LESION OE DIFFERENT REGIONS OF THE CEREBRAL HEMISPHERES. 489 
Slight pinching of its fingers and toes on the right excited precisely the same 
indications of attention and uneasiness as on the left. 
Five days after the last observations the same condition was seen. Experiments 
were made, consisting in suspending the animal by the hand or foot. When this was 
done with the left hand or foot, the animal speedily got its mouth up conveniently to 
give a bite, but quite failed to grip and pull its body up to do the same, when 
suspended by the right. But on one occasion, when held by the right hand, and 
failing to raise its head to bite, it skilfully laid hold of its right arm with the left, 
pulled its body up, and so nearly effected its purpose. 
Walking was with the same limp as before. 
At the end of four months the weakness of grip of the right hand and foot was 
still distinctly perceptible. 
Seven months after the operation the animal seemed somewhat paraplegic. The 
cause of this was doubtful, but it was probably the result of a heavy tray having 
fallen on its back some time before. 
An examination of the right hand indicated some degree of rigidity of the flexors, 
and forcible passive extension of the wrist and fingers seemed to cause uneasiness and 
spasm of the muscles of the upper arm and shoulder. 
The animal was found dead one morning by the laboratory attendant, exactly ten 
months after the first operation. 
Post-mortem examination .—The brain was somewhat soft, not having been removed 
for many hours after death, and was injured slightly during removal and separation 
of the membranes adherent over the seat of lesion. 
On the right hemisphere the angular gyrus had its limbs and sulci almost 
obliterated, but the grey matter at the bottom of the sulci was intact. The surface 
of the occipital lobe was somewhat ragged and soft for some distance behind the 
parieto-oceipital fissure, the results of post-mortem injury. 
The upper extremity of the arch formed by the two limbs of the angular gyrus 
was still more or less distinct. 
On the left hemisphere the grey matter of the angular gyrus was also similarly 
destroyed superficially, as well as the greater portion of the convexity of the ascending 
parietal convolution, and a considerable portion of the postero-parietal lobule. But 
the grey matter of the intra-parietal sulcus was intact, as well as that of the parieto¬ 
occipital sulcus. 
There was also superficial erosion over a considerable portion of the occipital lobe, 
posterior to the parieto-oceipital sulcus, due to post-mortem injury, in removing the 
brain and separating the adherent membranes. 
Remarks .—This case shows the occurrence of total loss of vision, for several hours 
during which observation was maintained, in the eye opposite extensive destruction of 
the cortex of the angular gyrus. Next day this had disappeared. On subsequent 
similar destruction of the other angular gyrus, sight was evidently abolished coiu- 
MDCCCLXXXIV. 3 R 
