CRUSTACEA. 33 



jaws, but even the horny cuticle and teeth of the stomach, 

 are all cast off along with the shell ; and last of all the 

 tail is extricated. The whole process is not accomplished 

 without long-continued, violent, and painful efforts. Some- 

 times the legs are lacerated, or even torn off in attempting 

 to withdraw them from the shell, and not unfrequently in 

 the younger animal, death follows before, or soon after its 

 accomplishment. Even under the most favorable circum- 

 stances, the denuded animal is left in the most languid and 

 helpless condition, the limbs being so soft and pliant, as by 

 the utmost exertion to be scarcely able to draw the body 

 along. 



79. The flesh is not, however, left entirely without de- 

 fence, for before the old shell is cast away, preparations 

 have commenced for a new one; the membrane sur- 

 rounding the entire animal, and which by the addition 

 of new matter becomes the future shell, having already 

 acquired some density. As soon as the old shell is cast 

 off, this membrane which w r as flabby and wrinkled, be- 

 comes tense by the expansion, or sudden growth of the 

 animal, so that the new shell is much larger than the old 

 one. The process of hardening, and thickening, now pro- 

 ceeds rapidly, and the animal soon acquires the perfect use 

 of its limbs, with the addition of about one fifth of its for- 

 mer weight. 



80. The lobster, like some species of polypi, already de- 

 scribed, when it happens to lose a limb, soon acquires a 

 new one in its place. Possibly the instinct of the animal 

 has taught it this fact, for when caught by one of the 

 claws, it will sometimes by a sudden jerk break the limb 

 off at the first joint, or at its junction with the trunk, at 

 which place it appears that the new limb grows with the 

 greatest facility. 



81. With respect to the growth of the new claw, Reau- 

 mur observed that the wound left by the old one soon 

 becomes covered with a delicate white membrane, with a 

 convex surface. This is gradually pushed forward, be- 

 coming thinner as it is stretched, until it gives way, and 

 exposes the little new claw in the soft state. The new 

 part now enlarges rapidly, and in a few days, acquires a 

 shell as hard as the old one. It however does not attain 



