Geology farther informs us, that, at different times, all the animated tribes which had peopled the earth's surface passed away, or became extinct, and were replaced by new species of different organization and characteristics; and probably at many other periods, as well as on occasions of some great catastrophe in the earth's crust, races wholly unlike any that had preceded them were introduced, from time to time, as new inhabitants of the globe. Here, then, was an absolute necessity for the continuous operation of an intelligent creative power, apart from the blind mechanical laws, which, at the utmost, could only allow each species, once introduced, to continue its kind. The marvellous adaptations of these new races to the altered conditions of the earth's surface when they appeared, then, become additional proofs of the wisdom and constant oversight of a designing Creator. They came not till all things were ready; they appeared when the extinction of former tribes had left a gap for them in the scale of being. The gradual development of what are called the powers of nature,--or, to speak more intelligibly, the successive improvements in the habitations intended for higher and higher races of animated life,--and the similarity of plan on which these races were organized, the scheme being preserved in all its essential features through countless generations, show unity of design, and prove that the works of creation, however separated in time, must be attributed to _one_ intelligent author. The same conclusion follows almost irresistibly from the gradations at present observable both in the animal and vegetable kingdoms, so that all the races may be arranged, not indeed in a linear series, but in families or groups, bearing analogous relations to each other, and showing a general progress from the more simple to the more complex forms. Surely, these facts, so clearly explained by our author, instead of sustaining the corpuscular philosophy, directly militate with it, and afford the most satisfactory proof of the doctrine of the theist, and the theory of continuous divine agency. We have hardly ever met with a book that furnished more complete materials for its own refutation.