498 BRITISH lUNGI 



RmziNA 



x'\scophore sessile, exj)anded from the first, more or less plane, 

 attached by numerous root-like fibrils springing from the whole of 

 the under surface (spores fusiform, colourless, i -celled). 



Known by the crust-like ascophore attached to the substratum 

 by numerous tufts of fibrils. 



R. infiata. — Crust-like, flattened generally, more or less convex, 

 wavy or nodulose, bay-brown or umber, edge slightly raised and 

 paler, thick, fleshy, irregularly orbicular or often lobed ; spores 

 i-celled, fusiform, colourless or with a tinge of brown at maturity, 

 smooth, 32-36x9-10 ji). 



On sandy soil that has been burnt, peaty ground, heaps of saw- 

 dust, etc. Said to be parasitic on the roots of trees, 



Sub-Order Pyrenomycetace^ 



Some of the families constituting this very extensive group of 

 fungi include species that are of comparatively large size. Daldinia, 

 a smooth, subglobose fungus of a pitch-black colour, is not un- 

 common on old wood. When cut open, the dusky, solid interior 

 is seen to be marked with concentric lines or rings. The entire 

 fungus varies from 1-2 in. in diameter. If the circumference of a 

 section of Daldinia is examined with a pocket lens, it will be seen 

 to be studded with minute subglobose or flask-shaped cavities. 

 These flask-shaped bodies or perithecia contain the asci that pro- 

 duce the spores ; each perithecium has an opening or mouth at its 

 summit, through which the spores escape at maturity. The mouth 

 of each perithecium opens at the surface of the fungus. If the 

 surface of a Daldinia is examined under a pocket lens, its appa- 

 rently smooth and even surface is seen to be studded with myriads 

 of very minute pinprick-like markings, each of which corresponds 

 to the mouth or opening of a perithecium. If a mature specimen 

 of Daldinia is placed on a piece of white paper and covered over with 

 a tuml:)ler and left till next .day, the surface of the fungus and the 

 surrounding paper will be found covered with a black, sooty 

 powder, which on examination under a microscope will pro\-e to 

 consist of innumerable elliptical, dark brown spores, as seen by 

 transmitted light, but which appear black in the mass. 



If the foregoing description has been grasped, it will be seen that 

 the spore-bearing portion of the fungus is confined to the periphery, 

 the remainder of the solid mass being sterile, and called the stroma. 



The genus Xylaria is, perhaps, more commonly distributed than 

 Daldinia ; in fact, it would be almost inconceivable for anyone to 

 collect fungi for an hour in a wood, w^iere stumps or fallen branches 

 abound, without coming across specimens of the " candle-snuff 

 fungus " {Xylaria hypoxylon, PI. XXXVIII, fig. i). X. polymorpha 

 (PI. XXXVIII, fig. 9), although perhaps not so abundant as 



