192 VOLUNTARY DISMEMBERMENT. 



intention. He knows that by persevering exertions he 

 can rid himself of his burthen ; and with many violent 

 efforts, and many a weary struggle, he succeeds in 

 getting rid, first of the carapace, or body -shell ; then of 

 the leg-coverings ; then of the tail-piece ; and, finally, 

 of all the shelly coat, down to the coverings of the 

 antennae ; and even the coating of the stomach, with its 

 curious dental apparatus. And the whole is thrown off 

 without loosening the joints or rupturing the shell. It 

 would be impossible for any mounter of specimens to 

 extract the flesh with such nicety, and without injury 

 to any portion of the case. 



The power of voluntary dismemberment possessed by 

 the Star-fishes is shared also by the Crustacea, who will 

 cast away their legs, and even the ponderous claw-bear- 

 ing arms, on being alarmed, or on suffering injury in 

 these members ; and this without the appearance of ex- 

 periencing pain, or more than temporary inconvenience. 

 They walk away, with their remaining limbs, as if 

 nothing particular had happened. After a time the 

 lost portion is gradually restored, the new limb sprout- 

 ing out from the stump of the old. Thus Lobsters and 

 Crabs are frequently met with, one of whose arms is of 

 much greater size than the other, the smaller one being 

 evidently a second growth. 



The general form of the body and the organs of loco- 

 motion are considerably varied in the different families 

 of Crustacea, according to the habits of the animal. In 

 some of the lower races, the body presents a series of 

 rings, or pieces nearly of equal form and size, arranged 

 one after another, and each furnished with a pair of 



