Anthropologists are hard put to it when asked to recommend a book that shall give the layman a brief summary of what is now known regarding their science as a whole or any one of its branches. They are usually obliged to confess that such an up-to-date synthesis as is likely to satisfy the questioner does not exist. In no department of anthropology has the want of a modern summary made itself more painfully felt than in that of social organization. Sociologists, historians, and students of comparative jurisprudence all require the data the anthropologist might supply, but for lack of a general guide they have been content to find inspiration in Morgan's Ancient Society, a book written when scientific ethnography was in its infancy. Since 1877 anthropologists have not merely amassed a wealth of concrete material but have developed new methods and points of view that render Morgan hopelessly antiquated. His work remains an important pioneer effort by a man of estimable intelligence and exemplary industry, but to get one's knowledge of primitive society therefrom nowadays is like getting one's biology from some pre-Darwinian naturalist. It is emphatically a book for the historian of anthropology and not for the general reader.