MUSHROOM GROWING 



trariwise, the same treatment does not effect 

 the germination of the spores of Agaricus 

 campestris, or, at most, they only germinate 

 sporadically. Nevertheless, these spores 

 are capable of germination, and suitably 

 stimulated, a considerable percentage may 

 grow. Many attempts have been made by 

 practical growers to develop spawn from 

 spores, sowing the gill portions of mature 

 mushrooms in specially constructed beds; 

 but the results, so far as the writer is aware, 

 have not been satisfactory, and until recently, 

 growers had been compelled to rely upon 

 virgin spawn. After the tissue method 

 above described, the writer has grown thou- 

 sands of cultures, and there is no hesitation 

 in stating that it is entirely practicable as a 

 source of pure cultures for spawn-making. 

 Pure cultures and selection. The ad- 

 vantages of the pure culture methods are 

 obvious. Wherever the species may be 

 found or w^hatever it may be — provided the 

 specimens are growing vigorously, and free 

 from parasitic attacks — a culture may be 



102 



