CHAPTER IX 



THE ATRAMENTARIUS SUB-TYPE ILLUSTRATED BY 

 COPRINUS ATRAMENTARIUS 



CJiaracters of tlie Atramentarius Sub -type — Representative Species — Coprinns 

 aframentariits. Preliminary Remarks on the Function and Fate of the Cystidia 

 — ^Distribution and Habitat — General Description of the Fruit-bodies — ^The 

 Geotropism of the Stipe — The Structure of the Gills — The Pi'ocess of Spoi'e- 

 discharge — The Function and Fate of the Cystidia during Spore-discliarge — 

 The Interlamellar Spaces — -Summary concerning the Structure and Function 

 of the Cystidia — The Pilei of Coprinns airamentarius and C romalus compared 

 — The Pileus-flesh — Other Copiini belonging to the Atramentarius Sub-type 



Characters of the Atramentarius Sub-type. The Atramentarius 

 Sub-type of fruit-body possesses all the essential characters already 

 described for the Inaequi-hymeniiferous or Coprinus Type : (1) the 

 gills are very thin, (2) the gills are parallel-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, (0) the spores are discharged in succession 

 from below upwards on each gill, and (7) autodigestion proceeds 

 from below upwards on each gill and removes those j^arts of the 

 gills which have become spore-free and which, if they continued in 

 existence, would become mechanical hindrances to the fall of the 

 remaining spores. 



The special characters of the Atramentarius Sub-type which 

 enable one to differentiate it from the other Coprinus Sub-types are 

 as follows : 



(1) The gills are parallel-sided. They therefore differ from those 

 of the Comatus Sub-type which are subparallel-sided and flanged. 



(2) Cystidia are present in large numbers on the faces of the 



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