Development of the Vegetation of New York State 161 
have climatic conditions of rainfall, humidity, ete., and soil 
moisture conditions of a degree to justify expectations of 
luxuriant crop yield, whether of forage, grain, fruit, vegeta- 
bles or forests. You might quote my own statements as to the 
wilderness of forest which originally occupied our State and 
in itself constituted proof of the essentially favorable con- 
ditions for plant growth. Using the special terminology 
which botanists employ, it was predominantly a mesophytic 
forest, i. e. 1t reflected not habitual aridity or recurring 
aridity, not swamp or periodically submerged lands and con- 
stantly water-soaked soils, but a constant water reserve in the 
soil from which a maximum vegetation cover could draw its 
daily needs throughout the growing season. In such condi- 
tions one could count on this constant, but not hydrostatic, 
water supply to produce such types of vegetation as a field 
of corn, cabbage, potatoes, wheat and the like. 
Perhaps the space given to the hydrophytic and the meso- 
phytic successions will be justified if it has helped to show 
how largely vegetation itself has been a factor in producing 
mesophytic conditions. You know that whether water 
be in excess or in deficiency in your field soils is very 
often a matter of keeping up the supply of humus. 
You may so reduce this in your sandy soils or the gravelly 
land or on the hill farms that your crops burn up when the 
rain intervals are a bit strung out. On the other hand, the 
same lack of humus replacement may result in epmpact sour, 
and if rain intervals are crowded, in water-soaked soils. In 
other words, the very thing which vegetation tended largely 
to reduce and which intelligent tillage tends to reduce was 
this fluctuation between extremes. I suppose there was hu- 
mus in some of the glacial till carried over from soils of pre- 
glacial or inter- elacial periods, but certainly the lack of it as a 
blanket such as our great forest vegetation had built up when 
explorers first saw it, would leave much of our glaciated ter- 
rain in the situation of the one extreme or the other. Still 
there was a vast amount of glacial till laid down of a kind and 
in situations to favor a constant moisture supply. This would 
