CHAPTEE XV 



DISCOID FUNGI DISCOMYCETES 



This is one of the most interesting groups of the Ascomycetous 

 Fungi, in which the sporidia are contained in membranaceous 

 sacs, or asci, and when mature expelled from the apex, often 

 in a little smoky cloud, under the influence of sunlight. The 

 normal appearance is that of a cup or saucer, at first deeply 

 concave, but at length more or less expanded and flattened, 

 ranging in size from that of a pin's head to several inches. 

 The hymenium, or spore-bearing surface, is uppermost and soon 

 exposed, very often of a bright and attractive colour. We may 

 assume that this bright coloration is of some service to the 

 plant, but at present that use has not been determined. One 

 important feature, in which the majority of the discoid Fungi 

 differ from the majority of the Pyrenomycetal Fungi, is in their 

 fleshy or waxy substance, which is modified in one direction 

 until it becomes soft and tremelloid, and in the other direction 

 it is rather tough and leathery, but never really brittle and 

 carbonaceous. 



It will be better, in the first instance, to attempt a descrip- 

 tion of a typical discoid Fungus such as was formerly known 

 by the name of Peziza, although the old genus Peziza is now 

 broken up into a number of smaller genera. The general form, 

 when young, is either globose, or when possessed of a stem, 

 clavate, or club-shaped, pierced with a pore at the apex. As 

 growth proceeds, the pore enlarges and the head gradually 

 becomes cup-shaped, so that the Fungus resembles a wine-glass ; 

 the disc or lining of the cup flattening with age until it is 

 almost a plane surface. The outer surface, or excipulum, as 



