from the pieces of spawn inserted next to this
one is affected by it; not even if the mycelium from the several lumps
of spawn forms an interlacing web. If the flock is confined to the
mushrooms produced from a certain bit of spawn some may ask, will the
other pieces of spawn broken from the same brick produce flock-infested
mushrooms? No. I have given this point particular attention, have kept
the pieces of each brick close together, and where flock has appeared I
have failed to find that the other pieces of spawn from that brick are
more liable to produce flock-infested mushrooms than are the pieces of
the bricks that, as yet, have not shown any sign of diseased produce.

How general is this disease? In a bed say three feet wide by thirty feet
long and of two months' bearing one may get as few as five or as many as
fifty flocky mushrooms; one or two may occur to-day, and we may not find
another for a week or two, when we may get a whole clump of them, and so
on. It is not the large number of them that makes them dangerous, for
they never appear in quantity. They sometimes appear among the earliest
mushrooms in the bed, but generally not until after the bed has been in
bearing condition for a week or two.

What conditions are most favorable or unfavorable to the growth of this
disease I do not know; but it is certainly not caused by debility in the
mushroom itself, as the parasite attacks healthy, robust mushrooms and
debilitated ones indiscriminately. This flocky condition is caused by
one or more saprophytic and parasitic fungi of lowly origin, whose
various parts are reduced to mere threads, simple or branched, and
divided into tubular cells at intervals, or else they are long,
continuous microscopic tubes without any partitions, except at those
occasional points where a branch, destined to produce spores, is given
off. Generally two or more species of these thread-fungi are present at
the same time on the mushroom host, and by the multiplied crossing and
interweaving of their threads and branches produce, through their great
numbers, the whitish, felted mass of "flock"; while as individuals the
threads are so minute as to be scarcely or not at all visible to the
naked eye. Similar thread-fungi may often be found in the woods among
damp leaves, under rotten logs, and on those porous fungi which
project, shelf-like, from the trunks of trees. At present there is no
way known for destroying the "flock," except to take