212 



LECTURES ON THE CENTRAL NERVOUS SYSTEM. 



where the fillet begins to turn upward there are found some 

 ganglion-cells imbedded in it (lateral nucleus of the lemniscus, 

 Obersteiner). This group can be traced upward to the upper 

 nucleus of the fillet, which is situated on the outer border of the 

 substantia nigra. Those fibres of the fillet which lie nearest the 

 raplie form a separate bundle. This arises from the pyramidal 

 portion of the crusta. It was shown in the seventh lecture how 

 this bundle became separated from the pes, passing around its 



ufa. 



FIG. 128. 

 Section through the upper pontine region of a foetus in the ninth month. 



Bindtarm, Anterior cerebellar peduncle. Briicke, Pens. Schleife, Fillet. 



whole internal border and extending to the median side of the 

 fillet. Spitzka's studies in comparative anatomy have made it 

 very probable that this little bundle contains the central tracts 

 of the motor cranial nerves. We may easily ascertain that 

 fibres are continually given off from it which ascend in the 

 raphe, and can see that, at the upper end of the raphe, fibres 

 pass over beyond the middle line to the nerve-nuclei. This is 

 shown most clearly with reference to the hypoglossal nerve. 



