Neither should parents be too tender of their daughters at this period. Especially should the reading of novels and books of an exciting nature, the attendance of balls, parties, theaters, etc., be avoided; and persons of whatever sex should be particularly careful to treat those of this age with the utmost kindness in every respect. One unkind look, one harsh expression, or one angry word from a parent or near friend, may be the means of affecting severely the individual’s health. It has been a question with some, as to whether menstruation is strictly a natural function to the human system. So far as we know, it has occurred in all climates and in all periods of time. We read in the Levitical law, “If a woman have an issue of blood in her flesh, that she be put away seven days, and that whoever toucheth her shall be unclean.” The cases of Rachel and of Sarah every one may recollect. Naturalists tell us, too, that some of the monkey tribes, or species of animals nearest resembling man, have symptoms of this kind. Still there have been those who believed that this function has come upon the human race in consequence of great and long-continued physical transgressions, continued, perhaps, through ages and ages, until at length it took on the form of an apparently natural function. SOURCE OF THE MENSES. From whence comes the menstrual discharge? This has been a question which has caused a good deal of dispute on the part of some. The majority of writers, of all ages, agree in regarding the menstrual flow as coming from the womb; yet some have held that it issues only from the vagina and more external parts. This latter supposition cannot hold good except, possibly, now and then, as an exception to the general rule. Blood may exude from any part of the body, from the vagina and external organs of generation, as well as from the womb. But this organ, beyond doubt, is the great and principal source of the menstrual discharge. PERIODICITY. The periodicity of this function is remarkable. With those who are regular, menstruation occurs every twenty-eight or twenty-nine days, or once a lunar month. There is, however, considerable variation from this rule. Some having menstruation twice a year appear to enjoy very good health. Some have asserted that the frequency of menstruation varies considerably according to climate. Linnæus, it seems, saw women in Lapland who menstruated about once a year. Dr. Denman speaks of the inhabitants of Lapland, where women do not menstruate till they arrive at mature age, and then only in small quantities and at long intervals, and sometimes only in summer. But if they do not menstruate according to the genius of their country, it is said they suffer equal inconvenience, as in warmer climates, where the quantity discharged is much greater and the period shorter. NATURE OF THE MENSTRUAL DISCHARGE.