310 
GRASS OF THE PLAINS. 
Chap. XVII. 
vegetation lias prevented tlie conntry from becoming furrowed by 
many rivulets or “ nullahs.” Were it not so remarkably flat, the 
drainage must have been effected by torrents, even in spite of the 
matted vegetation. 
That these extensive plains are covered with grasses only, and 
the little islands with but scraggy trees, may be accounted for 
by the fact, observable everywhere in this country, that, where 
water stands for any length of time, trees cannot live. The 
want of speedy drainage destroys them, and injures the growth 
of those that are planted on the islands, for they have no depth 
of earth not subjected to the souring influence of the stagnant 
water. The plains of Lobale, to the west of these, are said to 
be much more extensive than any we saw, and their vegetation 
possesses similar peculiarities. When the stagnant rain-w^ater 
has all soaked in, as must happen during the months in which 
there is no rain, travellers are even put to straits for want of 
water. This is stated on native testimony; but I can very well 
believe that level plains, in which neither wells nor gullies are 
met with, may, after the dry season, present the opposite ex¬ 
treme to what we v^^itnessed. Water, however, could always be 
got by digging, a proof of wliich we had on our return when 
brought to a stand on this very plain by severe fever : about 
twelve miles from the Kasai my men dug down a few feet, and 
found an abundant supply; and we saw on one of the islands 
the garden of a man who, in the dry season, had drunk water 
from a well in like manner. Plains like these cannot be inha¬ 
bited while the present system of cultivation lasts. The popu¬ 
lation is not yet so very large as to need them. They find 
garden-ground enough on the gentle slopes at the sides of the 
rivulets, and possess no cattle to eat off the millions of acres 
of fine hay w^e were now wading through. Any one who has 
visited the Cape colony, will understand me when I say that 
these immense crops resemble sown grasses more than the tufty 
vegetation of the south. 
I would here request the particular attention of the reader to 
the phenomena these periodically deluged plains present, be¬ 
cause they have a most important bearing on the physical geo- 
grapliy of a very large portion of this country. The jdains of 
Lobale, to the west of this, give rise to a great many streams, 
