We landed in the middle of the Strait of Baraguan to measure the river's breadth. In this excessively hot place we looked in vain for plants in the clefts of rocks. The stones were covered with thousands of iguanas and geckos with spreading, membranous fingers. The thermometer placed against the rock rose to 50.2°C. The ground appeared to undulate in the mirages, without a breath of wind in the air. How vivid is the calm of nature at midday in these burning zones. The wild animals retire to the thickets; birds hide under leaves. Yet in this silence, if you listen carefully, you hear slight sounds, a dull vibration, a hum of insects. Nothing makes you sense the extent and power of organic life more keenly than this.