Annoyed by the professor of anatomy who told racy stories
during class, a group of female students decided that the next time he
started to tell one, they would all rise and leave the room in
protest. The professor, however, got wind of their scheme just before
class the following day; so he bided his time. Then, halfway through
the lecture, he began, "They say there is quite a shortage of
prostitutes in France - " The girls looked at one another, arose and
started for the door. "Young ladies," said the professor with a broad
smile, "the next plane doesn't leave till tomorrow afternoon."