CONTENTS. ix. 



Clearings 49-51 



Forest Fires 51-54 



Forest Fire Statistics 54-55 



, Prevention and Control of Forest Fires 55-57 



The Lumber Industry 57 



Types of Saw Mills 57 



Progress of the Lumber Industry 58-66 



Diseases of Forest Trees and Wood-destroying Fungi 66 



Extent and General Results of Disease 66-67 



Some Dangers Surrounding Trees Enumerated . . . 67-68 



Protective Structure of Trees 68-69 



The Decay of Dead Wood 69 



Conditions That Favor Decay 69 



Conditions That Discourage Decay 70-71 



Conditions and Organisms That Induce Diseases of 



Trees and Decay of Wood 71-72 



Water in Its Relation to Tree Diseases 72 



Plant Food Supply in Its Relation to Tree Diseases 72-73 



Relation of Excessive Cold to Tree Diseases 73 



Diseases Induced by Storms 73-74 



Effects of Insufficient Light 74 



Injuries Due to Smoke and Gas 74 



* Effects of the Wounding of Trees by Mammals . . . 74-75 



Injuries by Forest Fires 75 



Injuries by Insects 75 



Injuries by Fungi 75 



Fungi and Their Methods of Work 75-77 



Fungi That Injure the Leaves of Trees 77-78 



Fungi That Injure Bark 78-79 



■ Fungi That Injure Roots 79 



Fungi That Injure the Wood of Living Trees . . . 79-80 



Fungi That Injure Dead Wood 80-81 



Studies of Fungi in West Virginia 81 



List of Fungi Destructive to Trees and Wood 82-86 



Injuries to Trees by the Mistletoe 86-87 



Insects That Injure Forests and Forest Products . . 87 



Nature and Extent of Injury 88-89 



Insects That Attack the Bark of Living Trees 89-91 



