43 - 



that by these incisions, vertical strips of bark are preserved for 

 quite a long period of time. I have not obtained information as 

 to how long the tree is rested after each tapping period. 



For practical reasons, I do not believe that estates will 

 revert to a tapping system based on this procedure. It is not 

 very easy to spare the cambium by a method of this description,, 

 neither is it easy to collect the latex, nor does one succeed in 

 deriving the full benefit of the wound response, during the tapping^ 

 operation, nor, finally, in milking the bark as completely, as in 

 practice one would like to do. I am rather of opinion, that estates 

 will have to keep to a system by which at short intervals narrow 

 strips of bark are again and again removed from the spots of 

 tapping. It will hardly be possible to raise any objections based 

 on physiological facts against this universally adopted method. 



If now, after all these considerations, we pass in review the 

 various tapping systems, that in the course of years have been 

 recommended, we come to the conclusion that only very few of 

 them fulfil the requirements I have enumerated, and appear 

 suitable for young plantations. Only those remain for our con- 

 sideration, by which the last remaining straight strips of bark 

 are not removed sooner than during the third tapping period. 

 If in reviewing the value of the various tapping methods, we also 

 consider the demands made in practice, namely, that the latex 

 should run easily and be easy to collect, and the incisions easy to- 

 make, and that the flow of latex from the wound should have 

 full play, we have no difficulty in giving preference to the herring- 

 bone incision, as long as it embraces only a small part of the tree's 

 circumference. If the incision be extended over half the tree's, 

 circumference, too long a time would have to elapse after the end 

 of the first tapping period, before it would be possible to begin 

 with the second. If it be extended over a third of the circum- 

 ference, the. series of incisions would, during the second tapping, 

 hinder on one side the side-flow of organic food material towards 

 the cortical tissues, which have been renewed beneath the incisions- 

 made in the first tapping period. Everything, therefore, points 

 to the following: to extend the tapping system only over a 

 quarter of the tree's circumference, to tap a second quarter in 

 the second, and the remaining quarters in the third ami fourth 

 tapping periods. 



We have still to consider whether preference should be gi\ en 



