38 NATURE-STUDY REVIEW [16:1— Jan., 1920 



then we must forgive the poor beast, for it behaves so only in self 

 defense. 



When resting the llamas make a peculiar humming noise, which 

 when coming from a large flock in the distance is said to resemble 

 the musical humming of a number of aeolian harps sounding in 

 concert. It must be a lovely sound on a summer evening among 

 the high mountain peaks ! 



THE Hippopotamus 



The Hippopotamus, or River Horse, which inhabits the lakes 

 and rivers of central and southern Africa, is one of the bulkiest 

 of all land animals, being exceeded in weight only by the elephant, 

 and occasionally by the rhinoceros. It often attains the weight of 

 three or four tons, and a length of eleven or more feet, yet it stands 

 only about five feet high. Its legs, though massive, are very short, 

 and give the creatiure an awkward, dimipy appearance. 



Hippopotami live in herds of from five to fifty individuals. 

 Dtu*ing the daytime they are seldom seen out of water, but spend 

 their time dozing in the deep pools with only their eyes, ears, and 

 nostrils above the surface. With all their bulk they are neverthe- 

 less, rather sportive creatiu*es, and can often be seen frolicking 

 like huge porpoises, or feeding upon the water plants along the 

 margins of the streams. They frequently come out of the water 

 when the sun is hot, and bask in its warm rays, or wallow in the 

 mud, like so many enormous pigs. This habit, together with the 

 grunting noise which they make when playing, or when alarmed, 

 reminds us that they belong to the same great order of animals 

 as the pig. Indeed they are often called river pigs. At dusk 

 they come out of the rivers to feed, and often walk long distances 

 overland in search of good feeding grounds. They are very 

 destructive to crops, for they eat immense quantities of food, one 

 often consimiing as much as six bushels of vegetable matter. They 

 trample down much more than they eat. In going to and from 

 their feeding grounds they make regular paths through the grasses, 

 and it is in these paths that the natives set their traps. We may 

 well wonder what sort of useful purpose such animals serve. 

 One writer says : ' ' The chief office of the Hippopotamus is to keep 

 in check the dense vegetation in the tropical climates, which, if 

 allowed to accumulate, would block up the long reaches of rivers, 

 and ultimately turn the flat lands into useless fever-breeding 



