504 



CRAB. 



back to the ht'art by a hollow vein (vena cava), of 

 considerable size. 



The process of sloughing, moulting, or throwing 

 off the entire calcareous covering which constitutes 

 their only skeleton, is common to all the crustacea, 

 and is very worthy of attention. As it is obvious 

 Uiat the hard shell, when once perfected, cannot 

 change with the growth of the animal, it becomes 

 necessary that it should be shed entirely; and this 

 shedding takes place at regular periods, at which 

 the increase of size occurs. No one can behold the 

 1 1 uge claws or forceps of various species, and the 

 MU allness of the joints between them and the body, 

 without feeling some surprise that the creature 

 should be able to extricate them from the old shell, 

 though this is readily accomplished. The aquatic 

 crabs, when the season of shedding arrives, generally 

 seek the sandy shores of the creeks and rivers, and, 

 having selected a situation, they remain at rest, and 

 the change begins. The body of the crab seems to 

 swell, the large upper shell is gradually detached at 

 the edge, or where it joins the thorax or corselet, 

 and the membrane gradually gives way, and rises 

 up from behind, somewhat like the lid of a chest. 

 The crab next begins to withdraw the limbs from 

 tlu'ir cases, and the large muscles of the claws 

 undergo a softening, which allows of their being 

 drawn through the smaller joints. This movement 

 is slowly effected, and, at the time it is accomplished, 

 the parts about the mouth, the antenna and eyes 

 are withdrawn from their old cases, and the animal 

 escapes, retaining his original figure,but soft, helpless, 

 and incapable of exertion or resistance. By a gentle 

 and not very obvious motion, we next observe the 

 sand displaced below the body, and the crab be- 

 gins to be covered with it, until, at length, he is suf- 

 ficiently covered for safety, though still in sight. This 

 is generally in shallow water, where the sun shines 

 freely upon the bottom ; and, in the course of twelve 

 hours, the external membrane logins to harden, so 

 as to crackle like paper when pressed upon, and the 

 process of hardening goes on so rapidly, that, by the 

 end of the next forty-eight hours, the crab regains 

 something of his former solidity and ability to protect 

 himself by flight or resistance. Myriads of these 

 animals are caught on the shores of the rivers and 

 creeks of the Chesapeake bay, in America, when in 

 their soft state, and sold to great advantage. At 

 Baltimore, Annapolis, or Easton, in Maryland, in 

 July and August, soft crabs are accounted one of the 

 highest luxuries of the table, and fairly dispute the 

 palm with canvass-back ducks, also to be obtained in 

 perfection in Baltimore during the winter. 



The habits of crabs are very various : some are ex- 

 clusively aquatic, and remain on the sands or rocks, 

 at great depths in the sea ; others inhabit excava- 

 tions formed in the soft coral reefs or bars on certain 

 coasts ; some spend their days altogether on shore, 

 living in burrows or dens, formed in a moist or boggy 

 soil ; others resort to the rocky flats or beaches, to 

 bask in the sun, where only an occasional wave 

 dashes over them, and seek refuge in the sea when 

 alarmed ; while some species are completely terres- 

 trial, inhabiting holes upon the highest hills and 

 mountains of the West Indies. Of these land-crabs, 

 the most remarkable is the species formerly so abun- 

 dant in the highlands of Jamaica (cancer ruricola), 

 and still common in less densely peopled or uninhabit- 

 ed islands. When the season for spawning arrives, 

 vast armies of them set out from the hills, marching 

 in a direct line towards the sea-shore, for the purpose 

 of depositing their eggs in the sand. On this grand 

 expedition, nothing is allowed to turn them from 

 their course. With unyielding perseverance, they 

 surmount every obstacle which may intervene, whe- 



ther a house, rock, or other body, not avoiding tli 

 labour of climbing by going round, but ascending 

 and passing over it in a straight line. Flaving 

 reached the destined limit of their journey, they de- 

 posit their eggs in the sand, anil recommence their 

 toilsome march towards their upland retreats. They 

 set out after nightfall, and steadily advance, until 

 the approach of day-light warns them to seek con- 

 cealment in the inequalities of the ground, or among 

 any kind of rubbish, where they lie ensconced until 

 the stars again invite them to pursue their undeviat- 

 ing course. On their seaward journey, they are in 

 lull vigour and fine condition ; and this is the time 

 when they are caught in great numbers for the table. 

 Their flesh, which is of the purest whiteness, is high- 

 ly esteemed, but like that of all cruslaceous animals, 

 is rather difficult of digestion. Returning from the 

 coast, they are exhausted, poor, and no longer fit 

 for use. They then retire to their burrows, and 

 slough, or shed their shells, after which operation, 

 and while in their soft state, they are again sought 

 by epicures. Seeing they are so much valued as an 

 article of food, it is not surprising that their numbers 

 should be exceedingly diminished, or quite extin- 

 guished, in populous islands, where multitudes are 

 annually consumed, before they have deposited their 

 eggs for the continuance of the species. Besides this 

 cause of diminution, they are destroyed in great num- 

 bers, by other animals, and numbers of them perish 

 from exhaustion and injury on their homeward 

 progress. When the eggs are hatched, the young, in 

 like manner, seek the nuMs, and pursue the course of 

 life peculiar to their race. 



Crabs generally subsist upon animal matter, es- 

 pecially in a state of decomposition, though some of 

 them are very fond of certain vegetable substances. 

 This is especially the case with the swift-running or 

 racer crabs, which live in burrows made in a soft or 

 watery soil, in the vicinity of sugar-cane fields. From 

 their numbers and activity, they become a great nuis- 

 ance, destroying large quantities of cane, by cutting 

 it off and sucking the juice. They sometimes increase 

 to such a degree, that, in conjunction with the rats 

 and other destroyers of the cane, they blight the 

 hopes of the planter, and completely spoil his crop. 

 Their excavations in the soil are so deep and exten- 

 sive, and it is so very difficult to catch or destroy 

 them in any way, that they may be regarded as seri- 

 ously subtracting from the value of estates situated 

 near the sea, or where they are abundant. 



No one, who has not made the experiment, could 

 readily believe the great distance at which these 

 marauders descry an approaching pursuer, nor the ex- 

 traordinary celerity with which they escape. Few men 

 can run with sufficient swiftness to overtake them ; 

 and even when, from any accident, the pursuer is led 

 to hope that he has cut off the retreat of his victim, 

 the wonderful facility they have in running, or rather \ 

 darting in any direction, or with any part of their 

 bodies foremost, almost uniformly enables them to 

 elude capture, and recommence their flight. It is 

 seldom, however, that they leave the mouths of their 

 dens, or go to a distance from them, in the day-time ; 

 and their vigilance is such, that they regain them in 

 a moment, and disappear securely, as soon as a man 

 or dog comes near enough to be seen. The writer 

 of this article has known a planter, whose crop was 

 ruined one season by bad weather, rats, and crabs 

 combined, vent his spleen by shooting the crabs, 

 which were not otherwise to be approached so as to 

 be killed. This, as might be supposed, was a very 

 ineffectual revenge, since their shells are sufficiently 

 hard to cause most of the shot to glance harmlessly 

 off. Perhaps poisoning, by means of the powder of 

 the niuc vowica, or St Ignatius's bean, would prove a 



