A streamlet 3 m. wide entered the Arinos on the left. We got to one point where the river proved treacherous, although apparently almost tranquil on the surface. The Brazilians have an excellent name for such places—rebojo, or a curve formed by sudden deviation of a current. If we had not been careful in going across such places, it would have been easy for the canoe to have been turned over and sucked under.
Patches of thick forest were met on either bank, and in those patches numerous indeed were the rubber trees. In the afternoon we saw chiefly campos and chapada, or thin scrub.
Considering all, we did well—chiefly owing to the strong current—on our first day of navigation. We had gone some 70 kils. when we halted at sunset, at the junction of the very deep streamlet Quarustera with the Arinos. The elevation of our camp, 60 ft. above the river, was 1,200 ft.
The nights were cool enough—minimum 55° Fahr. on the night of June 6th—7th. There was a thick haze over the river in the morning, and as we did not know what we might be coming upon suddenly we did not make a start until 7.15. After crossing a large and shallow bay the stream was forced into a channel 50 m. wide. There was open country—campos—on the right bank. A curious isolated volcanic boulder split in two was then observed in the stream, while the banks were of alluvially deposited conglomerate. From that spot luxuriant forest was on the right bank once more, while open country was on the left. Upon examination I found that the thick forest was merely a band or zone near the water—behind was open country.
Farther, the river went through a neck 40 m. wide where the current was very swift. The banks almost all along were from 10 to 20 ft. high. Slender tucuma or tucuman palms were to be seen, which had stems only 3 to 4 in. in diameter, but were 30 to 40 ft. high, and had a ball-like tuft of leaves at the top. We then came upon open country (chapada) on both sides, and went over small corrideiras, which we got to like, as we travelled along on them at a greater speed than in the still waters, with a minimum of exertion. The river seemed to be getting narrower all the time that day, and, of course, deeper. In many spots it went through a channel not more than 30 m. wide.
We heard—but not for long—the cackling of the jacu (Penelope cristata), a handsome gallinaceous bird. The jacu made most delicious eating. Then that day flocks of small green parrots flew over our heads on several occasions.
Ariranhas gave us once more a good deal of amusement and sport. It was seldom one found such cheeky and inquisitive animals. They would pop their heads out of the water quite close to the canoe and sniff and grind their teeth at us. They had beautiful little heads—something between a cat and a seal—with lovely, but wicked, black eyes of wonderful luminosity. They had a perfect craving for blood. The Brazilians have strange tales about them—not exactly fit for publication.
The sand beaches were not so frequent as we advanced on our journey. We noticed instead extensive beaches of gravel. Another tributary stream, 10 m. wide at its mouth, entered the Arinos from the east. There was heavy forest there with plenty of rubber-trees on the right bank, whereas the country was open on the left bank.
Farther down, the banks became low, so that the slightest rise in the river would inundate the country. The forest was particularly thick, and the rubber trees plentiful, along a stretch of 4,300 m. of river in a perfectly straight line.
The river was getting more and more beautiful at every turn. We emerged into a bay 300 m. in diameter. Great blocks of conglomerate were strewn about. A great spur projected to the centre of the bay. The richness in rubber of that region was amazing. Wonderful giant trees, heavily laden with dark green foliage, were reflected in deeper tones in the water of the river—there almost stagnant because held up by some obstacle lower down. Innumerable festoons of creepers hung down from those trees. The stream was there 80 m. wide, and beautiful that day in great stretches of 4,300 m., 1,400 m., 1,000 m., 3,000 m., 1,500 m., and 1,200 m.—in a perfectly straight line. The forest was occasionally interrupted on one side or the other by great expanses of chapada.
