OF DENISON UNIVERSITY. 
69 
nective tissue fibrils due to the structure just described. A bundle 
passing from above nearly parallel to the median line and obliquely 
caudad, seems to be Meynert’s bundle, as seen in longitudinal sections. 
Sections caudad (Fig. 4,) indicate the rudiment of the ventricle 
of the optic lobes so prominent in reptilia, etc. The fibre tract above 
this may be distinguished as the commissure of the optic lobes or 
simply optic commissure. 
Sections posterior to the nates and therefore passing through the ' 
testes near their base and nearly parallel to the base are, because of their 
position, at right angles to the nates. 
(Section immediately following Fig. 5, Plate IX, VI-^:-2 5.) The 
outline of the section is approximately semi-circular, the upper surface 
being truncate. The aqueduct which lies near the dorsal aspect is 
rhombic with the angles produced in the horizontal and vertical planes. 
The bridge is abruptly separated from the peduncular portion, except 
ventrally, where its fibres separate into fascicles inter-digitating with 
each other and leaving intervals which are filled with densely nucleated 
gray matter. The dorsal half of the section is composed of nearly 
homogeneous, finely nucleated gray matter, in which are no well-lim- 
ited nuclei-portion of testes. The latero-dorsal angles are occupied 
with obscure and ill-defined longitudinal tracts. The lateral aspects of 
the dorsal half are occupied by arching fibre tracts passing ventrad 
which seem with little doubt to be backward continuation of fibres 
descending from the nates. The tract disappears by passing caudad 
out of the section at a point dorsad to a well-defined nucleus lying just 
laterad to the ventral pyramids, which latter here form strong bundles 
with oval sections. The nucleus just mentioned (pons nucleus,) is 
similar to the gray matter filling the interspaces between the pons 
fascicles. 
Upon the dorsal aspect of the ventral pyramids is another small 
nucleus, having a narrow encircling band of gray, with the longer 
axes of the cells parallel to the plane of section and at right angles to 
the fibres. 
Above this nucleus is a small circular cluster on either side near 
the median line, consisting of larger multipolar cells. Still dorsad and 
in the ventral aspect of the dorsal longitudinal fascicle, is a larger nu- 
cleus on either side, likewise circular in outline and densely packed 
with cells of median size and irregular contours. The area imme- 
diately surrounding the aqueduct is homogeneous and sparsely sprink- 
