THE HERMIT CRAB. 265 



dition of so essential a part of the hermit's person 

 would be speedily fatal to him, as the sharp pin- 

 cers of his rapacious foes would quickly deprive 

 him of his tail, a part of his body greatly more 

 important to him than the caudal appendage of a 

 terrestrial animal. An instinct, however, is given 

 to this otherwise helpless animal, which com- 

 pensates for the apparent defect in its structure. 

 Exposed to the imminent peril of having the pos- 

 terior part of his body tampered with by the 

 unscrupulous claws of his congeners, he ensures 

 its safety by appropriating some shell suited to 

 his own dimensions, into the spiral chambers of 

 which he extends his unprotected part, and is at 

 once in security, carrying about his abode with 

 him with as much convenience as if it originally 

 formed a part of his organisation. Deserted shells 

 of very small size are suited to the hermit in his 

 juvenile condition ; but, as he increases in bulk, 

 being unable, like the original owner of the 

 house, to increase its dimensions with his own 

 developement, he is obliged to seek a new domi- 

 cile with ampler accommodation ; and at length, 

 on arriving at maturity, he finds it requisite to 

 appropriate the shell of the whelk. It is, how- 

 ever, extremely probable that the hermit does not 

 always content himself with shells which have 

 been abandoned by their true owners, but that he 

 resorts to the most violent proceedings in order 

 to eject the owner and gain possession of his 

 abode. This is rendered almost certain by the 

 perfect freshness of many of the shells in which 



