Book of Hours, Walters W.90, f. 67v: a knight charges an ape

Book of Hours, northeast France, early 14th century, Walters Art Museum, Baltimore, Ms. W.90, folio 67v. In the lower margin a knight on horseback levels his lance, not at a rival knight, but at the backside of an ape. The same little prayer book stages apes jousting on horseback and another knight hacking at an ape with a sword, so the painter clearly found the idea of chivalry versus monkeys endlessly funny.