482 
PROFESSORS D. FERRIER AND G. F. YEO ON THE EFFECTS OF 
Sis months after the operation on the occipital lobes, the prefrontal regions were 
similarly exposed and broken up with the galvanic cautery—the lesions being made, 
so far as could be determined, in the region of the middle frontal convolution anterior 
to the antero-parietal or pre-central sulcus. 
In less than an hour the animal began to move about, though in a somewhat 
sleepy and listless manner. 
An hoar and a half after the operation it was able to walk about quite well, and 
took a piece of apple offered it. Left to itself it shut its eyes and seemed asleep, but 
if called to it opened its eyes momentarily, but subsided again. 
An hour subsequently it still maintained the same dull and listless attitude, though 
when called to it would brighten up for a moment. It jumped down eagerly to seize 
a piece of apple thrown into its cage, but having got it, remounted its perch and went 
to sleep holding the apple in its hand. 
Next day the condition was much the same. The animal would wander about 
vacantly, or occupy itself picking among the rubbish in its cage. 
Watched from day to day, it exhibited no defect as regards any of its movements, 
ocular or otherwise, or as regards any of its sensory faculties, which were tested in 
various ways. Only its manner seemed changed, and this was noted by all who had 
seen its former vivacity. It lost all its fun and trickiness, seemed not to know 
its name, took little or no interest in its companions, and was very easily cowed by 
them. Its physical health was excellent, and it enjoyed its food heartily. Psychically 
only it had undergone appreciable change and degradation. 
In this condition it continued for the next three months, when it was killed with 
chloroform. 
Post-mortem examination .—The brain was everywhere normal, except in the pre¬ 
frontal and occipital regions corresponding to the openings in the cranium above 
described. These -were covered by membrane continuous with the dura mater and 
adherent to the brain beneath. 
The occipital lobes were each the seat of a depression and loss of substance, the 
cicatrices of the destructive lesions inflicted on them (see Plate 20, fig. 2). These 
were almost symmetrical and occupied the convexity of each occipital lobe about a 
centimetre in extent and depth, parallel, and ^ inch posterior to the parieto-occipital 
fissure. 
In each prefrontal lobe there was a more or less circular cicatrix, somewhat larger 
on the right than left, and measuring '5 — - 75 centimetre in diameter, the centre of 
which appeared to correspond with the middle of the middle frontal convolution. 
But there was an evident distortion of the convolutions which seemed to be caused 
by a contraction towards the centre of the cicatrices, and this to such an extent as to 
tilt the orbital surface upwards and forwards. This condition is seen in the photo¬ 
graph, where the slight shadow indicates the orbital aspect of the frontal lobes. The 
cicatrices, which sunk to a depth of half a centimetre or more (Plate 20, fig. 2), measured 
