On the 8th we had tolerably quiet water, with only two small rapids, the “Taiéna” (Child), and “Paroquet” caxoeiras. On the 9th, in the morning, we reached the “Pacu” fall, and then had a quiet stream, though full of rocks, till the afternoon, when we passed the “Macucú” (a tree), “Ananás” (Pine-apple), and “Uacú” (a fruit) caxoeiras; all very bad and difficult ones. We had left Carurú with very little farinha, as none was to be had there, and we had seen no inhabited sitios where any could be purchased; so the Indians were now on short allowance of “beijú,” which they had brought with them. Of a passing Indian I bought a basket of Ocokí, and some fish. The Ocokí is a large pear-shaped fruit, with a hard thick outer skin of almost a woody texture, then a small quantity of very sweet pulpy matter, and within a large black oval stone. The pulp is very luscious, but is so acrid as to make the mouth and throat sore, if more than two or three are eaten. When however the juice is boiled, it loses this property; and when made into mingau with tapioca, is exceedingly palatable, and generally highly esteemed in the Upper Rio Negro, where it is abundant. It takes at least a peck of fruit, to give one small panella of mingau. On the next day, the 10th, in the afternoon, the Indians all suddenly sprang like otters into the water, swam to the shore, and disappeared in the forest. “Ocokí,” was the answer to my inquiries as to the cause of their sudden disappearance; and I soon found they had discovered an ocokí-tree, and were loading themselves with the fruit to satisfy the cravings of hunger, for an Indian’s throat and mouth seem invulnerable to all those scarifying substances which act upon civilized man. The tree is one of the loftiest in the forest, but the fruit falls as soon as ripe, and its hard woody coating preserves it from injury. Baskets, shirts, trowsers, etc., were soon filled with the fruit and emptied into the canoe; and I made each of the Indians bring a small basketful for me; so that we had “mingau de ocokí” for three succeeding mornings. The rocks from Carurú often present a scoriaceous appearance, as if the granite had been remelted. Sometimes they are a mass of burnt fragments, sometimes a honeycombed rock with a shining surface. In some places there are enclosed fragments of a finer-grained rock, apparently sandstone, and numerous veins and dykes, which often cross each other in three or four sets. The rocks are, in many places, so broken and cleft vertically, as to appear stratified and thrown up on end. The rounded form and concentric arrangement, observed in the Rio Negro, is here also constantly met with. The interstices of the rounded and angular masses of rock are often filled with a curious volcanic substance, which outwardly resembles pitch, but consists of scoriæ, sand, clays, etc., variously cemented together.