flat part of the rock, of four multiple circles with a dot in the middle (O), very accurately made and about a foot and a half in diameter; and below them, on the side of the rock, four multiple m’s or inverted w’s (M).  What these curious symbols represented, or who made them, we could not, of course, form the slightest idea.  It may be that in a very remote past some Indian tribes of comparatively advanced culture had penetrated to this lovely river, just as we had now come to it.  Before white men came to South America there had already existed therein various semi-civilizations, some rude, others fairly advanced, which rose, flourished, and persisted through immemorial ages, and then vanished.  The vicissitudes in the history of humanity during its stay on this southern continent have been as strange, varied, and inexplicable as paleontology shows to have been the case, on the same continent, in the history of the higher forms of animal life during the age of mammals.  Colonel Rondon stated that such figures as these are not found anywhere else in Matto Grosso where he has been, and therefore it was all the more strange to find them in this one place on the unknown river, never before visited by white men, which we were descending.

Next morning we went about three kilometers before coming to some steep hills, beautiful to look upon, clad as they were in dense, tall, tropical forest, but ominous of new rapids.  Sure enough, at their foot we had to haul up and prepare for a long portage.  The canoes we ran down empty.  Even so, we were within an ace of losing two, the lashed couple in which I ordinarily journeyed.  In a sharp bend of the rapids, between two big curls, they were swept among the boulders and under the matted branches which stretched out from the bank.  They filled, and the racing current pinned them where they were, one partly on the other.  All of us had to help get them clear.  Their fastenings were chopped asunder with axes.  Kermit and half a dozen of the men, stripped to the skin, made their way to a small rock island in the little falls just above the canoes, and let down a rope which we tied to the outermost canoe.  The rest of us, up to our armpits and barely able to keep our footing as we slipped and stumbled among the boulders in the swift current, lifted and shoved while Kermit and his men pulled the rope and fastened the slack to a half-submerged tree.  Each canoe in succession was hauled up the little rock island, baled, and then taken down in safety by two paddlers.  It was nearly four o’clock before we were again ready to start, having been delayed by a rain-storm so heavy that we could not see across the river.  Ten minutes’ run took us to the head of another series of rapids; the exploring party returned with the news that we had an all day’s job ahead of us; and we made camp in the rain, which did not matter much, as we were already drenched through.  It was impossible, with the wet wood, to make a fire sufficiently hot to dry all our soggy things, for the rain was still falling.  A tapir was seen from our boat, but, as at the moment we were being whisked round in a complete circle by a whirlpool, I did not myself see it in time to shoot.