These sand banks are considered to be the richest turtle grounds in the basin of the Upper Amazon.

On the evening of the 29th of July they were securely moored off the island of Catua, so as to pass the night, which promised to be dark.

On this island, as soon as the sun rose above the horizon, there appeared a party of Muras Indians, the remains of that ancient and powerful tribe, which formerly occupied more than a hundred leagues of the river bank between the Teffe and the Madeira.

These Indians went and came, watching the raft, which remained stationary. There were about a hundred of them armed with blow-tubes formed of a reed peculiar to these parts, and which is strengthened outside by the stem of a dwarf palm from which the pith has been extracted.

Joam Garral quitted for an instand the work which took up all his time, to warn his people to keep a good guard and not to provoke these Indians.

In truth the sides were not well matched. The Muras are remarkably clever at sending through their blow-tubes arrows which cause incurable wounds, even at a range of three hundred paces.

These arrows, made of the leaf of the _"coucourite"_ palm, are feathered with cotton, and nine or ten inches long, with a point like a needle, and poisoned with _"curare."_

Curare, or _"wourah,"_ the liquor "which kills in a whisper," as the Indians say, is prepared from the sap of one of the euphorbiaceæ and the juice of a bulbous strychnos, not to mention the paste of venomous ants and poisonous serpent fangs which they mix with it.

"It is indeed a terrible poison," said Manoel. "It attacks at once those nerves by which the movements are subordinated to the will. But the heart is not touched, and it does not cease to beat until the extinction of the vital functions, and besides no antidote is known to the poison, which commences by numbness of the limbs."

Very fortunately, these Muras made no hostile demonstrations, although they entertain a profound hatred toward the whites. They have, in truth, no longer the courage of their ancestors.

At nightfall a five-holed flute was heard behind the trees in the island, playing several airs in a minor key. Another flute answered. This interchange of musical phrases lasted for two or three minutes, and the Muras disappeared.

Fragoso, in an exuberant moment, had tried to reply by a song in his own fashion, but Lina had clapped her hand on his mouth, and prevented his showing off his insignificant singing talents, which he was so willingly lavish of.

On the 2d of August, at three o'clock in the afternoon, the raft arrived twenty leagues away from there at Lake Apoara, which is fed by the black waters of the river of the same name, and two days afterward, about five o'clock, it stopped at the entrance into Lake Coary.

This lake is one of the largest which communicates with the Amazon, and it serves as a reservoir for different rivers. Five or six affluents run into it, and there are stored and mixed up, and emerge by a narrow channel into the main stream.

After catching a glimpse of the hamlet of Tahua-Miri, mounted on its piles as on stilts, as a protection against inundation from the floods, which often sweep up over these low sand banks, the raft was moored for the night.

The stoppage was made in sight of the village of Coary, a dozen houses, considerably dilapidated, built I the midst of a thick mass of orange and calabash trees.

Nothing can be more changeable than the aspect of this village, for according to the rise or fall of the water the lake stretches away on all sides of it, or is reduced to a narrow canal, scarcely deep enough to communicate with the Amazon.

On the following morning, that of the 5th of August, they started at dawn, passing the canal of Yucura, belonging to the tangled system of lakes and furos of the Rio Zapura, and on the morning of the 6th of August they reached the entrance to Lake Miana.

No fresh incident occurred in the life on board, which proceeded with almost methodical regularity.