PSATHYRELLA DISSEMINATA 55 



published a monograph on the genus Coprinus in which he described 

 in detail thirty- three species found in Denmark. In respect to 

 Psathyrella disseminata, he followed Quelet, for he described this 

 fungus as a Coprinus and placed it in his section Nudi.^ 



I have no doubt whatever that Quelet and Lange are in error 

 in placing Psathyrella disseminata in the genus Coprinus and have 

 so expressed myself in another place. ^ My reasons for holding this 

 view will now be given in as concise a form as possible. 



The chief points in connection with the mechanism for the pro- 

 duction and liberation of spores in the genus Coprinus, i.e. in the 

 Inaequi-hymeniiferous Type,^ may be summarised as follows : 



(1) The gills are very thin, 



(2) The gills are parallel-sided or subparallel-sided, 



(3) The gills are not positively geotropic, 



(4) Usually the hymenium on one side of a gill at maturity 



looks slightly downwards and that on the other side 

 slightly upwards, 



(5) The spores ripen in succession from below upwards on each 



gill, 



(6) The spores are discharged in succession from below upwards 



on each gill, 



(7) Autodigestion proceeds from below upwards on each gill 



and removes those parts of the gills which become spore- 

 free and which, if they continued in existence, would 

 become mechanical hindrances to the fall of the remaining 

 spores. 

 All the facts just given are correlated with one another. In 

 the genus Coprinus the ripening and discharge of the spores from 

 below upwards on each gill, and the autodigestion from below 

 upwards on each gill, are special arrangements which permit of 

 successful spore-discharge from parallel-sided non-geotropic gills. 



1 Jakob E. Lange, " Studies in the Agarics of Denmark," Dansk Botanisk 

 Arkiv udgivel af Dansk Botanisk Forening, Part ii, No. 3, 1915, p. 46. 



2 A. H. R. Buller, " Some Critical Remarks on the Generic Positions of Psalhyra 

 urticaecola Berk, et Broome, Coprimis plicafilis Fr., and Psathyrella disseminata 

 Pers.," Transactions of the British Mycological Society, vol. v, 1917, pp. 482-489. 



3 These points were discussed at length in vol. ii, 1922, ch. ix, and will be treated 

 of in detail in the chapters devoted to a description of the Coprinus Sub-types. 



