A little above the Davipe mission the Río Negro receives a branch of the Casiquiare whose existence is a remarkable phenomenon in the history of river branching. This branch emerges from the Casiquiare, north of Vasiva, under the name Itinivi; and after crossing a flat, virtually uninhabited country some 25 leagues long, pours into the Río Negro under the name of Río Conorichite. It seemed to me, near its mouth, to be 120 toises wide, and added large quantities of white waters to the black waters. Even though the Conorichite current is very fast, you shorten the journey from Davipe to Esmeralda by three days using this canal. It is not surprising to find a double communication between the Casiquiare and the Río Negro when you recall that so many American rivers form deltas when they meet other rivers. In this way the Branco and the Jupura pour into the Río Negro and Amazon through many branches. At the confluence with the Jupura there is another more extraordinary phenomenon. Before joining the Amazon this river, which is its main recipient, sends three branches called Uaranapu, Manhama and Avateprana to the Jupura, which is none other than its tributary. The Amazon thus sends its waters into the Jupura before receiving the waters of the latter back.