in the quality and quantity of
the crop exceed those produced from the market spawn. But even these
growers would not always depend on the natural spawn, for the reason,
that collecting it under these conditions, the quantity is certain to
vary from year to year. This is due probably to varying conditions of
the season and also to the varying conditions which bring about the
chance inoculation, or the accumulation of the material in the yard for
a sufficient amount of time to provide the mycelium.

It would be interesting, and it might also prove to be profitable to
growers, if some attempt were made to grow natural spawn under
conditions which would perhaps more certainly produce a supply. This
might be attempted in several different ways. Stall-fed horses might be
fed a ripe mushroom every day or two. Or from the cap of ripe mushrooms
the spores might be caught, then mixed with oats and fed to the horse.
Again, the manure piles might be inoculated by spores caught from a
number of mushrooms. Manure might also be collected during the summer
months from the highways and aside from the probable natural inoculation
which this material would probably have from the spores blown from the
meadow and pasture mushrooms, additional inoculation might be made. The
manure obtained in this way could be piled under sheds, packed down
thoroughly, and not allowed to heat above 100 deg. F. These piles could
then be left for several months, care being used that the material should
have the proper moisture content, not too dry nor too wet. This is given
only as a suggestion and it is hoped that some practical grower will
test it upon a small scale. In all cases the temperature should be kept
low during the fermentation of these piles, else the spawn will be
killed.

One of the methods of obtaining natural spawn recommended by Cuthill
("Treatise on the Cultivation of the Mushroom") is to collect horse
droppings all along the highways during the summer, mixing it with some
road sand and piling it in a dry shed. Here it is packed down firmly to
prevent the heat rising too high. A "trial" stick is kept in the pile.
When this is pulled out, if it is so hot as to "burn the hand," the heat
is too great and would kill the spawn. In several months an abundance of
the spawn is generated here.

=Mill-track spawn.=--"Mill-track" spawn originated from the spawn found
in covered roadways at mills or along tram-car tracks where horses were
used. The