FOREST TREES. 21 
the diminution can as yet have had but little influ- 
ence upon the climate. 
The early settlers on the Illinois prairies found the 
dry uplands covered with a thick growth of native 
grass, of no great height except when seed stalks were 
thrown up, an occurrence which took place only once 
in two or three years. The scattered woodlands in 
Illinois, called barrens, produced a tall, thin growth 
of grass. On the low, flat prairie lands, the grass, 
mingled with sunflowers and other tall plants, mostly 
with composite flowers, was often from six to ten feet 
high, while the marshes and inundated bottom lands 
produced a coarse, reedy grass of great height. I 
remember riding near the Illinois river where, sitting 
on a horse sixteen hands high, I took the grass from 
each side and tied it together over the top of my hat. 
In a great degree this rank vegetation, covering 
the whole country, compensated in its climatic in- 
fluences for the paucity of forests. The rain falling 
on the surface of the earth, was retarded in passing 
off by the thick grass, and readily absorbed by the 
spongy soil. The rivulets with few exceptions spread 
out in wide beds called sloughs, having no well- 
defined channel, and, clothed with tall grass, slowly 
delivered their waters to the larger streams. The 
porous earth, unshorn of its vegetable growth 
throughout the growing season, yielded its moisture 
more gradually by evaporation than cultivated or 
pastured lands. In dry seasons, the deficiency of 
rain was in some measure supplied by copious dews. 
Rain almost uniformly fell in considerable quantity 
