20 [ No. 88 GEOGRAPHY .

The crowded Shilluk country (Upper Nile), which is said by some authorities to be the most densely popu lated tract in the whole of Africa , has the appearance of a continuous village . The most sparsely inhabited regions are, of course, the northern deserts. Halfa province has only one inhabitant to 3 square miles, Dongola one to the square mile, Berber and Red Sea 11 , and Kassala 2 .

In the arid north the inhabitants tend to be either nomadic or assembled in towns on or near the Nile.

In the moist and fertile south and on the upper courses of the Abyssinian tributaries they are scattered in villages , which form in the most favourable districts thickly clustered rural colonies.

Towns and Villages Omdurman , the principal native city, which extends for six miles along the left bank of the Nile opposite the Blue Nile confluence, had in 1917 a population of 59,429. Its importance dates from the Dervish period, when , as the residence first of the Mahdi and then of the Khalifa , it grew from a straggling village to a vast collection of native huts . All the principal tribal chiefs have houses or agents there , and it is the head quarters of native trade. Khartum , the administrative capital, is built on the tongue of land formed by the junction of the Blue and White Niles, and has now a large modern quarter, Khartum North, on the right - bank of the Blue Nile . The population of Khartum proper in 1917 was 23,083, and of Khartum North 15,973 . Next in importance are Wad Medani, a flourishing town on the Blue Nile 147 miles above Khartum , with a population of about 15,000, chiefly Fung and Hameg blacks and Arabs ; El Fasher, the capital of Darfur ( reputed population 20,000 ), El Obeid, the capital of Kordofan ( 10,000 ), Suakin ( 10,000 ), El Nahud in Kordofan ( 7,500) , Kosti ( 7–8,000 ), Kassala ( 6,000 ), and Berber town (5,000 ). In the south many of the village settlements shelter a considerable population.