CRAWFISH AND LOBSTER. 137 



in this respect again resembling the spider. This process is 

 called moulting, a term used in describing a similar process 

 in the spider. The lobster and crawfish continue to shed 

 their shells at different periods, till they attain full growth. 

 It is stated that the crawfish sheds its shell annually. If the 

 pupils will keep some of these creatures alive, they will prob- 

 ably have an opportunity to observe this curious process of 

 moulting, in which the entire outer skin, or shell, is discarded, 

 so that there is left, complete in all its parts, the empty crust, 

 like a discarded garment. The carapace separates from the 

 abdomen above and cracks along the back, and by a series of 

 efforts the animal pulls its way out. Great trouble is expe- 

 rienced in withdrawing the legs, and oftentimes a leg is left 

 behind, and cases are recorded wherein the animal has perished 

 in the struggles to liberate itself from the old skin. For 

 some time the animal shows great timidity, and the lobster, 

 when it has freshly shed its skin, retires to some secluded 

 place, and there remains till the soft and tender skin has 

 become thickened and hardened, so as to enable it to 

 withstand the attack of its enemies. Lobsters often lose 

 their legs in fighting, and on a sudden alarm are capable of 

 dropping them off. The loss of the leg in this way is made 

 good by the curious property the stump has of reproducing 

 another leg, which grows out again, jointed and shaped like 

 the one lost, only much smaller than the original one. At 

 each succeeding moult, however, the leg becomes larger and 

 larger. If the pupils will now carefully examine a lot of 

 lobsters, they will notice among them some specimens in 



