LESION OF DIFFERENT REGIONS OF THE CEREBRAL HEMISPHERES. 553 
Experiment 30 (Plate 33, figs. 149-156). 
In this case the right hemisphere was exposed over the incisura prse-occipitalis, and 
an incision was made with the cautery along the posterior border of the middle temporo- 
sphenoidal convolution, and another from the upper extremity of this incision horizon¬ 
tally inwards below and parallel to the second occipital sulcus, the parts between the 
two incisions, viz., the inferior temporo-sphenoidal convolution and hippocampal region, 
being considerably broken up. 
An hour after the operation the animal was able to sit up and use all its limbs, 
though the left seemed awkward. It could use its left hand to pick up pieces of food, 
but occasionally let them drop. Sight to the left was retained, as the animal put out 
its left hand to lay hold of, and push away a stick made to approach its left side. It 
was also seen to pick up a piece of potato lying to its left side. Hearing on the left 
side was undoubted, the slightest scratching or similar sound near the left ear causing 
the animal to turn sharply round and look. 
Tactile sensibibility was much impaired, but not entirely abolished, on the left side. 
Heat caused much less indication of painful sensation on the left as compared with the 
right. 
Next day the animal was in good health and vigour. 
Sight and hearing were equally acute on both sides. There was no motor paralysis. 
Tactile sensibility was still impaired. The fingers of the left hand could be touched 
gently, or rubbed, without attracting the animal’s attention ; whereas the same on the 
right caused the animal to look or move away from its position. The reaction to heat 
was less active than on the right side—determined by the grimaces and movements of 
the animal. 
On the fourteenth day it was impossible to determine any difference as regards the 
tactile sensibility on the two sides. The animal seemed in perfect health. On this 
day the left occipital lobe was exposed posteriorly, and a wire cautery pushed through 
it downwards and forwards, approximately in the course of the hippocampal region. 
An hour after the operation, while the animal was sitting up, but leaning towards 
the right, thermal stimulation of the left and right side respectively showed that, 
though severe stimulation caused signs of feeling on the right, yet a degree of heat 
which excited lively signs of feeling on the left was allowed in contact with the right 
hand and foot without causing any movement or sign of uneasiness. 
There was total insensibility to mere contact. The right hand and foot could be 
touched or gently rubbed without any sign of perception on the part of the animal: 
whereas the same on the left caused the animal to look and move away from the 
disturbance. 
There was no motor paralysis. All the limbs were freely moved. But the animal 
for purposes of prehension used the left hand almost exclusively. Hearing to the right 
was undoubtedly retained. Further observations an hour later showed that vision 
MDCCCLX XXIV. 4 B 
