500 ANNUAL BEPORT SMITHSONIAN INSTITUTION, 1931 



crops that could be grown in the United States. The importance of 

 home production of food in Europe, however, is now being recog- 

 nized; one result of this will be a more careful consideration in 

 America of a home market for food products. The time may soon 

 come when we shall be willing to lay aside our remaining European 

 prepossessions and face the necessity of making the most of our own 

 country. With this viewpoint we shall cooperate more construc- 

 tively with our American neighbors who are facing the same prob- 

 lems of utilizing tropical plants as the basis of economic and social 

 advancement. 



Neglect of such considerations is responsible for the present situa- 

 tion in the United States in regard to rubber, which undoubtedly 

 could be produced as well or better in tropical America than in the 

 East Indies. The history of the rubber development shows that 

 much has depended on mere accident, through lack of interest. The 

 accident whereby American rubber companies began with a different 

 tree in Mexico resulted in discouragement at a critical stage when 

 the East Indian plantations were beginning to be successful, so that 

 valuable time has been lost. It was supposed that the world's need 

 of rubber would soon be supplied, and this mistake is now being 

 repeated. 



The discovery of a suitable tapping method for the Hevea tree 

 in the East Indies also was accidental, except that the conditions 

 for making such a discovery had been provided b.y the introduction 

 of the tree. If the tapping method for Hevea had not been dis- 

 covered, the cultivation of Castilla in Mexico and Central America 

 would not have appeared as a complete failure. The rubber prob- 

 lems have been studied but little as yet, and practical ways of 

 utilizing the Castilla tree or other rubber-producing plants may 

 still be found. Mechanical extraction of rubber instead of the 

 laborious tapping operation is the line of improvement to be ex- 

 pected, but different extraction processes, as well as different cul- 

 tural methods, will probably have to be developed for each of the 

 producing species. 



The lesson is that in each country stocks of the different kinds 

 of rubber trees or other useful plants should be available to furnish 

 ample supplies of seed or propagating material for those who are 

 interested in determining the possibilities of the new plants. The 

 history of rubber affords many illustrations of the general require- 

 ment for progress in agriculture— namely, that the facts must be 

 learned by actual experience and familiarity with the plants. There 

 is no way to prophesy in advance that a plant will not grow in a 

 new country, or that new uses will not be discovered. Nobody 

 would have guessed that the Hevea tree would thrive in Florida or 



