A vast plain, seemingly bounded but by the horizon; treeless, save where a solitary cameel-doorn (Note 1) spreads its feathered leaves, or a clump of arborescent aloes, mingled with rigid-stemmed euphorbias, breaks the continuity of its outline. These types of desert vegetation but proclaim its sterility, which is further evinced by tufts of whiteish withered grass, growing thinly between them.