The editor of one edition of the Natural History adds a footnote to say that Pliny’s accounts are “entirely without foundation.” But they were built upon centuries of belief about the power of the menstrual woman and others built upon them in turn. It’s telling how many of the Pliny powers were judged to be witchcraft. Menstruation must have been unsettling. How could women bleed and not die, when men bled and did?

