20 



A cluster of cup-fungi (Sclerotinia) pufifing their spores. 



Spore Dispersal 



One of the most interesting phenomena in connection with this 

 group of fungi is that of the pufhng of their spores. The spores 

 in this type of fungus are borne in sacs, for the most part cyHn- 

 drical, and usually eight in each sac or ascus. These are held 

 under tension. At the slightest atmospheric disturbance, 

 thousands or perhaps millions of these sacs discharge their 

 contents into the air where the minute spores appear like a 

 cloud of dust and are borne away by the slightest breeze. 

 Through the courtesy of Cornell University, I am permitted to 

 reproduce the rather remarkable photograph made by Mr. 

 Fisher, photographer for the Department of Plant Pathology of 

 that institution. Anyone collecting cup-fungi will be able to 

 observe the smoking or puffing of their spores. 



Explanation of Plate 



1. Spring or honeycomb mushroom, Morchella esculenta. 



2. Fluted Acetabula, Acetabula sulcata. 



3. White saddle-fungus, Helvetia crispa. 



4. Common Acetabula, Acetabula vulgaris. 



5. Brain-fungus, Gyromitra esculenta. 



6. Revolute cup, Peziza repanda 



