163 



pecially in Brazil and in adjacent countries of Sou'h America, and pro- 

 bably means that the natural supply of rubber will never entirely 

 cease, bnt will gradually become the basis for the development of sci- 

 entific forestry in the Tropics. There is, however, no probability that 

 any large proportion of the present producing areas will become perma- 

 nent sources of supply, and the cultural production of rubber well de- 

 serves the serious consideration it is now receiving in all agricultural 

 regions of the Tropics. 



Rubber culture is no new or recent proposition, since beginnings 

 were made nearly three decades ago. With un annual plant twenty 

 years of experience would teach us much, but for dealing with long- 

 lived trefs that period is very short, and it need not be a matter of 

 surprie that rubber culture is still in the experimental stage Many 

 cultural mistakes are still made with plants that have been in domes- 

 tication for thousands of years, and the failure of the first attempts with 

 rubber might have been predicted simply on the grounds of piobability. 

 Nevertheless, a distinct period of discouragement resulted, the effects of 

 which are still felt and will doubtless remain until more detailed know- 

 ledge makes plain the possibility of avoiding the obstacles previously 

 encountered. 



Progress in practical matters as well as in purely scientific subjects 

 depends much upon theories. On the failure of the first experiments, 

 the theory that rubber trees could be profitably cultivated was discarded 

 by many who came to the conclusion that planted trees will not pro 

 duce rubber. This view is by no means extinct, especially among those 

 who have abandoned rubber planting in disgust An adverse opinion 

 of this kind is popular with some because it serves as a general expla- 

 nation of failure and spares the annoying suggestion of cultural errors 

 and oversights. 



Like other members of the vegetable kingdom the performances of 

 rubber trees have been found to deptjnd upon the conditions under 

 which they grow, whether planted or self sown, unless they were in- 

 jured in planting. In the American Tropics and in the East Indies 

 the possibility of the cultural production of rubber has been demon- 

 strated. This fact is giving the pendulum the return swing in the di- 

 rection of sanguine expectations, and the assurance that rubber can be 

 produced culturally is too often taken as a verification of the original 

 estimates of yields and profits in spite of the fact that some of these 

 have been disavowed by their authors. A future of easy prosperity for 

 the rubber planter is held to be assured, and the opinion that rubber 

 culture is still experimental is resented as blindly conservative. 

 The lesson of the former miscalculation is forgotten by the new 

 generation of promoters, and the fact that rubber trees have been 

 found to thrive in a given locality is taken as sufficient evidence that 

 they will meet even the most reckless estimates of productiveness 

 and profits. The opening of large plantations under untried conditions 

 in Porto Rico and the Philippines is advocated, and the investing pub- 

 lic is assured, in effect, that the returns from rubber culture are to be 

 so grea<i that the exercise of ordinary agricultural skill and business 

 caution is unnecssary, though the fact remains that a large measure of 

 both is likely to be required if the numerous unsolved problems of the new 

 industry are to be overcome without ruinously expensive experiments. 



