RELATED STUDIES AND CRITIQUES. 185 



another containing mignonette, with marked perfume and dull color; the 

 former was visited by 35 bees, the latter by 6. When the bouquet of normal 

 blossoms was replaced by one of artificial flowers, equally brilliant, the figures 

 were 25 and 6. In the final installation, made first on a day with few bees 

 flying, 6 bees went to a dish of honey to which natural flowers were added, 

 4 to one with artificial flowers, and none to honey alone or with green leaves 

 merely. In the check, the dish with natural flowers gave 14 visitors, that 

 with artificial ones 15 visitors, and the honey with leaves or honey alone, 

 none. Finally, the author endeavored to give a numerical expression to 

 attraction by means of a table of her own results, as well as one for those 

 of Andreae and Giltay. The conclusions drawn were as follows : 



1. Flowers provided with brightly colored parts have a much greater attraction 



for the honey-bee than those of the same species when deprived of these parts. 



2. Honey attracts bees very little. 



3. Under the conditions given, artificial flowers attracted honey-bees readily, to the 



same degree as normal flowers placed in a globe. 



4. Perfume alone attracts bees but feebly, while bright color and form taken together, 



but detached from odor, exercise a very manifest attraction upon them. 



5. From the juxtaposition of the three principal factors, form, color, and odor, 



associated in the memory, results the most marked attraction. 



6. For the honey-bee the attraction exerted by the form and color of flowers is approxi- 



mately four times greater than that of their pollen, perfume, and nectar taken 

 together. Thus, if the total attraction exerted by the most attractive flowers 

 is taken as 100, that of form and color will be represented by about SO and 

 that of the other three factors by about 20. 



Plateau's criticisms of Wery's experiments. — In discussing the 

 discrepancy between his results and those of Wery and Andreae in particular, 

 Plateau (1906:11) thought it probable that this was due to certain dis- 

 turbing factors. In order to discover these, it appeared necessary to 

 secure conclusive evidence as to the nature of the materials employed by 

 his opponents, and to repeat their experiments and add new ones surrounded 

 by all possible precautions. A preliminary examination showed that certain 

 artificial flowers of commerce are only partly artificial; thus the yellow 

 disk of oxeye daisies consisted of the natural receptacle dried and dyed, 

 the involucre of the cornflower was simply the natural one dried, etc. 

 Moreover, the stiffness of the petals in artificial flowers for hats is secured 

 by means of a large amount of starch and the anthers are composed of balls 

 of paste, which are eaten by small Hymenoptera. He then obtained samples 

 of the flowers used by Wery and found his suspicions to be confirmed. In 

 all the flowers their rigidity was due to the presence of starch. The yellow 

 color of Helianthus and Eschscholtzia was derived from a saffron dye obtained 

 from the stigmas of Crocus sativus and containing a yellow glucoside ac- 

 companied by a volatile odor attractive at least to certain insects. The 

 disk flowers of Dahlia were made of yellow fibers, some of which were covered 

 with gum and rolled in flour. Balls of wheat flour colored yellow consti- 

 tuted the yellow center of Aster, and the anthers of Eschscholtzia were 

 made of similar starchy material colored blue by iodin. Although it was 

 not supposed that the presence of such substances explained all the dif- 

 ferences, it was thought to be responsible for them in part. Finally, the 



