548 AisrisruAL report Smithsonian institution, 1917. 



deposited in the park by the department. The zebra-horse hybrid, 

 " Juno," is an especially beautiful animal. This cross was effected 

 by means of artificial impregnation. 



THE HIPPOPOTAMUS. 



Remains of fossil hippopotamuses are found in various parts of 

 Asia and Europe, even in England, but the existing species are con- 

 fined to Africa. In addition to the several geographic races of the 

 common species {Hiypofotamus amyhibius)^ a smaller kind, the 

 pigmy hippo, is known. This latter is confined to western Afi*ica 

 and is very rare in collections. Hippos are essentially aquatic ani- 

 mals and swim with ease. It is said that they remain beneath the 

 surface of the water for so long a time as 10 minutes. On several 

 occasions the introduction of the hippopotamus into the rivers and 

 lakes of the southern United States has been advocated with the ex- 

 pectation that the animal would successfully rid the waters of con- 

 gested aquatic vegetation. In view of the serious depredations upon 

 planters' crops which might well be expected, the advisability of such 

 an experiment is questionable. 



Of the hippos living in the park, the female and older animal was 

 obtained from British East Africa in 1911. She was then about 2 

 years old and weighed 800 pounds. She has grown greatly since 

 her arrival and now weighs about 3,500 pounds. She is gentle and 

 loves attention from her keepers. The male hij)po came from Ger- 

 man East Africa in 1914 and is a much less perfectly tempered ani- 

 mal. He is active and remarkably agile for a beast of his great 

 bulk and can turn and charge with great speed. A young male was 

 bom in the park May 23, 1917. He weighed about 45 pounds and 

 was an expert swimmer at birth. The hippos are quartered in the 

 lion house, where they have access in summer to large outdoor yards 

 and a tank. In winter they are furnished with heated water for 

 their bath and frequently cause great commotion by their vigorous 

 splashing. 



Traveling menageries usually advertise the hippo as the mighty 

 "blood-sweating behemoth." The "blood sweat" is a curious col- 

 ored secretion of the skin. Beddard thinks the description of the 

 " behemoth " of Job much more suggestive of the elephant than of 

 the hippopotamus. 



THE WILD SWINE. 



The wild boar of Europe {8us scrofa) typifies the family of swine. 

 It is presumably the ancestral form of the domestic races. A fine 

 example is shown in a yard near the elephant house. The wart hog 

 of Africa {PJuwochcerus cethiopicus) is famous for his ugly appear- 



