My third example from geology, showing the non-eternity of the present condition of the globe, is the fact of the disappearance of several large species of animals since the commencement of the most recent or alluvial geological period. Certain large pachydermatous and other animals, such as the fossil elephant, the mastodon, the megatherium, the mylodon, the megalonyx, the glyptodon, the fossil horse, ox, deer, &c., also nine or ten species of huge birds--the dinornis, the palapteryx, aptornis, notornis, and nestor of New Zealand, the dodo of Mauritius and Bourbon, and the pezohaps or solitaire of Rodriguez,--have ceased to exist since the tertiary period; some of them--the birds, for instance--since man's creation. Now, if any important species of animals from time to time disappear from any system of organic life, it shows a tendency to ruin in that system; for such is the intimate dependence of different beings upon one another, that you cannot blot out one, certainly not a large number, without disturbing the healthy balance between the whole, and probably bringing the whole to ultimate ruin. At any rate, if several species die out by natural processes, no reason can be given why others should not, in like manner, disappear. And to prove that any organic system shows a tendency to ruin is to show that it had a beginning. My third example from geology, demonstrating the special interference of the Deity in the affairs of this world, is the fact of the comparatively recent commencement of the human race. That man was among the very last of the animals created is made certain by the fact that his remains are found only in the highest part of alluvium. This is rarely more than one hundred feet in thickness, while the other fossiliferous strata, lying beneath the alluvium, are six miles thick. Hence man was not in existence during all the period in which these six miles of strata were in a course of deposition, and he has existed only during the comparatively short period in which the one hundred feet of alluvium have been formed; nay, during only a small part of the alluvial period. His bones, having the same chemical composition as the bones of other animals, are no more liable to decay; and, therefore, had he lived and died in any of the periods preceding the alluvial, his bones must have been mixed with those of other animals belonging to those periods. But they are not thus found in a single well-authenticated instance, and, therefore, his existence has been limited to the alluvial period. Hence he must have been created and placed upon the globe--such is the testimony of geology--during the latter part of the alluvial period.