VOL. XLIV.] PHILOSOPHICAL TRANSACTIONS. 205 



It is really amazing and inconceivable, by what power or contrivance in itself, 

 so wonderful an operation can be performed by the crab, as voluntarily to crack 

 and break so hard a shell, and its muscles, and then cast off its legs. The 

 small diameter of this joint, the disposition of the fibres, and a very small cir- 

 cular fossa, may contribute greatly to accelerate the work; but yet the main 

 spring of action seems beyond the reach of human comprehension. The whole 

 performance is so curious, and so singular a fact in the history of nature, that it 

 may well deserve a nicer consideration, by those that have greater abilities, and 

 more leisure, for such inquiries. 



When the leg is dropped off, a mucus or jelly is discharged on the remaining 

 part of the joint next the body, which, as a natural styptic, instantly stops the 

 bleeding, and gradually hardens and grows callous, and forms into a leg in mi- 

 niature, which by degrees shoots forth, and attains to its natural size, to supply 

 the place of that which was lost. 



An experiment was next tried, to see of what great service the mucus or jelly 

 was to the crab. When its legs were all cast off, the ends of 2 or 3 of the 

 stumps were pierced with a pointed iron, so as to break off the jelly that stopped 

 them ; on which signs of more intense pain were exhibited, a very large flux of 

 blood ensued, and the creature soon died in great agonies, as was manifest by a 

 tremor of those parts about the mouth, and a frothing like that which attends 

 epileptic fits. 



The crabs are naturally very quarrelsome, and with their great legs or claws 

 fight and kill each other : with them they catch hold of their adversary's legs, and 

 whatever they seize, they strongly retain for a long while : there is no escaping 

 their cruel foe, but by voluntarily leaving a part of the leg behind, in token of 

 victory, but the principal end for which this is done, is the saving the life of the 

 conquered ; for when they are bitten and bruised, and cannot break off that limb, 

 they soon bleed to death. 



The fishermen showed an experiment, to give some idea of the tenacious dis- 

 position of this creature, by obliging a crab with its great claw to lay hold of a 

 small one : the silly creature did not distinguish that itself was the aggressor ; but 

 exerted its strength, and soon cracked the shell of its own small leg, and it bled 

 freely ; but feeling itself wounded, to save its life required a power peculiar to it- 

 self to break off that limb in the usual place ; which it presently effected, and 

 held fast for a long time the broken part in his great claw : which evidently shows, 

 that this creature retains whatever it lays hold on, and when overcome by its 

 enemy, ransoms its life at the expence of a limb. 



