The white whale, or beluga, is something like a large narwhal without a tusk, and is also a dweller in the northern seas. But it often ascends the larger rivers for hundreds of miles in search of fish. Now and then it has been killed off the coasts of Scotland, and one example lived for quite a long time in the Firth of Forth, going up the river day after day as the tide came in, and always retreating as it began to fall. The fishermen were very anxious to kill it, because of the quantities of fish which it devoured. But it was so quick and active that it eluded them over and over again, and three whole months passed away before at last they succeeded. In one or two of the great rivers of North America white whales are regularly hunted, the animals being first driven up the stream, and then caught with nets as they return. They yield a large quantity of very pure oil, and the "porpoise-hide," which is used so largely in making boots and shoes, is in reality prepared from their skins. THE TRUE PORPOISE The true porpoise, or sea-hog, is much more widely distributed. It likes to tumble and gambol on the surface of the sea quite close to the shore. It will ascend tidal rivers too. Its range is mainly along the Atlantic coast, and it is also found on coasts of Europe and in the Pacific Ocean. Chasing porpoises in canoes, and spearing them, is an exciting Canadian sport. Porpoises have a curious way of swimming, for they travel along by a series of bounds, first of all leaping almost out of the water, and then diving under it. When a number of them are moving along in this way one behind the other, as they very often do, they look from a little distance just like an enormous snake winding its way through the water, and no doubt have given rise to some of the tales about the great sea-serpent. A herd of porpoises will frequently follow a sailing ship for days, sometimes, apparently, out of pure curiosity, and sometimes in the hope of picking up something eatable among the rubbish that is thrown overboard. But they are very much afraid of steamships, and always keep at a respectful distance from them. They feed chiefly on fish, and are so quick and active that even the salmon cannot escape from them, while they will follow up shoals of mackerel and herrings and destroy them in enormous numbers. When fully grown the porpoise is rather more than five feet long. The upper part of the body is almost black in color, becoming paler on the sides, while the lower surface is almost pure white. THE GRAMPUS