556 
PROFESSORS D. FERRIER AND O. F. YEO ON THE EFFECTS OF 
Within two hours after the operation clear evidence was obtained of retention of 
hearing in the right ear. While it was sitting dozing, a slight whisper made near its 
right ear caused it to open its eyes and look round. No further observations were 
made this day, and next day the animal died suddenly before any further observations 
could be made. 
Pd.st-mortem examination .—On removal of the dressings there were signs of recent 
haemorrhagic extravasation at the orifice in the skull. On removal of the brain the 
left middle fossa was found filled with recent clot, some also having made its way to 
the anterior surface of the pons and medulla. 
There was no injury to the cranial nerves, crura, or cerebellum. On examination of 
the left hemisphere it was found that the posterior half of the middle temporo- 
sphenoidal convolution, the whole of the inferior temporo-sphenoidal convolution, and 
the gyrus hippocampi, except the inner margin, were broken up and destroyed. The 
region of the uncus was intact. The cornu ammonis itself, however, was still traceable 
among the debris at the bottom of the wound, and careful separation of the parts 
showed the fascia dentata, corpus fimbriatum, optic tracts, corpora geniculata, and 
corpora cpiadrigemina perfectly intact. This is well displayed in Plate 34, fig. 157, 
where all these parts have been exposed to view by merely pushing the hemispheres 
upwards and forwards, and drawing them asunder. 
Microscopical examination. — Frontal sections of the left hemisphere (Plate 34, 
figs. 158-163) showed that the occipito-temporal regions were so disorganised that 
they fell away from the rest on being cut, carrying the cornu ammonis and fimbria 
with them. At the anterior third of the gyrus hippocampi the lesion (fig. 162) did 
not entirely detach the gyrus hippocampi, and in the region of the nucleus amygdala? 
(fig. 163) a small hole indicates the termination of the lesion. 
Remarks .—In this case, in which again fatal secondary haemorrhage cut short the 
observations, the disorganisation of the inferior temporo-sphenoidal and hippocampal 
region was marked by the most profound anaesthesia of the opposite side of the body, 
both on the cutaneous and mucous surfaces. All the volitional movements were 
retained, but the manner in which the animal tended to fall over on the right side 
indicated the loss of the so-called muscular sense. 
Experiment 32 (Plate 35, figs. 164-172). 
In this case the posterior extremity of the left occipital lobe was exposed, and a 
director inserted between the under surface of this lobe and the tentorium cerebelli 
approximately in the direction of the gyrus hippocampi. A heated wire w r as then 
passed along the groove with the view of destroying this region. 
The animal soon recovered consciousness and began to make spontaneous movements. 
To various forms of stimuli, heat, &c., there was distinct reaction from the first, and 
further careful and repeated observations showed a remarkable degree of hyperaesthesia 
