In addition to the large supplies of oil fat, commerce was indebted to them for the whalebone, formerly so abundant, consisting of broad plates of that black, flexible, horny substance, sometimes measuring eight or ten feet in length; and of these a single individual has been known to furnish eight or nine hundred from each side of the roof of its mouth, as well as upwards of twenty tons of oil. Notwithstanding its colossal size, the Whalebone Whale is very harmless, living principally upon the small animals that crowd the seas to which it resorts, straining them from the surrounding water by means of its sieve-like mouth. THE DOLPHINS. [Illustration: DOLPHIN.] These animals are easily distinguished from the others of the Whale family by their arched forehead, the beak-like jaws, and the beauty and elegance of their movements in the water. For many ages the Dolphin has been noted for its intelligence and docility, its affectionate disposition being quite as noticeable among the water animals, as that of the Dog or the Elephant among quadrupeds. They usually swim in companies, leaping and tumbling over one another with amusing playfulness. They live principally upon Fishes, which, from the swiftness of their movements, they have no difficulty in catching. People have always had a great idea of the strength of the Dolphin, and at one time it was said of those who attempted to perform impossibilities, that they “wanted to tie a Dolphin by the tail.” It is principally with the assistance of this powerful tail that the Dolphin swims with such rapidity, and that it has gained for itself the title of “Sea-arrow.” When the Dolphins—which go in numerous troops and in certain order—meet a ship, they follow it, so as to catch the Fish which the refuse thrown from the ship attracts in quantities. At whatever speed the ship may be, either sailing or steaming, they keep up with it, and play about among the waves, bounding, turning over and over, and never tiring of frisking and tumbling, affording continual amusement to the crew. Many authors have said that the Dolphin leaps high enough above the surface of the water to jump on board small vessels. They say that in this case the animal curves its body round with force, bends its tail like a bow, and then unbends it, in such a manner as to fly like the arrow from a bow. When they saw these animals following their ships, the sailors imagined that they were accompanying them from an instinct of sociability. They have even gone so far as to say that these animals have a sort of affection for seamen, as well as for each other. THE PORPOISES.