y of the
"pinheads" will be injured and cause "fogging off."

But we can firm the dressing to the bed by watering it, which may be
done over the whole surface of the bed, and without sparing the
mushrooms, large or small. Use clear water and apply it gently through a
water-pot rose. I always do this, and have never known it to injure the
young mushrooms.

In the case of mushroom beds in which black spot has appeared in the
crop, I have found that a topdressing of fine, fresh earth applied
evenly all over the bed acts, to a certain extent, as a preventive of
further attack, but of course has no effect upon any of the already
affected mushrooms, large or small.

CHAPTER XV.

THE PROPER TEMPERATURE.

The best temperature at which to keep the mushroom house or cellar is
55 deg. to 57 deg.. But much depends upon the method of growing the esculent;
the construction of the house or cellar, and other circumstances.
Mushrooms can be successfully grown in buildings in which the
temperature may be as low as 20 deg. or as high as 65 deg.. By covering the beds
well with hay or other protecting material they can be kept warm, even
in sharp frosty weather, as the London market gardeners do with their
outdoor beds in winter; but when the temperature in the structure in
which the mushrooms are grown averages as high as 70 deg. we can not hope
for success; indeed, 65 deg. is too high.

A high temperature in a close house or cellar is injurious; it hurries
in the crop and forces up the mushrooms weak and thin-fleshed and with
ungainly, long stems; it soon exhausts the bed. The time when its evil
effects are least visible is early in the fall and late in spring when
the outside temperature is high, and when the beds are in somewhat airy
rather than close quarters. In the Dosoris cellars there is a steady
difference of about 5 deg. in the temperature between the end next the
boiler, which is kept at 60 deg. precisely, and that of the farther end,
which registers 55 deg. steadily. There is very little difference in the
weight of crop produced on the beds at either end of these cellars, but
what little there is is in favor of the cooler end. At 60 deg. the crop
begins to come in in six to seven weeks after spawning, lasts for three
to four weeks in heavy bearing and a week or more longer in light
bearing, and then it gradually dwindles.

In a temperature of 55 deg. it may be seven weeks after spawning before the
mushrooms app