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!

Alice's Adventures in Wonderland & Through the Looking-Glass