224 Cc. JUDSON HERRICK 
This part of the frog brain has been called corpus striatum by 
some previous writers (including myself, ’10). But not by 
Gaupp (99, p. 107), who with his usual acumen recognizes 
that only the undifferentiated middle part of the ventrolateral 
area which is closely associated with the lateral forebrain bundle 
is with certainity to be compared with the ‘basal ganglia’ of 
higher vertebrates. Further than this he was not able to carry 
his analysis of this region. 
The true corpus striatum of the frog, as already indicated, 
occupies the ventrolateral quadrant of the cerebral hemisphere, 
chiefly rostrally of the interventricular foramen, and is charac- 
terized by its functional connection with the lateral forebrain 
bundle (figs. 2 to 6, 14, 15). Its more rostral portion is one of 
the least differentiated regions of the hemisphere. Its caudal 
end at the level of the foramen is expanded to form a highly 
differentiated nucleus containing but few neurons and a very 
dense neuropil (figs. 5, 6, 17, 20, 23) derived chiefly from the 
lateral forebrain bundle. From this neuropil arises the decussa- 
tion of the lateral forebrain bundle (figs. 6, 17), which is com- 
posed largely of collaterals of the fibers of this bundle. 
The cell bodies of the neurons of the amygdala tend to be 
accumulated on the medial border, though some are distributed 
throughout. They are sparse or absent on the lateral side. 
This cellular area is confluent dorsally with that of the pyriform 
lobe, ventrolaterally with that of the corpus striatum, and ventro- _ 
medially with that of the lamina terminalis and preoptic nucleus 
(figs. 4, 5), though the limits between these regions are rather 
sharply defined. 
As seen in Golgi preparations (fig. 13), some neurons of the 
amygdala have large rounded cell bodies and some are very 
small. Their dendrites spread widely and irregularly throughout 
the nucleus. The neurons of the adjacent corpus striatum tend 
to be larger and more irregular in shape. In most of our prepara- 
tions where the cell bodies and dendrites are impregnated their 
axons are not, and conversely, so that it is difficult to be sure 
of the connections of individual cells. - The impression gained 
from the preparations is that the larger elements send their 
