ILLUSTRATIONS 



PAGE 



1. Frost-crack in a maple 50 



2. Prost-crack healed over in summer 50 



3. Mistletoe growing on white fir 56 



4. Galls on branch of oak 63 



5. Polypore frujiting-body showing spores ..... 68 

 6: Shoe-string root-rot on pine 79 



7. Young toadstools of Armillaria mellea 80 



8. Mature fruiting-body of shoe-string root-rot fungus ... 81 



9. Ash rust 94 



10. Leaf-spot of basswood (by V. B. Stewart) .... 102 



11. FruitJng-body of i^ome* /omeretaTO* 106 



12. Beech wood decayed by Fames applanatus .... 109 



13. Frmting-hody oi Polyporus betulinus 114 



14. Leaf -blotch of horse chestnut 119 



15. Leaf-spot of butternut 123 



16. Brown felt-blight 131 



17. Endothia canker of chestnut 142 



18. Mycelial fans between bark and wood 143 



19. Spore-horns of chestnut canker fungus 145 



20. Perithecial stage of chestnut canker fungus . . . 146 



21. Leaf-spot of elm (by H..M. Fitzpatrick) . ... 152 



22. Powdery mildew of elm 153 



23. Pecky wood-rot, early stage 164 



24. Pecky wood-rot in Douglas fir 164 



25. Fruiting-body of Echinodontium tinctorium .... 167 



26. Brown heartwood-rot of Douglas fir 169 



27. Fruiting-bodies of Rkizina undulata (after Fitzpatrick) . . 178 



28. Cuboidal wood-rot of hemlock (by G. F. Atkinson) . . . 186 



29. Cedar-apple fungus on wild apple leaves (after Weimer) . . 194 



30. Cedar-apple fungus on haw leaf 195 



31. Cedar-apples, — early stages of development (after Weimer) . 197 



32. Cedar-apples in late autumn (after Weimer) .... 197 



33. Cedar-apple in spring with spore-horns (after Weimer) . .198 



xix 



