Читать книгу The Circle of Knowledge: A Classified, Simplified, Visualized Book of Answers - Various - Страница 260

Under the general name of Cetacea, i.e., the Whales, are classed together a wonderful group of marine Mammalia, which includes not only the true whales, but also the Dolphin, Narwhal, Porpoise, and Grampus.

Notwithstanding their marked resemblance to fishes, the Cetacea possess the most indubitable mammalian character.

In the cetacea the bodies are elongated, fish-like, devoid of hair, and run out into a powerful caudal fin. The fore limbs are in the form of fins; there are no hind limbs. The cetacea are marine animals, and their food consists wholly of water animals and plants.

The whale is an astonishing animal, and in order that it may subsist a number of apparently contradictory conditions must be reconciled. It is a warm-blooded mammal, and yet spends its life wholly in cold water. In order to dive to great depths it must be able to make its body heavier than a corresponding bulk of water, and conversely at will make it lighter in order to reach the surface. Though breathing atmospheric air through nostrils, the animal can exist at a greater depth than where the pressure of the water would force its particles into solid oak, and yet no water can reach the whales’ lungs. It must be able to exist without breathing at all for at least the space of an hour. With the bones, ears, and eyes of a mammal it has to move, hear, and see as though it were a fish.

The “spouting” or “blowing” of the whale is simply an operation of purifying its blood. When the animal comes to the surface, it first expels the air in its lungs as it takes its first deep breath.

Dolphin (Delphinus delphis).—The dolphin is grey or greenish black on its upper parts, and white beneath. It generally attains a length of six feet, and lives in herds in all the northern seas. Hundreds of these swift animals are often seen around vessels, and amuse the passengers by their playful gambols. They feed chiefly on fish.

Greenland Whale (Balæna mysticetus).—This whale is greyish black on its upper parts, and white beneath. It is from forty-eight to seventy-two feet long, and weighs upwards of twenty thousand pounds. It is the largest of all living animals; a boat with six persons could enter its jaws. Its tongue is nine feet broad, eighteen feet long, and weighs about eight hundred pounds.

The whale inhabits the northern parts of the Atlantic and Pacific. It has been hunted for the sake of its blubber since the ninth century. A whale forty-eight feet long, and fourteen thousand pounds in weight, will furnish six thousand pounds of blubber, from which four thousand eight hundred pounds of oil will be obtained; there will also be over three thousand pounds of whalebone, which lies in the upper jaw in the place of teeth.

Narwhal, or Sea Unicorn (Monodon monoceros), allied to the dolphins and porpoises. The male has one—almost invariably the left—of the teeth or tusks in the upper jaw extraordinarily developed into a spirally furrowed horn of pure ivory from six to ten feet long. This is the longest tooth found in the Mammalia. The adult animal is from ten to sixteen feet long. It has a grey back, mottled with black, the under parts being much lighter, but also spotted. It has a blunt, short head, no dorsal fin and very small flippers, but is very active and a rapid swimmer. It is peculiar to the Arctic Ocean, though it occasionally strays as far south as the British seas. The oil is valuable and the flesh edible. The ivory is very fine, and in the castle of Rosenborg at Copenhagen is a throne of the kings of Denmark made of this substance.

Porpoise (Phocæna communis).—The porpoise, five, six, or seven feet in length, is common in the North Atlantic. Often off the British coasts a shoal of porpoises may be seen frolicking quite near to the shore. Passengers on board ocean-going liners are always interested in watching the sportive “black pigs,” as sailors call them, race along the side of the ship. The animals are captured chiefly for their oil, and the skin can be converted into useful leather.

Rorqual (Balænoptera musculus).—The common Rorqual is a typical species of the “finners,” as sailors term them; the generic name means “Finned Whale,” in reference to the small back fin that lies near the region of the tail. It attains an enormous size; one caught in the North Sea was ninety-five feet in length, twenty-two feet in width, and weighed over two hundred and fifty tons. Rorquals are the most widely distributed of all the larger Cetaceans; they are found nearly everywhere outside the Antarctic regions.

Whale Fisheries.—With the older method of whale-fishing the chief products were oil and whalebone. Recently the industry has been revolutionized, principally by Norwegians, and practically every part of the animal is used. For the new method a suitable island is selected, a cutting-up station constructed, and all whales killed are towed to the station and there drawn upon land to be dealt with. The modern whaling-vessel is a small and powerful steamer with a heavy harpoon gun mounted in the bows. The harpoon is a special kind of barbed spear. No boats are used, the steamer following the whales when sighted. By dealing with the carcase on shore all parts are now used, including the bone, blubber (or fat), the soft parts after the oil has been expressed being prepared as fertilizers. The flesh is asserted to be palatable and may ultimately be sold for food.