MUSHROOM GROWING. 39 



If the spawn grows rapidly at first and spreads throughout the bed, 

 it will not be injured by a slight drying out, or by a tenij^erature even 

 as low as ?>'2° F. On the other hand, a continuous high temperature 

 for several days, or excessive watering, is sure to result in an irrep- 

 arable injury. In several instances where the experimental beds of 

 the writer have been made during the late autumn, and Avhere a 

 ^'igorous growth of spawn has been secured before the advent of the 

 coldest weather, the beds have remained unproductive throughout the 

 winter months, or so long as the temperature remained intermittently 

 below 40° or 50° F. With warmer weather, these beds have come 

 into bearing several months later, and where the temperature has then 

 remained favorable for some time a good yield has l^een obtained. In 

 this case, moreover, the ])ed will bear much longer at a temperature 

 of 60° F., or above, than if the temperature has been constantly in the 

 neighborhood of 60° F. throughout the growing season of the si:)awn. 

 As a rule, beds thus filled with spawn and then subjected for a time 

 to cold conditions yield at the outset much larger mushrooms than 

 beds exposed to a more constant temperature, even if this constant 

 temperature may be the optimum. 



At any rate, the beds nuist be " cased ■' as soon as convenient after 

 the spawn is inserted. As a rule, one should wait from one to two 

 weeks in order to be sure that the spawn is growing. Casing consists 

 m applying to the bed a layer of loam from 1 to U inches deep. In 

 France the casing soil consists usually of calcareous earth, sometimes 

 mixed with loam. Ordinary loam of almost any quality will suffice. 

 This should l^e secured in advance, and it is well to protect it from the 

 Aveather, so that at a convenient time it may be worked over and, if 

 necessary, screened, in order to free it from large pebbles or trash. 

 When the loam is applied, it should, on ridge beds, be carefully 

 firmed. AMien cased a bed should require watering for the most part 

 merely to maintain a moist surface. 



MUSHROOM GROWING. 

 EXPERIMENTS AT COLUMBIA, MO. 



The practical experiments in mushroom growing which have been 

 undertaken at Co'lumbia, Mo., were designed, in the first place, to 

 determine the exact ertect of conditions upon the growth of mush- 

 rooms, and in the second place to test or immediately ai)ply the 

 results obtained or suggested by the laboratory work. The etfects 

 of temperature, moisture, etc., have already l)een discussed, and the 

 conclusions drawn have l)een based ui)on the most careful ()l)serva- 

 tions of the experimental beds, as well as upon the evidence which 

 has been obtained In* a personal study of the conditions in commer- 

 cial mushroom houses and caves both at home and aI)road. It is 

 needless to give in detail the record of all failures or of poor yields 



