Deserts 



But near the real desert, the last shrubs are almost 

 always small scattered acacias which are either the 

 skirmishers or a vanishing rearguard of vegetation. 



In places where man is concerned, vegetation has 

 no chance whatever. The battle is unfair, for his big 

 battalions of goats, sheep, donkeys, camels, and the like 

 are provided with water and are not disturbed by lions 

 and leopards. 



But at least sometimes, under natural conditions, it 

 does not seem at all unlikely that the desert would be 

 encroached upon, and finally occupied by vegetation, 

 which is, as we have tried to show elsewhere, assisted 

 even by its apparent enemies (see p. 198). 



We must mention here, however, one plant, Welwit- 

 schia mirabilis, for it is surely perhaps the strangest and 

 most antiquated of all plants now living on the earth's 

 surface. 



It grows on the stony plateaux of South-West Africa, 

 in one of the worst deserts of the world, but so far as 

 is known only in two places (near Mossamedes and at 

 Haikamchib). Here there are three rainy days in an 

 average year, and the mean annual rainfall is one-third 

 of an inch. But sea-fogs occur almost every night, 

 and with extraordinary punctuality — '^ about midnight 

 ... a gloomy bitter cold mist, which soon enveloped 

 us in total darkness and completely saturated every 

 article of our dress." ^^ A few hours after sunrise there 

 is not a sign of this moisture. Welwitschia has its 

 plateau almost entirely to itself (except for a strange 

 Cucurbit, Acanthosicyos horrida, which has long thorny 

 half-buried stems). 



The Welwitschia consists of a brownish yellow crown, 

 placed fiat on the ground, of ^' shapeless masses of curled 

 and twisted leaf ribands standing out in bold relief from 

 the sharp, glistening dead landscape." It has also long 



179 



