erhaps there are people in the world who might
cultivate such a region and raise marvelous crops, but they are not the
indolent people of tropical America; and it is in fact doubtful whether
any kind of people could live permanently in the tropical forest and
retain energy enough to carry on cultivation. Nowhere in the world is
there such steady, damp heat as in these shadowy, windless depths
far below the lofty tops of the rain forest. Nowhere is there greater
disinclination to work than among the people who dwell in this region.
Consequently in the vast rain forests of the Amazon basin and in
similar small forests as far north as Central America, there are today
practically no inhabitants except a mere handful of the poorest and most
degraded people in the world. Yet in ancient times the northern border
of the rain forest was the seat of America's most advanced civilization.
The explanation of this contradiction will appear later. *

* See Chapter 5, Aztecs.

Tropical jungle borders the rain forest all the way from southern Mexico
to southern Brazil. It treats man far better than does the rain forest.
In marked contrast to its more stately neighbor, it contains abundant
game. Wild fruits ripen at almost all seasons. A few banana plants and
palm trees will well-nigh support a family. If corn is planted in a
clearing, the return is large in proportion to the labor. So long as
the population is not too dense, life is so easy that there is little to
stimulate progress. Hence, although the people of the jungle are
fairly numerous, they have never played much part in history. Far more
important is the role of those living in the tropical lands where scrub
is the prevailing growth. In our day, for example, few tropical lowlands
are more progressive than the narrow coastal strip of northern Yucatan.
There on the border between jungle and scrub the vegetation does not
thrive sufficiently to make life easy for the chocolate-colored natives.
Effort is required if they would make a living, yet the effort is not
so great as to be beyond the capacity of the indolent people of the
tropics.

Leaving the forests, let us step out into the broad, breezy grass-lands.
One would scarcely expect that a journey poleward out of the forest of
northern Canada would lead to an improvement in the conditions of human
life, yet such is the case. Where the growing season becomes so short
that even the hardiest trees disappear, grassy tundr