402 J. B. JOHNSTON 
disappears. It is this rostral end of the caudate nucleus that the 
writer identifies with the nucleus olfactorius anterior of Edinger 
and other authors. Following sections caudad, the sheet of 
olfactory fibers and cells scarcely disappear from the surface 
of the caudate until large cells appear in the lateral wall (fig. 26). 
Beneath the anterior end of the dorsal ventricular ridge this large- 
celled nucleus rapidly grows larger and the caudate smaller 
(figs. 22, 21) until the caudate is confined to a part of the floor 
of the ventricle adjacent to the ventral.groove (fig. 20). From 
this point the tail of the caudate extends caudally to the point 
where the middle ventricular groove bifurcates (fig. 15, 10). 
Before this point is reached the caudate is in connection medially 
with the anterior nucleus region of the thalamus over the crus 
and the stria medullaris (figs. 17, 18). The caudate then grows 
thicker and merges insensibly with the small-celled mass of the 
amygdaloid complex (nucleus of the lateral olfactory traet) 
(figs. 15, 16). The caudate then disappears from the sections, 
its place being taken by an area of neuropile. Horizontal and 
sagittal sections show in this position a cell-free zone bounding 
the caudate behind, which corresponds to the ventral arm of the 
middle ventricular groove as it bends down into the temporal 
horn of the ventricle. 
The caudate nucleus throughout its whole extent consists of 
small cells without regular arrangement. In its head portion it 
receives fibers from the olfactory tract and the medial forebrain 
bundle and gives fibers to the latter. In its tail portion are 
imbedded the stria terminalis and the great lateral olfactory 
projection tract of Cajal (figs. 48, 49). 
A peculiar vesicular structure found in the head of the caudate 
and in the lateral parolfactory nucleus should be described here. 
The greater number of these structures are found around the 
depression of the ventricle which extends down into the tuber- 
culum but some are found also in the lateral part of the caudate 
not far from the middle ventricular groove. At first sight these 
structures appear to be clusters of small cells arranged radially 
about a core somewhat like clusters of grapes about the stem. 
The clusters are elongated sometimes in the plane of transverse 
