128 FLOWERLESS PLANTS 



says. Here and there cases are to be found 

 in which the mycelium is coloured brown or 

 red. Sometimes the mycelium on the fungus 

 is composed of only a few threads, whilst on 

 other occasions it may be in the nature of a 

 great mass. In certain species there is a ten- 

 dency to form a hard, thick body, which is 

 called a rhizomorph. One of the best known 

 examples is to be found in the case of the 

 Honey Agaric {Armillaria mellea), an exceed- 

 ingly common pale brown species which is 

 found in clusters at the base of tree-trunks. 

 The rhizomorphs of this fungus are frequently to 

 be found between the bark and the wood of 

 trees which are more or less in a state of decay. 

 A somewhat similar form of mycelium is that 

 which is in the form of a rounded nodule, tech- 

 nically a sclerotium. These are very largely to 

 be seen in the case of many parasitic fungi, and 

 their production arises quite frequently when 

 the host plant is djdng. It is likely that the 

 sclerotium conserves the energy of the mycelium 

 in some way, that before it perishes altogether 

 the production of a fruiting process is possible. 

 Quite often rhizomorphs are phosphorescent. 

 With those who live in woodland districts it 



