HOW TO USE THE KEY 



The reader should bear in mind the fact that there exist 

 hundreds — perhaps thousands — of species of mushrooms and 

 that mistaken identification might result from superficial 

 attention to descriptions of the comparatively few kinds of 

 plants dealt with in this book. 



No plant key can be perfect. There are species very difficult 

 of identification even by expert specialists. Should the reader 

 fail to identify a collected species after careful use of the key, 

 his non-success will be probably due to the fact that his speci- 

 men is not one of our common mushrooms. Botanists able 

 and willing to identify specimens sent to them, may be found 

 in many of the larger universities, at State capitals and at the 

 United States Department of Agriculture in Washington. 



27 



