LESION OF DIFFERENT REGIONS OF THE CEREBRAL HEMISPHERES. 
527 
almost complete obliteration of the prefrontal lobes. Except a minute portion of the 
frontal extremities overlying the olfactory bulbs and the base of the superior and 
middle frontal convolutions (centre 12), all the intervening portion of the superior, 
middle, and inferior frontal convolutions had been destroyed, the destruction involving 
the orbito-frontal margin of the hemispheres as far as the central point of the 
triradiate fissure. 
Owing to the contraction caused by cicatrisation, the uninjured frontal apices came 
within a quarter of an inch of the anterior margin of the posterior third of the superior 
frontal convolutions which remained intact. For the same reason the orbital aspect 
of the hemispheres was tilted upwards and backwards to a considerable extent (fig. 60). 
Microscopical examination .—The brain after being sufficiently hardened in alcohol 
was cut in a series of frontal oblique sections, parallel to the direction of the* fissure of 
Rolando. They were stained with carmine, and sun-prints taken of sections at 
different levels from before backwards. They are seen on Plate 26, figs. 61 to 71. 
Figs. 72 and 73 are transverse sections of the medulla oblongata at the upper and 
middle of the pyramids respectively. 
Fig. 65 first shows clearly a condition, which is more obscure in the preceding 
sections, of sclerosis of the lowermost and innermost fibres of the crescentic shaped 
section of the internal capsule. The sclerosed parts being more deeply stained by 
carmine come out a lighter shade in the sun-prints. They are situated here on each 
side of the oblique section of the third ventricle. In fig. 66, which is essentially the 
same as fig. 65, the lighter sclerosed portions are seen in the same position. In fig. 67, 
behind the optic commissure, the patches occupying the same relative position are 
situated nearer the base. In fig. 68 they occupy the innermost part of the foot of the 
crus, and so in figs. 69 and 70 somewhat further back. 
Fig. 71 is a section just at the emergence of the crura from the anterior aspect of 
the pons, and owing to the obliquity of the section the anterior margin of the pons 
bridges over the space between the crura. The section does not show 7 so well as the 
former ones, being cut on somewhat a different plane and not so well stained. But at 
the innermost margin of the crus the sclerosis is still more or less apparent, being 
indicated by the white patches. The sclerosed patches were visible in all the sections 
as far as the crura cerebri, but they could not be traced beyond. Whether the bundles 
turned up into the corpora quadrigemina or became lost in the pons I have not been 
able to determine. 
But as Sections 72 and 73 show, there was no sclerosis visible in the anterior 
pyramids of the medulla oblongata. 
Remarks .—No cerebral lesion could wrnll have been more latent or devoid of 
symptoms, either physical or mental, than this. 
There was no discoverable sensory or motor defect, and no determinable pyschological 
alteration. Yet the prefrontal lobes on both sides were destroyed to a very great 
extent. But the bases of the three frontal convolutions, irritation of which reuion 
