In the next step, every fourth tree in the fourth or fifth row of cacao may be omitted and its place filled by a permanent shade tree. The planting of shade trees or "madre de cacao" among the cacao has been observed from time immemorial in all countries where the crop is grown, and the primary purpose of the planting has been for shade alone. Observing that these trees were almost invariably of the pulse or legume family, the writer, in the year 1892, raised the question, in the Proceedings of the Southern California Horticultural Society, that the probable benefits derived were directly attributable to the abundant fertilizing microörganisms developed in the soil by these leguminous plants, rather than the mechanical protection they afforded from the sun's rays. To Mr. O. F. Cook, of the United States Department of Agriculture, however, belongs the credit of publishing, in 1901, [4] a résumé of his inquiries into the subject of the shades used for both the coffee and the cacao, and which fully confirmed the previous opinions that the main benefit derived from these trees was their influence in maintaining a constant supply of available nitrogen in the soil. That cacao and its wild congenors naturally seek the shelter of well-shaded forests is well established; but having seen trees in these Islands that were fully exposed at all times showing no evidences of either scald, burn, or sun spot, and in every respect the embodiment of vigor and health, we are fully justified in assuming that here the climatic conditions are such as will permit of taking some reasonable liberties with this time-honored practice and supply needed nitrogen to the soil by the use of cheap and effective "catch crops," such us cowpeas or soy beans. Here, as elsewhere, an Erythrina, known as "dap-dap," is a favorite shade tree among native planters; the rain tree (Pithecolobium saman) is also occasionally used, and in one instance only have I seen a departure from the use of the Leguminosæ, and that in western Mindanao, there is a shade plantation composed exclusively of Cananga odorata, locally known as ilang-ilang. While not yet prepared to advocate the total exclusion of all shade trees, I am prepared to recommend a shade tree, if shade trees there must be, whose utility and unquestioned value has singularly escaped notice. The tree in question, the Royal Poinciana (Poinciana regia), embodies all of the virtues that are ascribed to the best of the pulse family, is easily procured, grows freely and rapidly from seed or cutting, furnishes a minimum of shade at all times, and, in these Islands, becomes almost leafless, at the season of maturity of the largest cacao crop when the greatest sun exposure is desired.