THE CUAYFIHH V-jl 



bility to the shell, which is useful in the act of molting. 

 When the lobster has attained this stage, it is dark in color, and 

 known by fishermen as the " black lobster." The soft cutic- 

 ula now breaks transversely immediately behind the carapace, 

 the blood leaves the limbs, which are thus made flabbier, and 

 by involuntarj^ muscular movements they are drawn, large 

 claw and all, through the joints of the old shell. The anterior 

 portion of the body is first drawn out through the break behind 

 the carapace and, lastly, the tail. Not only is the entire outer 

 covering cast off, but the lining of the esophagus, stomach, anrl 

 intestine as well, since these organs are formed by an infolding of 

 the skin. By means of the return of the blood to the limbs and 

 rapid absorption of water, the body of the lobster soon swells 

 to a size far beyond that of the old shell. There remains 

 in the stomach, after molting, a calcareous nodule which has 

 long been known by the name of " crab's-eye." These " crab's- 

 eyes " were formerly much sought after as " charms " against 

 ill health. Their function was for a long time rather 

 obscure. It is now Ijelieved that during the time of ab- 

 sorption of lime from the shell, previous to molting, the 

 blood becomes strongly impregnated with lime. If all the 

 lime that must be removed were to remain in the blood, 

 it would probably be fatal to the animal ; hence it is taken 

 up by secreting cells located in the wall of the stomach, 

 and there deposited. After the old skin is cast, the gastro- 

 lith is soon absorbed, proliably to aid in strengthening 

 the new shell. Bits of water-worn shells, entire gastropod 

 shells, parts of loI)ster coverings, spines of sea-urchins, etc., 

 have been foimd in the stomachs of lobsters and crayfish, 

 which likewise would probably have been dissolved and used 

 in hardening the shell. 



