In applying these principles to Africa it is necessary to take account of the natural division of the continent into distinct economic zones. Immediately under the equator is a wide area of heavy rainfall and dense forest. The rapidity and rankness of vegetable growth renders the region unsuited to agriculture. But the plentiful streams abound in fish and the forests in animals and fruits. The banana and plantain grow there in superabundance, and form the chief diet of the inhabitants. This may be called, for convenience, the banana zone. To the north and south of this zone are broad areas of less rainfall and forest, with a dry season suitable to agriculture. These may be called the agriculture zones. Still further to the north and south are areas of very slight rainfall and almost no forests, suitable for pasturage. Here cattle flourish in great numbers. These may be called the pastoral zones. These zones stretch horizontally across the continent except in case of the cattle zones, which, on account of the mountainous character of East Africa, include the plateau extending from Abyssinia to the Zambesi river. Each of these zones gives rise to different types of men, and different characteristics of economic organization, of family life, government, religion, and art. In the banana zone nature is extremely bountiful. The people subsist mostly upon the spontaneous products. A small expenditure of effort will support a vast population. Agriculture is very little practiced. Here the effort to live would seem to be easier and more agreeable than in any other part of the world, so that man would not be under pressure to enslave his kind. But alas, the work of gathering and transporting the fruits, of the preparation and cooking them, as well as the bringing home and cooking of the game, the building of houses, etc., is not altogether pleasant. It is uninteresting, and the heat and the humidity of the climate render it almost insupportable in certain seasons and hours of the day. The repugnance to labor of tropical people, whether natives or white immigrants, is proverbial. Every one in the banana zone, therefore, seeks to shift his burden upon another. As a first resort, he unloads it upon his wife, and she, finding it grievous, cries out, and he then relieves her by procuring additional wives. This kind of wife-slavery suffices for the support of the population in this zone, but in the case of families of rank, who have been accustomed to some degree of luxury, other helpers are needed, and these form a class of domestic slaves. Now, in this zone, the climatic conditions not only render labor disagreeable but tend to curb aspiration, so that people do not acquire a taste or demand for products which minister to the higher nature. Lassitude keeps the standard of living down to a low level. Hence, in this zone the labor of women suffices, for the most part, for the maintenance of the population.