flowing north into the Paraguay River, and shortly
afterwards to the Caitte and the Corisho (elev. 1,500 ft.). They were the
three real and true sources of the Paraguay, within a short distance of
the Seven Lakes.

We had marched 50 kil. that day over rough country. My animals were quite
exhausted. Yet early next morning we pushed on once more over transverse
undulations and across grassy _cuvettes_, slightly conical, with
circular pools of water in the centre and a florid growth of bamboos in
the lowest point of the _cuvettes_. We ascended over more dyke-like
obstructions on our way (elev. 1,700 ft.) and descended once more into a
vast basin of campos with stunted trees. At its lowest point there was
from north-east to south-west a line of magnificent tall trees. The
forest was so dense there that when we entered it we were quite in the
dark, as if going through a tunnel. There were fine specimens of various
kinds of the _jua_ or _juaz_ or _jurubeba_ (solanum), a medicinal plant 5
to 6 ft. high with enormous dentate leaves--shaped not unlike a vine
leaf--possessing upright spikes on their dorsal or mid-rib and on the
veins of the leaf.

Then there was plentiful "_cepa de pappo_," a common liana like a huge
boa-constrictor winding its way in a spiral up the tallest trees. I saw
some of those liane 3 in. in diameter, with a smooth whitish bark.

The soil at the bottom of the valley (1,500 ft. above sea level) was
mostly composed of cinders, but up the slopes white sand was predominant,
mixed with ashes. We travelled over a lava flow which formed the bed of
the River Macucu, flowing eastward. Guided by the noise, we found a most
beautiful waterfall, 100 ft. high, over an extinct circular crater with
vertical walls. We kept on rising over a gentle incline, and having
reached an elevation of 1,750 ft. we found ourselves suddenly on the
upper edge of a great crescent-shaped depression extending in a
semicircle from north-east to south-west. Its walls were one-tiered to
the west, with a flat table-land on their summit, but were divided into
two terraces in the northern part where ranges of hills rose on the
plateau.

We had a rapid, steep descent among great rectangular blocks of
conglomerate (white marble pebbles embedded in iron rock), great sheets
of lava, and sediments of red earth, solidified in places into
half-formed rock. I noticed extensive lava flows which had run towards
the west; then we came upon extraordinar