186 PRINCIPLES AND CONCLUSIONS. 



artificial flowers used by Miss Wery were regarded as imitations of very 

 mediocre value. 



In the experiments where Dahlia was used, Plateau stated that the 

 figures probably did not really indicate that the artificial flowers were 

 practically as attractive as the natural ones, for three reasons. The first 

 was the error committed in carrying out these tests where a series of 8 

 experiments with bouquets had been made during the preceding two weeks, 

 giving an opportunity for the exercise of place-memory by the bees. The 

 second was the fact that the majority of the insects barely landed on the 

 artificial flowers, these visits to be interpreted rather as hesitations, curves, 

 or crochets made in flight, and the third dealt with the materials used in 

 the artificial flowers. 



Experiments of Weismann and Errera. — Weismann (1902:219) 

 placed an artificial Chrysanthemum in the midst of normal flowers actively 

 visited by butterflies. He found that most of the latter passed near the 

 imitation without stopping, but he saw two alight on it and probe actively 

 with the ligule before flying away. It seemed evident that they sought the 

 nectar which they had found in the normal flowers and that they flew off 

 only after having determined its absence. Errera (Wery, 1904:1224) 

 placed two bouquets made up of the same number of flowers of the same 

 species in similar vases at a considerable distance from each other in the 

 midst of an extensive greensward at Brussels. In one the flowers were 

 normal, in the other they were deprived of their corollas in such a way as 

 not to injure the nectaries. The decorollate bouquet was still rather con- 

 spicuous, owing to the colored stamens of Rhododendron, the white calyx 

 of Hesperis, and the yellow disks of Chrysanthemum. The two bouquets 

 were visited at the rate of 46 per hour for the normal and 24 for the de- 

 corollate, the majority of the visitors being flies. 



Orientation of the honey-bee at flowers of the same species. — 



Detto (1905:424) carried out a number of experiments to determine the 

 relative importance of color and odor in the attraction of the honey-bee, 

 as well as to throw light upon the rapidity with which it learned. The 

 first series dealt with the manner in which the bee is led from one flower to 

 another of the same plant or different plants of the same species. When 

 flowers were mutilated by removing the anther mass or half the corolla, they 

 were visited like the normal ones, but when the corolla was completely sup- 

 pressed, visits ceased immediately, to begin again as soon as it was replaced. 

 Visits also stopped at once as soon as the corolla was replaced by one of 

 yellow tissue-paper, but were resumed when the normal corolla was put in 

 position again. Shortening the corolla to a third did not affect its attraction, 

 and finally, after a few hours the decorollate flowers began to receive visitors, 

 but in a smaller degree than the normal ones. These tests show how im- 

 portant a guide the colored corolla is in the near-flight of habituated honey- 

 bees, and the visits to decorollate flowers merely prove that they are able 

 to form new associations in consequence of the stimulus afforded by the 

 abundant nectar. If flowers with excised anther column were provided 

 with a colored paper disk with a hole in the center, thus cutting off the 

 lower third of the flower, part of the bees avoided such flowers and others 



