APPENDIX. 373

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 Palaeolithic,
but Neolithic.'''' * The question has been raised whether this
archaeological objection is applicable to the stone mortars,
numerous examples of which have been found in the gravels,
some of them quite recently.f If the evidence brought for-
ward by Professor Whitney and others were limited to
these mortars, it might very well be claimed that they are
neither Palaeolithic 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.
