PARA RUBBER, 61 



It cannot be doubted that in a system of small oblique or V 

 cuts a considerable amount of labour is involved in fixing and ad- 

 justing a very large number of collecting tins at the base of each in- 

 cision, and though this system cannot be regarded as drastic and 

 harmful to the tree, it is likely to be superseded by others when 

 planters have to find labour sufficient to regularly tap large acreages 

 of mature rubber. In the oblique or V incisions a chisel or paring 

 knife is commonly used, though most of the implements previously 

 described may be used in this system. 



In the V method it has been noticed that when the sides of four 

 adjacent V cuts are drawing on an area of 60 to 80 squai'e inches, the 

 flow of milk after two months' tapping becomes very poor. The 

 photograph here reproduced on Plate 11, Series A, shows the V cuts 

 after tapping for ten weeks every alternate day. There was. at the 

 time the photograph was taken, still plenty of space between the ad- 

 jacent incisions, but the flow of milk was too small to warrant fur- 

 ther tapping. This method obviously cannot be carried out for the 

 same length of time as the half or full spiral curves, because the 

 oblique cuts sooner or later interfere with one another and draw on 

 the same limited area. Four trees, tapped similar to that indicated 

 on Plate 11 by the use of a paring knife and the spur, gave 10 lb. 14| 

 oz. of dry rubber from the 29th June to the 6th September, 1905. 



In some countries the exudations from trees are obtained by mak- 

 ing incisions in the form of inverted V's, but such a method has no 

 advantage in connection with the tapping of Para rubber trees. 



Herring-Bone System. 



This consists of a series of short, parallel, oblique incisions connect- 

 ed with a vertical one ; the incisions may be on one or both sides of 

 the vertical channel, and vary in length from about 4 to 12 inches. 

 The illustrations on Plate 12, Series A, show both systems at the 

 beginning. The vertical channel usually varies from 1 to 6 feet in 

 length, and is usually sufficiently wide to conduct the latex from a 

 dozen oblique cuts ; the tin placed at the base is the only receptacle 

 for the latex. The advantage of this system lies in the minimum 

 labour required for collecting operations, but there are many reason- 

 able objections against the waste of tissue which occurs when a ver- 

 tical channel of considerable depth and width is made. Though 

 it is considered to be more drastic than the foregoing method, this 

 system is in use on several estates in Ceylon, and has at times been 

 adopted with success by planters and officials in the Malay 

 Peninsula, India, and Africa. 



After the original oblique incisions have been made they are 

 re- opened by paring away the lower surface, this operation being 

 continued until the whole of the tissue between the lines is used up. 

 Any of the knives described may be used for these operations. 



When the herring-bone system is used there is no necessity to fix 

 spouts at the base of each incision, as the latex flows down the groove 

 in the bark. Experiments have been made with conducting channels 



