This account of the Cahuilla, one of the largest surviving tribes in southern California, represents the work of Lucile Hooper as University of California research fellow in anthropology in 1918. There is a considerable body of published literature on the Cahuilla and other Indian tribes of southern California, but no intensive monograph upon any one tribe nor a satisfactory comprehensive treatment of the region. The literature being so scattered, its citation would have resulted in innumerable detailed cross-references in foot notes, which the ethnological specialist in this field would scarcely need, and which would not be of much aid to the novice. The list of the more important works given at the end of this paper will probably meet the requirements of most readers.