In the case of the discovery at Newcomerstown, Mr. Holmes is peculiarly unfortunate in his efforts to present the facts, since, in endeavouring to represent the conditions under which the implement was found by Mr. Mills, he has relied upon an imaginary drawing of his own, in which an utterly impossible state of things is pictured. The claim of Mr. Holmes in this case, as in the other, is that possibly the gravel in which the implements were found had been disturbed. In some cases, as in Little Falls and at Madison ville, he thinks the implements may have worked down to a depth of several feet by the overturning of trees or by the decay of the tap-root of trees. A sufficient answer to these suggestions is, that Mr. Holmes is able to find no instance in which the overturning of trees has disturbed the soil to a depth of more than three or four feet, while some of the implements in these places had been found buried from eight to sixteen feet. Even if, as Mr. Chamberlin suggests,[Z] fifty generations of trees have decayed on the spot since the retreat of the ice, it is difficult to see how that would help the matter, since the effect could not be cumulative, and fifty upturnings of three or four feet would not produce the results of one upturning of eight feet. Moreover, at Trenton, where the upturning of trees and the decaying of tap-roots would have been as likely as anywhere to bury implements, none of those of flint or jasper (which occur upon the surface by tens of thousands) are buried more than a foot in depth; while the argillite implements occur as low down as fifteen or twenty feet. This limitation of flint and jasper implements to the surface is conclusively shown not only by Dr. Abbott's discoveries, but also by the extensive excavations at Trenton of Mr. Ernest Volk, whose collections formed so prominent a part of Professor Putnam's Palæolithic exhibit at the Columbian Exposition at Chicago. In the village sites explored by Mr. Volk, argillite was the exclusive material of the implements found in the lower strata of gravel. Similar results are indicated by the excavations of Mr. H. C. Mercer at Point Pleasant, Pa., about twenty miles above Trenton, where, in the lower strata, the argillite specimens are sixty-one times more numerous than the jasper are. [Footnote Z: American Geologist, vol. xi, p. 188.]