6576 Crustacea. 



Although, no doubt, they considerably assist in getting rid of 

 animal refuse from the sea, yet it is all eaten by them before de- 

 composition has commenced; and, therefore, the swimming crabs, 

 no more than other species, have a right to be considered foul feeders. 

 If among Crustacea such are to be found, they exist among the long- 

 tailed genera (Macroura) ; the lobster and the shrimp with their near 

 allies. The fisherman, if he wishes to catch a lobster, baits his trap 

 with stinking meat, but when he hopes to take a crab, he always sets 

 it with fresh ; and we know upon the sea-shore that a drowned dog 

 or cat is soon reduced to a skeleton under the devouring powers of 

 a flock of shrimps. Those who wish to have a skeleton of a bird or 

 other animal perfectly cleaned, will often thrust it into a nest of ants ; 

 but should they find it more convenient, they may procure the same 

 results by mooring it in the sea where a number of shrimps are known 

 to congregate. The knowledge of this fact was made available by 

 the naturalists of the Arctic Expeditions ; they placed specimens, of 

 which they wished to have the skeletons preserved, beneath the ice, 

 where they were rapidly reduced to that state by the myriads of small 

 Crustacea living there. 



These depurators, or swimming crabs, are active, lively creatures 

 that seem conscious of existence, and endeavour to enjoy it to the full 

 extent of their capability. They are called swimming crabs, because 

 they manage to swim a little : they can, by a great deal of kicking 

 with the legs, the two hind ones of which are flattened out to an oar- 

 shape, progress in a diagonal line, but they must crawl up again, and 

 this is called swimming. It puts me in mind of the flight of a 

 young domestic goose, which through a hard day's labour has 

 climbed to the top of a neighbouring hill, will, at sun-down, lift him- 

 self upon the wing and drop, to the astonishment of his old mother, 

 in the valley below ; but not to save his feathers could he perform 

 the feat back again. 



And at the bottom, the so-called swimming crab alights upon his 

 feet, and then he feels at home : ever on his guard, watching, ready 

 to run or quick to attack, as the case may require, to further his own 

 protection ; but it appears that where escape is impossible, and that an 

 enemy is too powerful, the creature will fold his legs together and 

 pretend that he is dead, trusting that where he expected no mercy 

 when alive, he may at least find pity or neglect when dead. This 

 trick is more common with the young edible crabs than any other; 

 they will often throw themselves upon their backs and remain with 

 their legs curled up and motionless for a considerable period, until 



