MUSHROOM GROWING 



distinguish the different species on struc- 

 tural grounds, a classification based on color 

 might be at least temporarily serviceable. 

 Accordingly it was recommended that for 

 trade purposes the smaller, practically pure 

 white form, in cultivation be called 

 ^'Alaska," the large cream colored form 

 (sometimes grayish) be called ^'Columbia" 

 (Plate I, a), and that the typical brown 

 variety of the English brick spawn be called 

 ^^Bohemia" (Plate V, a). This simple 

 classification has undoubtedly been of as- 

 sistance in directing the attention of grow- 

 ers to the necessity for distinguishing be- 

 tween varieties. The classification is, how- 

 ever, no longer adequate, and there is at 

 the present time great need for a careful 

 study of varieties and species. 



For a comprehensive study of this nature 

 a thorough knowledge of European forms 

 as well as of those found in America would 

 be essential. Moreover, it could not very 

 well be attempted unless the various forms 

 were grown at the same time under similar 



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