IMPOUNDING WATER TO CONTROL BREEDING OF MOSQUITOES. 3 
proceeds from the banks of these streams to either side. The 
deposits from these overflows account for the ridges along the bayous 
and the ancient channels of the river. There is, therefore, a gradual 
fall from these ridges to the lands that lie on either side. These 
lower lands are extensive swamp areas in the basins of which are 
found permanent swamp “lakes” which are extremely shallow. The 
banks of the bayous are formed with a steep declivity toward their 
channels in contrast to the gradual slope toward the swamp areas 
that lie parallel to them. The region is further characterized by 
narrow, crescent-shaped lakes within well-defined banks of the old 
beds of the river, known as “ ox-bows” or “ cut-offs,” formed where 
the action of the river has cut a new channel through the neck of 
one of its many horseshoe bends. The ends of these “ cut-off” lakes 
are usually shallow, showing marshlike conditions, but the main 
body of water is open and comparatively deep. The bayous are 
not connected with these lakes except during periods of high water. 
The swamp lakes tend to drain into the bayous at points lower down 
in the courses of these streams. 
FAVORABLE CONDITIONS FOR MOSQUITO DEVELOPMENT. 
The swamp areas and the channels of the bayous are attended by 
a rank growth of vegetation consequent upon the fertile nature of 
the alluvial deposit and the prevalent moisture which, with the re- 
sulting sediment and vegetable débris, promotes an ideal environ- 
ment for the development of certain species of mosquitoes under 
favorable climatic conditions. The situation becomes increasingly 
emphasized by reason of the imperfect drainage due to the slight 
fall of the land. Among the mosquitoes, Anopheles are found to 
thrive, and the disease which they convey is prevalent among the 
inhabitants of the region. 
LOCATION OF CULTIVATED LANDS, ROADWAYS, AND DWELLINGS. 
In the Delta the timbered lands are practically synonymous with 
the swamp areas. The open lands, or lands under cultivation, are 
confined to comparatively narrow strips along the ridges that form 
the banks of the river, the bayous, and the old courses of these 
streams. These lands are known as the “front” lands and from 
the nature of their deposits are sandy in character. The lands lying 
toward the swamp areas are known as the “back” lands and are a 
heavy clay, impervious to water, called “ buckshot.” 
The roadways of the region follow the higher lands and, wher- 
ever practical, are carried along the bayou banks. The open land 
is cultivated under the negro tenant system, each tenant living upon 
the land assigned to him for cultivation. It is therefore logical to 
find the homes of the tenants on a roadway along the bayou where 
