The natural odor of the menstrual discharge is peculiar, but not offensive. It is an odorsui generis,and has been compared to that of the marigold(calendula officinalis), fish brine, etc. It is most pungent in women of darker or lighter complexion, e. g., in negro and in red-haired women it is often very strong. Virchow attributes it to the presence of fatty acids. But it is not the peculiar natural odor pervading menstruants that we wish to bring to the attention of the reader. It is the abnormal odor contracted by the flux at or before its emergence from the uterus. To differentiate the two in all cases may become difficult, but the distinction must be borne in mind while endeavoring to make a proper diagnosis. Every physician of experience no doubt has had—like myself— a number of cases of fetid menstruation—Fluxus Menstrualis Fœtidus—for which I would propose,