676 THE AMERICAN NATURALIST [Vol. XLIV 



blue slide, flew across to the red, but at once returned to 

 the blue. 



The bee left for the hive and I transposed the slides. 

 On its return it circled about as though in doubt and 

 presently disappeared from view ; but a little later it re- 

 turned and settled on the blue. While taking up its load 

 of honey it left the blue three times, but in each instance 

 returned. 



The bee left for the hive and I transposed the slides. 

 It returned to the blue. 



The bee left for the hive and I transposed the slides 

 for the eighth time. On returning the bee hovered close 

 to the red, and then went to the blue. 



As soon as the bee returned to the hive, I transposed 

 the slides for the ninth and last time. When the bee 

 came back, it alighted after a little hesitation on the blue. 

 It left once and flew across to the red, but soon returned 

 to the blue. Left a second time but soon returned. Then 

 it flew into the room, and on being released went back to 

 the hive. 



There can be no question that in this experiment the 

 honey-bee was able to distinguish the blue color from the 

 red. I repeated the experiment many times and varied 

 it in many different ways, but the bee always showed its 

 ability to distinguish between differently colored slips of 

 paper. Only one bee should be employed, for if there are 

 two or three they will conflict and to some extent produce 

 confusion. 



For the purpose of comparison the following experi- 

 ment, in which a larger number of colored slides was 

 employed, was performed on the morning of September 

 20, six days after the experiment just related. A black 

 or German bee, instead of an Italian bee as before, was 

 accustomed to visit a blue slide prepared as described 

 above. After a number of visits had been made, the blue 

 slide was moved to the right about seven inches, and a 

 red slide put in its place. The bee returned to the blue. 



As soon as the bee left for the hive, the slides were 



