96 C. WINKLER. THE CENTRAL COURSE 



nucleus of DEITEKS. They go at first ending tho the lateral and 

 principal cells of the dorsal nucleus, and to the nucleus of the VI th 

 nerve (Plate XIV fig. 14 A). Those nuclei are thickly specked with 

 black granules after rootsection. Secondly an important number of 

 these fibres are ending in the nucleus griseus. Round the nucleus of 

 BECHTEIIEW and in the whole long nucleus griseus of the descendent 

 root , ascending and descending rootfibres enter. They pass through the 

 nucleus of DEITERS but they do not end among the large cells of it. 



This nucleus is passed by all the rootfibres of the dorsal radia- 

 tion, but yet there is found not a single symptom that rootfibres 

 should be dissolved in collaterals or make any other contact with the 

 cells, which certainly are not in direct contact with the root-fibres. 

 Neither for the large cells of the tuberculum acusticum nor for the 

 larger cells in the dorsal-proximal pole of the ventral nucleus a 

 direct contact with rootfibres could be demonstrated, and in this regard 

 the cells of DEITERS have not such a peculiar position among the 

 secundary systems of the nervus octavus as often has been presumed. 

 This however is a question, which afterwards will be discussed. 



Until now the portio interim of the corpus restiforme contains 

 at least three regions. 



l e . a dorso-lateral quadrant the nucleus of DEITERS. 



2 e . a ventro-medial quadrant the descending root with its nucleus 

 griseus. 



3 e . The medio-dorsal border of transverse dorsal root-fibres. They 

 form part of the dorsal rootfibres passing the portio interim in 

 every direction. 



There still remain the non -degenerating fibres in the dorsal 

 radiation. 



That a secundary system passed into the intermedial system and 

 into the descendent root I have already made probable. There 

 also passes one in the dorsal transverse fibres. 



But Marchi-method after rootsection leaves two large quadrants 

 of the portio interna without degenerated fibres in the longitudinal 

 axis of the medulla (Plate IV fig. 4). 



The dorso-medial quadrant, where a great many secundary audi- 

 tory fibres will soon be recognised , mixed with fibres originating 

 from the cerebellum, and a ventro-lateral triangular area where again 

 (between oval area and spinal root of the V) non degenerated fibres 

 may be found. 



The relations of the root-fibres to the dorsal nucleus n. octavi 

 and the portio interna being such as described here , the farther 

 course of the dorsal system may be studied. 



