Note:  Do not rely on this information. It is very old.

Menstruation

Menstruation. The menstrual discharge usually manifests itself at about 14 or 15 years of age, and continues until the period of the climacteric, which occurs at about the 50th year. The discharge consists of blood, epithelium, and mucus. It lasts, as a rule, from three to six days, and recurs at intervals of a lunar month or thereabouts. The catamenial periods, as they are called, are accompanied, as a rule, by some lumbar pain and by a sense of fatigue; they are related in some way not precisely understood to the discharge of ova from the ovary. The menstrual discharge is absent, as a rule, during pregnancy and the period of lactation.