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 

 heds where the fossil leaves descrihed 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." 1 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 Carpinus, 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. 2. r i0 - 252. 



