MUSHROOM GROWING IN THE PARIS CATES. 147 
tion of the spawn and how well it has run in the manure. 
Before being earthed over the outside surface of the beds 
should be covered with white filaments radiating in all 
directions which give to the beds a bluish appearance. 
When the bed is in the proper state for being covered 
with earth the mold is laid on equally and firmly over 
the surface about three-fourths of an inch deep. It is 
then thoroughly watered through a fine-rosed watering pot 
and allowed to settle until the next day, when it is 
beaten solid by the back of a wooden shovel. The bed 
now needs no further care until the young mushrooms 
appear, except a light occasional watering should it 
get dry. 
In spacious, high-roofed caves the mean temperature 
is about 52° F., while in narrow, low-roofed ones it is 
Fig. 28 . In the Mushroom Caves of Paris. 
about 68°. Of course this makes a wide difference in 
the time of bearing and duration of the beds made in 
the different caves ; those in the warm caves come into 
bearing sooner and stop bearing quicker than do those 
in the high-roofed caves. On an average the first mush- 
