OF DENISON UNIVERSITY. 
45 
small fibres, the immediate derivitives from a longitudinal bundle ap- 
pearing far caudad in the medulla and anteriorly covered by the longi- 
tudinal bundle of the fibrse arciformes. A smaller longitudinal bundle 
lies in the tuberculum Rolandii. The smaller root springs from a nu- 
cleus of large multipolar cells, like those of the facialis, lying below 
the floor of the ventricle. Its fibres curve dorsally, then ventrally and 
laterally to their exit. A part, however, of the. trigeminus fibres can 
be traced to the nucleus of the trochlearis. The cells of the trbchlearis 
nucleus are rounded and have few processes. The nucleus is elon- 
gate, and its fibres pass dorsally and caudad to the decussation in the 
valvula cerebelli. 
The Cerebellum. The medulla is connected with the cerebellum 
by the fibrse arciformes, there being no connection via corpora resti- 
form. The entire mass of the crura cerebelli ad corpora quadrigemina 
is derived from the cerebellum. 
In the pars peduncitlai is the pyramids appear quite lateral, while 
the anterior longitudinal fasciculi occupy a place between them and 
are only separated from each other by the substantia cinerea posteriora 
media. In addition there is a dorsal fascicle, and isolated fibres from the 
cerebellum. 
The gray substance between the longitudinal bundles is composed 
of a granular basis with small round or spindle cells and contains the 
following nuclei. The nucleus peduncularis consists of a lower por- 
tion composed of numerous small cells (.012-.016 mm.) and an upper 
smaller nucleus, with large multipolar cells (.04 mm). This nucleus 
occupies a lateral, ventral position below the nucleus of the oculomotor^ 
which its upper portion resembles. 
The corpora quadrigemina, thalami and optic region were not 
fully studied. , 
The corpora striata consist of mingled gray and white matter, the 
side nearest the ventricle being almost altogether gray, and the lateral 
portion united with the hemispheres is full of fibre bundles. The gray 
substance contains small round or fusiform cells with exceedingly fine 
processes and measuring .008-. 012 mm. 
The hemispheres are evidently zonary, the outer layer having a 
thickness of o. 5 mm. , followed by a gray layer reposing in turn upon 
the inner white. The gray matter of the cortex consists of three lay- 
ers of cells: first, an outer layer of small cells .008-. 016 mm. long, 
and closely aggregated; second, the layer of large cells .04 mm. long, 
