Malleus Maleficarum
“…the witches themselves have often been seen lying on their backs in the fields or the woods, naked up to the very navel, and it has been apparent from the disposition of those limbs and members which pertain to the venereal act and orgasm, as also from the agitation of their legs and thighs, that, all invisibly to the bystanders, they have been copulating with Incubus devils…”