530 
PROFESSORS D. FERRIER AND G. F. YEO ON THE EFFECTS OF 
aspect of this convolution, all along the longitudinal fissure ; but at the anterior 
extremity it became distorted towards the left side. 
The base of the inferior frontal convolution also remained; but the middle frontal 
was obliterated, its place being indicated by a surface sloping obliquely downwards 
and forwards from the precentral sulcus to the centre of the triradiate sulcus in the 
orbital aspect of the hemisphere. The anterior two-thirds of the inferior frontal 
convolution were also entirely removed. 
There was thus lesion, without entire destruction, of the posterior third of the 
three frontal convolutions, with complete removal of the anterior two-thirds of the 
inferior and middle, and portions of the superior frontal convolutions, on the left 
side ; and complete removal of the middle frontal, and anterior two-thirds of the 
inferior frontal convolution on the right side. 
Microscopical examination .-—A series of sections was made of the brain (hardened 
in bichromate of ammonia) from before backwards parallel to the fissure of 
Rolando, or at right angles to the crura; and also transverse sections of the pons 
and medulla. (A series of sun-prints of these arranged from before backwards is 
given in Plate 27, figs. 75-86.) 
At the lower internal margin of the crescentic-shaped section of the internal 
capsule, precisely corresponding to the position of the sclerosed patches in Experi¬ 
ment 22, specially well seen in figs. 76 and 77, some of the bundles were deeply 
stained, and therefore appear light in the prints, while others internal to these were 
less stained than the normal, and therefore appear as dark patches in the prints. 
In the sections of the crura (figs. 7.9-82) the median or most internal bundles of the 
foot of the crus were most deeply stained, and in some of the sections there w^as an 
appearance as if some of these bundles took a direction upwards towards the region 
of the aqueduct of Sylvius (figs. 79 and 81). 
In sections of the upper part of the pons some bundles were seen more deeply 
stained than the others. They occupied the same relative position to the rest of the 
fibres of the pyramidal tracts as in the crus and internal capsule, viz., the mesial 
aspect. But these deeply-stained bundles could not be traced beyond the pons, and 
could not be seen in the sections of the medulla oblongata (figs. 83-86). 
Remarks .-—In this experiment there occurred at the moment of cauterisation of 
the base of the superior and middle frontal convolutions, a conjugate deviation of 
the eyes to the same side. This was also observed in another case, not here reported 
in detail owing to the animal having died soon after the operation without having 
regained consciousness. 
But notwithstanding the extensive lesions at the base of both frontal lobes, no 
physiological defect, either sensory or motor, persisting the day after the operation, 
was at all appreciable. Whether at this time the movements of the head and eyes 
were deficient was not clear, but on the third day it was plain that these were capable 
of being effected to all appearance in a perfectly normal manner. 
