CLIMATE— FLORA— FAUNA. 221 or khnfnh, in which the waters are lost, could hardly be utilised except as a pasture- land. But there are many extensive tracts covered with baobabs, dum palms, tamarinds, and mimosas, whence a gum is obtained known as talc, far inferior to the gums of Kordofan. In Senaar, as in Konlofan and For, on the borders of the regions where water is scarce, the hollow baobab trunks, some of which are 86 feet in circumference, are frequently utilised as natural cisterns. They are filled with water during the rainy season, some of the trunks containing a reserve of some 2,800 to 3,000 cubic feet of water ; the natives climb up and draw off the precious liquid from the tree by means of waterskins. In the northern part of Sudan some of the plains are veritable deserts, the sandhills undulating all around, wearing away the base of the rocks. On the route from Berber to Suakin, Abu-Odfa, an isolated granite block, has thus been eaten away all round its base, and sooner or later the heavy rock will snap its slender pedestal ond fall on the sand. All the cliffs and rocky slopes of this desert region of Upper Nubia are uniformly covered with a kind of blackish varnish, whose origin is unknown. These gloomy walls impart an aspect to the landscape more forbidding and solemn than that of other regions whose mountains are higher and escarpments more abrupt. The forests of the advanced chains, as well as the tall grass of the prairies, in certain spots rising to from 13 to 16 feet after the rainy season, are inhabited by monkeys, lions, leopards, buffaloes, giraffes, rhinoceroses, and elephants. Mostly nomads, the huge pachyderms from one season to another roam over regions of many hundreds of miles in extent. Like the Somali Gadibursi on the other side of the Abyssinian Mountains, the hunters of the Ilamran tribes, in Taka, attack these enormous animals in the boldest manner. Mounted on swift horses they fly before the elephant ; then, suddenly wheeling round, they spring to the ground behind the animal and hamstring it. The huge beast falls on the ground, and the hunter awaits an opportunity to give the second and usually mortal blow. Since 1859, Taka and the conterminous provinces have been regularly visited by hunters, mainly Italians and Germans, not only for the sake of the ivory, consisting usually of tusks much smaller than those of the Central African elephants, but also to capture wild animals for the European menageries. One of these hunters recently brought to the port of Hamburg thirty-three giraffes, ten elephants, eight rhinoceroses, four lions, and several other animals of less value. At the time of the long siege which the Egyptian garrison had to sustain in Eassula, during the years 1884-85, their provisions were drawn largely from parks of wild animals. The Bejas and Abyssinians also hunt the large animals on the borderlands of their respective territories, but when they meet they turn from the pursuit of the quarry and Attack each other as hereditary enemies. The poisonous doboan, or surr^ta fly, swarms in the valley of the Mareb. Its bite, although it does not affect the wild fauna, kills camels, donkeys, oxen, and other domestic animals in a few weeks. Hunting is therefoi-e a dangerous pursuit in these infested regions, where the men have to penetrate on f«x)t into the gorges or high grass. The origin of this fly is unknown ; it may be either the Central African Uet(t^ or the (satza/ia, which Bruce
