92 C. W1NKLER. THE CENTRAL COURSE. 



o. The portio internet corporis restiformis (juocta-restiform body] 

 and the root-Jibres of the ventral root, 



As the portio interna, lying between the oval area of the C. R. 

 and the dorsal auditory nucleus, is nearly everywhere passed by 

 or composed with auditory root-fibres, it is necessary to give a 

 minute description of its relations to these fibres. 



In frontal sections, its distal end begins as soon as the nuclei of the 

 posterior spinal columns reach their proximal endings. As soon as 

 the dorsal ascending spino-cerebellar tract (FLECHSIG'S Kleinhirn- 

 Seitenstrangbundel), covering dorsally the spinal V th root, attains 

 its place in the oval area , grey matter appears at the medio-dorsal 

 side of this tract. (Plate VIII fig. 1 5 N. 1 and N. 2). There it 

 is situated laterally of the proximal ending of the nucleus of BURDACH, 

 and as here the fibre-mass of the posterior spinal column soon has 

 found an end, there appears rather abruptly an area of transverse 

 sectioned nerve-fibres, united in little separate bundles, medio- 

 ventraliy from this grey matter, (see fig. 15 N. 3 on Plate VII). 



The grey matter is the nucleus proprius of the restiform body, 

 the area with separated bundles contains the distal bundles of the 

 radix clescendens nervi octavi. (Plate VII fig. 15 IN . 3 in N. C. R. 

 and in r. desc. N. VIII;. Together they form the distal end of the 

 portio interna. 



As soon as the nuclei from the posterior columns have ended, 

 at first laterally but soon dorsally of the nucleus of the X th nerve 

 (Plate VIII fig. 15 N. 4. n. d. N. VIII) the dorsal nucleus also 

 makes its appearance, arid from that moment the different constituants 

 of the juxta-restiform body are present. Bordered at its medial side 

 by the dorsal nucleus and closely related to it, ventrally resting 

 upon the V th spinal root, laterally limited by the rapidly growing 

 oval area, it extends proximally unto the entrance of the superior 

 cerebellar peduncle. 



Somewhat distally from the appearance of the tuberculum acus- 

 ticum the nucleus of DEITERS is at first seen. The first large cells 

 of this nucleus are always found in the dorso-lateral edge of the 

 portio interna (Plate VII fig. 7 A H) but as long as the tuber- 

 culum covers the oval area, those cells are not found dorsally from 

 this area. As soon as the stratum latero-dorsale and the tuberculum 

 are diverging from the area ovalis, DEITERS' nucleus is dorsally 

 resting upon it and exfoliating laterally from it, it is crossed by 

 root- and secundary fibres curving in the systema dorsale nervi 

 octavi round the oval area. 



