MOTOR CORTEX AND INTERNAL CAPSULE IN AN ORANG-OUTANG. 149 
(Paper read to the Royal Society, December 12, 1889), but whether we obtained 
complete results is questionable, since after we had observed the above-mentioned 
facts, and were proceeding to amplify and control them, the animal died suddenly, 
evidently from syncope. 
Summary and Review. 
We are now in a position to review the facts detailed above, and to examine into 
their real value. 
1. Condition of the Animal. 
{a) Health. —It had been in England about two months, and appeared to be in 
perfect health, and although the day before the experiment its appetite had begun to 
fail a little, to all appearances it was vigorous and healthy. It moved about in the 
vertical posture, and all its acts were performed completely, and with the deliberation 
special to the Orang. 
(6) Age. —The animal was estimated to be about 2^ years old. Since the animal 
was a young one, we wish it to be understood clearly that the facts which we put 
forward concerning the limitation ol representation are not necessarily typical, as it is 
possible that this may be more extensive in an older animal. Bearing on this point 
we may mention that we have found that, given the same species of Macacque 
Monkey, a more extensive representation occurs with a larger, i.e., an older, brain, 
and the converse also holds, but that the chief details and genei’al plan are the same 
under the two circumstances. 
Future investigation can alone decide this point. 
II. Vertical arrangement of the Representation oj each Segment in levels 
transverse to the Fissure of Rolando. 
In the Bonnet Monkey [Macacus sinicus) we have shown that the representation of 
the segments of the various parts of the body is arranged along the Fissure of Rolando 
in horizontal levels, and that the boundary lines of these pass across the fissure. In 
the Orang the same arrangement holds as is well seen in the photograph on Plate 21. 
This photograph is constructed by writing on an enlarged copy of fig. 1, Plate 18, the 
various foci of representation. If we place the segments in successive order as we 
see them in the Bonnet and the Orang, the relations are as follows :— 
