58 BULLETIN OF THE LABORATORIES. 
not so largely charged with cells, the cuneate and clavate nuclei have 
disappeared, the lateral nucleus is still present, while the cells of the 
formatio reticularis are much more abundant and indicate the begin- 
ning of a large median nucleus which is quite conspicuous in the next 
section, (Plate XVI, Fig. 2, e.) This section is taken still farther cepha- 
lad and is chosen at the entrance of a few fibres of the ninth nerve root, 
{Fig. 2, Plate IX.) MDst of the fibres of this nerve turn soon after 
entering the medulla and pass into the longitudinal fasciculi; some, 
however, seem to lead direcdy into a small nucleus, a, which we term 
a nucleus of the ninth nerve. At this level we find the cells of the 
lateral nucleus increasing in number and size and forming quite a large 
aggregate which can easily be traced as the caudad extension of the 
seventh nerve nucleus. We have in this section also the first few 
fibres of the eighth nerve passing in above the restiform body to a 
large mass of gray matter densely packed with small cells, which we 
shall term the internal nucleus of the eighth nerve. 
The next section is taken at about the level of the middle of the 
entrance of the eighth nerve and at the union of the cerebellum with 
the medulla by the pedunciilus cerchelli., (Plate XVI, Fig. 3.) The 
eighth nerve enters as a large bundle, f, and just within the border of 
the medulla is located the nucleus of the root of the eighth nerve, c, 
composed mostly of rather small cells. 
Following the fibres as they pass into the medulla we find that 
some of them pass dorsad to the restiform body, y, and enter Deiter’s 
nucleus, b, in the peduncle of the cerebellum and some turn directly 
into the cerebellum. Of those fibres which pass ventrad to the resti- 
form body, part turn dorsad and enter Deiter’s nucleus from below and 
perhaps pass through the nucleus into the cerebellum. 
The remaining fibres pass through a reticular formation and enter 
the internal eighth nucleus which is on the floor of the fourth ventricle 
at d. Fig. 3, Plate XVI. The cells of Deiter’s nucleus are of the or- 
dinary multipolar type, measuring about .05 mm. in length. The en- 
trance of the eighth root is also shown on Plate XVI, Fig. 6, as is 
seen in a longitudinal section taken parallel to the base of the medulla. 
As most of the fibres pass dorsad upon entering the medulla the only 
nucleus of the eighth shown at the level of the entrance is the nucleus 
of the root, b., of the figure. 
Besides the nucleus of the raphe and adjacent formatio reticularis, 
e, of the section, (Plate XVI, Fig. i,) the only other group of cells 
