FEATURES OF THE MARCH 51 the way which a river in the flat Sudan country so well knows how to exhibit. So a trek across country is made, and the difference in luxuriance of vegetation is instantly manifest. The bush becomes thinner, and the grass is long and overwhelms everything. Vast areas have already been burnt, and the ash partially hides the multitudinous cracks in the friable "cotton soil," rendering walking difficult and mule-riding a torture owing to continual stumbles.

This soil is one of the peculiarities of the district ; scarcely a square foot of it is without a deep fissure interlacing itself with others, and the islets crumble away under one's weight. In the rainy season it must be almost impassable, and many a time and oft are to be seen the huge pits caused by elephants' feet sinking deep in the course of their meanderings.

Here we took our first long walk, the mule and donkey being led gently some distance behind, ready to stop at an instant's warning on game being sighted. It was early in the morning, and the forest resounded with the voices of birds, almost startling in their strangeness and variety. From one quarter came the shrill, commanding call of a policeman's whistle ; everywhere sounded the word catecherak (Arabic equivalent for " thank you "), repeated with emphasis until the very idea of gratitude became nauseous ; the crows uttered their strange conversation, varying from a bubbling noise to a squawk and a double note in minor thirds, while another whistle resembled an interrogative 4—2