484 THE OCEAN WORLD. 



took it with, its claws as it might have taken a biscuit, and set ahout 

 breaking its shell, and so found a way to its flesh. It dug its crooked 

 claws into it with voluptuous enjoyment, appearing to pay no attention 

 to the anger and jealousy of another of its companions, which was still 

 stronger and as cruel, and advanced towards them. But, as Horace 

 says and he was not the first to say it "No one is altogether happy 

 in this lower world ": 



" Nihil est ab omni parte beatum." 



Our ferocious Crustacean quietly continued its repast, when its com- 

 panion seized it exactly as it had seized its prey, broke and tore it in 

 the same fashion, penetrating to its middle, and tearing out its 

 entrails in the same savage manner. In the mean time the victim, 

 singularly enough, did not disturb itself for an instant, but continued 

 to eat the first crab hit hy bit, until it was itself entirely torn to pieces 

 by its own executioner a remarkable instance at once of insensi- 

 bility to pain and of cruel infliction under the lex talionis. To eat 

 and to be eaten seems to be one of the great laws of Nature. 



Though essentially carnivorous, the Crustaceans sometimes eat 

 marine vegetables. Many even seem to prefer fruit to animal food. 

 Such is the robber- crab (Birgus latro) of the Polynesian Isles, which 

 feeds almost exclusively on the cocoa-nut. This crab has thick and 

 strong claws ; the others are comparatively slender and weak. At first 

 glance it seems impossible that it could penetrate a thick cocoa-nut 

 surrounded by a thick bed of fibre and protected by its strong shell ; 

 but M. Liesk has often seen the operation. The crab begins by 

 tearing off the fibre at the extremity where the fruit is, always choosing 

 the right end. When this is removed, it strikes it with its great claws 

 until it has made an opening ; then, by the aid of its slender claws, 

 and by turning itself round, it extracts the whole substance of 

 the nut. 



The Crustaceans have eyes of two kinds simple and compound : 

 the first are sessile and immovable, and very convex ; the other borne 

 on a short calcareous stem or peduncle, and formed of a number of 

 small eyes symmetrically agglomerated the reunion of all the micro- 

 scopic cornea of a composite eye, resembling in shape a cap formed of 

 facets. It is said, for instance, that the eye of the lobster consists 

 of 2500 of these little facets. The simple eyes are mi/opus, or short- 



