Page:Popular Science Monthly Volume 46.djvu/544

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her exact capacity. The Malay, although much higher in intelligence, has a still less cranial capacity, being only from fifty-seven to sixty-two, thus showing at the largest but one cubic inch in excess of that of the Bushwoman, and at the lowest, four cubic inches below hers. The Hottentots, but a shade if any higher in intelligence, have the large comparative average of seventy-five, or fourteen cubic inches more than the Bushwoman; while the Hindu, with all his arts and sciences, his literature, castes, complex government, and great book religions dating back to the very dawn of the historic period, has a less cranial capacity than the Malay, the negro, or the Hottentot, and it has been found in some normal instances as low as forty-six cubic inches. Is it not clear, then, that cranial capacity alone is not an infallible index of mental capacity or intelligence?

But Mr. Marshall found other and more important conditions in which the Bushwoman was exceedingly low down, notwithstanding her comparatively ample cranial capacity.

Let us quote his own words: "The convolutions are remarkably simple. The extreme curved convolution forming the outer border of the frontal lobe consists of three short, simple, curved branches, very like those found in the ape, instead of the tortuous sulci seen in the European brain. The forms of the surrounding orbital convolutions themselves, including the supra-orbital, are so broad and simple that the subordinate divisions which are so complex in the European brain can hardly be said to exist. All four of the primary convolutions are present, but all are characteristically short, narrow, and simple, instead of being complex and occupying a large space, but the arrangement is normal. They are evidences of structural inferiority, and show an infantile or even fœtal leaning." Having regard to the sum of its convolutional characters, judged by their presence or absence, their individual and relative size and position, their comparative simplicity or complexity, and the symmetry or asymmetry of particular fissures and convolutions, there is after all, Mr. Marshall concludes, a greater difference between the Bushwoman's brain and that of the highest apes yet described than between it and the European brain, but not so great a difference as exists between the brain of the orang and that of the chimpanzee, or between the brains of many other species of quadrumana.

Here we have two very interesting and important facts disclosed, which have been substantiated by many other similar investigations, of which this recital is but an example. First, that cranial capacity is not the main factor in determining intellectual and emotional development, but that increased brain surface, or the extent, number, variety, and depth of convolutions by