DR. D. FERRIER ON THE BRAIN OF MONKEYS. 
453 
On this being done, sounds which formerly caused the animal to prick its ear and look 
round, failed to cause any reaction or excite its attention. 
Sounds made by concussion caused the animal to look round, as well as the making 
of any sound which likewise attracted its attention by sight. 
Whether, therefore, the animal heard or not, it gave no sign of such sensations being 
aroused. 
It was also found that reaction to pricking and pinching was considerably less on the 
right than on the left side, though not completely abolished. 
The animal died next day in a comatose con- K 
dition. 
Post mortem Examination . — The injury to the 
brain involved the convolutions to the extent 
described. 
The division was carried down to the hippo- 
campus, which, however, was not severed ; and the 
lower part of the uncinate convolution and of the 
temporo-sphenoidal convolutions still remained, 
^though almost severed from the rest of the 
temporo-sphenoidal lobe. 
This experiment only gave partial indications 
of impairment of certain senses, particularly of 
hearing and smell, and in some degree of tactile 
sensation, and is chiefly important in relation to 
the other experiments to be described. 
Fig. 13 represents the left hemisphere, and 
the shaded part indicates the seat of lesion in 
Experiment XI. The deep shading in the 
centre is intended to represent the part at which 
the temporo-sphenoidal lobe was deeply divided 
transversely almost as far as the hippocampus 
major. The lighter shading represents the 
extent to which the surface of the convolutions 
was destroyed. 
Experiment XII. 
January 27th, 1875. — The left hemisphere of a lively and intelligent monkey was 
exposed by a trephine opening in the region of the annectent gyrus connecting the 
posterior limb of the angular gyrus with the occipital lobe, and the upper part of the 
superior and middle temporo-sphenoidal convolutions further exposed by the bone- 
forceps. 
With the cautery the convolutions exposed were thoroughly cauterized and the grey 
matter destroyed scooped out, while the cautery was directed horizontally inwards, so as 
to divide the lobe transversely as far as possible, taking care to avoid sinking it so deeply 
as to injure the crus. (See fig. 14, where the darkest part of the shading indicates the 
region of the greatest depth.) 
The operation was completed at 4 p.m. 
After a few minutes the animal recovered from its stupor, and began to look around. 
Endeavoured to get up, but staggered towards the right side. Gradually recovered 
its equilibrium. 
