yield, which after all, by reason of injury accruing to the tree, 

 may only be of short duration. 



Judging from the results of my experiments, I feel bound, in 

 the case of young trees, to warn planters against the use of all those 

 tapping cuts by which the rectilinear connection of the vertical 

 channels for the circulation of organic substances in the cortex and 

 bast suffer a complete, or almost complete, interruption at any spot 

 between the crown and the base of the tree. I would also advise 

 them to abstain from all these methods, at least while we are quite 

 in the dark with regard to the length of time required after the 

 conclusion of the tapping period for the refilling of the reservoirs 

 in the stem below the tapping spot. But even after this point has 

 been cleared up, all those tapping cuts will always be preferable 

 which do not, even temporarily, subject the trees to any extensive 

 injury. 



Therefore, in the case of young plantations, the first system 

 to be rejected is the spiral one. 10 Just as impracticable are all 

 other methods which adopt the same principle as the spiral 

 incision : V-cuts, which leave no rectilinear strips of bark of 

 any great size on the tree, the double herring-bone incisions, that 

 cover the whole of the tree's circumference, two half herring-bone 

 incisions, each of which extends over half the tree's circum- 

 ference. Furthermore, I consider all those tapping methods 

 unsuitable, by means of which straight strips of bark are jat 

 first left between the incisions, which are, however, in the second 

 tapping period, following on the first one, completely removed 

 by a new system of incisions. It is on the contrary, absolutely 

 necessary, by means of old, uninjured bark, or at least by bark 

 that has not been tapped for a long time, to keep up a sufficiently 

 broad rectilinear connection between the crown and the base of 

 the tree, until the necessary number of new channels has been 

 formed in all parts of the bark which is being renewed on the 

 tapping spots, including therefore that beneath the very last 

 tapping incision; until it can be proved, that the new bark has 



10 It is a matter of indifference, whether in adopting the spiral 

 cut, the bark of the tree is removed rapidly or slowly. The spiral curve 

 is not to be rejected, because by this method a ,^re .it t|uantity of bark- 

 is in course of time removed from the tree, but because it completely 

 destroys the food-channels. It set-ins to me necessary to lav stress on 

 this fact, because several competent authorities still seem undecided on this 

 point. Compare for instance, H. Wright, " I levea Hrasiliensis," | .ondon, ed. ;, 

 iooH. Pages 94 and 132. 



