28 
IRVING W. BAILEY AND EDMUND W. SINNOTT 
types in tropical and subtropical regions, is also shown in the following 
table. It is in marked contrast to the effects of high alpine or cold, 
dry, upland environments in temperate regions. 
Table II — Tropical or Suh-tr apical 
Lowlands ( io Entire) 
Uplands Entire) 
Trees, 
Shrubs, 
Herbs. 
Trees, 
Shrubs, 
Herbs, 
Percent 
Percent 
Percent 
Percent 
Percent 
Percent 
Hawaii 
84 
71 
67 
70 
50 
24 
Ceylon 
88 
81 
61 
72 
75 
34 
Temperate 
S. New Zealand 
53 
64 
37 
100 
76 
50 
In view of these facts, it is desirable to compare a lowland-tropical 
flora and a uniformly mesophytic cold-tempeiate one. The next 
table gives an analysis of two such floras. The mesophytic cold- 
temperate flora was reconstructed from that of east central North 
America (east of the 95th meridian and between the 40th and 50th 
parallels of latitude) by eliminating all extremely microphyllous 
forms, xerophytes, and plants growing in dry habitats. The lowdand- 
tropical flora was made from that of Brazil, by including the plants 
of the lowlands of the Amazon valley and excluding those from the 
uplands of the southern, central, and eastern provinces. 
Table 
Ill 
Entire fc 
Trees, percent. 
Shrubs, percent. j Herbs, percent. 
Mesophytic Cold-temperate (E. C. N. A.) . . 
10 
14 1 23 
Lowland-tropical. (Brazil) 
90 
87 i 62 
Of course, it should be kept in mind that prevailing climatic in- 
fluences are not absolutely constant throughout these extensive areas. 
Furthermore, it is hardly to be expected that in any such arbitrarily 
selected region of North America there should be an abrupt transition 
from cold-temperate to warm-tempeiate or to arctic conditions. 
It is significant, therefore, that those arborescent species which 
constitute the 10 per cent of entire-leaved plants in the mesophytic 
