148 ABMILLARIA MELLEA, 



frequent victim, and after that, according to my experience, 

 Sitka spruce, Weymouth pine, and Corsican pine. Larch is 

 not usually attacked till it is more than fifteen years old, 

 but is then frequently killed b}?^ the honey fungus. I have 

 also seen trees of deodar. Douglas fir, monkey puzzle, and 

 common spruce all killed by it, and probably no species of 

 conifer is immune from attack. Among broad-leafed trees, 

 oak, beech, chestnut, laburnum, and alder are not infrequently 

 destroyed, and T have found a street-planted elm and other 

 trees killed by it. Wagner (1899) has found the fungus on 

 twenty-nine species of broad-leaved trees in Germany, 

 including pear and apple, and in America ^ many fruit trees 

 are fatally attacked. It has generally been held that broad- 

 leafed trees do not succumb to the fungus unless previously 

 weakened in some way, but this is always difficult to prove. 

 Death does not follow on attack so quickly as in the case 

 of conifers, and the early symptoms of the disease may be 

 mistaken for inherent weakness in the trees. Certainly oaks 

 are attacked in Britain as much in the open as in woods, 

 and there can here be no question of suppression by other 

 trees. At the same time park trees are especially liable to 

 all types of root disease, as for instance beech by Fomes 

 ausfraUs and F. resinaceus. This is probably due to gi'azing 

 animals damaging the surface roots, and also to the inferior 

 quality of the subsoil in parks as compared with woods, for 

 reasons mentioned in the discussion on Fomes annosvs. 



Larch trees are not usually killed until many years after 

 infection. Tlic external signs of advanced attack are the 

 death and fall of the needles and generally a flow of resin 

 at the base of the trunk. If a portion of the bark is removed 

 from the tree at a point near the roots, thick white layers 

 of mycelium are disclosed, and on digging the soil away 

 from the roots rhizomoiphs are almost invariably found. 

 In woods which have an open canopy the toadstools of the 

 fungus may be found growing from the roots of the trees 

 for many years in succession before the trees show any 

 external symptoms of ill health. 



J Paniniel (lOlI), Hm.,.- ( I<»I2 iuitl l!»14). TTcy ( litll). Lonjj; (IHH). 



