170 WILD FLOWER PRESERVATION 



Cross-Fertilization. Many plants occasion- 

 ally or invariably require pollen from another 

 flower before they can produce good seed. (79) 



AGENTS IN CROSS-FERTILIZATION. 

 Pollen is carried from flower to flower (1) 

 by insects, (2) by the wind, (3) by water, and 

 (4) by birds. Of these the chief agents are 

 insects and the wind. 



DIFFERENCES BETWEEN INSECT-FERTILIZED 



(ENTOMOPHILOTJS) AND WIND-FERTILIZED 



(ANEMOPHILOUS) FLOWERS. 



As a rule there is a great difference between 

 insect- and wind-fertilized flowers, both in 

 structure and appearance. 



INSECT-FERTILIZED FLOWERS. 

 The. Corolla. This is usually either large, 

 curiously shaped, attractively colored, spotted, 

 streaked, or sweetly or disagreeably scented, 

 according to the taste of the insects required 

 to cross the flower. Some white and pale yel- 

 low flowers open only at night to attract night- 

 flying insects, and for the same reason some 

 flowers are more strongly scented then. 



