WISCONSIN FLOWERS AND THEIR POLLINATION. 



By S. Graenicher. 



COMPOSITiE. 



PART i. 



Within the last 10 or 12 years a rather spirited ex- 

 change of views has taken place concerning the influence 

 of the color of flowers on the visits of insects. From 

 the time of Sprengel 1 on there has been a tendency to 

 consider color the principal means by which the flowers are 

 enabled to attract insect visitors. Hermann Mueller 2 in discussing 

 the effect of conspicuousness and odor in flowers states that "un- 

 der otherwise equal conditions a species of flower is the more 

 visited by insects the more conspicuous it is." Mueller came to 

 the conclusion that insects with a high degree of adaptation to 

 flowers, such as bees, butterflies and some specialized flies show 

 a preference for red, purple, and blue, while those poorly adapted 

 favor yellow and white. In Knuth's Handbook of flower pollina- 

 tion 3 we find the following passus : "It is the petals or perianth 

 leaves which, owing to their bright color, play the leading part in 

 bringing about conspicuousness in flowers, and in enticing cross- 

 pollinating insects to visit them." In several papers, the first of 

 which appeared in 1895 Plateau 4 published the details of his ob- 

 servations, and very carefully conducted experiments with differ- 

 ently colored flowers of his garden, as also with artificial flowers. 

 Summing up the results of his investigations Plateau 5 arrives at 

 the conclusion that insects are directed to the flowers mainly 

 through their sense of smell, and that the more or less vivid color- 



1) Christian Konrad Sprengel. Das entdeckte Geheimniss der Natur, 

 etc. 1793. 



*2) Hermann Mueller. Die Befruehtung der Blumen durch Insekten, 

 1873, p. 426. ._ ™. „ T 



English translation "The fertilization of flowers, by D Arcy w. 

 Thompson, p. 570. 



3) Paul Knuth. Handbueh der Bluetenbiologie, Vol. I., p. 100 



English translation by J. R. Ainsworth Davis "Handbook of flower 

 pollination," Vol. I., p. 83. , , 



4) Felix Plateau. Comment les fleurs attirent les insectes. 1st part. 

 (Bull. Acad, royale de Belgique, 3me serie, tome XXX., No. 11, Novem- 

 bre 1895 ) 



5) Felix Plateau. Les insectes et la couleur des fleurs. L'Annee psychol- 

 og-ique, tome XIII., pp. 67-79, (1907). In this paper reference is made to 

 Plateau's previous publications on this subject. 



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