Very remarkable is the influence, demonstrated especially by _Lombroso_, exercised by menstruation on the commission of certain crimes. Of eighty women taken into custody for resisting the police, there were nine only who were not menstruating at the time. Four notorious murderesses and one woman convicted of arson were all menstruating at the times when their crimes were committed. _Krugenstein_ found evidence of menstruation in the bodies of 107 women who committed suicide. Thefts committed by ladies in the great shops of Paris are most commonly effected during menstruation, as was found by _Legrand du Saulle_ to be the case in thirty five instances out of fifty-six investigated by him in respect to this matter. According to the same author, hysterical girls who steal articles of clothing, bottles of scent, and the like, from the counters of shops, are almost always menstruating at the time. _Von Krafft-Ebing_ puts forward the following propositions with regard to the forensic significance of offences committed by women during menstruation: 1. The mental integrity of a menstruating woman is questionable from the forensic standpoint. 2. In the case of women on trial for any offence, the point should be determined whether that offence was committed at a menstrual period. 3. An inquiry into the mental condition is expedient in cases in which such a coincidence is established; light is thrown on the matter when investigation shows the existence of hereditary predisposition, when we learn that psychopathic manifestations have occurred at previous menstrual periods, or when the very nature of the offence is one suggesting the presence of mental disorder. 4. A recognition of the powerful influence which the menstrual process exercises upon the mental life should lead, even in cases in which no menstrual psychosis has been proved to exist, to the admission of extenuating circumstances in apportioning the punishment for the offence. 5. In the case of the commission of a punishable act during menstruation by a weak-minded individual, we must as a rule admit the plea of irresponsibility—at any rate in the case of an offence committed under the influence of strong emotion. 6. Persons who have been discharged without punishment on the plea of mental disorder accompanying menstruation must be regarded as dangerous to the community, and should always be under careful supervision during the menstrual periods. _Amenorrhœa, Menorrhagia, and Dysmenorrhœa._