INSECT AND OTHER ENEMIES. 
125 
diseased it continues to be diseased, and it is a fact that 
if one mushroom in a clump has black spot we usually 
find that every mushroom in the clump has it. But 
mushrooms growing from the same bit of spawn and that 
come up an inch or two away from the spotted ones may 
be perfectly clean. Black spot has never occurred with 
me in new beds, and seldom in those in vigorous bearing, 
but it generally appears in beds that have been in bearing 
condition for some weeks or are declining. It does not 
confine itself to any particular 
spot or part of the bed, and some¬ 
times it is much more plentiful 
than at others. Between Octo¬ 
ber and March we have very little 
black spot, but as the spring opens 
this disease increases. During 
the winter season, with careful 
attention, perhaps not so much as one per cent will 
show black spot, but as the warm weather sets in the per 
Fig. 25. Mushroom af¬ 
fected with Black Spot. 
centage increases until in May, when as many as twenty 
per cent may be affected by it. 
Black spot is a disease, however, that can be con¬ 
trolled. Keep everything in and about the mushroom 
houses rigidly clean, and as soon as a bed has ceased to 
bear a crop worth picking clear it out, lime-wash the 
place it occupied, and make up another bed. Carefully 
observe that no old loam or manure is allowed to accu¬ 
mulate anywhere, or green scum forms upon the boards, 
paths, or walls; boiling w^ater impregnated with alum 
poured over the boards, walls, and other scum-covered 
surfaces, will kill the eel worms, but it should not be 
allowed to touch the mushroom beds that are in bearing 
or coming into bearing. Much can be done to protect 
the bearing beds from the ravages of this pest: In 
gathering the mushrooms remove every vestige of old 
stump and fogged-off mushrooms, keep the holes filled 
