Thus, on the whole, one is inclined to suppose that the general resemblance in facial appearance, bodily contour, and interests which we observe in children of the two sexes, indicates that deeper distinctions are latent rather than active. This is much more than an academic question, for if our subject in the present volume were the care of childhood, it is plain that we should have to base upon our answer to this question our treatment of boy and girl respectively. Probably we are on the whole correct in instituting no deep distinction of any kind in the nurture, either physical or mental, of children during their early years. Nor can there be any doubt, at least so far, as to the rightness of educating them together, and allowing them to compete, in so far as we allow competition at all, freely both in work and in games. However this may be, there comes at an age which varies somewhat in different races and individuals, a period critical to both sexes, in which the factors of sex differentiation, hitherto more or less latent, begin conspicuously to assert themselves. Here, plainly, is the dawn of womanhood, and here, in our consideration of woman the individual, we must make a start. If we recall the tentative Mendelian analysis already referred to, we may suppose that the "factor" for womanhood begins to assert itself, at any rate in effective degree, at this period of puberty, when a girl becomes a woman; and that its most effective reign is over at the much later crisis which we call the change of life or climacteric. In other words, though sex is determined from the first, and though certain of its distinctive characters remain to the end, we may say that our study of womanhood is practically concerned with the years between twelve or thirteen, and forty-five or fifty. Before this period, as we have suggested, the distinction between the sexes is of no practical importance so far as _regimen_ and education are concerned. After this period also it is probable that the difference between the two sexes is diminished, and would be still more evidently diminished were it not for the effects which different experience has permanently wrought in the memory. We begin our practical study, then, of woman the individual, with the young girl at the age of puberty; and we must concern ourselves first with the care of her body. VIII THE PHYSICAL TRAINING OF GIRLS We shall certainly not reach right conclusions about the physical training of girls unless we rightly understand what physical training does and does not effect, and what we desire it should effect. This applies to all education--that our aim be defined, that we shall know "what it is we are after," and it applies pre-eminently to the education, both physical and mental, of girls.