But at the same time he finds in southern Europe abundant remains of polar animals which could only have lived when the everlasting snow and ice of a frigid clime covered the surface of those now sunny lands. Still finding rude stone implements, the work of human hands, mingled with these polar skeletons, he adds to the result of previous computations the time deemed necessary for so essential a climatic transformation, and, finally, he is driven to make still another addition, when he learns that in geologic strata much older than any yet considered, the bones and works of man have been discovered in several apparently well-authenticated instances lying side by side with the bones of mastodons and other ancient species which have long since disappeared from the face of the earth. With the innumerable data of which the foregoing is only an outline before him, the student of man's antiquity is left to decide for himself whether or not he can satisfactorily compress within the term of sixty centuries all the successive periods of man's development. In our examination of relics in the thinly peopled Pacific States we shall find comparatively few works of human hands bearing directly on this branch of archæology; yet in the north-west regions, newest to modern civilization, the Californian miner's deep-sunk shafts have brought to light implements and fossils of great antiquity and interest to the scientific world. * * * * * [Sidenote: AMERICAN RELICS AND HIEROGLYPHICS.] In America many years must elapse before explorations equaling in extent and thoroughness those already made in the old world can be hoped for. The ruins from whose examination the grandest results are to be anticipated lie in a hot malarious climate within the tropics, enveloped in a dense thicket of exuberant vegetation, presenting an almost impenetrable barrier to an exploration by foreigners of monuments in which the natives as a rule take no interest. It must be admitted, however, that even the most exhaustive examination of our relics cannot be expected to yield results as definite and satisfactory as those reached in the eastern continent. We have practically no written record, and our monuments must tell the tale of the distant past unaided.