still going on, though in a greatly modified form.

I cannot leave this Serra without alluding to the great beauty and
extraordinary extent of the view to be obtained from it. Indeed, it was
here that for the first time the geography of the country presented
itself to my mind as a living reality, in all its completeness.
Insignificant as is its actual height, the Serra of Errere commands a
wider prospect than is to be had from many a more imposing mountain; for
the surrounding plain, covered with forests, and ploughed by countless
rivers, stretches away for hundreds of leagues in every direction,
without any object to obstruct the view. Standing on the brow of the
Serra, with the numerous lakes intersecting the low lands at its base,
you look across the Valley of the Amazons, as far as the eye can reach,
and through its midst you follow for miles on either side the broad
flood of the great river, carrying its yellow waters to the sea. As I
stood there, panoramas from the Swiss mountains came up to my memory,
and I fancied myself standing on the Alps, looking across the plain of
Switzerland, instead of the bed of the Amazons, the distant line of the
Santarem hills on the southern bank of the river, and lower than the
northern chain, representing the Jura range. As if to complete the
comparison, I found Alpine lichens growing among cactus and palms, and a
crust of Arctic cryptogamous growth covered rocks, between which sprang
tropical flowers. On the northern flank of this Serra I found the only
genuine erratic boulders I have seen in the whole length of the
Amazonian Valley, from Para to the frontier of Peru, though there are
many detached masses of rock, as, for instance, at Pedreira, near the
junction of the Rio Negro and Rio Branco, which might be mistaken for
them, but are due to the decomposition of the rocks in place. The
boulders of Errere are entirely distinct from the rock of the Serra, and
consist of masses of compact hornblende.

It would seem that these two ranges skirting a part of the northern and
southern banks of the Lower Amazons are not the only remnants of this
arenaceous formation in its primitive altitude. On the banks of the
Japura, in the Serra of Cupati, Major Coutinho has found the same beds
rising to the same height. It thus appears, by positive evidence, that
over an extent of a thousand miles these deposits had a very
considerable thickness in the present direction of the valley. How far
they