And here it may be necessary to explain, that the geological term Tertiary comprises all the strata that have been deposited subsequently to the last secondary formation, the Chalk. The Tertiary systems, therefore, unite the present organic kingdoms of nature with the past; for while the most ancient, the Eocene deposits, contain the remains of a few secondary species, they have likewise many of genera now existing, associated with peculiar types.
But notwithstanding the occurrence of bones of living genera of animals—as the dog, fox, pig, sheep, ox, horse, &c.,[1] in tertiary strata, incomparably more ancient than the deposits containing the Irish Elk, yet no vestiges of man or of his works have been detected.
The proofs adduced of the remarkable characters impressed on the deposits that have been formed since the various races of mankind were distributed over the earth's surface, forbid the supposition that the absence of such vestiges can be attributable to their subsequent obliteration. While, therefore, we may reasonably expect to find fossil human remains in strata of much higher antiquity than those in which they have hitherto been observed, it does not seem probable that traces of man's existence will be met with in the most ancient tertiary formations.
It was for the express purpose of placing this fact in the most striking point of view, that, in a previous part of this discourse, I dwelt somewhat at length on the nature and organic remains of the deposits that have been accumulated during the human epoch. Notwithstanding, therefore, the occurrence in the Eocene system of existing genera and species of mammalia—even of that race which approaches nearest to man in its physical organization, the Quadrumana, or monkey tribes—I conceive we have no just grounds for assuming that physical evidence will be obtained, by which the existence of the human race, and consequently of the present order of things, may be traced back to that remote era; for I entirely concur in the opinion expressed by Professor Whewell, "that the gradation in form between man and other animals, is but a slight and unimportant feature in contemplating the great subject of man's origin. Even if we had not revelation to guide us, it would be most unphilosophical to attempt to trace back the history of man, without
- ↑ See Wonders of Geology, vol. i., p. 215.
