s full of flying-fish and coral
reefs. The northern continent is broadest in the cool latitudes that are
most favorable for human activity. The southern expands most widely in
latitudes whose debilitating monotony of heat and moisture is the
worst of handicaps to human progress. The great rivers of the northern
continent correspond very closely to those of the southern. The
Mackenzie, however, is bound in the rigid bands of winter for eight
months each year, while the Orinoco, the corresponding South American
river, lies sweltering under a tropical sun which burns its grassy
plains to bitter dust even as the sharp cold reduced the Mackenzie
region to barren tundra. The St. Lawrence flows through fertile grain
fields and the homes of an active people of the temperate zone, but the
Amazon winds its slow way amid the malarious languor of vast tropical
forests in which the trees shut out the sky and the few natives are
apathetic with the eternal inertia of the hot, damp tropics.

Only when we come to the Mississippi in the northern continent and
the Rio de la Plata in the southern do we find a pair of rivers which
correspond to any degree in the character of the life surrounding them,
as well as in their physiographic character. Yet even here there is a
vast difference, especially in the upper courses of the river. Each at
its mouth flows through a rich, fertile plain occupied by a progressive,
prosperous people. But the Rio de la Plata takes its rise in one of the
world's most backward plains, the home of uncivilized Indians,
heartless rubber adventurers, and the most rapacious of officials. Not
infrequently, the degenerate white men of these regions, yielding to
the subtle and insidious influence of the tropics, inflict the most
outrageous abuses upon the natives, and even kill them on slight
provocation. The natives in turn hate their oppressors, and when the
chance comes betray them or leave them to perish in sickness and misery.
The upper Mississippi, on the other hand, comes from a plain where
agriculture is carried on with more labor-saving devices than are found
anywhere else in the world. There States like Wisconsin and Minnesota
stand in the forefront of educational and social progress. The contrasts
between the corresponding rivers of the two Americas are typical of the
contrasts in the history of the two continents.

CHAPTER III. THE GEOGRAPHIC PROVINCES OF NORTH AMERICA

The four great physical divisions