i INTRODUCTION 5 



are not adapted especially for this region do not thrive 

 here. Most of the trees of this region are leafless in 

 the dry season, and trees like the nutmeg and clove, 

 which are not deciduous, but evergreen, succumb at the 

 first dry spell. In this region the annual field crop 

 spices coriander, cumin, chilies are commonly grown, 

 as well as the rhizomatous ginger and turmeric, which 

 in this climate lose their leaves during the dry spell. 

 Some of the tropical spices, such as capsicums and 

 ginger, have a wider cultivation area than most of the 

 others, and go almost outside the tropical area, but on 

 the whole the areas of successful cultivation are limited. 

 It is rather remarkable that so large a proportion of 

 the spices of the tropics are successfully grown on islands 

 only, or in close propinquity to the sea. Among these 

 are nutmegs, cloves, vanilla, clove barks, and perhaps 

 we may add cinnamon and cardamoms as island plants. 



SOILS 



The various soils suited for the different spices are 

 mentioned under their respective headings. There seems 

 to be increasing evidence that with most plants the 

 physical characteristics of the soil are more important 

 than its chemical constituents. Its water capacity, 

 permeability, and capillary conduction or power of 

 absorbing water, are its most important characteristics. 

 Different crops require different degrees of moisture or 

 dry ness. Most, however, of the plants described in 

 this work require a greater average moisture in an 

 accessible and utilisable form than the plants of colder 

 climates, as their natural habitat is in the wetter part 

 of the tropics. Plants have a great power of adapta- 

 tion to surroundings, though at the same time there is 

 a limit to their endurance. In soil where it cannot 

 obtain its food and water in sufficient quantity a plant 

 becomes pale and weak. The leaves show an unmistak- 

 able yellow tint instead of the rich green, whether light 



