(10) Complexion deep brown or blackish, and in some cases even distinctly black, due not to any special pigment, as is often supposed, but merely to the greater abundance of the coloring matter in the Malphigian mucous membrane between the inner or true skin and the epidermis or scarf skin. (11) Short, black hair, eccentrically elliptical or almost flat in section, and distinctly woolly, not merely frizzly, as Prichard supposed on insufficient evidence. (12) Thick epidermis, cool, soft, and velvety to the touch, mostly hairless, and emitting a peculiar rancid odor, compared by Pruner Bey to that of the buck goat.[11] [11] This misfortune should, of itself, be sufficient to settle the question of social intercourse. The emanation is from certain overabundant sudorific glands. (13) Frame of medium height, thrown somewhat out of the perpendicular by the shape of the pelvis, the spine, the backward projection of the head, and the whole anatomical structure. (14) The cranial sutures, which close much earlier in the Negro than in the other races. To this premature ossification of the skull, preventing all further development of the brain, many pathologists have attributed the inherent mental inferiority of the blacks, an inferiority which is even more marked than their physical differences. Nearly all observers admit that the Negro child is on the whole quite as intelligent as those of other human varieties, but that on arriving at puberty all further progress seems to be arrested. No one has more carefully studied this point than Filippo Manetta, who, during a long residence on the plantations of the Southern States of America noted that 'the Negro children were sharp, intelligent, and full of vivacity, but on approaching the adult period a gradual change set in. The intellect seemed to become clouded, animation giving place to a sort of lethargy, briskness yielding to indolence. We necessarily suppose that the development of the Negro and White proceeds on different lines. While with the latter the volume of the brain grows with the expansion of the brain-pan, in the former the growth of the brain is on the contrary arrested by the premature closing of the cranial sutures and lateral pressure of the frontal bone.'" (_La Razza Negra nel suo stato selvaggio e nella sua duplice condizione di emancipata e di schiava_, Torino, 1864, p. 20).