THE FOREBRAIN OF THE ALLIGATOR 371 
ular tract arise from the more anterior part of the nucleus of 
the lateral olfactory tract, from the cortex of the pyriform lobe 
in that region, and possibly from the nucleus of the diagonal 
band of Broca. The fibers run medialward in the ventral part 
of the forebrain, mingling in part with the fibers of the diagonal 
band of Broca, which lie on the ventral surface of the brain just 
external to them. Near the medial border of the hemisphere 
the anterior cortico-habenular tract turns dorsalward over the 
ventro-medial nucleus and occupies a position in the angle be- 
tween that nucleus and the lateral forebrain bundle (figs. 20, 
21). In this angle it is joined by a fiber band which extends 
along the medial surface to the caudal portion of the nucleus 
ventromedialis among the cells of which nucleus a part of the 
fibers can be traced (fig. 20). These two components of the 
tract are joined on their medial surface, at this angle between 
the ventro-medial nucleus and the lateral forebrain bundle, by 
the lateral olfacto-habenular tract and the tracts run dorsalward 
together and enter the stria medullaris and so reach the 
habenula. 
Accompanying the fibers of the anterior division of the lateral 
cortico-habenular tract from the nucleus of the lateral olfac- 
tory tract and the pyriform lobe is a small bundle of fibers aris- 
ing from the same regions, passing dorsal to the ventro-medial 
nucleus. Instead of entering the angle, however, between that 
nucleus and the lateral forebrain bundle, this band of fibers 
runs farther medialward and joins the medial forebrain bundle 
(figs. 20, 21). It runs caudalward in this bundle. Its posterior 
distribution is not certainly known as its fibers cannot be dis- 
tinguished from others of the medial forebrain tract. Unless 
it changes its relative position, however, it probably ends in 
the hypothalamus, but nothing definite is known of its ending. 
In its connections within the hemisphere and in its relative po- 
sition in respect to the forebrain bundles, this fiber tract from 
the pyriform lobe region shows several points in common with 
the tractus pallii of lower forms (Herrick, 710). It is possible 
that it and the olfactory projection tract of Cajal may be the 
