210 Rhodora [DECEMBER 
or exceeding the styles, and have comparatively large anther cells. 
The length of the calyx is 2.5 mm. 
In the other plant the petals have an average length of 4 mm., while 
the stamens, which are quite inconspicuous, are shorter than the calyx 
or barely equal it, and much shorter than the styles, and the anther 
cells are small. The sepals are about 2.5 mm. long. There are no 
marked differences in the foliage. Later, in Franklin, a typical hill 
town of eastern Connecticut, an Arenaria was found, growing profusely 
in dry open woods, which matches exactly the small-flowered plant 
from Westerly. In wet meadows and open swamps, on the other hand, 
the only form was one with large flowers, which proved to be an equally 
good match for the large-flowered Westerly plant. In one instance, 
in passing from a wet meadow to the surrounding gravel, there was 
an abrupt transition from the large to the small-flowered form, the 
former growing freely in the meadow, and the latter being common 
on the drier gravel, where it was the only form. I soon learned that 
knowledge of local soil conditions enabled me to predict with certainty 
which form would occur at any given station in Franklin. It is not so 
easy to get at the determining factors on the low lands at Westerly. 
On returning there, however, a few weeks later, to secure fruiting speci- 
mens, I discovered that the stations for the large-flowered Arenaria 
were covered with so tall and dense a growth of grasses and sedges 
that it was exceedingly difficult to find the specimens for which I was 
looking, while the places where the small-flowered plant grew, were 
comparatively free from other vegetation, and possess probably a 
drier and more siliceous soil. As already mentioned, the anthers are 
noticeably smaller in the small-flowered Arenaria, and the cells often 
seem to be imperfectly developed. The plant fruits freely, however, 
as, for instance, in dry open woods at Franklin, where there is no ad- 
mixture of the large-flowered Arenaria. Specimens from Westerly 
and Franklin have been deposited in the Gray Herbarium. 
New Haven, CONNECTICUT. 
