40 RESEARCHES ON FUNGI 



that they were so large and that their spores were not typically 

 heart-shaped, ought to be included in C. plicatilis. 



Although for many years I have paid particular attention to 

 the genus Coprinus and have examined upwards of thirty of its 

 species, Coprinus hemerobius is still unknown to me as a distinct 

 species. That C. hemerobius is only a form of C. plicatilis is a view 

 also expressed by Lange.^ 



The Pileus. — The pileus of Coprinus plicatilis at first is greyish- 

 brown and ovate, then campanulate, and finally almost plane, 

 although still convex. Fine striae run from the margin of the 

 unexpanded pileus to the large disc, which is at first somewhat 

 umbonate but later becomes distinctly depressed (c/. Figs. 21 and 

 22). They mark the position of furrows in the flesh and are situated, 

 as in C. micaceus and C. curtus, above the lines of attachment of 

 the gills (Fig. 24), As the pileus expands, these furrows open out, 

 the upper parts of the gills become split into two halves from above 

 downwards, and the top of the pileus becomes rimoso-sulcate as in 

 C. curtus (cf. Fig. 18, p. 27, and Fig. 22, p. 37). This parasol-like 

 mode of opening permits of the pileus being fully expanded without 

 being torn into rays. The pileus, unlike that of C. ciirtus, never 

 becomes quite plane and then more or less revolute ; but, when 

 fully expanded, it is always convex (Figs. 21, 22, and 34, pp. 35, 

 37, and 51). The expanded pileus, as already pointed out, is 

 1 •3-2-5 cm. in diameter, varying up to 4 cm. The depressed disc, 

 which retains its brown colour when the rest of the pileus has turned 

 pale after the loss of the spores, is usually 4-5 mm. in diameter. 



The flesh of the pileus is relatively thick at the disc ; but, 

 where it covers the gills, it is extremely thin and divided into rays 

 by the furrows or sulcations already mentioned. The disc-flesh, in 

 the unexpanded pileus, is prolonged downwards 0- 5-1-0 mm. in 

 such a way as to surround the stipe with a closely fitting sheath 

 terminated below by a collar formed by the inner edges of the gills 

 (Fig. 25, A). 



The expansion of the pileus (Fig. 25) is accomplished by the 

 growth of the disc-flesh where this ensheathes the top of the stipe 



^ J. E. Lange, " Studies in the Agarics of Denmark," Dansk Botanisk Arkiv, 

 191.5, Part II, Coprinus, p. 49. 



