Fertilisation, 71. Field-mice, 164. Figs, 113. Finger and toe, 114, 127, 163. Fire, 240. Flaming, 164. Flattened roots, 246, 252. Fleshiness, 228. Flies, 86, 110, 142, 143, 145. Flux, 227, 231. Flying foxes, 244. Focussing of solar rays, 192. Foliage, 110. _Fontaria_, 134. Food, 18. Forest-fires, 241. Formic-aldehyde, 20. Foul products, 100. Foxy leaves, 191. Freezing, 121, 183. Frit fly, 182. Frost, 153, 160, 225, 229, 248, 249. Frost-beds, 243. Frost-blisters, 212, 218. Frost canker, 222. Frost-cracks, 204, 209, 242. Frost-patches, 240. Frost-ridge, 209. _Fumago_, 190, 232. Fumes, 104. Functions of roots, 43, 45. Functional depression, 96. Fungi, 89, 108, 143, 174, 189, 200, 205, 207, 208, 212, 216, 219, 223, 229, 231, 233, 238, 240, 241, 243, 248, 251, 255, 258, 265, 267, 283, 284, 288. Fungus attacks, 139. Fungus galls, 219. _Fusarium_, 143, 238. _Fusicladium_, 189. _Fusisporium_, 237. _Gagea_, 258. Gall-apple, 218. Gall-flies, 219. Gall-insect, 139. Gall-like swellings, 128. Galls, 86, 110, 120, 130, 138, 212, 214, 218, 255. Gangrene, 231. _Garreya_, 264. Gas, 160. Gases in soil, 104. _Gastropacha_, 225. Gelatine, 163. General death, 116. General disease, 119, 120. Germ-plasm, 267. _Gesneria_, 260. _Glechoma_, 218. _Gloeosporium_, 189, 190, 208. _Gloxinia_, 260. Goats, 164. Gooseberry, 217. Graft-hybrids, 262, 267, 271, 283. Grafting, 78, 155, 169, 183, 250, 262, 271, 281. Grain-rust, 146. Grapes, 192, 230, 231. _Grapholitha_, 109, 207. Grass, 111, 189, 190, 205, 218, 233. Green fly, 161. Grew, 85. Greyish spots, 187. Growth, 271, 274, 275, 286. Grubs, 110, 207. Gumming, 235. Gummosis, 227, 234, 235. _Gymnosporangium_, 114, 176, 223. Hail, 106, 240, 241. Hales, 85. _Haltica_, 209. Hardy varieties, 168, 170, 177. Haustoria, 134, 135, 136. Healing, 194, 196. Healing by cork, 123. Health, 272, 287. Health and disease, 91, 97, 287. Heliotropism, 126. _Hemileia_, 146, 169. Heredity, 72, 283. _Herpotrichia_, 135, 190. Hessian Fly, 182. _Heterodora_, 219, 220. _Hieracium_, 112. History of Phytopathology, 85. Holdfast of roots, 42. Hollyhock disease, 143. Holly, 217. Honey dew, 144, 227, 232, 233. Hops, 162, 187, 191, 232, 253. Hop-aphis, 146. Hop-disease, 166. Hop mildew, 161. _Hormomyia_, 219. Hornbeam, 224, 233, 242. Horse-radish, 260. Host, 284, 285. Hyacinth, 231, 261. Hyacinth disease, 143. Hybrids, 69, 156, 281. Hybridisation, 69, 75, 169, 266, 281. Hydrochloric acid, 181. Hydrogen, 272. Hymenomycetes, 206. Hypertrophy, 119, 127, 139, 213, 215, 247, 266. _Hypochaeris_, 112. _Hypomyces_, 237. _Hyponomeuta_, 254. Ice, 184, 209. Ichneumon-flies, 165. _Icterus_, 181.