ON THE BRAINS OF TWO IDIOTS OF EUROPEAN DESCENT. 
515 
radiating convolutions on both sides, but on the right side these appear larger than on 
the left. In the European brain these radiating convolutions again subdivide along 
their upper and outer borders, so as to appear still more numerous. 
The hinder end of the supramarginal convolution expands, as usual, into its so-called 
“ lobule ” (Plates XVII. & XVIII. figs. 1 & 3, a-a), which is described by Gratiolet 
as a part peculiar to Man — a statement undoubtedly true if the lobule be regarded 
merely as an expanded or highly developed portion of the supramarginal convolution 
itself, but not to be accepted as implying that the lobule is an entirely new part of the 
cerebrum, wholly unrepresented in the quadrumanous brain. Even as regarded in the 
former light, the condition of this lobule of the supramarginal convolution in the Bush- 
woman’s brain is of special interest. It protrudes in her brain in the form of a large 
nearly quadrangular mass, situated exactly beneath the parietal eminence of the skull, 
and corresponding therefore with the line of greatest width of the cerebrum ; it overhangs 
the upper part of the Sylvian fissure ; it is connected in front, by a partially concealed 
convolution (#) already mentioned, with the posterior ascending convolution, above 
with the lobule of that convolution, and behind with the bent convolution ( 6 ) ; and 
it is marked by several secondary sulci. In all these particulars it resembles the part in 
the European brain, but it is somewhat smaller. On the other hand, it is decidedly 
superior to that of the Hottentot- Venus brain, being larger and more complex, pro- 
jecting more over the Sylvian fissure, and having a more superficial connexion with the 
posterior ascending convolution. Relatively it is one of the most developed parts of the 
Bushwoman’s brain. 
The bent convolution (6-6) (pli courbe, Gr.), which limits the summit of the Sylvian 
fissure, is connected in front with the lobule of the supramarginal convolution, and, 
turning downwards, sinks in between the upper external temporal (Plate XVIII. fig. 3 , 7 ) 
and middle temporal (s) convolutions, on the left side, as is usual; whilst on the right 
it continues superficial, but does not join the superior temporal convolution as in the 
Hottentot-Venus brain; in the latter brain it is a simple though somewhat tortuous 
convolution, whilst in the European brain it is represented by two or more convolutional 
folds. It is decidedly defectively developed in the Bushwoman’s brain. 
The three rows of external temporal convolutions (Plates XVII. XVIII. & XIX. figs. 2, 
3, & 5) are intermediate in character between the European and Hottentot condition. On 
the left side they are more complex than on the right, where they resemble more nearly 
those of the Hottentot Venus. The upper temporal, or inframarginal convolution (7-7) 
| (pli temporal superieur, Gr. ; antero-temporal, H.) is bent, and somewhat constricted, 
opposite the ends of the ascending parietal convolutions, at the peculiar horizontal step 
of the Sylvian fissure. It is separated from the bent convolution, as usual, by a secondary 
sulcus. As in the Hottentot Venus, it is proportionally wider than in the European 
brain. The middle temporal convolution (s-s) (pli temporal moyen, Gr., medio-tem- 
poral, H.) is narrower, more tortuous, and slightly more complex than in the Hottentot 
brain, but not nearly so wide or so much intersected with secondary sulci as in the 
