CRUSTACEANS. 145 



usually concomitant on death ; the claws are close, and the tail unfolded. 

 Thus, we may conjecture from its representation, what has been the 

 state of the subject when delineated. There are other indications, but 

 unfortunately very seldom denoting animation. They almost invariably 

 prove it extinct. Nay, certain authors of no mean repute have pointed 

 out the most suitable modes of destruction ! 



I do not affirm, however, that the preceding rule is infallible ; that 

 there are no exceptions. I have even seen in two specimens of the same 

 species, the Portunus lividiis, dying in the same vessel, the claws of one 

 closed, of the other open. 



Animals being preserved in museums under the semblance of their 

 natural position, have afforded most of the figures published of the dif- 

 ferent species, which will account for the perpetuation of imperfections. 

 Their genuine representation, however, can be obtained only from vigo- 

 rous living specimens. 



To prevent sudden injury from the vitiated element, if a shell, or 

 other substance some^^iiat elevated above the water, be kept in the vessel, • 

 an isolated specimen may find a temporary retreat on it in safety. 



It is necessary, besides, to be very cautious regarduig the disposition 

 of the different individuals, or the different species associated togetlmr. 

 As some wage perpetual war both against each other and against stranger 

 species, they would defeat the issue of any experiment. If twelve or twenty 

 specimens of the Cancer ma-nas be committed to the same vessel, their 

 numbers daily diminish ; all are killed and devoured by their fellows, 

 until one alone remains victor. Dead or alive they are equally accep- 

 table as food. Therefore, as we shall see, it is prudent, in conducting our 

 observations, to gorge the suljjects abundantly, whereby they are dis- 

 armed. 



But, man is the grand destroyer of all living nature. No animated 

 tenant of the earth or of the waters is safe from his wanton cruelty, 

 whether exercised for pleasure or profit. 



Some of the larger Crustacea, as crabs and lobsters, are eagerly 

 sought after as food, by the inhabitants of Great Britain and other coun- 

 tines ; and, for that purpose, a consideraljle traffic is carried on in both 



