"Nnw York Agricultural Experiment Station. 273 



about half or two-thirds of the way up to the branches, and a few 

 very short clefts or perhaps wind-checks were scattered over the 

 base of the south side. About three-fourths of the loosened bark was 

 partly alive, and in some spots more or less regeneration had occurred 

 on the wood surface under it. At the right of figure A on Plate XV 

 some such spots are readily seen as darkened areas. Most of the 

 bark on the northwest side, including the piece hanging by its upper 

 end, was dead and the wood surface underneath had a dark brown 

 color. The loose bark taken from B had been cleft at a few places 

 near the ground, but none of the clefts reached more than a fourth 

 of the way up the trunk. All of the bark except that surrounding 

 the clefts still appeared normal externally but on removal was found 

 to have a rusty or dark brown color on its inner side. Between 

 the closely appressed bark and the wood was some disorganized and 

 discolored slime. The loose bark was not uniform throughout; 

 there were often large areas in which it was dead and discolored only 

 to the outer layers of cortex, while in others even the whole of the 

 cortex had died in small spots. It seemed evident that the entire 

 loosened portion of bark was dying from within outward. 



For trees of that age this is an unusually high percentage of injured 

 ones. Over 46 per ct. of them were more or less severely affected 

 and over 15 per ct. were completely girdled or fatally injured. Yet, 

 when the orchard was first seen the foliage of all trees appeared of 

 the same normal color, although after the loosened bark had been 

 removed one could readily imagine that the leaves of most of the 

 girdled trees were of a yellowish or lighter shade of green than the 

 others. That seemed most noticeable on trees like that in figure B 

 on Plate XV, which had much discoloration of the wood. 



Several of the less severely affected trees also had injured bark in 

 their lower crotches. In some cases the injured bark looked dis- 

 colored or dead while in others it still appeared normal externally 

 although on removal was found to be partially separated from the 

 wood and to have a rusty to bro^vn dark phloem. In other instances 

 small clefts or wind-checks were present in the dead bark, but most 

 frequently it was uncleft. When patches of injured bark had com- 

 pletely died they looked like typical crotch cankers. The dead 

 areas were sunken below the level of the normal bark and were 

 unusually delimited by a more or less conspicuous line of fissure. 

 In cases where the cortical portion of the affected bark was yet 

 mostly alive the fissure was less conspicuous or even entirely absent, 

 but on cutting out a piece across the indefinite region of transition 

 from the injured to the normal bark the cause and location of the 

 cleavage became apparent. A definite but thin ridge of callus was 

 found running around the periphery of the injured areas, indicating 

 that the cause of the fissure is the increase in thickness under the 

 normal bark and its absence of thickening, combined with the dryiug 

 out and dying of the bark, over the several affected areas. 



