ROT-FUNGI AND THEIR WORK 77 



retting owners of chestnut timber as to the way 

 to handle and use affected trees. There is no 

 wholesale method of combating the disease. 



Valuable trees can, however, be treated indi- 

 vidually. In an interesting article in the Febru- 

 ary, 1 9 13, American City Mr. R. G. Pierce de- 

 scribes his system of treatment. 



" All the diseased bark or wood must be re- 

 moved from the tree and burned. The tools, 

 such as gouge, chisel, knife or hand ax, used in 

 this cutting-out work, as well as the cut surface, 

 should be thoroughly sterilized. The wound 

 after sterilization should be covered with some 

 water-proofing. . . ." Mr. Pierce goes on to de- 

 scribe his method of operating in detail. Small 

 branches which are affected he removes with a 

 sterilized saw. Diseased areas on larger limbs 

 he cuts out, cutting into the wood a depth of five 

 or six an^nual rings, and removing at least an 

 Inch of healthy bark around the discolored area. 

 Tools must be sterilized (as by dipping in creo- 

 sote) before the final layer of wood is removed. 

 Mr. Pierce catches the diseased bark thus gouged 

 out In a bag to prevent it from infecting lower 

 branches in its fall. 



The fungi of the next group, those causing 

 decay of the sapwood, are probably in no case 

 true parasites. When they attack living trees it 

 is only very weak trees which are seriously dam- 



