L02 



THE AMERICAN NATURALIST [Vol.XLVI 



spike of. Amarantus. At one time there were five bees 

 on the golden glow and only two on the spike of 

 Amarantus. 



At 2 :45 p.m., I repeated the preceding experiment, but 

 I placed the flower of the golden glow and the spike of 

 Amarantus on the south side of the feeder three feet 

 from its base, but only three, inches apart. Honey was 

 put on both at the beginning of the experiment. In ten 

 minutes there were 18 visits to the golden glow and 5 to 

 the green spike of Amarantus. At one time there were 

 four bees on the flower of golden glow, but only one on 

 the spike of Amarantus. It often happens when a bee 

 comes to a flower on which one or more bees are already 

 at work that they will all fly up in the air and then all or 

 in part settle down again. Such flights were not counted. 

 Frequently a bee flew directly to the golden glow as 

 though it had been seen from a distance. 



It will be remembered that Plateau put honey on the 

 green inflorescence of several species of Chenopodium, 

 besides other anemophilous flowers, and when it was 

 found by insects reasserted his oft-repeated conclusion 

 that winged pollinators are guided to flowers almost ex- 

 clusively by odor and that color contrast is of little value. 

 Plateau employed no control experiments, but it appears 

 from the experiments just described that though the odor 

 of the honey drew insects to the green inflorescence, 

 nevertheless it was at a disadvantage because of the 

 absence of bright coloration. 



In several of the experiments of 1909 a blue slide was 

 used, prepared by placing the leaves of the perianth of 

 the bee larkspur {Delphinium elatum) between two glass 

 object slides tied firmly together with black silk. It 

 might perhaps be objected that the scent of these floral 

 leaves would escape through the narrow crack between 

 the two glass slides. While I think this improbable, and 

 that in any event it would be so slight as to bear no com- 

 parison with that of the honey placed upon the upper 

 glass slip and, therefore, would exert no influence on the 



