ASSIMILATIVE AND SECONDARY RUBBERS 131 



The Guayule industry is practically in the hands 

 of two non-competing American companies, who, 

 besides controlling output, have effectually cornered 

 all the known sources of supply. 



The latex of Parthenium argentatum is found in 

 the form of very small granules throughout the 

 tissues of roots, stems, and branches. To obtain the 

 product, therefore, it is necessary to appropriate the 

 whole of the " heart " of the shrub, which is done 

 by the wholesale removal of it save the few sur- 

 rounding racemes, from which spring the new plants 

 in the course of time. 



Although the manufacture of rubber from Guayule 

 may be said to be a new industry, the Mexican Indian 

 has been accustomed for hundreds of years to utilise 

 it for making his drumsticks and the " catch-balls " 

 of the native village greens by chewing out the gum 

 from the bark. 



Modern methods of abstraction are known only to 

 the firms intimately associated with Guayule manu- 

 factures. The factories at Barras, Torreon, Saltillo, 

 and Cedros are right in the heart of the Guayule 

 country, the total area of which cannot be less than 

 6,000,000 acres. Notwithstanding the enormous 

 yearly consumption of the plant, there is no danger 

 of a Guayule famine for many years to come. The 

 factories are consuming at present about 150,000 tons 

 of the shrub yearly, and the visible supply is not less 

 than 200,000,000 tons ! 



Jelutong or, as it is sometimes called. Pon- 

 tianak, after the name of the port of shipment 

 is derived from a large tree indigenous to the 



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