216 THE CENTRAL AMERICAN RUBBER TREE 



in a calabash or in a cavity in the soil lined with a large 

 palm-leaf. Further incisions are made between the 

 original series or across them, with the result that the 

 trunk ultimately presents a very scarred appearance. 



(2) Large V-shaped incisions are made about 3 ft. 

 apart, the two cuts forming the V extending nearly round 

 the trunk. A small piece of bent iron or a leaf is usually 

 inserted in the bark at the base of the V m order to serve 

 as a spout for directing the latex into a vessel placed 

 below. 



(3) Large spiral incisions extending right round the 

 trunk are sometimes employed. 



Formerly many of the trees were cut down in order 

 to obtam the rubber. 



The objections to the native methods of tapping are 

 that the incisions are made much too deeply, penetrating 

 the wood in nearly every case ; that the trees are tapped 

 too frequently ; and that the whole of the trunk is tapped, 

 the higher portion being reached by means of rough 

 ladders. This severe treatment has resulted in the 

 destruction of many of the wild trees. 



Various methods are employed by the natives of 

 Central America for the coagulation of Castilloa latex. 



In Mexico coagulation is brought about by adding to 

 the latex an infusion of the " Morning Glory," or " Moon " 

 vine, Ipomoea Bona-nox, L. [Caloniction speciosiim). 



The stems of this plant are bruised and allowed to stand 

 in water for a short time ; the liquid thus obtained 

 quickly coagulates the latex. The rubber prepared by 

 this method is made into large slabs or cakes, which are 

 very porous and retain in their cavities a large amount 

 of the dark mother-liquor of the latex. This liquid 

 contams a considerable percentage of protein and is 

 consequently liable to undergo fermentation with the 

 development of a very objectionable odoiu-. 



Another method which has been used in ]\Iexico is to 

 spread a thin layer of latex on the large leaves of a species 

 of Calathaea ; this is allowed to dry in the sun and then 

 a fresh layer of latex is added, the process being repeated 

 until a sheet of rubber about ^ in. thick is obtained. Two 

 of the leaves then have their rubber-covered surfaces 

 pressed firmly together, when the rubber adheres to form 

 a single sheet, from which the leaves can be easily stripped. 



