CRUSTACEA. 37 



jaws, but even the horny cuticle and teeth of the stom- 

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

 the tail is extricated. The whole process is not accom- 

 plished without long continued, violent, and painful ef- 

 forts. Sometimes 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 circumstances, 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. 



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 was 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 

 proceeds rapidly, and the animal soon acquires the per- 

 fect use of its limbs, with the addition of about one fifth 

 of its former weight. 



The Lobster, like some species of polypi, already de- 

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

 a new one in its place. Possibly the instinct of the ani- 

 mal 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. 



With respect to the growth of the new claw, Reaumur 

 observed that the w 7 ound left by the old one soon be- 

 comes covered by 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 at- 



