FERTILISATION AND POLLINATION 63 
pulls down the “keel.” The result of this is that some of 
the pollen is brushed off the anthers and scattered on the 
bee. The pollen sticks to the bee’s body and some of it is 
certain to be carried to the stigma of the next flower the 
bee visits. The shape of the corolla is in this case specially 
adapted to cross-pollination by insects—for the nectar 
or honey gland is so placed that in order to reach it 
the insect must liberate and carry off some of the pollen. 
Quite a number of other flowers have special contrivances for 
securing cross-pollination by insects—such flowers in nearly 
all cases are bright-coloured 
or scented, possess nectaries 
for the sake of whose 
sweet juice the insects 
visit them, and their stig- 
xy) mas are usually small. 
IR (R J) ‘ 7 5 : 
| AQ) ie ZE- ; Cross-pollination may also 
G4 "a be brought about by the 
a anthers contain an im- 
mense number of pollen 
grains, and these, on being 
liberated, are scattered by 
Fig. 50.—Wheat Flower. the wind in all directions 
ee and often carried to con- 
siderable distances before finding a resting place on the 
stigmas of suitable flowers, The grasses, for instance, are 
pollinated in this way. If an ear of Wheat be examined 
when green, it will be found to consist of several rows 
of small flowers arranged upon a central stalk. A 
number of little yellow bodies will be seen hanging out 
of each ear—these are the stamens. The. anthers are 
attached to long filaments and hang freely out of the 
flowers, so that the pollen on being liberated may be 
—. 
“yy fp . 
\ 4} LEE agency of wind... The 
aay A 
