2 FUNGUS-FLORA. 



together, and leaving only a narrow slit or opening, through, 

 which the mature spores escape from the almost concealed 

 disc. In some cases the base of the ascophore is narrowed 

 below and prolonged as a stem-like structure, when it is said 

 to be stipitate ; when the stem is entirely absent, it is sessile. 

 When a sessile ascophore is seated quite on the surface of the 

 substratum or matrix, the substance on which it is growing, 

 it is superficial ; when more or less buried in the substratum, 

 but with the upper surface exposed, it is innate ; and when 

 it originates entirely below the substratum or matrix, and 

 bursts through during development, the ascophore is said to 

 be erumpent. The texture of the ascophore varies consider- 

 ably in different species ; when rather thick, parenchyma- 

 tous, and more or less brittle, it is described as fleshy ; carti- 

 laginous, when composed of interwoven hyphae, rather flexible 

 and tough: in the Hysteriaceae the excipulum is usually 

 carbonaceous, consisting of parenchymatous tissue, the exter- 

 nal walls being rigid, blackish, and brittle, and breaking up 

 into a carbonaceous mass when crushed. In Bulgaria and 

 allied genera the ascophore is gelatinous when moist, becom- 

 ing rigid and horny when dry. 



The texture and consistence of the ascophore are points of 

 primary importance in the discrimination of species, and 

 should always be noted. 



In numerous species the ascophore originates at once from 

 delicate, colourless hyphae that are almost completely buried 

 in the matrix ; in others, some of the hyphae come to the 

 surface, and form a more or less dense felt or subicalum, from 

 which numerous ascophores usually spring ; in a third type 

 the hyphae form a dense parenchymatous cushion or stroma, 

 from which the ascophores originate. 



Constituent parts of the ascophore. In several 

 species it has been demonstrated that the hyphae forming 

 the excipulum and basal portion are developed first, and the 

 paraphyses, which also belong to this portion, are formed 

 before the asci, the last-named being developed from per- 

 fectly independent ascogenous hyphae that are not in organic 

 continuity with the hyphae of the excipulum. During deve- 

 lopment the two systems of hyphae become much inter- 

 woven at the basal portion of the ascophore, and the growing 



