262 NOTES OF A BOTANIST 
had ascended also the Rio dos Cauabon's and the 
Marauia (both of which have their rise in the same 
lofty serras), and there encountered with Indians 
from the sources of the Orinoco, who had come 
by a short portage. According to him, there are 
several cataracts on the Orinoco above Esmeralda, 
but they cannot be compared to those of Atures and 
Maypures. He knew Natterer when on the Rio 
Negro. Natterer ascended the rather low serras 
in front of Castanheiro. 
Dec. 1 6. — Not a puff of wind to aid us to-day. 
After passing some trifling rapids, we arrived a little 
before sunset at the foot of a series so formidable 
that it was deemed prudent to wait for the morning 
before attempting their passage. They are called 
Jurupari-roka (the Devils house), but possibly this 
appellation is derived from a large mass of granite 
rising with a gentle slope on the left of the falls to 
a height of some 40 feet, of a very sooty hue and 
having near the top several deep hollows. I climbed 
to the summit just after the sun had set and had 
a very fine view. Beneath me were the rapids 
tumbling among masses of granite with a noise 
which we had heard an hour before reaching them. 
Then spread out the glorious river, empurpled with 
the rays of the departed sun, shining through the 
interstices of five large wooded islands ; while 
numerous shapeless blocks of granite stood out of 
the river here and there, some naked, others with a 
scanty vegetation in their clefts ; the waters every- 
where circling and eddying or running rapidly over 
some sunken ledge of rock. At my back I had 
dense low forest showing numerous types of foliage 
near to me and varied by the overtopping crown of 
