VI. A record of the results obtained, by electrical excitation of the so-called motor cortex and internal capsule in an orang-outang (Simia satyrus)

Abstract

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 21/2 years old. In addition to excitation of the cortex, we also investigated the movements obtained by stimulating the fibres of the internal capsule.