196 THE HJSTOBY OF ANIMALS. [B. YIH. 



being digested because it ia ligbter than the sea water, tlmt 

 returns to its original nature. That this fluid exists in the 

 sea, and is capable of infiltration is manifest, and may be 

 proved by experiment ; for if anyone will make a thin 

 waxen vessel, and sink it empty in the sea, in a night 

 and a day, it may be taken up full of water, which ia 

 drinkable. 



3. Tlie acalephe (actinia) feeds upon any small fish which 

 may fall in its way. Its mouth is placed in the centre of its 

 body. This organ is conspicuous in the larger individuals : 

 like the oyster, it baa a passage for the exclusion of its food, 

 which is placed above. The acalepbe appears to resemble the 

 internal part of the oyster, and it makes use of the rock, as 

 the oyster does of its shell. (The patella also is free, and 

 wanders about in search of food.) 



4. Among the locomotive testacea, some are carnivorous, 

 and live on small fish, as the purpura, for this creature ia 

 carnivorous, it is therefore caught with a bait of flesh : 

 others live upon marine plants. The marine turtlea 

 live upon shell-fish, for which purpose they have a very 

 powerful mouth ; for if any of them take a stone or any 

 thing else, they break and eat it. This animal leaves the 

 water and eats grass. They often suffer and perish, when 

 they are dried up as they float on the surface, for they are 

 not able to dive readily. 



5. The malacostraca are of the same nature, for they eat 

 everything ; they feed upon stones and mud, seaweeds and 

 dung, as the rock crabs, and are also carnivorous. The spiny 

 lobsters also overcome large fishes, and a kind of retribution 

 awaits them in turn, for the polypus prevails over the lobster, 

 for they are not inconvenienced by the shell of the lobster, 

 so that if the lobsters perceive them in the same net with 

 them, they die from fear. The spiny lobsters overcome the 

 rougers, for their roughness prevents them from falling off&quot;. 

 The congers devoxir the polypi which cannot adhere to them 

 on account of the smoothness of their surface ; all the ma- 

 lacia are carnivorous. 



6. The spiny lobsters also live on small fish, which they hunt 

 for in their holes, for they are produced in such parts of the 

 ea as are rough and stony, and in those places make their 

 habitations; whatever they capture, they bring to their mouth 



