46 



The National Geographic Magazine 



Factory Children in South Russia 

 " Russia Under the Great Shadow," by L,uigi Villari. James Pott & Co. Copyright. 



THE BLUE CRAB 



FOR rapidity of digestion the hard- 

 shelled or blue crab is probably 

 unsurpassed. The crab disposes of its 

 food so quickly that its stomach is 

 usually found to be perfectly empty 

 within a few minutes after having had 

 a full meal. The common assertion of 

 fishermen, however, that the crab does 

 not retain its food in its stomach at all, 

 has been disproved by dissection, says 

 Mr W. P. Hay in a special study of the 

 life history of the blue crab which has 

 been recently published by the Bureau 

 of Fisheries. A large hardshelled crab 

 if captured and held by one leg will 

 snap the limb off and make its escape. 



The break always occurs at the same 

 point across one of the segments near 

 the base of the leg and is a protection 

 of nature to prevent the animal from 

 bleeding to death. If its leg is injured 

 it will drop it off in the same way. At 

 the first molt after a limb has been cast 

 off 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, ex- 

 cept for its size, looks like the one 

 which was cast off. Another molt, 

 possibly two, will be sufficient to re- 

 store the limb to its full size. Regen- 

 eration of the limbs will not take place 

 more than two or three times. 



