LIFE HISTORY OF THE BLUE CRAB. 413 
plete. The crab is now known as a ‘‘soft-shell,” and from the esthetic 
standpoint is at the height of its glory, for all the brilliant coloration 
of the various parts is undimmed by any of the shell deposits, the soft 
integument seeming to bear the bright pigments at the very surface. 
Under natural conditions the crab usually selects some place of con- 
cealment in which to pass the period of shedding and probably does 
not leave it until the new shell has hardened, but it is by no means 
helpless, even immediately after ecdysis has occurred. On the tips of 
legs which seem too soft to support any weight whatever it can walk 
away, or, if forced to make the effort, can swim. The new shell 
hardens quickly. Within twelve hours it becomes parchment-like and 
the crab is called a ‘‘ buckler,” ‘‘buckram,” or a *‘ bucklum;” in two 
or three days it is as hard as ever and once more starts out in search 
of food.4 
AUTOTOMY. 
Autotomy, or the automatic throwing off of the appendages, is very 
characteristically shown in the blue crab and is of frequent occurrence. 
Very often if a large individual, in the hard-shelled condition, is cap- 
tured and held by one leg it will snap the limb off and make its escape. 
Likewise, if one of the legs is injured toward the tip the entire mem- 
ber will be dropped off. The breakage always occurs at the same 
point—across one of the segments near the base of the leg—and is a 
provision of nature to prevent the animal from bleeding to death. It 
is practiced ordinarily only by the hard-shelled crabs; an injury to a 
soft-shelled individual usually causes death. Under other conditions, 
however—notably, a sudden lowering of temperature—the act has been 
observed, and in one of the early attempts to procure soft crabs for 
market, by confining the hard crabs in an inclosure until they had shed 
their shells, severe cold weather reduced the entire catch to a lot of 
legless bodies (‘‘ buffaloes,” they are called by the fishermen). 
Autotomy seems to be limited to the legs, for, so far as I have been 
able to determine, none of the other appendages are ever thrown off, 
although if they are forcibly removed they will be regenerated. 
Regeneration of the parts cast off usually follows autotomy, but, 
according to the researches of several biologists, will not take place 
indefinitely. Three or four times seems to be the limit. The process 
of regeneration is quite rapid. At the first molt after a limb has been 
cast off, provided that the injury does not occur immediately before a 
molt, the new limb appears as a small bud in which all the missing 
segments may be found, coiled in an elongate spiral. At the next 
molt the segments straighten out and the new limb, except for its 
smaller size, looks like the one which was east off. Another molt, 
possibly two, will be sufficient to restore the limb to its full size. 
“Ti is believed by the fishermen that the molting of the crabs is influenced largely 
by the moon and the tides, but the evidence to support this theory is very contra- 
dictory. 
