EXPERIMENTS WITH COLORED PAPERS. 195 



returned to the old spot, and was just going to alight, 

 when she observed the change of color, pulled herself 

 up, and without a moment's hesitation darted off to the 

 blue. No one who saw her at that moment could have 

 the slightest doubt about her perceiving the difference 

 between the two colors. 



I also made a number of similar observations with 

 red, yellow, green, and white. But I was anxious to 

 carry the matter further, and ascertain, if possible 

 whether they have any preference for one color over 

 another, which had been denied by M. Bonnier. To 

 test this I took slips of glass of the size used for slides 

 for the microscope, viz. three inches by one, and pasted 

 on them slips of paper of the same size, coloured re- 

 spectively blue, green, orange, red, white, and yellow. I 

 then put them on a lawn, in a row, about a foot apart, 

 and on each put a second slip of glass with a drop of 

 honey. I also put with them a slip of plain glass with a 

 similar drop of honey. I had previously trained 

 a marked bee to come to the place for honey. My 

 plan then was, when the bee returned and had sipped 

 for about a quarter of a minute, to remove the honey, 

 when she flew to another slip. This I then took away, 

 when she went to a third, and so on. In this way, as 

 bees generally suck for three or four minutes, I induced 

 her to visit all the drops successively before returning 

 to the nest. When she had gone to the nest, I trans-- 

 posed all the upper glasses with the honey, and also 

 moved the colored glasses. Thus, as the drop of honey 

 was changed each time, and also the position of the 

 colored glasses, neither of these could influence the 

 selection by the bee. 



In recording the results, I marked down successively 



