Diseases of Thnber 107 



includied most of the trees in the swamp, were attack- 

 ed, the disease being evident at some distance away, 

 because of the yellow color of the foliage. Early 

 in September the leaves dropped, and the trees robbed of their 

 foliar organs soon died. No sooner were they dead than various 

 saprophytes began their work, a shelf-fungus, as in Figure 7, 

 being one of the most frequent invaders. 



The wide-spread occurrence of these diseases is probably 

 greater than most people imagine. In the instance that I have 

 cited as coming under my own observation a considerable por- 

 tion of the swamp suffered. In Queen's Park, Toronto, few 

 sound oaks are to be found, nearly all being sapped by a Poly- 

 porus. Recently a research, instituted by the United States Gov- 

 ernment in South Dakota, showed that half of the standing timber 

 in the forests of that State, including the Black Hills Forest Re- 

 serve, had been killed by a certain disease, and that unless means 

 were speedily taken to check the trouble, the remaining trees 

 would go in the same way. 



Happilv the effects are not usually as dire as in the last in- 

 stance mt'ntioned, but even a casual observation of a forest shows 

 that many branches die from one cause or another, and that here 

 and there a tree has succumbed. The direct loss may not be 

 great, but dry fuel is furnished for fires, the results of which may 

 be disastrous. A safe remedy where it can be applied, is to re- 

 move matu.re timber, for it is most liable to disease, and all infect- 

 ed timber, no matter of what age. Unfortunately such a proce- 

 dure has not yet been found practicable on the reserves in Ontario. 



The successful treatment of cut and sawn timber for the 

 prevention of disease, is one of the problems that bids fair to 

 solution. Such timber is very liable to rot, especially if used in 

 a moist place. This is true of wood covered wholly or in part 

 by soil, as in the case of telegraph or telephone i)oles, fence posts, 

 railroad ties, bridge and foundation timbers, planks for pave- 

 mc^nts and so on. Frequenth'. to). timber often discolors, there- 

 bv depreciating in market value. Thus "green" and "blue" wqod 

 not uncommonly occur, the color in each case being due to the 

 presence of certain fungi, that either contain a pigment within 



