CRUSTACEANS. 143 



From the extraordinary natural disparity of size between the two 

 claws of some species, it would appear doubtful whether they discharge 

 precisely the same functions as where both are more nearly of equal 

 strength and dimensions. 



The Crustaceans generally are carnivorous — testifying the same dis- 

 position which distinguishes other carnivorous animals. They are fierce, 

 cruel, and rapacious, devouring alive such creatures as they can over- 

 power, nor even sparing their own species. The voracity of many is 

 excessive, only ceasing to feed from repletion. Their choice is almost 

 indifferent, provided animal matter can be obtained. This, although 

 half or entu'ely putrid, is not rejected. Some marine vegetables are 

 consumed in periods of famine. 



These creatures are very patient of abstinence. After one copious 

 meal, another within two days is seldom rehshed. 



A few genera confine themselves to terrestrial vegetable products — 

 to macerating wood or leaves exclusively. I have not observed that 

 they were as fierce as the rest. 



The food of many is unknown. Such as survived a considerable 

 time with me in that predicament were returned to then* native abodes, 

 on finding that I could not ascertain what it ought to consist of. 



Some of the Crustaceans are of- a most contentious nature. They 

 are terrible enemies to each other, and the deadly foes of animals weaker 

 than themselves. Hunger renders them bold and ravenous ; and were 

 they proportionally courageous, which is far from the case, the assault 

 of a few of the stronger species on people accidentally sunk in the sea 

 might prevent them from ever rising again. 



But they themselves have many inveterate enemies, as if to balance 

 their insatiable rapacity. Those of the sea, approaching the land, are 

 exposed to a kind of universal persecution ; indeed, some particular 

 species might be included in the list, too large a one, of persecuted ani- 

 mals. 



The most fatal ravages on the Crustaceans are committed by the 

 Actinia, which might be accounted a very insignificant enemy. Se- 

 curely rivetted to the same spot, while numerous stragglers are roused 



