76 RAMBLESOF 



some hours, but a sort of swelling along the edges 

 of the great upper shell at its back part. After a 

 time, this posterior edge of the shell becomes fairly 

 disengaged, like the lid of a chest, and now the more 

 difficult work of withdrawing the great claws from 

 their cases, which every one recollects to be vastly 

 larger at their extremities and between the joints 

 than the joints themselves. A still greater apparent 

 difficulty presents in the shedding of the sort of 

 tendon which is placed within the muscles. Never- 

 theless, the Author of nature has adapted them to 

 the accomplishment of all this. The disproportion- 

 ate sized claws undergo a peculiar softening, which 

 enables the crab, by a very steadily continued, 

 scarcely perceptible effort, to pull them out of their 

 shells, and the business is completed by the separa- 

 tion of the complex parts about the mouth and eyes. 

 The crab now slips out from the slough, settling near 

 it on the sand. It is now covered by a soft, perfectly 

 flexible skin; and, though possessing precisely the 

 same form as before, seems incapable of the slightest 

 exertion. Notwithstanding that such is its condition, 

 while you are gazing on this helpless creature, it is 

 sinking in the fine loose sand, and in a short time is 

 covered up sufficiently to escape the observation of 

 careless or inexperienced observers. Neither can one 

 say how this is effected, although it occurs under their 

 immediate observation; the motions employed to pro- 

 duce the displacement of the sand are too slight to 

 be appreciated, though it is most probably owing to 

 a gradual lateral motion of the body, by which the 



