourth ventricle the grey matter 

 of the formatio reticularis appears to be directly continued later- 

 alward into the substance of the cerebellum. 



Just at this point is a disseminated group of very large nerve 

 33 



