Attacks of menorrhagia in young girls are usually dependent on disturbances of the nervous system. Sometimes such an attack occurs at the very first menstrual period. Occasionally also menorrhagia may occur in association with chlorosis, to be distinguished according to _Virchow_ from a rare condition named by him “menorrhagic chlorosis,” characterized by excessive menstruation of an anticipating type. The bleeding is in such cases seldom very profuse, however, but the periods are very long, and the intervals exceedingly short. _Castan_ regards such profuse menorrhagia and metrorrhagia occurring in young chlorotic girls, especially at the commencement of puberty, as of an endoïnfective nature dependent upon auto-intoxication. The toxins lead to inflammatory and degenerative changes in the muscular substance of the uterus. According to _Frænkel_ in these cases the ovaries are usually enlarged, seldom smaller than normal. _Frœlich_ has discussed this subject exhaustively in his monograph on _Menorrhagia of Young Girls and Hypertrophy of the Cervix Uteri_.[21] He states that the cases of menorrhagia in young girls at the time of the menarche may be arranged in two groups. In one of these the patients are chlorotic, and menstruation is normal neither in amount nor in duration, but it is the long continuance of the flow rather than its profuseness that gives rise to danger; in the cases belonging to the other group the patients are in excellent health at the commencement of puberty, but menstruation soon takes the form of long-continued and profuse menorrhagia. Cases of the latter kind are due to hypertrophy of the cervix uteri and fungous metritis. Such attacks of menorrhagia in young girls are seen also in cases of infectious disorders, as in smallpox, measles, scarlatina, and above all, influenza. The hæmorrhage often begins in the first days of the infection, and even during the period of incubation, one or two days before the appearance of the general symptoms. If the patient is attacked by influenza while menstruating, the menstrual flow may assume the character of a true menorrhagia. More often, however, in such cases, we have to do with an extra-menstrual hæmorrhage, such as may indeed be observed in girls who have not yet begun to menstruate. _Inflammatory Processes._