440 



INDEX 



Opium Vn-ppY [Pii paver soiiiiiif cm III), 



6i, 155- 

 Optical section, 6 (fig.), 401. 

 Orange (Citrus aurantium), 62, 151 ; 



polyembryony of, 371 (fig.), 



372, 390. 

 Orchids (Orchidacecs), 355 ; aerial 



roots of, 73-5 (fig.) ; pollen of, 



361. 

 Orchis morio, pollen of, 362 (fig.). 

 Oregon Pine (Pseudotsnga douglasii), 



129. 

 Organic acids, 60. 

 Organic material, absorption of, by 



Fungi, 230. 232, 236, 237, 259 ; 



by insectivorous plants, 149, 



150; by mycorrhiza, 72, 232; 



by parasitic Angiosperms, 179. 

 Origin of new species, 378, 380, 381, 



382, 393- 

 Orthotropous ovules, 358 (fig.). 

 Oryza saliva, 4^, 53, 257 ; starch of, 



42 (fig.), 43. 



Osazones, 47 (fig.). 



Oscillatoria, 205. 



Osmic acid, and fats, 49. 



Osmometers, 402, 403. 



Osmosis, 8. 



Osmotic pressure, 8, 10 ; deter- 

 mination of, 10, II, 12, 15 ; of 

 different strengths of sea-water, 

 402, 403 ; of .guard-cells, 100 ; 

 of food-reserves, 11, 44, 45 ; 

 role of, in growth of plant-cells, 

 26. 



O&iintnda rcgalis, habit of, 289, 309 

 (tig.) ; prothallus of, 304 ; 

 sporangia of, 300, 309 (fig.). 



Osterhout, 13. 402. 



Ovary (of Angiosperms), 334, 354-G, 



364. 365. 



Ovules of, Angiosperms, 354, ^56, 

 357-9 (figs.), 365, 306 (fig.) ; 

 Conifers, 334, 336, 347 (fig.), 

 348, 349 (fig.) ; Cycads, 324, 

 325 (fig.) ; Lygiiioptcris. 328, 

 330, 331 ; parasites, 179, 

 365. 



Ovuliferous scale (of Conifers), 347 



(fig.). 348, 352 (fig.). 353. 

 Ovum. See Egg. 

 Oxalate of lime, 58, 59, 130, 237 ; 



reactions of, 59. 

 Oxalic acid, 58. 

 Oxidases (oxidising enzymes), 55, 



155. 

 Oxygen and Bacteria, 263 ; and 

 protoplasmic movement, 4. 



Pieony {PcEoiiia), 8. 



Pateozoic period, plants oi, 311. 



Pahsade tissue, 38 (fig.), 107, 108 

 (fig.), 109, 110, 161 (fig.); arm 

 — , no, III ; function of, 107, 

 109 ; of Alpines, 170 ; of 

 centric leaves, 116, 166; of 

 stems, 167 ; of sun- and shade- 

 leaves. 169 (fig.) ; of Taxns- 

 leaf, 342 (fig.). 



Palmella-stage of, Chlamydoinonas, 

 182 (fig), 184; Uloihrix, 214, 



215 (fig). 

 Palmitic acid, 49. 

 Palms, 44, 117. 



Papaver somniferuin . 61, 153. 

 Papaveraccae, 133, 154. 

 Paper, 35, 129. 

 Papilla;, 103, 148, 342 (fig.) ; stig- 



matic, 336, 364. 

 Para-rubber {Hcvea brasiliciisis), 



156. 157.. 



Parallel venation, 112. 



Parasites, protection again.st, 138, 

 142, 



Parasitic Angiosperms, 178 (fig.), 

 179. 231, 365, 372 ; Bacteria, 

 263; Fungi, 220 et seq., 252-5. 



Parasitism, 231, 247, 248, 252, 239, 

 264, 2S1, 288, 372 ; and im- 

 munity, 233. 



Parenchyma, 27, 33. 69. 



Parenchyma-sheath, 112, X13. 



Parenchymatous cells, 27, ^2, 65, 

 76. 



Parietal placentation, 356. 



Parmelia physodes, 258 (fig.). 



Passage-cells of, endodermis, 70 

 (fig.), 71, 75 (fig.) ; cxodermis, 

 57, 74. 75 (fig.). 



Passive hydathodes, 148. 



Pathogenic Bacteria, 263, 2 04. 



Pea (Pisuiii), 336. 370 ; hybrids of, 

 383, 384, 380; mutation in, 

 381 (lig.) ; protein of, 30, 52 : 

 root of, 72. 74 ; starch of, 42 



(fig.). 

 Pea-mildew (Erysiphc polygoiii), 243. 

 Pea-nut [Arachis hypogcsa), 40, 33. 

 Pear (Pyrus), 60 ; stone-cells of, 



30 (figs.), 32, 33. 

 Pe.'tic substances, 31, 

 Pectose, 231. 



Pediaslrmn, 191 (fig.), 192. 

 Pelargonium, hairs of, 105. 

 Pellia, 407 ; anatomy of, 272, 278 



(fig.) ; antheridia of, 277, 278 



(fig.) ; archegonia of, 2S0, 281 



