Octoses, 31. [OE]nidin, 85, 116. [OE]nin, =85=. Oils, =129=. Oil of bergamot, 148. Oil of bitter almonds, 86, 148. Oil of cassia, 148. Oil of cinnamon, 148. Oil of garlic, 148. Oil of lavender, 148. Oil of mustard, 148. Olive oil, 130. Opium, 158. Organic acids, 18, =124=, 248. Organized ferments, 183. Ornamental pigments, =102=, 123. Ornithine, 169. Oryzenin, 176. Osazones, 40, 41, 49. Osmotic pressure, 213, 228. Osones, 41. Oxidases, 186, 190, 193. Oxime, 44. Oxycellulose, 73. Oxycumarin glucosides, 81. Oxygenated oils, =147=. Oxyhydroquinone, 95. Oxyproline, 169. Pæonidin, 85. Pæonin, =85=. Palm oil, 133. Papain, 189. Papaverine, 155, =158=. Para-dextran, 62. Para-isodextran, 62. Paralyzers, 196. Para-pectin, =70=. Parasites, 16. Peanut oil, =133=. Pectase, 71. Pectinase, 189. Pectins, 20, 31, 67, =70=. Pecto-celluloses, =74=. Pectose, 31, 70. Pelargonidin, 85, =116=. Pelargonin, =85=. Pentosans, 31, 67, 68, 72. Pentoses, 30, 162. Pepsin, 167. Peptids, =166=, 167, 176. Peptones, 176. Permeable membranes, 228. Peroxidases, 190. Persimmons, 100. Persuelose, 36. Phæophytin, 107, 108. Phaselin, 176. Phaseolin, 176. Phenol, 95. Phenol glucosides, =79=. Phenyl alanine, 168, =177=. Phenyl hydrazine, 40. Phlein, =62=. Phloretin, 79. Phloridzin, =79=. Phloroglucinol, 95. Phosphates, 7. Phosphatides, 141, =143=. Phosphoproteins, 175. Phosphorus, 3, 5, =7=. Photo-chemical action of light, 253, 257. Photolysis, 26. Photosynthesis, 7, 8, 18, 21, 22, =24=, 254. Phycoerythrin, 102, =115=. Phycophæin, 102, =115=. Phyllins, 106, 107. Phyllophyllin, 107. Phyllopyrrole, 109. Physiological adaptations, 252, =257=. Physiological use, =19=. Phytase, 189. Phytochlorin, 108. Phytorhodin, 108. Pigment glucosides, =82=. Pigments, 18, =102=, 224, 254. Pinene, 147. Piperidine, 154. Piperine, =155=. Plant amines, =151=, 152, 163. Plant food, =1=. Plant nucleic acids, =162=. Polybasic acids, 124. Polyhydric alcohols, 31. Polypeptides, 167. Polysaccharides, =59=. Polyterpenes, 147. Poppy wax, 140. Populin, =80=. Porphyrins, 108. Potassium, 3, 5, 8, 10, 13, 14. Primary amines, 152. Proenzymes, 198. Proinulase, 199. Proinvertase, 199. Prolamins, 175, 176. Proline, 169, 177. Prolipase, 199. Prooxidase, 199. Protamines, 175, 176. Proteans, 175. Proteases, 186, 189, =192=. Protective colloids, 209. Proteins, 7, 18, 20, 151, 162, 163, =164=, 224. Proteoses, 175. Protoplasm, 17, 26, 221. Prulaurasin, 87. Prunase, 87. Prunasin, 87. Ptomaines, 152. Purine, =159=. Purine bases, 151, =159=, 162. Purpurin, 83. Putrescine, 152. Pyrimidine, 161. Pyrimidine bases, =161=, 162. Pyrocatechol, 95. Pyrogallol, 95. Pyrogallol tannins, =97=. Pyroxylin, 73. Pyrrophyllin, 107. Pyrridine, 154. Pyrrolidine, 154.