Early on the third day he reached Getina, a considerable village inhabited by Hassaniah Arabs (long since wiped out by the Dervishes). Getina was then a favourite rendezvous of the Nile boats. The flats here were bright with the luxuriant green of sedges which in their abundant growth imparted to the banks the meadow-like character of European river-sides. Thousands of geese (_Chenalopex ægyptiacus_), in no degree disconcerted by the arrival of humans, paced the greensward. Although in places the right bank was bounded by sand-banks thirty feet high, the left appeared completely and interminably flat, and occasionally admitted the culture of sorghum. “This remarkable difference which exists between the aspect of the two banks, and which may be observed for several degrees, is to be explained by a hydrographical law, which is illustrated not only here, but likewise in the district of the Lower Nile. As rivers flow from southerly into more northern latitudes, their fluid particles are set in motion with increased velocity, the result of which is to drive them onwards so as to wash away the eastern bank, leaving a continual deposit on the west.” About two hundred miles to the south of Khartum more signs of Tropical Africa begin to appear. Graceful, shade-giving acacias (_A. spirocarpa_) grew on the river banks, where also were seen great masses of large-leaved shrubs, many of them covered with the beautiful blossoms of the _Ipomœa_ convolvulus. Hippopotamuses were abundant, lions were heard roaring at night, and the semi-Arab, somewhat Nubian population was gradually replaced by the naked, black, and lanky Shiluk Negroes. Great monitor lizards (_Varanus_) and snakes rustled in the dry grass, while _Cercopithecus_ monkeys, crowned cranes, and handsome red and white waterbuck diversified the aspect of the river-banks; huge crocodiles lay on the foreshore. In Negro Nileland Schweinfurth first noticed the ambatch. This is really a member of the bean tribe (_Herminiera elaphroxylon_), which grows in shallow water. Its leaves resemble those of the acacia, and its blossoms are bold, pea-like flowers of bright orange.