The analogy of the European city from 1500 to 1800 applies to the case of the missions of central Baja California. Unhealthy conditions in the cities contributed to high mortality rates, rates higher than birth rates. Immigration from the rural hinterland, however, maintained and continued to expand urban populations. Overcrowding, poor diet and sanitation, and epidemics of smallpox and measles all contributed to high mortality in the cities (Flinn 1981: 22-23).
