The Sword-fish (_Xiphias Gladius_) and the Thresher or Sea-fox, a species of shark (_Carcharias Vulpes_), often attack him conjointly and in packs. As soon as his back appears above the water, the threshers, springing several yards into the air, descend with great violence upon the object of their rancour, and inflict upon him the most severe slaps with their long tails, the sound of which resembles the report of distant musketry. The sword-fish, in their turn, attack the distressed whale, stabbing from below; and thus beset on all sides, and bleeding from countless wounds, the huge animal, though dealing the most dreadful blows with its enormous tail, and lashing the crimsoned waters into foam, is obliged to succumb at last. The Greenland Shark (_Squalus borealis_) is also one of the bitterest enemies of the whale, biting and annoying it while living, and feeding on it when dead. It scoops hemispherical pieces out of its body nearly as big as a man's head, and continues scooping and gorging lump after lump, until the whole cavity of its belly is filled. It is so insensible of pain, that, though it has been run through the body, and escaped, yet after a while Scoresby has seen it return to banquet again on the whale at the very spot where it received its wounds. The heart, as is frequently the case with gluttons, bears no proportion to its vast capacity of stomach; for it is very small, and performs only six or eight pulsations in a minute, continuing its beating for some hours after having been taken out of the body. The body also, though separated into any number of parts, gives evidence of life for a similar length of time. It is therefore so difficult to kill, that it is actually unsafe to trust the hand in its mouth though the head be separated from the body. Strange to say, though the whale-fishers frequently slip into the water where sharks abound, Scoresby never heard an instance of their having been attacked by one of these voracious monsters. Perhaps they are loth to attack man, looking upon him as their best purveyor. [Illustration: Saw of the Saw-fish.] Fishermen relate that the whale and saw-fish, whenever they come together, engage in deadly combat; the latter invariably making the attack with inconceivable fury. "The meeting of these champions proud Seems like the bursting thunder cloud." The whale, whose only defence is his tail, endeavours to strike his enemy with it; and a single blow would prove mortal. But the saw-fish, with astonishing agility, shuns the tremendous stroke, bounds into the air, and returns upon his huge adversary, plunging the rugged weapon with which he is furnished into his back. The whale is still more irritated by this wound, which only becomes fatal when it penetrates the fat; and thus pursuing and pursued, striking and stabbing, the engagement only ends with the death of one of the unwieldy combatants.