se, the purchaser
cannot tell how many generations it is removed from the natural spawn.
For this quality of the spawn one must depend upon the knowledge which
we may have of the methods practiced by the different producers of
spawn, if it is possible even to determine this.

SPAWNING THE BEDS.

The beds for growing the mushrooms having been made up, the spawn having
been selected, the beds are ready for planting whenever the temperature
has been sufficiently reduced and the material is properly cured. It is
quite easy to determine the temperature of the beds, but it is a more
difficult problem for the inexperienced to determine the best stage in
the curing of the material for the reception of the spawn. Some growers
rely more on the state of curing of the manure than they do upon the
temperature. They would prefer to spawn it at quite a low temperature,
rather than to spawn at what is usually considered an optimum
temperature, if the material is not properly cured. The temperature at
which different treatises and growers recommend that the bed should be
spawned varies from 70 deg. to 90 deg. F. Ninety degrees F. is considered
by many rather high, while 70 deg. F. is considered by others to be rather
low; 80 deg. to 85 deg. is considered by many to be the most favorable
temperature, provided of course the other conditions of the bed are
congenial. But some, so far as temperature is concerned, would prefer to
spawn the bed at 75 deg. F. rather than at 90 deg., while many recommend
spawning at 70 deg. to 75 deg. In some cases, I have known the growers
to allow the temperature of the beds to fall as low as 60 deg. before
spawning, because the material was not, until that time, at the proper
state of curing. Yet an experienced grower, who understands the kind of
spawn to plant in such a bed, can allow the temperature to go down to 60
deg. without any very great risk. Fresh spawn in an active state, that
is, spawn which is in a growing condition, as may be obtained by tearing
up a bed, or a portion of one, through which the spawn has run, is
better to plant in a bed of such low temperature. Or, a bed of such low
temperature, after spawning, might be "warmed up," by piling fresh horse
manure over it loosely for a week or ten days, sufficient to raise the
temperature to 80 deg. or 90 deg.

[Illustration: FIGURE 235.--Pieces of brick spawn ready to plant.]

When the brick spawn is used, the method of planting varies, of co