On the following day we made nineteen kilometres, the river twisting in every direction, but in its general course running a little west of north.  Once we stopped at a bee-tree, to get honey.  The tree was a towering giant, of the kind called milk-tree, because a thick milky juice runs freely from any cut.  Our camaradas eagerly drank the white fluid that flowed from the wounds made by their axes.  I tried it.  The taste was not unpleasant, but it left a sticky feeling in the mouth.  The helmsman of my boat, Luiz, a powerful negro, chopped into the tree, balancing himself with springy ease on a slight scaffolding.  The honey was in a hollow, and had been made by medium-sized stingless bees.  At the mouth of the hollow they had built a curious entrance of their own, in the shape of a spout of wax about a foot long.  At the opening the walls of the spout showed the wax formation, but elsewhere it had become in color and texture indistinguishable from the bark of the tree.  The honey was delicious, sweet and yet with a tart flavor.  The comb differed much from that of our honey-bees.  The honey-cells were very large, and the brood-cells, which were small, were in a single instead of a double row.  By this tree I came across an example of genuine concealing coloration.  A huge tree-toad, the size of a bullfrog, was seated upright—­not squatted flat—­on a big rotten limb.  It was absolutely motionless; the yellow brown of its back, and its dark sides, exactly harmonized in color with the light and dark patches on the log; the color was as concealing, here in its natural surroundings, as is the color of our common wood-frog among the dead leaves of our woods.  When I stirred it up it jumped to a small twig, catching hold with the disks of its finger-tips, and balancing itself with unexpected ease for so big a creature, and then hopped to the ground and again stood motionless.  Evidently it trusted for safety to escaping observation.  We saw some monkeys and fresh tapir sign, and Kermit shot a jacu for the pot.

At about three o’clock I was in the lead, when the current began to run more quickly.  We passed over one or two decided ripples, and then heard the roar of rapids ahead, while the stream began to race.  We drove the canoe into the bank, and then went down a tapir trail, which led alongside the river, to reconnoiter.  A quarter of a mile’s walk showed us that there were big rapids, down which the canoes could not go; and we returned to the landing.  All the canoes had gathered there, and Rondon, Lyra, and Kermit started down-stream to explore.  They returned in an hour, with the information that the rapids continued for a long distance, with falls and steep pitches of broken water, and that the portage would take several days.  We made camp just above the rapids.  Ants swarmed, and some of them bit savagely.  Our men, in clearing away the forest for our tents, left several very tall and slender accashy palms; the bole of this palm is as straight as an arrow and is crowned with delicate, gracefully curved fronds.  We had come along the course of the river almost exactly a hundred kilometres; it had twisted so that we were only about fifty-five kilometres north of our starting-point.  The rock was porphyritic.