First invertebrate life, then the lowest forms of vertebrate
life. The fishes are followed by amphibians--then reptiles, then
birds. The first mammal to appear was the lowest organized of
all--the marsupials. And we have seen the sudden increase of
mammalian life in Tertiary times. We notice, in all the
divisions of life, a beginning, a culmination, and a decline.
There has never been such a growth of flowerless plants as in
the Paleozoic, and flowering plants probably culminated in the
Miocene. The same rule holds good for the animal world also.
As man is the most highly organized of all the animals, we can
not hope to find any evidence of his presence until we find
proofs of the presence of all the lower types of life. Of course
future discoveries may change our knowledge when the series is
complete; but, from our present stand-point, he could not have
lived before the Miocene Age, and we have seen how faint and
indecisive are the proofs of his presence even then. But should
it finally be proved, beyond all dispute, that man did live in
the Miocene Age, we must observe that this is but a small
portion, but a minute fraction, of the great lapse of time since
life appeared on the globe. We are a creation of but yesterday,
even granting all that the most enthusiastic believer in the
antiquity of man can claim.

Illustration of The Mastodon.-------------


REFERENCES

(1) The manuscript of this chapter was submitted to Prof.
Winchell, of the University of Michigan, for criticism.