=Its Appearance.=--First there is a slight discharge of mucus which soon becomes of a rusty brown or yellow color from the mixture of a small quantity of blood. By the second or third day the discharge has the appearance of pure blood. The unpleasant sensations which were so marked at first now gradually subside, and the discharge, after continuing for a certain number of days, grows more and more scanty. The color changes from a pure red to a rusty tinge, and finally disappears altogether. Then the ordinary duties are resumed. =The Age of Puberty.=--Menstruation begins at about fourteen or fifteen years of age, this period being known as "the age of puberty." It is preceded and attended by peculiar signs. The whole figure becomes more plump and round, the hips increase in breadth, and the breasts rapidly develop. The more striking changes, however, occur in the inclinations and emotional susceptibilities. =Age Modified.=--A great many circumstances modify the age at which the first menstruation takes place. In hot climates this takes place earlier, the difference between hot and cold countries being as great as three years; yet heredity has more to do with this than anything else. "As was the mother so is the child" is a common saying among women. =Continues About Thirty Years.=--The menstrual function continues active from this age until about the forty-fifth year, although this may be extended even ten years later. During all these years the woman is capable of bearing children, because at each month there has been a fully developed ovum, or egg, ready to be fertilized. =The Change of Life.=--When the menstrual function ceases, then the period of childbearing is over. The time of its disappearance is known as "the change of life, or menopause." =Amount of Monthly Loss.=--The amount of blood lost during menstruation varies greatly with different individuals, and it would be quite impossible to give anything like an accurate rule. It varies, normally, from one to eight ounces, the average being probably about five ounces. =Duration of Period.=--The duration of the period is from one to eight days, the average being five days. Hence it will be seen that the average loss of fluid per day would be about one ounce. =Loss Should Be Small.=--It should be stated here that, as a rule, those enjoy the best health who lose but a small quantity of blood at this time. Some persons seem to think that a very free discharge is necessary, and that they feel better at such times; but there is no possible reason why this should be the case.