CULTIVATION OF MUSHROOMS. 243 



each with its independent ridge roof and system of ventilation. The 

 separating walls between the several houses of such a block are 

 probably maintained for the purpose of better controlling the tem- 

 perature conditions and ventilation in various houses. If desired, 

 cummunication from one house to another can be had by doors. 



Interior structure and position of the beds. The beds are usually 

 arranged in tiers, one above the other, though in some houses the 

 beds are confined only to the floor space. Where they are arranged 

 in tiers in a house of the proportions given above, there are three 

 tiers of beds. There is one tier on either side, and a tier through the 



Figure 228. View in mushroom house (Wm. Swayne), showing upper bed in left 

 hand tier. Copyright. 



middle ; the middle tier, on account of the peak of the roof at this 

 point, has one more bed than the tiers on the side. The number of 

 beds in a tier will depend on the height of the house. Usually the 

 house is constructed of a height which permits three beds in the side 

 tier and four in the center tier, with an alley on either side of the 

 center tier of beds, giving communication to all. If the house is 

 very long and it is desirable, for convenience in passing from one 

 house to another, to have cross alley-ways, they can be arranged, 

 but the fewer cross alleys the larger surface area there is for beds. 

 The size of the beds is governed by convenience in making the 

 beds and handling the crop. The beds on the side tiers, therefore, 

 are often three to three and one-half feet in width, affording a con- 



