188 THE FORCING GARDEN. 
The Agaricus campestris will grow to an immense 
size under favourable conditions. I have gathered 
them as large as an ordinary dinner plate, at least nine 
inches in diameter, and so full of catsup that one pint 
has been made from one of them, and many a time 
they have been gathered as large as a small cheese 
plate. I merely note these things to show under what 
conditions the Mushroom will do best, and to modify 
the idea that they can be grown by very clever men 
only. In the plan at the head of this chapter I have 
no doubt that it will be seen that the water at the 
bottom of the beds is necessary everywhere in houses 
where heat is indispensable in order to obtain winter 
Mushrooms; and, as I have said before, in localities 
where the woodlouse and beetle abound, it will be a 
bar to their getting at the beds. It is necessary to 
thinly but securely cement the trough a little beyond 
the uprights of the beds, so that the feet of these posts 
are surrounded by water; or the beds may rest on 
brick pillars one foot high from the floor of the house. 
This house is on a scale of one-eighth of an inch to 
one foot. This gives four-feet pathways and eight-feet 
beds, which may be rather wide, but they should not 
be less than six feet wide; then there is more body in 
them, and they will not dry so soon. The beds should 
be not less than one foot thick, and should be well 
beaten together when made, with a mallet. The drop- 
pings from the stable may contain some short straw ; 
all should be well mixed and laid up in a heap to fer- 
ment a few days before making the beds, and some 
half-dry or old cow-dung may be mixed with the drop- 
pings when the beds are made. The earthing of them 
after they are made should be done immediately, and 
