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PROFESSORS I). FERRIER AND G. F. YEO ON THE EFFECTS OF 
killed with chloroform four months after the last operation, and over six months from 
the date of the first. 
Post-mortem examination .—The brain was everywhere normal, except in the regions 
where, as above described, the lesions had been made. Over these the dura mater was 
adherent, but elsewhere it was separable, and there were no indications of diffused 
inflammation. 
In the right hemisphere (Plate 20, fig. 5) the angular gyrus was obliterated except 
as regards a thin strip of cortical matter bounding the intraparietal sulcus, and at the 
upper extremity of the arch formed by the two limbs. The lesion extended posteriorly 
across the line of the parieto-occipital sulcus, undermining the anterior extremity of 
the occipital lobe. The edge of the uninjured cortex of this lobe was 4-5 mms. 
from the anterior extremity of the first occipital fissure. 
The superior extremities of the first and second temporo-sphenoidal convolutions 
merged gradually into the lesion. 
Horizontal sections through the lesions showed that the cortical matter of the 
convex aspect of both limbs of the angular gyrus had been completely removed, but 
that of the sulci separating them from the adjacent convolutions was intact. The 
grey matter at the bottom of the parieto-occipital sulcus, which is here folded deeply 
inwards, was also intact. That of the superficial aspect of the margins of this sulcus 
was destroyed. 
In the left hemisphere the amount of destruction of the grey matter was almost 
exactly the same as in the right; but the limbs of the angular gyrus were more com¬ 
pletely obliterated, and the lesion extended somewhat farther back into the convex 
aspect of the occipital lobe. 
The grey matter at the bottom of the sulci was not injured. 
Remarks .— This case is interesting both in its surgical aspects, showing how little 
effect even repeated operations on the brain may have on the well-being of the animal, 
and also from a physiological standpoint. 
There was for a short time after the animal was otherwise in full possession of all 
its faculties and powers, complete blindness in the eye opposite the injured angular 
gyrus. This gave way to such restoration of vision within two hours as to enable the 
animal to direct its actions without any appreciable deficiency. There was no hemiopia 
either immediately after the lesion or subsequently. 
The effects of destruction of the other angular gyrus, which however was less 
extensive than that of the first, was somewhat unexpected, as being unlike the usual 
results following injury to the one angular gyrus when the other is intact. 
At a time when any affection of the left eye was imperceptible, there was evident 
impairment of vision of an amblyopic not hemiopic character in the right eye, i.e., the 
same side as the second lesion. 
It would thus seem that the angular gyrus is in relation to both eyes, and that 
though usually the cross effect is the only pronounced one, yet the direct one may be 
