MEDULLA OBLONGATA AND TEGMENTUM OF THE PONS. 



385 



may observe fibers entering it, which come from the dorsally-placed nucleus 

 acustici dorsalis, which here begins to be visible, while in the following sec- 

 tion may be recognized a very large center, the ventral — formerly anterior — 

 nucleus of the acusticus. One can see already in this section how it is placed 

 between the cerebellum and the restiform body. A protuberance lateral to 

 it, on the surface of the medulla oblongata, is called the tuberculum acusti- 

 cum. 



Passing upward again, we come to the place where the first fibers of the 



Fig. 244. — The relations of the oblongata to the Inferior edge of the pons. 

 Dir. sens. Cereb. B., Direct sensory cerebellar tract. Centr. H. B., Central teg- 

 mental tract. 



pons Varolii are ventrally superimposed on the pyramids, coming, as they 

 do, from the cerebellum. 



All the following sections, therefore, will show in the ventral portion 

 the greatly intertwined crus portion of the pons. It changes relatively little 

 up as far as the levels described in Chapter XX. 



Much more complicated than the crus portion is the tegmental part of 

 the pons. Here begins a locality of the brain in which in a relatively very 

 narrow space are crowded together important structures, the region into 

 which passes the acusticus, and from which arise the facialis and abducens. 



