This illustration from a French _Book of Hours_ dating c. 1475 depicts a bleeding Eucharist wafer that medieval people considered miraculous. It even has a name: “the Sacred Bleeding Host of Dijon.” Medieval people were spellbound by miraculous bleeding communion wafers such as this one, but there was an ugly underside to this devotion: it encouraged anti-Semitism. Jews were frequently the targets of violence by Christians, who wanted to exact revenge because they accused Jews of desecrating the hosts and making them bleed. Of course, not a single accusation was grounded in evidence – a fact which the Church hierarchy frequently acknowledged. Indeed, there is a micro-organism called “micrococinus prodigiosus” which might have been responsible for the red speckles on the bread.