OF THE NEKVUS OCTAVUS. 125 



The IV th and the distal end of the III th nucleus and that of 

 the VI th nerve; in a lesser degree the facial nucleus, the motor 

 nuclei N. X, and the nuclei funiculi lateralis; least that of the 

 XII th . Uninterested surrounded at all sides by a large quantity of 

 degenerate fibres the motor quintus nucleus is lying. 



2 ly from the descending root and also from the descending tract 

 of DEITERS , there however originate dorsal transverse fibres , not 

 ending in the described nuclei but passing the raphe. 



They go ventrally and dorsally from the genii of the nervus VII , 

 they even penetrate through it, pass the raphe, provide the contra- 

 lateral nucleus of the VI th nerve withe a large quantity of fibres , 

 pursue their course in the contra-lateral layer of transverse fibres 

 and reaching there the portio interna , they accompany the descen- 

 ding rootfibres giving there again collaterals to the contra-lateral 

 nucleus nervi VI (Plate XVI fig. 20 D). 



In this way, the descending root of the opposite side receives a 

 secundary system through the transverse dorsal fibres and in the 

 same way as the secundary system in the contra-lateral descending 

 DEITERS tract, it is less important than that of the same side. 



3 ly a great many degenerate fibres of the dorsal transverse layer 

 however , at their reaching the raphe bend in a longitudinal direction, 

 forming in the fasciculus longitudinalis posterior an ascending and 

 a descending tract. 



After one-sided section of the systema dorsale it appears that the 

 contra-lateral f. 1. p. is degenerated more intensely. The same fact 

 I have stated after rootsection on one side. 



The proximal part of this tract , giving fibres to the contra-lateral 

 nucleus N. VI diminishes rapidly. The contra-lateral VI th nucleus, 

 as has been shown, now being provided from three sides, from 

 dorsal transverse fibres after their crossing the raphe , from the contra- 

 lateral fasciculus longitudinalis posterior and from the descending 

 root , is degenerated to such an intense degree , that its degeneration 

 hardly differs from that at the same side. The fasciculus longitu- 

 dinalis posterior however do not leave all its degenerate fibres in 

 this nucleus and in sections proximally from the levels of the VI th 

 nucleus there are still found a few degenerate fibres in it. They 

 may be followed to the IV th nucleus causing there a very slight 

 degeneration (Plate XVI fig. 20 B). It is not quite clear however, 

 where the larger part of those degenerate fibres remains. 



Now, as it may be seen in fig. 20 G, the bracchium conjunc- 

 tivum ped. cereb. sup. is divided. The subsequent degeneration is 

 seen (fig. 20 D) in this bracchium towards the contra-lateral red 



