Tropical Forests 



to the exhausted and languid explorer unless he happens 

 to be a botanist. Then of course he is interested and 

 busy from morning to night, for a lifetime would be in- 

 sufficient to understand and appreciate all the problems 

 that perplex him. 



The characteristic products of such jungles are not 

 very many. The rubber vines of Africa (Landolphia sp.) 

 and the various rubber trees and creepers of South 

 America, the guttapercha and rubber of the East Indies 

 are by far the most important economically. 



The peculiar white juice or latex which exudes from 

 the stems of these Apocynaceae, Asclepiadaceae, Moraceae, 

 &c., contains caoutchouc, resins, and other ingredients. 



This latex is of great importance to the plant. It is 

 poisonous, and is so arranged in a network of internal 

 tubes and channels that any cut or wound will neces- 

 sarily result in a plentiful flow of latex to the injured 

 place. 



Trees denuded of rubber by the natives were noticed 

 by Bates to have been stripped of their leaves by 

 the parasol ant and probably destroyed. Upon any 

 wound the rubber will coagulate, and its elasticity and 

 poisonous and resinous characteristics make it invalu- 

 able to cover over the scars and to prevent insects, 

 fungi, or bacteria from entering. If one disregards a 

 few exceptional cases, rubber and guttapercha plants 

 are confined to and invariably found in wet-jungles. 



The valuable Hevea of Brazil seems to belong to the 

 great stretch of forest country which is regularly inun- 

 dated by the annual flood of the Amazon, and which 

 is specially remarkable for its extraordinary ant-plants. 



In Africa it is the Landolphias which form the main 

 supply. 



In both Brazil and Africa the rubber is chiefly a 

 wild jungle product, obtained by native collectors who 

 are utterly unable to foresee or provide against the 



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