The region with which this study is concerned comprises the political units of Uganda, Kenya, Zanzibar, Tanganyika Territory, and the Belgian mandate of Ruanda and Urundi. (See Map I.) Its total area is some 727,000 square miles, i.e. more than eight times as large as that of Great Britain, though of this total area about 40,000 square miles consists of water surface. In 1931 the native African population totalled about 14,600,000, whilst the figure for the European population stood at 28,223. The European element is thus outnumbered in the proportion of more than 500 to 1, and even the total non-native population, including Europeans, Indians, Goans, and Arabs, is outnumbered in the ratio of 80 to 1. The native population constitutes a vastly preponderant element in the whole, and it is on the salient features of its distribution that the attention of this paper is wholly focused.