“See,” she said, “Here is one buttercup they forgot to paint.”
I took the flower from her hand. I could not tell her just how it happened that this one perianth was white, but I explained to her something of how the others came to be yellow
What we call a flower is not, usually, the flower at all, but merely its petals. The real flower is the cluster, in the center of the calyx, of pistils and their surrounding pollen-bearing stamens. Away back in the ages when man had not yet developed his æsthetic sense, perhaps even before he had learned to make fire, the primitive flower bore only these pistils and stamens, with a little outer protective whorl of green petals. It was fertilized by the pollen falling upon the pistils.
But this was not good for the plant. Those flowers that in some way became fertilized by pollen from other plants of the same variety, by cross-fertilization, in fact, were healthier and stronger than those fertilized by their own pollen. In such plants as wind-blown pollen reached this cross-fertilization was an easy matter, but the buttercup is not one of these. It is forced to rely upon insects for fertilization. So the plant began to secrete a sweet drop at the base of each green petal. Such insects as discovered this nectar and stopped to sip were dusted with the pollen of the plant and carried it to other flowers, where it fertilized the pistils, the insect gathering from every blossom a fresh burden of pollen to be carried along on his nectar-seeking round. This was very good, so far as it went, but the flowers were pale and inconspicuous, and many of them, overlooked by the insects, were never visited. Certain ones, however, owing to accidents or conditions of soil and moisture, had the calyx a little larger, or brighter colored than their fellows, and these the insects found. It happened, therefore, if anything ever does merely happen, that the flowers with bright petals were fertilized, and their descendants were even brighter colored. Thus, in time, the buttercup, by the process which, for lack of a better name, we call natural selection, came to have bright yellow petals, because these attract the insect best adapted to fertilize it
If man’s æsthetic sense is gratified by the flower’s beauty, why man is by so much the better off, but that man is pleased by the bright color is not half so important to the buttercup as is the pleasure of a certain little winged beetle which sees the shining golden cup and knows that it means honey
