William Sermon's 1671 medical book The Ladies Companion, Or The English Midwife reveals his strange fascination with hares.
Sermon (c1629-1680) is said to have decided to study medicine after witnessing a woman giving birth alone in a wood while he was out hare-shooting – which may explain why hares feature so prominently in his cures.
"Take the slime that a hare will have about his mouth when he eateth mallows and drink it in wine," Sermon instructs his readers. "Two hours after lie with your husband and fear not (faith my author) but that you will conceive."
Another remedy Sermon recommends to husbands is to secretly feed their wives the womb of a hare. "Give to the woman without her knowledge the womb of a hare to eat. Or burn the same to powder, and give it to her in wine to drink." [Link]