THE crab's hind-feet. 51 



to use in describing this structure and its operation, 

 may not convey to my readers the same strong im- 

 pression of fitness and perfeotness of contrivance, 

 which a glance at the little Crab, when at work, would 

 give ; to myself, it appeared one of the most striking 

 examples I had ever seen of that compensatory adapt- 

 ation of an organ to a requirement, which Paley has 

 so well illustrated. Perhaps I ought to add, that in 

 order to see the structure of the bristles, they must 

 be examined when recent, or preserved in fluid ; for 

 in drying, the hairs fall down and adhere to the side, 

 so as to be undistinguishable. 



But I have not yet done with my little eremite. I 

 the less reluctantly linger on the contrivances dis- 

 played in his economy, because he is so common, and 

 so readily procured, that any of my readers, who may 

 visit a rocky shore at low water, may verify these par- 

 ticulars for themselves. When you first take up one 

 in your fingers, (which, by the way, do with a little 

 caution, for these gentlemen nip pretty hard) one of 

 the most obvious peculiarities is that, besides these 

 flat nippers, you can find only three pairs of legs, 

 instead of four, the complement which Crabs in 

 general rejoice in. You may institute a minute ex- 

 amination, as I did with the first individual that I met 

 with, and yet fail to discover any more ; but there is, 

 notwithstanding, a fourth pair,— very minute indeed, 

 tiny slendei pins, set a little above the general level, 

 and folded down so closely in a groove, beneath the 

 edges of the carapace, as to be almost invisible. 



What is the use of these feeble limbs ? No one 

 that I asked could tell me ; till I asked the Crab 



