CRABS. 159 



be stranded at the retreat of the tide. Under such circumstances, if they do 

 not find a hole to take refuge in, they contract their feet, squat down in some 

 corner, and thus await with patience the return of the water. Crab-fishing is 

 usually conducted by two men, in a boat provided with lines and creels, cruives, 

 or crab-pots, as they are variously called, made of a kind of osier basketwork. 

 These are constructed upon the same principle as a wire mouse-trap, but the 

 aperture, instead of being on the side, is at the top. The bait, which consists 

 of stale fish, is fastened to the bottom, and the creel is then sunk in a favour- 

 able situation, by stones of sufficient weight placed within it ; aline is fastened 

 to the creel, to the upper end of which a cork is attached. The bait can readily 

 be seen by the crabs, which entering, are caught like rats in a trap; the diffi- 

 culty of egress being increased by the aperture being overhead. 



FIG. 162. TMIXD STAGE OF SHORE CRAB. 



Crabs undergo a remarkable metamorphosis. On leaving the egg, their larva? 

 have a very grotesque appearance. They are furnished with a large helmet- 

 shaped head, ending behind in a long point, and provided in front with two 

 monstrous sessile eyes, like the windows of a lantern. By means of a long 

 articulated tail, the little creatures continually turn head-over-heels. Claws 

 are as yet wanting, and the young crab has only four pairs of legs, armed with 

 long bristles, that push food towards the ciliated and ever-active mouth. 

 Immediately after casting its first skin, the body makes an approach to its 

 future permanent form, the eyes become raised on stalks, the claws and feet 

 begin to make their appearance, but the tail still remains like that of a lobster, 

 and is used by the young crab to swim about merrily in the water. It is not 

 until the next moult, when the little creature measures about one-eighth of an 

 inch in diameter, that the mature form is completely developed. The facility 

 with which these Crustaceans cast off their legs, and even their heavy claws, 

 when they have been wounded, is a most remarkable feature in their economy. 

 Without the least appearance of pain, they continue to run about upon their 

 remaining legs, and, wonderful to relate, after some time a new limb grows out 

 of the old stump, and takes the place of the original member. When the old 

 claw is separated, a scar forms, and remains until the animal casts its shell. 

 After the shell is thus cast, a protuberance in the centre of the scar suddenly 

 enlarges, and under it may be seen a small claw, doubled on itself beneath the 

 membrane of the stump. This remains in a soft state until the crab again 

 casts its shell, when the new claw is set at liberty, straightened out, and be- 

 comes hard and calcareous, like other parts of the body. 



The Rider or Racer Crabs (Ocypoda)* found on the coasts of Syria 



* WKVS, okys, swift; TTOI/S, TroSos, pous, podos, afoot. 



