THE PARA RUBBER TREE 123 



the growtli is rapid and satisfactory. After an interval 

 of four years the renewed bark has been found to give 

 as good a yield of latex as the original bark.* 



Besides the half-hcrringbonc method described above, 

 a number of other systems have been tried for tapping 

 Hevea trees. The principal of these are: (1) the double 

 herringbone system, which is sometimes employed on 

 large trees ; (2) full-spiral and half-spu-al incisions, which 

 furnish large yields of latex and rubber, but have now 

 been generally abandoned as being too drastic for con- 

 tinuous use, especially in the case of young trees ; (3) 

 large or small V incisions, which necessitate the fixing 

 of a cup at the base of each V and therefore involve a 

 large amount of labour ; (4) basal V or Y incisions or 

 oblique cuts for tapping the base of young trees which 

 are not large enough to be tapped to a height of 6 ft. ; 

 and (5) vertical incisions. In all these systems, except 

 the last, it is usual to reopen the cuts by paring a thm 

 slice from the lower edge as previously described. 



At one time a combined method of paring and pricking 

 was adopted for reopening the incisions and a number of 

 special forms of pricker were introduced for the piu'pose. 

 These prickers have, however, fallen into disfavour, as it 

 has been found that their continued use often leads to the 

 formation of excrescences from the wood, and also that in 

 some cases the renewal of bark over the pricked area is not 

 satisfactory. In consequence of these facts, the reopening 

 of the incisions is now usually done by paring only. 



Collection of the Latex. — The collecting-cups used on 

 rubber plantations v>ere at first made of tin, iron, or steel, 

 but such cups are not entirely satisfactory as they quickly 

 become rusty and are then difticult to keep clean. In 

 order to obviate this drawback, aluminium or enamelled 

 iron cups have been tried, and, more recently, glass, 

 earthenware, and paper cups have been largel}^ adopted. 



A little water is sometimes placed in the cups in order 

 to preserve the latex in a liquid condition until it can be 

 collected and carried to the factory. In some cases, 

 when the latex is thick and does not run freely, a system 



* For the results of tapping experiments on Para tree see Circulars 

 and Agricultural Journal of Royal Botanic Gardens, Ceylon ; Agricultural 

 Bulletin of Straits and Federated Malay States ; Agricultural Bidletin 

 of Federated Malay States. 



