_Lawrence_ observed in young girls who from any cause suffered from amenorrhœa, that an increased pigmentation of the skin sometimes occurred, analogous to that met with in _Addison’s_ disease. This amenorrhoeic pigmentation he compares to the chloasma that is seen in pregnant women. By menorrhagia we understand the occurrence of typical discharges of blood from the uterus, occurring at more or less regular intervals and differing from normal menstruation in respect either of the greater intensity or of the longer duration of the hæmorrhage; whereas by metrorrhagia we understand the occurrence of atypical discharge of blood from the uterus, which is related to menstruation neither in respect to its causation nor in respect to the time of its appearance. Menorrhagia may be due to local changes in the genital organs, to organic diseases of other organs, and to general diseases. Local changes which may give rise to menorrhagia are, active hyperæmia and passive hyperæmia (hyperæmia from engorgement) of the genital organs, such hyperæmia being itself due to sexual excitement, especially when ungratified, to violent physical exercise, or to chill during menstruation; menorrhagia is also liable to occur when the abdominal circulation is disturbed by extreme obesity or by the presence of tumors, also in connection with endometritis, uterine myomata, erosions of the cervix, etc. Diseases of organs other than those belonging to the reproductive system which are especially likely to give rise to severe bleeding are, disease of the heart, such as valvular incompetence, lung disease, and nephritis. General diseases in which menorrhagia may occur are, anæmia, chlorosis, hæmophilia, scurvy, scarlatina, cholera, smallpox, influenza, and obesity. Through severe loss of blood in menorrhagia, whether the bleeding be sudden and profuse or more moderate but long continued, a condition of chronic anæmia results, with all its threatening consequences to the health and the life of the woman affected. She becomes pale and weak, unfitted for any great physical or mental exertion, and is liable to attacks of cardiac enfeeblement and to fainting fits; in some cases degenerative changes ensue in the cardiac muscle. Dysmenorrhœa is characterized by severe pain occurring before, during, and after menstruation. The pain is caused either by abnormally powerful contractions of the uterus or else by abnormal sensitiveness of that organ. Abnormally powerful contractions are caused by various mechanical hindrances to the normal processes of menstruation; abnormal sensitiveness is due to inflammatory and congestive states of the uterus and its annexa or to a general increase of nervous sensibility.