precaution should be taken to avoid these difficulties. Some of the 

 most common troubles reported in this counti;y are as follows:- 



Fogging Off — During the pin-head or button stage, and some- 

 times even later, the mushrooms which may be appearing in quan- 

 tity, turn brown, cease to grow, and soon decayv This is supposed 

 to be a physiological trouble; that is, one caused by a lack of essential 

 conditions. Molds and bacteria may play a secondary part at least 

 in producing this disease. It is most frequent in warm weather. 



Black Spot — This disease manifests itself by the appearance of 

 small discolored areas on the surface of the cap. It is said to be due 

 to improper watering and to lack of proper ventilation. 



Fungous Diseases — There are several fungous diseases of the 

 mushroom, none of which, however, has been of serious importance 

 in this country, and reference to them may, therefore, be omitted 

 in this place. 



Mites — There are one or two species of mites constantly to be 

 found in compost heaps, which may be injurious in the mushroom 

 bed. They are seldom troublesome at a temperature of less than 

 50 deg. F., as they are then more or less sluggish; and, although they 

 may be found upon the mushroom, they do little or no harm. At a 

 higher temperature they are supposed to destroy the spawn to a cer- 

 tain extent and owing to their great numbers, they are at least objec- 

 tiontable upon the mushrooms. 



Wood Lice, or "Sow Bugs." — These crustaceans, like the mites, 

 are not of great importance where the conditions of temperature are 

 favorable. The best methods of extermination are by trapping 

 and poisoning them. This may be done by putting pieces of potato 

 smeared with arsenic or Paris green, together with some dry rubbish, 

 into tin cans or boxes placed on the side. Most of the sow bugs that 

 enter these receptacles will be killed by eating the poison. 



Snails — Snails and slugs are frequently pests in mushroom grow- 

 ing, but they may be readily trapped by the use of lettuce or cabbage 

 leaves. 



Springtails — Springtails may become a source of great annoyance 

 when mushrooms are grown in damp caves. As a rule, they can 

 only establish themselves when carelessness has been shown in clean- 

 ing out old bedding material. When once established they mul- 



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