SPORE DISCHARGE AMONG ASCOMYCETES 189 



Spore discharge among Discomycetes. Evidently the earliest 

 observations of ascospore discharge were made upon the larger 

 Discomycetes. Micheli (1729) described spore ejection of Peziza 

 as being "like smoke." Bulliard (1791) recorded that "their seeds 

 ascend like steam," if the observer shakes the fructifications or 

 blows his breath upon them. De Albertini and de Schweinitz 

 (1805) saw "clouds of smoke" in Rhytisma salicinum. A very 

 graphic account of spore discharge by Morchella gigcis is given 

 bv Plowright (1880-81), who observed the spore cloud as seen 

 against a dark background with the aid of a beam of light: "When 

 acted upon by a gentle current of air such as would be produced 

 by gently waving the hand, it swayed to and fro without mani- 

 festing any tendency to become dispersed. The component spo- 

 ridia were in constant motion, rising and. falling and circling 

 about, as if the law of gravity were a myth, existing only in the 

 imagination of philosophers. When the cloud was quite blown 

 away by a more powerful air current, it, in the course of a few 

 seconds, reformed." In his chapter on the liberation or purring 

 of spores by Discomycetes Buller (1934) assembled many inter- 

 esting features from the accounts of early observers and added 

 the results of his own observation and experimentation and those 

 of his contemporaries [Falck (1916), (1923)]. 



Dickson and Fisher (1923) described a technique for photo- 

 graphing discharge by Sclerotinia libertiana that is applicable to 

 other large Discomycetes. Buller's (1934) observations show 

 that Sarcoscypha protracta can become a miniature geyser, hurl- 

 ing a column of spores to a height of about 3 in. before the spores 

 lose their vertical momentum and begin to be dispersed into a 

 cloud. The puffing by Urmda geaster, having ascomata which, 



