420 BOTANICAL GAZETTE [MAY 
The meadow formation, as already stated, is narrow and more 
or less interrupted. The soil surface slopes mildly upward, away 
from that of the Swamp meadow. ‘The vegetation is much diversi- 
fied at different places and from month to month during the vege- 
tative season. Poa pratensis and Agrostis alba are the dominant 
grasses, but Danthonia spicata and A gropyron caninum are frequent. 
Scattered among the grasses are Carex stipata, C. vulpinoidea, C. 
scoparia, and Eleocharis palustris. In some parts of the meadow 
Viola cucullata, Senecio aureus, and S. Balsamitae are conspicuous 
in May and June, while later such species as Lilium canadense 
and Rudbeckia hirta are the most noticeable. 
In the entire marsh there were found, exclusive of shrubs and 
trees, 163 species of pteridophytes and spermatophytes. Of these, 
68 were common or even abundant. 
Certain ecological factors 
Four Livingston atmometers were set out May 21, togi1, at 
different stations indicated in fig. 1. Readings were taken weekly 
from May 21 to October 15, and afterward corrected according 
to the method outlined by Livincston (9, p. 273, and 11). A 
detailed account of the evaporation data thus obtained may be 
published subsequently elsewhere, but only the general results will 
be given here. It was found that the average daily evaporation 
at station 1 (in the center of the reed swamp) for the 147 days was 
3 cc.; at station 2 (in the outer part of the reed swamp), 4.5 cc.; 
at station 3 (in the swamp meadow), 4.27 cc.; and at station 4 
(in a stretch of forest running along the east side of the marsh 
and composed chiefly of Quercus bicolor and Fraxinus americana), 
7.91 cc. Thus it will be seen that the evaporation rate was lowest 
in the reed swamp; that the evaporation rates in the reed swamp 
and the swamp meadow were closely similar; and that these rates 
were from about 38 per cent to about 57 per cent as great as the 
rate in a neighboring forest of Quercus bicolor and Fraxinus ameri- 
cana. 
6 The unglazed portion of each cup was placed at a mean height of 2.5 dm. above 
the soil surface. The instruments were not provided with a rain-excluding device, 
such as ‘that recommended by Livincston (10). 
