traced through
the intervening people of the stone age, who were succeeded by the
people of the bronze age, and these by workers in iron.[2] Now,
various evidence carries back the existence of many of the present
lower species of animals, and probably of a larger number of plants,
to the same drift period. All agree that this was very many thousand
years ago. Agassiz tells us that the same species of polyps which are
now building coral walls around the present peninsula of Florida
actually made that peninsula, and have been building there for
centuries which must be reckoned by thousands.

[Footnote 1: See Correspondence of M. Nickles, in _American Journal
of Science and Arts_, for March, 1860.]

[Footnote 2: See Morlet, _Some General Views on Archaeology_, in
_American Journal of Science and Arts_, for January, 1860, translated
from _Bulletin de la Societe Vaudoise_, 1859.]

5. The overlapping of existing and extinct species, and the seemingly
gradual transition of the life of the drift period into that of the
present, may be turned to the same account. Mammoths, mastodons, and
Irish elks, now extinct, must have lived down to human, if not almost
to historic times. Perhaps the last dodo did not long outlive his
huge New Zealand kindred. The auroch, once the companion of mammoths,
still survives, but apparently owes his present and precarious
existence to man's care. Now, nothing that we know of forbids the
hypothesis that some new species have been independently and
supernaturally created within the period which other species have
survived. It may even be believed that man was created in the days of
the mammoth, became extinct, and was recreated at a later date. But
why not say the same of the auroch, contemporary both of the old man
and of the new? Still it is more natural, if not inevitable, to
infer, that, if the aurochs of that olden time were the ancestors of
the aurochs of the Lithuanian forests, so likewise were the men of
that age--if men they were--the ancestors of the present human races.
Then, whoever concludes that these primitive makers of rude flint
axes and knives were the ancestors of the better workmen of the
succeeding stone age, and these again of the succeeding artificers in
brass and iron, will also be likely to suppose that the _Equus_ and
_Bos_ of that time were the remote progenitors of our own horses and
cattle. In all candor we must at least concede that such
considerations suggest a genet