Early explorers of the region emerged from the jungle skinny, unkempt and often unhinged. Many of them starved: In ''The Lost City of Z'' David Grann describes several expeditions undertaken in the 1920's by the legendary explorer Percy Fawcett who was as famous for vanishing without a trace as for his discoveries: ''Scrounging for food, Fawcett and his men could make out only buttressed tree trunks and cascades of vines. Chemical-laced fungi and billions of termites and ants had stripped bare much of the jungle floor. Fawcett had been taught to scavenge for dead animals, but there were none to be found: every corpse was instantly recycled back into the living. Trees drained even more nutrients from a soil already leached by rain and floods.''
They encountered sweat bees (drawn to sweat, of which there was surely an abundance, and called - horribly - ''eye lickers'' in Brazil), vampire bats that transmitted lethal protozoa, malarial mosquitos, maggots that infected open wounds, electric eels that sizzled the horses and dogs they had with them, fire ants, piranhas, poisonous vipers, poisonous ants, termites, caymans, trees with poisonous sap (the curare tree comes to mind) poisonous frogs (the poison dart frog) and leg-eating mud-holes. (I can vouch for the latter, having stepped in one near a lily pad lagoon. It took two people to pull me out. Fortunately the mud hadn't gotten above my boots. Yup, another reason to wear boots.) In ''The River of Doubt,'' about Teddy Roosevelt's Amazon expedition, author Candace Millard adds: ''The rain forest was not a garden of easy abundance, but precisely the opposite: Its quiet, shaded halls of leafy opulence were not a sanctuary, but rather the greatest natural battlefield anywhere on the planet, hosting an unremitting and remorseless fight for survival that occupied every single one of its in habitants, every minute of every day.'' Whew.