The signs of puberty in girls were noticed and explained in very early times. From the anthropological studies of _Ploss_ and _Bartels_ we take the following data regarding this matter. In the Bible we read (Ezekiel, xvi, 7): “Thy breasts are fashioned and thine hair is grown, whereas thou wast naked and bare.” The early Indian physician, _Susruta_, refers only to the regular recurrence of menstruation as a sign of puberty. That a woman is menstruating may be known by the fact that her face is swollen and bright. In the Roman Empire _Justinian_ ordained that all young women should be examined as to the growth or absence of the pubic hair in order to ascertain if they were ripe for marriage. The early Chinese physicians recorded that in every woman at the age of fourteen or fifteen years a monthly flow of blood from the genital organs began, the period of recurrence being thirty days. The physicians of the Talmud express themselves variously regarding puberty in women. In one place they advance as a sign of puberty the growth of the hair on the genital organs; in another they speak of the notable enlargement of the breasts, and mention as a sign of more complete sexual development that the nipples become elastic. Other Talmudists refer to the appearance of a dark brown coloration in the areola and to the enlargement of the mons Veneris as signs of puberty. Savage races regard the first appearance of the menstrual flow as the only certain sign of puberty, and among many such races this is the occasion of peculiar ceremonial rites. The attainment of puberty in savage tribes is often solemnized by the seclusion of the girls from the time of the first menstruation; they fast during the period of seclusion, which sometimes terminates in an elaborate ritual of purification.
For two reasons in particular, the period of the menarche is a time of storm and stress to women, first on account of the developmental processes in the genital organs, and secondly on account of the intellectual changes that occur at this period.
The local cause is to be found in the extensive transformation of the ovaries and the uterus, by means of which a peculiar and powerful stimulus, the menstrual stimulus, is elaborated, which has a reflex influence upon heart and brain, vascular and nervous systems, and secretory and nutritive processes. Since we know that in every premenstrual period by the growth of the follicles hyperæmia is excited in the ovary, by means of which the liquor folliculi is increased in amount, we can well understand that at the time of the menarche the ripening of the graafian follicles is accompanied by a considerable degree of hyperæmia of the ovaries and of the whole of the genital organs, now undergoing their fullest development, and we can easily see how this hyperæmia may result in manifold reflex disturbances. But in addition to these reflex disturbances, we have once more to take into consideration the as yet imperfectly known chemical processes which are associated with the ripening and development of the graafian follicles, and an abnormal course of which may give rise to a disordered constitution of the blood, manifesting itself as chlorosis or in other ways. In connection with the growth and ripening of the ova, extensive and novel demands are made on the organism, and these may well endanger metabolic processes which are not established on a very secure foundation.