18 PRINCIPLES AND PRACTICE OF PRUNING 



The reasons for the peeUng practice are that timber merchants 

 behevc timber so peeled keeps in better condition than when peeled 

 after felling. It costs much more to peel the trees standing than 

 felled. Peeling begins as soon as the sap begins to rise, and is 

 continued till the trees come into leaf, when the bark cannot be de- 

 tached. Many of the trees are completely stripped of their bark 

 from bottom to top, except the topmost branches, yet large un- 

 barked tops continue to swell their buds and come into full leaf, 

 while the peeled trunks up to the heads are barkless and apparently 

 as dry as a board for perhaps 30 to 40 feet below. On some of the 

 trees the leaves fade before the summer is over, but on others they 

 continue till the end of the season. 



Cases similar to these came under the writer's observation at the 

 close of the Spanish-American war, when 450 U. S. army mules 

 were turned loose at Washington on the "Potomac Flats," where 

 they stripped the bark as high as they could reach from about 100 

 Carolina poplars. The trees continued green till the close of the 

 season, but, with a few notable exceptions, failed to leaf out the 

 following spring. These exceptions all had retained strips of un- 

 injured bark from base to branches in positions beyond the reach 

 of the mules so that food elaborated by the leaves could return to 

 the roots and thus maintain the life of the trees. 



In the orchard of the author's boyhood an Onondaga pear tree 

 through some accident became "barked" from the ground to the 

 first branches and for fully three-fourths of its girth, j'et it bore 

 excellent fruit for many years thereafter. 



22. The reason why. — In commenting on such cases as these A. C. 

 Forbes in a later issue of the Gardeners' Clironicle says in sub- 

 stance : The partial development of the annual shoots in trees de- 

 prived of their bark is only one of several interesting facts to be 

 seen in trees in a more or less unnatural condition. The growth of 

 the shoots on the barked trees is in no way more remarkable than 

 it would be had the bark remained on. 



The generally accepted view of tree growth is that the watery 

 sap rises through the outer rings of the stem into the leaves, there 

 Ijecomes greatly changed, and passes from the leaves through special 

 vessels in the bast or inner bark downward to the cambium and 

 other growing and storage tissues. The removal of the bark, there- 

 fore, if not carried too far, does not interfere directly with the 

 growth and support of the leaves but prevents the food which they 

 prepare being put to its proper use by the destruction of the down- 

 \vard conducting channels and the cambium layer. The continuation 

 of growth in the annual shoots under such circumstances depends 

 u(i(in the capability of the stem to retain its water-conducting power, 

 and the amount of reserve material contained in the roots, which are 

 thus enabled to carry on their absorptive functions. 



In the case of trees barked up to their smallest branches and 

 twigs, the water-conducting power of the upper parts of the stem 



