The peyote cult by Weston La Barre is an anthropological monograph written in the early 20th century. It examines the peyote religion among Indigenous peoples of Mexico and the United States, combining ethnography, history, botany, pharmacology, and psychology. The study traces peyote’s diffusion from Mexico into the Plains, compares rituals and doctrines across tribes, and analyzes the rise of the Native American Church alongside legal and social controversies. The opening of the monograph lays out the author’s fieldwork among numerous tribes, extensive acknowledgments to Indigenous collaborators and scholars, and a promise—reinforced in a reprint note—to synthesize a rapidly growing literature. The introduction defines peyote, distinguishes it from other narcotics, summarizes its physiological effects and non-ritual uses, and sketches its spread from Mexican ceremonial contexts to Plains all-night tipi meetings, including variants linked to leaders such as John Wilson and Jonathan Koshiway and the formation of the Native American Church. A survey of prior scholarship positions the work as a needed comparative synthesis. The subsequent botanical and physiological sections clarify taxonomy and plant description, address myths (the “hiding” plant, male/female forms), personifications (e.g., “Peyote Woman”), naming and misnomers (“mescal”), and the true Nahuatl etymology, then relate drug effects (exhilaration, depression, visions) to ritual features like night-long singing, water rites, sweets, salt taboos, and vision-inspired song-making—while questioning claims about anti-alcohol effects. The ethnology section begins with non-ritual functions—divination, war protection, witchcraft struggles, and healing—then turns to formal rites, summarizing the Huichol pilgrimage-and-feast complex and the Tarahumara gathering-and-dance cycle. It closes this opening portion by moving toward a comparative account of northern Mexican ceremonies, segueing into a description of a Tamaulipecan night feast. (This is an automatically generated summary.)