GROWING MUSHROOMS IN GREENHOUSES. 
53 
ordinary hotbed frames and sashes, as described in a 
previous chapter. Light wooden shutters—made of one- 
half inch or five-eighths inch pine—may be used for the 
same end, and will last for many years. 
The beds under the greenhouse benches may be made 
up in the same way as are beds anywhere else; that is. 
Fig. 17. Ridged Mushroom Bed. 
fiat upon the floor and between two boards set on edge, 
as seen in Fig. 16, or in ridges under the high or middle 
benches, as in Fig. 17, or in banked beds against the 
Fig. 18. Banked Bed against a Wall. 
back wall, as shown in Fig. 18. Generally the flat bed 
is the most convenient to make and take care of. 
In open, airy greenhouses it is always well to inclose 
the mushroom beds in box casings and with sash or shut- 
