542 
PROFESSORS D. FERRIER AND G. F. TEO ON THE EFFECTS OF 
but it was not entirely abolished, and the animal did not knock its head against obstacles 
on the right side. The signs of sensation on the right side were, however, less 
vigorous than on the left. Hearing was apparently unimpaired on the right, as the 
animal turned its head equally sharply to sounds made close to its right ear as on 
the left side. 
Beyond the slight defect in tactile sensibility and vision towards the right, there 
seemed nothing abnormal. 
Next day the animal was in excellent health and vigour. No tactile anaesthesia 
could be discovered; hearing was acute on both sides ; and vision, though apparently 
defective, continued towards the right. 
Nothing else worthy of note was observed, and the animal continued well, with 
perhaps impaired vision towards the right, for three weeks, w T hen the right occipital 
lobe was exposed posteriorly, and a wire coated with perchloride of iron was pushed 
through the extremity of the occipital lobe downwards and forwards, approximately 
along the hippocampal region. 
When the animal had regained consciousness, immediately after the surgical dressing, 
a heated point applied to the left hand and foot caused scarcely any perceptible sign 
or reaction, wdiereas when it was afterwards applied to the right the most lively signs 
of sensation w r ere induced. 
Half an hour afterwards this was repeated with precisely the same result; and an 
hour after the operation a touch with a stick on the right side at once attracted the 
animal’s attention, but no sign of perception was seen when the same stimulus was 
applied to the left. 
Half an hour subsequently, a watch held near the ear caused twitching of the auricle 
on either side equally, and caused the animal to look round to the right and left 
accordingly. Hearing was thus seen to be retained on both sides. But the left 
auricle was touched and rubbed gently with the finger without causing the slightest 
appearance of consciousness, wdiereas the slightest touch on the right ear caused the 
animal to look and move away. 
Similar observations were repeated and the same indications of total loss of percep¬ 
tion of mere contact were obtained. The reaction to a heated point was not entirely 
abolished, but the signs of sensation were much less active than on the right. 
Next day various tests were applied in respect to tactile sensibility. There still, 
appeared total loss of sensation of mere contact, though painful stimuli v r ere felt to 
some extent. While the animal v 7 as resting quietly, ruffling the hair and tickling 
the skin with a long stick on the right side invariably caused the animal to scratch the 
part; but the same stimulus on the left side caused not the slightest sign of perception. 
When the point, instead of merely ruffling the hair, was pressed deeply, the animal 
seemed suddenly to be aw T areof something and moved away. This test was repeatedly 
performed with precisely the same result. A heated wire excited attention on the left 
side, but the signs of feeling were much less lively than on the right. Hearing was 
