80 



SOURCES OF NECTAR 



Among the important pollen plants may be mentioned several 

 of the forest trees, including the willows, elms and maples already 

 mentioned. In addition the box elder, walnut, hickory, ash, 

 beech, birch, chestnut and aspens may be mentioned. 



Fia. 45. — Where sufficiently abundant, the wild cucumber is valuable. 



Corn is one of the most abundant pollen plants of its season, 

 and the bees sometimes work on the tassels so freely as to give 

 rise to the impression that it is a honey producer. Plant lice are 



