120 C. WINKLER. THE CENTRAL COURSE 



nucleus. It may be presumed , that the degenerated pedunculus 

 cerebelli superior , after passing the raphe sends fibres into the fasc. 

 longitudinalis posterior and in the fasc. praedorsalis backwards. My 

 experience in regard to this is conform to that of VAN GEHUCHTEN. 

 But this presumption does not enable us to interprete the prevailing 

 of degenerate fibres in the contra-lateral fasc. long. post, in sec- 

 tions falling proximally from the nucleus of the VI th nerve after root- 

 section. Even if (in the case drawn in fig. 20) fibres from the dege- 

 nerated bracchium conjunctivuin pedunculi cerebelli superior might 

 have increased here the contra-lateral degeneration in the fasciculus 

 longitudinalis posterior, it still would be too intense, to be caused 

 by those fibres which only may exist in small number. 



Therefore I believe that there exist fibres, issued from the nucleus 

 ventralis nervi octavi and from the nucleus DEITEKS of the opposite 

 side, which take temporary a place in the contra-lateral fasc. long, 

 post, to provide chiefly the nucleus VI of that side, in a far lesser 

 quantity the nucleus IV and X, but leaving it also to reach the 

 medial bundle of the lateral fillet. 



All contra-lateral degenerated fibres in the fasc. long. post, remain 

 within the medulla oblongata. 



At the proximal top of the XII th nerve, the degeneration prevails 

 in the fasc. long. post, of the operated side, but these fibres have 

 quite an other signification. Many transverse dorsal fibres namely 

 have remained at the same side in the fasciculus longitudinalis 

 posterior and bending distally they have a slight ventral inclination, 

 in such a way that in proximal sextions being longitudinal fibres 

 of the fasc. long. post, they gradually pass distally into the fasc. 

 praedorsalis. Now from the degenerate transverse fibres in the 

 decussatio of MONAKOW and from that of HEI/D , there also bend 

 fibres in the homo-lateral fasc. praedorsalis and take a longitudinal 

 course. 



At the level of the .XII th nucleus (Plate XVIII fig. 22 F and G, 

 Plate XX fig. 25 L, Plate VIII fig. 15 N. 5 N<\ 1) the fasci- 

 culus longitudinalis posterior and the fasc. praedorsalis are no longer 

 differentiated. There now is in the medial field of the medulla 

 oblongata, between the stratum interolivare (LEVANDOWSKI'S lemniscus 

 principalis) and the dorsal nuclei an intense degeneration at the 

 same side and a much less intense, but still evident one, at the 

 contralateral side. 



At the end of the oblongata this degenerated tract is found in 

 the anterior colutnna of the cord (Plate XXI fig. 25 M) at the 

 sides of the decussatio pyramidum, and at the exit of the 2 th ante- 



