518 THE FLORA OF THE PRAIRIES. 
settlement. Already there are few localities east of the 
Missouri where their primal simplieity and beauty have not 
already been more or less modified. 
Great changes in the vegetation of a new country neces- 
sarily result from its settlement by an agricultural people, 
but the rapidity and ultimate completeness of the transform- 
ation greatly depend upon the relative susceptibility of the 
country to cultivation. Since vast areas of the prairies 
offer no obstruetions to the revolutionizing plow, the aston- 
ishing rapidity of the change in the flora that follows its 
march can scarcely be conceived by those who have not 
witnessed its actual progress. No sooner is the sod inverted 
than scores of species of the original and most characteristic 
plants almost wholly disappear; in a few years the luxuriant 
wild grasses, overtopped with showy flowers, varying the 
hue of the landscape with the advancing season, have be- 
come supplanted by the cultivated grasses and the cereals, 
and that constant scourge of the agriculturist, the ever intru- 
sive weeds. The timber no longer remains confined to 
narrow belts skirting the streams, for besides the newly-set 
orehards, rapidly growing kinds of trees, planted to afford 
shelter from the fierceness of the summer's sun and the fury 
of the bleak winter winds, everywhere diversify the land- 
scape, while comfortable log cabins, or neatly painted, com- 
modious houses give an air of civilization to districts that 
at no distant period were the undisturbed home of the buf- 
falo and the elk. 
Far more slow has been the change at the eastward, 
where the forests have slowly yielded to the axe of the 
woodman, and where much of the land is too uneven for 
cultivation. Here the forests, though in the longest set- . 
tled districts perhaps once or twice removed, still cover no 
inconsiderable part of the country, and consist, for the most 
part, of the indigenous trees in nearly their original propor- 
tions, while the lesser shrubs and the herbaceous plants they 
primitively sheltered are still persistent, and to a great de- 
