on the left bank was _chapada_. Huge gorgeous butterflies
with black-striped brown wings and velvety bodies flew in great numbers
around the canoe. Some settled on my hat, hands, and on the sleeves of my
white shirt. They were so unaccustomed to see human beings that when
touched they did not attempt to fly away.

The river was getting more and more wonderful every hour as we went
along--in great straight lines of 3,500 m., 3,000 m., 2,200 m., 2,000 m.,
4,000 m., in length.

Some ducks rose from the water only a few yards in front of the canoe.
The man who was behind me fired with his carbine close to my head. The
bullet grazed my right ear. It was a trifle trying to be travelling with
such careless sportsmen, but the best thing was to say nothing and go on.

A big island--Passos Island--300 m. long, preceded by a smaller islet 80
m. long--Passos Junior I.--was subsequently passed, where the river
formed a channel (N.W.) 50 m. wide and a minor one (W.) 30 m.

The river there changed from a westerly course to W.S.W. Once more we had
before us a great wall of red rock which at first seemed to bar our way.
In the lower section of the wall was a cave eroded by water and extending
some way back. It was too low to be entered by the canoe. The lower
stratum of the wall was at an angle--in other words, had a dip of
21 deg.--while the stratum above it, 30 ft. in thickness, intersected by a
yellow band, was perfectly horizontal. On the left side of this high
natural wall was a charming waterfall of limpid water. Farther on a great
land-slip displayed for a length of 40 m. brilliant red earth over a
stratum 60 ft. thick of white chalk. The river, which described a number
of turns, was bordered on the left side by a hill range covered with
handsome trees.

The ardour of my men for rowing had already passed away. They smoked and
sang the whole time, and let the current--fortunately strong--carry us
along. Whenever I remonstrated they scooped the water carelessly with
their paddles for a few minutes. As is the case with individuals mentally
deficient, everything seemed to distract them. One moment it was the
flight of a _jacutinga_--a handsome black gallinaceous bird with a white
crest. Another moment it was the jump of an inquisitive fish. Many
_mergulhao commun_ (_Podiceps Americanus_), wonderfully graceful, velvety
black birds with long beaks, flew about unconcerned from tree to tree.
Whenever anything moved about anywhere, t