CRABS AND LOBSTERS. 13! 



not inflict a painful nip with his pincer claws, we shall be able 

 to examine him at leisure. 



The most striking feature of the Great Crab (Cancer pagurus) 

 is its heavy pincer-claws (chela*), which in a really large male, 

 or Jack-crab, assume enormous proportions. I measured a 

 specimen that a few months since found its way to the cooking 

 pot at home. Across the back, measuring the " shell" only, it 

 was ten and a quarter inches long by six and three quarters 

 from back to front. I took no account of the walking feet, but 

 the big chelce measured sixteen and three quarter inches from 

 the root to the tip, and their girth at the thickest part of the 

 "hand" was eight inches and a half. One of these large 

 specimens of the Great Crab always reminds me of a well- 

 baked pie, when I look at him tucking his legs beneath his roof. 

 It is not alone the substance of his shell and the brown tint 

 that suggests pastry, but there are those deep lines in the 

 frontal margin, marking off the " quadrate lobes " of the scien- 

 tific describer, that at once reminds you of the marks the cook 

 impresses upon her paste with a fork. Then, of course, there 

 is the pale undercrust ; and the resemblance will be strength- 

 ened when you observe the voracious Shore Crab, after dining 

 upon a younger brother, holding the empty carapace to his 

 mouth in his pincer-claw, like a piece of pastry, whilst he nib- 

 bles at the edge until it is all gone. 



So much for this fanciful notion; now let us to business. 

 This shell or carapace of the crab has 110 more than the 

 merest superficial resemblance to the shells of oysters or other 

 shelly/*, falsely so-called. Its relationship is much closer to 

 the horny integuments of beetles and other insects. These are 

 formed of a substance called chitin, and of chitin also are all 

 the hard parts of a crab composed, with the addition to it, 

 when in a fluid condition, of calcareous matter, which hardens 

 upon a short exposure to the air or water. Where the limb is 

 to bend the calcareous salts are not-deposited, so we find the 

 joints covered with a membrane of soft chitin alone. 



