HUMAN REMAINS: NATURE OF THE EVIDENCE. 279 
A sufficient number of these have already been given. We may now pass, 
therefore, to a brief discussion of the facts which have been set forth; and 
this discussion will have to do chiefly with the probable authenticity of the 
mass of evidence taken as a whole, and the question what geological age is 
to be assigned to these various remains. A more general treatment of the 
whole subject, especially from the point of view of the physical conditions 
which have been influential during the later Tertiary times in the Sierra 
Nevada, may be expected in a future chapter. 
In considering all the evidence which has been offered above, a most strik- 
ing thing is its coherence. It all points in one direction. There has never 
been an attempt made — so far as known to the writer, and he has kept his 
eyes pretty widely opened in this direction — to pass off on any member of 
the Survey, when engaged in seeking for proofs of the antiquity of man in 
the mining region, anything out of keeping, or, so to speak, out of harmony, 
with what had been already found, or might be expected to be found. No 
hieroglyphics, ornaments, or implements of any kind, the workmanship of 
which would indicate a high degree of civilization, have ever been offered as 
finds in the auriferous gravel region. It has been always the same kind of 
implements which have been exhibited to us, namely, the coarsest and the 
least finished which one would suppose could be made and still be imple- 
ments at all. Stone mortars are by far the most common and the most strik- 
ing utensils which have been unearthed from the gravel. This may be 
partly due to the size and strength of these articles, which are usually such 
as would enable them to withstand a great amount of hard wear without 
going to pieces. Still, it is difficult to avoid the conclusion that the race 
inhabiting this region in prehistoric times did, for some purpose or other, 
make great use of these utensils. The most natural supposition in regard 
to the mortars is, that they were used for grinding food.. They are not in 
use at present among the Indians of that part of California where the imple- 
ment in question is so abundantly found. The Digger Indians seem now, 
for some unknown reason, to prefer cavities worn in the rock in place, and 
in these the writer has often seen them crushing their acorns; but never 
once has he found them using the portable mortar. 
It is not intended, however, at the present time, to go into any discussion 
of the ethnological relations of the prehistoric race as evidenced by the im- 
plements which have been discovered. All that is desired is to impress upon 
the reader the homogeneous character of the evidence from the point of view 
