62 RESEARCHES ON FUNGI 



black zone. Spore-discharge period 1-4 hours, varying with the 

 size of the fruit-body, in progress in the late morning or early after- 

 noon, never at night. Spores black in the mass and jet-black 

 under the microscope, smooth, rounded heart-shaped to spindle- 

 shaped, pointed at the apex, with three differing dimensions, 

 12-9 X 10-7 X 7-9[jL (average of 50 spores on one fruit-body), but 

 in some fruit-bodies distinctly smaller (10 [x long) or even larger 

 (13-2 [X long), rather variable in size and shape. Basidia of two or 

 three differing lengths, each one surrounded by 5-8 paraphyses. 

 Cystidia on the sides of the gills with a thin cyHndrical stalk between 

 the paraphyses, ovoid-tapering, obtusely rounded at the free end 

 which is never united with the paraphyses of the opposing gill, 

 80-100 [I long, varying up to 150 y., 25-28 [i broad, disappearing 

 during the spore-discharge period. Common in England, Europe, 

 United States of America, Canada, etc., in damp, grassy places in 

 woods, in close-cropped pastures, on mown lawns, on grass borders 

 along roadways, etc., not recorded on dung ; during damp weather 

 in summer and autumn a new crop comes up each morning, sheds 

 spores about midday, and withers by the evening. 



This species is characterised by coming up in grassy places, by 

 its expanded, wheel-Uke, translucent pileus remaining broadly 

 convex and never becoming quite plane or revolute, by the inner 

 ends of the gills being united to form a sHght collar separated from 

 the stipe by a bare zone of flesh, by the deep-black more or less 

 compressed heart-shaped spores, and particularly by the gills never 

 undergoing autodigestion (dehquescence) but remaining dry and 

 intact during spore-discharge and until the whole fruit-body withers. 



Except for the absence of autodigestion, the gills are typically 

 those of a Coprinus ; for, as in the gills of all other Coprini, the 

 paraphyses are strongly developed, the basidia are heteromorphic 

 as regards length and unequal in protuberancy, and the spores 

 ripen on the gills and become discharged from the gills in succession 

 from below upwards. The nearest relative of C. plicatilis appears 

 to be C. longipes Buller, a species observed in central Canada, which 

 differs in occurring on horse dung and in having gills which at their 

 margins show a shght wasting or autodigestion during the spore- 

 discharge period. 



