The Sources of Nectar and Pollen 
365 
200 pounds for the bees, and there is rarely enough honey 
from white clover to permit this. This indicates that the 
beekeeper is debtor to the minor sources for much more 
than he is accustomed to believe. 
Gathering of pollen. 
The amount of pollen consumed by a colony annually is 
also considerable. Estimates of the averages in this phase 
of bee feeding are not available, but there is, nevertheless, 
some basis for judging the consumption. If during the 
active season a colony becomes queenless and has no brood 
to feed, the stores of pollen increase rapidly and several 
combs are often filled in a short time. It can scarcely be 
claimed that queenless bees gather more pollen than normal 
ones and, in fact, it is sometimes stated that the gathering 
is then reduced, so that it is safe to conclude that had brood 
been present these extra stores of pollen would have been 
consumed almost as fast as gathered. It must be true, 
therefore, that a colony uses many frames of pollen in a 
season, so that pollen sources are important to the beekeeper. 
In gathering pollen a bee is less uniformly beneficial to 
plants than when gathering nectar. They may cross-polli- 
nate the flowers when so engaged but they are, at the same 
time, appropriating a part of the pollen on which fertiliza¬ 
tion depends. In some species of plants, an abundance of 
pollen seems to serve as an attractive agent, just as does 
nectar in those species provided with nectaries. 
Value of bees in cross-pollination. 
In discussing the plants from which bees gather nectar, ' 
further mention should be made of the beneficial results 
which arise from the visits of bees to the flowers of certain 
fruits. As was explained earlier in this chapter, nectar is 
serviceable to the plant in acting as an attraction to insect 
visitors, which act as agents in cross-pollination. Because 
of the mutual adaptations of the insects and plants, they 
often become mutually indispensable. Some varieties of 
