Almost the only large white spot now remaining unexplored in the Nile basin is the district occupied by Nilotic Negroes (Dinka, Nuēr, Shiluk), lying between the Sobat River on the northeast and the main White Nile on the west and southwest. This region appears to be a flat country of alternate marsh and arid steppe, producing few or no great rivers of its own. On the west it is watered by the affluents of an important river, vaguely known as the Oguelokur, some of which (such as the Tu and Kos) rise in those high mountains of the Lotuka country in the northernmost parts of the Uganda Protectorate. Mr. Ewart Grogan, accompanied part of the way by Mr. Sharp, in 1899 and 1900, made a remarkable journey, literally from the Cape to Cairo. He travelled from the north end of Lake Tanganyika by way of lakes Kivu and Albert Edward to the Albert Nyanza, and thence down the Nile to the sudd barriers beyond Bor. After which, taking to the land, he traversed the unknown country along that branch of the White Nile called Bahr-az-Ziraf or the Giraffe River. He discovered another branch of the Mountain Nile which joins the Bahr-az-Ziraf, and at the junction of these rivers he notes the entry of a powerful tributary from the southeast, doubtless the Oguelokur. It is sometimes supposed that the southernmost of the Ruzi rivers discovered by Captain Wellby also joins the Oguelokur, and not the Sobat, though the more northern Ruzi may be the head-waters of the Pibor. Some distance to the west of the Pibor is a river called in Sudanese Arabic “Khor Felus.” This river was practically discovered by Captain H. H. Wilson in 1902. Starting southwards from the Sobat, not far from its confluence with the main Nile, Captain Wilson followed the Khor Felus up stream for a distance of some eighty-five miles in a direct line due south. He describes the country traversed by this winding river as being flat and uninteresting,--nothing but a vast grassy plain, with hardly a tree to be seen. The river or khor was not traced to its source, which indeed was said by the natives to be the White Nile itself. If this be true, another branch of the White Nile would start from near Bor and flow northeastwards into the Sobat; further, more natural canals seem to connect the Khor Felus with the Pibor or the Upper Sobat. If this is the case, then in that vast plain lying between the Sobat and the Nile, which was once a portion of the “Lake of Fashoda,” we have still remains of many old channels of the Nile which, as the lake drained off to the northwards, meandered over its drying bed. [Illustration: THE NILE IN EGYPT.] CHAPTER XXVII CONCLUSION