First British edition. With illustrations from photographs by Kermit Roosevelt and other members of the expedition. The American president's account of the Roosevelt-Rondon Scientific Expedition (Expedição Científica Roosevelt-Rondon) in the Brazilian hinterland. The expedition was initially intended primarily to collect mammals and birds for the American Museum of Natural History, but subsequently the scope of the expedition was enlarged to try to establish the course of the Rio da Dúvida (River of Doubt). Roosevelt's account includes descriptions of the fauna and flora, the terrain, tribes encountered, big-game hunting and the hardships of the expedition. Appendices on 'The work of the field zoologist and field geographer in South America' and 'The outfit for travelling in the South American wilderness'.