The Yakusha-banashi (役者論語) is a collection of advice and warnings for kabuki actors, by kabuki actors, compiled in the 1770s by (non-actor, I think) HACHIMONJA Jishō (八文舎自笑). This puts it somewhere between the invention of the revolving stage and the first performance of Tōkaidō Yotsuya kwaidan.

The collection starts off grandly with a chapter entitled "One hundred comments on stagecraft" (舞臺百ヶ條) by SUGI Kyūbei (杉九兵衛). "The truth of comedy arises from falsehood; the humor itself must come from truth." Hey, this isn't bad! you think. I bet I could sell this to MBAs as a two-day session for $400 a head. But then you reach the end of the seventh comment, and read this sentence:

是より下のヶ條は蟲ばみて見えず惜しむべし／＼

"The comments after this were eaten by insects and are illegible. How lamentable, how lamentable!"

Yeah, sure they were.