18 BULLETIN 871, TJ. S. DEPARTMENT OF AGRICULTURE. 



extended to 29.4 feet, and then the typical pockets of dry-rot reap- 

 peared, which ultimately ended at a height of 41.4 feet. The only 

 possible means of entrance for the two forms of decay were the small 

 open fire scars at the ground level. A similar condition is presented 

 in tree No. 7 on the intermediate area. This tree had a large open 

 fire scar extending from the ground level to a height of 8 feet. Typical 

 dry-rot entering through this open wound began at 6 feet, extending 

 to 9.7 feet, where it merged into Trametes pini decay, which then gave 

 place to the typical dry-rot at 14.7 feet, and the latter finally ended 

 at a height of 20.7 feet. No line of demarcation could be distinguished 

 between the two decays, and the point of entrance of the infection was 

 at the open fire scar. Other examples could be cited, but these seem 

 sufficient. 



In the eleven trees in which the dry-rot in small pockets occurred 

 it was either very close to or intermingled with typical dry-rot in six, 

 and in four of these six trees both forms of decay could be exactly 

 traced to a common point of entrance. There were no apparent lines 

 of demarcation in any instance between the two forms of decay. In 

 tree No. 392 in the intermediate range typical pockets of dry-rot 

 extended from ground level to 28.7 feet. At this point the typical 

 decay changed to the small pockets, and this form occupied the 

 heartwood to 36.9 feet, where the decay stopped altogether. 



Finally let us consider the eight trees in which both the dry-rot in 

 small pockets and the Trametes pini decay were found. In two of 

 the trees the two decays occurred in different parts of the bole. In 

 two trees the decays were very close together, while in four trees the 

 two were accompanied by pockets of typical dry-rot. Tree No. 296 

 on the intermediate area offers an excellent illustration of this last 

 condition. In this tree the dry-rot in small pockets, the Trametes pini 

 decay, and typical pockets of dry-rot were intermingled, and transi- 

 tion stages between the three forms were apparent from ground level 

 to a height of 30.3 feet. In four of" the eight infected trees it was 

 possible to trace the entrance of both decays to the same point, 

 healed fire scars. There were no lines of demarcation separating the 

 various decays. 



The interesting point in connection with the two forms of dry-rot 

 and the decay caused by Trametes pini is that they occurred in the 

 same substrata, either merging into one another or actually inter- 

 mingling without any well-defined lines between them. That such 

 lines of demarcation between different decays are the general rule 

 has long been accepted and has been most recently expressed again 

 by Weir (31). Hence, it is particularly interesting to find two 

 exactly opposite tj^pes of decay intermingling so freely. It is quite 

 probable, however, that such occurrences in the future will come to 

 be recognized as quite common. The writer has already found 





