CHAPTER I 



THE PHENOMENON OF PUFFING IN SARCOSCYPHA 

 PROTRACTA AND OTHER DISCOMYCETES 



Introduction — Historical Remarks — Puffing illustrated by Photography — The 

 Significance of Puffing — The Genus Sarcoscypha — Sarcoscypha prolracta — The 

 Perennial Pseudorhiza — The Direction of Puffing and the Campanulate Form 

 of the Apothecium — The Ascus as an Explosive IMechanism — Radial-longi- 

 tudinal kSections and Surface Views of the Hymenium — Correlations and Fruit- 

 body Efficiency — What Factor determines the Oblique Position of the Opening 

 of each Ascus ? — ^Experimental Proof that a Fruit-body, when it puflfs, pro- 

 duces a Blast of Air — The Cause of the Blast of Air — The Blast of Air and the 

 Dispersal of the SiX)res — Concluding Remarks. 



Introduction. — In all the Basidiomycetes which violently dis- 

 charge their basidiospores, namely, the Hymenomycetes, the 

 Uredineae, Tilletia, and the Sporobolomycetes, every basidiospore 

 is shot away as soon as it has attained maturity ; and, since the 

 basidiospores ripen in succession, they are discharged in succession. 

 The result is that the liberation of basidiospores from the fruit- 

 bodies of the Hymenomycetes, from the teleuto-sori of the Rust 

 Fungi, from cultures of the myceHum of Tilletia, and from cultures 

 of Sporobolomycetes is a steady and continuous process, occupying 

 many hours, days, weeks, or even months, according to the species 

 or the cultural conditions. Spore-deposits made from any of these 

 fungi become denser and denser as the hours go by. Of all the 

 numerous species included in the groups of Basidiomycetes here 

 under discussion there is not one in which the basidiospores are given 

 off in sudden dense clouds at intervals determined by internal 

 organisation or external conditions. 



In the Discomycetes, on the other hand, as is well known, there 

 are many species the fruit-bodies of which exhibit the phenomenon 



of puffing, i.e. which, when subjected to certain changed conditions, 



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