mation in the extensive valley adds its
tribute, these banks are a kind of mineralogical collection, which shows
samples of all the rocks on the river-banks, with the exception,
perhaps, of light pumice-stone, the produce of the volcanoes of the
Andes, which drifts down-stream in large pieces, and is highly prized by
the Tapuia population (on the lower course) for sharpening and cleaning
their weapons and tools. Even when not picked up by hunter or fisher, it
is not lost. It will be arrested by some snag or projection of the
shore, it will so get embedded in the newly-forming sediment, and
thousands of years hence its silicic acid will afford the necessary
material for the hard glassy bark of a bambusacea, or the sharp edge of
a reed. When the currents are not strong enough to move the larger
banks, they at least carry sand and earth with them, and deposit them as
shoals or new alluvion at less exposed spots....

The undermined concave shores are sometimes a serious danger to the
passing barque, as even the slight ripple of a canoe is sufficient to
bring down the loosely overhanging earth, often covered with gigantic
trunks. These concave sides, with their fallen trees and their clusters
of sinking javary-palms, supported sometimes by only a tangled net-work
of tough lianas, give to the scenery that peculiar character of primeval
wildness which is so charming to foreigners.

When one has climbed up the steep shore, often forming huge terrace-like
elevations, and has safely passed through a labyrinth of interwoven
roots and creepers into the interior of the forest, which is getting
freer from underwood at some distance from the river, he is oppressed
with the sensation of awe and wonder felt by man on entering one of the
venerable edifices of antiquity.

A mysterious twilight encompasses us, which serves to intensify the
radiance of the occasional sunbeam as it falls on a glossy palm-leaf, or
on a large bunch of purple orchid-flowers. Splendid trunks, some of them
from twenty to thirty feet in diameter, rise like so many pillars
supporting the dense green vault of foliage; and every variety of tall,
graceful palms, spare and bushy, and bearing heavy berries of bright
yellow or red, struggle to catch a glimpse of the light, from which they
are shut out by the neighboring giants, of which the figueira (or wild
fig-tree) is one of the most striking, in the dimensions of its crown
and stem, and in the strange shape of its