548 
PROFESSORS D. FERRIER AND G. F. YEO ON THE EFFECTS OF 
the region of the pulvinar and corpora geniculata, everything is gone below the 
middle temporo-sphenoidal convolution, a portion which also is gone. Fig. 130 is a 
section somewhat further forwards showing essentially the same condition ; while 
figs. 131 and 132, in the region of the lenticular nucleus, show the similar complete 
removal of the hippocampal and inferior temporo-sphenoidal region, everything else 
being absolutely intact. 
Remarks .—■ The destruction of the hippocampal region in the manner carried out in 
this experiment involves many risks and is purely a matter of calculation founded on 
anatomical measurements of the probable depth of the parts which it is desired to 
reach, as they cannot be exposed to view. 
From an operative point of view the experiment left little to be desired, but un¬ 
fortunately when all seemed to be going well it was cut short, apparently by secondary 
haemorrhage from the injured surface. Hence was lost an opportunity of determining 
the permanency of the condition of total hemianalgesia and hemiansesthesia so well 
manifested in this case. In addition to the insensibility to pain and contact, 
cutaneous and mucous, the condition of the limbs indicated loss of the so-called 
muscular sense. There was no motor paralysis—every volitional movement being- 
capable of being carried out. But the awkward manner in which the animal planted 
its limbs, and slipped and fell repeatedly on the right side, especially when its atten¬ 
tion was withdrawn, is typical of the condition termed loss of the muscular sense. 
Hearing was absolutely unimpaired on the right side, and it is seen that there was 
no lesion of the superior temporo-sphenoidal convolution. 
The only abnormality besides loss of tactile and muscular sensibility on the right 
side was slight impairment of vision towards the right—a condition readily explicable 
by the lesion of the cortex and medullary fibres of the occipito-angular region. 
The total absence of lesion in the crus, central ganglia and internal capsule, and 
the accurate limitation of the lesion to the hippocampal and lower temporo-sphenoidal 
region, proves conclusively that in this region are situated the centres of tactile and 
muscular sensation. 
Experiment 28 (Plate 31, figs. 133-140). 
In this case, as in Experiment 27, the left hemisphere was exposed in the region of 
the junction of the temporo-sphenoidal with the occipital lobe, and at this point a 
horizontal incision was made with a wire cautery guided by a director, and another 
along the second temporo-sphenoidal fissure with a view to separate and detach the 
inferior temporo-sphenoidal convolution and hippocampus, as in the last experiment. 
The operation was effected with little haemorrhage, and the animal in the course of 
an hour was able to make efforts to sit up, moving all four limbs, but always falling 
over on the right side as soon as it gained the upright position. 
At this time, and for two hours after the operation, frequent observations showed 
