Page:Popular Science Monthly Volume 1.djvu/553

Rh present us with steam shears with blades ten feet long, and intended to receive cavalry—who knows? There is no telling where the ingenuity of modern inventors in the destructive line may lead us. But there are not many instruments so efficient for their purpose as the tooth of a shark. It is difficult to handle one freely without cutting one's fingers; and when we consider the tremendous leverage of a shark's jaws employed against each other like scissors, armed with rows of lancets, it is evident that nothing in the shape of flesh, gristle, or bone, could withstand them. Their capacity, too, is equal to their powers, for a pair of jaws taken from a shark of not more than nine feet long has been known to be passed down over the shoulders and body of a man six feet high without inconvenience. It was thought to be an act of very unusual strength and dexterity on the part of the Emperor Commodus to cut a man in two at one blow, but the jaws of the white shark find no difficulty whatever in executing that feat. The vast number of teeth contained within the shark's jaw has been accounted for by some writers on the hypothesis that they are erected when the shark seizes its prey, at all other times lying flat on their sides. It is now, however, more generally admitted that the shark only employs the outer row of teeth, and that the inner ones are a provision of Nature against an accident which is, and must be, a very common one when the implements are considered, and the force with which they are employed—viz., the breaking of a tooth. In this case the corresponding tooth on the inside becomes erect, and is by degrees pushed forward into the place of the broken one—a wondrous and very necessary provision to keep so delicate and powerful an apparatus as the shark's jaw always in order. The voracity of the shark forms an endless resource for the writers on the marvellous whose bent lies toward natural history. Whole ships' crews have been devoured by sharks ere now, while their omnivorousness is extraordinary. This is well exemplified by the observation once made to me by an old tar, who was dilating on the variety of objects he had found at one time or another inside the bellies of sundry sharks. "Lord love ye, sir," quo' [sic] Ben, "there bain't nothin' as you mightn't expec' to find in the insides o' a shirk, from a street pianny to a milestone!"

Continuing the description of the variety of weapons exemplified in fishes, we have a rival of that terrible scourge the knout in the tail of the Thresher, or Fox-shark (Alopias vulpes). The upper lobe is tremendously elongated, being nearly as long as the body of the fish, and amazingly muscular. It is curved like the blade of a scythe in shape, and the blows which it can and does inflict with this living flail can be