MUSHROOM GROWING 



this has consistently shown a high yield and 

 quality. It is likely that ''running out" 

 would be in part due to improper care of the 

 pure cultures. Analogous cases are well 

 known, as when continuous culture of cer- 

 tain pathogenic fungi in the laboratory suf- 

 fices to materially lower their pathogenicity. 

 Spore germination. Some will no doubt 

 wonder w^hy there should be any serious dif- 

 ficulty in germinating mushroom spores, 

 and in thus producing spawn by a direct 

 and natural process. The difliculty lies in 

 the fact that the spores do not germinate 

 readily, and such methods of stimulating 

 germination as have been made known are 

 far less easily applicable than the tissue cul- 

 ture method already described. Some years 

 ago Costantin and Matruchot reported that 

 they had been able to produce mushroom 

 spawn from spores. Their work was re- 

 ported in such manner that only the results, 

 and not the methods, were made known, and 

 it has remained a secret. Since they dis- 

 tinctly refer to the use of spores, it is to be as- 



104 



