There were a few piums and gnats, and a few mosquitoes after dark, but not enough to make us uncomfortable.  The small stingless bees, of slightly aromatic odor, swarmed while daylight lasted and crawled over our faces and hands; they were such tame, harmless little things that when they tickled too much I always tried to brush them away without hurting them.  But they became a great nuisance after a while.  It had been raining at intervals, and the weather was overcast; but after the sun went down the sky cleared.  The stars were brilliant overhead, and the new moon hung in the west.  It was a pleasant night, the air almost cool, and we slept soundly.

Next morning the two surveying canoes left immediately after breakfast.  An hour later the two pairs of lashed canoes pushed off.  I kept our canoe to let Cherrie collect, for in the early hours we could hear a number of birds in the woods near by.  The most interesting birds he shot were a cotinga, brilliant turquoise-blue with a magenta-purple throat, and a big woodpecker, black above and cinnamon below with an entirely red head and neck.  It was almost noon before we started.  We saw a few more birds; there were fresh tapir and paca tracks at one point where we landed; once we heard howler monkeys from the depth of the forest, and once we saw a big otter in midstream.  As we drifted and paddled down the swirling brown current, through the vivid rain-drenched green of the tropic forest, the trees leaned over the river from both banks.  When those that had fallen in the river at some narrow point were very tall, or where it happened that two fell opposite each other, they formed barriers which the men in the leading canoes cleared with their axes.  There were many palms, both the burity with its stiff fronds like enormous fans, and a handsome species of bacaba, with very long, gracefully curving fronds.  In places the palms stood close together, towering and slender, their stems a stately colonnade, their fronds an arched fretwork against the sky.  Butterflies of many hues fluttered over the river.  The day was overcast, with showers of rain.  When the sun broke through rifts in the clouds, his shafts turned the forest to gold.

In mid-afternoon we came to the mouth of a big and swift affluent entering from the right.  It was undoubtedly the Bandeira, which we had crossed well toward its head, some ten days before, on our road to Bonofacio.  The Nhambiquaras had then told Colonel Rondon that it flowed into the Duvida.  After its junction, with the added volume of water, the river widened without losing its depth.  It was so high that it had overflowed and stood among the trees on the lower levels.  Only the higher stretches were dry.  On the sheer banks where we landed we had to push the canoes for yards or rods through the branches of the submerged trees, hacking and hewing.  There were occasional bays and ox-bows from which the current had shifted.  In these the coarse marsh grass grew tall.