34 THE NATURAL HISTORY OF THE COMMON CRAYFISH. 



mences, the crayfish rubs its limbs one against the 

 other, and, without changing its place, moves each 

 separately, throws itself on its back, bends its tail, 

 and then stretches it out again, at the same time vibrat- 

 ing its antennas. By these movements, it gives the 

 various parts a little play in their loosened sheaths. 

 After these preparatory steps, the crayfish appears to 

 become distended ; in all probability, in consequence of 

 the commencing retraction of the limbs into the interior 

 of the exoskeleton of the body. In fact, it has been 

 remarked, that if, at this period, the extremity of one of 

 the great claws is broken off, it will be found empty, 

 the contained soft parts being retracted as far as the 

 second joint. The soft membranous part of the exo- 

 skeleton, which connects the hinder end of the carapace 

 with the first ring of the abdomen, gives way, and the 

 body, covered with the new soft integument, protrudes ; 

 its dark brown colour rendering it easily distinguishable 

 from the greenish-brown old integument. 



Having got thus far, the crayfish rests for a while, and 

 then the agitation of the limbs and body recommences. 

 The carapace is forced upwards and forwards by the pro- 

 trusion of the body, and remains attached only in the 

 region of the mouth. The head is next drawn backwards, 

 while the eyes and its other appendages are extracted from 

 their old investment. Next the legs are pulled out, either 

 one at a time, or those of one, or both, sides togethel| 

 Sometimes a limb gives way and is left behind in its sheath. 



