ON THE FUNCTIONS OF THE CEREBRAL CORTEX. 
31 
lesion, and sufficient to account for the fact that the paralysis extended to the parts 
with which the convolutions in question are connected. 
This animal also lived one week only. 
The superficial extent of the lesion is represented in fig. 17, Plate 2. 
18. 
Lesioii 1. — Excision of the posterior three-fourths of the left marginal gyrus. A 
small part of the lower edge of the convolution was, however, left, as the section of 
the brain shows (fig. 18a). 
Res^ilt.' — Partial paralysis of right leg, especially the extensors of the hip and the 
flexors of the knee. No determinable paralysis of trunk. 
Lesion 2. — Second operation, twenty-one days later. In this operation most of 
the external motor areas were removed, including the anterior slope of the ascending 
parietal, the whole of the ascending frontal as far as the lower end of the fissure of 
Rolando, the posterior third of the superior frontal gyrus, and the part of the middle 
frontal gyrus included in the angle of the prefrontal sulcus. All this part of the brain 
was perfectly healthy when exposed for removal. 
Result. — There is paralysis with contracture of both right limbs, but the hemiplegia 
and prostration are not so complete as in the cases previously recorded, which is no 
doubt due to the fact that the lesion was not quite so extensive. There is some 
slight ability to grasp with the fingers of the right hand, but Jione with the toes of 
the corresponding foot. There is distinct contracture at right elbow, hip, and knee ; 
when actively climbing, the right arm and hand are occasionally employed, but not the 
corresponding leg. No difference of sensibility can be determined upon the two sides. 
The knee-jerk is normal (These notes were made two months after the second 
operation.) This Monkey was kept nearly four months after the second operation. 
The brain is represented from above in fig. 18, and in frontal section in fig. 18a. 
The section passes through the widest part of the lesion. 
19. 
Lesion. — Excision of both marginal convolutions (on the left side for the posterior 
three-fourths of the longitudinal extent, on the right side slightly less). The lesion, 
as shown by examination of the brain after death, does not quite reach either the 
upper or lower margin of the convolution, especially on the right side. It was followed 
by considerable shock. 
Result. — Almost complete paralysis of trunk and leg muscles, but there is some 
ability to move, especially to flex, the legs, particularly the left leg. When placed 
upon the floor, the animal seizes neighbouring objects and pulls itself up into 
sitting posture by arms ; sits propped up on both arms with feet splayed out and 
knees in ; appears unable to extend the spine or to move the tail, but head can be 
flexed, extended, and rotated. 
