TAPPING 65 



graduated as to prevent damage to the cambium, but 

 hitherto nothing of a practical description has been 

 evolved. 



Experiments with the curved gouge, similar to that 

 used so successfully in the Orient, have not given satis- 

 factory results. The two principal reasons why this is 

 the case are that the trunks of the trees have been so 

 much injured by the machadinho in past years that any 

 form of excision tapping is necessarily slow over the 

 rough renewed bark, and consequently a collector taps 

 only half the number of trees ; and because the excision 

 of the cortex renders the tree liable to attacks of cambium 

 disease, resulting in a weakening of the latex. Another 

 and serious drawback to gouge tapping is that constant 

 and competent supervision is required to obtain the full 

 benefits of the system, and this factor is unattainable 

 under present circumstances in the Amazon Valley. 

 Even on planted and also virgin forest trees the use of 

 the gouge is impracticable if it leads to damage from 

 cambium rot, as was the case in the experiments tried 

 in 1912 and 1913 ; and the fact that a greater yield of 

 latex per tree can be obtained by the application of 

 the herring-bone system is insufficient compensation 

 if this additional quantity is of distinctly inferior 

 quality. 



The established custom is for the collectors to supply 

 the machadinhos, latex cups and cans, and all other 

 implements required for their work. The charge made 

 for the small machadinho heads in general use is two 

 shillings and eightpence each, at least four times the 

 proper retail value. A proportionately extortionate rate 

 is made for all other articles the collector may require. 

 5 



