104 C. WINKLER. THE CENTRAL COURSE 



in ventral direction. In this way there may pass a few of them 

 in the so-called fasciculus praedorsalis. 



The intermedia! system however, at the moment of crossing the 

 raphe, also sends a few of its fibres distally in a longitudinal direction. 



Therefore in distally situated frontal sections of the oblongata, 

 some degenerate fibres are found, in the region, that is called the area 

 or fasciculus praedorsalis. Mostly they appear at the same side but a few 

 in that of the opposite side of the root-section. In this area they 

 are found in frontal sections as black globules , dispersed near the 

 raphe, dorsally from the lemniscus medialis (principalis) and ven- 

 trally from the fasc. long. post. And in horizontal sections there 

 are found scarcely longitudinal fibres, degenerated in this region 

 near the raphe (Plate IX fig. 16 E, Plate X fig. 10 F and G). 



Now it must be repeated that Marchi-method here has reached 

 its limits, that the distal degeneration of longitudinal fibres in the 

 fasc. long. post, and in the fasc. praedorsalis is not very im- 

 portant. But soon I will demonstrate, that a very important secun- 

 dary way may be traced through the fasc. praedorsalis into the 

 spinal cord. 



In this way I believe root-fibres to be found as well in the 

 distal path of the tractus DEITERS descendens, as in that of the 

 fasciculus longitudinalis posterior, tracts, which are both myelini- 

 sated in the elder foetus of rabbits. 



A sufficiently large number of degenerate fibres however, enters 

 in proximal direction among the longitudinal fibres of the fasc. 

 long, posterior. These fibres are nearly all found homolaterally 

 and may be followed to the same-sided nucleus of the IV th -and 

 that of the III th nerve, which in this way are connected with 

 direct root-fibres of the N. octavus. But not in this way only. 



Better than in frontal sections, it is seen in horizontal sections 

 (Plate XIV fig. 14 B) of the normal, as well as of the young born 

 animal, that other fibres of the tranversal dorsal layer, are going 

 proximally towards the fasc. long. post. 



In a slight ventrally curved proximal bundle, issued from the 

 dorsal transverse fibres and medullated in the elder foetus of rabbit 

 (which in distal sections reached the fasc. long, posterior in the level 

 of the genii of the n. VII (Plate XII fig. 17, A, B and C)), somewhat 

 laterally from the fasc. long. post. (Plate XII fig. 17 A. Plate VI 19 C) 

 rootfibres reach the Nucleus N. IV and N. Ill, and provide in these 

 nuclei. In this proximal bundle of the transversal dorsal fibres a 

 slight but evident degeneration is found after root-section. The dege- 

 nerate fibres lying there may be traced into the IV th and III th 



