200 TROPICAL AGRICULTURE 



The latex may be coagulated, however, by the gentle appli- 

 cation of heat or by adding an infusion of the leaves of 

 Bauhinia reticulata or of Strophanthus preussii. On planta- 

 tions of Funtumia these methods and "creaming," or diluting 

 the latex with 5 to 10 times its volume of water, are used. 

 Chemical coagulations have also been tried. Spiral tapping 

 and vertical cuts have given the best yield, but the yield of 

 Funtumia rubber varies greatly and is apparently less than 

 that of Hevea trees of the same size. Funtumia rubber con- 

 tains 86.5 per cent, caoutchouc, 0.5 per cent, moisture, 6 per 

 cent, resin, 6 per cent, protein, and I per cent. ash. 



The Central American rubber tree (Castilloa elastica) is a 

 quick-growing tree with soft rather smooth bark and large 

 hairy leaves, 12 to 20 inches long and 5 inches wide. The 

 temporary deciduous branches, sometimes 10 feet long, form 

 on the young trees and later fall off. Permanent branches 

 develop only after 3 or 4 years. The geographical range of 

 the Castilloa rubber tree is from 22 N. in Mexico to Peru. 

 In Mexico the tree occurs chiefly in the States of Vera Cruz, 

 Oaxaca, Chiapas, Tabasco, and Campeche. The Castilloa 

 rubber tree is ordinarily planted at the rate of 100 to 150 per 

 acre. The trees are tappable at the age of 6 or 7 years. They 

 may reach a height at maturity of 175 feet and a diameter of 

 4 feet. The natives of Mexico and Central America tap the 

 Castilloa tree with a machete by the system of slanting cuts 

 or half-herringbone method. V-cuts 8 to 12 inches apart are 

 also much in favor. Spiral incisions and other methods of 

 tapping have also been used by the natives. For coagulating 

 Castilloa latex the natives use heat, ashes, soap, or an infusion 

 of Ipomcea bona-nox. On plantations of Castilloa the methods 

 employed are creaming in large vats or the use of centrifugal 

 cream separators. 



Castilloa trees are commonly tapped only three times an- 

 nually. The average yield is 2y 2 to" 3 pounds per tree per 

 year. Some old wild trees of great size have yielded as high 



