140 BOTANICAL GAZETTE [FEBRUARY 
the last twenty years, until Green is the greatest cheese-producing 
county inthe country. ~ 
The expansion of the cheese interest made it possible for a limited 
rural population to get large returns from a much greater area of hilly 
country than it could till, and has certainly been a large cause of the 
final clearing of the land. At the same time the demands of the neigh- 
boring cities have advanced the price of fuel, and three lines of railroad 
in these four towns built during the eighties gave all parts of them a 
short haul to market. 
The accompanying map shows the native prairie and forest, the 
timber removed during the last fifteen or twenty years and that standing 
now, the water courses and former water courses now dry a large part 
of the year, and most of the former millponds. I have determined, by 
weighing them, the relative areas differentiated on the map, the result 
being : prairie 16.8 per cent., original forest 83.2 per cent., cleared fifteen 
to twenty years ago 55.9 per cent., cleared within fifteen to twenty years 
27-3 per cent., timbered now (September 1902) 5.8 per cent. 
“Fifteen to twenty years ago” is inexact, but it is usually impos: 
sible to tell exactly when a given tract was cleared, and any sharp line is 
therefore impracticable. The time indicated is that at which we became 
personally familiar with the country. It is also difficult, when the trees 
are gradually cut from an area, saw-logs first, cordwood a decade later, the 
young trees later still, or when some more or less abundant kinds are 
spared in the cutting, to decide when it ceases to be fitly mapped as 
timber. We have called any land timbered as long as the heavy shade 
is more continuous than the sod—a loose test, but as good as we 
knew, | 
The map and the figures based on it cannot show the change iD 
the character of what timber remains. The forest was never homo- 
geneous, but in general it was as dense as temperate deciduous forests 
often are. In general there was a considerable mesophytic under- 
growth of thin leaved shrubs and herbs ; more rarely the forest was 
dense enough to keep its floor relatively clear. In either case the ground 
was kept open and loose and the air over it cool and moist. In these 
four towns not a ten-acre grove of such forest is left. The surviving 
timber is pastured and the ground is tramped. The shade-loving; 
shade-making mesophytes disappear and grass gradually comes ine 
The trees become less vigorous and the grass more so. No axe is now 
needed. The grass-covered ground with scant shade is harder and 
smoother than the old forest soil, and dries very much more rapidly: 
