1922] Essig: Morphology of Schizophyllum comrmine Fries 471 



7. ASSOCIATION WITH OTHER WOOD DECAY FUNGI 



Fulton (1912) found that in an apple collar rot which he described 

 Schizophyllum commune was present along with two other organisms. 



Stone (1910) found in sun scald and scorch of maples that it was 

 followed first by a canker fungus {Nectria cinnabarina) , and then by 

 Schizophyllum and Polystictus. 



In the ease of the apple graft mentioned above, the writer took 

 the branch, sawed it into sections, and placed some of the sections in 

 a moist chamber. From the decayed area a mass of mycelium appeared 

 which was not of Schizophyllum, but as it has not yet produced any 

 fruit bodies it cannot be identified. 



Observations show that the fruit bodies of Schizophyllum are pro- 

 duced in a comparatively short time after inoculation has taken place. 

 I have noted several times in the field that this fungus is the first to 

 appear upon uprooted trees. Later, sporophores of Polystictus, 

 Polyporus, Tremella, Hydnum, and other fungi are produced. Most 

 of the pieces of wood I have collected in the field, which have only 

 sporophores of Schizophyllum upon them, when placed in moist cham- 

 bers long enough will produce sporophores of Hydnum, or Polystictus, 

 or both, long after a great number of fresh Schizophyllum fruit bodies 

 have been formed. Since the hyphae of these other fungi were in 

 the wood along with that of Schizophyllum,, it is apparent that the 

 latter fungus develops sporophores in a much shorter time than the 

 others present. Schizophyllum, forming fruit bodies first upon a dis- 

 eased tree, is naturally accused of being the parasite causing the dam- 

 age. The writer believes that much or even most of the injury to trees 

 attributed to this fungus is actually caused by the fungi so often 

 associated with it, such as Polystictus versicolor, which is beyond doubt 

 a parasite.^ 



2 Proof of the parasitism of P. versicolor was given by W. W. Thomas in 1916 

 at the University of California in a thesis submitted for -a. Master's degree. 

 Mr. Thomas inoculated living trees with positive results as regards infection. 



