This work, posthumously published, represents the culmination of over thirty years of work, and it is the end result of a dozen studies of California’s aborigines published since 1940. The first chapters fill in three regions which were missing from the earlier inquiry into the development of the Indian population since contact with the whites after 1769: the Sacramento Valley, the “Mission Strip” from San Diego to San Francisco, and California east of the Sierra Nevada. The next chapters bring the demographic picture up to 1970, studying age distribution and vital statistics which reflect responses to environment and disease among many factors. The fifth and sixth essays break entirely new ground. They present a comparative study of Indian and White populations and the impact of interracial fusion on the magnitude of both populations. The graphs and tables which are based upon highly sophisticated methods are explained in straightforward language. Cook estimates the California Indian population in 1769 to have numbered 310,000, give or take ten percent.

For Latin Americanists, special interest lies in the study of the impact of the Spanish Missions. The scrupulous assessment of the sources, cross-checked wherever possible, is a model exercise. The author not only analyzes the texts as such, but he gives invaluable hints as to their editions and prior use, and the impact of such past scholarship upon the traditional estimates of populations. This book is a fitting capstone to a unique and impressive life-long enterprise which has stimulated many scholars here and abroad.