266 Repokt of the Botanical Department of the 



looked much like those shown on Plate IX with much of the regen- 

 eration left out. 



In some cases, however, considerable growth and regeneration had 

 occurred resulting in much unevenness in the bark; while in others 

 large areas of bark were only partially loosened, having no radial 

 clefts and still having a green color externally. Such loosened bark 

 had a rusty brown color with a sprinkhng of glistening white pin- 

 head-like specks on the side which had been in contact with the wood. 

 A closer study of the inner surfaces of such pieces of bark and of the 

 Vv'ood surfaces from which they were taken plainly showed that the 

 white specks of one corresponded exactly with those on the other. 

 It looked as though the bark had not been entirely separated from 

 the wood, but that here and there living groups of cells still main- 

 tained a connection between bark and wood. The injury and sepa- 

 ration had occurred in the phloem region. In very many other cases 

 carefully examined, such partially adhering areas of bark were nearly 

 dead throughout and there was considerable brownish slime between 

 the bark and wood with still an indication (at intervals) of glistening 

 white specks indicating a living connection at a few points. But 

 the wood had become discolored to the depth of 2 to 12 mm. under 

 such areas. 



In many instances, however, the whole of the bark had died, 

 become wind-checked and parts of it stood out from the smooth 

 wood surface. In general, on trees where the bark had been nearly 

 or entirely loosened it had apparently been dead for some time, and 

 there had been little or no staining of the wood beyond the outermost 

 1 to 3 mm.; while in the cases where the bark had been only partially 

 separated from the wood it was usually yet partially alive and the 

 wood underneath was stained more or less. 



The most remarkable feature about this case is the fact that 

 although receiving the same treatment in every way except in the 

 matter of pruning, there is such a great difference here between 

 the Ben Davis and the Baldwin varieties as regards their suscepti- 

 bility to the injury. In all the orchards studied before, these varie- 

 ties were not found so markedly different in their relative resistance, 

 while in this case the Ben Davis trees were wholly immune and the 

 Baldwins nearly all injured more or less. Since no difference could 

 be found in the environment or cultivation of the trees it seems 

 legitimate to infer that the above mentioned difference in the prun- 

 ing of the two varieties may have had some relation to the occur- 

 rence of the injury; that is, the high-headed trees were injured while 

 the low-headed ones remained normal. 



The Northern Spy, Wealthy and other varieties referred to above 

 had only a few trees among them slightly affected, and they were 

 mostly of the Wealthy variety. 



The fruit grower was advised to cut off, below the dead region, 

 all the trees which were entirely or almost entirely girdled and cover 



