FLOWERS AND INSECTS 445 



wasps are mimicked by beetles; certain conspicuously 

 marked beetles, such as the potato beetle, are mimicked 

 in turn by grasshoppers ; a well known leaf hopper insect 

 bears a striking resemblance to the powerful and aggres- 

 sive leaf-cutting ant; and there are many spiders which 

 significantly are very similar to the flies upon which they 

 feed. Among the butterflies there are also many species 

 which mimic distasteful ones, and a few which resemble 

 bees or wasps. 



Flowers and Insects. — Although plants in general 

 do not possess as definite, or at least as remarkable adapt- 

 ations as characterize animals, there are many species 

 which prove an exception to the rule. This is especially 

 the case with plants in relation to insects. As is well 

 known, the great majority of flowering plants produce 

 pollen and ovules whose union is necessary to produce 

 seeds. The sex-cells may be the product of the same 

 individual or more frequently of different plants. Fur- 

 thermore, the pollen may be carried by the wind, as in 

 the case of most forest trees and grasses, or it may be 

 transported by insects. The wind-pollinated flowers are 

 small, scentless, and inconspicuously colored. Those 

 pollinated by insects are larger, conspicuously colored, 

 and are frequently provided with nectar and distinc- 

 tive odors. The presumption is that the flowers of the 

 latter class are thus adapted to attract insects. This 

 has actually been proved to be the case with many 

 species. 



In the first place it can easily be seen that bees, flies, 

 butterflies, moths, and even humming birds, in their 

 search for nectar, become more or less coated with pollen 

 as they journey from flower to flower. It has been con- 

 clusively demonstrated that during these visits the pollen 

 of one flower is dislodged in another. Moreover, it has 

 been experimentally proved that the honey-bee is espe- 

 cially attracted by colors. Wasps have also been shown 

 to be attracted by color, and it is probable that many 



