167 



A special chisel, made by Mr. Jowett at the suggestion of 

 the author of the paper, has been successfully used in Trinidad, 

 and a specimen was shown at the meeting. 



THE METHODS OF TAPPING CASTILLOA RUBBER TREES 

 IN MEXICO AND THE YIELD OF RUBBER WHICH THE 

 TREES FURNISH. 



By ASHMORE RUSSAN, 



Director of the Soconwsco Rubber Plantations, Ltd,; London 

 Director of La Zacualpa Plantation Company. 



[ABSTRACT.] 



The paper deals : 



(a) With the cultivation of Castilloa rubber on La Zacualpa 

 and other plantations in the District of Soconusco, State of 

 Chiapas, Mexico, and also with a plantation in the State of 

 Oaxaca, Mexico. 



(b) With the methods employed in tapping cultivated 

 Castilloa rubber trees in Mexico and the tapping-knives used. 



(c) With the yields of rubber obtained on a commercial scale 

 from cultivated trees of different ages, and with the reputed 

 yields from wild trees. 



(d) With the yield of cultivated Castilloa rubber trees in 

 comparison with that of Hevea brasiliensis, and shows- why 

 the Castilloa may be more suitable for cultivation in Mexico 

 than Hevea brasiliensis, owing to the deficiency of labour. 



(e) With experiments which have been made to increase the 

 production, and points out that, in the author's opinion, this 

 can only be done by better cultivation. 



(/) With the different species of Castilloa to be found in 

 Mexico and Central America from the point of view that the 

 Castilloas are all of the same species, and that the difference in 

 yield, etc., is probably due to environment. 



[DISCUSSION.] 



Sir THOMAS HOLDICH : Mr. Chairman I can add nothing 

 really valuable to what Mr. Russ'an has said. In regard to 

 Mexico, no one can speak with such authority as he can. But 

 with reference to the varieties of the Castilloa tree, I would like 

 to ask Profes'sor Dunstan whether such varieties of Castilloa 

 occur. I have seen it stated, though I cannot say positively 

 where, that no less than seven different kinds of Castilloa are 



