The duck hunter trained his retriever to walk on water. Eager to show off this amazing accomplishment, he asked a friend to go along on his next hunting trip. Saying nothing, he fired his first shot and, as the duck fell, the dog walked on the surface of the water, retrieved the duck and returned it to his master. "Notice anything?" the owner asked eagerly. "Yes," said his friend, "I see that fool dog of yours can't swim."