86 ANIMALS OF THE PAST 



say that it would not be far from 25 tons, and that one 

 would devour at the very least something over 700 

 pounds of leaves or twigs or plants each day more, if 

 the animal felt really hungry. 



But here we must, even if reluctantly, curb our imagi- 

 nation a little and consider another point: the cold- 

 blooded, sluggish reptiles, as we know them to-day, do 

 not waste their energies in rapid movements, or in 

 keeping the temperature of their bodies above that of 

 the air, and so by no means require the amount of food 

 needed by more active, warm-blooded animals. Alli- 

 gators, turtles, and snakes will go for weeks, even 

 months, without food, and while this applies more 

 particularly to those that dwell in temperate climes and 

 during their winter hibernation practically suspend the 

 functions of digestion and respiration, it is more or less 

 true of all reptiles. And as there is little reason for 

 supposing that reptiles behaved in the past very differ- 

 ently from what they do in the present, these great 

 Dinosaurs may, after all, not have been gifted with 

 such ravenous appetites as one might fancy. Still, 

 it is dangerous to lay down any hard and fast laws con- 

 cerning animals, and he who writes about them is con- 

 tinually obliged to qualify his remarks in sporting 

 parlance, to hedge a little, and in the present instance 

 there is some reason, based on the arrangement of verte- 

 brae and ribs, to suppose that the lungs of Dinosaurs 

 were somewhat like those of birds, and that, as a corol- 

 lary, their blood may have been better ae'rated and 

 warmer than that of living reptiles. But, to return to 

 the question of food. 



From the peculiar character of the articulations of 

 the limb-bones, it is inferred that these animals were 

 largely aquatic in their habits, and fed on some abun- 

 dant species of water-plants. One can readily see the 



