448 UNGULATES. 



which appears specifically indistinguishable from the living kind was widely spread 

 over Europe, extending from Italy in the south to England in the north. These 

 fossil hippopotami were, however, of considerably larger dimensions than at least 

 the average of the existing race. In England the range of the animal extended as 

 far north as Yorkshire; and it is a remarkable circumstance that in several English 

 localities remains of the hippopotamus are found lying side by side with those of 

 the reindeer. It has been attempted to explain this association of such southern 

 and northern types by assuming that in the Pleistocene period the summers were 

 very hot and the winters very cold, and that during the summer the hippopotami 

 wandered northwards into regions tenanted in winter by the reindeer. There are, 

 however, difficulties in the way of accepting this explanation, not the least being 

 the circumstance that the living African hippopotamus is not a migratory animal. 

 We may, however, be pretty confident that wherever remains of hippopotami are 

 found, there the rivers must have been free from ice throughout at least the greater 

 part of the year. 



The hippopotamus is more essentially an aquatic animal than any 

 other Ungulate, the greater portion of its time being spent in the 

 water, where its movements are far more rapid and natural than they are on land. 

 As the carcase of a hippopotamus when freshly killed sinks rapidly to the bottom, 

 the specific gravity of the animal when the lungs are inflated with air cannot be 

 far, if at all, below that of water, and the animal is consequently enabled to stay 

 without difficulty at the bottom of a river or lake, where it can run with ease and 

 speed. Sir S. Baker states that, when undisturbed, the average duration of time 

 during which a hippopotamus remains under water does not exceed five minutes ; 

 but in regions where these animals are much hunted the length of the immersion 

 is often much greater, sometimes extending to as much as ten minutes. The same 

 writer also mentions that when on the upper Nile in a steamer that was travelling 

 about ten knots an hour, it was not till the engineer increased the pace by putting 

 on full steam, they were able to ovei'take a hippopotamus swimming about a 

 hundred yards in advance of the vessel. When a hippopotamus comes to the 

 surface it generally spouts up a column of water by the violent blowing-out of air 

 through the nostrils, accompanied by a loud snorting noise ; but, as we shall again 

 notice, these animals learn caution in these respects when much persecuted. A 

 peculiarity of the hippopotamus is that when swimming in the water and about to 

 dive, it gradually subsides by slowly sinking the hind-quarters and afterwards the 

 rest of the body, instead of sinking down head- foremost. When on a high bank 

 and suddenly frightened, it will not, however, hesitate to precipitate itself 

 headlong into the water. 



As the giraffe may be regarded as the most characteristic and striking animal 

 in an African desert-landscape, so the hippopotamus forms the most distinctive 

 living feature in a river-scene ; and nothing can be more impressive than to come 

 suddenly upon a herd of these gigantic animals on the margin of some unfrequented 

 lake or river. Such a scene is graphically described by Mr. Selous, who writes 

 that on one occasion his companion and himself, after making their way through a 

 thick bush-jungle, suddenly emerged upon a river-bank. " Upon a spit of white 

 sand which jutted into the pool from the opposite bank, stood, high and dry, a herd 



