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VI. A Record of the Residts obtained, by Electrical Excitation oj the so-called Motor 
Cortex and Internal Capsule in an Orang-Outang (Simla satyrus). 
By Chaeles E. Beevoe, M.D., E.R.C.P.. and Victoe Hoesley, B.S., F.R.S. 
{From the Laboratory of the Brown Institution.) 
Received June 5,—Read June 12, 1890. 
[Plates 16-21.] 
Contents. 
Page. 
Introduction.129 
Anatomy of the Cortex under observation.130 
Method of Investigation.133 
Results of Excitation— 
A. Cortex. 134 
B. Internal Capsule.147 
Summary and Review.149 
Inteoduction. 
Having been occupied with the study of the minute representation of motor 
function in the cortex of the Bonnet Monkey {Macacus sinicus), it seemed to us 
extremely necessary to investigate the character of such representation in the cortex 
of an anthropoid Ape, in order that we might form a more correct estimate of the 
mode of localisation in Man. A comparative study of the brains and habits of the 
more easily obtainable anthropoids showed clearly that for our object the Orang was 
more suitable than the Chimpanzee, in being likely to afford results nearer to those 
presumed to exist in Man. We therefore procured a young Orang which, in the 
opinion of Professor D. J. Cunningham, of Trinity College, Dublin, was about 
years old. 
In addition to excitation of the cortex, we also investigated the movements obtained 
by stimulating the fibres of the internal capsule. 
We shall therefore arrange the facts as follows :• 
Anatomy, 
Method of Investigation. 
Mucccxc.—B. s 
12.12.90. 
