42 2 General Botany 



The spores of mushrooms are produced in unthinkable num- 

 bers either inside the fruiting body (puffballs) or on the under 

 side of the umbrella-shaped cap (mushrooms). A large puffball 

 has been estimated to contain 7000 bilHon spores ; the shaggy- 

 mane mushroom {Coprinus) about 5 billion spores on each pileus ; 

 and one of the bracket fungi produces about 100 bilhon spores 

 each year for several years. 



REFERENCES 



DuGGAR, B. M. Fungous Diseases of Plants. Ginn & Co., Boston; 1909. 

 Harshberger, J. W. Mycology and Plant Pathology. P. Blakiston's Son & Co., 



Philadelphia. 

 Hesler, L. R., and Whetzel, H. H. Manual of Fruit Diseases. The Macmillan 



Company, New York; 1917. 

 McIlvane, C, and Macadam, R. K. One Thousand American Fungi. Bobbs- 



Merrill Company, Indianapolis; 191 2. 

 Stevens, F. L. Fungi Which Cause Plant Disease. The Macmillan Company, 



New York; 1913. 

 Stevens, F. L., and Hall, J. G. Diseases of Economic Plants. The Macmillan 



Company, New York; 192 1. 



