NUTRITION 



of the mycelium to grow even when the ma- 

 nure is in such small quantity that noticeable 

 temperature increase does not occur. Fer- 

 mentation acts generally, therefore, not by 

 improving the quality of the manure, but 

 by effecting a complete change in the bac- 

 terial activity. 



The effect of the fermentation serves ap- 

 parently, to remove or transform rapidly 

 fermentable products. Again, it induces 

 certain changes in the insoluble material 

 and straw whereby the mushroom mycelium 

 is then able to grow slowly and to compete 

 with the micro-organisms next involved. 

 The nutrients used by the mushroom are, of 

 course, both the gradually soluble organic 

 products as well as the necessary inorganic 

 salts. The once prevalent belief that the 

 ^'ammonia" of the manure might constitute 

 the only important fertilizer in mushroom 

 culture is certainly erroneous; but manure 

 so treated as to effect the loss of much free 

 ammonia is injured for manurial purposes. 



Growth on ^^synthetic'^ media. The my- 



i9 



