reproduction,"²⁷ the female choosing to pair with the more attractive male, or the stronger male prevailing in a contest for the female. Wallace²⁸ advanced the opposite view, that the female owes her soberness to the fact that only inconspicuous females have in the struggle for existence escaped destruction during the breeding season. There are fatal objections to both these theories; and, taking his cue from Tylor,²⁹ Wallace himself, in a later work, suggested what is probably the true explanation, namely, that the superior variability of the male is constitutional, and due to general laws of growth and development. "If ornament," he says, "is the natural product and direct outcome of superabundant health and vigor, then no other mode of selection is needed to account for the presence of such ornament."³⁰ That a tendency to spend energy more rapidly should result in more striking morphological variation is to be expected; or, put otherwise, the fact of a greater variational tendency in the male is the outcome of a constitutional inclination to destructive metabolism. It is a general law in the courtship of the sexes that the male seeks the female. The secondary sexual characters of the male are developed with puberty, and in some cases these sexual distinctions come and go with the breeding season. What we know as physiological energy is the result of the dissociation of atoms in the organism; expressions of energy are the accompaniment of the katabolic or breaking-up process, and the brighter color of the male, especially at the breeding season, results from the fact that the waste products of the katabolism are deposited as pigments.

When we compare the sexes of mankind morphologically, we find a greater tendency to variation in man:³¹

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 Weisbach³⁵ 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.

The form of woman is rounder and less variable than that of man, and art has been able to produce a more nearly ideal figure of woman than of man; at the same time, the bones of woman weigh less with reference to body weight than the bones of man, and both these facts indicate less variation and more constitutional passivity in woman. The trunk of woman is slightly longer than that of man,³⁷ and her abdomen is relatively more prominent, and is so represented in art. In these respects she resembles the child and the lower races, i.e., the less developed forms.³⁸ Ranke states that the typical adult male form is characterized by a relatively shorter trunk, relatively longer arms, legs, hands, and feet, and relatively to the long upper arms and thighs by still longer forearms and lower legs, and relatively to the whole upper extremity by a still longer lower extremity; while the typical female form approaches the infantile condition in having a relatively longer trunk, shorter arms, legs, hands, and feet; relatively to short upper arms still shorter forearms, and relatively to short