CONTENTS. 



Page. 



Scope of the study 7 



Structure of the tree 8 



Normal functions of the tree 9 



Disease a disturbance of normal functions 11 



Causes of disease 12 



Examination of diseased trees 17 



Symptoms of disease 18 



Fungi 24 



Nature and development 24 



Fungi with fruiting bodies in the form of stools or crusts. 29 



Porous fungi 29 



Spiny fungi 29 



Gill-bearing fungi ' 30 



Fungi with fruiting bodies not in the form of stools or 



crusts 30 



Leaf and twig fungi 30 



Attack on vital and non vital parts of the tree 30 



Fungi which attack vital parts of the tree 30 



Fungi which attack nonvital parts of the tree 31 



Diseases of foliage, twigs, and branches 32 



Effect 32 



Needle disease of white and red fir 33 



Tar-spot fungus 33 



Needle fungus of lodgepole pine 33 



Needle disease of yellow pine 34 



Stunting needle fungus of yellow and Jeffrey pine 34 



Yellow witches' brooms of white and red fir 35 



Incense cedar rust 35 



Blue witches' brooms of sugar pine 37 



Tip-dying of white and Douglas fir , 37 



Black cobweb fungi 38 



Pine gall fungus 38 



3 



