" When we were little," the Mock Turtle went on at last, more calmly, though still sobbing a little now and then, "we went to school in the sea. The master was an old Turtle - we used to call him Tortoise -"
"Why did you call him Tortoise, if he wasn't one?" Alice asked.
"We called him Tortoise because he taught us," said the Mock Turtle angrily: "really you are very dull! "

― Lewis Carroll , Alice's Adventures in Wonderland / Through the Looking-Glass