These lectures were delivered at the London School of Economics in May of this year. They are primarily based on experiences gained during the Percy Sladen Trust Expedition to Melanesia in 1908 and provide a simplified account of the social conditions that will be detailed in the full report of the expedition's work.
Since the lectures were presented, a few minor additions and modifications have been made, some of which were suggested by Professor Westermarck and Dr. Malinowski during the subsequent discussions. I would also like to express my gratitude to Miss B. Freire-Marreco for permitting me to reference unpublished material collected during her recent work among the Pueblo Indians of North America.