ing hills of our familiar Europe, we should probably see the interior country composed only of low ridges, unlifted as yet by the slow upheaval of ages into the Alps or Pyrenees of the modern continent. But the most striking peculiarity of the scene would doubtless be the wearisome uniformity of its prevailing colors. Earth beneath and primitive trees overhead would all alike present a single field of unbroken and unvarying green. No scarlet flower, golden fruit, or gay butterfly would give a gleam of brighter and warmer coloring to the continuous verdure of that more than tropical forest. Green, and green, and green, again; wherever the eye fell it would rest alike upon one monotonous and unrelieved mass of harsh and angular verdure.
On the other hand, if we turn to a modern English meadow, we find it bright with yellow buttercups and purple clover, pink-tipped daisies and pale-faced primroses. We see the hedges white with may or glowing with dog-roses. "We find the trees overhead covered with apple-blossom or scented with horse-chestnut. While in and out among the beautiful flowers flit equally beautiful butterflies—emperors, admirals, peacocks, orange-tips, and painted ladies. The green of the grassy meadow and the blue of the open sky serve only as backgrounds to show off the brighter hues of the beautiful blossoms and the insects that pay court to them incessantly.
To what is this great change in the general aspect of nature due? Almost entirely, we may now confidently conclude, to the color-sense in the insects themselves. The lovely tints of the summer flowers and the exquisite patterns on the butterfly's wings have alike been developed through the taste and the selective action of these humble little creatures. To trace up the gradual evolution of the insect color-sense and its subsequent reactions upon the outer world, we must go back to a time when neither flower nor butterfly yet existed.
In the carboniferous earth we have reason to believe that almost all the vegetation belonged to the flowerless type—the type now represented among us by ferns and horse-tails. These plants, as everybody knows, have no flowers, but only spores or naked frondlets. There were a few flowering plants it is true, in the carboniferous world, but they belonged entirely to the group of conifers, trees like the pines and cycads, which bear their seeds in cones, and whose flowers would only be recognized as such by a technical botanist. Even if some stray archaic members of the true flowering groups already existed, it is, at any rate, almost certain that they must have been devoid of those gay petals which distinguish the beautiful modern blossoms in our fields and gardens.
A flower, of course, consists essentially of a pistil or seed-producing organ, and a certain number of stamens or fertilizers. No seed can come to maturity unless fertilized by pollen from a stamen. But experience, and more especially the experiments of Mr. Darwin, have
