This

now abounding in the seas and oceans. period seems as full of immense numbers of fishes as the previous period was remarkable for the fragments of corals, shells, and the creatures of inferior organizations.

Fifth Period.

The next period was abundant in vegetable life of many varieties, which grew and flourished; many of them small, and many large and lofty.

The wreck of animals, fishes, and limeformed, broken, and disintegrated rocks, sand, and mud, becoming swampy, and in a degree dry sand, gave a base for plants and trees; and if we may judge from the immense fields of coal in Europe and America, these forests in places must have been very large, and in process of time, by floods or immense convulsions of nature, were cast into seas, lakes, and hollows; and there, firmly imbedded and acted on by heat, became coal of the various kinds, according to the trees of which it was formed.

Those trees do not appear as trees now do, to corrupt and decay, return to the air and

soil by which they had been nourished; but were laid up in immense store-houses, to become the real sources of heat in our dwellings, furnaces, and work-shops; of light in our great cities by gas, and of riches by its almost boundless use in the arts.

In some parts of Europe the remains of forests have been found converted into pitcoal, in which the trunks, branches, bark, and wood of trees are discernible.

In most of the varieties of coal, the impressions of vegetable matter, and particularly ferns, are easily discovered, and impressions of palms or vegetables, resembling those of the identical kinds of the living species.

In the United States there is probably not less than 163,000 square miles of this precious mineral, so unimportant to mere animals, but so exceedingly important to man.

This fact would seem to prove clearly that the great work going on had a direct reference to the future creation of man, and his benefit, welfare, and happiness; yet this mineral, so exceedingly valuable, was not used in Europe until a late period. Even in England wood was supposed to be necessary to burn coal; and when Marco Polo returned from China and re

ported the use of coal, it was regarded as a fiction.

In 1803 Mr. Fox, a tragedian in New York, who had recently returned from England, gave notice in the play-bills that he would exhibit a lamp burning without oil, spirits, lard, or tallow. On the appointed evening, he appeared on the stage as an astrologer, and placed a chafing dish on a stand, from the centre of which arose a tube six or eight inches high. To this tube he applied a taper, and it burnt with a clear, brilliant flame. He extinguished and relit it several times; when suddenly amid groaning, hissing, and rattling, the curtain fell. Yet the very article he employed was coal to produce a gas, which now so beautifully lights the cities of Europe and America.

This treasure, prepared and reserved for man, he received with suspicion, ridicule, and contempt, so slow has man been to see the very rich provision God has made for him millions of years before he was brought on the stage of action.

Here was a new creating act, a new work, making a great advance in preparing the earth for the abode of more perfectly organized animals, of various sizes and different habits. At

the same time the earth was becoming more adapted to all their wants.

It would be impossible in a treatise like this to follow out the subject of the coal formation, but we state the fact as evidence of vegetation at the time, in concurrence with the fossil remains of plants, as of ferns, palms, and other plants.

About this period we find also rich beds of argillaceous iron ore, often in the neighborhood of those great coal mines; a kindly provision to facilitate the reduction of the ore to a metallic state, while limestone, so useful as a flux to separate the metal from the ore, is always in immediate proximity.

There do not at this time appear any remains of quadrupeds or birds, although there were insects, and several kinds of shell animals.

The inhabitants of the seas were abundant, and they were sufficiently distinct to enable us to determine the various changes which had taken place. At this time also appeared the two large families of the Sauroid, or lizard-like race, the Megalichthys, or big fish race, an animal of peculiar shaped jaw, and armed with large, strong teeth.

These, however, were not the only inhabitants of the waters. Not less than sixty species are indicated by the fossil remains of their teeth, in various localities of limestone, sandstone, and shale of coal.

Sharks, the wolves of the ocean, abounded at the time, of various sizes and forms, rapid and powerful swimmers, very ferocious and carnivorous, judging from its teeth. This fish seems to have abounded in some of its forms in the various periods of geological history. The existence of more than one hundred and fifty species of fossil fish related to this ferocious family are known. They were associated with large fish, resembling reptiles of the present day, and fearfully powerful and voracious, feeding on their fellow inhabitants of the deep, as the monsters of the ocean do at this day.

At this period there was evidently a great advance in point of organization; yet that advance was not of such a nature as that an animal of lower organization can be supposed to pass into a higher and more perfect state, but clearly indicating a new creation of animals fitted to the state of the earth. They all doubtless had their enjoyments; and when they