Page:Popular Science Monthly Volume 43.djvu/338

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the evidence of Glacial man. Many of them had committed themselves to it, and yet when better evidence was brought they were willing to withdraw opinions previously affirmed. The writer himself has entertained a belief in the existence of Glacial man, and there is still some evidence in California that has not yet been examined by the new methods, and it may be that this evidence is good. The writer has much linguistic material that points to the high antiquity of man on this continent. So we will all withhold final judgment until the evidence is in, being perfectly willing to believe in Glacial man, or Tertiary man, or Cretaceous man, if the evidence demands it, and being just as willing to believe that man was introduced on this continent within the last two thousand years, if the evidence demands it. What care we what the truth is, if it is the truth?

Some years ago Mr. McGee found in a lake formation of the West a stone implement, like those still made by the Indians of that country, in beds of an age not greatly differing from those of the gravels of the Eastern shore; and he published his find. In after years he had learned to distinguish overplacement from foundation formation, and he questioned his own conclusions. This was before the present controversy arose, before Mr. Holmes had so skillfully trenched the hills and shown the true age of the stone implements of the Atlantic slope; but still Mr. McGee, warned by his own observations of the difference between overplacement and under-formation, concluded that he might have been too hasty, and published a long article on the subject, from which the following extract is made:

"It is a fair presumption that any unusual object found within, or apparently within, an unconsolidated deposit is an adventitious inclusion. Every cautious field geologist accustomed to the study of unconsolidated superficial deposits quickly learns to question the verity of apparently original inclusions; he may, it is true, exhaust the entire range of hypothesis at his command without satisfying himself that the inclusion is adventitious; yet he is seldom satisfied that he has exhausted the range of possible hypothesis as to the character of the inclusion, and hesitates long before accepting any unusual association as veritable. His case is not that of the invertebrate paleontologist at work in the Palæozoic rocks, to whom a single fossil may carry conviction; for not only are the possibilities of adventitious inclusion indefinitely less in solid strata, but the mineral character of the fossil is commonly identical with that of its matrix, and so affords inherent evidence of the verity of the association. Nowhere, indeed, in the entire range of the complex and sometimes obscure and elusive phenomena of geology is there more reason for withholding final judgment based upon unusual association than in the