"The Social Life of the Blackfoot Indians" by Clark Wissler is an anthropological study written in the early 20th century. The book explores the social and cultural systems of the Blackfoot Indians, detailing various aspects such as tribal divisions, marriage customs, and property rights. It aims to provide an in-depth understanding of the social structures and practices of this Indigenous group, based on data collected through fieldwork and collaboration with knowledgeable members of the community. The opening of the work presents an introduction to the author's research and sets up the framework for the ensuing chapters. Wissler acknowledges the contributions of various individuals in collecting the data, particularly highlighting his collaboration with Mr. D. C. Duvall. He touches on the tribal divisions within the Blackfoot, such as the Piegan, Blood, and Northern Blackfoot, and suggests that the band system they utilize is flexible and evolves with sociological and economic conditions. This portion of the text serves to establish the context and importance of understanding the social life of the Blackfoot, as well as introduces the various topics to be examined in subsequent sections. (This is an automatically generated summary.)