f one;
but its rewards are correspondingly greater. The Netherlands by their
struggle have acquired not only territory for an additional half
million population, but have secured to themselves a strategic position
in the maritime trade of the world.

[Sidenote: Mound villages in river flood-plains.]

The abundant fertility of river flood-plains inevitably attracts
population and necessitates some kind of artificial protection against
inundation. The most primitive form of this protection is obvious and
widespread, restricted in neither locality nor race. When the flood
season converts the flat plain of the White Nile below Gondokora (7 deg. N.
Lat.) into an extensive marsh, countless hills of the white ant emerge
over the waters. During the dry season, the ants build up their hills to
about ten feet, and then live in safety in the upper section during the
flood. They greatly surpass in intelligence and constructive ability the
human occupants of the valley, the low and wretched Kytch tribe of the
Dinka Negroes, who like the ants are attracted by the natural vegetation
of the flood-plain, and who use the ant-hills as refuge stations for
themselves and their cattle during the flood.[602] Elsewhere in Africa
the natives are more intelligent, for flood-plain villages built on
artificial mounds have existed from the earliest times. Diodorus Siculus
tells us that those of ancient Egypt, when the Nile was high, looked
like the Cyclades Islands.[603] Similar ones are constructed by the
Barotse tribe on the upper Zambesi.[604] The Niger River, rising in the
Foota Jallon and Kong Mountains which form a region of heavy rainfall
from February to July, inundates a plain of several thousand square
miles for a distance of 250 miles above Timbuctoo. Here again the
villages of the agricultural Song-hoi duplicate those of Egypt, built on
the same clay mounds, wreathed in the same feathery palms, and
communicating with one another only by small boats.[605] The same picture
is presented by the Yangtze Kiang plain during the summer overflow--low
artificial hills rising from the expanse of muddy water and topped with
trees and villages, while sampans moored to their base show the means of
communication.[606] In the broad flood-plain of the lower Mississippi
River, the chronicles of the De Soto expedition state that the Indian
villages visited stood "on mounds made by art." The Yazoo River Indians,
at the commencement of the eighteenth centu