OF THE NERVUS OCTAVUS. 147 



2 ly ascending fibres. Of these the greater part remain in the here 

 described area, among the cells found there. Other fibres provide 

 the proximal portion of the angular nucleus, and of the nuclei in 

 pedunculus cerebelli (fig. 26 1) E). 



3 ly transverse fibres. Most of these participate to the formation 

 of the surroundings of the nucleus parvo-cellularis N. octavi. But 

 a great many of these fibres are going rnedialward. 



To these latter other transverse fibres join, running in the same 

 direction, but issued from the descendent and ascendent roots. All 

 these fibres participate to the formation of the dorsal systema N. 

 octavi, wich will be treated afterwards, (fig. 26 A E). 



The large area here described indeed is an area, into which 

 most of the rootfibres enter. Together with the ventral bundle and 

 with the systema dorsale N. octavi, it offers by far the most 

 extensive, and perhaps also the most interesting part of the portio 

 interim of the pedunculus cerebelli inferior. 



4 ly . In the dorsal border of the portio interim, however, is found 

 the nucleus magno-cellularis already mentioned before. 



This nucleus containing very large cells, and embraced by the 

 transverse and ascending fibres of the ventral root - - all degenerated 

 after the removal of the labyrinth - - is found without any dege- 

 neration if the labyrinth is removed. 



The embracing rootfibres do not end in it. Perchance a single 

 degenerate fibre may pass through it, but as a clear spot between 

 the black degenerated nucleus angularis and nucleus parvo-cellula- 

 ris, it is very distinctly marked in proximal sections. Distally the 

 nucleus may be traced, in the dorso-lateral edge of the portio 

 interim (fig. 26 B, C, D and E.), not so far as to the entrance 

 of the distal root. Going from this entrance in proximal direction, 

 at first the nucleus angularis, soon afterwards the nucleus parvo- 

 cellularis and at last the nucleus magno-cellularis, appears, and it 

 always retains its place between these two nuclei (fig. 26 B E). 



After all, a portio interna of the restiform body may be recog- 

 nised in pigeons as well as in rabbits , and in this area are found 

 different divisions differently behaving towards the octavus-rootfibres, 

 and composed by root-fibres as well as by fibres of other origin. 



b. The rootfibres in the systema dorsale nervi octavi. 



It has been demonstrated, that the ventral bundle was divided 

 in descending, ascending and transverse dorsal fibres. All those 



fibres , but chiefly the latter ones have contributed to the formation 



10* 



