RUBBER 



703 



with porous cloth bottoms. Coagulation may be hastened 

 by the addition of dilute acetic or sulphuric acid, or an 

 aqueous extract of the " moon " vine (Ipomoea bona- 

 nox). 



In Trinidad and Tobago Castilloa has not been grown 

 as a separate cultivation. It was recommended some 

 thirty years ago as a shade tree for cacao, and it has been 

 tried for that purpose only over small areas. Under these 



DIAGRAM SHOWING METHOD OF TAPPING CASTILLOA TREES. 



conditions it has not given, and could not be expected to 

 give, the best results; and the yield of rubber from our 

 trees may be considerably less than that from trees grown 

 under different conditions. The best results that have 

 been obtained in Tobago from young trees tapped for 

 the first time to a height of 20 ft. for half the girth of the 

 tree are for an average of 10 trees 10*8 oz., and for 288 

 trees a little over 5 oz. for a single tapping, and 3*4 oz. 

 for a second tapping four months later. 

 45 



