_Phyllachora_, 189. _Phyllereum_, 253. _Phyllobium_, 217. _Phyllosiphon_, 188. _Phyllosticta_, 188, 209. _Phylloxera_, 110, 145, 149, 154, 155, 163, 166, 172, 188, 219, 220, 268. Physiology, 1, 66, 85. Physiological diseases, 119, 121. _Phytomyza_, 206. Phytopathology, 85. _Phytophthora_, 115, 136, 144, 150, 151, 235, 236. _Phytophysa_, 219. _Phytoptus_, 189, 213, 214, 215, 218, 219, 253, 254. _Pilea_, 219. _Pilobolus_, 126, 140. Pines, 183, 223, 234, 251, 252. Pine-apple, 258. Pith flecks, 204, 207. Plant as agent of disease, 99, 108. Plant, agricultural chemistry of, 1. Plant and its food, 7. Plant and its surroundings, 1. Plant, a machine, 1, 15. Plant, central object of study, 1. Plant, physiology, 1. _Plantago_, 257. Plantain, 112, 257. Plants, dying out of, 93. Plasmodia, 163. _Plasmodiophora_, 114, 126, 127, 144, 163, 219, 284, 285. Plasmolysis, 47. _Pleospora_, 236. _Pleotrachelus_, 126, 140. Plum, 171, 189, 192, 209, 214, 206, 231, 235, 248, 249, 260. _Poa_, 258. Pocket-like galls, 155, 214, 218. Pocket-plums, 214. Pockets, 253. Poison, 102, 130, 136, 163, 216. Poisonous gases, 181, 248. Pollen grain, 288. Pollination, 248, 262, 265, 266, 271. _Polydesmus_, 236. _Polygonatum_, 175. _Polygonum_, 258. Polymorphism, 174. Polyporei, 142. _Polyporus_, 143, 206. _Polystigma_, 189. Poplar, 188, 206, 215, 218, 254. Post and epidemics, 142. Potassium, 272. Potassium sulphite, 162. Potato, 162, 171, 194, 209, 216, 236, 237, 258. Potato-disease, 114, 143, 149, 150, 166, 189, 207, 235. Powders, antiseptic, 159, 160, 161. Predisposition to disease, 98, 99, 105, 168, 169, 229, 262, 268, 277, 278, 282. Preventible diseases, 159. Preventitious buds, 259. Prolepsis, 257, 259. Proliferations, 257, 258. Properties of soil, 57. Prophylactic measures, 160. Proteids, 132, 138, 272, 277, 286. Proteolytic enzymes, 132. _Protomyces_, 217. Protoplasmic molecules, 276, 278, 286. Protoplasm, 33, 41, 271, 272, 274, 276. Pruning, 105, 143, 194, 225, 250. Prussic acid, 163, 165, 173. _Psylla_, 253. _Puccinia_, 88, 114, 169, 175, 176, 188, 189, 247, 252. Puckers, 214, 235, 246, 253. Puffing of spores, 142, 144. Punctures, 212. Pure culture, 166. Purple-black spots, 191. Pustules, 188, 190, 212, 217. Putrefaction, 234. _Pyrethrum_, 161. _Pyrus_, 214. _Pythium_, 114, 119, 136, 144, 160, 230. _Quassia_, 161. Quinine, 173. Rabbits, 108, 142, 164, 194. Rain trees, 233. Rankness, 97, 227, 228. Rats, 108, 163. Rays of light, 18. Red light, 21. Red spider, 161, 187, 188, 192. Red spots, 188, 253. References in Bible, 85. Remedial measures, 89. Repellent substances, 136. Reproduction, 72, 281. Reserves, 274. Resin, 125. Resin-flux, 234. Resinosis, 227, 234.