222 RALPH EDWARD SHELDON 
diencephalicus can be traced only a short distance caudal to the 
level shown in fig. 101, where it ends mesal to the nucleus rotun- 
dus at the level of the nucleus posterior tuberis. The tractus 
hypothalamo-olfactorius medialis holds a position near the median 
line at this point, while the tractus olfacto-thalamici, pars dor- 
salis and pars ventralis are looping ventro-laterally, to pass below 
the nucleus rotundus (fig. 101) to their termini in the nuclei sub- 
rotundus and posterior thalami, respectively (figs. 115, 116, 122, 
139). ) 
(7) Fasciculus lateralis hemisphaerii. This has been known 
from the time of the first workers on the microscopic anatomy of 
the teleostean brain. It has been called by various names since 
the time of Stieda: pedunculus cerebri, by the earlier workers, 
‘basale Vorderhirnbiindel’ by Edinger, ‘faisceau basal’ by Catois, 
‘tractus strio-thalamicus’ by Johnston, Goldstein, Kappers, ete. 
In practically all forms it consists almost entirely of unmedul- 
lated fibers, although it is one of the largest and most constant 
bundles of the brain. Earlier workers considered that it was made 
up exclusively of descending fibers from the cells of the corpus 
striatum, ending in the diencephalon. Edinger (’88) states 
simply that the fibers originate in the ‘Stammganglion’ and end 
in the ventral part of the ‘Zwischenhirn.’ He thinks it very likely 
that part of the fibers decussate in the anterior commissure. 
C. L. Herrick (’91 and ’92) divides the basal forebrain bundle 
into two parts, both descending, a ventral peduncle arising from 
the rostral part of each basal lobe and ending in the caudal part 
of the hypoaria, and a dorsal peduncle originating in the caudal 
part of each lobe, and ending largely in the nucleus ruber and sub- 
thalamicus (nucleus rotundus, sensu lato). Johnston (’98) iden- 
tifies three sets of fibers in the bundle, a tractus strio-thalamicus 
medialis, lateralis and ventralis. Johnston here includes under 
the name tractus strio-thalamicus ‘‘all fibers connecting the fore- 
brain with the ventral portion of the diencephalon.” His tractus 
strio-thalamicus ventralis is evidently a part of the medial fore- 
brain bundle, as is also a portion of the tractus strio-thalamicus 
medialis, consisting of ascending fibers from the thalamus to the 
epistriatum, decussating in the anterior commissure. John- 
