The products of the oil palm and especially palm kernels have been in increased demand for edible purposes, the war having led to a far greater use of margarine and similar materials. The perfection of processes for the better extraction of palm oil from the fruits which had nearly reached success at the outbreak of war now awaits completion, when a large additional source of edible oil will be available. In the meantime the trial cultivation of this palm in other countries has been attended with remarkable success, the growth of the palm in plantations having been entirely satisfactory and furnished yields of oil which exceed those given by the wild palm in West Africa. The Dutch East Indies, where large plantations have been made, and also British Malaya, where similar enterprise has been shown, may before long be formidable rivals to West Africa in the production of palm kernels and palm oil. The neglect in West Africa of the wild trees, the imperfect methods followed in extracting the palm oil, and the large number of palms unutilised are questions which now need renewed attention, and in fact the entire subject of the development of the palm-oil industry in West Africa demands the most serious study in all its aspects if the industry is not to be supplanted by the enterprise of other countries. In this and other directions where the continuous acquisition of new knowledge is requisite, it is satisfactory to learn that the staffs of the Agricultural Departments in West Africa are to be extended and better remunerated. In addition to this step, and perhaps equally important, will be the increased interest and activity of those merchants and manufacturers who utilise the raw materials of the country, and to whom the commercial development of West Africa has hitherto owed so much. There are many other subjects which, it will be seen from the new edition of this book, have come to the front since the first edition appeared, and now need increased attention. The only rubber tree which has survived as a producer in the years of strenuous competition is _Hevea brasiliensis_, from which Para rubber is obtained. Successful plantations of this tree have been established both in the Southern Provinces of Nigeria and in the Gold Coast, and from the former commercial rubber is now being produced of quality equal to that of the rubber plantations of the East. The Gold Coast has become the chief cocoa producer of the world, but it is clear that unremitting care and attention in connection with the cultivation and the preparation of cocoa in that country will be necessary if that supremacy is to be maintained.