At this camp the carregadores ants completely devoured the doctor's undershirt, and ate holes in his mosquito-net; and they also ate the strap of Lyra's gun-case. The little stingless bees, of many kinds, swarmed in such multitudes, and were so persevering, that we had to wear our head-nets when we wrote or skinned specimens.

The following day was almost without rain. It was delightful to drift and paddle slowly down the beautiful tropical river. Until mid- afternoon the current was not very fast, and the broad, deep, placid stream bent and curved in every direction, although the general course was northwest. The country was flat, and more of the land was under than above water. Continually we found ourselves travelling between stretches of marshy forest where for miles the water stood or ran among the trees. Once we passed a hillock. We saw brilliantly colored parakeets and trogons. At last the slow current quickened. Faster it went, and faster, until it began to run like a mill-race, and we heard the roar of rapids ahead. We pulled to the right bank, moored the canoes, and while most of the men pitched camp two or three of them accompanied us to examine the rapids. We had made twenty kilometres.

We soon found that the rapids were a serious obstacle. There were many curls, and one or two regular falls, perhaps six feet high. It would have been impossible to run them, and they stretched for nearly a mile. The carry, however, which led through woods and over rocks in a nearly straight line, was somewhat shorter. It was not an easy portage over which to carry heavy loads and drag heavy dugout canoes. At the point where the descent was steepest there were great naked flats of friable sandstone and conglomerate. Over parts of these, where there was a surface of fine sand, there was a growth of coarse grass. Other parts were bare and had been worn by the weather into fantastic shapes—one projection looked like an old-fashioned beaver hat upside down. In this place, where the naked flats of rock showed the projection of the ledge through which the river had cut its course, the torrent rushed down a deep, sheer-sided, and extremely narrow channel. At one point it was less than two yards across, and for quite a distance not more than five or six yards. Yet only a mile or two above the rapids the deep, placid river was at least a hundred yards wide. It seemed extraordinary, almost impossible, that so broad a river could in so short a space of time contract its dimensions to the width of the strangled channel through which it now poured its entire volume.

This has for long been a station where the Nhambiquaras at intervals built their ephemeral villages and tilled the soil with the rude and destructive cultivation of savages. There were several abandoned old fields, where the dense growth of rank fern hid the tangle of burnt and fallen logs. Nor had the Nhambiquaras been long absent. In one trail we found what gypsies would have called a "pateran," a couple of branches arranged crosswise, eight leaves to a branch; it had some special significance, belonging to that class of signals, each with some peculiar and often complicated meaning, which are commonly used by many wild peoples. The Indians had thrown a simple bridge, consisting of four long poles, without a hand-rail, across one of the narrowest parts of the rock gorge through which the river foamed in its rapid descent. This sub-tribe of Indians was called the Navaite; we named the rapids after them, Navaite Rapids. By observation Lyra found them to be (in close approximation to) latitude 11 degrees 44 minutes south and longitude 60 degrees 18 minutes west from Greenwich.

We spent March 3 and 4 and the morning of the 5th in portaging around the rapids. The first night we camped in the forest beside the spot where we had halted. Next morning we moved the baggage to the foot of the rapids, where we intended to launch the canoes, and pitched our tents on the open sandstone flat. It rained heavily. The little bees were in such swarms as to be a nuisance. Many small stinging bees were with them, which stung badly. We were bitten by huge horse-flies, the size of bumblebees. More serious annoyance was caused by the pium and boroshuda flies during the hours of daylight, and by the polvora, the sand-flies, after dark. There were a few mosquitoes. The boroshudas were the worst pests; they brought the blood at once, and left marks that lasted for weeks. I did my writing in head-net and gauntlets. Fortunately we had with us several bottles of "fly dope"—so named on the label—put up, with the rest of our medicine, by Doctor Alexander Lambert; he had tested it in the north woods and found it excellent. I had never before been forced to use such an ointment, and had been reluctant to take it with me; but now I was glad enough to have it, and we all of us found it exceedingly useful. I would never again go into mosquito or sand-fly country without it. The effect of an application wears off after half an hour or so, and under many conditions, as when one is perspiring freely, it is of no use; but there are times when minute mosquitoes and gnats get through head-nets and under mosquito-bars, and when the ointments occasionally renewed may permit one to get sleep or rest which would otherwise be impossible of attainment. The termites got into our tent on the sand- flat, ate holes in Cherrie's mosquito-net and poncho, and were starting to work at our duffel-bags, when we discovered them.

Packing the loads across was simple. Dragging the heavy dugouts was labor. The biggest of the two water-logged ones was the heaviest. Lyra and Kermit did the job. All the men were employed at it except the cook, and one man who was down with fever. A road was chopped through the forest and a couple of hundred stout six-foot poles, or small logs, were cut as rollers and placed about two yards apart. With block and tackle the seven dugouts were hoisted out of the river up the steep banks, and up the rise of ground until the level was reached. Then the men harnessed themselves two by two on the drag-rope, while one of their number pried behind with a lever, and the canoe, bumping and sliding, was twitched through the woods. Over the sandstone flats there were some ugly ledges, but on the whole the course was down-hill and relatively easy. Looking at the way the work was done, at the good-will, the endurance, and the bull-like strength of the camaradas, and at the intelligence and the unwearied efforts of their commanders, one could but wonder at the ignorance of those who do not realize the energy and the power that are so often possessed by, and that may be so readily developed in, the men of the tropics. Another subject of perpetual wonder is the attitude of certain men who stay at home, and still more the attitude of certain men who travel under easy conditions, and who belittle the achievements of the real explorers of, the real adventures in, the great wilderness. The impostors and romancers among explorers or would-be explorers and wilderness wanderers have been unusually prominent in connection with South America (although the conspicuous ones are not South Americans, by the way); and these are fit subjects for condemnation and derision. But the work of the genuine explorer and wilderness wanderer is fraught with fatigue, hardship, and danger. Many of the men of little knowledge talk glibly of portaging as if it were simple and easy. A portage over rough and unknown ground is always a work of difficulty and of some risk to the canoe; and in the untrodden, or even in the unfrequented, wilderness risk to the canoe is a serious matter. This particular portage at Navaite Rapids was far from being unusually difficult; yet it not only cost two and a half days of severe and incessant labor, but it cost something in damage to the canoes. One in particular, the one in which I had been journeying, was split in a manner which caused us serious uneasiness as to how long, even after being patched, it would last. Where the canoes were launched, the bank was sheer, and one of the water-logged canoes filled and went to the bottom; and there was more work in raising it.

We were still wholly unable to tell where we were going or what lay ahead of us. Round the camp-fire, after supper, we held endless discussions and hazarded all kinds of guesses on both subjects. The river might bend sharply to the west and enter the Gy-Parana high up or low down, or go north to the Madeira, or bend eastward and enter the Tapajos, or fall into the Canuma and finally through one of its mouths enter the Amazon direct. Lyra inclined to the first, and Colonel Rondon to the second, of these propositions. We did not know whether we had one hundred or eight hundred kilometres to go, whether the stream would be fairly smooth or whether we would encounter waterfalls, or rapids, or even some big marsh or lake. We could not tell whether or not we would meet hostile Indians, although no one of us ever went ten yards from camp without his rifle. We had no idea how much time the trip would take. We had entered a land of unknown possibilities.

We started down-stream again early in the afternoon of March 5. Our hands and faces were swollen from the bites and stings of the insect pests at the sand-flat camp, and it was a pleasure once more to be in the middle of the river, where they did not come, in any numbers, while we were in motion. The current was swift, but the river was so deep that there were no serious obstructions. Twice we went down over slight riffles, which in the dry season were doubtless rapids; and once we struck a spot where many whirlpools marked the presence underneath of boulders which would have been above water had not the river been so swollen by the rains. The distance we covered in a day going down-stream would have taken us a week if we had been going up. The course wound hither and thither, sometimes in sigmoid curves; but the general direction was east of north. As usual, it was very beautiful; and we never could tell what might appear around any curve. In the forest that rose on either hand were tall rubber-trees. The surveying canoes, as usual, went first, while I shepherded the two pairs of lashed cargo canoes. I kept them always between me and the surveying canoes—ahead of me until I passed the surveying canoes, then behind me until, after an hour or so, I had chosen a place to camp. There was so much overflowed ground that it took us some little time this afternoon before we found a flat place high enough to be dry. Just before reaching camp Cherrie shot a jacu, a handsome bird somewhat akin to, but much smaller than, a turkey; after Cherrie had taken its skin, its body made an excellent canja. We saw parties of monkeys; and the false bellbirds uttered their ringing whistles in the dense timber around our tents. The giant ants, an inch and a quarter long, were rather too plentiful around this camp; one stung Kermit; it was almost like the sting of a small scorpion, and pained severely for a couple of hours. This half-day we made twelve kilometres.

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.