e bringing the mushrooms up out of the caves they are
covered over with a cloth to avoid contact with the outer air, which is
apt to turn them brown. They are then placed in baskets that contain
twenty-three to twenty-five pounds and sent to market, where they are
sold at auction as they arrive. Or they may be sent to
preserved-vegetable manufacturers, who contract for them at an all round
price.

[Illustration: FIG. 29. GATHERING MUSHROOMS IN THE PARIS CAVES FOR
MARKET.]

Proper ventilation is regarded as being of great importance, not only
for the sake of the workmen, but also for the mushrooms, which will not
thrive in an impure atmosphere. Ventilation is afforded by means of
narrow shafts surmounted by tall wooden chimneys whose upper ends are
cut at an angle so that the beveled side faces north. In order to avoid
sudden changes of temperature and strong draughts, fires, trap doors,
and other means employed in assisting the ventilation of coal mines
are adopted. To stop strong draughts, too, in the passages, tall,
straw-thatched hurdles are set up. In narrow caves the breath of the
workmen, the gases given off by fermentation, and the products of
combustion of the lamps would soon so vitiate the atmosphere as to
render the caves uninhabitable were they not properly ventilated.
Indeed, it frequently occurs that caves in which mushrooms have been
grown continuously for some years have to be abandoned for a year or two
because the crop has ceased to prosper in them. But after they have been
thoroughly cleared of all beds and the surface soil that would have been
likely to be touched or affected by the manure, and ventilated and
rested for a year or two, mushrooms can again be grown in them
successfully.

CHAPTER XXII.

COOKING MUSHROOMS.

Fresh mushrooms, well cooked and well served, are one of the most
delicious of all vegetables. If we grow our own mushrooms we can gather
them in their finest form, cook them as we please, and enjoy them in
their most delightful condition. If we are dependent upon the fields we
should be careful to gather only such mushrooms as are young, plump, and
fresh, and reject all that are old or discolored, or betray any signs of
the presence of disease or insects. And in the case of store mushrooms,
that is, the ones we get at the fruiterer's or other provision store, we
should examine them critically before using them to see that they are
perfectly free from "flock," "black sp