CULTIVATION OF MUSHROOMS. 263 



manure heaps. Beds made up in the ordinary way for the cultiva- 

 tion of mushrooms are planted with this. The mycelium is allowed 

 to run until it has thoroughly permeated the manure. These beds 

 are broken down and used to spawn the beds for the crop. In this 

 case the crop would be grown from spawn only one generation re- 

 moved from the virgin spawn. If a sufficient amount of natural 

 spawn could not be obtained, to provide the amount required one 

 generation old, it might be run through the second generation be- 

 fore being used. From the appearance of any spawn, of course, the 

 purchaser cannot tell how many generations it is removed from the 

 natural spawn. For this quality of the spawn one must depend 

 upon the knowledge which we may have of the methods practiced 

 by the different producers of spawn, if it is possible even to deter- 

 mine this. 



SPAWNING THE BEDS. 



The beds for growing the mushrooms having been made up, the 

 spawn having been selected, the beds are ready for planting when- 

 ever the temperature has been sufficiently reduced and the material 

 is properly cured. It is quite easy to determine the temperature of 

 the beds, but it is a more difficult problem for the inexperienced to 

 determine the best stage in the curing of the material for the recep- 

 tion of the spawn. Some growers rely more on the state of curing 

 of the manure than they do upon the temperature. They would 

 prefer to spawn it at quite a low temperature, rather than to spawn 

 at what is usually considered an optimum temperature, if the ma- 

 terial is not properly cured. The temperature at which different 

 treatises and growers recommend that the bed should be spawned 

 varies from 70 to 90 F. Ninety degrees F. is considered by many 

 rather high, while 70 F. is considered by others to be rather low ; 

 80 to 85 is considered by many to be the most favorable temper- 

 ature, provided of course the other conditions of the bed are con- 

 genial. But some, so far as temperature is concerned, would prefer 

 to spawn the bed at 75 F. rather than at 90, while many recom- 

 mend spawning at 70 to 75. In some cases, I have known the 

 growers to allow the temperature of the beds to fall as low as 60 

 before spawning, because the material was not, until that time, at 

 the proper state of curing. Yet an experienced grower, who under- 

 stands the kind of spawn to plant in such a bed, can allow the tem- 

 perature to go down to 60 without any very great risk. Fresh 

 spawn in an active state, that is, spawn which is in a growing con- 

 dition, as may be obtained by tearing up a bed, or a portion of one, 



