It was already dark when we crossed the Orinoco bed for the last time. We meant to spend the night near the small San Rafael fort and begin the journey across the Venezuelan steppes at dawn. Nearly six weeks had passed since our arrival at Angostura, we dearly wanted to reach the Cumanà or Nueva Barcelona coasts to find a boat to take us to Cuba and then on to Mexico. After several months on mosquito-infested rivers in small canoes, a long sea journey excited our imaginations.

Those who have not traveled the great rivers of tropical America, like the Orinoco or the Magdalena, cannot imagine how all day long, ceaselessly, you are tormented by mosquitoes that float in the air, and how this crowd of little animals can make huge stretches of land uninhabitable. However used to the pain you may become, without complaining; however much you try to observe the object you are studying, the mosquitoes, jejenes and zancudos will tear you away as they cover your head and hands, pricking you with their needle-like suckers through your clothes, and climbing into your nose and mouth, making you cough and sneeze whenever you try to talk. In the Orinoco missions the plaga de las moscas, or plague of mosquitoes, is an inexhaustible subject of conversation. When two people meet in the morning the first questions they ask each other are, 'Que le han parecido los zancudos de anoche? and 'Como estamos hoy de mosquitos? ('How were the zancudos last night? and 'How are we for mosquitoes today?').

We did not leave the Pericantral farm until dark. We spent a very uncomfortable night in the narrow, overloaded pirogue. At three in the morning we found ourselves at the mouth of the Manzanares river. As the sun rose we saw the zamuro vultures (Vultur aura) perched in flocks of forty and fifty in the coconut palms. To sleep, these birds line up together on branches like fowl, and are so lazy that they go to sleep ages before sunset and do not wake up until the sun is up. It seems as if the trees with pinnate leaves share this laziness with the birds. The mimosas and tamarinds close their leaves when the sky is clear some twenty-five to thirty-five minutes before sunset, and in the morning do not open them again until the sun is high up.

The sea-crossing from Santa Cruz to Cumana, the most eastern part of the New Continent, was indescribably beautiful. We cut the Tropic of Cancer on the 27th and, despite the Pizarro not being a fast sailer, took only twenty days to cover the 900 leagues that separate the African coast from the New World. Some land birds, blown out to sea by the strong wind, followed us for a few days.

April 27th. The night was beautiful; black clouds crossed the sky with surprising speed. Guapasoso's latitude was 3.53'55". The black waters served as my horizon. I was all the more delighted to make this observation as in the white-water rivers from the Apure to the Orinoco we had been cruelly bitten by mosquitoes, as Bonpland recorded the hours with the chronometer, and I myself adjusted the horizon. At two we left the Guapasoso conucos, going south and upstream as the river, at least that part of it free of trees, began to narrow. At sunrise it started to rain. In these forests we no longer heard the cries of the howler monkeys. Dolphins, or toninas, played by the side of our boat. At about midday we passed the mouth of the Ipurichapano river, and a little later the granite rock called Piedra del Tigre. We later regretted not resting near this rock as we had some problems trying to find a spot of dry land large enough upon which to light a fire and set up our hammocks and instruments.

After two days near the Atures cataract we were happy to load the canoe again and leave a place where the temperature was usually 29°C by day and 26°C at night. All day we were horribly tormented by mosquitoes and jejenes, tiny venomous flies (or simuliums), and all night by zancudos, another kind of mosquito feared even by the Indians. Our hands began to swell, and this swelling increased until we reached the banks of the Temi. The means found to escape these insects are often quite original. The kind missionary Father Zea, all his life tormented by mosquitoes, had built a small room near his church, up on a scaffolding of palm trunks, where you could breathe more freely. At night we climbed up a ladder to dry our plants and write our diary. The missionary had correctly observed that the insects preferred the lower levels, that is, from the ground up to some 15 feet. At Maypures the Indians leave their villages at night and sleep near the cataracts because the mosquitoes seem to avoid air loaded with vapors.