682 THE AMERICAN NATURALIST 1 [Vol. XLIV 



slides for the fifth time. Two bees returned, one of which 

 alighted on the yellow, the other on the bine. There conld 

 be little doubt that the bee which alighted on the yellow 

 was the one which was under observation. This decision 

 was based partly on its appearance (young bees can easily 

 be distinguished from old ones), and partly because it 

 was probable that it would return to the yellow. Its sub- 

 sequent behavior satisfied me that this conclusion was 

 correct. The bee on the blue was removed. 



The bee on the yellow left for the hive and I transposed 

 the slides. It returned to the yellow. 



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

 The bee returned to the yellow, but presently left it, de- 

 scribed a few circles in the air, and then again settled on 

 the yellow. 



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

 for the eighth time. The bee returned to the blue, but 

 soon left it, and after circling around in the air alighted 

 on the yellow, where it remained. 



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

 It returned to the yellow. 



During ten visits in only one instance did it take up its 

 load on the blue. The dominant power of the yellow 

 color is well shown in the case where the bee alighted on 

 the blue, on which there was an abundance of honey, but 

 soon left it for the yellow. In many other experiments, 

 in which the red slide was used as well as the yellow and 

 blue, the bees as easily discriminated between natural 

 colors as between those which were artificial. 



On October 6 I performed the following experiment for 

 the purpose of determining whether bees were more 

 strongly influenced by a colored slide than by one without 

 color. A red slide, prepared from the bright red flowers 

 of Impatiens sultani, an exotic from Zanzibar, was placed 

 on a white box in the sun and about a dozen bees were 

 permitted to visit it for some time. Each of the blossoms 

 was an inch in diameter. At 10 o'clock in the morning a 

 plain glass slide was substituted for the red one, which 



