PREPARATION OF THE COMPOST. 33 



is believed to he essential. It is certain that in ]j()orly ventilated 

 caves nuishrooms do not sncceed. On the other hand, in a dry 

 atmosphere, oi- exposed to drying winds, mushroom beds soon cease 

 to bear, while such sporophores as are developing may have their 

 caps cracked and torn. 



jNIushrooms are grown in cellars, caves, or specially constructed 

 houses largely on account of the fact that temperature and moisture 

 are then practically under control. The nature of the structure or 

 cellar Avhicli is constructed for mushroom grooving must be deter- 

 mined, therefore, not merely by its expense, but by the etfectiveness 

 of the structure in regulating the factors indicated under the par- 

 ticular climatic conditions. 



It is not possible at this time to discuss cellar or house construc- 

 tion, and the accompanying illustration of nnishroom houses (Plate 

 VI, fig. 1) must suffice to give an idea of the types which are in use, 



PREPARATION OF THE COMPOST. 



It is not to be understood that there is one and only one method of 

 preparing compost for nnishroom growing. Nor is it always neces- 

 sary that the compost shall be in one particular stage of fermenta- 

 tion or deca3\ In fact, every change of condition elsewhere may 

 necessitate a similar change in the amount of fermentation wdiich 

 may,^ be most desirable. At the outset it should be understood that 

 it is not the '' fermentation " which is absolutely essential." The 



o Kepin, 1. e. (See translation in The Garden (London). February 5. 1898. 

 Special repi-int. pp. 10-lH.) Here it is stated that "manure is rendered capa- 

 ble of supplying nutriment suitable for nuishrooms only by means of fermenta- 

 tion ; " further, that " all the higher orders of nuishrooms, the spores of which 

 I have succeeded in causing to germinate. Jiave a sterile spawn of a similar 

 natui-e." Again, the conelusion is expressed somewhat indefinitely that manure 

 is '■ rendered suitable " by means of c-hemical conibustion, which is said to 

 proceed rapidly only at a temperature above 178° F. : that it is not the soluble 

 substances in the manure which are valuable, but rather the cellulose matter, 

 together with the necessary salts. 



In this connection it is of Interest to note that the material constituting many 

 of the beds in the experimental cellar at Columbia. INIo.. were fermented at 

 comparatively low temperatures. A complete temperature record was kept of 

 IS small compost piles in which special kinds of manure were i)repared, 

 and in only one instance was the temperature in any pile more than 140° F. 

 In some cases 120° F. was the maximum attained. 



Repin imjdies that mushrooms will not grow in maiiui'c until there lias i)eeu 

 effected " the destruction of all the soluble organic matters, which disappear 

 through the agency of bacteria or are consumed in the process of oxidation." 

 \'ery simple nutrition exi)eriments clearly demonstrate that these conclusions 

 are erroneous. 



It may be stated, however, that peculiarities appear when the fresh manure 

 contains certain comi)ounds which render it injurious; for example, the my- 

 celium does not grow readily in pure culture ui)on fresh manure from animals 

 fed almost wholly on green forage. Sucli manure is improved by fermentation. 



