THE WORK OF WINDS AND INSECTS 149 



known with certainty. All we can be sure of is that, 

 for some reason, she does not usually tackle flowers of 

 those tints, but seems to keep away from them. 



Somebody has suggested, as a possible explanation, 

 that bees may suffer from " colour-blindness." Men 

 are often more or less " colour-blind," and cannot 

 distinguish certain hues, such as red from green. Possi- 

 bly bees may have some such defect of vision, so that 

 they cannot see red or orange-red blossoms ; in which 

 case, naturally, they would not go to them. 



In a general way gay flowers do undoubtedly draw 

 many insects. It is interesting to notice that those 

 trees which depend chiefly on winds to carry about their 

 dusty pollen, and which therefore do not need the help 

 of insects, have usually small and dull flowers, easily 

 overlooked. While plants which depend mainly on 

 insect- visitors, have generally larger and brighter blooms. 



Bees seem long ago to have discovered that what 

 they want is more often to be found in the gayer flowers. 

 How far this really has been due to " finding out for 

 themselves," and how far to simple " instinct," it is 

 impossible to say. 



With most insects a large amount of instinct is found. 

 By this we mean a kind of knowledge which is born 

 with them, inherited by them, and not knowledge which 

 is gained later through experience. But with such 

 possession is also found a certain amount of power to 

 learn from observation and practice. To decide in any 

 particular instance exactly how far action has arisen 

 from blind instinct, and how far from " finding out," is 

 very difficult. 



