ON THE BEAINS OE TWO IDIOTS OE EUROPEAN DESCENT. 
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being, on the part of the idiot’s brain, a slightly more elevated and broader frontal 
region ; a shorter beak-like process ; less excavated orbital surfaces, so that the angle 
formed by their meeting-point in the middle line is more obtuse ; and larger, less in- 
curved, and more widely separated temporal lobes. On the posterior aspect ( d , d') the 
casts, on the other hand, are very different, — the cerebrum of the idiot being of less width 
in the parietal region ; attenuated in length, width, and depth in the occipital region ; 
and having the cerebellum projecting at each side, and so large as to appear to tilt the 
cerebrum upwards, and to occupy in this aspect an area equal to one-third of the whole 
encephalon ; whilst in the Ape the cerebellum is overhung by the cerebrum, and forms 
a mass not more than one-fourth of the visible part of the encephalon. Seen on the base 
( e , e'), the oval shape of the entire mass, the greater width and flatness of the frontal 
lobes, the size of and width between the temporal lobes, and the complete concealment 
of the posterior lobes of the brain by the voluminous cerebellum, distinguish the idiot’s 
from the Ape’s brain. 
The preceding description, and the tabulated measurements of the brains, given at 
the end of this paper, show that in the idiot woman the temporal regions manifest the 
greatest relative size, whilst the parietal, occipital, and frontal are very small ; whereas 
in the Chimpanzee’s cerebrum the occipital lobes have a larger relative development ; 
the frontal lobes stand next, whilst the temporo-parietal are defective. 
The cerebrum of the idiot boy, as seen from above, the only view of which we have 
an intracranial cast, differs from that of the idiot woman in being at once narrower and 
somewhat angular in its outlines. The frontal region is more pointed (indeed, singu- 
larly so), the occipital region flatter, and the parietal regions longer and more com- 
pressed. The widest part corresponds with the centres of the parietal regions, and is 
somewhat behind the middle of the mass. The ratio between the width and length of 
the cerebrum is 1 to T23; so that the idiot boy’s cerebrum is longer, in proportion to 
its width, than the idiot woman’s — not from any actual superiority as to length, but 
rather owing to a deficiency in width of the whole cerebrum. As in the idiot woman, 
the cerebellum is not covered by the cerebrum behind ; but probably it was not so much 
exposed. In shape the idiot boy’s brain is so long and narrow as not to be comparable 
with the Ape’s. 
In the idiot woman the forms of the convolutions are scarcely traceable at any part 
of the intracranial cast, excepting some slight undulations about the frontal region. In 
the idiot boy they are remarkably distinct on the parietal regions, whilst the frontal and 
occipital regions are perfectly smooth. Gratiolet regards this marking of the cra- 
nium by the convolutions as a sign of inferiority or degradation. This would appear 
to be, to a certain extent, an individual character, as it is not noticeable in the idiot 
woman. 
