84 SECRETS OF 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 
Plankton, 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 débris 
—Jjust 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. 
