298 NATURAL THEOLOGY. 



grow bigger by receiving an accretion at their 

 edge ; it is the same with spiral shells at their 

 mouth. The simplicity of their form admits of 

 this. But the lobster's shell being applied to the 

 limbs of the body, as well as to the body itself, 

 allows not of either of the modes of growth which 

 are observed to take place in other shells. Its 

 hardness resists expansion ; and its complexity 

 renders it incapable of increasing its size by addi- 

 tion of substance to its edge. How then was the 

 growth of the lobster to be provided for? Was 

 room to be made for it in the old shell, or was it 

 to be successively fitted with new ones? If a 

 change of shell became necessary, how was the 

 lobster to extricate himself from his present con- 

 finement ? how was he to uncase his buckler, or 

 draw his legs out of his boots ? The process which 

 fisher men have observed to take place is as fol- 

 lows : At certain seasons the shell of the lobster 

 grows soft ; the animal swells its body ; the seams 

 open, and the claws burst at the joints. When 

 the shell has thus become loose upon the body, the 

 animal makes a second effort, and by a tremulous 

 spasmodic motion casts it off. • In this state the 

 liberated but defenceless fish retires into holes in 

 the rock. The released body now suddenly pushes 

 its growth. In about eight-and-forty hours a fresh 

 concretion of humour upon the surface, i. e., a new 

 shell, is formed, adapted in every part to the in- 

 creased dimensions of the animal. This wonder- 

 ful mutation is repeated every year.'^*^ 

 ^See Appendix. 



