1138 
nectar from the rain, by preventing the entrance of drops of water, 
but this is thought to be useless by Miiller on account of the inverted 
position of the flowers, actually causing them to be sought by 
insects as a shelter from rain and dew, and so facilitating their fertili- 
zation by these casual visits. But they would not be useless for 
this purpose in the case of C. aparinoides, whose flowers open 
upward, they being nearly erect on their slender stems. 
There are plenty of guests, bidden or unbidden, in the flowers 
of the Marsh Bellwort. Nearly every one has a goodly number of 
Thrips, (Palgothrips, Sp.), crawling about in various parts of it, 
and busy at something. Sprengel states that they were the only 
insects he had seen in the species of Campanula he mentions, five 
in all including Specu/aria, but he thought that they could hardly 
affect fertilization, and that this must be done by some larger 
insects. Among the insects mentioned by Miiller, nothing is said 
of Thrips. But it seems evident that they may be useful in the 
case of C. aparinoides from a study of the flower and its surround- 
ings. These do not, as already intimated, like species with 
inverted corrollas, offer shelter to the bees and other insects at 
night or during rain. Though the flowers are white or bluish- 
white, they are neither conspicuous nor very accessible, since they 
are usually down among the blades of grass where they most 
delight to grow. Sometimes they stretch upward and offer 
inducements of this kind, which may also be both a cause of 
superior vigor and a result of insect visitation. But the Thrips are 
the only insect visitors I find at allcommon. Others are occasion- 
ally seen, small butterflies and moths and bee-like flies, and they 
not alighting very often. When the Thrips are placed upon a 
slide and examined, they will be seen to be plentifully sprinkled 
with spherical grains of pollen, adhering to various portions of 
their bodies, especially to the antenne and the body-hairs. They 
crawl around in the base of the flowers, and over the style and 
stigmas. They appear too small to go from one flower to another 
to any extent, and especially from one plant to another, though 
this is not impossible, since the plants sometimes grow so closely 
together as to be grasped by the hand and pulled up by the 
handful. But it is not probable that fertilization is effected in 
this manner to any degree. 
