The smallest crab of any is that known as the pinnotheres,[2575] and hence it is peculiarly exposed to danger; its shrewdness, however, is evinced by its concealing itself in the shell of the oyster; and as it grows larger, it removes to those of a larger size.

Crabs, when alarmed, go backwards as swiftly as when moving forwards. They fight with one another like rams, butting at each other with their horns. They have[2576] a mode of curing themselves of the bites of serpents. It is said,[2577] that while the sun is passing through the sign of Cancer, the dead bodies of the crabs, which are lying thrown up on the shore, are transformed into serpents.

To the same class[2578] also belongs the sea-urchin,[2579] which has spines in place of feet;[2580] its mode of moving along is to roll like a ball, hence it is that these animals are often found with their prickles rubbed off. Those among them which have the longest spines of all, are known by the name of echinometræ,[2581] while at the same time their body is the very smallest. They are not all of them of the same glassy colour; in the vicinity of Torone[2582] they are white,[2583] with very short spines. The eggs[2584] of all of them are bitter, and are five in number; the mouth is situate in the middle of the body, and faces the earth.[2585] It is said[2586] that these creatures foreknow the approach of a storm at sea, and that they take up little stones with which they cover[2587] themselves, and so provide a sort of ballast against their volubility, for they are very unwilling by rolling along to wear away their prickles. As soon as seafaring persons observe this, they at once moor their ship with several anchors.

(32.) To the same genus[2588] also belong both land and water[2589] snails, which thrust the body forth from their abode, and extend or contract two horns, as it were. They are without eyes,[2590] and have, therefore, to feel their way, by means of these horns.

(33.) Sea-scallops[2591] are considered to belong to the same class, which also conceal themselves during severe frosts and great heats; the onyches,[2592] too, which shine in the dark like fire, and in the mouth even while being eaten.

CHAP. 52.—VARIOUS KINDS OF SHELL-FISH.

Let us now pass on to the murex[2593] and various kinds of shell-fish, which have a stronger shell, and in which Nature, in her sportive mood, has displayed a great variety—so many are the various hues of their tints, so numerous are their shapes, flat,[2594] concave,[2595] long,[2596] crescent-shaped,[2597] rounded into a globe, cut[2598] through into a semi-globe, arched in the back, smooth, rough, indented, streaked, the upper part spirally wreathed, the edge projecting in a sharp point, the edge wreathed outwards,[2599] or else folding inwards.[2600] And then, too, there are the various distinctions[2601] of rayed shells, long-haired[2602] shells, wavy-haired shells, channelled shells, pectinated shells, imbricated shells, reticulated shells, shells with lines oblique or rectilinear, thick-set shells, expanded shells, tortuous shells, shells the valves of which are united by one small knot, shells which are held together all along one side, shells which are open as if in the very act of applauding,[2603] and shells which wind,[2604] resembling a conch. The fish of this class, known as the shells of Venus,[2605] are able to navigate the surface of the deep, and, presenting to the wind their concave side, catch the breeze, and sail along on the surface of the sea. Scallops are also able to leap[2606] and fly above the surface of the water, and they sometimes employ their shell by way of a bark.

CHAP. 53. (34.)—WHAT NUMEROUS APPLIANCES OF LUXURY ARE FOUND IN THE SEA.

But why mention such trifles as these, when I am sensible that no greater inroads have been made upon our morals, and no more rapid advances have been made by luxury, than those effected through the medium of shell-fish? Of all the elements that exist, the sea is the one that costs the dearest to the belly; seeing that it provides so many kinds of meats, so many dishes, so many exquisite flavours derived from fish, all of which are valued in proportion to the danger undergone by those who have caught them.

(35.) But still, how insignificant is all this when we come to think of our purple, our azure,[2607] and our pearls; it was not enough, forsooth, for the spoils of the sea to be thrust down the gullet—but they must be employed as well to adorn the hands, the ears, the head, the whole body, in fact, and that of the men pretty nearly as much as the women. What has the sea to do with our clothes?[2608] What is there in common between waves and billows and a sheep’s fleece? This one element ought not to receive us, according to ordinary notions, except in a state of nakedness. Let there be ever so strong an alliance between it and the belly, on the score of gluttony, still, what can it possibly have to do with the back? It is not enough, forsooth, that we are fed upon what is acquired by perils, but we must be clothed, too, in a similar way; so true it is, that for all the wants of the body, that which is sought at the expense of human life, is sure to please us the most.