It is also recorded that oil-palm cultivation has been introduced with some success to the natives, in the districts of Lomie and Yaunde, but any “cultivation” by the natives is very simple in nature, consisting merely in the keeping of the stands clear of “bush.” The large decrease in the exports of ivory in recent years is due in great measure to the exhaustion of the stores of ivory hoarded by the natives and the extent of elephant shooting in the past ten years. The exports in 1910 amounted to sixteen tons, valued at £124, and although there was a slight increase of quantity in the following year, the export in 1912 showed a large diminution. The other native products are chiefly djair nuts, shea nuts, kola, and gum arabic, but there has been comparatively little activity as regards the actual cultivation of crops, because of the natural richness of the country in products which enable the inhabitants to buy what they require. The raising of food crops exists, however, for special demands, such as arise near railways, administrative stations and larger towns, and the chief places on the caravan routes and rivers. Near such places the native raises maize, plantains, bananas, cassava, sweet potatoes and ground nuts, as well as sorghum (dura or dari) in the northern districts, and some kola and sesame in isolated places. In several districts a certain amount of tobacco is planted; there is also some little fruit raising, notably in the villages of Ambam. In the highlands of Dschang, and in other places, such as Ebelowe and Yaunde, new crops, such as the English potato, “black bush” beans and turnips, for which the climate seems to be suited, have been introduced. Numerous inhabitants of the districts of Duala and Edea have in recent years laid out farms for the raising of cassava, plantains, maize, yams, and other products. North of the watershed the principal crops are guinea-corn, millet, ground-nuts, cassava, and sweet potatoes; cotton and tobacco are also cultivated by the Chamba pagans, Zumperis and Munchis. The corn is planted in April at the end of the rainy season, the method of cultivation being as follows. The ground is first cleared of weeds and the remains of the last year’s crop. It is then prepared for sowing by digging shallow trenches with a rough kind of hoe, the earth being piled up to form ridges between the trenches. Guinea-corn (_Sorghum vulgare_), the staple food of the country, is planted in these ridges. It grows to a great height, often fifteen to twenty feet, and is harvested in November. Millet is planted in the furrows; it ripens rapidly and is harvested in July. Cotton is ready for picking after December; tobacco and cassava are cultivated during the dry season on the hillsides, the streams being used for irrigation.