84 SECRETS OP ANIMAL LIFE 



organisms as have stolen their secret of photo- 

 synthesis. But it is time to add the statement 

 that a large proportion of the animals of the sea- 

 floor live on dead detritus, which is formed by 

 contributions from three sources the superficial 

 Planktpn, the fauna and flora of the shore, and 

 what is borne down by rivers. We shall return to 

 this in our next study. 



The natural consumers of the wealth of the sea 

 are the animals, but these are not all on the same 

 platform. First, there are true carnivores, like 

 most fishes, all cuttlefishes, many Gasteropods 

 (like whelks), many crabs, most starfishes, and so 

 on down to sea-anemones. Second, there are 

 vegetarians, like periwinkles and limpets, on the 

 shore, and some of the open-sea animals like the 

 Copepod Crustaceans. Third, there is an enormous 

 multitude depending mainly on crumbs or detritus. 

 This classification is not, of course, to be taken too 

 rigidly, for it will be readily understood that many 

 a marine carnivore may also utilize carneous debris 

 just as a Golden Eagle, with a preference for 

 fresh grouse, does not always hold carrion in dis- 

 dain. Similarly, some marine vegetarians are not 

 too scrupulous as to the constituents of the sea-soup 

 they enjoy. The probability is that the distinction 

 between carnivore and vegetarian is not so important 

 as that between animals with and animals without 

 hard prehensile and chewing mouth-parts. This, like 

 Professor William James's division of mankind into 

 tough-minded and tender-minded, goes very deep. 



