We will now turn to the important subject of the size of the brain, which seems to be the one anatomical feature which bears directly upon the question at issue. It seems plausible that the greater the central nervous system, the higher the faculty of the race, and the greater its aptitude to mental achievements. Let us review the known facts. Two methods are open for ascertaining the size of the central nervous system,—the determination of the weight of the brain and that of the capacity of the cranial cavity. The first of these methods is the one which promises the most accurate results. Naturally, the number of Europeans whose brain-weights have been taken is much larger than that of individuals of other races. There are, however, sufficient data available to establish beyond a doubt the fact that the brain-weight of the whites is larger than that of most other races, particularly larger than that of the negroes. That of the white male is about 1360 grams. The investigations of cranial capacities are quite in accord with these results. According to Topinard, the capacity of the skull of males of the neolithic period in Europe is about 1560 cc. (44 cases); that of modern Europeans is the same (347 cases); of the Mongoloid race, 1510 cc. (68 cases); of African negroes, 1405 cc. (83 cases); and of negroes of the Pacific Ocean, 1460 cc. (46 cases). Here we have, therefore, a decided difference in favor of the white race. In interpreting these facts, we must ask, Does the increase in the size of the brain prove an increase in faculty? This would seem highly probable, and facts may be adduced which speak in favor of this assumption. First among these is the relatively large size of the brain among the higher animals, and the still larger size in man. Furthermore, Manouvrier has measured the capacity of the skulls of thirty-five eminent men. He found that they averaged 1665 cc. as compared to 1560 cc. general average, which was derived from 110 individuals. On the other hand, he found that the cranial capacity of forty-five murderers was 1580 cc., also superior to the general average. The same result has been obtained through weighings of brains of eminent men. The brains of thirty-four of these showed an average increase of 93 grams over the average brain-weight of 1357 grams. Another fact which may be adduced in favor of the theory that greater brains are accompanied by higher faculty is that the heads of the best English students are larger than those of the average class of students (Galton). The force of the arguments furnished by these observations must, however, not be overestimated.