108 C. WINKLER. THE CENTRAL COURSE 



systema dorsale and in the descending and ascending roots, which 

 is nearly the same as after every rootsection. The nucleus of DEITERS 

 (Plate XVIII fig. 22 D and E) is not sensibly injured. 



A similar lesion was made in the case, from which the fig. 23 

 was taken. 



Now in all cases, in which the lateral trunk of the ventral and 

 intermedial system is sectioned there is found an intense degene- 

 ration in these systems. If compared with the degeneration after 

 rootsection, the difference is marked in several respects. 



l e . The degeneration in the systema ventrale and intermedium 

 is now found in alle the layers of the transverse ventral fibres. 

 In the layer of thick fibres (the stratum a) an enormous increase 

 of degenerated fibres is found as compared with those degenerated 

 in it after rootsection. (compare Plate XVIII fig. 22 B and Plate XXI 

 fig. 23 with Plate VIII fig. 15. N. 11, 12 and 13). 



In the layer of small fibres (the stratum 6) the same is the case 

 there exists no longer a layer of normal fibres (the stratum c] 

 between the ventral and intermedial degenerated systems, but a large 

 quantity of degenerate fibres is found between the two olivary 

 bodies. It is evident, that the at contra-lateral side to the operation 

 this layer shows a more important degeneration than at the same 

 side. (Plate XVIII fig. 22 B and Plate XXI fig. 23). And it is 

 also evident, that the dorso-latero-ventral medullary surroundings of 

 the olivary body present a very intensive degeneration at the operated 

 side, where as on the contrary in the medial hilus of the nucleus 

 olivaris of the opposite side it is more important than in the 

 homo-lateral. 



And the interpretation of these two facts is (a retrograde dege- 

 neration being excluded, because these degenerations are present 

 within a week) that in the olivary body originates a new system, 

 that leaves the nucleus at its medial hilus through the stratum c, 

 to seek the opposite side, whereas the degenerated ventral and 

 intermedial systems provide with fibres the homo-lateral oliva in its 

 dorso-latero-rnedial surroundings, and crossing the raphe provide 

 through the medial hilus the opposite one. The latter degenerated 

 part of the system covers the non degenerated one. Therefore it 

 has the appearance as if the medial hilus of the opposite oliva con- 

 tains nearly all degenerate transverse fibres and the homolateral nearly 

 all normal ones. Consequently there remains a layer of fibres in the 

 systema ventralis not degenerating if the ventral nucleus and the 

 systema intermedium be separated from the medulla. 



The intermedial system (the stratum d] also presents a degene- 



