ACROSS UNKNOWN SOUTH AMERICA 
mouth, entered the Arinos, from the west-southwest at this 
point. Its water was deliciously clear. A little way off 
to the left we could hear the noise of a waterfall on the 
Sumidoro, before it joined the Arinos. 
The river, after the meeting of this important tribu¬ 
tary, became even more exquisitely beautiful than before. 
Rocks strewn about added to the picturesqueness of the 
landscape as well as to the dangers of navigation, while 
springs of crystalline water, cool and quite delicious to 
drink, descended here and there from the banks. 
The river had an average width of sixty metres in 
this part, and was much strewn with broken-up volcanic 
boulders, especially on the left bank. On the right bank 
was a beach of immaculate white sand. For 300 metres 
we went over a great stony place with shallow water. We 
had to be careful, but all the same many times did we 
bump with great force and get stuck upon submerged 
rocks, which we could not see owing to the blinding, 
glittering refraction of the sun upon the troubled waters. 
A tributary four metres wide, coming from the north¬ 
east, entered the Arinos on the right bank. A great 
number of rubber trees were to be seen on the right bank, 
where the forest was luxuriant; but not on the left bank, 
where the growth of trees was scanty. Caranda or burity 
or tucuman palms were plentiful along the water’s edge 
near the spot where a small rivulet entered the Arinos on 
the left bank. Two thousand metres farther down we 
came upon denuded country, low, and liable to inundation 
when the river rose. Farther on were campos and open 
country, with the exception of a thin row of trees imme¬ 
diately along the river. On the left we had luxuriant 
forest, wonderfully healthy, neat, and clean. The stream 
was there beautiful, 60 to 70 metres wide. 
When we had gone 10 kilometres 800 metres more 
the entire channel became strewn with rocks and mounds 
only one foot below the surface of the water, and not 
46 
