All the secondary sexual characters of man are highly variable, even within the limits of the same race; and they differ much in the several races.... Numerous measurements carefully made of the stature, the circumference of the neck and chest, the length of the backbone and of the arms, in various races ... nearly all show that the males differ much more from one another than do the females. This fact indicates that, as far as these characters are concerned, it is the male which has been chiefly modified, since the several races diverged from their common stock.[32] Morphologically the development of man is more accentuated than that of woman. Anthropologists, indeed, regard woman as intermediate in development between the child and the man. The outlines of the adult female cranium are intermediate between those of the child and the adult man; they are softer, more graceful and delicate, and the apophyses and ridges for the attachment of muscles are less pronounced,... the forehead is ... more perpendicular, to such a degree that in a group of skulls those of the two sexes have been mistaken for different types; the superciliary ridges and the glabella are less developed, often not at all; the crown is higher and more horizontal; the brain weight and cranial capacity are less; the mastoid apophyses, the inion, the styloid apophyses, and the condyles of the occipital are of less volume, the zygomatic and alveolar arches are more regular.[33] Wagner decided that the brain of a woman, taken as a whole, is uniformly in a more or less embryonic condition. Huschke says that woman is always a growing child, and that her brain departs from the infantile type no more than the other portions of her body.[34] Weisbach[35] pointed out that the limits of variation in the skull of man are greater than in that of woman. Several observers have recorded the opinion that women of dolichocephalic races are more brachycephalic, and women of brachycephalic races more dolichocephalic, than the men of the same races. If this is true, it is a remarkable confirmation of the conservative tendency of woman. "I have thought for several years that woman was, in a general way, less dolichocephalic in dolichocephalic races, and less brachycephalic in brachycephalic races, and that she had a tendency to approach the typical median form of humanity."[36] The skin of woman is without exception of a lighter shade than that of man, even among the dark races. This cannot be due to less exposure, since the women and men are equally exposed among the uncivilized races, but is due to the same causes as the more brilliant plumage of male birds.