LIST OF ILLUSTRATIONS xi 



FIG. 



62. Hy menial layer of Armillaria mellea .... page. 150 



63. Rhizomorphs of Armillaria mellea between bark and 



wood of larch stem ... . . . . facing page 150 



64. Small portion of Fig. 63 enlarged .... . . 150 



65. Section of larch stem attacked by Armillaria mellea . 155 



66. Hollow larch stem rotted by Polyporus sulphureus . ,, 155 



67. Armillaria mellea. Radial longitudinal section of 



larch wood showing 'black line' . page 155 



68. ,, Transverse section of larch wood 



showing ' black line ' . . 157 



69. 70. Living larch-trees with honey fungus growing from 



their roots facing page 166 



71. Diagram showing life-cycle of heteroecious rust . . . page 174 



72. Melampsoridium fyetulinum ..... facing page 175 



73. Sporangiophore of Phytophthora omnivora and coni- 



diophore of Fiwoma parasiticum ..... page 180 



