The influence of latitude and climate is evident for widely different climates, and has been exaggerated by a number of writers. We may say in a general way that menstruation is more precocious as we near the Equa tor, more backward as we near the cold countries. Tarnier and Chan treuil, set this epoch at between twelve and eighteen years for temperate climates, from eleven to fifteen for hot climates, and from thirteen to twenty-one for cold climates. The average temperature is also of impor tance. Under the influence of heat the number of precocious menstru ations increases, and that of tardy menstruations decreases. The contrary happens under the influence of cold.
City life or country life, the method of education, and the diet, all af fect the period of the first menstruation. Women in cities menstruate sooner than women in the country, women of the working class before children of the wealthy; but great allowance must be made for the de moralization existing in the work-shops and factories, which, by develop ing the genital instinct, leads to precocity in the menstrual function. On the other hand, insufficiency or bad quality of food often retards puberty, while a rich diet, and a life of luxury and pleasure, hasten its appearance.
A curious phenomenon is called the vicarious menstruation. This may occur in two ways: in one, the menstrual discharge takes place, but in a minimum degree, and, at the same time, a hemorrhage from some other organ than the uterus is produced. This is principally from the lungs, pituitary body, or intestinal canal, or in the sub-cutanous cellular tissue, (the breasts, of which we have had an example). These hemorrhages form the supplementary menses. In the other instance, there is no uterine hemorrhage, and it is replaced by a bloody discharge from the lungs, intestine, nose, mouth, surface of a sore, of an erectile tumor, or the skin. (Jacquemier). Courty says that in these cases this vicarious menstruation stops if pregnancy occurs; appearing again after confine ment, thus acting like the true menses.
Sometimes the menstrual hemorrhage takes place on the internal sur face of the uterus, but the blood does not flow to the exterior, being re tained in the interior of the uterine cavity or the vagina, by a partition of the vagina, an imperforate hymen, in a word a defect of formation of the uterus, cervix, the vagina, or of the vulva. This phenomenon, which may cause grave results, is called retention of the menses. Iu
other cases, the flow occurs accompanied by extreme suffering, and the woman ejects a true membranous sac, or at least shreds of membranes, the microscopic examination of which demonstrates it to be exfoliated uterine mucosa, really degenerated as at confinement. This form of menstruation is called pseudo-membranous dysmenorrhoea.
Characteristics of the Menstrual Blood.
The quantity of blood lost by women at each menstrual period is ex tremely variable; thus the figures given by writers vary from eighteen ounces to three ounces. These differences are explained not only by in dividual variations, but also by the difficulty of estimating the exact quan tity of blood contained in the menstrual flow, which is always mixed with the mucous secretions of the vagina and uterus. Besides, exactness is still more difficult, because, although there are women who only lose a few ounces of blood, there are others who lose upwards of eighteen ounces. This hemorrhage, which certainly would be excessive for some, is on the con trary admirably borne by others, and does not affect their health. Never theless, the average can be placed at from three to six ounces. The quan tity of blood lost varies in the same woman, according to her diet, health, exercise, abuse of the sexual relation, condition of health or sickness, and consequently there is nothing fixed. There are three stages of the men strual discharge, corresponding exactly with the anatomical changes of the uterine mucous membrane. At the start, the glandular activity predom inates; the natural consequence of this is that mucous discharges predom inate, the fluid is slimy, with a penetrating odor; it is more or less colored, either a light or dark red, and, under the microscope, numerous epithelial cells are found, which come from the mucous membrane of the uterus and vagina, and a large quantity of mucous globules coming from the glands, the whole mixed with red globules more or less numerous and unchanged. In the second stage, the blood is almost pure. The dis charge is then liquid, slightly slimy, and deep red like venous blood. Finally the third stage or period of decrease arrives. The diminution in the number of blood globules, the increase of the mucous secretion, re stores its first character with this difference, that the epithelial elements are very few.