Page:Popular Science Monthly Volume 14.djvu/368

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354
THE POPULAR SCIENCE MONTHLY.

them to die from the effects of exhaustion at the end of the long brooding period. This may perhaps partly result from insufficient nourishment, as they must evidently miss many chances of obtaining food, which others, unburdened with family cares, avail themselves of.

The nearest relations of the octopus are the cuttle-fish and squids. The former, Sepia officinalis, is best known as the animal which produces that fine black-coloring fluid known as sepia-ink, and for its useful sepiostaire or internal shell, which is usually hung in the cages of canary-birds.

Though the cuttle-fish resembles in its general structure its relative the octopus, it varies in several particulars. Instead of eight arms, it has ten, eight short and two long. Some persons have pronounced them "beautiful"—in which opinion we cannot coincide; but their manners are decidedly more genial than those of the octopus. Instead of lurking in semi-concealed caves or behind rocks, and springing upon the unwary like a tiger from its jungle, the cuttle-fish comes out to the light and gives his intended victim a fair chance, having more the habits of a bird of prey than its congener the devil-fish. It is, however, very voracious, and fishermen have often cause to regret its proximity to the fishing-grounds, as it will attack fish while entangled in the nets and drag them out or bite and mutilate them. When attacked, its best defense is the sepia-bag, from which it ejects the black fluid, thus discoloring the water and escaping in the obscurity.

The eggs of the cuttle-fish are usually found attached to a branch of sea-weed and very ingeniously hung by a perfect loop, each one separately upon the twig, where together they somewhat resemble a bunch of grapes. As soon as the young are released, they seek the light and approach the surface of the water. The sepia is naturally very shy, and at the slightest alarm shoots forth with wonderful rapidity its foe-defying ink; but in captivity its fears may be overcome by kindness. It is not difficult to tame, and in time it appears to recognize and appreciate its protector, ceasing to discolor the water when sufficient familiarity has been established between them.

The eyes of the cuttle are so solid as to be almost calcareous, and are divided by a groove in the centre; these halves are nearly globose at their outer surfaces, and reflect light with a "beautiful nacreous opalescence and play of colors." In Italy they are made into beads for necklaces. The cuttle-bone when pounded is used as a polishing powder by jewelers, under the name of "pounce." It is also manufactured into a dentifrice, and sold under the name of "white coral-powder." Artists still use the natural sepia to some extent.

The common squid (Loligo vulgaris) has the same number of arms as the cuttle, but differs in form and some other particulars. The body of the cuttle is of a broad oval shape, with no perceptible neck; the squid is nearly triangular in shape, and has two plainly defined necks, one much smaller inserted within the other and projecting beyond it.