Led by Matthew Stirling, ethnologist at the U.S. National Museum (Smithsonian), more then 400 expedition members travelled through the Mamberamo area searching for Papuans. This group consisted of 75 Dutch soldiers, 130 Dayaks, and 210 Malayan prisoners (chain gang). The expedition uses a water plane. The commentary speaks with scorn of the customs of the Papuans, or Pygmies as they are called in the film. The 1926 film production was a collaboration between the American Smithsonian Institution, the Dutch colonial authorities and the Royal Dutch Geographical Society (K.N.A.G.)