The biting flies and ants were to us a source of discomfort and at times of what could fairly be called torment.  But to the camaradas, most of whom went barefoot or only wore sandals—­and they never did or would wear shoes—­the effect was more serious.  They wrapped their legs and feet in pieces of canvas or hide; and the feet of three of them became so swollen that they were crippled and could not walk any distance.  The doctor, whose courage and cheerfulness never flagged, took excellent care of them.  Thanks to him, there had been among them hitherto but one or two slight cases of fever.  He administered to each man daily a half-gram—­nearly eight grains—­of quinine, and every third or fourth day a double dose.

The following morning Colonel Rondon, Lyra, Kermit, Cherrie, and nine of the camaradas started in single file down the bank, while the doctor and I went in the two double canoes, with six camaradas, three of them the invalids with swollen feet.  We halted continually, as we went about three times as fast as the walkers; and we traced the course of the river.  After forty minutes’ actual going in the boats we came to some rapids; the unloaded canoes ran them without difficulty, while the loads were portaged.  In an hour and a half we were again under way, but in ten minutes came to other rapids, where the river ran among islands, and there were several big curls.  The clumsy, heavily laden dugouts, lashed in couples, were unwieldy and hard to handle.  The rapids came just round a sharp bend, and we got caught in the upper part of the swift water and had to run the first set of rapids in consequence.  We in the leading pair of dugouts were within an ace of coming to grief on some big boulders against which we were swept by a cross current at the turn.  All of us paddling hard—­ scraping and bumping—­we got through by the skin of our teeth, and managed to make the bank and moor our dugouts.  It was a narrow escape from grave disaster.  The second pair of lashed dugouts profited by our experience, and made the run—­with risk, but with less risk—­and moored beside us.  Then all the loads were taken out, and the empty canoes were run down through the least dangerous channels among the islands.

This was a long portage, and we camped at the foot of the rapids, having made nearly seven kilometres.  Here a little river, a rapid stream of volume equal to the Duvida at the point where we first embarked, joined from the west.  Colonel Rondon and Kermit came to it first, and the former named it Rio Kermit.  There was in it a waterfall about six or eight feet high, just above the junction.  Here we found plenty of fish.  Lyra caught two pacu, good-sized, deep-bodied fish.  They were delicious eating.  Antonio the Parecis said that these fish never came up heavy rapids in which there were falls they had to jump.  We could only hope that he was correct, as in that case the rapids we would encounter in the future would rarely be so serious as to necessitate our dragging the heavy dugouts overland.  Passing the rapids we had hitherto encountered had meant severe labor and some danger.  But the event showed that he was mistaken.  The worst rapids were ahead of us.