CHAPTER XIV 
MESOPHYTE SOCIETIES 
145. General characters. Mesophytes make up the com- 
mon vegetation of temperate regions,, the vegetation most 
commonly met and studied. The conditions of moisture 
are medium, precipitation is in general evenly distributed, 
and the soil is rich in humus. The conditions are not ex- 
treme, and therefore special adaptations, such as are neces- 
sary for xerophyte or hydrophyte conditions, do not appear. 
This may be regarded as the normal plant condition. It 
is certainly the arable condition, and most adapted to the 
plants which men seek to cultivate. When for purposes 
of cultivation xerophyte areas are irrigated, or hydrophyte 
areas are drained, it is simply to bring them into mesophyte 
conditions. 
In looking over a mesophyte area and contrasting it 
with a xerophyte area, one of the first things evident is that 
the former is far richer in leaf forms. It is in the meso- 
phyte conditions that foliage leaves show their remarkable 
diversity. In hydrophyte and xerophyte areas they are apt 
to be more or less monotonous in form. Another contrast 
is found in the dense growth over mesophyte areas, much 
more so than in xerophyte regions, and even more dense 
than in hydrophyte areas. 
Among the mesophyte societies must be included not 
merely the natural ones, but those new societies which 
have been formed under the influence of man, and which 
do not appear among xerophyte and hydrophyte societies. 
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