70 C. WINKLER. THE CENTRAL COURSE 



series of horizontal sections. In fior. 16 A the thick degenerated 



O O 



tibres for the opposite nucleus trapezoides are found (the stratum a}. 



Somewhat more dorsally (in tig. 16 B) the degenerated smaller 

 tibres for the ventral tegmenturn-nuclei (the stratum b). In the 

 figures 16 C and 1) the most dorsally situated degenerated root- 

 fibres (the stratum d) appear. Expecially fig. 16 1) is very demon- 

 strative. From the dorsal border of the olivary body opposite to 

 the rootsection part small degenerated fibres. They cross theraphe, 

 go towards the dorsal part of the medullary capsule of the same 

 sided oliva and reach from there the degenerated homolateral corpus 

 trapezoides. These are the rootfibres in the stratum d from the 

 systema ventrale nervi octavi. 



But not all the transverse fibres here described take that way. 

 A certain number of them do not enter into the corpus trapezoides, 

 but are united at the dorsal top of the same sided olivary body 

 into a separate bundle (Plate IX fig. 16 F in //). This bundle of 

 now queer-sectioned degenerated nerves enters in the formatio gela- 

 tinosa of the V th nerve (Plate X fig. 16 F in /). It passes the 

 spinal root in a ventro-dorsal, and at the same time medio-lateral 

 direction (Plate X fig. 16 G, H and I in //) until the portio interim 

 of the restiform body is reached. 



There, lying laterally from the radix descendens N. V11I , it is 

 found at the medial border of the oval area, confining it against 

 the portio interna and turning dorsally it disappears between the 

 degenerated fibres of the stratum latero-dorsale at the dorsal border 

 of the oval area of the restiform body (Plate XI fig. 16, K and L). 

 The study of the horizontal sections shows, that, after the auditory 

 root-section , the most dorsal layer of rooffibres - - the stratum d - 

 may not only be pursued in the corpus trapezoides (into the ven- 

 tral system) but also into the stratum latero-dorsale of the corpus 

 restiforme by means of an intermediary bundle of rootfibres. 



This bundle, first discovered by HELD, may be called the 

 systerna intermedium nervi octavi, for it unites fibres of the dorsal 

 with fibres of the ventral system. This system contains partly root- 

 fibres of both roots, partly fibres of a secundary system. 



This intermedial system may be very well demonstrated in frontal 

 sections of the normal animal, for instance in fig. 13$ on Plate 

 III , it is very well developed. 



After removal of the cochlea, some fibres in this system are 

 brought to degeneration and frontal sections are better adopted 

 to demonstrate the course of the intermedial fibres in the latero- 

 dorsal stratum of the restiform body. 



