The following seems to have been written with some foreboding of the more recent anthropology that "minimizes this difference" between European and Negroid, and regards "the mental gap as more apparent than real, and due rather to experience and training than to innate factors." "The capacity for spiritual achievement is, I believe, as regards both magnitude and variety, always innate, a gift of Nature, and expressed in the magnitude and weight of the brain and the development of the convolutions, either in the whole or in the single parts. In it, aside from morbid alterations, the individual can bring about no change, neither by addition nor by subtraction. But the degree and the kind of the development of this endowment (_Ausbildung dieser Anlage_) depends on a thousand other conditions, partly quite beyond the insight and will of the individual--partly, however, subject thereto. All that we call education, culture, social position, example, and, on the part of the individual, good-will, industry, zeal, etc., work for the development of the endowment, and the achievement depends thereon. Endowment, as already said, is unalterable; but the degree of the development and achievement may vary a thousandfold" (p. 165). On p. 169, Bischoff starts the interesting query, whether any enhancement of the endowment (_Steigerung der Anlage_) in general or in particular directions, through increase of the brain, in general or in particular parts, be actual or possible in the course of time, along the path of culture (_auf dem Wege der Zuchtung_). Broca thought that he had observed a change in the skull capacity of Parisians, in the lapse of centuries; but his results (thinks Bischoff) are very far from being sure. Thus far there is no proof of any such possibility. But even if this latter were conceded, Bischoff adds, the actuality of such a change would by no means follow. So great is the present endowment that all progress that can thus far be proved, may be explained through the development of this endowment, and such will, doubtless, for a long time yet, be the case as regards both the individual and the generations (p. 170). We may add that Bischoff has no doubt whatever either of the lesser brain-weight or of the lower mental capacity of the African Negro. When, now, we ask what is the real significance of these weights, we are fortunately able to refer to the tables of Dr. H. Matiegka, given in Part I. of his researches "_Ueber das Hirngewicht, die Schädelkapacität und die Kopfform, sowie deren Beziehungen zur psychischen Thätigkeit des Menschen_" (_Sitzb. d. kön. böhm. Ges. d. Wiss. 1902_). He has arranged 235 brain-weights in six groups, according to occupation, proceeding from the lowest labourers at odd jobs, who could not learn a trade or find steady employment, up to men of notable intellectual power. Here is the table, showing the number in each group and the average weight of brain: