Theodor Koch-Grünberg (1872–1924) was a noted German ethnologist and explorer whose work on the indigenous peoples of Brazil and Venezuela is still consulted by anthropologists, ethnologists and linguists. His most important book is this five-volume account of his expedition of 1911–1913 from the sandstone mountains bordering Brazil, Venezuela and Guyana through uncharted territory westwards to the Orinoco. Volume 4 contains the linguistic data collected on the expedition, including a grammatical description of Taulipáng (Taurepan) with word lists and texts. Eighteen further languages and dialects, seven of them previously unknown, are also represented, mostly by word lists with phonetic transcriptions using the 'Anthropos' system. Three languages were already facing extinction, four were language isolates, and several had previously been described only briefly. This truly ground-breaking work provided a linguistic overview of the greater part of a large geographical area, and a foundation for much future research.