346 KANSAS CITY REVIEW OF SCIENCE. 
which he is now surrounded made their appearance. We cannot imagine him to 
have been living in the Eocene age, when animal life was not sufficiently differ- 
entiated to present us with living genera of placental mammals. Nor is there 
any probability of his having appeared on the earth in the Miocene, because of 
the absence of placental mammals belonging to living species. It is most unlikely 
that man should appear in a fauna in which there was no other living mammal. 
He belongs to a more advanced stage of evolution than that presented by the 
mid-Miocene of Thenay, in which flint splinters fashioned by man are said to 
have occurred. Up to this time, the evolution of the animal kingdom had ad- 
vanced no farther than the Simiadce in the direction of man, and the apes then 
haunting the forests of Italy, France and Germany were the most highly organ- 
ized types. We may also look at the question from another point of view. If 
man were upon the earth in the Miocene age, it is incredible that he should not 
have become something else while those changes were going on in the conditions 
of life by which all the Miocene land mammalia have been so profoundly affected 
that they have either assumed new forms or been exterminated. It is impossible 
to believe that man should have been an exception to the law of change. Nor in 
the succeeding Pliocene age can we expect to find traces of man upon the earth. 
The living placental mammals had only then begun to appear, and seeing that 
the higher animals have invariably appeared in the rocks according to their place 
in the zooological scale, Fishes, Amphibians, Reptiles, Placental Mammals, it is 
hardly reasonable to suppose that the highest of all should then have been upon 
the earth. The few scored bones in the PHocene strata of Italy, referred by 
Prof. Capelini to the work of Pliocene man, are considered by Evans and Mort- 
illet to have been marked by the teeth of the large sharks abundant in those seas. 
and if they be artificial it is not, in my opinion, proved that they were marked 
in the PHocene age. " The fossil man of Denise " is of uncertain age, and other 
alleged cases of Pliocene man in Europe have now been given up. 
The question has however been revived in the United States by Prof. Whit- 
ney, in his work on the Auriferous Gravels of California, and the existence of 
inan in California, in the Pliocene age, has been accepted by such high authorities 
as Marsh, LeConte, and others. It becomes, therefore, necessary for us to see 
how the facts will stand the test of criticism. In the first place it is assumed that 
the auriferous gravels in the Sierras, with traces of man, which are in some places 
three hundred feet thick, and sometimes covered with ancient lava streams, are 
of Pliocene age. They are, however, proved by their fossils, identified by Dr. 
Leidy, to have been deposited by the streams from the Miocene {Elotherium) age 
down to the present time. Among the animals we may note the skull of a mus- 
tang, identical with that of Mexico and California, which could not have been 
buried in the gravels of Sierra County before the time of the Spanish conquest, 
when the living race of horses was introduced. Consequently, the discovery of 
human remains in the auriferous gravels does not prove that man was an inhabi- 
tant of Pliocene America, even if it be allowed that they are of the same age as the 
strata in which they lie. There is, however, no evidence of this in any one instance. 
