the tree thus suffers, must necessarily extend to the quantity and 

 quality of the supplementary latex. 



I have already pointed out, that under certain circumstances, 

 even incomplete girdling incisions, which only interrupt the 

 continuity of the cortex and of the outer layer of bast, may sooner 

 or later have a deleterious effect on the tree, on account of the 

 partial interruption of the circulation of nutritive substances. 

 If such an injury occurs, it is obvious, for reasons given above, 

 that it will not be without great influence on the renewal of latex 

 below the spot operated upon. It will have an influence on the 

 reproduction, all the greater the more latex has exuded, and 

 will therefore have to be replaced. A sufficient re-flow of latex 

 through the few vessels that may possibly still remain intact in 

 the inner bast, will be all the more impossible the younger and 

 more undeveloped are these laticiferous vessels. 



In summing up all we have been considering in this chapter, 

 based as it is on well-known physiological data, I think we can 

 form the following conclusion, that in rubber trees (as in other 

 trees), cuts made very deep in the cortex and in the bast, are apt, 

 sooner or later, to disturb greatly some very important vital 

 functions of the tree, and consequently retard below the girdle 

 the renewal of cortex and of the latex that has exuded ; all the more 

 the deeper and more extensive these cuts are, and the longer the 

 period is, which will be required for the restoration of the severed 

 parts, because the reservoirs below the girdle will become 

 exhausted and a scarcity of food must occur in some parts of the 

 tree. The younger the tree, the sooner the injury will be 

 noticeable. 



D. Problems for my Experiments. 



How can we utilise this conclusion, in order to determine the 

 value of the various tapping methods ? Does tapping really 

 interfere with the vitality of the tree so much as, sooner or later, 

 to damage it seriously, and hinder the renewal of latex of good 

 quality? In order to decide these questions, it will IK- necessary 

 firstly to glance at the anatomical structure of the Hevc-a tree. ;m<l 

 secondly, to consider the demands made in actual practice on the 

 tapping cuts, so that a sufficiently remunerative yield of latex 

 can be obtained. 



As regards the anatomy of the Mem o| Ile\e,i, it will lie 



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