430 



however, and when they begin to dry up water should be applied in 

 a fine spray on and around the beds. 



The first crop of mushrooms may be expected in about one and 

 one-half or two months after spawning, and one should be able to pick 

 some every day or two for two or three months. They should be 

 picked before the inner veil breaks and sent to market immediately. 

 When all precautions have been taken, however, there may be "crop 

 failures" due to the presence of mushroom mites, which may destroy 

 the mycelium as fast as it grows from the spawn, or to animal or 

 plant parasites. When a bed has ceased to produce, the material of 

 which it is made up must be entirely cleaned out and the Ijed remade 

 with new material. 



Food Valui; of Mushrooms 



The value of mushrooms as articles of food lies chiefly in their 

 flavors. If we were to measure their food-value by the amount of 

 energy that can be obtained from them, they would not rank very 

 liigh. On that basis the food-value of the cultivated mushroom is 

 just about the same as that of cabbage, less than one-half that of pota- 

 toes, or about one-twelfth that of wheat flour. Oysters have a food- 

 value considerably less than that of potatoes but nevertheless most of 

 us enjoy oysters because of their flavor, and most of us can enjoy 

 mushrooms as soon as we learn a few species so that we can eat them 

 without fearing that they will end our earthly existence. The market 

 price of mushrooms is prohibitive to the great mass of people, but 

 there are tons of excellent wild species which are allowed to decay in 

 the woods and fields every year. These will furnish variety and flavor 

 to the daily menus of thousands of families, at a cost only of the time 

 taken to collect them, as soon as people have learned to distinguish 

 them one from another. 



Poisonous Properties of Mushrooms 



The genus Amanita is by far the most dangerous group of mush- 

 rooms. Amanita vcrna (page 449) and its very near relative Amanita 

 pJialloidcs have probably caused more deaths in this country than any 

 other species. The active poison in these and closely related species 

 is known as the Amanita toxin. Its chemical nature is not yet under- 

 stood and no antidote for it is known. The clinical symptoms in 

 poisoning by these mushrooms are practicallv always the same. For 

 six to fifteen hours after the mushrooms have been eaten no discom- 

 fort is felt. The patient is then suddenly seized by a severe abdominal 

 pain, cramp-like in character and accompanied bv vomiting. Parox- 

 ysms of pain and vomiting alternate with periods of remission, and 



