236 WHERE LIVES PRIMITIVE MAN their huge, ungainly bodies. They suddenly awake to the monster coming down on them—a rush, a roll, a plunge, and the water swirls over them. A second later, and a black head rises once more, a fountain of spray may appear as the animal blows, and he makes tracks below the surface once more for his secure hiding-place among the lower stems of the rank green grass, in places where the swamp is wide and provides a retreat impassable for other creatures. Now and again a laugh is raised by the grotesque, pinkish babies recumbent on the halfsubmerged backs of their ungainly mothers.

Perhaps the most interesting period of the day comes in the evening, when the boat is at rest and the fierce light gives way to the deep-toned, fastdarkening twilight. There is a feeling of restlessness everywhere around, for the air is so still and quiet that one hears all the minutiae of sound. Small fish rise, rippling the water, and a slight rustling of bush a distance away betokens some creature prospecting for the evening drink. A flight of teal whistles busily up-river, making a sudden sharp sweep away to avoid the but just perceived boat. The hawks and buzzards have gone to rest, and duck and geese are on the move from feedingplaces to their chosen dormitories. The human watcher lazily speculates, as he hears a murmur arise by degrees into a high-pitched, contumous biz-z-z-z, which will soon drive him to shelter, on their reason for moving, when one place so greatly resembles another.