76 The Tree and How it Dies 



a worm bored a little hole in the tree we see 

 here. Soon after, the spores of some fungus came 

 flying along through the air and one of them fell 

 into this same small hole in the tree's bark. 

 There it began to grow, and from the seed once 

 so small came this great white bunch. It is still 

 growing, slowly but surely. The sound wood is 

 beginning to decay, and in time this fine large 

 tree will die. 



Diseases usually attack trees where the bark 

 has been cut or torn from the living wood inside. 

 Here the small seeds find a place to grow, and 

 soon cause the wood to rot where it was sound 

 and healthy before. There are some fungi that 

 live only on the bark and wood, where they soon 

 produce cankers and swellings. Some of these 

 swellings on the bark look so much like small 

 shelves or seats that they are called " bracket 

 fungi." But not all of the fungi living on the tree 

 look like this. One of the mildews is like a fine 

 white powder on the tree's bark. Then, there are 

 some fungi that are always found on the tree's 

 roots, while still others attack only the leaves, 

 covering them with little spots. 



There is one fungous disease which is killing 



