Everybody knows the wonderful story of Arion, who having been forced by pirates to leap into the sea, proceeded merrily to his journey's end on the back of a dolphin:-- "Secure he sits, and with harmonious strains Requites his bearer for his friendly pains. The gods approve, the dolphin heaven adorns, And with nine stars a constellation forms." Pliny relates the no less astonishing tale of a boy at Baiæ, who by feeding it with bread, gained the affections of a dolphin, so that the thankful creature used to convey him every morning to school across the sea to Puteoli, and back again. When the boy died, the poor disconsolate dolphin returned every morning to the spot where he had been accustomed to meet his friend, and soon fell a victim to his grief. The same naturalist tells us also that the dolphins at Narbonne rendered themselves very useful to the fishermen by driving the fish into their nets, and were generously rewarded for their assistance with "bread soaked in wine." A king of Caria having chained a dolphin in the harbour, its afflicted associates appeared in great numbers, testifying their anxiety for its deliverance by such unequivocal signs of sorrow, that the king, touched with compassion, restored the prisoner to liberty. Such, and similar fables, which were believed by the naturalists of antiquity, are laughed at even by the old women of our times. The dolphin is in no respects superior to the other cetaceans; his musical taste is as low as zero, and if, like the bonito and albacore, he follows a ship for days together, it is most surely not out of affection for man, but on account of the offal that is thrown overboard. But do not many human friendships repose on similar selfish motives? [Illustration: The Porpoise.] The Porpoise (_Delphinus Phocœna_), which only attains a length of five or six feet, and seems to be the smallest of all cetaceans, is frequently confounded with the dolphin. It is at home in the whole Northern Atlantic, in the Mediterranean, and the Euxine. While the dolphin prefers the high sea, the porpoise loves tranquil bays and cliff-sheltered shores, and often swims up the rivers, so that individuals have been caught in the Elbe and Seine as high up as Dessau and Paris. The porpoise is a no less excellent swimmer than the dolphin, making at least fifteen miles an hour. His rapidity and sharp teeth render him a most dangerous enemy to all the lesser fry of the ocean, whose sole refuge lies in the shallowest waters. When he rises to the surface to draw breath, the back only appears, the head and tail are kept under water. At the entrance of harbours, where he is frequently seen gambolling, his undulatory or leaping movements, now rising with a grunt, now sinking to reappear again at some distance, afford an entertaining spectacle.