270 ARTICULATA. 



that an operation so critical must often prove fatal, 

 and even those which survive are left in a state of 

 extreme weakness and exhaustion. The limbs are 

 so soft that they may be bent like wet paper ; but 

 the body, perhaps from the tension of the muscles, 

 is remarkably hard. Every part of the surface of 

 the animal is seen to be renewed ; nothing is want- 

 ing in the slough ; the antennae, the jaws, the eyes 

 are here, every hair is a case which enclosed an- 

 other hair ! Even the shelly plates from which the 

 muscles originate, the tendons by which they are 

 inserted into the shell, the internal skin of the 

 stomach, and even the teeth which are hidden there, 

 are found in the rejected shell ! 



The pressure of the old shell being now removed, 

 the animal suddenly increases in bulk, the new skin, 

 as yet soft and flexible, allowing of great expan- 

 sion ; but it rapidly hardens, a stock of shelly mat- 

 ter having been for some time accumulating in its 

 stomach, in the form of two hard balls, commonly 

 called crabs' eyes. This substance is now taken up 

 and distributed to the surface, so that when the 

 new crust has again acquired consistence, the balls 

 are no longer found. This takes place in from one 

 to three days. 



Another interesting faculty conferred upon these 

 animals, is the power of reproducing certain parts 

 of their bodies with all their appendages, after they 

 have been accidentally mutilated. " It appears, from 

 the investigations of Reaumur, that this new growth 

 takes place more readily at particular parts of the 



