text: Perhaps more important than the introduction of material objects was the change in the economic and political structure of many African societies. In East Africa, Arab traders were primarily interested in securing slaves and ivory and, to a lesser degree, gold. Although slavery had not been unknown in pre-Arab days, largescale exploitation of slaves gave it a new aspect. More than ever before, human beings became a commodity which could be bartered for other commodities. Similarly ivory and gold, which in aboriginal days had had little if any value, suddenly, because of the demand, became prized possessions. Political leaders of African communities were quick to recognize the importance of these changes in value and attempted not infrequently to capitalize on them. Where, according to African tradition, chiefs had at least a nominal title to the country under their jurisdiction, they often declared monopolies over such articles as were in demand with the Arabs. Thus in many sections of the continent, elephants became royal game, making it obligatory for anyone killing an animal to deliver the valuable tusks to the chief, who retained for himself the exclusive right to deal with the traders. The Arabs, in turn, liked and probably favored this development, which greatly simplified their trade, since readily available storehouses were awaiting them.