THE FLOWER AND THE BEE 



and that, if it is non-existent, its absence registers a failure on 

 Nature's part to make the most of an opportunity. 



According to the teachings of Sprengel, Darwin, and Mueller, 



Fig. 101. Bean. Vida Faba 



Color contrast, a black spot on the wings of the papilionaceous 

 white corolla 



and most other flower-biologists, the bright hues of flowers 

 serve as signals, or flags, to attract the attention of insects 

 living on pollen and nectar. The more conspicuous a flower, 

 or flower-cluster, the better are its chances of pollination. 



210 



