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PROFESSORS D. FERRIER AND G. F. YEO ON THE EFFECTS OF 
the convex aspect of the superior frontal convolution. The tip of this had been almost 
entirely severed by a transverse incision, which did not however extend to the orbital 
aspect. The mesial aspect of this convolution was also uninjured. The cortex was 
also deeply eroded, but not entirely removed, over the whole extent of the middle 
frontal convolution, except at the base; and the inferior frontal convolution was 
also almost entirely destroyed, the base remaining uninjured. 
On the right side the middle frontal convolution was almost entirely destroyed, 
a small portion of the base immediately adjoining the precentral sulcus still remaining. 
Though the superior frontal convolution still retained the cortex for a breadth of a 
quarter of an inch external to the longitudinal fissure, yet it was undermined by 
severance of the medullary fibres almost close up to the longitudinal fissure. 
The base of the inferior frontal convolution was uninjured, but the rest was entirely 
destroyed. 
The orbital aspect, with the olfactory tracts and bulbs, was free from lesion, though 
the orbito-frontal margin was ragged and eroded. 
Remarks .—This case was also unsuccessful as regards long duration of observation, 
but it is instructive as showing that destruction of the greater portion of the cortex of 
the frontal lobes anterior to the precentral sulci, though at first causing great impair¬ 
ment of the movements of the head and eyes, particularly in a lateral direction, does 
not permanently render these impossible. For already on the second day after the 
operation, movements of the head and eyes to either side were seen without any 
appearance of stiffness or turning of the trunk. The lesions, however, did not impli¬ 
cate the whole of the regions irritation of which causes lateral movements of the head 
and eyes. 
There was no defect of motor power other than of the head and eyes immediately 
after, or at any time subsequent to the lesion; and common and special sensibility 
were unimpaired. The curious purposeless restlessness before observed was also very 
evident in this case, alternating with general dulness and apathy. 
Experiment 21 (Plate 25, figs. 58, 59). 
In this animal—a large dog-faced Monkey—the frontal regions were exposed in both 
hemispheres, and severed by the galvanic cautery by a transverse incision just anterior 
to the precentral sulcus. Both frontal lobes were removed bodily. 
An hour after the operation the animal lay with its eyes shut, but partially opened 
them when disturbed, and made spontaneous sprawling movements with all four limbs. 
Sensibility was evidently retained all over the body, as it moved or grunted if slightly 
pinched anywhere. 
Ammonia held before its nostrils caused it to snort or sneeze. 
An hour after the operation it would start at sounds, opening its eyes feebly, 
and also if touched anywhere on the trunk or limbs. The right arm and leg did 
