306 KEPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 
From all I could ascertain during my short visit to that section I think that by be- 
ginning with cottonwood the elevated ridges and plateaus of this eoteau might ul- 
timately he clothed with timlier, hut tliis is a i|iiestion that must he decided hy the 
horticulturists. If it can he done, anil the settlement of Fastcrn Dakota goes on as 
rapidly as at present, I am thoroughly satisfied that locust visitations to Minnesota 
M ill grow less anil less frequent, and the numbers decrease. In other words, the- bat- 
tle with the- armies of these little foes will he transferred to a great extent to tin- val- 
leys and plains of Eastern Dakota. 
It is therefore to the interest of Minnesota that the settlement of this part of Da- 
kota he pushed forward as rapidly as possible ; that the numerous lines of projected 
railroad through this area he completed at as early a day as possible. Nor will this 
be less beneficial to this portion of Dakota, for the more extensive and more dense the 
settlements become, the less difficult will the contest he. 
But in order to obtain the full benefit of this settlement there are three conditions 
which 1 think it will be necessary to observe. 
First. The clothing of the higher portions of the Coteau of the 1'rairies with timber, 
and I think it would be well for Dakota and Minnesota to apply to Congress for this 
purpose. It is the only assistance in this respect they will have to ask of the govern- 
ment, and whether the result so far as the locusts are concerned be as anticipated or 
not, any reasonable appropriation made for this purpose will not be uselessly spent if the 
work is properly carried out, for the timber will render the land more valuable, and 
it is more than probable that it will have at least a slightly beneficial effect upon the 
climate. It is proper that I should remark, in this connection, that the present Coui- 
missioner of Agriculture, General Le Due, suggested this some two years ago for an- 
other purpose than that now proposed. 
Second. Tree-planting should be carried on as extensively as possible in all the set- 
tlements. 
Third. The lakes, ponds, and even marshes scattered over Western Minnesota and 
Eastern Dakota should be carefully preserved. This is an essential item in the future 
prosperity of this entire region. Drain these or dry thern up, and the day will surely 
come when this entire section and Northern Iowa will he as arid and barren as the 
great plains of the West. Every pond, swamp, or marsh drained is to that extent an 
injury to your State. 
From whence comes the moisture that supplies your prairies ? From the great lakes 
that lie along your northern border from Superior to Winnipeg. Arising from these it 
falls first into or feeds the lakes and marshes of your northern timbered section ; thence 
hy another step it spreads southward over the prairie region, feeding the numerous 
lakes and ponds of that section. The evaporation from these not only assists in draw- 
ing down the moisture which would otherwise be dissipated, but assists in spreading 
it farther southward and southwest. Drain the latter and all this beneficial influence 
will be lost, and step by step the water area will he diminished and the amount of 
rainfall lessened. 
The broad and extensive marshes of the Red River Valley, between Saint Vin- 
cent and Saint Boniface in Manitoba, are of great value to the lands bordering the up- 
per or southern portion of that valley, and if drained will certainly tend to lessen the 
rainfall over the beautiful and productive plains between Red and James Rivers. 
I urge this matter upon your consideration because the history of the world shows 
that in this respect man has generally acted with consummate folly. In all the writ- 
ing and discussions in reference to rainfall and supply of moisture the all important 
item — area of evaporating surfaces — seems to have been overlooked. Preservation of 
forests, planting of trees, &c, have been urged, and properly too, but maintaining or 
enlarging the area of water or evaporating surface seems to have been entirely forgot- 
ten. It is possible perhaps to accomplish this, in part at least, by appropriate State 
legislation. But simply refraining from draining is not sufficient. These little bodies 
of water should be surrounded by fringes of shrubbery and trees which should never 
