Page:Popular Science Monthly Volume 25.djvu/354

342 piece of decaying meat. Moreover, certain insects show a preference for certain special flowers over others. One may watch for hours the visits paid by a bee or a butterfly to several dozens of one flower, say a purple lamium, in succession, passing by unnoticed the white or yellow blossoms which intervene between them. Fritz Müller mentions an interesting case of a lantana, which is yellow on the first day, orange on the second, and purple on the third. "This plant," he says, "is visited by various butterflies. As far as I have seen, the purple blossoms are never touched. Some species inserted their probosces both into yellow and into orange flowers; others, as far as I have observed, exclusively into the yellow flowers of the first day." Mr. T. D. Lilly, an American naturalist, observed that the colored petunias and morning-glories in his garden were torn to pieces by bees and butterflies in getting at the honey, while the white or pale ones were never visited. These are only a few sample cases out of hundreds, in which various observers have noted the preference shown by insects for blossoms of a special color.

Again, we may ask. Do different species of insects show different degrees of æsthetic taste? The late Dr. Hermann Müller, who specially devoted himself to the relations between insects and flowers, showed most conclusively that they do. The butterflies, which are at once the most locomotive and most beautiful of their class, appear to require larger masses of color for their attraction than any other group; and the flowers which depend upon them for fertilization are, in consequence, exceptionally large and brilliant. Müller attributes to this cause the well-known beauty of Alpine flowers, because bees and flies are comparatively rare among the higher Alps, while butterflies, which rise to greater elevations in the air, are comparatively common; and he has shown that, in many cases, where a lowland flower is adapted for fertilization by bees, and has a small or inconspicuous blossom, its Alpine congener has been modified so as to be suited for fertilization by butterflies, and has, therefore, brilliant bunches of crimson or purple blossoms. In his last work, he shows that, while bees form as many as seventy-five per cent of the insects visiting the beautiful and attractive composites, they form only fourteen per cent of those which visit the plain green and white umbellates, like the wild-carrot and fool's-parsley. Butterflies frequently visit the composites, but almost never the umbellates, which last depend mainly upon the smaller flies and other like insects. Of two small hedge-flowers (Galium mollugo and G. verum), Müller notes that they agree closely in other points, but the first is white, while the second is yellow, which, he says, renders it more attractive to small beetles. Of certain other flowers, which lay themselves out to attract wasps, Müller quaintly observes that they are obviously adapted "to a less æsthetically cultivated circle of acquaintances." So that the close studies of this accurate and painstaking naturalist led him to the conclusion that