42 THE RUBBER INDUSTRY 



connection with the future progress of the rubber 

 industry. It is not so much on account of the actual 

 damage caused by this disease at present that it is to 

 be dreaded, but for the fact that recent experiments 

 demonstrate that it breaks out in virulent form when 

 Oriental methods of tapping are attempted. This 

 means that the herring-bone system cannot be em ployed 

 in order to obtain a greater yield of latex with no 

 additional labour force, and by such means reduce 

 substantially the ultimate cost of production. It will 

 be explained at a later period why this condition is 

 such a very important factor in the prosperity of 

 the industry. The disease occurs on trees tapped 

 with the small axe (machadinho) as well as on those 

 worked with the gouge on the herring-bone system in 

 vogue in the Orient ; it is neither so apparent nor so 

 destructive on the former, on account of the fact that 

 the overhanging flap of the axe-cut covers the incision, 

 and because the scrap is not collected from the wound, 

 but allowed to remain and form a protective shield 

 against atmospheric action. Hence, in the case of 

 machadinho tapping the rot remains dormant for all 

 practical purposes, while with the excision of the bark 

 when the herring-bone system is followed no conceal- 

 ment of the disease is possible. 



Experiments carried out for some months in 1913 on 

 trees in the districts adjoining the Rivers Madeira and 

 Purvis, and on a smaller scale near Manaos, with the 

 full herring-bone, half herring-bone, and single V 

 systems, showed that the rot set in on the tapped 

 surface after about one inch of bark had been removed. 

 The tool used for this work was the bent gouge, which 



