254 



WHALES 



/ Blue Whale [looft; ijo tons) weighs as much as. 



4 Br out OS ami 



30 elephants, 



200 cows. 



1600 men or ij cattle trucks. 



a^ 



The trucks shown would collapse, since a 30 ft truck can carry a maximum load of 

 /J to7is. Xiiie such trucks would be needed. 



Figure 131. The weight of a whale. {Slijper, ig^S.) 



surface of their cross-sections, and with increase in total weight a point is 

 reached where the legs would simply collapse under their burden. Hence, 

 once a certain maximum weight is reached, life on land becomes 

 impossible. 



The situation is, of course, quite different in the water, where buoyancy 

 counteracts the gravitational pull on the body. No wonder, then, that there 

 is a great deal of evidence that such giant reptiles as the Brontosaurus, the 

 Diplodocus and the Branchiosaurus, whose weight greatly exceeded the 

 terrestrial maximum, spent practically all their life submerged in rivers 

 or swamps. 



The reader might wonder whether an aquatic environment imposes no 

 limitations whatsoever on an animal's size, and whether, in millions of 

 years to come, animals could evolve compared with which our Blue Whale 

 would be a mere pigmy. While we cannot be certain, we do know that 

 even aquatic animals cannot exceed certain dimensions, because the 

 surface of the lungs, the intestines, the red blood corpuscles and the 

 kidneys become relatively smaller with increase in total weight. Thus, 



