34 
PROFESSORS V. HORSLEY AND E. A. SCHAPER 
ill consequences resulted from tins, however, and when on the 5th day the dressings' 
were removed the wound was found to be completely healed. 
Result. — No muscular paresis. The animal seems to have some disturbance of 
visual consciousness of the images of objects which fall upon the left side of the 
retinae, for an object, such as a raisin, presented to it on the right side of the visual 
line is either not noticed or its nature is not readily recognised. This condition, which 
was very well marked at first, gradually improved, until three months after the 
operation it could be no longer determined. 
Second lesion. — Four months after the first operation the anterior half of the 
frontal lobe, including the orbital lobule, was removed upon the same side (the left) by 
a nearly vertical incision. The recovery was again rapid and complete. 
Result. — The only noticeable symptoms which were produced by the second lesion 
were (l) some paresis in the opposite arm ; and (2) an inability readily to turn the 
head to the opposite side. 
Third lesion. — Ten weeks after the second operation the whole of the left temporo- 
sphenoidal lobe was cut away, with the exception of the hippocampal gyrus, which 
was, however, injured considerably. In this operation the descending cornu of the 
lateral ventricle was freely exposed, and the hippocampus major was excised in the 
greater part of its extent. 
Result. — Immediately after the operation was completed there was some paralysis 
of the opposite limbs and defective sensibility on the opposite side of the body. But 
these results may well have been due to the temporary disturbance caused in the 
remainder of the hemisphere, by the loss of the support yielded by the temporo- 
sphenoidal lobe, and by the disturbance of the circulation in that half of the brain 
produced by the section and occlusion of many of its vessels. For, the next 
morning, on carefully testing for sensibility in various ways, no difference was 
determined upon the two sides of the body, and the paralysis of the limbs had 
disappeared, with the exception of the slight paresis of the upper limb, which had 
been left from the second operation. Vision for the images of objects falling upon 
the left half of the retinae was again impaired, and this impairment lasted some time, 
but how long was not accurately determined. Experiments devised to test the 
consciousness of auditory sensations reaching the opposite ear gave no definite results. 
The permanent result of these three ablations was, it will be seen, almost nil, 
although so much of the cortex of one hemisphere had been removed by them, 
Fourth operation. — Of the remaining part of the cortex, which included the 
angular gyrus, the parietal lobule, the central gyri, parts of the transverse frontal 
gyri, the marginal gyrus, the gyrus fornicatus, and the hippocampal gyrus, all but 
the two last-mentioned gyri were removed three months after the third operation. 
Result. — The result was the production of absolute hemiplegia with severe shock, 
from which the animal failed to recover, dying in the course of a few hours. 
The brain is represented in figs. 24a and B, Plates 3 and 4, but the representations 
