THE ANTIQUITY OF MAN AND THE ORIGIN OF SPECIES. 531 
sided presentation of facts so common with the more advanced advocates of the 
‘doctrine. Perhaps we may most clearly present the salient points brought out in 
these works by noticing first the successive Tertiary periods and their life, cul- 
minating in the introduction of man, and secondly the facts as to the introduction 
of those earlier creatures which swarmed in the Paleozoic seas. 
The Tertiary or Kainozoic period, the last of the four great ‘‘ times” into 
which the earth’s geological history is usually divided, and that to which man 
and the mammalia belong, was ingeniously subdivided by Lyell, on the ground 
of percentages of marine shells and other invertebrates of the sea. .\ccording to 
this method, which with some modification in details is still accepted, the Zocene, 
or dawn of the recent, includes those formations in which the percentage of 
modern species of marine animals does not exceed 3%, all the other species 
found being extinct. The Mzocene (less recent) includes formations in which the 
percentage of living species does not exceed 35, and the /izocene (more recent) 
contains formations having more than 35 per cent of recent species. To these 
three may be added the Pleistocene, in which the great majority of the species are 
recent, and the Modern, in which all may be said to be living. Dawkins and 
Gaudry give us a division substantially the same with Lyell’s, except that they 
prefer to take the evidence of the higher animals instead of the marine shells. 
The Eocene thus includes those formations in which there are remains of mam- 
mals or ordinary land quadrupeds, but none of these belong to recent species or 
genera, though they may be included in the same families and orders with the 
recent mammals. This is a most important fact, as we shall see, and the only 
exception to it is that Gaudry and others hold that a few living genera, as those 
of the dog, civet, and marten, are actually found in the later Eocene. In the 
case of plants, as we shall find, Saporta shows that modern genera of land plants 
occur before the Eocene, in the last great group of the preceding period, and we 
have abundant American evidence of the same fact. As in the Mosaic narrative 
of creation, the higher plants precede by a long time the higher animals. The 
Miocene, on the same mammalian evidence, will include formations in which 
there are living genera of mammals, but no species which survive to the present 
time. ‘The Pliocene and Pleistocene show living species, though in the former 
these are very few and exceptional, while in the latter they become the majority. 
With regard to the geological antiquity of man no geologist expects to find 
any human remains in beds older than the Tertiary, because in the older periods 
the conditions of the world do not seem to have been suitable to man, and be- 
cause in these periods no animals nearly akin to man are known. On entering 
into the Eocene Tertiary we fail in like manner to find any human remains; and 
and we do not expect to find any, because no living species and scarcely any 
living genera of mammals are known in the Eocene; nor do we find in it remains 
of any of the animals, as the anthropoid apes for instance, most nearly allied to 
man. In the Miocene the case is somewhat different. Here we have living gen- 
