346 ELIZABETH CAROLINE CROSBY 
Ventro-lateral large celled area (Johnston’s nucleus lentifor- 
mis) (figs. 7 to 10, 17 to 19). This nucleus appears as a group of 
cells just dorsal to the small celled area at the anterior of the 
hemisphere and laterally close to the nucleus of the lateral ol- 
factory tract. Farther caudad it is partially separated from the 
ventro-lateral small celled area (Johnston’s caudate) by a spe- 
cial fascicle of the lateral forebrain bundle. In the posterior 
part it forms a heavy ridge of cells over the dorsal and dorso- 
lateral portions of the small celled area. It disappears in front 
of the posterior end of the latter area at about the level of the 
foramen of Monro. The larger size of the cells of the ventro- 
lateral large celled area makes it easy to distinguish this nucleus 
from the ventro-lateral small celled area. 
Intermedio-lateral area (figs. 7, 8). This area is found at 
the level of the posterior part of the infolding of the general cor- 
tex and in the region just caudad to that infolding. The inter- 
medio-lateral area is ventral to the dorso-lateral area, dorsal 
to the ventro-lateral areas and medial to the nucleus of the 
lateral olfactory tract. It lies in so close relation with this last 
nucleus especially in its more anterior extent that it is not prac- 
ticable to attempt to draw any sharp boundary line between 
them. The intermedio-lateral area is separated from the ven- 
tro-lateral areas by a cell free zone in which are fibers which 
belong in part at least to the lateral forebrain system. A sulcus 
in the ventricular wall indicates the position of the boundary 
line between the intermedio-lateral and ventro-lateral area. 
The anterior portion of the former area is separated from the 
dorso-lateral area by a cell free zone but the two areas fuse into 
one, behind the level of the infolding of the general cortex. So 
far as the evidence goes, the intermedio-lateral area appears to 
belong with the dorso-lateral area. Possibly it is a representa- 
tive of some part of the striatum complex of higher forms. 
Nucleus of the lateral olfactory tract (figs. 5 to 10, 12, 16 to 19). 
This nucleus can be distinguished from the other cell masses in 
the lateral wall of the hemisphere by the smallness of its cells. 
It begins as a small cluster of cells scattered along the inner 
border of the cortex of the pyriform lobe and between that cor- 
