Among the six exceptions, one had been healthy until twenty-one, and then had suffered from ovaritis, so that, although engaging in the work of a healthy woman, she should really be classed apart. One was subject to epileptic convulsions, and may therefore be fairly ruled out for the same reason. The remaining three were in good, even robust, general health. In two, pain was experienced for two days, and a certain diminution of capacity for mental exertion, which, however, had never been sufficient to necessitate its interruption. One of these cases was a woman of thirty, who had been married for ten years without child-bearing. In the third case on the list, pain had never lasted more than six or twelve hours, and had been very greatly diminished during four years that the young lady had engaged in constant medical study. Finally, in the fourth case, the early years of adolescence were marked by quite severe dysmenorrhea, the pain only lasting, however, twelve hours. Between twenty-five and thirty, the pain disappeared, but the menstruation became menorrhagic (excessive). This was the only case on the list where no constant intellectual exertion had ever been made, but where the nervous system had been subjected to the strain of much moral emotion and anxiety. The girl belonged, moreover, to a family in which uterine disease was almost universal among the female members. While at first glance, therefore, it would appear that the proportion of women invalidated by menstruation was nearly as high as one-third, closer inspection shows that among these cases selected at random, the proportion is only one-fifth or one-sixth, if the calculation be confined to persons who had received much intellectual training. Among these cases, moreover, there is not one in which the period of suffering is as long as would be indicated by Dr. Clarke. Six, twelve, forty-eight hours is the outside limit. If extended beyond this, or even if very severe during this time, there is always reason to suspect actual disease of the uterus or ovaries, and the cases must be excluded from considerations only applicable to persons in average health. From this point of view, the week of rest demanded by Dr. Clarke, is as excessive as the three weeks' disturbance so imaginatively described by Michelet.