326 THE LIVING ANIMALS OF THE WORLD 



may seem when viewed from behind 

 the bars of its den in a zoological 

 garden, it is nevertheless true that, 

 when these animals have been 

 banished from an African river by 

 the progress of civilisation, that river 

 has lost one of its highest charms 

 and greatest ornaments. 



The PYGMY or LIBERIAX HIP- 

 POPOTAMUS is confined to Upper 

 Guinea, and, compared with its only 

 existing relative, is a very small ani- 

 mal, not standing more than 2 feet 

 6 inches in height, and measuring 

 less than 6 feet in length. In weight 

 a full-grown specimen will scale about 

 400 Ibs. But little is known of 

 the habits of this rare animal, speci- 

 mens of which, I believe, have never 

 been obtained, except by the German 

 naturalists Herrn Biittikofer and 

 Jentink. When alive, the colour of 

 ph,t/> ty r,rk &> s n j iNotting ma th e skin of the pygmy hippopotamus 



MALE AND FEMALE HIPPOPOTAMUSES is said to be of a greenish black, 



c , changing on the under-parts to 



A hippopotamus is almost inseparable Jrom the water , it never goes Jarther away 



than possible from a river or lake yellowish green. The Surface of the 



skin is very shiny. This species, 



unlike its giant relative, does not congregate in herds, nor pass its days in rivers or lakes, but 

 lives in pairs in marshes or shady forests. It sleeps during the day, and at night wanders 

 over a great extent of country, eating grass, wild fruits, and the young shoots of trees. Its 

 flesh is said to be very succulent and much esteemed by the natives. 



A hippopotamus, apparently of the same species as that now found in Africa, formerly 

 inhabited the Thames Valley. Great quantities of fossil remains of another species are also 

 found in the island of Sicily. The bones found in England are mainly in the river gravel 

 and brick earth of the south and midland districts of England. This seems to show that at 

 the time when the animal existed our rivers must have been open all the year, and not 

 ice-bound, for it is certain that no hippopotamus could live in a river which froze in winter. 

 Yet among the remains of these animals are also found those of quite arctic species like the 

 Musk-ox and the Reindeer, together with those of the Saiga Antelope, an inhabitant of the 

 cold plateau of Tibet. The problem is : How could these creatures, one a dweller in warm 

 rivers and the others inhabitants of cold arctic or sub-arctic regions, have existed together, 

 apparently on the same area of ground? The answer, which does not seem to have occurred 

 to naturalists who have discussed the question, seems to be plain enough. Any one who 

 knows the conditions of the great rift valleys of Central Africa has the key to the solution 

 of the puzzle. There was probably a very great difference in the vertical plane. Deep in 

 the rift was probably a warm river, while above it may have been mountains from 10,000 

 to 20,000 feet high, with snow on the summits and glaciers in their valleys. On these cold 

 and arctic heights the reindeer and the musk-ox would find congenial homes. Thousands 

 of feet below, in the hot and narrow valley, the hippopotamus would revel in a warm and 

 steamy climate. This is what actually occurs in the rift valleys of Central Africa, where 

 the hippopotamus swims in rivers that are at no great distance from snow-covered and ice- 

 capped mountains. 



