In deepest Africa an explorer discovered a lake in which there lived a race of intelligent porpoise. He learned to communicate with these porpoises and they quickly learned to speak and to read and write.

They told him that they had live in the lake for thousands of years and they were essentially immortal. When the explorer told the world about the wisdom of these porpoise, people from all over the world began to write letters to them asking for help and advice.

There was no postal service to this remote lake so the mail just collected at the post office and the postal service refused to deliver it without special delivery postage. But because of the international prestige the government at last agreed to deliver the mail for free.

Because the lake was so remote there was no road and the postal service had to send a postman with bearers carrying the mail in sacks. As they approached the lake they came upon a large lion sleeping directly across the narrow path.

After some deliberation, the postman told the bearers to just step over lion very carefully so as not to wake him.

They were just starting to do so; when a policeman sprang from the brush and said, "You're all under arrest! Don't you know it's illegal carry free mail across a sedate lion for immortal porpoises!"