The text offers a detailed ethnographic portrait of interior Borneo riverine communities, focusing on daily home life, social customs, festivals, and material culture among Kayan and Kenyah peoples. It records naming ceremonies, youth training for warfare, the organization and conduct of head-hunting expeditions and peace-making rituals, and practices of tattooing, ornamentation, and tabu observances. Chapters describe food production, fishing and camphor collection, domestic architecture, and relations with traders, interweaving first-person observations with illustrations and plates to show craftsmen, musical instruments, and ritual objects.