58 
IOWA ACADEMY OP SCIENCES. 
shows the greater signs of erosion, because it is exposed to the 
burning rays of the afteruoon sun, while the right bank is in 
shadow during the hottest part of the day. The effect of this 
process upon the distribution of timber is evident. The steep 
bluff -land upon the southern or western bank of a stream is 
usually heavily wooded, while the liat “bottom” upon the 
northern or eastern side is often v^ery sparsely covered with 
trees and sometimes quite bare. Before the advent of civiliza- 
tion the southern bluffs often held the moisture of the winter 
snows and spring rains until after the season of prairie tires, 
thus giving the trees sprouting upon their surface a chance to 
grow, and, when the trees had grown large enough, they fur- 
ther protected themselves from tire, the surrounding grass 
being killed out. But the northern bank, which had to face 
the rays of the spring sun, was well dried by the time the 
grass on the prairie was drj enough to burn, and so the trees 
growing upon its surface were destroyed. This is the process 
which must have taken place during many years before the 
day when the plow of the tirst white settler cut the soil of 
western Iowa. Its effects are still noticeable, but not so 
noticeable as they must have been at an earlier day. To-day, 
practically all of the trees in Adair county are of second 
growth. There are left only a few isolated specimens of the 
so-called first-growth timber. Since the days when the prairie 
fires ceased, seedlings have taken root in the fertile flats 
which form the northern and eastern banks of our streams, and 
have grown into trees of goodly size, atnd in some pla**es the 
southern bluffs have been shorn of their trees. Still, in a gen- 
eral way, the primitive condition is still noticeable; the timber 
on the southern bluff is usually larger and thicker than that on 
the northern bottom. It is noticeable, too, on the prairie — 
wherever enough of the original brush has been left to indicate 
anything at all. The hazel and bur oak will grow on a south- 
ern or western slope, but they are not generally found in such 
a situation. Usually they seek the northeastern side of a hill, 
and there they flourish luxuriantly. 
As has been said, there is very little of the first-growth 
timber remaining in Adair county. The first settlers of the 
county found along the streams a thick growth of large, well 
developed trees. Since then almost all of these trees have 
been removed, until there remains very little timber which was 
well grown at the time of the first settlement of the county, 
