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 flat 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 
