36 DISEASES OF DECIDUOUS FOREST TREES. 



the appearance of but one or two sporophores, it may often be pos- 

 sible to save a considerable amount of wood and lumber. If only 

 the sporophores are removed and the trees left standing, the fungus 

 continues growing in the tree, and every year that such a tree is left 

 in the forest it depreciates in value, and ultimately becomes entirely 

 worthless. The removal of diseased trees should be undertaken no 

 matter to what species they may belong. So far as we now know, 

 Fomes igniarius when growing on one host species may infect the 

 others, and in a deciduous forest a diseased maple must be consid- 

 ered a source of danger for the other host species until it is shown 

 that the maple fungus is a distinct form which can not infect other 

 species. In the absence of such proof it is advisable to cut down 

 the diseased maple and make the protection of the remaining trees 

 certain. 



Any examination of a forest tract for diseased trees should be 

 made thoroughly, so that all diseased trees may be removed, for the 

 existence of a single tree bearing a number of actively growing sporo- 

 phores is sufficient to cause the infection of a large area, since the 

 spores of the false-tinder fungus are very light and are blown to 

 great distances by the wind. All diseased wood should be burned, 

 as sporophores continue to develop on diseased wood even after 

 being cut from the tree. 



Where trees are sufficiently valuable to warrant their being treated 

 individually, careful wound protection is advisable. Wherever a 

 branch of any size breaks off or where deep wounds are produced in 

 the trunks of trees, such wounds should be carefully trimmed so 

 that the surfaces are smooth. The wounds should then be coated 

 with some good antiseptic substance which can be rapidly applied 

 and which will have sufficient penetrating power to infiltrate for a 

 distance into the wood fiber. The best material for this purpose is 

 coal-tar creosote. This should be heated until thoroughly liquid, 

 when it can be applied with a paint brush. It not only has the 

 distinct advantage of killing all fungous spores which may be pres- 

 ent or which may subsequently lodge in the wound, but it is also a 

 good preventive against boring insects. 



The painting of wounds is especially advisable where such wounds 

 are large. One instance which occurs to the writers where such 

 wound treatment would have proved very advantageous if it had 

 been carried out in time was in a large tract of chestnut forest. 

 The large trees had been cut out a number of years before the 

 writers' observations were made, and shoots had started from the 

 bases of the old stumps. These shoots were sufficiently old to have 

 formed heartwood. A large percentage of these young trees were 

 found affected at the base of their trunks, the fungus having entered 



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