In Africa to-day the need for adequate investigation of nutritional problems is evident. As European civilization advances, the task of maintaining or providing for large sections of the native population diets which shall be adequate in quality as well as in quantity becomes more and more definite. In the practical sphere the problem is of a different complexion according to whether the community considered is an artificially induced concentration of people, as in schools, hospitals, prisons, and labour compounds, or is a comparatively spontaneous and free-moving aggregation in its own territory. A tribe which has been shifted back into a native reserve is in a kind of intermediate category. The index is, of course, the respective amount of initiative and control exercised by the European authority and by the native. What follows is a discussion of the dietetic situation in tribal conditions only. The maintenance of a balanced diet in a hospital or a labour compound is a comparatively simple matter if due scientific care is exercised; it is much more difficult to regulate the food-situation of a free-living native tribe. The two sets of problems are, however, not entirely unconnected, since with an increasing knowledge of the constitution of native foodstuffs, and experiment by the trial and error method, it has been found that quite a number of these are suitable for incorporation into a standard diet and can replace European foodstuffs. On the other hand, the advent of a money economy into the life of many tribes has made possible the purchase of imported foodstuffs to correct a deficiency in their diet if they so desire—though too often it has the opposite effect of inducing the abandonment of useful native elements. Here then the problem takes on an economic complexion, and relative costs of importation, local purchase, or home production have to be considered, with inevitable complications for the final decision.