130 PROTECTION OF WOODS AGAINST 



quantities, often clogging together the soil round the tree. 

 In the soil will be found black or brown root-like growths, 

 termed rhizomorphs, which almost look like the leaf-stalks of 

 a maidenhair fern ; the thin, firm, white ribbon-like mycelium 

 will be found between the wood and bark at the base of the 

 tree. 



The trees usually die very shortly after being attacked. 



The fructifications or toadstools appear in numbers closely 

 collected together round the base of the stem or on the 

 surrounding ground in October, and are either of a bright 

 yellow colour, or of a dirty brownish yellow, and vary in 

 diameter from two to six inches. 



When one plant has been attacked infection spreads to 

 surrounding ones, as the rhizomorphs bore into the roots of 

 neighbouring trees. 



The fungus attacks nearly all conifers, of all ages, but 

 especially trees from four to fifteen years old. It also attacks 

 broad-leaved trees, living and dead, and is found on the stumps 

 of felled oak and beech. Here it does no harm, but it spreads 

 to conifers planted among these stumps, and is then destructive. 

 It also attacks gate-posts and other dead timber placed in the 

 ground. When the disease has appeared steps should be at 

 once taken to prevent it spreading. All conifers attacked 

 should be dug up with their roots, and these latter should be 

 burnt. 



The ground around the plant may be trenched and all 

 rhizomorphs collected and burnt. Where the surrounding 

 trees appear healthy a small trench, a foot deep, should be 

 dug round the attacked plant, or group of plants, at some 

 little distance away, so as to prevent the rhizomorphs spreading. 

 This is best done in autumn when the toadstools are visible, 

 so that the whole area can be included. No really effective 

 measure is, however, known. 



Any spot attacked and treated as above, should be visited 

 periodically to see whether surrounding plants have been 

 infected, and if so, the measures should be repeated. The 



