188 
CLOVER 
wings are forced downward, the anthers 
and stigma emerge, and a little pollen is 
deposited on the under or inner side of the 
head, which may be covered with a layer 
of moist pollen. If a pointed pencil be 
thrust into a mature flower, when it is 
withdrawn a little mass of pollen will be 
found on the other side. As soon as the 
bee moves to another flower the elastic pet¬ 
als cause the anthers to return again with¬ 
in the keel. The collection of pollen is, 
therefore, an incidental result over which 
the bee has no control. While it is visit¬ 
ing white-clover flowers, more or less pol¬ 
len is necessarily rubbed on the under side 
of the head; but a part of it is again 
rubbed off on the stigmas of the flowers 
subsequently visited, effecting cross-pollin¬ 
ation, for the stigma stands slightly in 
advance of the anthers. A part of this 
pollen may also be transferred to the pol¬ 
len-baskets, where it appears as little 
brown balls varying from the size of a shot 
to an almost inappreciable quantity. 
The pollen grains, when examined under 
a high magnifying power, appear oblong, 
cylindrical, rounded at each end, with three 
longitudinal slits or grooves on the sides, 
and the bands or spaces between the slits 
are finely roughened with many shallow 
pits or depressions. A knowledge of the 
form of the pollen is essential in order 
that it may be recognized with certainty 
either in the hive or in the honey. The 
little balls of pollen in the pollen-baskets 
appear brown instead of yellow (the color 
of the pollen in the anthers) because they 
are composed of a moist compact mass of 
grains which have been manipulated by 
the bees’ legs. 
According to Darwin, when insects were 
excluded from white clover by a fine net 
the clover was only one-tenth as produc¬ 
tive as when they were freely admitted. 
THE SECRETION OF NECTAR. 
The factors controlling the secretion of 
nectar by the flowers of white clover are 
very imperfectly understood. In England. 
Canada, and the northeastern portion of 
the United States, it is usually a good 
honey plant, but in France and Switzer¬ 
land one may travel for several kilometers 
and not see a bee on the flowers. At Rouen, 
France, during one day of white clover 
bloom a hive on scales actually lost 300 
grams in weight. In various localities in 
the United States it is also reported to be 
almost a total failure at times. One bee¬ 
keeper says: “As an actual fact, the 
amount of clover honey is not measured by 
the quantity of the bloom; for I have seen 
the fields white with an abundance of it, 
but only a fair crop. I remember one 
year when there was a great scarcity of 
bloom, and yet there was a good crop of 
clover honey. I have also seen fields white 
with clover, but no honey.” At Plainfield, 
N. J., altho the ground is often white with 
the bloom, a good flow is reported to be 
obtained only about once in 10 years. In 
general the secretion of nectar is not reli¬ 
able in sections where the mean annual 
summer temperature exceeds 77 degrees 
F.; but occasionally, if the summer is cool 
and there have been sufficient rains in the 
spring to produce a luxuriant growth, a 
good crop is obtained south of this isother¬ 
mal line. White clover is much more abun¬ 
dant on soils where the underlying rock 
is limestone than on soils derived by the 
disintegration of sandstones and shales. 
On soils rich in lime nectar is secreted 
much more freely than on neutral or acid 
soils. In southern Minnesota, southern 
Wisconsin, and southern Michigan where 
the summers are cool and the soils are of 
limestone origin, white clover seldom fails 
to yield a large surplus; but in Illinois a 
full crop is obtained only about one year 
in three, and in central Kentucky and 
Tennessee only occasionally. In the south¬ 
ern States as in Alabama and Mississippi, 
it is of little importance, as it is neither 
abundant nor a good source of nectar. 
Scholl reports, however, that white clover 
yield's a surplus in northeastern Texas. 
Climate and soil exert a very marked 
effect on the growth of white clover and 
consequently upon the yield of nectar. In 
wet clay ground in regions where the win¬ 
ters are severe, the roots may be much 
broken and drawn out upon the surface, 
or the plants may be killed outright by re¬ 
peated lifting, caused by the alternate 
thawing and freezing of the soil. The de¬ 
structive work of the frost, however, is 
much lessened by the natural mulch af¬ 
forded by the dead vegetation found in 
waste places and in meadows which have 
