Ch. X] 



THE TOADSTOOLS 



473 



their colors, which are remarkably diverse, and often bright 

 and even beautiful. 



In many of this group, the mycelium is perennial, and, 

 developing in humus, spreads radiately outward, probably 

 away from its own excretions. 

 Thus the sporophores of one year 

 form a ring, which enlarges each 

 season; and such is the origin of 

 the well-known Fairy Rings (Fig. 

 330). A member of this order pro- 

 duces in wood the material which 

 makes it phosphorescent in the 

 dark. Another (Rozites gongylo- 

 phora) is actually cultivated as a 



food plant by Certain tropical ants. Fig. 332. — Boletus subtomen- 



In the galleries of their nests, they tMW;X ^ (From Bailey - } 

 grow the mycelium on leaves collected for the purpose, and 

 feed upon enlarged protoplasmic bodies formed in great num- 

 bers at the ends of the hyphse. These bodies are of wholly 



^^^J^IW^PP 



Fia. 333. — A Bracket Fungus, Polyporus bctulinus, on a Birch; X $• 

 (Drawn from a photograph.) 



vegetative nature, and in order to cause their continuous 

 production, the ants regularly destroy the sporophores. 



