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.