If that was the one where Mark's friend puts the jujube in the teacher's book, the teacher was the same actor who later played Kodos the Executioner in the Star Trek season 1 episode "Conscience of the King."
I love watching the old TV shows that feature actors before I first saw them as a kid. Earlier on Saturday was the episode of The Big Valley where the old gypsy grandmother was played by the actress who later played the Vulcan Priestess T'Pau in the episode "Amok Time."
-PJ
Roger on the jujube. Then the boys cut class and hide in a mine, mine caves in, yada, yada, yada....