Page:The aquarium - an unveiling of the wonders of the deep sea.djvu/84

Rh to use in describing this structure and its operation, may not convey to my readers the same strong impression of fitness and perfectness 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 adaptation 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 displayed 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 particulars 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 examination, 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 slender 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