and trees.

_Plants._ The vegetation in the early part of the era was very
different both from the gloomy forests of the more ancient Coal Era
and from that which prevails today. Cycads, ferns and fern-like
plants, coniferous trees, especially related to the modern
_Araucaria_ or Norfolk Island Pine, Ginkgos still surviving in China,
and huge equisetae or horsetail rushes, still surviving in South
American swamps and with dwarfed relatives throughout the world, were
the dominant plant types of that era. The flowering plants and
deciduous trees had not appeared. But in the latter half of the era
these appeared in ever increasing multitudes, displacing the lower
types and relegating them to a subordinate position. Unlike the more
rapidly changing higher animals these ancient Mesozoic groups of
plants have not wholly disappeared, but still survive, mostly in
tropical and southern regions or as a scanty remnant in contrast with
their once varied and dominant role.

There is every reason to believe that upon the appearance of these
higher plants whose flower and fruit afforded a more concentrated and
nourishing food, depended largely the evolution of the higher animal
life both vertebrate and insect, of the Cenozoic or modern era.

FOOTNOTES:

[Footnote 1: The records of Egypt and Chaldaea extend back at least
sixty centuries.]

CHAPTER II.

NORTH AMERICA IN THE AGE OF REPTILES.

ITS GEOGRAPHIC AND CLIMATIC CHANGES.

North America in the Age of Reptiles would have seemed almost as
strange to our eyes in its geography as in its animals and plants. The
present outlines of its coast, its mountains and valleys, its rivers
and lakes, have mostly arisen since that time. Even the more ancient
parts of the continent have been profoundly modified through the
incessant work of rain and rivers and of the waves, tending to wear
down the land surfaces, of volcanic outbursts building them up, and of
the more mysterious agencies which raise or depress vast stretches of
mountain chains or even the whole area of a continent, and which tend
on the whole so far as we can see, to restore or increase the relief
of the continents, as the action of the surface waters tends to bring
them down to or beneath the sea level.

_Alternate Overflow and Emergence of Continents._ In a broad way these
agencies of elevation and of erosion have caused in their age-long
struggle an alternation of periods of overflow and periods of
continent