ECOLOGY OF FLOWERS; POLLINATION 169 
wind. Any one who has been much in cornfields after 
the corn has “ tasseled”’ has noticed the pale yellow dusty 
pollen which flies about when a cornstalk is jostled, and 
which collects in considerable quantities on the blades of 
the leaves. Corn is monecious, but fertilization is best 
accomplished by pollen blown from the ‘tassel’ (stamens) 
of one plant to the “silk” (pistils) of another plant. The 
pistil of wind-pollinated flowers is often feathery and thus 
adapted to catch flying pollen- 
grains (Fig. 125). Other charac- 
teristics of such flowers are the 
inconspicuous character of their 
perianth, which is usually green Fyg, 125, Pistil of a Grass, 
or greenish, the absence of odor provided with a Feathery 
and of nectar, the regularity of eae) ae Hoe Wines 
the corolla, and the appearance 
of the flowers before the leaves or their occurrence on 
stalks raised above the leaves. 
Pollen is, in the case of a few aquatic plants, carried 
from flower to flower by the water on which it floats. 
199. Insect-Pollinated Flowers. — Most plants which 
require cross-pollination depend upon insects as pollen- 
carriers,! and it may be stated as a general fact that the 
showy colors and markings of flowers and their odors all 
serve as so many advertisements of the nectar (commonly 
but wrongly called honey) or of the nourishing pollen 
which the flower has to offer to insect visitors. 
200. Pollen-Carrying Apparatus of Insects.? Ants and 
some beetles which visit flowers have smooth bodies to 
which little pollen adheres, so that their visits are often of 
1 A few are pollinated by snails; many more by humming-birds and other 
birds. 2 See P. Knuth, Handbuch der Bliithenbiologie. 
