THE DESERT ACACIAS. 423 



in greater or less quantity, by digging to a compara- 

 tively slight depth. The wood of these acacias makes 

 excellent fuel, and some varieties produce a sweet- 

 scented aromatic smoke. The form and appearance of 

 these trees is also always very characteristic, and 

 essentially peculiar to the vegetation of very dry 

 regions, the shape bearing a close resemblance to that 

 of a mushroom. Solymos, a careful and competent 

 observer of these matters, states that "their tops are 

 as sharp cut as if moulded by gardeners into cir- 

 cular disks, flat and level, " and during the surveys for 

 the Soudan Railway he tells us they " rarely accomplish 

 a day's journey without seeing some of them ; and 

 that they are as essentially a characteristic and constant 

 trait in the features of even the most barren and rocky 

 parts of the desert, as the rocks, sands and grasses, 

 and appear beautifully suitable to the landscape, " * all 

 of them are, of course, exceedingly thorny; thorns, or 

 prickles of some kind, being a characteristic of almost 

 the whole of the vegetation of the Desert Zone, and all 

 dry regions even down to the grasses. Evidently as part 

 of a design of Nature for resisting the action of prolonged 

 droughts, the close bushy twigs and foliage of these trees 

 are therefore specially formed to catch and retain every 

 drop of water that may fall from the sky in the rare 

 event of a shower. The moment that the short rainy 

 reason begins therefore (when there is one), these 

 curious little trees at once burst into verdant leafage. 

 On the conclusion of the rains they revert again 

 almost as quickly to their bare, dry, and apparently 

 lifeless condition. The shoots made during a season's 



* Desert Life, by B. Solymos, 1880, p. 64. 



