126 UTILIZATION OF MINUTE LIFE. 



Crustacean perhaps of the prawn itself. Be that 

 as it may, the section of Isopoda presents a wide 

 field of experimental research, from the wood-louse, 

 Oniscus murarius, which used to enter into the 

 composition of certain quack pills, upwards. 



Let us now turn to the family of crabs. Our 

 large edible crab (Cancer pagurus, L.) is taken upon 

 the rocky coasts of Great Britain, Ireland, and 

 Western Europe; it is rarely met with on sandy 

 coasts, such as the littoral of Flanders. Pennant 

 says that it casts its shell every year between 

 Christmas and Easter ; but Lyell, in his ' ' Principles 

 of Geology/'' says that a crab taken in April, 1832, 

 on the English coast, had its shell covered with 

 oysters of six years' growth ; hence it was concluded 

 that this crab could not have moulted for six 

 years. 



Like other Crustacea, it is probable that the 

 crab moults once a year in its younger days, but 

 it has not been ascertained at what period this 

 moulting ceases. 



As to artificial breeding and rearing, I shall refer 

 to what has been said of lobsters and crawfish. 



Cancer moenas, L., is a much smaller and less- 

 esteemed edible crab, common on our coasts. A 

 still smaller species is the pea crab (Pinnotheres 

 pisum), which is about the size of a spider; it is 

 found sometimes, in the month of November, living 



