22 



INSECTS 



Plants which depend upon the wind for pollination 

 usually produce a light pollen in great quantity, so that 

 at times the air may be full of it. Plants which depend 

 upon insects for pollination may produce much or little ; 

 but it is usually somewhat sticky so as to adhere readily 

 to the body or vestiture of the visitor. And as insects are 

 not altruistic enough to call on the flowers merely to 

 benefit them, some sort of attraction must be offered 



FIG. 5. Section through a flower, illustrating the reproductive parts. 



to invite the visits. This attraction may be in the shape 

 of honey or nectar for those species who seek for them- 

 selves alone, or for their progeny; or in the shape of 

 pollen suitable for use as food directly or in preparing 

 food for the young of the visitor. 



Where nectar alone is relied upon to attract, it is 

 usually stored so as to compel the insects to come into 

 contact with the reproductive organs in their efforts to 

 reach it; and in such cases, not infrequently, the flowers 

 are modified to invite special kinds of insects only. 



