140 C. WINKLKK. THE CENTRAL COURSE ETC. 



3. Fibres descending in the medial part of the formatio reticu- 

 laris oblong ata. 



These fibres are known as the descendant tract of DEITERS or 

 as the fasciculus vestibulo-spinalis. In the cord they take a position 

 at the peripherical margin of the lateral column , near the issuing 

 roots, which penetrate queer through it. The same tract is by far 

 less important at the contra-lateral side. It may also be followed 

 through the medulla till the sacral part of it. This tract may be 

 called a lateral descending octavo-spinal tract. 



4. Fibres descending in the ,,aberrirendes Seitenstrangbiindel" . 

 They are only few descending fibres in the rubro-spinal tract. 



In the oblongata they are situated in the ,,aberrirendes Seitenstrang- 

 biindel". In the cord they are found in the posterior part of the 

 lateral column in the triangle between formatio gelatinosa cornu 

 posterioris, pyramidal tract and PLECHSIG'S dorsal cerebellar tract. 



The same tract is found contra-lateral by far less important. 



They may also be followed through the medulla till its sacral 

 part. This tract may be called a dorsal descendent octavo-spinal tract. 



The most important result of this anatomical study however is, 

 the following. 



The nervus octavus , with a small portion of primary fibres 

 with a larger postion of secundary fibres , is in contact chiefly. 



1. with the collateral nuclei VI, IV and III. 



2. with the contralaleral nucleus VI. 



3. with the collateral motor columns of the medulla through its 

 whole length. 



