MUSHROOM GROWING 



Specimens produced when the spawn is just 

 beginning to ''run" (therefore not so vigor- 

 ous) may be more like the typical form; and 

 those produced at the end of the season may 

 again seem more typical. It is obviously 

 necessary to follow carefully the effects of 

 conditions and vigor of mycelium on the 

 general appearance of the plant. I have 

 found that A, campestris grown on com- 

 posted leaves exhibits very little pink in the 

 gills, and the color changes rapidly from 

 pale brown to a gray-brown. Color of the 

 cap is subject to more or less change, and ex- 

 periments have clearly shown that exposure, 

 including the action of light and wind, in- 

 tensify the color up to a certain point. 

 Forms which produce perfectly white mush- 

 rooms in moist places, especially when pro- 

 tected by an inverted flower pot, may pro- 

 duce in the open, or near the door of the 

 mushroom house, plants which would not 

 be recognized as being the same species or 

 variety. 



Agaricus arvensis, formerly more com- 



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