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PROFESSORS D. FERRIER AND G. F.'TEO ON THE EFFECTS OF 
At the anterior extremity of this groove the track of the cautery became lost to 
sight, it having penetrated the lower extremity of the temporo-sphenoidal lobe external 
to the anterior extremity of the gyrus hippocampi. 
At this point there was some adhesion of the cortex to the dura mater, and some 
damage was done to the brain in separating it. 
The brain was hardened in bichromate of ammonia, and owing to too long immersion 
was so brittle that the sections frequently broke. It was cut parallel to the fissure of 
Rolando, but the plane of section was not quite transverse, sloping more towards the 
left. This explains the obliquity presented by the sections on Plate 29, figs. 1 li¬ 
lt G, arranged from before backwards. Owing also to the anti-actinic colour of 
the sections the prints are rather indistinct in details of structure. 
The sections show that on the right side (on the observer’s right) the cautery had, 
after penetrating the medullary fibres of the occipital lobe, struck into the descending 
cornu of the lateral ventricle. The posterior extremity of the hippocampus was almost 
detached by division of the medullary fibres (fig. 116). Fig. 115 shows a point where 
the cautery penetrated the hippocampus. More anteriorly the cautery left the hippo¬ 
campus itself and emerged gradually, dividing some of the medullary fibres of the 
hippocampal region. 
In figs. Ill and 112 there is some rupture of the fibres of the internal capsule, due 
to the brittleness of the sections and injury in mounting. 
The corpora quadrigemina, crura, pulvinar and optic tract are altogether free from 
lesion on this side. 
In the left hemisphere the lesion is more extensive. 
Fig 116 shows the region of the posterior cornu and base of the hippocampus 
almost entirely broken up, and a similar condition is seen in fig. 115. 
Figs. 114 and 113 show where the cautery struck and carried away the optic tract 
and corpus geniculatum externum, while the corpus geniculatum internum and 
pulvinar of the optic thalamus are uninjured. 
The cornu ammonis in this region has been extensively injured and portions of the 
gyrus hippocampi have also been destroyed, though the outer half of this gyrus was 
not originally in the track of lesion, though somewhat incomplete in the sections 
owing to their having broken off. 
Further forwards the cautery penetrated the under surface of the lenticular nucleus 
and divided the fibres of the external capsule, and so injured the inferior temporo- 
sphenoidal region that the sections could be with difficulty kept with all the parts in 
situ. The anterior extremity of the cornu ammonis was considerably injured, though 
not entirely destroyed. The medullary fibres of the superior temporo-sphenoidal con¬ 
volution were seen to be ruptured in many of the sections (fig. 112), but in others 
(fig. Ill) they were not, or only partially, divided. 
Remarks .—This experiment is recorded as possessing some features of importance, 
