FLORA AND FAUNA OF BAEKA. 7 Then those of the culminating region reach maturity, so that the first harvest is consumed when the last arrives. Thus for eight months the Cyreneans are always harvesting." * " Red " Barka belongs to the Mediterranean zone of winter rains, although it is also frequently refreshed with autumn showers. Its almost insular position exposes Cyrenaica to all the moisture-bearing winds, except those from the south and south-east ; and the humidity being arrested by the lofty heights, often descends in copious rains. At times the torrents rushing through the mountain gorges down to the coast towns have converted into mud and swept away the hovels, and undermined the more substantial dwellings. Still the yearly rainfall is less than in most European countries, ranging, according to Fischer, from 14 to 20 inches, or from half to two-thirds that of France. From Alexandria to Gyrene it increases gradually westwards. Much, however, of the rain water disappears at once in the fissures of the limestone ground, and is thus lost for the higher lands. But lower down it reappears on the plains, welling up in copious springs at the foot of the cliffs. In many places, and especially in the vicinity of Benghazi, west of the Jebel Akhdar, the subterranean waters would reach the coast through hidden channels, if the ancients had not contrived to arrest their course and bring them to the surface. In spite of the rains which fall on the uplands, Cyrenaica has not a single permanent stream, while *' White " Barka, the region of sands and bare rocks, has nothing but its waterless wadies, and at long intervals a few wells from which oozes a brackish fluid. Flora and Fauna of Barka. The vegetation, being regulated by the quantity of rain water, either received directly from the clouds or filtered through ground in flowing streams, naturally increases in exuberance in the direction from east to west. A careful exploration of the district about the port of Tobruk, in Marmarica, yielded to Schweinfurth not more than two hundred and twenty plants, whereas Ascherson has enumerated as many as four hundred and ninety-three for Western Cyrenaica. The upland region of the plateau, where the rain escapes rapidly through the surface fissures, offers little beyond greyish species, whose scanty foliage is parched by the summer suns. Here and there the monotony of the barren wastes is broken by a stunted acacia or a solitary turpentine- tree. But on all the slopes and in all the depres- sions, where the rain water is retained for any length of time, the laurel, elder, myrtle, mastic, eglantine, and other southern shrubs cluster round the evergreen oak and tall cypress, of freer growth than those of ItrAy, and rising at times to a height of over 160 feet. These dense thickets of trees and shrubs, which never lose their verdure, explain the designation of Jebel Akhdar, the '• Green Hills," applied by the Arabs to the highest uplands of Barka. The forest trees no longer supply much more than fuel ° Book iv., p. 199.
Page:Africa by Élisée Reclus, Volume 2.djvu/23
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NORTH-WEST AFRICA.