1905 Lumholtz was a founding member of the Explorers Club, an organization to promote exploration and scientific investigation in the field. He went on a brief expedition to India from 1914–1915, then to Borneo from 1915 to 1917, which was his last expedition. Borneo Lumholtz started an expedition in 1914 to explore the mostly unknown lands of Dutch Central Borneo, currently part of Indonesia. His primary focus was to interact with the indigenous peoples to learn about their culture and habits, although he also was interested in the flora and fauna of the area. He received numerous financial grants from geographical institutions (Norwegian Geographical Society, the Royal Geographical Society of London and the Koninklijk Nederlandsch Aardrijkskundig Genootschap), but his journey was complicated by the outbreak of the First World War which made it difficult to acquire a military escort. He originally had planned to explore New Guinea, but this was rendered impossible by the war. He encountered two new species of flying squirrels and one new species of colugo that were native to the area. He presented his findings in 1916 in Amsterdam in a film titled Borneo Gefilmd (translated: The filming of Borneo) which was about 40 minutes long. In this expedition Lumholtz encountered several different tribes of indigenous people. One of them was the Dayak people, which not only are masters of woodcutting but also show tremendous fortitude when in battle with crocodiles, according to Lumholtz. They also played an important part in Lumholtz's expedition, by making camps and snares for catching wildlife, and carrying supplies for him. (Dayaks has been considered a collective term for the native people of Borneo.) Another people Lumholtz encountered were the Punan. When Lumholtz visited the Punan, they had already discontinued the practice of head-hunting and where now a peaceful and harmless people, according to Lumholtz. He also stated that the Punan had probably copied this custom from the Dayaks. Lumholtz wrote on his experiences in Borneo in his book, Through Central Borneo; an account of two years' travel in the land of the head-hunters between the years 1913 and 1917, published in 1920. Later life In 1922 Lumholtz died of tuberculosis at Saranac Lake, New York, where he was seeking treatment at a sanatorium. He had published six books on his discoveries, as well as the autobiography My Life of Exploration (1921). Legacy and honors His greatest legacy was his books