THE AMERICAN NATURALIST. [Vol. XXXVII. 



yellow is the color of honey and pollen the more acute insects 

 may from long experience, as in the case of yellow honey-guides, 

 associate this color with the presence of a supply of food. 

 Another group of flowers have nauseous or indoloid odors due 

 to the decomposition of some nitrogenous compound. They are 

 often flesh-colored, blood red, dull dark purple or red, and some- 

 times they are marked with livid stripes or spots. By some 

 authors they are regarded as resembling putrifying flesh or decay- 

 ing carcasses. In most instances the resemblance is not very 

 apparent. Malodorous flowers with other colors as yellowish 

 green or white also occur. These flowers are visited by carrion 

 and dung flies belonging to such genera as Musca, Lucilia, 

 Sarcophaga, and Scatophaga, which are believed to find the 

 supposed resemblance to putrid substances attractive. While 

 there is no improbability in this supposition, it is chiefly, if not 

 entirely, the nauseous odors which attract these insects. The 

 lurid coloring may often be explained by peculiarities of the 

 plants in the production of pigments, as in the Balanophoraceae, 

 where not only the inflorescence but the whole plant is vividly 

 colored. There are also a large number of flowers with strong 

 scented rather than repulsive odors, which are attractive to flies, 

 as Ancthum gmvcolcns and some Umbelliferas. 



Lepidoptera. Various birds and mammals, as is well known, 



become greatly excited when a red object is held before them. 

 Humming-birds and honey-suckers are attracted by fire-red and 

 scarlet colors. Kerner has pointed out that flowers of these 

 colors are more abundant in the Tropics and in South Africa, 

 where these birds are most numerous ; while they are rare in 

 Europe where there are no humming-birds. There would seem 

 to be no a priori reason why butterflies, as Muller believed, may 

 not be strongly influenced by red coloration. Of eight Alpine 

 butterfly flowers (Orchis globosa, Li Hum mariagon and L.bulbi- 

 fcntm, Gymnadcnia odoratissima, Dianthus supcrbus, IX silvcs- 

 tris, D. atroruber and Daphne striata), all were red colored. 

 Other red butterfly flowers are species of Silene, Lychnis and 



On the other hand three species of GlobuTaria with light blue 

 flowers are adapted to butterflies, "the only instance in the 



