E. Lindon Mellus Dati 
but there is no degeneration in the genu of the same side, and, of course, 
the corresponding mesial segment of the crus is uninjured. On the con- 
trary, in “ Cas Schweigoffer ” (Vol. 2, p. 185), by which he appears to 
prove that the origin of the fibers of the genu and of the mesial segment 
of the crus is in the cortex of the frontal and Rolandic operculum, the 
conditions are quite reversed. The genu of the internal capsule and the 
mesial segment of the crus are completely destroyed, while there is but 
slight evidence of degeneration in the anterior segment of the internal 
capsule. In this case it seems quite evident that but little of the degenera- 
tion in the genu could have come from the anterior segment. Here, as 
well as in the case reported by v. Monakow, it seems quite reasonable to 
suppose the degeneration in the genu and the mesial segment of the crus 
may have been dependent upon the destruction of sub-cortical tissue in 
the island of Reil and that these fibers may have their origin in the cortex 
or the upper and anterior portion of the island. V. Bechterew,’ on the 
authority of Zacher, suggests such an origin, and many findings point 
in that direction. Fibers from that cortical area would find their way 
to the genu over and through the thin crest of the lenticular nucleus. 
Another point worthy of special notice in these experiments is the 
passage of fibers from the frontal lobe directly through the thalamus 10 
the gray matter surrounding the aqueduct. Some of these pass from 
the anterior segment of the internal capsule directly into the thalamus; 
others, sweeping around the genu, through the globus pallidus, reach 
the posterior segment of the internal capsule, and, after a shorter or 
longer course with the capsular fibers, pass into and through the thalamus 
to the same destination. Some of these fibers (perhaps all) seem to come 
from the pre-Rolandic cortex of the frontal lobe, and their origin and 
course suggest that they may rise in cortical areas representing eye move- 
ments, and that they take this course as the shortest route to the nuclei 
of the oculo-motor nerves. It also has the advantage of furnishing 
collateral connection with the nuclei of the thalamus, sometimes supposed 
to be active agents in emotional reflexes (Bechterew). It will be 
noticed that the coarser of these fibers follow the capsule into the crus. 
These fibres also find their way to the gray matter around the aqueduct 
after leaving the crus. 
One set of fibers degenerating in these experiments suggests some rather 
unexpected connections of the frontal lobe with the basal ganglia—that is, 
®Leitungsbahnen im Gehirn und Riickenmark, 2d German Edition, Leip- 
sig, 1899. 
