Page:The evolution of worlds - Lowell.djvu/227

Rh bold adventurers, their skies were only clearing, as the pitting of the sandstone eloquently states.

It was not till the chalk cliffs of Dover were being laid down that we have evidence that seasons had fully developed, in the shape of the first deciduous trees. Cryptogams, cycads, and, finally, conifers had in turn represented the highest attainments of vegetation, and the last of these had already recognized the seasons by a sort of half-hearted hibernation or annual moulting; deeming it wise not to be off with the old leaves before they were on with the new. But finally the most advanced among them decided unreservedly to accept the winter and go to sleep till spring. The larches and ginkgo trees are descendants of the leaders of this coniferous progressive party.

At the same time color came in. We are not accustomed to realize that nature drew the Earth in grays and greens, and touched it up with color afterward. Only the tempered tints of the rocks and the leaden blue of the sea, subdued by the disheartening welkin overhead to a dull drab, enlivened their abode for the oldest inhabitants. But with Tertiary times entered the brilliantly petalled flowers. Beginning with yellow, these rose through a chromatic scale of beauty from white through red to blue. They decked themselves