The dissimilarity which obtains between the fossils of the contemporary formations of this system in England and Scotland, is instructive. The group in the one consists mainly of molluscous animals; in the other, almost entirely of ichthyolites, and what seems to have been algæ. Other localities may present us with yet different groups of the same period--with the productions of its coasts, its lakes, and its rivers. At present, we are but beginning to know just a little of its littoral shells, and of the fish of its profounder depths. These last are surely curious subjects of inquiry. We cannot catechise our stony ichthyolites, as the necromantic lady of the _Arabian Nights_ did the colored fish of the lake, which had once been a city, when she touched their dead bodies with her wand, and they straightway raised their heads and replied to her queries. We would have many a question to ask them if we could--questions never to be solved. But even the contemplation of their remains is a powerful stimulant to thought. The wonders of Geology exercise every faculty of the mind--reason; memory, imagination; and though we cannot put our fossils to the question, it is something to be so aroused as to be made to put questions to one's self. I have referred to the consistency of style which obtained among these ancient fishes--the unity of character which marked every scale, plate, and fin of every various family, and which distinguished it from the rest; and who can doubt that the same shades of variety existed in their habits and their instincts? We speak of the infinity of Deity--of his inexhaustible variety of mind; but we speak of it until the idea becomes a piece of mere common-place in our mouths. It is well to be brought to feel, if not to conceive of it--to be made to know that we ourselves are barren-minded, and that in Him "all fulness dwelleth." Succeeding creations, each with its myriads of existences, do not exhaust Him. He never repeats Himself. The curtain drops, at his command, over one scene of existence full of wisdom and beauty; it rises again, and all is glorious, wise, and beautiful as before, and all is new, Who can sum up the amount of wisdom whose record He has written in the rocks--wisdom exhibited in the succeeding creations of earth, ere man was, but which was exhibited surely not in vain? May we not say with Milton,-- Think not, though men were none, That heaven could want spectators, God want praise; Millions of spiritual creatures walked the earth, And these with ceaseless praise his works beheld?