CHAP. XXII WIND- AND INSECT-POLLINATION 95 



CHAPTER XXII 



WIND- AND INSECT-POLLINATION 



FEW flowers can be said to be pollinated exclusively either 

 by the wind or by insects, but their special structure adapts 

 them to be pollinated generally by either one or the other. 



I. Wind-Pollinated Flowers. These are usually not 

 showy, that is, neither large nor of conspicuous colors, nor 

 do they possess odors or nectar. The student should exam- 

 ine the flowers of the various Plantains, the Nettles, the 

 Alders (but not the Willows), the Walnuts, Hickory-nuts, 

 Butternuts, the Oaks, and the Birches for examples of the 

 wind-pollinated flowers. This should be done out of doors 

 and the results written in the note-books. The Grasses, 

 particularly Rye, Oats, Timothy, and above all Indian Corn, 

 should be examined. The method in which the anthers are 

 attached to the filaments and the protruding feathery stigmas 

 of the Grasses should be noted and sketched ; and the way 

 in which these assist in pollination described. 



II. Insect-Pollinated Flowers. Studies in the field 

 should be made upon this subject also, attention being 

 directed to the following points : 



i. Color. 



(a) What colors are more conspicuous by day? 

 What by night? 



