Page:Evolution of Life (Henry Cadwalader Chapman, 1873).djvu/159

117 harmony with what we know of the Carboniferous fossils. The gorgeous Ferns, in great variety, the Lycopod-like plants, having attained the full maturity of their luxuriant growth after this period, give way to the Cycadæ and Coniferæ. The Ganoid fishes die out, their posterity, the Batrachia, having appeared, soon to be replaced, however, by the Reptilia, while the Insects are still represented by the lowest orders just mentioned. Following the Carboniferous rocks of the West in this country, and closely resembling the Carboniferous period in its general features, we meet the Permian, called after the ancient kingdom of Permia in Russia. It is interesting to the Evolutionist as furnishing the remains of the simplest reptiles, the Proterosaurus having been found in the Permian rocks of Germany. By looking at the tree of the development of the Reptilia, it will be seen that the Proterosaurus is regarded as the common ancestor of that group. The Silurian, Devonian, Carboniferous, and Permian periods, taken together, constitute the Primary Age, or age of most ancient beings.

The Secondary, like the Primary Age, is subdivided into three periods, the Triassic, Jurassic, and Cretaceous. These three periods, while differing considerably in minor respects, agree essentially in their plants and animals, being principally represented by Cycadæ and Reptilia.

This period derives its name from the formation in Germany being composed of three kinds of rock; the name, however, is one of only local application; the period being often called in England and America the New Red Sandstone, as distinguished from the Old Red, or Devonian. The absence of Lepidodendrons and Sigillariæ in this period,