KINDS OF POLLINATION 47 



depend upon the wind for pollination. The wind is also an 

 important agent in the pollination of Corn and aids some in 

 orchard pollination. Plants having showy flowers depend upon 

 insects for pollination and it is among these plants that attractive 

 colors, secretions of nectar, and various structural arrangements, 

 which are interpreted as adaptations to secure pollination, occur. 

 The pollination of Fruit trees, Clovers, and Alfalfa is done chiefly 

 by insects. (Fig. 56.) In experimental work, such as crossing 



FIG. 56. Bumble bee pollinating Red Clover. 



Tomatoes, Corn, and Fruit trees, man himself often does the 

 pollinating so as to have it under control. 



Kinds of Pollination. On the basis of the relation of the 

 stamen furnishing the pollen to the pistil pollinated, there can 

 be different kinds of pollination. The transfer of pollen from 

 the stamen to the pistil of the same flower is self-pollination, 

 while the transfer to the pistil of another flower is cross-pollina- 

 tion. Various relationships may occur in pollination. Thus the 



