182 THE FORCING GARDEN. 
Mushroom houses at the back of hothouses in locali- 
ties infested by this pest will always prove futile for 
complete success, unless some additional provision is 
made to keep off these marauders. It is much better 
in such localities to go to the expense of building a 
Mushroom house quite independent and detached from 
all other buildings, so that in extreme cases there may 
be no harbour to encourage these pests more than can 
be well avoided. They will, I know, find their way if 
possible, to any rendezvous where they can get the 
warmth, seclusion, and food that they like; but they 
are rather careful not to expose themselves too much, 
lest they may get picked up by an enemy and be eaten. 
And here let me give a little of what I think timely 
and valuable advice. In such localities as I refer to 
where the woodlouse naturally abounds, let intending 
Mushroom growers get as many hedgehogs and guinea 
pigs as they can and keep them about the place. 
Hedgehogs! say some: how are you going to keep 
hedgehogs? Why, keep them in the Mushroom house, 
to be sure, where they will destroy every beetle and 
woodlouse, and the guinea pigs will do the same work 
outside. 
The Mushroom house should be so constructed as 
to prevent the intrusion of the woodlouse. In the 
first place the outside walls must be proof against the 
ingress of all such pests ; and secondly, no beds should 
be made on the immediate ground floor, but should be 
raised about a foot, so that a trough of water may run 
round the floor, as seen in the above plan; this will 
prevent them from climbing the walls and the stays of 
the beds above. The woodlouse will not enter water. 
The troughs of water will give off a congenial vapour 
