456 



BASIDIOMYCETES. 



numerous branches like the runners of some hanging plant, e.g. 

 Aaron's Beard {Saxifraga sdrmerdosa). The rhizomorphs live as 

 saprophytes and have been long known to emit phosphorescent 

 light. Sporophores are developed directly on them, and if one 

 sows the spores, a delicate hyphal tissue is produced, which, 

 under suitable conditions, passes gradually over into the rhizo- 

 morph-strand. Brefeld succeeded in raising rhizomorphs from 

 spores in artificial nutritive media. 









Fio. 285. — Agaricus melleun near a Beech-stool, (v. Tubeuf phot.) 



The ^p'aricMs-myeelium forms fan-shaped snowy-white firm 

 membranous expansions under the bark of newly killed or still 

 living trees. They are quite distinct from the much more delicate 

 mycelial expansions of Polyponcs annosvs, and offer a particularly 

 easy means of distinguishing between the two species. Another 

 indication of Agaricus is the great outflow of resin from the bark 

 at the base of the stem and from roots, whereby hard clumps of 

 earth are formed round the roots. The passage of the rhizomorphs 

 into the white membranous mycelium is easily observed. The 



