From here the country changes completely, opening out into a limitless plain, dotted here and there with clumps of borassus palm, growing on small, flat-topped eminences which are the only possible camping-grounds. The channel (which I christened the Gertrude Nile, and which had never hitherto been more than half a mile from the bush) bends away to the west and spreads out into large marshes, though its course is still obvious, and the plain, which is a mass of matted, half-burnt reed, hippo and elephant holes, is scored with numerous channels of water and mud, and towards the bush, which is soon at least fifteen miles from the river, is covered with small ant-hills. There is an enormous population on these plains, with huge herds of cattle and goats, though it is impossible to say where they live, and they are wonderfully clever at hiding their cattle, and light smoke fires to prevent them from making a noise. I marched for hours without seeing a native, but when pitching camp I could see hundreds and hundreds advancing in Indian file from all directions, or if I took a line that led far from water, a group would appear like magic to put me right. There was something uncanny about knowing that one was watched by hundreds without ever seeing more than an occasional individual perched on one leg, the other foot resting on his knee, on the top of a far ant-hill, and looking like a long black stork. The first day that I camped in the plain I was visited by at least a thousand natives.