These are all the localities in Europe claimed by Mortillet to have furnished such evidence, but he thinks a strong confirmation of it is afforded by certain discoveries made in the auriferous gravels of California. I will not occupy space here in repeating arguments I have brought forward elsewhere to show the utter insufficiency of this evidence to prove the existence of man on the Pacific coast of our continent during the Pliocene period,[FJ] They may all be summed up in the words of Le Conte: "The doubts in regard to this extreme antiquity of man are of three kinds, viz.: 1. Doubts as to the Pliocene age of the gravels--they may be early Quaternary. 2. Doubts as to the authenticity of the finds--no scientist having seen any of them in situ. 3. Doubts as to the undisturbed conditions of the gravels, for auriferous gravels are especially liable to disturbance. The character of the implements said to have been found gives peculiar emphasis to this last doubt, _for they are not Paleolithic_, but Neolithic."[FK] The question has been raised whether this archæological objection is applicable to the stone mortars, numerous examples of which have been found in the gravels, some of them quite recently.[FL] If the evidence brought forward by Professor Whitney and others were limited to these mortars, it might very well be claimed that they are neither Palæolithic nor Neolithic; that the smoothness of their surface is owing to their having been hollowed out of pebbles that have been polished and worn by natural forces. But Professor Whitney has cited numberless instances of "spear-heads," "arrow-heads," "discoidal stones," "stone beads," and "a hatchet" that have been found under precisely similar conditions as the mortars. So Mr. Becker has recently produced an affidavit of a certain Mr. Neale that in a tunnel run into the gravel in 1877 "between two hundred and three hundred feet beyond the edge of the solid lava, he saw several spear-heads nearly one foot in length."[FM] Now it cannot be questioned that such objects as these clearly belong to the Neolithic period, which does not imply that all the objects used at that time were polished, but that together with chipped implements "polished stone implements were also used."[FN] No archæologist will believe that, while Palæolithic man has not yet been discovered in the Tertiary deposits of western Europe, the works of Neolithic man have been found in similar deposits in western America. Peculiar difficulties seem to surround the evidence brought forward in support of such an assumption. We are told by Professor Whitney that a stone mortar was "found standing upright, and the pestle was in it, in its proper place, just as it had been left by the owner." He fails, however, to explain how this was brought about in a gravel deposit supposed to have been laid down by great floods of water. So, when Mr. Neale swears that he saw fifteen years ago in the same gravels