396 NATURE-STUDY 



Fungi play an important part in the economy of nature. 

 Many species grow in the wood of trees. They generally 

 enter the tree as a spore by some wound, as a scar, or broken 

 branch. From this point the vegetative fibres of the fungus 

 ramify through the wood, killing the living tissues, weaken- 

 ing and rotting the wood, so that it is often ruined for tim- 

 ber. Such fungous decay generally results in the death of 

 the tree. The fungus continues its work, until finally the 

 tree is so much weakened that it is blown down in some 

 storm. Still the work of the fungus goes on. The fallen 

 tree decays, crumbles, and is added to the mould on the 

 forest floor. In time the substance of the tree is practically 

 entirely decomposed and returned to the air and the soil 

 from which it originally was derived. In this work of decay 

 fungi are really beneficent agents. Though it is pathetic to 

 see a fine tree decay, yet every tree reaches a period of ma- 

 turity and then declines, and should finally make room for 

 new growth. If it were not for the work of the fungi and 

 bacteria of decay, the dead trees would so choke the forest 

 that no new growth could develop. 



