96 THE OCEAN. 
by a periodical 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 frora 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 healthy 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, 
