

CONTENTS. 



Page. 



Introduction 9 



Environmental diseases 10 



Smoke and sulphur gases 10 



Unfavorable soil conditions 12 



Extreme cold l:> 



Injuries caused by animals, wind, etc 14 



Diseases caused by miscellaneous parasitic and saprophy tic organisms. 14 



Diseases caused by insects 14 



Diseases caused by parasitic higher plants 14 



Diseases caused by miscellaneous fungi 18 



Mildews 18 



Tar-spot 19 



Rusts 19 



Sycamore leaf-blight 20 



Leaf-spots r 20 



Leaf-blister fungi 21 



Nectria cinn/ibtirina 21 



Chestnut bark disease 22 



Root-rots 22 



Slime-flux diseases 24 



Diseases caused by wound fungi 25 



White heart-rot caused by Fomcs igniarius 25 



Nature of disease caused by Fomes igniarius 25 



Susceptibility of different hosts to the white heart-rot. ... 26 



Distribution of Fomes igniarius 27 



Description of the fungus 



Spread of the disease 29 



Influence of environment on prevalence of white heart-rot 31 



Ultimate fate of diseased trees 33 



Effect of the fungus on the wood structure 34 



Preventive measures 35 



Red heart-rot caused by Poly poms sulphwcus 37 



Piped-rot of oak and chestnut 39 



Soft rot of oaks caused by Polyporus obtusus 41 



Heart-rot caused by Fomes nigricans 42 



Disease caused by Hydnum erinaceus 44 



Black locust disease caused by Fomes rimosus 45 



White heart-rot of ash caused by Fomes fraxinophilus 46 



Red heart-rot of birch caused by Fomes fulrus 47 



Soft heart-rot of catalpa caused by Polystictus versicolor - 47 



Heart-rot of oaks caused by Fomes everhartii 48 



White-rot caused by Polyporus squamosus 48 



Two sap-rots -1" 



Decay caused by Fomes fomentarius 50 



Decay caused by Polyporus betulinus.. 51 



5 



149 



