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THE AFRICAN RUBBER VINES 



Landolphia Dawei. — This vine furnishes a large yield 

 of rubber, but no results of tapping experiments are 

 available. Dawe has stated that in Uganda vines of this 

 species will give, when carefully tapped, much more 

 than 8 oz. of dry rubber per annum ; whilst Chevalier, 

 from his experience of the vine in West Africa, considers 

 that when ten years old it wiU yield 500 grams (Tl lb.) of 

 dry rubber per annum. 



In Uganda a large vme wiU give as much as a quart 

 of latex at one tapping, and, according to the natives, the 

 vines can be tapped three times a year without injury. 



Clitandra Arnoldiana. — The yield of rubber obtainable 

 from this vine was also investigated by M. Seret at Eala 

 by the same method as was adopted in the case of the 

 Landolphia vines. The vine was severed at about 3 ft. 

 above the soil and detached from the supporting tree ; 

 the stem was then cut into pieces and the latex allowed 

 to drain out as completely as possible ; afterwards the 

 stems were dried, the bark stripped off, and the rubber 

 extracted by beating. The results obtained are summar- 

 ised in the following table : 



Further experiments were made on cultivated vines 

 growing at Eala and at Bamania with the following 

 results : 



