42 SHADE IN COFFEE CULTURE. 



tions. On the contrary, it is extremely probable that the beneficial 

 effects resulting from shade are quite apart from the shadow cast upon 

 the coffee tree. 



The beneficial effects connected with shade arise from the protection 

 afforded against drought, erosion, and winds. The planting of shade 

 trees for these purposes is accordingly determined by local conditions 

 of climate and soil, and furnishes no reason for the general planting 

 of shade trees. 



In regions not affected by injurious climatic extremes the planting 

 of shade trees is justified from the cultural standpoint only by the 

 increased fertility imparted to the soil by means of the nitrogen-fixing 

 root tubercles of leguminous species. This view has not been made 

 the subject of experimental demonstration, but it seems to accord with 

 all the facts thus far ascertained. 



The benefits of leguminous fertilizing are quite apart from the 

 shading of the coffee, and under suitable cultural conditions are also 

 to be secured from shrubs and herbs belonging to the same natural 

 family. 



The relative utility and availability of the various shade trees and 

 soiling crops is a subject of vast importance in coffee culture and in 

 other agricultural industries of the Tropics. 



The combinations of such cultures as coffee and cacao with legumi- 

 nous trees and plants of maximum cultural and commercial value afford 

 many complex, scientific, and practical problems bearing upon the 

 rise of mixed farming in the Tropics, and are thus worthy of serious 

 experimental attention. 



LIST OF COFFEE SHADE TREES. 



Some of the cacao and coffee shade trees of South America have been 

 introduced into Trinidad, Porto Rico, and other West Indian islands, 

 and one of the favorite species in Java came from the Moluccas, but 

 there has been no serious attempt at bringing together even the more 

 prominent American and Asiatic species, much less any systematic 

 effort at investigating the possibilities of the multitudes of arboreous 

 legumes to be found throughout the Tropics. If experiments shall 

 demonstrate that the roots and not the leaves are the parts of the tree 

 which are of primary importance, the selection of leguminous trees 

 for agricultural uses must be approached from a new standpoint, and 

 the results it is impossible to foresee. But in addition to such consid- 

 erations the further possibility of using for shade leguminous trees 

 which furnish valuable wood, fruits, gums, or other products must not 

 be overlooked, since additional returns from such a source would be 

 in the nature of clear profits to the coffee planter. 



As a preliminary to the study of shade trees available for use with 

 coffee and other similar cultures, a collation of the species thus far 

 recorded as having been used for this purpose seems desirable, and a 



