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THE AMERICAN NATURALIST [Vol.XLVI 



two feet. There was a small quantity of honey on both. 

 One of these blossoms I screened with dandelion leaves 

 on the side toward the feeder, but it was visible in every 

 other direction. Some time after the honey was all con- 

 sumed on the feeder two bees flew over the unconcealed 

 flower but did not alight. A wasp (Vespula vidua 

 Sauss.) 24 found it and at the end of half an hour it was 

 visited by a bee. The partially concealed flower received 

 no attention. During this experiment the bees seldom in- 

 spected objects on the lawn though they frequently flew 

 to where I was sitting, ten feet away. 



The conclusion derived from a study of the phylogeny, 

 ecology, distribution and fertilization of green flowers 

 that they are at a disadvantage in attracting insects be 

 cause of their color was fully sustained by a long series 

 of experiments, in which honey-bees were given the choice 

 between a green and a bright colored object placed on a 

 green background, or between a conspicuous and an in- 

 conspicuous object. In the experiments described both 

 black and Italian bees were employed, the number of 

 which varied from one to fifty. The observations ex- 

 tended over portions of three seasons. Conspicuous and 

 inconspicuous objects were in some instances placed dia- 

 metrically opposite to each other at varying distances, 

 in other cases side by side or a few feet apart. In six 

 experiments there were no visits to the inconspicuous 

 object; while in the other experiments the number of 

 visits to the conspicuous object was much larger than to 

 the inconspicuous object, usually twice or three times as 

 large. The theory that bees in gathering nectar are in- 

 fluenced only by the olfactory sense and not by color or 

 form does not afford a satisfactory explanation of the 

 facts presented. If, however, bees are guided by the 

 sense of vision as well as by that of smell, then their rela- 

 tions both past and present to green flowers are not 

 difficult to understand. To reject a natural and wholly 



