THE CRUSTACEANS. 301 
Another crab, still larger, advanced to the couple so occupied in 
deadly work, and seized the murderer and treated him exactly in 
the same manner as he had his neighbour; first he smashed in his 
carapace and then proceeded to help himself to its fleshy contents ; 
but the curious part of the story is, that his victim was not in 
the least concerned that his body was being eaten, but continued 
enjoying his own repast as though he were in perfect security. 
This was a remarkable instance of their insensibility to pain, as 
well as of the law of retaliation. To eat, and to be eaten oneself, 
is one of the great laws of Nature. “All the marine creatures,” 
says Buffon, “are equally voracious; they live upon themselves 
and upon others; the work of destruction is always in progress— 
and yet no species is ever extinguished, for their fecundity is equal 
to their depredatory propensities, and all the nourishment thus 
gained is expended in reproduction.” The morning following the 
terrible tragedy, only two of the crabs were alive—these were 
the stoutest of the party—and each was squatted in a corner of 
the aquarium, eyeing his rival with defiance. This ferocious 
meditation the naturalist did not interrupt. 
In another instance, four little common crabs were placed in 
the same aquarium. One of them immediately helped himself 
to one of his famished brethren, and a second came to share the 
coveted repast. The poor little crab was with the greatest 
difficulty rescued from his unnatural brothers; and at last, when 
he was delivered from their clutches, it was at the expense of 
seven out of his ten claws; but when put into a separate reser- 
voir he did not seem to bemoan his mutilation, but soon was 
apparently happily devouring a piece of mussel on the floor of 
the aquarium. Ninety-four days after, the little invalid changed 
his carapace and recovered his lost claws; they were less than 
the three he had retained after his encounter, but in all respects 
they were perfect. 
Though essentially carnivorous, the crustaceans sometimes eat 
marine vegetables, especially when in want of food; and there are 
certain of the tribe who appear to prefer fruits to animal matter; 
such, for instance, is the taste of the ¢ree-crab, a native of the 
Polynesian Islands, which lives on the cocoa-nut. This crab is 
provided with strong, thick pincers, its other claws being compara- 
