96 THE OCEAN. 



by a periodica] addition to the interior surface of 

 every plate a little wider in diameter than the one 

 before, thus enlarging the capacity of the aggre- 

 gated plates, together with the enlargement of each 

 plate; and this, as I have already observed, is the 

 mode by which the scales of a fish grow. But from 

 the shape and size of the plates on a Crab or a 

 Lobster, and especially of the great one that en- 

 velops the chest, this mode of growth would not 

 answer the purpose. Another contrivance is re- 

 sorted to, of a character perfectly unique ; one of 

 those contrivances that meet us at every turn in 

 the study of Nature, and that make it so interest- 

 ing and instructive, as manifesting the infinite re- 

 sources of the Mighty God. "When the Crustacean 

 finds that from its increasing size it is bound and 

 pressed by its shelly covering, it retires to some 

 hole or cranny for protection, becomes sickly, and 

 refuses to eat. After pining awhile, the softer 

 parts separate from the inside of the crust, even 

 the muscles becoming detached from the skeleton, 

 and take up a much smaller bulk than before : a 

 thick skin forms over this soft body, replacing the 

 crust, and then the great shield of the chest is 

 thrown off unbroken, and the other plates of the 

 body follow. This seems plain: but it is not so 

 easy to understand how the process is completed. 

 Every one who has looked at a Crab's claw, knows 

 that in a healthv animal it is filled with flesh, that 

 the inside is capacious, but that the joints are very 

 small : now, how is the animal to get its flesh freed 

 from this capacious boot ? One would readily say, 



