37 
African Park Lands. 
vegetation is an example of a transitional flora , formed upon alluvial 
soil or recent lake-deposits, a flora, that is, which is at the present 
moment colonising soil from which the water has only recently 
receded, and which will in course of time pass over into regular 
forest. 
This solution first presented itself to Mr. Moore during a march 
from the forests of the Upper Semliki valley to the shores of the 
Albert Nyanza. The whole journey was over plains of alluvium and 
lake-deposits which showed that the lake once extended over the 
entire area, but though thick forest covered part of the Semliki 
plains, this gave place northwards to park-lands, while, as the lake 
was approached, the park-lands were gradually replaced by steppe- 
country with very few trees and finally by “ absolutely treeless salt 
wastes bordering the shores.” 
Mr. Aloore’s explanation of this series of phenomena is best 
given in his own words. 
“ By the lake shore there was a belt of reeds, and beyond this 
almost desert steppes over which the fierce tropical sun blazed 
without protection for many hours during during the day. 
The surface of the earth was dessicated and sandy, but a few inches 
below there was an appreciable amount of moisture, due to the 
occasional storms which sweep over such plains and disappear 
almost as quickly as they form. Nothing but grass grew near the 
lake, and even this had evidently had a very bad time, for it was 
scraggy and white and bleached, and alternated with patches of 
absolutely bare sandy soil. On these plains there were, however, 
in places, scattered over the surface of the ground, a few young 
euphorbia trees, the seeds of which had evidently been disseminated 
over the plains by the wind or birds, and as these hardy plants 
grew bigger on the older land further from the lake shore, I noticed 
that in the hot glare of noon their massive structures threw a patch 
of deep cool shadow round their feet Farther away from the lake 
where the land was older and the euphorbias had consequently had 
time to grow proportionately bigger, the noon-day spot of shade 
had also correspondingly increased, and in the area of such shadow 
there were to be found varieties of plants, besides the grass, which 
here found protection from the fiery glare and heat, and were 
consequently able to grow. Among these plants struggling against 
the naturally adverse conditions of the plains under the euphorbia 
shadows there were thorn trees, climbing plants, and flowering 
shrubs, and when once these plants had got a footing on the plains 
they prospered like one of Germany’s protected industries, and 
