o 
A MUSHROOM. 17 
Are they beneficial or injurious? How? 
Why do they expose to the air their spore-bearing 
portions? 
Is the plant useful as a carbo-hydrate or a nitroge- 
nous food? 
What is the mutual relationship of these plants and 
insects? 
Are the spores few or many? Place on a glass’ 
plate a pileus with its spore-bearing surface down- 
ward, and cover. Examine after a time and ob- 
serve the result. How do you explain it? 
