THE FLOWER AND THE BEE 



manifestly for the advantage of both insects and flowers. In 

 the case of a number of bees flying for only a small part of the 

 season this habit has become so specialized that they visit 

 only one or a few allied species of flowers, which offer an abun- 

 dance of pollen and nectar. As the honey-bee for a time re- 

 stricts its visits to the white clover, so in like manner a mono- 

 tropic bee visits but a single kind of flower. But in the former 

 case the bee flies throughout the whole season; but in the latter, 

 when the flower fades, the bee's period of flight is over. 



The idiosyncrasies of bees in visiting flowers present many 

 remarkable peculiarities, and undoubtedly offer an attractive 

 field for observation. There are certain bees which, though 

 they are not oligotropic, obtain the larger part of their supplies 

 from comparatively few flowers, as the plums, thorn-bushes, 

 cornels, and viburnums. In this locality one of the leaf -cutting 

 bees {Megachile melanophcsa) shows a decided preference for 

 the purple vetch (Vicia Cracca), and if I desired a specimen I 

 should look for it on the blossoms of this plant. Since the 

 male bees do not gather pollen they may not visit the same 

 flowers as the females, though the attraction of the female may 

 largely influence their course, in which respect they exhibit 

 quite human sentiments. It would, of course, be in vain to 

 look for the males of Bomhus and Halictus on the flowers of 

 spring, since they do not appear until midsummer. In the 

 case of dioecious plants, or plants in which the sexes are on dif- 

 ferent individuals, the bees visiting the staminate flow^ers are 

 more numerous and are sometimes widely different from those 

 visiting the pistillate. The common sumac is a good example. 

 Indeed, the bees visiting a flower in its early stages may differ 

 from those visiting it in its later stages. Again the visitors to 

 a flower may differ, both in number and kind, in different sea- 

 sons. 



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