26l 



If these figures represent facts at all general, they lessen very 

 distinctly the prospects of any plans which contemplate the tap- 

 ping of very young trees, and it will be necessary to agree with 

 Dr. Weber that eight years is the minimum age at which a planta- 

 tion can be expected to furnish rubber for the market." 



TAPPING. 

 The following* is a description of a method of tapping the trees 

 in the forests of Nicaragua : 



When the collectors find an untapped tree in the forest they first 

 make a ladder out of the lianas or " vejucos" that hang from every 

 tree. This they do by tying short pieces of wood across them 

 with small lianas, many of which are as tough as cord. They then 

 proceed to score the bark with cuts which extend nearly round the 

 trees, like the letter \ , the point being downward. A cut like this 

 is made about every 3 feet all the way up the trunk. The milk 

 will all run out of the tree in about an hour after it is cut, and it is 

 collected into a large tin bottle made flat on one side and furnished 

 with straps to fasten on to a man's back. A decoction is made 

 from a liana {Caloiiyction spcciosum), and this, on being added to 

 the milk in the proportion of I pint to the gallon, coagulates it to 

 rubber, which is made into round, flat cakes. A large tree, 5 feet 

 in diameter, will yield, when first cut, about 20 gallons of milk, 

 each gallon of which makes 2A- pounds of rubber. I was told that 

 the tree recovers from the wounds and may be cut again after the 

 lapse of a few months ; but several I saw were killed through the 

 large harlequin beetle {Acrocinus longimanus) laying its eggs in the 

 cuts, and the grubs that are hatched boring great holes all through 

 the trunk. When these grubs are at work you canhear their rasp- 

 ing by standing at the bottom of the tree, and the wood dust 

 thrown out of their burrows accumulates in heaps on the ground 

 below. 



That improved methods and tools are to be used for cultivated 

 trees is one of the points on which all the rubber planters agree, 

 but as yet none of the many improvements suggested has attained 

 any popularity, and it is at least doubtful whether any of the 

 devices brought forward at this time is to be looked upon as a 

 practical solution of the problem. Some inventors have worked 

 on the erroneous idea that the rubber comes from the sap, like 

 sugar from the maple, and have thus completely wasted their time. 

 An enumeration of some of the features essential for a good 

 tapping instrument may save further labour on wrong lines. 



The cutting edge must be keen, and must therefore be easy to 

 sharpen. A thick or blunt edge bruises the wood and milk tubes, 

 and this interferes with the flow of milk. 



There should be a means by which the depth of the cut can be 

 regulated, since it is important to cut deep enough to reach the 

 milk and yet not so deep as to reach into the wood, but axes and 

 chisels with shoulders to prevent too deep penetration are not 

 promising because the thickness of the outer bark is variable. The 



* From Bull. No. 49, Bureau o£ Plant Industry. 



