We observe again a difference in the ages between those who are reared in the country or rural districts and the dwellers in the cities, whether it be in luxurious apartments or in tenement houses. The former grow older and stronger than the latter before the show begins.
The temperament also greatly influences the development of the function; children who are nervous, irritable, and of a sanguineous temperament, menstruate earlier than those of sedate habits.
The color of the hair and complexion are also indices of the respective appearance of the menses in the brunette and blonde. It has been observed that the dark-complexioned girls menstruate sooner under similar conditions than the blondes. Weakly children, who are delicate from some constitutional habit, or whose organism has suffered from disturbances of indigestion or suffered severely from teething in early childhood, menstruate earlier than their stronger and robust sisters.
The quantity of the natural menstrual discharge, as well as the time or duration, varies greatly in health with different individuals. We first notice a slimy discharge, which soon becomes tinged with blood, and after one or two days it is almost of pure blood. The flow generally lasts three or four days, very seldom only one day, and sometimes a week to ten days.
The monthly recurrence of the menstrual periods averages thirty years; in temperate climates it may overreach this figure a little, while in hot climates it comes much below this average.
It does not follow as a rule that because a woman began to menstruate quite young, the change of life will take place earlier. This also depends much upon temperament, habit and mode of life.
Physiologists have established, by carefully-prepared statistics, that the average period of menstruation for women who began to menstruate early is thirty-three years, while those who commenced late have an average of only twenty-seven years.
When a woman is forty-five years of age, we may, however, as a rule, look for the change of life to set in; if she goes beyond this age, she may be taken as the exception.
The cavity of the womb is the principal source from which the blood comes; while the ovaries and tubes are also greatly congested with blood, the amount that comes from them must be very small.