38 FOSSIL FLORA OF THE SIERRA NEVADA. 
GENERAL CONCLUSIONS. 
In the first volume of the Geological Report of California, Professor 
J. D. Whitney, considering the age of the auriferous gravel and clay 
beds where the fossil leaves described above have been obtained, says 
that, from the determination of a quantity of bones and teeth found in 
this formation, it appears referable to the Pliocene. “ Among them, remains 
of the rhinoceros, of an animal allied to the hippopotamus, an extinct spe- 
cies of horse, and a species allied to the camel had been recognized.”’ He 
also adds, as a confirmation of his conclusions, “that the works of man 
have been so frequently found among the recent deposits of the aurifer- 
ous gravel, and in such connection with the bones of the mastodon and 
elephant, that it is hardly possible to escape the inference that the human 
race existed before the disappearance of these animals from the region 
which was once thickly inhabited by them.” 
Professor Whitney remarks on the same question, that a few speci- 
mens of the leaves of Buckeye-Tunnel, Tuolumne County, were forwarded 
to Professor Newberry, who made a preliminary investigation of them 
and furnished some notes of its results, authorizing the conclusions that 
these stratified deposits under the lava of Table Mountain are of Ter- 
tiary age, and that in all probability they belong to the later Pliocene 
epoch. Professor Newberry writes that “the leaves submitted to him 
are quite different from those of any trees now living in California, and 
that they are specifically distinct from those of the Miocene Tertiaries of 
Oregon, Nebraska, or of any other part of the continent. They include 
Tertiary and recent genera, such as Acer and Curpinus, and are there- 
fore not older than the Miocene.” 
In 1872 Professor Whitney sent me from California a large number of 
specimens of fossil plants, part of which — those from the auriferous depos- 
its of Tuolumne and Nevada counties—represent the species described 
above. The other half of the collection consists of specimens mostly from 
1 Geological Survey of California. Geology, Vol. I. pp. 250 — 252. 
