69i ) 



THE AMERICAN NATURALIST [Vol. XLIV 



of our Composite the proportion of short-tongued to long-tongued 

 visitors in these flowers is determined by tube length more than by any 

 other character of the flower. 22 



In the flowers under consideration the important bar- 

 rier of difference in form is absent. 



In the following experiment it is shown how a bee soon 

 learns to visit colors indiscriminately. On September 22 

 after a black bee had been accustomed to visit a slip of 

 blue paper, a series of seven differently colored slides 

 were arranged in the following order : black, green, blue, 

 purple, red, white, yellow, orange. The slides were three 

 inches apart, or twenty-two inches from end to end; and 

 there was a small quantity of honey on the center of each. 

 The bee returned the first time to the blue, the second 

 time to the purple, the third time to the purple, the fourth 

 time to the blue, the fifth time to the purple. It will be 

 observed that the bee ceased at once to discriminate be- 

 tween the blue and the purple — the two slides being ad- 

 jacent and allied in color. On its fifth visit before alight- 

 ing the bee hovered over the different colors for many 

 seconds, and later left the purple for the red, whence 

 after a brief stop it flew away to the hive. 



During the next three visits the bee devoted much time 

 to the examination of the slides, but subsequently it paid 

 little attention to the colors. When the bee returned 

 from the hive, it flew about for a long time, touched on the 

 orange, but immediately left it and went to the blue. On 

 its seventh visit the bee after describing a few circles in 

 the air, touched on the red, then on the blue, went back to 

 the red, and finally stopped on the blue. The colors were 

 arranged in the following order : black, red, blue, white, 

 green, orange, purple, yellow. On its eighth journey be- 

 fore alighting the bee flew from the vicinity of the blue 

 over to the yellow and back to the blue where it remained. 

 There could be no doubt that it was examining the slides, 

 as it flew close to them touching them at times. 



I transposed the blue and green slides so that the order 



*Graenicher, S., "Wisconsin Flowers and their Pollination— Compos- 

 itaV' Bull, Wis. Nat. Hist. Soc, 7, 42, April, 1909. 



