36 THE PRINCIPAL RUBBER- YIELDING PLANTS 



The Imperial Institute Selected Reports on Rubber atid 

 Gutta Percha contain (pp. 348-51) analyses of a number of 

 products derived from other species of Ficus, such as 

 Ficus comosa, F. indica, and F. rubra, which are, however, 

 of no commercial interest. 



8. Bleekrodea tonkinensis, Dub. and Eberh. This tree 

 occurs in Tonkin, and is stated to yield rubber of good 

 quality which is collected by the natives. The base of 

 the tree is tapped and the latex is coagulated by boiling. 



III. ASCLEPIADACEAE 



9. Cryptostegia spp. 



(a) Cryptostegia grmidiflora, R. Br. This species of 

 Cryptostegia occurs in Madagascar, Reunion, and India, 

 and has been introduced into Mexico and the Bahamas 

 where it now grows freely. It is a climbing plant or 

 vine and yields rubber of good quality, which, however, 

 is very difficult to obtain by tapping. 



Several samples of the rubber from India and the 

 Bahamas have been examined at the Imperial Institute, 

 and the following analyses may be given : 



It will be seen from these figures that the rubber is of good 

 quality if carefully prepared. Analyses of other specunens 

 of the rubber from India are given in Imperial Institute 

 Selected Reports on Rubber and Gutta Percha, pp. 400-2. 



(6) Cryptostegia madagascariensis, Boj. This plant, 

 which is stated to grow sometimes as a vine and some- 

 times as a shrub, is the source of the " lombiro " rubber 

 of Madagascar. The yield of rubber from the plant is 

 small and the product is of inferior quality, being usually 

 soft and deficient in elasticity. It is stated that the 

 rubber is employed for some special purpose in Germany 

 for which it commands an increased price. 



10. Raphioiuicme utilis, Brown and Stapf. 



This recently discovered rubber plant is a native of 



