651 



r 





.> 



o 



s 



Fig. 4. Nucleus motoiius commissuralis vagi, c, Canalis centralis 



lateral [)aft grows out into a curved point. Its base is then directed 



medio-dorsally, so that it moi"e or 

 '.• 1. ' '\ less assumes the form of a sickle. 



In a great number of sections we 



see that many cells have shifted 



ventrallj, so that not iinfrequently 



an actual bridge has been formed 



between it and the nucleus hypo- 



glossi. It contains in this region 



90—100 cells (fig. 5). More front- 



i ' , ^ ' ' •' ally the ventro-lateral pole sinks 



^ - more and more, and the nuclei 



"*. diverge to right and left. The 



* < ^ i ^ development of the nucleus is not 



^ ^ equal everywhere. At times it is 



i J ^V remarkably strong, with a large 



i^* _,•> "^JL '^3'P^ °' ^^'^ predominating. At 



other places the number of cells 

 Fig. 5 Sickle-shaped dorsal motor vagus jy mudj smaller and the cell group 



nucleus; connection with nucleus XII. u„ , „„ , t *• h 



shows gaps. In a tollowing region 



the form of the nucleus is irregular, as, besides the cells which have 

 moved ventrally, some cells have also dropped out in a dorso-lateral 

 direction ; these are frequently classed in separate cell groups. Near 

 the calamus the nucleus becomes clumsy in form, separate loca- 

 lisations can now be clearly seen, owing to cell groups severing 



