182 C. WINKLER. THE CENTRAL COURSE 



Fig. 20 D. A horizontal section through the entrance of the octavus-roots and the 

 knee of the facial nerve. The section demonstrates the degenerated tractus 

 BETTERS ascendens , the degenerated fasciculus longitudinalis posterior and 

 the transverse fibres, passing through the contralateral nucleus BETTERS 

 and the beginning of the contralateral tract of BETTERS . with slight 

 degeneration. 



Pig. 20 E. A horizontal section touching the exit of the V th nerve. It demonstrates 

 the degenerate homolateral tract of BETTERS round the facial root, and 

 more distally the degeneration in the praedorsal tract and in the rubro- 

 spinal tract. 



Fig. 20 E. A horizontal section touching the facial nucleus and olivary bodies, with 

 degeneration in the three descendent longitudinal tracts, the praedorsa] 

 tract, the dsscending BEITEKS tract, and the rubro-spinal tract. 



Fig. 21. Sections at different levels of the medulla, to demonstrate the farther 

 course of the descending tracts in the cord. 



In these preparations, the lesion touches the fillet, 

 and an injury of the rubro-spinal tract at the level of the 

 issuing trigeminus-root cannot be excluded. 



PLATE XVIII. 



Fig. 22 A H. A series of frontal sections, through the central 



system of a rabbit, eleven days, after a transverse section 



through the left lateral trunk of the corpus trapezoides. 



In fig. 22 B D the injury of the system is indicated 



by the letter x. 



In fig. 22 A. The section falls through the corpora quadrigemina anteriora. in the 

 right lateral fillet fibres to the ventral layer of the nucleus corp. 

 quadr. posterioris are degenerated. A slight transverse degenerated 

 layer of fibres ventrally from the nucleus or the IV th nerve is seen 

 (PROBST bundle). 



Fig. 22s. This section, through the proximal parts of the olivary bodies, is 

 touching the proximal end (by x) of the incision. 



The corp. trapezoides and the systeina ventrale nervi octavi is nearly 

 totally degenerated. 



Pig. 22 c. The section touches the injury by x. Between the lesion and the 

 //aberrirendes Seitenstrangbiindel" the intact medic-ventral end of the 

 V th spinal root is found. The dorso-lateral fibres of this root are sectioned 

 and degenerated distally, as is seen in all distal sections. Here, in 

 the aberrirendes Seitenstrangbiindel , a tract degenerating distally is 

 found (rubro-spinal bundle), and the slight degeneration in the des- 

 cending tract of BETTERS and in the praedorsal tract is evident. 



Fig. 22 D. The section touches the entrance of the ventral octavus-root. 



Fig. 22 E. The entrance of the distal octavus root. 



Fig. 22 P. A section through the proximal i 



-p. . ,, V , , part of the XII th nucleus. 



.tig. 22 G. A section through the distal ( i 



Fig. 22 H. A section through the distal end of the oblongata. 



In fig. 22 D H. The area's of the rubro-spinal tract, of the descending tract of 

 BETTERS and of the praedorsal tract, are marked by degeneration in 

 the different levels , where the section touches them. 



In this case it is not probable that the rubro-spinal 



