CHAPTER XV. 



THE PEOPEE TEMPEEATUBE. 



The best temperature at which to keep the mushroom 

 house or cellar is 55° to 57°. But much depends upon 

 the method of growing the esculent; the construction 

 of the house or cellar, and other circumstances. Mush- 

 rooms can be successfully grown in buildings in which 

 the temperature may be as low as 20° or as high as 65°. 

 By covering the beds well witli hay or other protecting 

 material they can be kept warm, even in sharp frosty 

 weather, as the London market gardeners do with their 

 outdoor beds in winter; but when the temperature in 

 the structure in which the mushrooms are grown aver- 

 ages as high as 70° we "can not hope for success; indeed, 

 65° is too high. 



A high temperature in a close house or cellar is injuri- 

 ous ; it hurries in the crop and forces up the mushrooms 

 weak and thin-fleshed and with ungainly, long stems ; 

 it soon exhausts the bed. The time when its evil effects 

 are least visible is early in the fall and late in spring 

 when the outside temperature is high, and wlien the 

 beds are in somewhat airy rather than close quarters. In 

 the Dosoris cellars there is a steady difference of about 

 5° in the temperature between the end next the boiler, 

 which is kept at 60° precisely, and that of the farther 

 end, which registers 55° steadily. There is very little 

 difference in the weight of crop produced on the beds at 

 either end of these cellars, but what little there is is in 

 favor of the cooler end. At 60° the crop begins to come 

 in in six to seyen weeks after spawning, lasts for three 



109 



