XX ILLUSTRATIONS 



PAGE 



34. Fruiting-bodies of Fames roseus 205 



35. Fruiting-body of Fames rimasus 220 



36. Tar leaf-spot of maple 224 



37. Leaf-spot of maple caused by Phyllasticta minima . . . 226 



38. Leaf-spot of maple caused by Glwosporium apacryptum (by H. M. 



Ktzpatrick) 227 



39. Leaf-blight of maple 228 



40. Nectria canker on maple 229 



41. Sections through Nectria canker on maple .... 230 



42. Sections through trunk of maple affected by wilt . . . 231 



43. Section through fruiting-body of Hydnum septentrioncde . . 235 



44. Leaf-blight of oak 238 



45. Leaf-blister of oak (by H. H. Whetzel) 239 



46. Powdery mildew on oak leaf (by G. F. Atkinson) . . . 242 



47. Twig-canker on oak 244 



48. Brown checked wood-rot in oak (by G. F. Atkinson) . . 248 



49. Fruiting-bodies of Polyporus svlphureus .... 249 



50. Fruiting-body of Polyporus Berkeleyi 253 



51. Fruiting-body of Polyporus dryadeus 262 



52. Blister-rust on twig of white pine (after Hesler and Whetzel) 276 



53. Blister-rust on trunk of white pine 277 



54. Uredinial stage of Cronartium ribieola on currant (after Hesler and 



Whetzel) 278 



65. Telial stage of Cronartium ribieola on currant (after Hesler and 



Whetzel) . . . . ; 278 



56. Blister-rust on lodgepole pine 286 



57. Limb-galls on poplar 304 



58. Common ■white wood-rot (after Hesler and Whetzel) . . 306 



59. Fruiting-body of Fames igniarius 307 



60. Fruiting-body of Fames igniarius (form called Fames nigricans) 308 



61. Section through fruiting-body of ii'ome* tjrreianiis . . . 309 



62. Witches'-broom on black spruce 322 



63. Mistletoe witches'-brooms on black spruce .... 323 



64. Pecky wood-rot in spruce 325 



65. Pecky wood-rot, advanced stage 326 



66. Leaf-blight of sycamore 334 



67. Sycamore tree defoliated by leaf-blight fungus (by M. F. Barrus) 325 



68. Cankers on small sycamore twigs 336 



69. Cankers on limbs of sycamore 337' 



70. Powdery mildew on willow leaves (by G. F. Atkinson) . . 342 



