s of the Xingu, Tapajos and Guapore on the
north and west, the Paraguay on the south-west, and the scores of
smaller rivers along the Atlantic coast, and we may have some
conception of the agencies that have been at work in breaking down and
shaping this great table-land, perhaps the oldest part of the
continent. The most southern of these _chapadoes_, that of the Parana
basin, in which may be included the northern part of the Uruguay and
eastern part of the Paraguay basins, includes the greater part of the
states of Rio Grande do Sul, Santa Catharina, Parana and Sao Paulo,
the south-western corner of Minas Geraes, a part of southern Goyaz,
and the south-eastern corner of Matto Grosso. The greatest elevation
is on its eastern or Atlantic margin where the average is about 3280
ft. above sea-level. The plateau breaks down abruptly toward the sea,
and slopes gradually some hundreds of feet toward the south and west.
There has been considerable denudation toward the west, the eastern
tributaries of the Parana rising very near the coast. The northern and
western parts of this plateau have an average elevation a little less
than that of the Atlantic margin, and their slopes are toward the
south and east, those of Goyaz and Matto Grosso being abrupt and
deeply eroded. This great _chapadao_ is in many respects the best part
of Brazil, having a temperate climate, extensive areas of fertile
soil, rich forests and a regular rainfall. Its Atlantic slopes are
heavily wooded, but the western slopes exhibit grass-covered _campos_
between the river courses. The Sao Francisco _chapadao_, which has a
general elevation of about 2600 ft., covers the greater part of the
states of Minas Geraes and Bahia, and a small part of western
Pernambuco, and might also be considered continuous with those of the
Parnahyba and Tocantins-Araguaya basins. This region is more tropical
in character, partially barren, and has an uncertain rainfall, a large
part of the Sao Francisco basin and the upper Atlantic slope of its
eastern rim being subject to long-continued droughts. This region is
well wooded along the river courses of Minas Geraes, the lower
Atlantic slopes of Bahia, which are perhaps outside the plateau
proper, and on the weather side of some of the elevated ridges where
the rainfall is heavy and regular. It has extensive _campos_ and large
areas of exposed rock and stony steppes,