In flood-time a tremendous torrent sweeps down the course of the Atbara, and the sudden bends of the river are hollowed out by the force of the stream to a depth of twenty or thirty feet below the level of the bed.

Accordingly these holes become reservoirs of water when the river is otherwise exhausted.

In such asylums all the usual inhabitants of this large river are crowded together in a comparatively narrow space.

Although these pools vary in size, from only a few hundred yards to a mile in length, they are positively full of life; huge fish, crocodiles of immense size, turtles, and occasionally hippopotami, consort together in close and unwished-for proximity.

The animals of the desert--gazelles, hyenas, and wild asses--are compelled to resort to these crowded drinking-places, occupied by the flocks of the Arabs equally with the timid beasts of the chase.