The blood of women shows a larger percentage of water, a smaller quantity of blood-globules, and a smaller quantity of hemachrome. With woman the smaller size of the heart, the narrower vascular system, and probably also the larger percentage of water in the blood, cause a less intense assimilation of matter and an inferior nutrition. This may also account for the weaker jaws. “It may thus be explained that even civilized man in many respects is more closely connected with the animal world, especially the ape, than woman, that he possesses pithecoid traits which may be seen in the shape of the skull and the length of the limbs.” In regard to the differences of the skull of both sexes, let it be stated that, according to Bartels, there is no absolute indication whereby we could determine whether a skull belonged to a male or female person. Absolute comparison shows that the skulls of men are larger in all dimensions. Accordingly the weight is greater, too, and the interior space is larger. As a medium weight of normally developed brains of adult persons, Grosser states 1388 grammes for the man and 1252 grammes for the woman.[150] The great majority of male brains (34 per cent.) weigh between 1250 and 1550 grammes, and the great majority of female brains (91 per cent.) weigh between 1100 and 1450 grammes. But these weights are not subject to direct comparison since woman is smaller than man. It is, accordingly, necessary to determine the weight of the brain in proportion to the body. When we compare the weight of the brain with the weight of the body we find that with the man there are 21.6 grammes of the brain for every kilogram of the weight of the body, and with the woman there are 23.6 grammes. This outweighing is explained by the fact that woman’s stature is smaller.[151] Different results are obtained by a comparison of equally large individuals of both sexes. According to Marchand the weight of the female brain is, without exception, lighter than that of men of the same size. But this method is as incorrect as a comparison with the size of the body. It takes for granted what remains to be proven: a direct relation between the size of the body and the weight of the brain. Blakeman, Alice Lee and Karl Pearson have determined on the basis of English data and measurements, that there is no noticeable relative difference in the weight of the brain between man and woman; that is, a man of the same age, stature and skull measurements as the average woman, would not differ from her in regard to the weight of his brain.[152]