SO C. WINKLER. THE CENTRAL COURSE 



now are ranged in the lateral layer of the stratum latero-dorsale. 

 There between the latero-dorso-proximal portion of the ventral 

 nucleus (always providing this with fibres) and the oval area they 

 run dorsally from this area, but soon diverging from it , they form 

 the external radiation of the fan , radiating dorsally round the 

 oval area. 



These fibres of the external layer of the stratum latero-dorsale , 

 bear as its stratum medullare profundum the tuberculum acusticum. 

 They are degenerated in an intensive manner after removal of the 

 cochlea (fig. la on Plate I) perhaps still more intensive after nerve 

 section (Plate IV fig. 4) and in the distal regions of the stratum- 

 latero dorsale , they a forming a second system of root-fibres. 



Therefore now already two systems appear, participating to the 

 systema dorsale nervi octavi dorsally from the oval area, and both 

 being root-fibres. 



Between the intqrmedial system curving closely round the oval 

 area, and the rootfibres, which in distal regions form the stratum 

 profundum medullare tuberculi acustici however new fibres make 

 their appearance. 



They are fibres , which do not degenerate , even after the section 

 of the nerve (fig. \a on Plate I in /3). 



They are found already in distal sections and increase in quantity 

 proximally. 



They are secundary fibres emanating from the dorsal and proximal 

 border of the ventral nucleus and from the tnberculum acusticum. 



They are mixed among the degenerated fibres of the two des- 

 cribed layers but in the middle part of the radiation of the fan , 

 they form a layer of intact fibres where nearly no degenerated 

 fibres are found. But here no longer may be spoken of the stratum 

 latero-dorsale, another portion of the systema dorsale nervi octavi 

 has begun , usually called MONAKOW'S stria medullaris acustica. As 

 to its distal end , it is now composed of : 



J e degenerated root-fibres of both roots, partly forming the 

 intermedia! system , the internal layer ; 



2 e intact fibres of a secundary system ; 



3 e degenerated root-fibres, chiefly belonging to the dorsal root, 

 the external layer. 



The latter fibres form the basis, on which the tuberculum acus- 

 ticum is resting, and may be also called the stratum profundum 

 medullare of this ganglion. They are sectioned longitudinal!) in 

 frontal sections. 



Perpendicular to the course of these fibres very small degenerated 



