6o RESEARCHES ON FUNGI 



Here the stipes are very long. Finally, Fig. 39 shows the largest 

 fruit-body that has been observed. Its stipe is 15 cm. long and 

 its pileus 2-25 cm. broad. 



Coprinus longipes, as I remarked,^ " resembles C. plicatilis in 

 general appearance and might be mistaken for it ; but it differs in 

 coming up on horse dung instead of in grassy places, in having a 

 sHghtly smaller depressed disc, in having gills which waste or 

 dehquesce at their edges instead of remaining entire, and in having 

 a stipe which is usually longer." 



Coprinus longipes is of interest to us here owing to the fact that, 

 while in its general appearance and many of its histological details 

 it greatly resembles C. plicatilis, the edges of its gills but not the 

 whole of its gills undergo a distinct although a very limited amount of 

 autodigestion. Thus C. longipes serves to connect C. plicatilis, the 

 giUs of which do not undergo autodigestion, with the typical Coprini, 

 e.g. C. comatus, C. niveus, and C. stercorarius, in which the auto- 

 digestion of the gills is a very marked characteristic. 



A Taxonomic Description of Coprinus plicatilis. — The descrip- 

 tion of Coprinus plicatilis which follows is based on my own studies 

 of this species, and has been drawn up with a view to its being of 

 some use to taxonomists. The taxonomic descriptions of C. plica- 

 tilis hitherto given have all been relatively brief and incomplete. 

 Massee,^ in his British Fungus-Flora, describes the pileus as 

 "eventually becoming plane, the margin splitting and revolute ; " 

 but this is erroneous, for the pileus when fully expanded is broadly 

 convex while its margin usually remains unsplit and is never revolute. 

 The same author,^ in A Revision of the Genus Coprinus, does not 

 mention the fact that cystidia are present on the sides of the gills 

 of C. plicatilis, and he fails to show any cystidia in his drawing of 

 a transverse section of the pileus in which whole gills and the details 

 of their hymenium are represented. Perhaps the most important 

 omission from previous descriptions of C. plicatilis is that the gills 

 remain dry and are not destroyed by deUquescence. 



1 G. R. Bisby, A. H. R. Buller, and J. Dearness, The Fungi of Manitoba, 

 London, 1929, p. 118. 



2 G. Massee, British Fungus-Flora, London, 1892, vol. i, p. 328. 



^ G. Massee, "A Revision of the Genus Coprinus," Annals of Botany, vol. x, 

 1896, p. 177, Plate X, Fig. 25. 



