THE AFRICAN RUBBER VINES 



199 



The total yield of rubber from this vine was, therefore, 

 63 grains, of which 45 grams were obtained by beating 

 the bark. 



An important series of experiments has been made 

 with L. owariensis vines at the Botanic Gardens at Eala 

 by M. Seret, the Director, in order to determine the yield 

 of rubber obtainable from them. In these experiments 

 the vines were severed at about 3 ft. from the soil, and 

 the stems cut into pieces from 12 to 20 in. long. Tlie 

 latex was allowed to drain from the pieces of stem and 

 was afterwards coagulated. The portions of stem were 

 collected, dried for three weeks, and the rubber remaming 

 in the bark was extracted by beating. The following 

 table summarises the results which were obtained : 



L.^USfDOLPHIA OWARIENSIS ViNES 



It will be seen that in experiments 2, 3, and 4 the 

 yield of rubber obtained by beating the bark was very 

 much greater than that obtained from the latex. In 

 the first experiment, however, the yield of rubber from the 

 bark was less than that obtained from the latex, and an 

 experiment at Bena Dibele gave a similar result, as 

 follows : 



31. Seret also conducted an experiment on a large 

 L. owariensis vine growing in the forest, using (1) the 

 main stem, (2) the branches, and (3) the root. The prin- 



