74 C. WINKLER. THE CENTRAL COURSE 



or three weeks after the operation, brings degeneration in fibres 

 belonging to the two here described tracts. 



In a frontal series after rootsection studied with MARCHI method 

 it is easy to see (Plate VIII fig. 15 N. 12andN. 13) that on the 

 operated side, degenerated fibres detach themselves from the surroun- 

 dings of the oliva superior (from the place, where ventral and inter- 

 medial system are meeting) and seek their way between the sensible 

 and motor nucleur of the V th nerve to the utmost lateral and super- 

 ficial layer of the lemniscus covering the pedunculus cerebelli superior. 



From there , turning distally , they may be traced (Plate VIII 

 fig. 15 N. 11, 10, 9 and 8) to the nuclei tecti mediates cere- 

 belli at the same and at the opposite side. But , it may also be 

 seen , that the root-fibres of the systema ventralis , having crossed 

 the raphe (and on their way remaining for the greater part in the 

 ventral teginentum nuclei) still are present in the field between 

 oliva superior and spinal root of the V th nerve of the opposite side. 

 There they meet again fibres of the intermedial system, which also 

 have passed through the raphe. On this way also fibres are going 

 into the opposite antero-lateral tract (Plate VIII fig. 15 N. 12 

 and 11), however in much smaller quantity as at the same side. 



More easily the degeneration in this tract after root-section may 

 be traced in horizontal sections. (Plate X fig. 16 G, II and I, 

 plate X fig. 16 K, L, M, N, Plate XIV and XV fig. 14 A E). 

 In fig. 16 at H, the entrance of the degenerated roots is found, 

 covered with black granules. But the degenerated fibres in the 

 lateral lemniscus have already appeared much more ventrally and 

 in Plate IX fig. 16 E they detach themselves from the oliva superior. 



These are crossed fibres from the systema ventrale. 



But a new increasing of the degenerated fibres in the lateral 

 fillet is found in Plate XI fig. 16 K. These homolateral fibres are 

 coming from the stratum latero-dorsale along the queer-sectioned 

 bracchium pontis. In a more dorsal section (Plate XI fig. 16 M 

 in 1.1.) the superficial layer of the lateral lemniscus, medially bor- 

 ' dered by the nucleus dorsalis lemnisci, begins to cross the superior 

 cerebellar peduncle and still more dorsally (Plate XI fig. 16 N). 

 These fibres enters in the same-sided and opposite nuclei tecti 

 mecliales of the cerebellum. 



In fig. 14 (Plate XIV and Plate XV) the direction of the hori- 

 zontal section is better fit for demonstration. The preparation (Plate 

 XIV fig. 14 A) at first touches the degenerated root-entrance, and 

 degenerated fibres (entered in more ventrally situated sections) are 

 already in the lateral lemniscus on both sides; lying close medial 



