MARKET AND PRODUCTION 



Other plants — may be propagated, and the 

 spawn made from any particular variety de- 

 sired, as described in a later section. It is 

 certain that there exist many varieties, or 

 forms, of Agaricus campestris and related 

 species, but up to the present we cannot say 

 that there has been any general improve- 

 ment of any form for cultural purposes. 



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