90 SECRETS OF EARTH AND SEA 



the animal's food. Ten individuals each weighing a 

 hundredweight will more easily pick up and swallow the 

 amount of food required to nourish ten hundredweight 

 of the species than will one individual responsible for the 

 whole bulk, provided that the food is scattered and . not 

 ready to the mouth in unlimited quantity. A creature 

 which has unlimited forest or grass or seaweed as its 

 food will be at no disadvantage owing to its size. But a 

 carnivor or a fish-eater or one depending on special fruits 

 and roots not offered to him by nature in mass has to 

 search for, and sometimes to hunt, or at any rate to 

 compete with others, for the scattered and elusive " bits " 

 of food. So it is that we find that the fruit-eating apes 

 are not very big, and that terrestrial carnivors are small, 

 though powerful and swift, as compared with cattle, deer, 

 and vegetarian beasts. Ten carnivors weighing each ten 

 stone will with their ten mouths " pick up " more prey 

 than one carnivor weighing a hundred stone and having 

 only one mouth. Even the carnivorous Dinosaurs such 

 as Megalosaurus and Tyrannosaurus were much smaller 

 than the vegetarian Iguanodon, Diplodocus, Brontosaurus 

 and Triceratops on which (or on the like of which) they 

 preyed — ^just as a tiger is smaller than a buffalo, and a 

 wolf smaller than a horse. It is owing to causes of this 

 nature that the life of some animals, and consequently 

 their growth, is limited in duration. Occasionally the 

 common lobster lives to a great age, and grows to be 

 more than 2 ft. long. But he is doomed by his size; the 

 smaller lobsters " go quickly around " and get all the 

 food (carrion of the sea), and the big fellow has to starve. 

 The whale-bone whales, it is, true, take animal food ; but 

 it occurs in the form of minute sea-slugs and shrimps, 

 which fill the surface waters in countless millions over 

 hundreds of miles of ocean. Hence the whales of this 

 kind have only to swim along with their mouths open 



