214 CACAO 



therefore the presence of such food has been termed the 

 " incidental increment." Such incidental supplies do not 

 appear to be taken into account by the chemist. That 

 they exist has been proved by several examples under 

 our notice. 



It is well known that a large amount of epiphytic growth 

 occurs in tropical areas, especially among plants belonging 

 to the order Bromeliacea. These plants cover the branches 

 and stems of trees, and are especially plentiful in cacao 

 estates, both on the shade trees and on the cacao-tree itself. 



A large shade tree having to be cleaned of one of these 

 plants, a sample was taken and sent for analysis, when the 

 following was given as the result : Water, 78* 13 per cent. ; 

 ash, 0-89 per cent. ; organic matter, 20-98 per cent. Now, 

 these plants are so constructed as to maintain water in the 

 axils of their leaves, some holding as much as a quart at a 

 time. In this water insects of numerous kinds drown, and 

 vegetable matter is deposited, and an examination of a 

 sample of it showed that it contained total solids 0-184 per 

 cent., organic matter 0-160 per cent., ash 0-024 per cent. 

 This result may appear small, but when it is considered 

 that the water contained in the plant overflows with 

 every shower it is seen what a large quantity of manurial 

 matter may be thrown upon the land during the course of 

 a year. 



The plants themselves also are constantly upsetting and 

 freeing themselves from the branch, and falling to the 

 ground, adding, as will be seen, some 21 per cent, of their 

 weight of organic matter to the soil on which they fall. 

 Phosphoric acid is also required, say 0-5 drachms per tree. 

 The bones of a snake, bird, or small rodent would furnish 

 the required amount. That it must get there we know, 

 as the produce contains it ; but there is at present no way 

 of estimating or measuring the quantity, although the 

 planter can fairly calculate upon a constant supply. When 

 the want of " incidental increment " makes itself apparent 

 by exhaustion, the planter must then adopt artificial 

 supply, but not until the want of it is plainly proved. 



