49G 
PROFESSORS D. FERRIER AND G. F. YEO ON THE EFFECTS OF 
Half an hour later several similar tests were made. A piece of apple was thrown 
near it. This it took, and began to eat. On the piece being taken from it, it seized 
another piece lying in the cage and ate this, and having finished it, came forward a 
few steps and picked up another piece lying on the floor. 
There was thus the most complete proof of retention of vision. Hearing was acute ; 
cutaneous sensibility was unimpaired, the slightest touch anywhere on its bodv 
exciting its attention. It smelt the apple before eating, and evidently enjoyed the 
taste. 
Next day the animal seemed in the most excellent health. Took things offered it 
with the utmost precision, and picked articles of food from the floor. It came out of 
its cage when the door was open, and had a look at its companions, and playfully 
tickled the ear of a kitten which came past its cage. 
From this time onwards it continued in perfect health, and without the slightest 
discoverable impairment of vision or other deficiency. 
Nearly six weeks after the first operation the left angular gyrus was exposed, and 
this and the anterior portion of the remainder of the occipital lobe cauterised with 
the galvanic cautery. The left eye was securely closed. 
Half an hour after the operation the animal was sitting up, on the alert, and 
listening to the grunts of its companions. When touched it started, and bounced 
with its head full against the leg of the observer. 
An hour after the operation it seemed to have some obscure power of vision, but in 
running along the top of the hot-water pipes, it knocked its head against the brackets, 
now on the right and now on the left. Made a vague sort of motion towards a piece 
of bread held in front of it, but did not reach it. 
Constant observation for another hour was made with a view to determine whether 
it saw to one side or the other better, but without settling the point. It seemed to 
see better to the left than to the right, and yet on one occasion it turned to the right 
and took a piece of biscuit with its right hand. 
Two hours and a half after the operation it was able to see so well to the left as to 
be able to pick up grains of oats scattered on the floor towards its left side, and with 
its left hand. But it took some with the right hand, though not quite precisely, from 
a heap of grains held in the palm of the hand towards its right. 
Next day, twenty-four hours after the operation, constant observation and various 
tests were made for two hours in respect to the question of vision to the left and 
right. There was no doubt that though it saw to the left, it also did so to the right. 
It picked up grains preferably to the left, and with the left hand, but on several 
occasions it picked up currants, &c., to the right with its right hand. On one occa¬ 
sion it was sitting with the left side close against the wall, but it reached its right 
hand well to the right side to pick up grains, &c., lying on the floor. Threatened 
towards the right side it started and ran away. Vision to the right seemed therefore 
fully established. 
