At present housework, especially in the country, affords wearying labor which is not so well adapted to the development of physical strength as it might be because it is not systematic. Certain parts of the body are overexercised and certain parts are neglected. The result is frequently a body with a semblance of strength but with, as you might say, strands of weakness, rendering it liable to fall at the least onslaught of infection or unusual strain. These lacks should be made up for by consistently arranged exercises, by carefully studied diet, and by proper sleeping plans, so that there may be rightly developed muscular force--not too much and yet enough; so that there may be perfect circulation; fat enough and not too much; and that there may be a full supply of energy. If the young woman is vain enough to wish not to be portly when she is forty, she must not wait till she is forty-five to go to work at it; she should begin at twenty to train for that special form of beauty; if she does this she will soon express it in trimness, in an energetic and graceful step, in the exact curve of the spinal column at the small of the back, the right lift of the chest beneath the neck, and the perfect position of chin, elbows, shoulder blades, hips, feet, and all the parts of the body, for walking, sitting, standing, running, sleeping, and for every possible activity. Beauty is a thing to be valued and worked for; but a greater motive for the attention necessary to the full development of our physical powers is that we should be able to give to our children the greatest allotment of beauty and vigor that we can possibly command. Miss Goldmark in her valuable study, _Fatigue and Efficiency_, says that the results of overstrain in the labor of women are manifest in a heightened infant mortality, in a lowered birth rate, and in an impaired second generation. We should take this to heart. Not to make a struggle to increase our store of vigor for the sake of the children that are to be is to do them a great wrong. For girls under twenty the responsibility of the mother is greater because so much depends upon the establishment of the daughter's health during these earlier years. But girls themselves should take it upon their own responsibility to a large extent also. In the appendix to this volume will be found a bibliography where among the works published by the Young Women's Christian Association, the girl may find some that will answer many questions that perhaps have puzzled her in the period of swift growth between fifteen and twenty.