Bibliographical footnotes. An introduction, by R. Sennett.--The nature of the city, by M. Weber.--The metropolis and mental life, by G. Simmel.--The soul of the city, by O. Spengler.--The city; suggestions for the investigation of human behavior in the urban environment. Human migration and the marginal man. By R. Park.--Urbanism as a way of life. Rural-urban differences. Human ecology. By L. Wirth.--The folk society, by R. Redfield.--The cultural role of cities, by R. Redfield and M. Singer.