THE MEDULLA OBLONGATA AND TEGMENTUM OF THE PONS. 199 



fibres. Numerous internal arciform fibres take their origin here, 

 and, passing through the motor area of the tegmentum (as the 

 space between the posterior horn and the inter-olivary layer is 

 called), enter the raplie and cross to the opposite side. 



The fibres of the cerebello-olivary tract follow an exactly 

 similar course for a certain distance. In the figure they are 

 represented by dotted lines, but in reality the two kinds of in- 

 ternal arciform fibres cannot be distinguished in the adult. 



FIG. 119. 



The cerebello-olivary portion of the restiform body. The fibres terminate mostly in 

 the fleece of the corpus dentatum. That part of the restiform body which is left white 

 indicates the situation of the spinal-cord portion. 



Ill the median line, of course, all these fibres decussate 

 with those coming from the opposite side. This line, with its 

 numerous decussations, is called the raplie, 



The inter-olivary layer, or layer of the fillet, contains at 

 this level, besides the tracts which ascended in the antero-lateral 

 column, the greater part of those originating in the nuclei of 

 the posterior columns. 



Notice, also, the fibres passing from the layer of the fillet 

 to the nucleus of the vagus of the opposite side. They are the 



