Masisi is a high plateau region located in the ‘sous-region’ of Nord Kivu. This area is part of the Mitumba Mountain Range which forms the boundary between the Zaire Basin and the Great Rift Valley. The mountains rising out of Lake Kivu reach heights of 2, 000-2, 700 meters, and the region receives large amounts of rainfall. The Osso River, a tributary of the Congo River, has its source here. In the past the region has been described as the land of the Bahunde tribe, but after 1937, in accordance with Belgian immigration policies, peoples such as the Tutsi and Hutu have flowed in from Ruanda and settled here. In Zaire, immigrants from Ruanda are grouped together under the appellation “Banyarwanda”, which extends also to the Twa (pygmies). These people now slightly exceed the original Bahunde inhabitants in population, and they are culturally predominant. With regard to occupational patterns, the Tutsi are in general cattle-raisers, the Hutu cultivators, and the Twa hunters and gatherers, but in Zaire the Banyarwanda have adapted themselves as a predominantly agricultural people engaged in mixed farming. They arrange their dwellings in line villages (called “Urusisiro”) built along ridges of hills, and the slopes on both sides of the ridge are used as farm land. The principal crops are bananas, cassava, maize, sorghum (guinea corn), sweet potatoes, white potatoes, cocoyams, beans, squash, green vegetables, etc., and in many cases the surplus produce is exchanged for cash at the market place. Domestic animals and fowl such as cattle, goats, swine, domestic ducks and chickens are raised, but this is a spare time activity and the numbers are few. Even in the case of cattle, the most highly valued livestock, each household possesses an average of only about two or three animals, and each village (Urusisiro) usually has one Kraal (Rugo) where cattle are cared for co-operatively. In contrast, however, large-scale cattle raising developed by Europeans and wealthy local zaïrois entreprepreneurs (the former have in recent years been bought over by the government in the Zaireization process) is making Breast progress in the Masisi region. The pasture lands of the Banyarwanda have been limited, and there is little possibility of raising large unmbers of livestock. The economic pattern centering around the Rusisiro is a traditional one. but even in regard to more recent factors it seems to illustrate an aspect of the mixed farming system, which can be adapted to varying circumstances with little difficulty.