When the Whale feeds, it swims with considerable velocity below the surface of the sea, with its jaws widely extended. A stream of water consequently enters its mouth, carrying along with it immense quantities of cuttle-fish, sea-blubber, shrimps, and other small marine animals. The water escapes at the sides; but the food is entangled, and, as it were, sifted by the fringe of whalebone within the mouth; this kind of strainer is rendered necessary by the very small gullet, which in a Whale of sixty feet long, does not exceed four inches in width. The sailors say that a penny-loaf would choke a Whale. The Whale bellows fearfully when wounded or in distress. Its young is called a cub. There is also an extensive Whale fishery in the Southern Ocean, carried on chiefly by the Americans. The Whale found in those seas is distinct from the Greenland Whale, and is described by naturalists under the name of _Balæna Australis_. [Illustration] THE RORQUAL, OR FIN-BACKED WHALE, (_Balænoptera boops_,) IS a very large Whale, specimens sometimes measuring as much as one hundred feet in length. It is distinguished by its smaller head, and by the existence of a sort of fin on the lower part of its back. The Rorqual is found in the northern seas, and specimens are sometimes seen off our coasts. It is not of much value, as it furnishes far less blubber than the common Whale, and the baleen or whalebone is so short as to be useless. [Illustration: THE SPERMACETI WHALE, OR CACHALOT. (_Physeter macrocephalus._)] THIS animal has teeth in the lower jaw only; and no whalebone. The substance called spermaceti is extracted from its immense head, which is nearly half the size of the entire animal; and the throat is so large that it could swallow a shark. The quantity of oil produced from the Spermaceti Whale is not so considerable as that obtained from the common or Greenland Whale, but in quality it is far preferable, as it yields a bright flame, without exhaling any nauseous smell. The substance known by the name of ambergris is also obtained from the body of this animal. It is generally found in the stomach, but sometimes in the intestines; and, in a commercial point of view, is a highly valuable production. The spermaceti is in a fluid state while the animal is living, and as soon as it is dead a hole is made in the head, and the liquid taken out with buckets. It becomes solid as it cools, and it is afterwards made into candles, &c.