Chapter XXXVI: Appendix: E

COMPARISON BETWEEN THE CENTIGRADE AND FAHRENHEIT THERMOMETERS.

F. C.
212 100
200 93.3
150 65.6
112 44.4
110 43.3
108 42.2
106 41.1
105 40.5
104 40
103 39.4
102 38.9
101 38.3
100 37.8
99 37.2
98 36.7
96 35.6
94 34.4
92 33.3
90 32.2
88 31.1
86 30
84 28.9
82 27.8
80 26.7
78 25.6
76 24.4
74 23.3
72 22.2
70 21.1
68 20
66 18.9
64 17.8
62 16.7
60 15.6
58 14.4
56 13.3
54 12.2
52 11.1
32 0
25 -3.9

INDEX.

Abbé on microscopical vision, 37

Abbé’s apertometer, 59

---- condenser, 176

---- stereoscopic eye-pieces, 64

---- test-plate, 164

Aberration, chromatic, 25

---- of the eye, chromatic, 33

---- spherical, 23

Abraxas grossulariata, 598

Absolute alcohol as a hardening reagent, 287

Acaras domesticus, 625

Accessories of the microscope, 197

Achromatic condenser, Beck’s, 180

---- ---- Gillett’s, 173

---- ---- method of using, 190

---- ---- Powell’s, 178

---- ---- Ross’s, 176

---- ---- Smith & Beck’s, 173

---- ---- Watson’s, 177

Achromatic objective, the, 152

Acineta, 495

Actiniæ, 527

Actinophrys-sol, 489

Adams’s book on the microscope, 8

Adipose tissue, 644

Ædogoniaceæ, 409

Aerobic spores, 399

Agar-agar, to prepare nutrient, 330

Air bubbles, 348

Alcyonella, 534

Algæ, 399

---- media for preserving, 343

---- red, 413

Alvarez’s discovery of bacillus, 392

Amici prism, the, 190

Amœba, 480

Amphibian changes, 669

Amphistoma, 570

Amyot finder, the, 205

Anacharis alsinastrum, 419

Anemones, sea, 526

Angle of vision, 72

Anguillula, 567

Animal structures, staining, 292

Annulosa, 562

Antennæ of insects, 584

Antenna of silkworm moth, 605

Anthrax bacillus, 369

Anthrozoa, 523

Apertometer, Abbé’s, 59

Aperture, definition of, 45

---- measurement of, 57

---- numerical, 57

---- table, 58

Aphides, 587

Aphrophora bifasciata, 618

Apis mellifica, 598

Aplysiidæ, 549

---- dipilans, 549

Apparatus for mounting, 352

Appendices, 673

Arachnidæ, 618

Aragonite, 232

Arcella, 483

Arenicola, 577

Argyroneta aquatica, 621

Artemiæ, 581

Arteries, 622

Artery-needle, 303

Arthropoda, 583

Arthrospores, 366

Ascidian, 669

Astroides calyculcaris, 529

Babè’s method of staining bacteria, 334

Bacillus, anthrax, 369

---- of plague, 372

---- ---- in rat’s blood, 372

---- splenic fever, 369

---- typhoid, 370

Bacteria, 317

---- aerobic, 399

---- classification of, 373

---- Cohn on multiplication of, 367

---- cultivation of, 327

---- ---- in tubes, 331

---- ---- on plates, 331

---- faculties of, 373

---- in butter, 393

---- in cheese, 393

---- in milk, 393

---- in sections of tissue, 337

---- invasion of potato-tubers by, 398

---- microscopical examination of, 333

---- phosphorescent, 373

---- reproduction of, 365

---- size of, 365

---- staining, 334

---- Winogradsky’s investigations of, 398

Bacterial action in tanning skins, 393

---- fermentations, 391

Bacteriological investigations, apparatus for, 318

---- ---- mounting media, 320

---- ---- reagents used, 320

---- microscope, the, 135

Bacteriology of the dairy, 393

Baker’s advanced student’s microscope, 123

---- collecting stick, 350

---- histological microscope, 125

---- micro-photographic apparatus, 217

---- microscope lamp, 191

---- microscopes, 120

---- Nelson condenser, 184

---- ---- model microscope, 120

---- objectives, 168

---- student’s condenser, 184

Baird, Dr., on daphnia, 581

Barnacle, 539

Bartley’s warm-stage, 281

Batrachospermæ, 409

Beck’s binocular dissecting microscope, 101

---- ---- National microscope, 99

---- complete microscope lamp, 202

---- compressor, 275

---- disc-holder, 198

---- large Continental model microscope, 98

---- microscopes, 95

---- objectives, 167

---- pathological microscope, 95

---- Star microscope, 101

Beggiatoa, 400

Benjamin Martin’s microscope, 5

Beroidæ, 519

Biaxial crystals, 228

Bilharzia hæmatobra, 573

Binocular microscope, advantage of, 69

---- ---- Carpenter on, 69

---- ---- Nachet’s, 62

---- ---- Pillischer’s, 128

---- ---- Riddell’s, 62

---- ---- Stephenson’s erecting, 71

---- ---- Wenham’s, 65

---- vision, 60

Bismarck-brown for staining protoplasm, 306

Bivalves, 538

Bleaching process, 315

Blood as a test, 263

---- circulation of, in frog’s foot, 665

---- ---- ---- tadpole, 665

---- corpuscles, 638

---- ---- double staining, 295

---- ---- size of, 640

---- crystals, 641

---- spectrum, 252

Bombay plague, 371

Bone, 658

---- of fish, 661

---- of reptilia, 660

---- structure of, 659

Borax, 231

Boring sponges, 513

Botterill’s live-trough, 276

Brachiopoda, 538

Branchipodidæ, 580

Brewster’s microscope, 11

Brittleworts, 427

Browning-Huggins micro-spectroscope, 245

Browning’s pocket lens, 76

Bryophyta, 444

Bryozoa, 531

Buchner’s experiments on yeast, 389

Bull’s-eye condensing-lens, 199

Butter, bacteria in, 393

Butterfly’s tongue, 605

---- wings, 610

Calc-spar, 231

Cambridge rocking microtome, 290

Camera lucida, the, 207

---- ---- the Abbé, 208

---- ---- the Wollaston, 207

---- Swift’s horizontal, 213

Canada balsam, 293

Carbonate of lead, 232

Carmine as a nuclear stain, 312

Cartilage, 655

Catheart’s freezing microtome, 291

Cedar oil, use of, 171

Cell, definition of, 358

Cell-making turn-table, Walmsley’s 340

Cells, epithelial, 636

---- for living objects, 276

---- for mounting, 340

---- live, 277

Cellulose, 357

---- staining, 314

Cements, 347

---- list of, 676

Centipedes, 578

Cercariæ, 571

Cereal parasites, 381

Chætophoraceæ, 409

Chara, fructification of, 417

---- mounting, 347

---- vulgaris, 415

Characeæ, 415

Cheese, bacteria in, 393

---- mite, 625

Chilinidæ, 551

Chitonidæ, 545

Chloride of gold as stain, 297

---- of palladium as stain, 298

Chromatic aberration, 25

---- ---- of the eye, 33

Chromic acid as hardening reagent, 288

Ciliata, 498

Circulation of the blood, 665

Cistula catenata, 558

Cladocera, 580

Clavatella prolifera, 521

Clearing agents, list of, 676

Clepsinidæ, 576

Clionæ, 513

Closterium, 424

---- lunula, 425

Cnidaria, 519

Cockchafer’s eye, 590

Coddington lens, the, 76

Codosiga, 497

Cœlenterata, 515

Cohn on multiplication of bacteria, 367

Cole’s direction for section cutting, 285

---- section-cutting microtome, 289

Collecting stick, Baker’s, 350

Collection of objects, 349

Compound microscope, 78

Compressor, Beck’s, 275

Compressorium, 274

---- Ross’s, 275

---- Rousselet’s, 275

Concave lenses, 23

---- surfaces, 17

Condenser, Abbé’s, 176

---- Baker’s Nelson, 184

---- ---- student’s, 184

---- Beck’s achromatic, 180

---- Gillett’s achromatic, 173

---- method of using, 190

---- Powell’s achromatic, 178

---- Ross’s achromatic, 176

---- Smith & Beck’s achromatic, 173

---- ---- substage, 193

Condenser, Swift’s, 183

---- Watson’s achromatic, 177

---- ---- parachromatic, 182

---- Webster-Collins, 186

---- Wenham’s immersion, 189

---- ---- parabolic, 186

Confervaceæ, 408

Conjugate foci, 17

---- real and virtual, 21

Continental microscopes, 130

Contrast stains, 313

Convex lens, 18

Copepoda, 580

Corals, 515, 525

---- true, 528

---- typical forms of, 533

Correction collar, Lister’s, 155

Coryne stauridia, 534

Cotton fibres, 474

Cover glass gauge, Zeiss’s, 165

Crinoids, 542

Critical angle, 14

Crookshank’s incubator, 324

---- method of staining bacteria, 335

Crustaceæ, 578

Crystals, formation and polarisation of, 239

Ctenophora, 518

Cuckoo-spit, 618

Culex pipiens, 596

Cultivation of bacteria, 327

---- of micro-organisms, 327

Cutleria dichotoma, 413

Cutting sections of hard woods, 316

Cuttle-fish, 556

Cyclops, 580

Cyclosis, phenomenon of, 359

Cyclostomata, 537

Cyclotus translucidus, 558

Cydippidæ, 518

Cymba olla, 557

Cymothordæ, 580

Dairy, bacteriology of, 393

Daphnia, enemies of, 581

---- ephippial eggs of, 580

Daphnia pulex, 580

De Bary’s investigations in parasitism, 395

Decalcifying and bleaching agents, list of, 677

Decalcifying solution as hardening reagent, 288

Demodex folliculorum, 627

Dental structure, 652

Dermestes lardarius, 627

Dermis, the human, 647

Desmidiaceæ, 420

---- reproduction of, 423

Diamond microscope, Pritchard’s, 9

Diaphragm, the, 194

---- the iris, 176

Diatomaceæ, 420, 427

---- fossilised, 437

---- Max Schultze’s researches, 430

---- where found, 428

Diatoms, mounting medium, 343

---- movements of, 431

Didymoprium grevelli, 420

Difflugia, 482

Digestive system of insects, 587

Dipping-tubes, 279

Disc-holder, Beck’s, 198

Dissecting-knives, 284

Dog-tick, 624

Double convex lens, 19

Draparnaldia glomerata, 409

Draw-tube, Swift’s, 116

---- Watson’s, 104

Drone fly, 594

Dytiscus marginalis, 607

Echinococcus, 565

Echinodermata, 539

Eggs of insects, 612

Elementary optics, 12

Embedding fluids, list of, 678

---- in paraffin wax, 285

Entomological specimens, mounting, 341

Entozoa, 562

Eosin stain, 315

Eozoon, 492

Epeira diadema, 619

Epidermis of plants, 455

Epithelial cells, 636

Epithelium, mounting, 295

Equisetaceæ, 449

Ergot of rye, 382

Eristalis tenax, 594

Erysiphe Tuckeri, 380

Eudorina, 406

Euglypta, 482

Eurotium repens, 383

Exposure table for photo-micrography, 213

Eye, chromatic aberration of the, 33

---- of cockchafer, 590

---- of fly, 588

---- of whirligig beetle, 608

---- the human, 30

Eye-piece, Abbé’s stereoscopic, 64

---- compensating, 147

---- ---- Zeiss’s, 147

---- Huyghenian, 139

---- Jackson’s micrometer, 143

---- Ramsden, 142

---- ---- micrometer, 145

---- Ross’s, 68

---- Wenham’s double, 63

---- Zeiss’s, 147

Eye-pieces, 139

---- achromatic, 149

---- magnifying powers of, 169

---- projections, 150

---- to clean, 259

Eyes of insects, 584

Favellidium, 415

Feet of insects, observation of, 604

Felices, 446

Fermentation experiments, 361

Fermentations, bacterial, 391

Ferns, 446

---- development of, 446

Fibro-cartilage, 657

Fibrous tissue, 642

---- ---- mounting, 296

Filaria sanguinis hominis, 568

Finder, the, 204

---- the Amyot, 205

---- the Maltwood, 204

---- the Okeden, 205

---- Pantacsek’s, 205

Fission formation, 365

Fixing solutions, list of, 678

Flabellum, 528

Flagella, staining of, 336

Flagellate infusoria, 495

Flatness of field, 262

Flax, fibres of, 474

Flea, 629

Florideæ, 413

Flowering plants, 451

Fluke, the, 569

Flustra, 532

Fly, eye of, 588

---- foot of, 602

Focal length of lenses, 22

Focus, method of finding, 271

Foot of fly, 602

Foraminifera, 483

Forceps, 283

---- for mounting, 294

---- stage, 198

Formation and polarisation of crystals, 239

Fossil plants, 475

Fossilised diatomaceæ, 438

Freezing agents, list of, 678

---- microtome, Cathcart’s, 291

---- ---- directions for using, 291

Frog-bit, 418

---- plate, 277

Froth-fly, 618

Fungi, industrial uses of, 391

Fungoid diseases, 374

Fungus on plants, 376

---- root, benefit to trees from, 396

---- sewage, 400

---- where found, 379

Gall-fly, 596

Gapeworm, 572

Gelatine, to prepare nutrient, 328

German yeast, 388

Gillett’s achromatic condenser, 173

Globigerina, 486

Glycerine agar-agar, 330

---- jelly, to make, 297

Gnat, 596

Gnathia, 579

Goniometer, Dr. Leeson’s, 150

Gorgoniidæ, 530

Gosse on noctiluca, 496

Gram’s method of staining bacteria, 335, 338

Grant’s researches on sponges, 507

Gregarinæ, 482, 563

Gromia, 484

Grove’s recommendations for mounting, 299

Gyrinus, eye of, 608

---- leg of, 608

Hæmatoxylin stain, 312

Hairs, structure of, 648

Haliotis splendens, 559

---- tuberculatus, 557

Hansen’s investigations of yeast, 387

Hard structures, mounting, 307

---- woods, cutting sections of, 316

Hardening agents, list of, 677

---- ---- absolute alcohol, 287

---- ---- chromic acid as, 288

---- ---- decalcifying solution as, 288

---- ---- methylated spirit as, 288

---- ---- Muller’s fluid as, 288

---- ---- potassium bichromate, 288

Hardening reagents, 287

---- tissue, 283

Hartea elegans, 535

Heliozoa, 489

Helix absoluta, 558

---- pomatia, 558

Hepaticæ, 442

Hexactinia, 526

Hirudina medicinalis, 576

Hirudinidæ, 575

His’s method of staining bacteria, 334

Holland’s simple microscope, 75

Holman’s life slide, 277

---- moist chamber, 277

---- syphon slide, 278

Holothurioidea, 543

Honey bee, 598

Horse-tails, 449

House fly, eye of, 588

---- proboscis of, 591

---- tongue of, 592

Human eye, the, 30

---- hair as a test, 269

Huyghenian eye-piece, 139

Hydra, 516

---- fasca, 516

---- stinging, 519

---- viridis, 516

Hydractinia echinata, 523

Hydroid polyps, colony of, 537

Hydrozoa, 515

Ianthinidæ, 550

Iceland spar, 221

Illumination arrangements of the microscope, 673

---- Mercer on, 673

Incubation, apparatus for, 322

---- test for, 263

Incubator, Crookshank’s, 324

Incubators, 324

Indigo plant, 392

Infusoria, 493

Infusorial life, 349

Injecting, directions for, 304

---- insects, 306

---- lower animals, 305

---- mollusca, 305

---- small animal bodies, 302

---- ---- ---- ---- syringe for, 302

---- with different colours, 304

Injections, to prepare, 303

---- ---- subjects for, 303

Injurious insects, 632

Insects, 578, 583

---- antennæ of, 584

---- digestive systems, 586

---- distinctive character of, 583

---- eggs of, 612

---- eyes of, 584

---- injecting, 306

---- injurious, 632

---- mouths of, 584

---- muscles of, 585

---- reproduction of, 587

---- respiratory system of, 607

---- thorax of, 585

---- wings of, 609

Interpretation, errors of, 263

Iris diaphragm, 176

Isthmia enervis, 436

Ixodidæ, 622

Ixodes ricinus, 624

Jackson’s micrometer eye-piece, 143

Jelly-fish, 519, 523

Jungermannia, 442

Koch’s method of staining flagella, 336

Lamp, Baker’s microscope, 191

---- Beck’s complete microscope, 202

---- shells, 539

---- the microscope, 201

---- Watson’s microscope, 203

Lard, embedding in, 285

Larvæ of sea-anemones, 529

Lathe for cutting sections of teeth, 308

Laticiferous tissues, 466

Leaf tissue, 466

Leeson’s goniometer, 150

Leeuwenhoek’s microscope, 4

Leitz’s dissecting microscope, 132

---- microscopes, 132

Lens, bull’s-eye condensing, 199

---- Steinheil’s aplanatic, 77

---- the Coddington, 76

Lenses, concave, 23

---- convex, 18

---- double convex, 19

---- focal length of, 22

---- forms of, 18

---- meniscus form of, 24

---- optical centre of, 20

---- plano-convex, 19

Lepas, 539

Lepisma saccharina, 612

---- scales of, as test, 264

Leptothrix buccalis, 400

Lichenaceæ, 439

Lichens, 439

---- erratic, 441

Lieberkühn’s microscope, 4

Lieberkühn, the, 198

Light, polarisation of, 219

Limax maximus, 558

---- rufus, 558

Limnæan, teeth of, 554

Limnæidæ, 551

Limnæus stagnalis, 551

Lingula pyramidata, 538

Lingulidæ, 538

List of salts, 240

Lister’s correction collar, 155

---- flasks, 322

---- microscope, 81

---- object glass, 154

Live-cages, 274

Live-cells, 277

Live-trough, Botterill’s, 276

Liverworts, 442

Lobosa, 482

Löffler’s method of staining flagella, 336

Logwood, staining by, 293

Lophopus crystallinus, 535

Lyda campestris, 598

Lymph corpuscles, 638

Maddox growing stage, the, 280

Magnifying powers of eye-pieces and objectives, 169

Maltwood finder, the, 204

Maple aphis, 617

Mapping spectra, 253

Marchantia polymorphia, 442

Martin’s microscope, 5

Marzoni’s objective, 152

Mayall’s illuminator, 184

---- mechanical stage, 124

Medusæ, 515, 521

---- a colony of budding, 537

Melicerta ringens, 505

Melolontha vulgans, eye of, 590

Meniscus form of lens, 24

Mercer on illumination, 673

Mesoglæa, 525

Mesoglia vermicularis, 410

Methylated spirit as hardening reagent, 288

Metric system of weights and measures, 687

Micrometer, Ramsden’s, 145, 206

---- the stage, 206

Micrometers, 205

Micro-organisms, 373

---- cultivation of, 327

Micro-photography, 210, 674

---- Baker’s apparatus for, 217

---- exposure table, 213

---- Pringle’s apparatus, 217

---- rules for, 214

---- Stringer-Watson’s apparatus for, 674

---- Swift’s apparatus for, 213

Microscope, accessories of the, 197

---- Baker’s advanced student’s, 123

---- ---- histological, 125

---- ---- Nelson model, 120

---- Beck’s binocular dissecting, 101

---- ---- ---- National, 99

---- ---- large Continental model, 98

---- ---- pathological, 95

---- ---- Star, 101

---- binocular, Pillischer’s, 128

---- ---- Wenham’s, 65

---- Carpenter on binocular, 69

---- compound, 78

---- early history of, 1

---- Holland’s simple, 75

---- Hooke’s water, 2

---- illumination arrangements of the, 673

---- invention of, 2

---- lamp, the, 201

---- ---- Baker’s, 191

---- ---- Beck’s, 202

---- ---- Watson’s, 203

---- Leitz’s dissecting, 132

---- Leeuwenhoek’s, 4

---- Lieberkühn’s, 4

---- Lister’s, 81

---- manipulation and mode of using the, 258

---- Martin’s, 5

---- Nachet’s, 133

---- ---- binocular, 62

---- Pillischer’s binocular, 128

---- ---- International, 126

---- Pillischer’s “Kosmos,” 128

---- Powell & Lealand’s, 85

---- ---- student’s, 88

---- Pritchard’s diamond, 9

---- Riddell’s binocular, 62

---- Ross’s “Eclipse,” 89

---- ---- New Industrial, 90

---- Ross-Jackson, 82

---- Ross-Jackson-Zentmayer, 83

---- Ross-Zentmayer, 91

---- Rousselet’s tank, 126

---- simple, 30, 72, 77

---- simple pocket, 73

---- Sir David Brewster’s, 11

---- Stephenson’s erecting binocular, 71

---- Swift’s advanced student’s, 118

---- ---- bacteriological, 116

---- ---- four-legged, 114

---- ---- histological student’s, 116

---- the bacteriological, 135

---- Watson’s bacteriological, 108

---- ---- Edinburgh student’s, 102

---- ---- histological, 107

---- ---- petrological, 111

---- ---- portable, 110

---- ---- Van Heurck’s, 108

---- Wenham’s binocular, 65

---- ---- radial, 90

---- Wollaston’s simple, 74

---- Zeiss’s, 130

Microscopes, Baker’s, 120

---- Beck’s, 95

---- Continental, 130

---- Leitz’s, 132

---- Pillischer’s, 126

---- Ross’s, 88

---- Swift’s, 113

---- Watson’s, 102

Microscopic forms of life, 353

---- vision, principles of, 45

---- ---- theory of, 37

Micro-spectroscope, the, 243

Micro-spectroscopic eye-piece, the Sorby-Browning, 247

---- method of using, 250

---- the Browning-Huggins, 245

Microtome, Cambridge rocking, 290

---- Cathcart’s freezing, 291

---- Cole’s section-cutting, 289

---- method of using, 289

Milk, bacteria in, 393

Millipedes, 578

Mineral and geological kingdoms, 670

Mirror, manipulation of, 260

---- the, 195

Mite, cheese, 625

Mites and ticks, 622

Moist stage, 280

Molecular rotation, 238

Mollusca, 545

---- injecting, 305

---- shell of, 558

Monads in rat’s blood, 372

Monoxenia, 523

Moss-animals, 531

Mosses, 443

Moulds, 380, 381

Mounting apparatus, 352

---- cells for, 340

---- chara, 347

---- entomological specimens, 341

---- epithelium, 295

---- fibrous tissue, 296

---- forceps, 294

---- hard structures, 307

---- media, list of, 678

---- nerve tissue, 296

---- non-striated muscle, 296

---- objects, materials required, 339

---- rock sections, 309

---- spring clip for, 296, 342

---- teeth sections, 308

---- vegetable tissues, 310

Mouse, hair of, 650

Mouth, leptothrix, 400

Mouths of insects, 584

Müller’s fluid, a hardening reagent, 288

Musca domestica, 588

Musci, 443

Muscidæ, 588

Muscles of insects, 585

Muscular fibre, 644

---- ---- mounting, 296

Mycetoma, 378

Mycetozoa, 482

Mycorhiza, 396

Nachet’s binocular microscope, 62

Nails, structure of, 648

Navicula, 427

Neckera antiphyretica, 445

Needles for teasing out sections, 286

Nematoid worms, 556

Nerve tissue, mounting, 296

Nicol prism, 220

Nitella, 418

Nitrate of silver as stain, 297, 298

Noctiluca, 496

Non-striated muscle, mounting, 296

Nose-pieces, 203

Nuclear stains, 311

---- ---- carmine, 312

---- ---- hæmatoxylin, 312

Nudibranchiata, 547

Nutrient agar-agar, to prepare, 330

---- gelatine, to prepare, 328

---- jelly, to inoculate with bacteria, 331

Object glass, Lister’s, 154

---- to clean, 260

Objective, achromatic, 152

---- changers, 203

---- Powell & Lealand’s oil immersion, 166

Objectives, Baker’s, 168

---- Beck’s, 167

---- English and German, 159

---- high power, 171

---- magnifying powers of, 169

---- Pillischer’s, 169

---- Ross’s, 166

---- Swift’s, 168

---- Watson’s, 167

Objects, collection of, 349

Oblique illumination, 186

Oidium albicans, 384

Okeden finder, the, 205

Onion, raphides of, 472

Opisthobranchiata, 548

Optical centre of lenses, 20

Optics, elementary, 12

Oscillariaceæ, 407

Osmic acid as stain, 298

Palates of gastrapods, 556

Palmellaceæ, 407

Palmoglæa macrococca, 401

Pandorina morum, 406

Parabolic reflector, 188

Paraffin wax, embedding in, 285

Parasites, cereal, 381

---- sponge, 512

---- vine, 380

Parasitic diseases of plants, 372

---- fungi of men and animals, 383

Parasitism, De Bary’s investigations in, 395

Patella radiata, 556

Pearls, structure of, 559

Pectinibranchs, 550

Pediastreæ, 422

Pedicellanæ, 543

Peltogaster curvatus, 539

Penetration in objective, 261

Pennatulidæ, 530

Pentacrinoids, 540

Pepperworts, 451

Peronospora viticola, 381

Petiole, 466

Phanerogamiæ, 451

Phanerogams, structure of, 453

Phloem of plants, 454

Pholadidæ, 545

Phomauvicola, 381

Photo-micrography, 210

---- apparatus for, 213

---- Baker’s apparatus for, 217

---- exposure table, 213

---- rules for, 214

---- Swift’s apparatus for, 213

Phylactolæmata, 533

Phylloxera vastatrix, 381

Physalia, 521

Physidæ, 551

Picro-carmine as stain, 299

Pigment cells, 446

Pillischer’s binocular microscope, 128

---- International microscope, 126

---- “Kosmos” microscope, 128

---- objectives, 169

Pinna ingens, 559

Pinnulariæ, 434

Pipette, 319

---- Pasteur’s bulb, 322

Plague, bacillus of, 370

---- the Bombay, 371

Planariæ, 575

Plano-convex lens, 19

Plants, epidermis of, 455

---- fibro-vascular system of, 460

---- flowering, 451

---- fossil, 475

---- ground tissue, system of, 458

---- hairs, 457, 473

---- parasitic diseases of, 374

---- raphides in, 472

---- reproductive organs of, 467

---- spores of parasitic fungus on, 376

---- structure of, 453

---- tissue systems of, 454

---- vascular system of, 464

Plasmodia, 482

Pleurobranchus aurantiacus, 548

---- plumula, 557

Pleurosigma angulatum, 429

---- as a test, 267

---- attenuatum, 429

Plumularia, 521

Pocket lens, Browning’s, 76

---- Coddington’s, 76

Podura-scale test, 268

---- villosa, 611

Polarisation apparatus, 223

---- of light, 219

---- prism, 220

---- ---- method of employing, 224

---- rotation of plane of, 231

Polarised crystal of quinidine, 235

Polarising apparatus, Watson’s, 224

Pollen grains, 467

---- ---- method of mounting, 467

Polycystina, 489

Polymorphina, 486

Polypomedusæ, 519

Polytrichum undulatum, 445

Polyzoa collecting, 350

Pond-snails, 551

Porifera, 506

Portable microscope, Watson’s, 110

Potassium bichromate as hardening reagent, 288

---- nitrate, crystal of, 232

Powell & Lealand’s microscope, 85

---- oil immersion objective, 166

---- student’s microscope, 88

---- formula for objective, 166

Preparing tissue, 283

Primordial cell, 357

Principal focus, 18

Pringle’s micro-photography apparatus, 217

Prism, 15

---- Nicol’s, 220

Pritchard’s diamond microscope, 9

Proboscis of house fly, 591

Proteolepas, 539

Protococcus invalis, 380

---- pluvialis, 401

Protoplasm, 356

---- staining living, 306

Protozoa, 478

Puccinia graminis, 375

Pyrocystis, 496

Quartz, 231

Quekett on Martin’s microscope, 6

Quinidine, crystals of, 235

Radiolaria, 490

Ramsden eye-piece, 142

---- micrometer eye-piece, 145

Raphides in plants, 472

Rayleigh’s theory of formation of optical images, 44

Reflection, 16

Reflector, Sorby’s, 199

Refraction, 13

---- through prism, 15

Reproductive organs of plants, 467

Resolving power, 262

Retiform tissue, 644

Rezner’s mechanical finger, 343

Rhizocarpeæ, 451

Rhizopoda, 482

Riddell’s binocular microscope, 62

Rochelle salt, 232

Rock limpet, 556

---- sections, mounting, 309

Ross’s achromatic condenser, 176

---- compressorium, 275

---- Eclipse microscope, 89

---- eye-pieces, 68

---- microscopes, 88

---- object glass, 154

---- objectives, 166

Ross-Hepworth arc lamp, 218

Ross-Jackson microscope, 82

Ross-Jackson-Zentmayer microscope, 83

Ross-Zentmayer microscope, 91

Rotatoria, mounting, 345

Rotifera, 502

Rousselet’s compressorium, 275

---- method of mounting rotatoria, 345

---- tank microscope, 126

Rye, ergot of, 382

Saccharomyces cerevisiæ, 384

---- ellipsoideus, 385

---- mycoderma, 384

Saccharomycetes, industrial uses of, 391

Salts, list of, 240

Saprolegnia ferox, 411

Sarcode, 357

Saw-fly, 598

Scalariidæ, 550

Scales of butterfly’s wings, 610

Scapander ligniarius, 557

Schäfer’s warm-stage, 282

Scyphomedusæ, 523

Sea-anemone, larvæ of, 529

Sea-anemones, 526

Sea-cucumber, 540, 543

Sea-hares, 549

Sea-mats, 532

Sea-urchin, 540

Sea-weeds, 409

Section cutting, 283

---- ---- Cole’s directions for, 285

Section-cutting microtome, Cole’s, 289

---- lifters, 319

---- scissors, 283

Sections of hard wood, cutting, 316

Selenite, 225

Sepia officinalis, 556

Sertularia, 521

Shadbolt’s turn-table, 295

Sheep-tick, 624

Shell, structure of, 558

---- formation in limnæa, 552

Sieve-tubes, 465

Silk filaments, 474

Silk-worm, 605

Silk-worms, disease of, 363

Silver-side reflector, 198

Simple microscopes, 30, 72, 77

Siphonophora, 521

Sirax gigas, 597

Skin, 646

Smith & Beck’s achromatic condenser, 173

Snow crystals, 237

Sorby-Browning micro-spectroscopic eye-piece, 247

Sorby’s reflector, 199

Spectroscope, cells for use with, 251

---- the, 244

Spectrum of chromule, 255

Sphæroplea annulina, 409

Sphærosira volvex, 406

Sphagnaceæ, 446

Spherical aberration, 23

Spiders, 619

Spirilla, 368

Spiro-bacteria, 368

Splenic fever bacillus, 369

Sponges, 506

---- boring, 513

---- Geodia Barretti, 510

---- Grant’s researches on, 507

---- hyalonema, 512

---- parasite on, 512

---- reproduction of, 510

Spongia coalita, 507

Spongiadæ, 506

Spore of parasitic fungus on plants, 576

Spores, 366

Spores, aerobic, 399

---- endogenous, 366

---- staining of, 336

Spring clip for mounting, 296, 342

Stage, Bartley’s warm, 281

---- forceps, 198

---- Maddox growing, 280

---- Mayall’s mechanical, 124

---- moist and warm, 280

---- Schäfer’s, 282

---- Stricker’s, 282

---- Watson’s semi-mechanical, 107

Stain, eosin, 315

Staining animal structures, 292

---- bacteria, 334, 338

---- by logwood, 293

---- cellulose, 314

---- double, 293

---- double and treble, 300

---- living protoplasm, 306

---- of flagella, 336

---- of spores, 336

---- tissue, 283

Stains and staining methods, list of, 679

Stains, chloride of gold, 297

---- chloride of palladium, 298

---- contrast, 313

---- double and treble, 300

---- nitrate of silver, 297, 298

---- osmic acid, 298

---- picro-carmine, 299

---- single, 298

Starch, 238

---- granules, 469

---- ---- of arrowroot, 470

---- ---- of potato, 470

---- ---- of wheat, 470

Star-fish, 540

Steinheil’s aplanatic lens, 77

Stentors, 501

Stephanoceros, 504

Stephanosphæra pluvialis, 403

Stephenson’s erecting binocular microscope, 71

Stereoscope, the, 60

Stereoscopic binocular vision, 60

Sterilised instruments, 321

Sterilisers, 324

---- Hearson’s, 325

---- steam, 325

---- ---- Dr. Koch’s, 325

Sting of bee, 596

---- of wasp, 596

Stock-bottle, 279

Stomata of iris, 456

---- water pores, 457

Stone-lilies, 542

Stonewort, 415

Stricker’s warm stage, 282

Stringer’s apparatus for micro-photography, 674

Stylonychia mytilus, 500

Stylopidæ, 628

Substage condenser, 193

Subterranean fungi, 397

Sun-animalcules, 489

Swift’s advanced student’s microscope, 118

---- bacteriological microscope, 116

---- draw-tube, 116

---- four-legged microscope, 114

---- histological student’s microscope, 116

---- horizontal camera, 213

---- illuminating apparatus, 183

---- microscopes, 113

-- objectives, 168

Tables, aperture, 58

Tænia, 564

Tanning skins, 393

Tardigrada, 631

Teasing out sections, needles for, 286

---- ---- ---- under condensed light, 287

Teeth, 652

---- lathe for cutting sections of, 308

---- method of cutting sections of, 308

---- mounting, 308

Tenent-hairs, 603

Terebella littoralis, 577

Terebratulata rubicuna, 559

Testacella maugei, 556

Test for illumination, 263

Test object, blood as a, 263

Test object, human hair as, 269

---- ---- lepisma as, 264

---- ---- pleurosigma, 267

---- ---- podura-scale, 268

Test-plate, Abbé’s, 164

Threadworm, 566

Thorax of insects, 585

Thuricola valvata, 500

Tick, dog, 624

---- sheep, 624

Ticks, 622

Tissue, adipose, 644

---- bacteria in sections of, 337

---- fibrous, 642

---- hardening, 283

---- preparing, 283

---- retiform, 644

---- staining, 283

---- systems of plants, 454

Tongue of butterfly, 605

---- of house fly, 592

---- of wasp, 595

Tooth substance, 654

Topaz, 231

Tourmaline, 225

Trematode worms, 569

Trichina spiralis, 567

Trichomes of plants, 457

Troughs, 274

Truffle, 397

Tuber cibarium, 397

Tubicola, 576

Tubipora, 530

Tubularia dumortierii, 537

Tunicata, 549

Turbo marmoratus, 557

Turn-table, Shadbolt’s, 295

Typhoid bacillus, 370

Ulvaceæ, the, 411

Ulva lactuca, 411

---- thermalis, 411

Urinary salts, 236

Vallisneria, 418

Varley’s live-box, 274

Varnishes, 339

Vascular system of plants, 464

Vaucheria, 410

Vegetable tissues, staining and mounting, 310

Veins, 662

Velutina lævigata, 557

Vertebrata, 633

Vine parasites, 380

Violet sea-snail, 550

Visual angle, 72

---- judgment, 37

Volvocineæ, 404

Vorticellidæ, 499

Walmsley’s turn-table, 340

Warm chamber, Pfeiffer’s, 323

---- stage, 280

---- ---- Bartley’s, 281

---- ---- Schäfer’s, 282

---- ---- Stricker’s, 282

Wasp, sting of, 596

---- tongue of, 595

Water thyme, 419

Watson’s achromatic condenser, 177

---- bacteriological Van Heurck’s microscope, 108

---- Edinburgh student’s microscope, 102

---- histological microscope, 107

---- mechanical draw-tube, 104

---- microscope lamp, 203

---- microscopes, 102

---- parachromatic condenser, 182

---- petrological microscope, 111

---- portable microscope, 110

---- semi-mechanical stage, 107

Webster-Collins condenser, 186

Weights and measures, metric system of, 687

Wenham’s binocular microscope, 65

---- double eye-piece, 189

---- immersion condenser, 189

---- parabolic condenser, 186

---- ---- reflector, 187

---- radial microscope, 90

Wheat rust, 374

---- starch, 470

Wheel animalcules, 502

Whirligig-beetle, eyes of, 608

---- ---- leg of, 608

Wings of butterfly, 610

---- of insects, 609

---- of moth, 610

Winogradsky’s investigations of bacteria, 398

Wollaston’s simple microscope, 74

Wood, formation of, 462

Wool, 474

Worms, 562

Wort-gelatine, 330

Xylem of plants, 462

Yeast cells, 384

---- German, 388

---- Hansen’s investigations of, 387

Zeiss’s compensating eye-piece, 147

---- cover-glass gauge, 165

---- microscope, 130

Zentmayer’s Holman syphon slide, 278

Zoophytes, 515

BRADBURY, AGNEW, & CO. LD., PRINTERS, LONDON AND TONBRIDGE.

Transcriber’s Note:

Page xxiii, “l. Corystes cossivelaunus” changed to read “l. Corystes cassivelaunus”.

Page xxv ERRATA incorporated into project.

Page xix, “Acmeœa virginea, part of palate--118.” changed to read “Acmæa virginea, part of palate--118.”

Page 21, “in Fig. 13, if S, S′ are a pair of conjugate foci,” changed to read “in Fig. 12, if S, S′ are a pair of conjugate foci,”. S and S′ are in Fig. 12.

Page 89 “Bacteriological and Histol gical” changed to read “Bacteriological and Histological”.

Page 598, “Apis nillifica” changed to read “Apis mellifica”, also entry in index.

Page 663, “the papillæ of the tongue is distended and seen erect” changed to read “the papillæ of the tongue are distended and seen erect”.

Obvious printer errors corrected silently.

Inconsistent spelling and hyphenation are as in the original.

FOOTNOTES:

[1] My earliest acquaintance with the Microscope occurred in the thirties, when I fortunately became possessed of a Culpeper-Scarlet instrument, figured in the title-page.

[2] At the time this was written, scarcely a book of the kind had been published at a price within the reach of the student.

[3] For fuller information, see the Cantor Lectures on the Microscope, by the late John Mayall, F.R.M.S., “Society of Arts Journal,” 1885.

[4] “A Practical Treatise on the Use of the Microscope.” London, 1855.

[5] For further information, I must refer my readers to Parkinson’s “Treatise on Optics;” Herschel’s “Familiar Lectures on Light;” “Cyclopædia Britannica;” Everett’s translation of Deschanel’s “Physics;” and Nägeli and Schwendener’s “Theory and Practice of the Microscope,” translated by Frank Crisp, LL.D.

[6] The cornea of the eye is not so entirely the simple transparent structure as it at first sight may appear to be. It is composed of several layers, the most important of which is the nerve layer, consisting of innumerable ganglionic stellate plexus of cells held together by a network, as seen in Fig. 21, a small section stained by chloride of gold, and magnified 300 diameters. Beneath the nucleated nerve cells is a second layer of stellate cells, varying a little in their form. These nerve and stellate cells serve the purpose of maintaining the cornea in health, and must play a significant part in the dioptric system.

[7] The standard condition of perfect vision is termed _emmetropia_.

[8] _Landolt_; “The Accommodation and Refraction of the Eye,” 1886.

[9] µ = ·001 of a millimetre. This measurement is now universally employed in microscopy.

[10] Diffraction effects may be observed without a microscope, indeed, the more striking are seen in connection with telescopic vision. A beautiful series of phenomena in illustration of the diffraction of light may be produced as follows: Draw on a large sheet of paper a series of geometrical figures, arranged at equal distances in a circle. A collodion photographic picture of these being taken, a series of small transparent apertures in the elsewhere opaque film will result. This film is then mounted, so that it may be in turn brought before the centre of a small hand telescope, previously adjusted to view an image of the sun. In this way we have an apparatus of the most compact form, and by means of which a series of fifty or more phenomena may be brought into view in a few minutes. These pictures being very small (occupying on an average area one-tenth of an inch in diameter), inaccuracies of surface and substance of the glass may be neglected. A film of Canada balsam with which the glass is cemented over the picture produces no disturbance. There is a manifest advantage in the figures being small, as the size of the image is in inverse proportion to the size of the aperture.

[11] Carpenter, “The Microscope,” p. 65, 1891.

[12] “Phil. Mag.,” viii., p. 167 (1896).

[13] Professor Stokes wrote me in the following flattering terms:--“What you have submitted to me on the subject of apertures is so sound, clear, and succinct, that I have nothing to add to it. The method adapted as you have explained respecting the immersion system, I consider to be perfectly satisfactory.” Subsequently, and at my request, Sir George Stokes contributed a valuable paper on the subject to the “Transactions of the Royal Microscopical Society,” 1876, on “The Theoretical Limit of Aperture.”

[14] “On the Estimation of Aperture in the Microscope,” “Journal of the Royal Microscopical Society,” series ii. vol. i.; “Notes on Aperture, Microscopic Vision, and the Value of Wide-angled Immersion Objectives,” 1881.

[15] _Numerical aperture_ is generally used in the sense in which it was introduced in 1873 by Professor Abbe, on the basis of his theoretical investigations. Numerical aperture represents the ratio between the radius of the effective aperture (_p_) of the system on the side where the image is formed--more accurately the radius of the emerging pencils measured in the upper focal plane of the objective--and the equivalent focal length (_f_) of the latter, _i.e._,

Numerical aperture = _p_/_f_.

This ratio is equal to the product of the sine of half the angle of aperture _u_ of the incident pencils and the refractive index _n_ of the medium, situated in front of the objective. With dry lenses _n_ has therefore the value 1; with immersion lenses it is equal to the refractive index of the particular immersion fluid:

Numerical aperture = _n_ Sin _u_.

The numerical aperture of a lens determines all its essential qualities; the brightness of the image increases with a given magnification and, other things being equal, as the square of the aperture; the resolving and defining powers are directly related to it, the focal depth of differentiation of depths varies inversely as the aperture, and so forth. (Abbe, “The Estimation of Aperture,” “Journal of the Royal Microscopical Society,” 1881, p. 389.)

[16] “Journal of the Royal Microscopical Society.”

[17] “Journal Roy. Micros. Soc.,” p. 19, 1878, and p. 20, 1880.

[18] “The Magnifying Power of Short Spaces” has been ably elucidated by John Gorham, Esq., M.R.C.S. “Journal of Microscopical Society,” October, 1854.

[19] The late Mr. Coddington, of Cambridge, who had a high opinion of the value of this lens, had one of these grooved spheres executed by Mr. Carey, who gave it the name of the Coddington Lens, supposing that it was invented by the person who employed him, whereas Mr. Coddington never laid claim to it, and the circumstance of his having one made was not known until nine years after it was described by Sir David Brewster in the “Edinburgh Journal.”

[20] “Journal of the Royal Microscopical Society, 1890,” p. 420.

[21] “Journal of the Royal Microscopical Society, 1880,” p. 1050.

[22] Apo-chromatic, from the Greek, signifying freedom from colour.

[23] Prof. Abbe “On Stephenson’s System of Homogeneous Immersion for Microscope Objectives,” “Journal of the Royal Microscopical Society,” II. (1879), p. 256, and on “The Essence of Homogeneous Immersion,” Ibid., I. (1881), p. 131.

[24] Reichert, in his catalogue, does not clearly indicate what the initial powers of his eye-pieces are.

[25] Messrs. Ross have two series of eye-pieces, both Huyghenian. One series is for use with the English 10-inch tube-body, and is distinguished by Roman letters, and the other by numerals, and made as is usual on the Continent, and for use with the shorter tube-body 6-1/2-inch. The initial powers given in the table are for the 10-inch tube, and for the shorter must be read as follows:--

1 2 3 4 } with 6-1/2-inch tube.
4 6 8 12 }

[26] This centring-glass consists of a tubular cap with a minute aperture, containing two plano-convex lenses, so adjusted that the image of the aperture in the object-glass and the images of the aperture of the lenses and the diaphragms contained in the tube which holds the illuminating combination, may be all in focus at the same time, so that by the same adjustment they may be brought sufficiently near to recognise their centricity.

[27] Summary of the value of parabolic illumination and immersion illuminators, by the late Mr. J. Mayall, will be found on p. 27, “Journal of the Royal Microscopical Society” (1879).

[28] Messrs. Baker and Swift have constructed lamps with removal and fixed achromatic bull’s-eye lenses in gymbal, and changeable tinted glass screens. Either of these will add to the usefulness of the lamp in bacteriological research work. Baker’s is constructed on the Herschel doublet formula, and should therefore be free from aberration. It is mounted on a heavy brass tripod foot, has vertical and horizontal movements by rack and pinion, brass reservoir, with screw opening for filling, metal chimney to take 3 × 1-1/2-inch glass slip, removable frame for carrying tinted glass screens, &c.

[29] “Journal of the Royal Microscopical Society,” p. 365, 1896.

[30] Dr. G. A. Piersoll, “American Annual of Photography,” 1890.

[31] “Journal of the Royal Microscopical Society,” 1892, p. 684.

[32] “Journal of the Royal Microscopical Society,” p. 578, 1897.

[33] Herapath’s test-fluid is a mixture of three drachms of pure acetic acid, one drachm of alcohol, and three drops of sulphuric acid.

[34] “Journal of the Royal Microscopic Society,” 1867.

[35] Born in 1787, at Straubing, a small town in Bavaria.

[36] Dr. Thudicum’s “Tenth Report of the Medical Officer of the Privy Council, 1867.” Mr. Sorby “On Some Improvements in the Spectrum Method of Detecting Blood.” “Journal of the Royal Microscopical Society,” 1871.

[37] “On the Reduction and Oxidation of the Colouring-matter of the Blood” (“Proc. of the Royal Soc.” vol. xiii. p. 355). The oxidising solution is made as follows:--To a solution of proto-sulphate of iron, enough tartaric acid is added to prevent precipitation by alkalies. A small quantity of this solution, made slightly alkaline by ammonia or carbonate of soda, is to be added to the weak solution of blood in water.

[38] “Journal of the Royal Microscopical Society,” 1869.

[39] Professor Sylvanus Thompson, “On the Measurement of Lenses,” “Journal of the Royal Microscopical Society,” 1892, p. 109.

[40] “Journal of the Royal Microscopical Society,” 2nd Series, Vol. iv., p. 542.

[41] Mr. J. F. Smith, “On the Structure of the Valve of Pleurosigma Pellucida,” “Quekett Club Trans.”

[42] “Quarterly Journal of Microscopical Science,” New Series, Vol. viii., 1878.

[43] It is quite possible also for the student to make his own microscope stand. Mr. Field in the “English Mechanic,” pp. 171 et seq., 1897, furnishes numerous working drawings for the construction of a high-class stand, together with patterns for the metal work.

[44] “Modern Microscopy,” by Martin J. Cole.

[45] With regard to the use of absolute alcohol, this re-agent requires to be used with caution; all minute details are lost, and it causes irregular shrinking of the finer tissues, while fibrous tissue is brought into undue prominence at the expense of the cellular elements. Consequently in certain biological laboratories the method of hardening in alcohol has been abandoned in favour of other re-agents.

[46] “Journal of Anatomy and Physiology,” XX. 1881, p. 349.

[47] “Journal of the Quekett Club,” July, 1893, and March, 1895.

[48] Mr. John Hood, 50, Dallfield Walk, Dundee, offers a weekly supply of infusorial life for a small annual subscription, or a single tube by post at the trifling cost of one shilling.

[49] Professor Marshall Ward, F.R.S., “Address to the Botanical Section of the British Association, 1897.”

[50] “British Medical Journal,” March 26, 1859; “Medical Times and Gazette” and “Popular Science Review,” 1862.

[51] “Parasitic Diseases,” “Journ. of the Royal Micros. Soc. of Lond.,” 1859-60.

[52] There are several other kinds of bacteria infesting milk, some of which are motile, others non-motile, producing acidity and colouring matter, as _B. prodigiosus_, red-milk; _B. synxanthus_, yellow milk; _B. lactis aerogens_, which are pathogenic; _B. lactis albus_, which coagulate milk; and another form, which is productive of slimy or ropy-milk.

[53] “Parasitic Diseases of the Skin,” 1859-73, p. 30. Bailliere, Tindal, and Cox.

[54] “Organic Germ Theory of Disease,” “Medical Times and Gazette,” p. 685, 1870.

[55] F. Cohn on the “Natural History of _Protococcus pluvialis_.”

[56] Pritchard’s “Infusoria,” p. 24, Plate I., 4th edition.

[57] In order to detect the presence of starch-grains in plants, the tissue must be kept in alcohol exposed to light, until the whole of the chlorophyll is dissolved out; it must then be treated for several hours in a strong solution of potash. After neutralisation with acetic acid, the tissue may be treated with iodine, which colours it blue, or with coralline solution, which colours it pink.

[58] Verhandl. d. Natur. Hist. Jahr. xx. p. 1. “Micros. Jour. Science,” vol. iii., p. 120.

[59] For instance, where the yellow Palmella is found the Chlorococcus will assume a yellow tinge in its soridial stage. Viewed by transmitted light the sori are seen as opaque balls, with an irregular outline.

[60] “Contributions to the Knowledge of the Development of the Gonidia of Lichens.” By J. Braxton Hicks, M.D., “Quarterly Journal of Microscopical Science,” vol. viii., 860, p. 239.

[61] Berkeley’s “Introduction to Cryptogamic Botany,” 1857.

[62] For more detailed information on the structure and classification of unicellular plants, and cryptogams, the reader is referred to Ralfs’ “British Desmidaceæ”; Smith’s “British Diatomaceæ”; Goebel’s “Outlines of Classification and Special Morphology”; Berkeley’s “Cryptogamic Botany”; De Bary’s “Comparative Anatomy of the Phaneragams and Ferns”; Professor Marshall Ward’s “Sach’s Physiology of Plants,” and numerous memoirs on Fungi; and Bower and Sidney Vine’s “Course of Practical Instruction in Botany,” a most instructive book on the histology of plants.

[63] “A Manual of the Infusoria,” by W. Saville Kent, F.L.S., &c., 1880.

[64] “Journal of the Linn. Society,” vol. viii., p. 202; vol. ix., p. 147, 1865 and 1866.

[65] Among the more important works on Foraminifera for consultation will be found D’Orbigny’s “Foraminiferes Fossiles du Bassin Tertiaire de Vienne” (Autriche); Schultze, “Ueber den Organismus der Polythalamien,” 1854; Carpenter and Williamson’s “Researches on the Foraminifera,” “Phil. Trans. 1856;” Parker and Rupert-Jones in the “Annals of Natural History.” Specimens of Foraminifera may be obtained by shaking dried sponges; but if required alive they must be dredged for, or picked off the fronds of living seaweeds, over the surface of which they are, by the aid of a lens, seen to move.

[66] W. Saville Kent, F.L.S., Op. Cit., p. 335.

[67] Difficulties formerly associated with the microscopic examination of flagellate forms of infusorial life have been overcome by improvements in the objectives, by the knowledge gained of the monad groups, and by the exhaustive researches of Drs. Drysdale and Dallinger, whose joint investigations were published in the Journal of the Royal Microscopical Society, 1873-75. By employing the highest and most perfectly constructed powers of the microscope, and devoting an enormous amount of time and attention to unravelling mysteries so long associated with the production of the lowly organised flagellate organisms, monads, and patiently watching hour by hour, the life-history of numerous species of these minute infusorial animalcules were obtained. Not only was it discovered that these organisms increased indefinitely by fission, but that under certain conditions two or more individuals were united into encystments, and whose contents broke up into a greater or less number of spore-like bodies, were speedily developed into the parent type. In the examination of these minute bodies, it has been found that talc-films, that is, talc split into extremely fine laminæ, offer the best kind of cover, in fact, supersede ordinary glass covers, and possess an advantage, that of bending readily, thus permitting the objective to be brought close down upon the object.

[68] R. Kirkpatrick, Warne, Op. Cit., pp. 532-3.

[69] Saville Kent, _op. cit._, p. 191.

[70] Fritz Müller first demonstrated a nervous system in the Polyzoa:--“The nervous system of each branch consisting of--1st, a considerable sized ganglion situated at its origin; 2nd, of a nervous trunk running the entire length of the branch, at the upper part of which it subdivides into branches, going to the ganglia of the internodes arising at this part; and 3rd, of a rich nervous plexus resting on the trunk, and connecting the ganglia just mentioned, as well as the basal ganglia of the individual polypides.” For further account, see paper in the “Micros. Journ.,” vol. i., New Series, p. 330.

[71] I have ventured to devote some considerable space to the development of the pond-snail, and for an obvious reason, that of making it perfectly clear to my readers that my microscopical investigations of Limnœa, made in 1853, were published in the “Journal of the Microscopical Society,” June, 1854, and republished in extenso in the several editions of this book, dating from the last mentioned period. Nevertheless, the fringe of cilia was, it appears, rediscovered in 1874, just twenty years after my paper was published. It is almost unnecessary to add that Carpenter gravely errs in his statement “that the existence of the fringe of cilia in the embryo snail had been overlooked until 1874.”

[72] Mr. George Rainey many years ago made us acquainted with the fact that certain of the appearances presented by the shell or other hard structures of animals, and which had hitherto been referred to as cell-development, are really governed by the physical laws which govern the aggregation of certain crystalline salts when exposed to the action of vegetable and animal substances in a state of solution. Mr. Rainey furnished a process for obtaining artificially a crystalline substance which shall so closely resemble shell structure that it can barely be distinguished from it. The chemical substances to be used in the preparation of the artificial shell, or calculi, are a soluble compound of lime and carbonate of potash or soda, dissolved in separate portions of water, and mixed with some viscid vegetable or animal substance, as gum or albumen, and mixing the several solutions together. The mechanical conditions required are that such a quantity of each of the viscid materials in each solution shall be of about the same density as that of the nascent carbonate of lime, and at perfect rest. This state of rest will require from two to three weeks or longer. Mr. Rainey shows the analogy or identity of his artificially formed crystals with those found in natural products both in animals and vegetables, chiefly confining himself to the structure and formation of shells and bone, pigmental and other cells, and the structure and development of the crystalline lenses, which he contends are all formed upon precisely the same physical principles as the artificial crystals.

[73] E. Ray Lankester, “On the Gregarinæ found in the common Earthworm.”--“Micros. Trans.” vol. iii. p. 83.

[74] For the fullest information of marine, land, and fresh-water species, consult Dr. Bastian’s “Monograph on the Anguillulidæ”; “Lin. Soc. Trans.” vol. xxv. p. 75; the “Anguillula Aceti,” by the author, in the “Popular Science Review,” January, 1863.

[75] “Cercaria parasitic on Limnœa,” “Jour. Royal Micros. Soc.” 1870.

[76] See my paper “The Natural History of a Nematode Worm,” “Journ. of Microscopy and Natural History,” October, 1888.

[77] “The Parasites of Man and the Diseases which proceed from them,” by Professor Rudolf Leuckart, 1886.

[78] R. J. Pocock, “On Worms” (Warne, Op. cit.), p. 465.

[79] An interesting account of the formation of the tubes of Serpula is given by Mr. Watson, “Jour. Micros. Soc.,” vol. 1890, p. 685.

[80] Dr. Baird, “Natural History of British Entomostraca,” printed for the Ray Society, 1850.

[81] See Mr. B. T. Lowne’s exhaustive treatise on “The Anatomy and Physiology of the Blow-fly,” a volume of 750 pages and 52 plates, 1891.

[82] Tuffen West, “Trans. Linn. Soc.,” vol. xxiii., p. 393.

[83] The term micropyle (a little gate) has heretofore only been used in its relation with the vegetable kingdom: it is used to denote the opening or foramen towards which the radicle is always pointed.

[84] Dr. Halifax adopts the method of killing the insect with chloroform; he then immerses it in a bath of hot wax, in which it is allowed to remain until the wax becomes cold and hard; with a sharp knife sections are easily made in the required direction without in the least disturbing any of the more fragile parts, or internal organs of the specimen.

[85] “Phil. Trans.,” 1859, p. 341.

[86] See my paper on “The Eggs of Insects,” in “The Intellectual Observer,” Oct. 1867, in which other varieties of eggs are given.

[87] W. U. Whitney, “Transactions of the Microscopical Society” for 1861 and 1867.

[88] Mr. F. G. Cuttell, 52, New Compton Street, Soho, cuts and prepares excellent sections.

[89] Published with his paper in detail, “Aperture as a Factor in Microscopic Vision,” “Journal of Royal Micros. Soc.,” June, 1808, pp. 334 _et seq._

[90] “Squire’s Methods and Formulæ;” “Modern Microscopy,” Cross and M. F. Cole; “The Microscopists’ Vade Mecum,” A. B. Lee; “Bacteriology.” Professor Dr. E. Crookshank, Messrs. Baird and Tattock, Cross Street, Hatton Garden, supply all Scientific Apparatus for Bacteriological Work.

[91] The imperial gallon contains 277.27384 cubic inches, and the imperial pint 20 fluid ounces, whereas the wine gallon has 231 cubic inches and the pint 16 fluid ounces. In wine measure 1 litre = 33.815 fluid ounces.

Transcriber’s Note:

Page xxiii, “l. Corystes cossivelaunus” changed to read “l. Corystes cassivelaunus”.

Page xxv ERRATA incorporated into project.

Page xix, “Acmeœa virginea, part of palate—118.” changed to read “Acmæa virginea, part of palate—118.”

Page 21, “in Fig. 13, if S, S′ are a pair of conjugate foci,” changed to read “in Fig. 12, if S, S′ are a pair of conjugate foci,”. S and S′ are in Fig. 12.

Page 89 “Bacteriological and Histol gical” changed to read “Bacteriological and Histological”.

Page 598, “Apis nillifica” changed to read “Apis mellifica”, also entry in index.

Page 663, “the papillæ of the tongue is distended and seen erect” changed to read “the papillæ of the tongue are distended and seen erect”.

Obvious printer errors corrected silently.

Inconsistent spelling and hyphenation are as in the original.