Necessity of a general acquaintance with the outlines of Geology--A
time in which there was no life possible on the globe--Length of this
period--On the formation of rocks--The record imperfect--The three great
periods in animal life on the globe--Paleozoic age--Animal and vegetable
life of this period--The Mesozoic age--Animal and vegetable life of this
period--Advance noted--Abundance of reptilian life--First appearance
of birds--Nature's methods of work--The Cenozoic age--Geological
outline--Sketch of the Eocene age--Of the Miocene age--What is
sufficient proof of the presence of man--Discussion of the Thenay
flints--The Pliocene age--Animal and vegetable life of this age--Was
man living during this age?--Discussion of this subject--Summing up the
evidence--Conclusion.

For a clear understanding of questions relating to early man, a more
or less extensive acquaintance with Geology is required. This is by
no means a difficult task to accomplish. What so interesting as to
understand at least the outlines of the history of life on the globe?
To see how, following a definite plan, the vast continents have grown to
their present size and form; to see how animal and vegetable life have
evolved successively higher and higher forms; to see where in this
wondrous drama of creation, this strange unfolding of life, the first
faint, indecisive traces of man's presence are to be found; to learn
what great changes in climate, in Geogony, and in life, had occurred
before man's appearance, let us pass in brief review the history of
early geological periods.

As we have already stated, there must have been a very long period of
time during which no life was possible on the globe. Of this era we know
but little; for we find no strata of rocks of an earlier date than we
know life, in its simplest forms, to have existed.<2> Still we are not
less confident of the existence of this era, and the mind can dimly
comprehend the scene, when a nearly shoreless ocean surged around the
globe.<3>

As to the extent of time during which there was no life, we have
no means of determining. That it was almost infinitely long is made
apparent by the researches of eminent scholars on the cooling of lava.
Toward the close of this extended period of time faint traces of life
appear. Not life as we are apt to think of it. No nodding flowers
were kissed by the sunshine of this early time. The earliest forms of
flowerless plants, such as sea-weeds, a