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THE AMERICAN NATURALIST [Yol.XLVI 



38 greenish and 12 brownish or brown flowers, to the 

 larger part of which insect visits had been observed by 

 himself or other floroecologists. Of 72 of these forms he 

 examined the color himself and observed insect visits to 

 63 of them, or more than two thirds. Plateau believed 

 that the visits of insects to green flowers very strongly 

 supported his views, and in one of his last papers on the 

 pollination of Listera ovata, an orchid with green flowers,, 

 he again returns to this subject. In a letter to the writer 

 he states that he had made innumerable observations on 

 the pollination of green flowers, which had extended over 

 twelve years. His conclusion as finally expressed is as 

 follows : 



It is not the colors more or less bright of the corollas but other causes 

 which guide to flowers their winged pollinators. Green or greenish 

 flowers notwithstanding their hue similar to that of foliage are as 

 effectively fertilized by insects as white, blue, red, or yellow flowers, 

 consequently, all these floral colorations might disappear from nature- 

 without the pollination and reproduction of plants being diminished. 3 



It is desirable to examine briefly the pollination of 

 green flowers and to consider whether this conclusion is 

 sustained or not. 



A familiar example of a yellowish-green flower attract- 

 ive to insects is offered by the garden asparagus (As- 

 paragus officinalis). The flowers are mellifluous, pleas- 

 antly scented and frequented by honey-bees and less 

 often by smaller species of bees. Muller says that "in 

 spite of their inconspicuous color they are easily visible 

 at a distance"; but Plateau describes them as "peu 

 visible," an illustration perhaps that an observer is apt 

 to be influenced by his point of view as well as bv the 

 color of the flower. As the result of personal trial I find 

 that they can be distinctly seen at a distance of at least 

 fifty feet. Another yellowish-green flower is Tilia ulmi- 

 ' folia, or basswood, which, according to both Muller and 

 Plateau, is sought by honey-bees in immense numbers. 

 This is also true of the American basswood {Tilia ameri- 



3 Plateau, F., "La pollination d'une orchidee a fleura vertes 'Listera 



