MUSHROOM GROWING 



that while under the usual conditions, or 

 with the natural environment, the manure 

 must be fermented for mushroom culture; 

 yet chemically this fermentation is probably 

 more injurious than beneficial. Grown in 

 sterilized fresh manure in pure cultures the 

 mushroom mycelium grows as rapidly and 

 more profusely than in fermented manure 

 similarly treated. This indicates conclu- 

 sively that fermentation is not chemically 

 essential. It is essential for biological rea- 

 sons, which, briefly stated, are apparently 

 as foUovv^s : — Fresh manure contains some 

 very readily soluble and relatively unstable 

 organic products. These products are or- 

 dinarily the seat of pronounced and abun- 

 dant bacterial activity, perhaps also of some 

 important direct chemical rearrangements. 

 In the presence of rapid bacterial activity 

 (which occurs during this first stage of fer- 

 mentation) the mycelium of the mushroom 

 will not grow, — and that this is not due 

 merely to the usually accompanying in- 

 creased temperature is shown by the failure 



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