498 
PROFESSORS D. FERRIER AXD G. F. YEO OY THE EFFECTS OF 
this case there was considerable hernia cerebri, and the angular gyrus of the right side 
was involved in the lesion. 
As the brain of this animal had been carefully preserved in spirit since 187o, photo¬ 
graphs were taken and are here appended (Plate 21, figs. 18 and 19), so that the 
condition of the brain may be accurately seen. 
Experiment 10* (Plate 21, fig. 17). 
In this animal the left angular gyrus and anterior half of the occipital lobe were 
exposed, and thoroughly cauterised, and the rest of the occipital lobe severed and 
removed. 
The portion removed weighed 2’55 grammes. 
The left eye was securely closed. 
The right eye was open, the pupil contractile to light, and the conjunctival reflex 
distinct. 
When the animal began to move about half an hour after the operation it was 
totally blind, paying no attention to threats, though excessively timid, and knocking 
its head against obstacles in its path. 
An hour after the operation there were some indications of vision, and observations 
were continued for an hour and a half after this with a view to determine the exact 
extent, and whether vision was unilateral or not. For a lone- time it remained 
doubtful, but it seemed as if vision was abolished towards the right side at least. 
Next day blindness towards the right was distinctly proved, as the animal occasion¬ 
ally knocked its head on the right side. The left eye was then unclosed, and the 
right secured. 
Sight seemed improved, but the animal still, especially when hurried, knocked its 
head on the right side in its career. It was able to pick up things with its left hand 
towards the left. 
On the day following both eyes were allowed free. Defect or abolition of vision 
towards the right was still very apparent, as on several occasions the animal knocked 
the right side of its head against the legs of chairs, tables, &c., in its wanderings. To 
the left it could see, and take hold of things offered it. 
On the fourth day after the operation the animal was able to run about, evidently 
with improved vision, for it did not now knock its head though passing and repassing 
obstacles on every side. It was observed to pick up grains of oats scattered on the 
floor, with its left hand. 
And at dusk, as it was being pursued into its cage, it knocked its head on the right 
side, in a dark corner of the laboratory. 
On the fifth day it ran about very freely never knocking its head. On this day, in 
addition to picking up things readily with its left hand, it was seen to turn to the 
right and pick up a piece of apple, thrown down, with its right hand. On the sixth 
