the shaft, are sifted, and the finer part
saved and mixed with earth in the proportion of three parts of stone
dust to one of earth, and with this the beds are molded over. The
powdered stone is strongly impregnated with salts, so advantageous to
the mushrooms.

In seven to nine days after spawning, the beds are ready for earthing
over. This depends upon the condition 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.

[Illustration: FIG. 28. IN THE MUSHROOM CAVES OF PARIS.]

In spacious, high-roofed caves the mean temperature is about 52 deg. F.,
while in narrow, low-roofed ones it is about 68 deg.. 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 mushrooms appear in about forty days after the beds
are spawned, and the beds continue bearing for forty or sixty days, but
toward the end of that time the yield diminishes very rapidly.

They are gathered once a day, usually about midnight, so that they may
reach the Paris market early in the morning. In size the mushrooms range
from three-fourths to one and five-eighths inches in diameter of top,
and are pure white in color. The workmen always gather the mushrooms by
plucking them out by the roots, and never by cutting them; the gatherers
have two baskets, carried knapsack fashion on their back; one is to
receive the mushrooms as they are picked, the other contains mold with
which to fill in the little holes made by pulling the mushrooms out of
the bed. In some caves one man gathers the mushrooms and leaves them in
little piles on the bed as he goes along, a woman comes after him and
places them in a basket, and a man follows her and fills up the holes
with earth. Befor