THE HIPPOPOTAMUS 



INASMUCH as the giraffe belongs to the first family of 

 even-toed ungulates and the hippopotamus belongs to 

 the ninth family, a comparison of the energy organs of 

 these "cousins," with their many contrasting energy 

 characteristics, may throw light upon our theme. 



The hippopotamus is a streamlined animal that has the 

 advantage of not having to bear its own weight in the mud 

 and water that are its habitat, and the giraffe is a land 

 animal that has to support its own weight against gravity. 



The hippopotamus floats in the water during much of his 

 life, spending a relatively small amount of his time foraging 

 on the land. He lives in a tropical swamp amidst luxuriant 

 vegetation, and his bountiful table floats to him. Since his 

 habitat is mud and water, no land animal save man ap- 

 proaches him, and since there is no open water except in the 

 lakes and stretches of the Nile, crocodiles and fish do 

 not share his surroundings, for although the hippopotamus 

 may inhabit the grassy marshes of the lake, he is adapted 

 to the swamp rather than to the water or the land. 



Since the weight of the hippopotamus is usually borne 

 by the buoyancy of the water and the fluid mud, the 

 hippopotamus requires less energy than the giraffe, and, 

 like the rhinoceros and the elephant, has little to fear save 

 man. Even when the hippopotamus moves out of his swamp 

 habitat to forage on the land, he does not need to carry his 

 entire weight, as do land animals, for he establishes runways 

 along the fresh water leading into the swamps and chooses 

 soft soil in which his short legs need only slide him along on 

 his great belly. Often between the footprints of these great 

 beasts may be seen the groove that their huge bulk has 

 rubbed along the ground. So averse is the hippopotamus to 

 stepping over an obstacle that a slight impediment is often 

 sufficient to cause this lethargic animal to change its course. 



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