MEDULLA OBLONGATA AND TEGMENTUM OP THE PONS. 393 



Before ascending farther it will be well again to consider the above- 

 mentioned,.but not particularly described, tegmental region, and to learn its 

 position and relations in this level. One feature, the nucleus reticularis teg- 

 menti, which lies with the fibers of the substantia reticularis scattered over 

 the region between the raphe and the facialis root, is not included in the 

 illustrations, in order to preserve their clearness. It is to be found, how- 

 ever, in all the sections thus far considered. 



The accompanying Pig. 350 follows the sections Just described, and is 

 to demonstrate how the facialis turns about after coursing a short distance 

 ventrally, and how the direct sensory cerebellar tract now passes upward 

 into the cerebellum. 



Fig. 250. — Section at the place where the inner division of the corpus 

 restiforme merges into the cerebellum. 



In the cerebellum are to be seen in this level the peduncles coming 

 from in front. 



When the acusticus, the facialis, and the abducens leave the tegmentum, 

 the cross-section appears naturally much more simple. 



We come to the place of entrance of the nervus trigeminus, and first the 

 motor nucleus of the trigeminal appears in the continuation of the nucleus 

 facialis, th6ugh somewhat more dorsal. From it arises, also by a slight 

 "knee," the motor root, the portio minor, supplying the muscles of mastica- 

 tion. Probably there pass with it fibers coming from the opposite motor 

 nucleus, which cross over the raphe. 



With the motor trigeminus, course, also, fibers from the pons, which 



