134 MPSHEOOMS, HOW TO GROW THEM. 



tion, have kept the pieces of each brick close together, 

 and where flock has appeared I have failed to find tliat 

 the otlier pieces of spawn from that brick are more 

 liable to produce flock-infested muslirooms 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 mush- 

 rooms ; 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 beaiing 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 cer- 

 tainly not caused by debility in the mushroom itself, as 

 the parasite attacks healthy, robust mushrooms and debil- 

 itated 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, ezcept at those occasional 

 points where a branch, destined to produce spores, is 

 given ofE. 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 



