necessary that the compost shall be in one particular stage of fer- 

 mentation or decay. In, fact, every change of condition elsewhere 

 may necessitate a similar change in the amount of fermentation 

 which may be most desirable. At the outset it should be under- 

 stood that it is not the "fermentation" that is absolutely essential. 

 The "fermentation" is of itself a minor matter. 



The rapid oxidation action of bacteria, and perhaps of inde- 

 pendent ferments, upon manure causes a considerable rise of tem- 

 perature, At the higher temperatures (which may be maintained 

 as long as there are present rapidly oxidizable food products) bac- 

 terial action is ■^'igorous, and is unquestionably injurious to mycelial 

 development. Wholly aside from the rise of temperatur.e accom- 

 panying their activities, bacteria are otherwise injurious. In fact, 

 manure which is put 'to test in a small test tube shows little or 

 no rise of temperature above that of the place iri^ which it is incu- 

 bated. Nevertheless, the mycelium of the mushroom will not grow 

 under such conditions. Rapid bacterial action is therefore preju- 

 dicial. Under those conditions where bacterial action is not rapid, 

 fresh manure might be used to advantage; in other words, if the 

 beds are so constructed that the manure ferments very gradually, 

 without either excessive bacterial action or rise of temperature, 

 then spawning might be made in fresh manure. 



The old belief that rotten manure does not have the necessary 

 strength — that is, does not produce so vigorous a mushroom growth 

 as that which has been less transformed by bacterial action — has 

 been confirmed by practical experiments. This loss of effectiveness 

 is probably due, in part, to a change in texture or to other physical 

 changes. In well-rotted manure there is ample food material to 

 support a- very good growth of mycelium in pure cultures. This 

 has been chemically proved by sterilizing such manure and growing 

 mushroom spawn upon it in pure culture. Nevertheless, beds 

 prepared with well-fermented manure and left for some time before 

 spawning do not yield so well. It is Relieved that here the physical 

 condition has much to do with the result. 



The latter does not by any means invalidate the following prac- 

 tice, which has cpmmended itself to some very successful growers. 

 The manure is piled in very large compost heaps, where it is kept 

 moist and is turned only once or twice. It ferments very slowly. 

 Then it is carted into the cave or mushroom house, long before it 

 could be considered in proper condition to be spawned. The beds 

 (usually flat when this is the prbdecure) are made immediately. 

 These are fairly well moistened and compressed, then left to under- 

 go a general fermentation, which, may require a month. When the 

 manure shows a tendency to fall to the temperature of the room 

 it, is spawned. Meanwhile, it will doubtless be found that a heavy 

 crop of some small species of Coprinus will have appeared. The 

 presence of this fungus is not injurious, but rather it may be taken 

 as an indication that the conditions are favorable. 



^Ordinarily the manure is obtained as fresh as possible. It should 

 include the straw used in bedding the animals, and the quantity 



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