MUSHROOMS 417 
case too soon is a disadvantage. During the intervals 
some sprinkling may be necessary to keep the beds moist. 
Moisture conditions.—Proper moisture conditions at 
all times after the beds have been started are of the 
greatest importance. Excessive humidity in the house 
should be avoided, but the atmosphere should be moist 
enough to prevent rapid evaporation from the surface of 
the beds. Molds and foreign fungi may develop if too 
high humidity is maintained. The best mushroom houses 
are provided with means of ventilation by which tempera- 
tures may be regulated and the humidity of the houses 
controlled to a great extent. 
Mushrooms require a certain amount of soil moisture, 
just as do the higher classes of plants. There is always 
some daily loss of moisture from the beds by evaporation, 
and the harvesting of a successful crop also removes a 
considerable quantity of water. Some of the old growers 
claimed that the beds should never be watered after the 
mushrooms began to appear, and no doubt this was often 
responsible for light crops. Drenching and over-water- 
ing should be carefully avoided, but there can be no 
doubt about the value or necessity of light sprinklings 
whenever the casing seems to indicate the need of such 
treatment. If the casing is kept moist, but not wet, there 
will be no danger of the compost or manure becoming 
too dry. Contrary to the best practice in vegetable forc- 
ing, it is desirable to water frequently but lightly, but 
application should never be made unless there is assur- 
ance that water is really needed. So much water should 
never be applied that it will penetrate the casing and run 
into the manure, for this invariably weakens the my- 
celium, especially in the early stages of growth. No rule 
can be given concerning the frequency of watering any 
more than for the watering of greenhouse crops. 
Temperature.—An atmospheric temperature of about 
55 degrees is considered as ideal for the growing of mush- 
