[No. 88 IV . ECONOMIC CONDITIONS (A ) MEANS OF COMMUNICATION ( 1 ) INTERNAL (a ) Roads, Caravan Routes, Paths, and Tracks In the tropical regions of the southernmost portions of the Anglo-Egyptian Sudan communication is confined to a network of native bush -paths and tracks, human porterage being almost the sole means of transport. Over the remaining and far larger area desert conditions prevail, and road communication is effected by means of riding and baggage animals travelling over caravan routes. In certain districts, notably in the provinces of Bahr el-Ghazal, Mongalla, and Kassala, and the southern part of the province of Kordofan, roads have been made and wheeled and motor transport introduced .

The general scheme of road communication in the Sudan is governed by both military and economic considerations, the object being to maintain a well defined system of roads adequately provided with water . Across deserts the routes necessarily lie between wells and water-holes . The following are some of the main cross -country caravan and trade routes: The Darb el-Arbain (i.e. , forty days'road ), between El Fasher (Darfur) and Assiut ( Egypt ), a distance of 1,000 miles . The normal time taken is 32 marching days ( 31 miles a day ), and 8 resting daysspent at the weils and oases . This route passesthrough the natron deposits of Lagia and the oases of Selima and Kharga .