44 



RESEARCHES ON FUNGI 



The Gills. — The gills are usually 6-10 mm. long, but varying in 

 the largest fruit-bodies up to 17 mm. long ; 1- 5-3-0 mm. broad ; 

 parallel-sided, except near the furrows in the flesh where they are 

 somewhat expanded (Fig. 24, p. 41) ; and in their unexpanded 

 part 0-1-0 -15 mm. thick, the thickness being measured between 

 the outer walls of the two layers of paraphyses. While they resemble 

 the gills of C. curtus in their mode of spUtting from above down- 

 wards, they differ from them 

 and the gills of all other 

 Coprini in that they are non- 

 D deliquescent. The free edges 

 of the long gills are white with 

 swollen sterile cells, and those 

 ^^^i- of the short gills bear cheilo- 

 cystidia (Fig. 24, p. 41). 



The Hymenium. — The hy- 

 menium consists of para- 

 physes, basidia, and cystidia, 

 and is typically coprinoid in 

 structure. 



The paraphyses are welded 

 together laterally in the usual 

 way so as to form a con- 

 tinuous membrane in which 

 the basidia are inserted, and 

 from five to eight paraphyses 

 surround each basidium and isolate it from its neighbours (Figs. 28 

 and 31). 



The basidia are irregularly dimorphic-trimorphic : in some places 

 on the hymenium they appear to be dimorphic, while in other 

 places they are distinctly trimorphic (Figs. 29 and 31). The only 

 other Coprinus in which I have observed basidial trimorphism is 

 C. niveus. As a rule, each basidium bears four spores but, as in 

 C. niveus ^ and other Coprini, one finds here and there, among the 

 normal basidia, abnormal basidia bearing three or five spores 

 (Fig. 30). 



1 These Researches, vol. ii, 1922, p. 320, Fig. 110, b, c. 



Fig. 28. — Coprinus plicatilis. Surface view 

 of part of the hymenium which has shed 

 its spores and is exhausted : I, the long 

 basidia and the basidia of intermediate 

 length, not here distinguished from one 

 another but all shaded alike ; s, the short 

 basidia, left unshaded \p, the paraphyses, 

 now expanded to the maximum extent. 

 Material obtained at Kew, England. 

 Magnification, 293. 



