COPRINUS PLICATILIS 137 



:Myc. Soc, 1917, Vol. V, p. 485. Pileus about 5 mm. in diameter 

 in the hemispherical condition, almost spherical at first, becoming 

 hemispherical at the time the spores begin to ripen, opening out 

 and even becoming revolute and radially split during the discharge 

 of the spores, chalky white, unstriated, beset with numerous small 

 white scales composed of matted hyphae unmixed with globular 

 cells and not bearing crystals of calcium oxalate. Gills very thin, 

 about 0-1-0 '15 mm. thick, ventricose, maximum width I'o mm., 

 at first white, then becoming chocolate, the coloration proceeding 

 from below upwards, held together by cylindrical -ovate cystidia 

 which cross the interlamellar spaces as in Coprinus oimmenfarius, 

 and undergoing complete autodigestion in the evening and night. 

 8tipe when fully elongated 1-5-2 cm. high, 2 mm. thick below, 

 attenuated upwards, scarcely more than 1 mm. thick at the top, 

 white, flocculent at the very base, otherwise smooth, when pulled 

 from the wood to which it is attached leaving a small discoid piece 

 of itself behind, hollow. Spores minute, 7 X 4 /i, oval, smooth. 

 Spore-discharge and autodigestion of the gills taking place in the 

 evening and night. 



On sticks, also on dead leaves and haulms of a grass (Holcus 

 lanafus), Queen's Cottage Grounds, Kew, June, 1912. 



Coprinus plicatilis.— Massee,i in 1906, stated that " many species 

 included in Coprinus, as C. pUcatilis and others having dry non- 

 deliquescent gills, have no real affinity with this genus " ; and, on 

 mycological excursions, I have heard the suggestion put forward 

 that C. pUcatilis (Fig. 56) is rather a Psathyrella than a Coprinus. 

 The true generic position of this fungus, therefore, appears to be a 

 matter of some doubt. 



For a number of j^ears I have had excellent opportunities for 

 examining the structure and mode of spore-discharge of the species 

 in question. 1 find that all the seven criteria for a Coprinus are 

 satisfied except one : there is no autodigestion of the gills from 

 below upwards. The gills are (1) very thin, for they are not more 

 than 0-15 mm. thick, (2) parallel-sided, and (3) non-geotropic, a 

 fact decided by experiment. Since the gills are parallel-sided and 

 non-geotropic, it must of necessity happen that (4) one side of a gill 

 1 G. Massee, Text-Book oj Fungi, London, 1906, p. 364. 



