Page:Popular Science Monthly Volume 25.djvu/355

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OUR DEBT TO INSECTS.
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insects differ greatly from one another in their taste for color. Probably we shall be right if we say that the most æsthetic among them all are the butterflies, and next the bees—these two classes having undergone the most profound modifications in adaptation to their flower-haunting life—and that the carrion-flies and wasps bring up the rear.

Is there any evidence, however, that insects ever notice color in anything else but flowers? Do they notice it in their own mates, and use it as a means of recognition? Apparently they do, for Mr. Doubleday informed Mr. Darwin that white butterflies often fly down to pieces of white paper on the ground, mistaking them doubtless for others of their species. So, too, Mr. Collingwood notes that a red butterfly, let us say, nailed to a twig, will attract other red butterflies of the same kind, or a yellow one its yellow congeners. When many butterflies of allied species inhabit the same district, it often happens that the various kinds undergo remarkable variation in their coloring so as to be readily recognizable by their own mates. Again, Mr. Patterson noticed that certain blue dragon-flies settled in numbers on the blue float of a fishing-line, while two other species were attracted by shining white colors. On the whole, it seems probable that all insects possessing the color-sense possess also a certain æsthetic taste for colors.

Indeed, it is difficult to see how it could be otherwise. Whenever an animal exercises a faculty much, the exercise comes to have pleasant feelings attached to it; and this is especially the case with all sense-organs. Creatures which live on honey love sweet things: carnivores delight in the taste of blood. Singing birds listen with interest to musical notes: and even insects will chirp in response to a chirp like their own. So, creatures which pass all their lives in the search for bright flowers must almost inevitably come to feel pleasure in the perception of brilliant colors. This is not, as so many people seem to think, a question of relative intellectual organization: it is a mere question of the presence or absence of certain sense-centers.

But it may finally be urged that, even though insects recognize and admire colors in the mass, they would not notice such minute and delicate patterns as those on their own wings. Let us see what evidence we can collect on this head. First of all, insects have not only produced the petals of flowers, but also the special markings on those petals. Now, these markings, as Sprengel pointed out a century since, bear a constant reference to the position of the honey, and are in fact regular honey-guides. If one examines any flower with such marks upon the petals, it will be found that they converge in the direction of the nectaries, and show the bee or butterfly whereabout he may look for his dinner. Accordingly, they must have been developed by the gradual action of insects in fertilizing most frequently those flowers which offered them the easiest indication of where to go for food. Unless insects noticed them, nay more, noticed them closely and accu-