FIBRES OP THE INTERNAL CAPSULE OP THE BONNET MONKEY. 
87 
Description of Plates. 
PLATES 5.-9. 
Fig. 1. This figure consists of a number of drawings of the internal capsule and basal 
ganglia of the left side in horizontal section, corresponding to the eight 
different levels into which we have grouped our observations, and enlarged 
twice the natural size. 
a. = Anterior commissure. 
C. =■ Caudate nucleus. 
F. — The point of fusion of the lenticular and caudate nuclei in the 
basal grey matter. 
i. = Inner zone of the lenticular nucleus. 
1. = Middle zone of lenticular nucleus. 
L. = Outer zone of lenticular nucleus or putamen. 
O. = Optic thalamus. 
Figs. 1, A.-R., give on tracings of the outlines of fig. 1, the limitation of the fibres, 
excitation of which produced a particular movement, the character of which is 
indicated in the margin. 
Figs. 4, 5, 6 (on Plate 6). Views of a dissection of the hardened brain of a Macacus 
sinicus, in which almost the whole of the hemisphere has been cut away, 
leaving only the basal ganglia to show their relations to each other and to the 
internal capsule. Fig. 4 is viewed from the inner or ventricular side, fig. 5 
from below, and fig. 6 from the outer side. 
A.a. = Anterior and ascending division of prsefrontal fibres, lying in the 
deep groove between the caudate and lenticular nuclei. 
a.c. = Anterior commissure. 
Ch. = Optic chiasma. 
Cb. = Cerebellum. 
H. = Horizontal fibres of prsefrontal portion of capsule. 
Hi. — Hippocampus major. 
Gy. Hi. = Gyrus hippocampi. 
C.q. = Corpus quadrigeminum. 
l.m. = Outermost lamina medullaris. 
s.d. = Superior and descending division of praefrontal fibres. 
Ca. = Caudate nucleus. 
Pu. = Putamen or outer zone of lenticular nucleus. 
P.F. = Excitable (“ motor ”) or fronto-parietal fibres. 
L. — Posterior limit of excitable fibres. 
