He follows the course of the slaver, watching for the horrors of the middle passage, ready to engulf the Negroes’ corpses as they are thrown into the sea. Commerson relates a significant fact bearing on the subject. The corpse of a Negro had been suspended from a yard-arm twenty feet above the level of the sea. A Shark was seen to make many efforts to reach the body, and it finally succeeded in securing it, member by member, undisturbed by the cries of the horror-stricken crew. In order that an animal so large and heavy should be able to throw itself to this height, the muscles of the tail and posterior parts of the body must have an astonishing power. The mouth of the Shark being placed in the lower part of the head, it becomes necessary to turn itself round in the water before it can seize the object which is placed above him. He meets with men bold enough to profit by this conformation, and chase this formidable and ferocious creature. On the African coast the Negroes attack the Shark in his own element, swimming towards him, and seizing the moment when he turns himself to rip him up with a sharp knife. This act of courage and audacity cannot, however, be said to be Shark-fishing. The fishing operation is conducted as follows: Choosing a dark night, a hook is prepared by burying it in a piece of lard and attaching it to a long and solid wire chain. The Shark looks askance at this prey, feels it, then leaves it; he is tempted by withdrawing the bait, when he follows and swallows it gluttonously. He now tries to sink into the water, but, checked by the chain, he struggles and fights. By-and-by he gets exhausted, and the chain is drawn up in such a manner as to raise the head out of the water. Another cord is now thrown out with a running knot or loop, in which the body of the Shark is caught near the tail. Thus bound, the captured Shark is soon lifted on deck, where he is put to death with great precaution as there is still great danger from his bites and the fierce blows of his tail. THE DOG-FISH. [Illustration: DOG-FISH.] The Dog-fish, which sometimes attains the length of between three and four feet, is exceedingly voracious. It feeds upon other fish, of which it destroys great quantities; it does not hesitate to attack the fishermen, and especially bathers in the sea. It places itself in ambush, like the Raias, in order to attack its prey. The flesh of the Dog-fish is hard, smells of musk, and is rarely eaten; but the skin becomes an article of commerce, and is known as shagrin, being, like the skin of the Shark, used for making spectacle-cases and for other ornamental purposes, for which its green color and high polish recommend it. There is a smaller species than the preceding, which haunts rocky shores, where it lies in wait for its prey. Its spots are larger and more scattered, and its ventral fins are nearly square. It feeds on Molluscs, Crustaceans, and small Fishes.