

THE RED ROT OF CONIFERS 17 



first and has the appearance of being covered with velvet. The radial 

 growth of the hyphae is rapid and a sheet is formed which adjusts 

 itself to the shape of the stub. At the edges this sheet projects from 

 the bark and forms an irregular shelf, the top of which after a time 

 becomes brown and hairy and ultimately develops into a bracket for- 

 mation. The growth seems to take place most rapidly through 

 the latter part of the summer and the early fall. The hyphae at the edge 

 of the sheet extend their area, while those forming the walls of the 

 pores grow vertically downward. It is not known to what age one of 

 these sporophores may attain. 



Most writers call attention to the fact that fruiting bodies are 

 common only on the larger and older trees. While this is true to a cer- 

 tain degree, the production of sporophores by no means is confined 

 to such trees. The writer found that they were as common on diseased 

 trees less than seven inches in diameter as they were on larger and older 

 trees. One good specimen was found on a pine about six inches in dia- 

 meter and only about 30 years old. The entire surrounding stand in this 

 case was only from 45 to 50 years old and fully as large a percentage 

 of diseased trees was detected here as in any stand examined. 



These fruiting organs exist on both standing and fallen trees. Von 

 Schrenk says : "They were found on trees which had been cut down 

 four years before and new ones were constantly appearing." In view 

 of the fact that the mycelium practically ceases growth as soon as the 

 wood is placed in a position where desiccation will take place, it would 

 seem that such sporophores could not be kept in a condition to function 

 for any length of time after the fall of the tree, unless the tree fell 

 in a position to cause the excessive absorption of moisture. However, 

 it is this faculty of -fruiting to a greater or less extent on dead trees 

 which must enable this fungus to accomplish its rapid spread. 



IX. PREVENTIVE MEASURES 



The discovery of this disease and of its method of spread in Ger- 

 many immediately led to search for some means by which its ravages 

 could be controlled. Most students of this malady as it occurs in 

 Europe have suggested the following procedure: 



1. Prevention of branch breaking. Laws have been enacted to 

 prevent wood gatherers from breaking off branches which leave an 

 open wound in the heart-wood, thus encouraging the entrance of the 

 fungus. These wood gatherers damage forests which lie near cities 

 and villages. They are supposed to take only the dry dead branches, 



