=Similarity of changes in the sexes.=--Men and women are complements of each other. They have two correspondingly important and similar periods in life. In man, the first is when the genital glands begin to secrete procreative life. This usually occurs when he is from fourteen to fifteen. This change indicates that nature has begun her work of preparing the male genital organs for their primal function--fatherhood. Nature’s processes work gradually. She is apparently in no hurry. If not interfered with, she will accomplish a perfect work. Hence we find, that while nature is preparing the boy for fatherhood, this function is not possible for three or four years after the change begins; and that the function performed at this time would mean a defective child. Careful investigations show that among children whose fathers married at [Illustration: WELL PRESERVED AND CONTENTED IN OLD AGE] twenty or younger, eight to ten per cent. more of these children die in the first year than among children whose fathers married at twenty-four or later. This would indicate that the sexual life of the male has a double creative function. The first is to create a father, which requires eight to ten years. This, however, is only preparatory to the second, the primal function of fatherhood. The second change in man occurs when he is from forty-five to fifty-five and the physical indications are that this period of procreation should close. In woman, the first important period usually occurs from twelve to fourteen, when the functions of menstruation and ovulation begin. The change indicates that nature has begun her work of fitting the female genital organs for their primal function--motherhood. In woman as in man, nature takes her own time. As a rule motherhood would not be possible for a year or two after this change has begun. Even then the child would reveal defects. Carefully gathered facts show that among children, whose mothers married at sixteen, four to five per cent. more die in the first year than among children whose mothers married at or near twenty. This would indicate that the sexual life of the female has a double creative function. The first is to create a mother, which requires a period of six to eight years. This, however, also is only preparatory to the primal functions of the sexual life--motherhood. The second change in a woman’s life occurs when she is from forty to forty-nine and the physical changes which occur bring her procreative period of life to a close.