Its memory is also considered good. "When once a hippopotamus," says the author just quoted, "has been assailed in its watery dwelling, and injured from incautiously exposing itself, it will rarely be guilty of the same indiscretion a second time; and though its haunts may not again be approached by hunters till after a long period has elapsed, it will survey such approaches, and perform the movements necessary for its respiration with a degree of caution, which clearly shows that it has not forgotten the misfortunes to which an opposite course had exposed it."
The hippopotamus is gregarious, and is usually found in troops of from five or six, to as many as twenty or thirty. It is amusing to watch these animals when congregated; to see them alternately rising and sinking, as if impelled by some invisible agency, in the while snorting most tremendously, and blowing the water in every direction. At others, they will remain perfectly motionless near the surface, with the whole or part of their heads protruding. In this position they look, at a little distance, like so many rocks.
The hippopotamus is a nocturnal animal, and seldom or never feeds except during the night. He usually passes most part of the day in the water, but it is somewhat doubtful if this be not rather from necessity than choice. Indeed, in more secluded localities, one most commonly sees it reclining in some retired spot: "He lieth under the shady trees, in the covert of the reeds and fens. The shady trees cover him with their shadows, the willows of the brook compass him about." Or it may be under shelter of an overhanging dry bank; or, at least, with its body partially out of the water. I have not unfrequently found the animal in this situation, and once shot an immense fellow while fast asleep, with his head resting on the bank of the river.
When, from fear of enemies, the hippopotamus is compelled to remain in the water throughout the day, it takes the shore on the approach of night in order to feed. Just as