296 STRUCTURE AND LIFE HISTORIES 



dollars. The mycelium of the fungus that causes it 

 (Endothia parasitica) grows underneath the bark, and 

 for this reason it is practically impossible to check it 



FIG. 218. Chestnut blight. Portion of a branch of an American chest- 

 nut (Castanea dentata), which had been artificially inoculated with the 

 spores of the chestnut-blight fungus, Endothia parasitica (Murr.) Anders. 

 The white areas are infected spots. (After W. A. Murrill.) 



by spraying, as the bark protects the mycelium from all 

 known spraying solutions. The fruiting pustules of the 

 fungus form on the surface (Figs. 218 and 219). The 



