i. 397

Ophrys, fly, structure and mode of reproduction of, i. 396

Opium, alkaloids obtained from, i. 427 almost universal use of, in the East, i. 427

Orange, amount of radiant heat absorbed by the perfume of, i. 44 fructification of the, i. 381

Oranges, fungus of decayed, i. 290

Orbitolite, characters of the, ii. 33 a fossil gigantic one found in Canada, ii. 54

Orbitolites complanatus, structure of, ii. 33, 34 development and varieties of, ii. 35, 36 habitat of, ii. 36

Orchids, their structure, habitat, and mode of reproduction, i. 388-403 theoretical structure of, i. 403

Orchil, whence obtained, i. 303 from what obtained, i. 124

Orchis mascula, structure and mode of reproduction of, i. 389, _et seq._

Orchis pyramidalis, structure and mode of reproduction of, i. 393, _et seq._

Oscillatoria littoralis, structure and motions of, i. 213

Oscillatoria spiralis, motions of, i. 213

Oscillatoriæ, structure, habitat, and motions of, i. 213 reproduction of, i. 214

Osmunda regalis, structure and habitat of, i. 363

Osmundineæ, characters of, i. 363 sporangia of, i. 343 characters of the group, i. 345

Ostrapods, characters of the, ii. 207

Otolites of Gastropoda, ii. 236

Otolites of Thaumantias, ii. 93

Ovulata, siliceous skeleton of, ii. 60

Oxalic acid, former and present modes of making, i. 116 produced by lichens, i. 303 synthetical formation of, i. 424

Oxygen, i. 6-11 effect of the combination of the atoms of oxygen and carbon in combustion, i. 30 absorptive power of ozonized oxygen, i. 43 absorptive power of, i. 39, 41 proportion of oxygen to hydrogen in the composition of water, i. 94 limit to the number of combustions of, with nitrogen, i. 95 weight of the atoms of, in the peroxide of manganese, i. 99 weight of the atoms of, compared with those of hydrogen, i. 99, 100 spectrum analysis of, i. 139 inhalation and exhalation of, by plants, i. 416, 417

Oysters, iodine found in, i. 19

Ozone, i. 7 effect of the combination of ozone and oxygen in the absorption of radiant heat, i. 43 Prof. Tyndall’s conjecture as to the production of ozone, i. 44 its affinity for iodine, i. 96 its possible effect on the solar spectrum, i. 132 production of, i. 17

P

Padina Pavonia, or Peacock’s tail laver, structure of, i. 247

Pagurus, or hermit crab, structure and mode of reproduction of, ii. 197

Palm, stem or axis of a, i. 384 growth and reproduction of palms, i. 384, 385

Palmoglœa macrococca, structure and development of, i. 182

Palmyra palm, growth of the stem of, i. 385

Pandanus or screw pine, roots and habitat of, i. 387

Papillaris, siliceous skeleton of, ii. 60

Paraffin, i. 105 crystals of, how produced, i. 127

Paraffin oil and candles, i. 119, 127

Paramœcium caudatum, cilia and mouth of, ii. 68, 69 immense propagation of, ii. 74

Parkeriaceæ, or Ceratopteridineæ, structure and habitat of, i. 363

Parmelia saxatilis, structure and habitat of, i. 305

Parmeliacei, structure of the, i. 302 characters of the group, i. 304

Parmelia parcolerina, yellow dye obtained from the, i. 124

Parmelia parietina, dye obtained from, i. 303

Passalus cornutus, parasitic fungus in the stomach of, i. 274

Patchouli, amount of radiant heat absorbed by the perfume of, i. 44

Patellidæ, or limpets, structure, food, and habitat of, ii. 238, 239

Paulia perforata, organs of reproduction of, i. 301

Pea mildew, fungus producing the, i. 295

Peach, cause of blistered leaves of the, i. 291

Pear, cause of blistered leaves of the, i. 291

Pearl oyster, nacreous lining of shell of, ii. 234

Pease, caseine obtained from, i. 125

Peat, and peat mosses, i. 333

Pecten, or scallop, eyes of the, ii. 235

Pediastrum, structure and development of, i. 194

Pedicellaria globosa, structure of, ii. 180

Pelagia, structure and mode of reproduction of, ii. 97

Peltigeri, characters of the group, i. 305

Peneroplis, structure of, ii. 31, 32

Penicillia mould, structure of the, i. 285

Penicillium armeniacum, spores of, i. 285, 286

Penicillium candidum, production of, i. 287

Penicillium glaucum, structure and habitat of, i. 286, 287 its polymorphous character, i. 287 in the yeast of beer, i. 288 its production of acetic fermentation, i. 288

Pennatula phosphorea, structure and habitat of, ii. 128 modes of reproduction of, ii. 129

Pennatulidæ, or sea-pens, structure, habitat, and mode of reproduction of, ii. 128, 129

Pentacrinites, structure of, ii. 175

Pentacrinus caput-Medusæ, structure and habitat of, ii. 175

Pentacrinus Europæus, structure of, and change to a comatula, ii. 176

Peppermint, absorption of radiant heat by the perfume of, i. 44

Peranemeæ, or Woodsieæ, characters of the group, i. 350

Perfumes of flowers and plants, absorption of radiant heat by the, i. 44 weight of the perfumes, i. 45 chemical combinations forming, i. 97

Peridinium, structure and habitat of, ii. 72 scarlet colour it gives to the sea, ii. 72, 75 mode of propagation of, ii. 75

Perisporacei, structure and habitat of, i. 295

Periwinkle, tongue of, ii. 239

Peronospora infestans, its destruction of the potato, i. 284 structure and mode of working, i. 284, 285 its effects on the branches and wood of trees, i. 285

Perophora Listeri, structure, habitat, and development of, ii. 222, 223 larva of, ii. 224

Petroleum, enormous quantities of, in North America, i. 126 the Babylonian petroleum fountains of Is, i. 126 geological formation in which it occurs, i. 126 dangers of petroleum wells, i. 127 substances yielded by it on destructive distillation, i. 127

Peyssonnelia, habitat of, i. 237

Peziza aurantia, cells of staff-shaped particles of, i. 291

Peziza elegans, beauty and habitat of, i. 291

Peziza vesiculosa, force of its ejection of its sporidia, i. 292

Pezizæ, structure and habitat of the genus, i. 290, 291 fructification of, i. 291 eel-shaped particles or antherozoids of, i. 292 force with which many of them eject their sporidia, i. 292

Phacopsis, organs of reproduction of, i. 307

Phalloidei, structure of, i. 268

Phallus Mokusin, a food of the Chinese, i. 268

Phascei, characters of, i. 329

Phenic acid, i. 123

Phenyle, chemical composition of, i. 128

Philomedusa Vogtii, a parasite of the medusæ, ii. 100

Phonolite stone, on the Rhine, of what it consists, i. 206

Phosphorescence, property of, i. 66 of insects, fish, and plants, i. 67 of inorganic substances, i. 67 essential difference between phosphorescence and fluorescence, i. 67, 68

Phosphorescent light of luminous fungi, i. 264 causes of this, i. 264

Phosphorus, i. 17 whence procured, i. 17 red allotropic, i. 17 takes fire spontaneously in chlorine gas, i. 19 atomic weight of, compared with that of hydrogen, i. 100

Photography, importance of the magnesium light in, i. 154

Phyllodoce, structure of, ii. 157

Phyllopoda, characters of the order, ii. 209

Physalia, or ‘Spanish man-of-war,’ structure, and modes of locomotion and reproduction of, ii. 111-114

Physaliidæ, characters of the order, ii. 111

Physomycetes, characters of the order, i. 296

Physophora hydrostatica, structure and habitat of, ii. 109, 110

Physophoridæ, characters of the family of the, ii. 109-111

Pillwort, structure and habitat of, i. 371, 372

Pilularia globulifera, or pillwort, structure and habitat of, i. 371

Pilularia minuta, structure of, i. 371

Pinna, structure of the shell of, ii. 233

Pitch, manufacture of, i. 120

Planets, spectra of the, i. 157, 158, 161, 162

Plants, absorption of radiant heat by the perfumes of, i. 44 weight of the perfumes, i. 45 phosphorescence of, i. 67 their synthetic process of rearing their fabrics, i. 96 this process imitated by artificial means, i. 96 chemical nature of the colouring matter of, i. 428, 429

Platinum, properties of, i. 5 how vaporized, i. 30 effect of electricity on, i. 32 crystals of, formed artificially by electricity, i. 74 its resistance to electricity, i. 90

Pleurocarpi, characters and habitat of the group, i. 328

Pleurosigma angulatum, structure of, i. 198, 199

Plumbago, or natural graphite, little or no porosity of, i. 112

Podocyrtis Schomburgi, structure and habitat of, ii. 20, 21 fossil and existing species of, ii. 20

Poisons, vegetable, i. 425, 426

Polarization of light and heat, i. 68, 69 relation of polarization of light and heat to crystallization, i. 70, 71

Pollen of flowering plants, i. 379

Polyatomic theory, the, i. 107

Polycystina, structure and habitat of the, ii. 19, 20

Polygastria, a name for the Infusoria, ii. 71

Polyides rotundus, mode of reproduction of, i. 229 structure and mode of propagation of, i. 237, 238

Polynoë, structure of, ii. 160

Polypary of the Alcyon zoophytes, ii. 123

Polypes. _See_ Hydrozoa

Polypodiaceæ, characters of the order, i. 344 sporangia of, i. 343

Polypodineæ, characters of the group, i. 344 habitat of the, i. 345

Polypodium, structure and habitat of the genus, i. 345 vulgare, fronds of, i. 340, 345 sori of, i. 342, 345 structure of, i. 345

Polyporei, structure, habitat, and growth of, i. 264, 265

Polysiphonia, structure of the genus, i. 233

Polysiphonia elongata, structure and mode of propagation of, i. 234

Polystichum, characters of the genus, i. 347 sorus and indusium of, i. 347

Polystichum aculeatum, characters of, i. 348

Polystichum angulare, characters of, i. 348

Polystichum Lonchitis, structure of, i. 347

Polystichum proliferum, organs of reproduction of, i. 348

Polystomella, characters of the genus, ii. 47

Polystomella crispa, form of, ii. 28 structure and habitat of, ii. 47, 48 cristata, form of, ii. 28 striato-punctata, habitat of the, ii. 48

Polytrichei, characters of the tribe, i. 329

Polytrichum commune, organs of fructification of, i. 325

Polytrichum dendroides, structure of, i. 329

Polyzoa, or Bryozoa, characters of, ii. 218

Polyzonia cuneifolia, structure of, i. 242, 243

Porites, or reef-building corals, ii. 140

Porphyra laciniata, structure and habitat of, i. 227

Porphyra vulgaris, structure, habitat, and mode of reproduction of, i. 227

Porpita, characters of the genus, ii. 117 glandifera, structure, habitat, and mode of reproduction of, ii. 117, 118

Potash, caustic, effect of the heating of, by an electric discharge, i. 84 its effect on electricity in a vacuum tube, i. 86 cyanate of, combination forming, i. 106 nitrate of, its opacity to the invisible rays, i. 65 oxalate of, formation of, i. 117 violet coloured light obtained by the combustion of, i. 133 in the land plants, i. 414

Potassium, i. 3 affinity for oxygen, i. 96 atomic weight of, compared with that of hydrogen, i. 100 one of an isomeric triad with cæsium and rubidium, i. 105 iodide of, whence obtained, i. 19

Potato, fungi causing the murrain in the, i. 284, 285 mode in which the injury is done, i. 284 poisonous nature of the leaves and berries of the, i. 426, 427

Poulpe, structure of the, ii. 245

Praya diphys, structure and mode of reproduction of, ii. 103-106

Propagation of diatoms by bisection, by conjugation, and by gonidia, i. 200

Protein produced by plants, i. 419

Protococcus pluvialis, structure and development of, i. 184 cycles of reproduction, i. 186

Protococcus viridis, abundance of, found in dust from Egypt, ii. 65

Protophytes, structure and development of, i. 182

Protoplasm of plants, structure and function of, i. 412, 413

Protozoa, structure of the, ii. 13

Pterideæ, characters of the group, i. 357

Pteris, characters of the genus, i. 357

Pteris aquilina, stems of, i. 339 or bracken, structure, mode of reproduction, and habitat of, i. 357, 358

Pteris esculenta of New Zealand, i. 358

Pteris serrulata, development of spores of, i. 337 antheridium and spermatozoids of, i. 338

Pteris serrulata: archegonium of, i. 338

Pucciniæ, structure and habitat of the sub-order, i. 276, 277

Puccinia Amorphæ, spores of, i. 276

Puccinia Fabæ, structure, habitat, and method of reproduction of, i. 280 alternation of generations of, i. 280

Puccinia Graminis, spore-cases of, i. 280

Puccinia lateripes, spores of, i. 276

Puff-balls of the meadows, i. 267

Purple dyes, i. 123, 124

Pycnogonoïdea, or spider crabs, structure and habitat of, ii. 211

Pyrosomidæ, structure and mode of reproduction of the, ii. 225

Pyxinei, characters of the, i. 307

Q

Quartz, rock-crystal the purest form of, i. 17 certain thickness of, not transparent to invisible rays of light, i. 65 axis of symmetry of, i. 72 aqueous solution of, i. 110 characteristics of the, i. 111

Queen conch, shell of, ii. 234

Quinine, structure of, and whence obtained, i. 427

Quinqueloculina Bronniana, form of, ii. 228

R

Radiation of light and heat, i. 34, 35 effects of, i. 35, 36 generally independent of colour, i. 36 Professor Tyndall’s experiments, i. 38 experiments showing radiation to be equal to absorption, i. 46 dynamic radiation, i. 49 absorption a phenomenon irrespective of aggregation, i. 53

Radicles, compound, i. 106

Ramalina calicaris, gluten of, i. 303

Ramalina polymorphum, dyes obtained from, i. 303

Ramalina scopulorum, dyes of, i. 303

Raphides, structure and formation of, i. 424, 425

Red Sea, foraminifera in the, ii. 51

Reed, Cordyceps on the ergot of the, i. 293

Reed, Italian, vegetable tissues represented in, i. 175, 176

Reef-building corals, ii. 138-142

Reefs, barrier, formation of, ii. 143

Resins, formation of, i. 422

Respiration, chemical powers causing, ii. 4

Respiration of the muscles, ii. 8

Reticularia, characters of the order, ii. 24

Reticularia maxima of cucumber beds, i. 269

Rhabdonia Coulteri, mode of propagation of, i. 236

Rhamnus cathartica, M. Charwin’s discovery of a green dye obtained from the, i. 124

Rhizocrinus Lofotensis, structure of, ii. 175

Rhizopoda, structure of the, ii. 13 simple Rhizopods, forms of, ii. 22

Rhizoselenia, enormous masses of, in the Indian Ocean, i. 205

Rhizospermæ. _See_ Marsileaceæ

Rhizostoma, or many-mouthed medusæ, structure and mode of reproduction of, ii. 97, 98 food of, ii. 98

Rhodomelaceæ, structure &c. of, i. 241

Rhodospermeæ, characters of the, i. 180 structure and mode of reproduction of, i. 227, _et seq._ causes which affect the form and limits of, i. 243

Rhodymenia palmata, structure and mode of reproduction of, i. 236

Rhodymeniaceæ, structure of, i. 236

Ricciaceæ, or Crystalworts, characters of the order, i. 316

Richmond, in Virginia, siliceous deposit upon which it stands, i. 206

Riella, characters of the genus, i. 316, 317

Rivularia, structure of the genus, i. 213, 215

Rivularia nitida, structure and motions of, i. 213, 215

Rocella fuciformis, dye and orchil obtained from, i. 303

Rocella tinctoria and fusiformis, blue and purple dyes obtained from,