CONTENTS.
| [PART I]. | |
|---|---|
| PAGE | |
| Early History of the Microscope | 1 |
| [CHAPTER I]. | |
| Light—Its Propagation—Refraction—Spherical and Chromatic Aberration—Human Eye—Formation of Images—Visual Angle—Abbé’s Theory of Microscopic Vision—Definition of Aperture—Numerical Aperture—Abbé’s Apertometer—Stereoscopic Binocular Vision | 12 |
| [CHAPTER II]. | |
| Simple and Compound Microscopes—Evolution of the Modern Achromatic Microscope—Improvements in the Modern Microscope: The Ross-Jackson, Powell and Lealand, Beck’s, Baker’s, Pillischer, Zeiss, Leitz, Watson’s, Van Heurck’s Edinburgh Students’, Swift’s, and Bacteriological | 72 |
| [CHAPTER III]. | |
| Applied Optics—Eye-pieces—Achromatic Objectives and Condensers—Magnifying Power of Eye-pieces and Objectives—Method of Employing the Condenser—Its Illumination Mirror—Accessories of the Microscope—Finders—Micrometers—Camera-Lucida—Microscope in Position for Drawing—Abbé’s Test-Plate—Micro-Photography—Polarisation of Light—The Micro-Spectroscope | 139 |
| [CHAPTER IV]. | |
| Practical Microscopy—Manipulation—Mode of Employing the Microscope—Working Accessories—Methods of Preparing, Hardening, Staining, and Section Cutting—Cutting Hard Structures—Injecting Apparatus, Material, etc., employed in Bacteriological Investigations—Warm Chambers and Incubators—Preparing, Mounting, Cementing, and Collecting Objects | 258 |
| [PART II]. | |
| [CHAPTER I]. | |
| Microscopic Forms of Life—Thallophytes, Pteridophyta, Phanerogamæ—Structure and Properties of the Cell—Pathogenic Fungi and Moulds—Parasitic Diseases of Plants, Man, and Animals—Industrial Uses of Fungi and Saccharomycetes—Desmidiaceæ and Diatomaceæ—Lichens, Mosses, Ferns, Flowering Plants | 353 |
| [CHAPTER II]. | |
| Sub-Kingdom Protozoa—Rhizopoda—Gromia and Foraminifera—Infusoria—Ciliata—Rotifera—Porifera—Sponges | 478 |
| [CHAPTER III]. | |
| Zoophytes—Cœlenterata—Medusæ—Corals—Hydrozoa—Mollusca—Annulosa—Worms—Entozoa—Annelida—Crustacea | 515 |
| [CHAPTER IV]. | |
| Arthropoda—Insecta—Arachnida—Acarina—Ixodidæ—Mites and Ticks | 583 |
| [CHAPTER V]. | |
| Vertebrata—Internal and External Structures | 633 |
| [CHAPTER VI]. | |
| The Mineral and Geological Kingdoms | 670 |
| [APPENDIX]. | |
| Dr. Mercer on Illumination, and Abbé’s Theory—Micro-Spectroscope—Formulæ, Methods, Cementing, Clearing, Hardening, and Mounting—Tables, Metric and Thermometric | 672 |
| [INDEX] | 691 |
DESCRIPTION OF PLATES,
COLOURED AND PLAIN.
[FRONTISPIECE].
RADIOLARIA.
In this Plate Fig. 1 shows the elegant lattice-sphere of Rhizosphæra; Fig. 2 represents Sphærozoum, whose skeleton consists of loose spicules, arranged tangentially; Actinomma, Fig. 3, possesses three concentric lattice-spheres, joined by radiating spines; Figs. 4, 5, and 6, represent Lithomespilus, Ommatocampe, and Carpocanium; Fig. 7 represents a deep-sea form (Challengeria), whose oval case is formed of a regular, very fine-meshed, network; Fig. 8 depicts the elegant lattice-sphere of Heliosphæra; Figs. 9 and 10, Clathrocyclas and Dictyophimus.
[PLATE I.—Page 400.]
PROTOPHYTA. THALLOPHYTES.
Fig. 1. Peziza bicolor—2. Truffle: a. ascus of spores; b. mycelium—3. Sphæria herbarum: a. piece of dead plant, with S. herbarum natural size; b. section of same, slightly magnified; d. Ascus with spores, and paraphyses more magnified—4. Peziza pygmæa—5. Apical form of same—6. P. corpulasis: Ascus with spores and paraphyses, merely given as a further illustration of structure in Peziza—7. Yeast healthy—8. Yeast exhausted—9. Phyllactinia guttata—10. Yeast with favus spores and mycelium of fungus—11. Favus ferment, with oïdium and bacteria—12. Puccinia spores, growing in a saccharine solution—13. Aerobic bacteria—14. Spores and mycelia from eczema produced by yeast—15. Volvox globator—16. Amœboid condition of portion of volvox—17. Puccinia buxi—18. Ditto, more enlarged—(17 to 20 illustrate Ascomycetes.)—19. Æcidium grossulariæ from transverse section of leaf of currant: a. spermogones on upper surface; b. perithecia with spores—20. Phragmidium bulbosum, development of—21. Palmella parietina, trans. section through a spermogone, showing green gonidia and spermatia escaping—22. Æcidium berberida, from leaf of berberry—23. Vaucheria sessilis—24. Stephanosphæra pluvialis: a. Full-grown example, germ cells spindle-shaped with flagella; b. Resting-cell; c. division into four; d. Free-swimming ciliated young specimen; e. Amœboid condition—25. a, b, c, d, e, f and g, Development of lichen gonidia—26. Palmella stellaris (lichen), vertical section through apothecium, showing asci, spores, and paraphyses, with gonidia and filamentous medulla: a. Spermatophore with spermatia—27. Moss gonidia assuming amœboid form.
Typical forms of Protophyta; 7 to 14, modes of development or rudimentary conditions; Confervoideæ, 23; Vaucheria, Stephanosphæra, 24; Volvox, 15, &c.
[PLATE II.—Page 412].
PROTOPHYTA. ALGÆ.
Fig. 27. Ceramium acanthonotum—28. Closterium, Triploceras gracilis—29. Cosmarium radiatum—30. Micrasterias denticulata—31. Docidium pristidæ—32. Callithamnion plumula—33. Diatoma, living: a. Licmophora splendida; b. Achnanthes longipes; c. Grammatophora marina. These figures are intended to show the general character of the endochrome and growth of frustule—34. Callithamnion refractum—35. Jungermannia albicans; b. representing elater and spores—36. Leaf with antheridia, or male elements, represented more magnified at a to the left of the figure—37. Ceramium echinotum—38. Pleurosigma angulatum, side view—39. Delesseria hypoglossum—40. Pleurosigma angulatum, front view, endochrome not represented—41. Ceramium flabelligerum.
[PLATE III.—Page 479].
PROTOZOA.
Figs. 43, 44, 45, 46, 47, 48, 49, 50, 51, 52. These figures are from drawings made by Major Owen, to illustrate forms of living Polycystina, sketched from life; these convey a faint idea of the richly coloured appearance of the natural structure; Figs. 48 to 52—53. Gregarina lumbricorum, round form—54. Gregarina lumbricorum, the usual elongated form—55. Gregarina serpulæ—56. Gregarina Sieboldii; illustration of septate form, with reflexed hook-like processes—57. Gregarina lumbricorum, encysted—58. Gregarina lumbricorum, more advanced and pseudo-navicellæ forming—59. Gregarina lumbricorum, free pseudo-navicella of—60, 61. Gregarina lumbricorum, amœboid forms of—62. Cruciate sponge-spicule—63. Astromma Humboldtii—64. Eözoon Canadense, represents appearance of a portion of the natural size—65. Eözoon Canadense, magnified, showing portions of cell-walls left uncoloured, the animal sarcode inhabiting it coloured dark green as in nature, and converted by fossilisation into a silicious mineral; the narrow bands passing between these are processes (stolons) of the same substance—66. Actinophrys sol, budding—67. Euglena viridis: a. contracted; b. elongated form—68. Acineta tuberosa—69. Œcistes longicornis (Davis)—70. Oxytricha gibba (side view)—71. Oxytricha pellionella—72. Thuricola valvata, expanded—73. Cyclidium (glaucoma)—74. Oxytricha scintillans—75 to 79, 80 to 85, illustrate types of Foraminifera discovered by Major Owen, living—75. Globigerina acerosa, n. sp., broken open to show interior—76. Globigerina, n. sp., broken open to show interior—77. Globigerina hirsuta—78. Globigerina universa—79 and 81. G. Bulloides—80. Conochilus vorticella—82. Globigerina inflata, sinistral shell—83. Pulvinulina Micheliniana—84. P. Canariensis—85. P. Menardii.
[PLATE IV.—Page 514].
METAZOA. BRYOZOA.
Fig. 86. Hartea elegans—87. Side view of Synapta spicula—88. Ophioglypha rosula (very immature specimen): a. Claw hooks; b. palmate spicula. The development of this species is described by G. Hodge, in “Transactions of Tyneside Naturalists’ Field-Club”—89. Spine of a star-fish, particularly interesting as showing the reticular calcareous network obtaining in this as in all other hard parts of the Echinodermata—90. Very minute Spatangus, obtained from stomach of a bream: many of the spines are gone, but the structure of the shell is intact and forms a beautiful object, interesting in connection with the source whence obtained—91. Ophioglypha neglecta: wriggling or brittle starfish. The plate does not admit of a figure on a scale sufficient to show the full beauty of this object—92. Tubularia Dumortierii—93. Pedicellaria mandibulata from Uraster glacialis—94. Pedicellaria forcepiforma, from the same—95. Cristatella mucedo; 96. Edge-view of statoblast; 97. early stage in development of same—98. Lophopus crystallinus—99. Plumatella repens with ova, on submerged stem—100. Tænia echinococcus—101. Hydatids from human liver—102. Bilharzia hæmatobia—103. Amphistoma conicum—104. Trichina spiralis from fleshy part of Hambrc’ pork—105. Trichina spiralis male, separated from muscle.—106, 107. Fasciola gigantea.
[PLATE V.—Page 556].
MOLLUSCA.
Fig. 108. Velutina lævigata, portion of lingual membrane—109. Velutina lævigata, part of mandible—110. Hybocystis blennius, portion of palate—111. Sepia officinalis, portion of palate—112. Aplysia hybrida, part of mandible—113. Loligo vulgaris, part of palate—114. Haliotis tuberculatus, part of palate—115. Cistula catenata, part of palate—116. Patella radiata, part of palate—117. Acmæa virginea, part of palate—118. Cymba olla, part of palate—119. Scapander ligniarius—120. Oneidoris bilamellata, part of palate—121. Testacella Maugei, part of palate—122. Pleurobranchus plumula, part of mandible—123. Turbo marmoratus, part of palate.
Lingual membranes of Mollusca; drawings made from specimens in the collection formed by F. E. Edwards, Esq., now in the British Museum. Typical examples of the numerous forms of Odontophors met with in Gasteropod and Cephalopod Mollusca.
[PLATE VI.—Page 582].
INSECTA.
Fig. 124. Egg of Caradrina morpheus, mottled rustic moth—125. Egg of tortoise-shell butterfly, Vanessa urticæ—126. Egg of common footman, Lithosia complanula—127. Egg of shark moth, Cucullia umbratica—128. Maple-aphis—129. Egg shell of acarus, empty—130. Egg of house-fly—131. Mouth of Tsetse-fly, Glossina morsitans—132. Vapourer moth, Orgyia antiqua: antenna of male—133. Vapourer moth: antenna of female; a. branch more magnified to show rudimentary condition of the parts—134. Tortoise-shell butterfly; head in profile, showing large compound eye, one of the palpi, and spiral tongue—135. Tortoise-beetle, Cassida viridis; under surface of left fore-foot, to show the bifurcate tenent appendages, one of which is given at a more magnified. This form of appendage is characteristic of the family. “West on Feet of Insects,” Linn. Trans. vol. xxiii. tab. 43-136. Egg of blue argus butterfly, Polyommatus argus—137. Egg of mottled umber, Erannis defoliaria—138. Egg of Ennomos erosaria, thorn-moth—139. Egg of Aspilates gilvaria, straw-belle—140. Blow-fly, Musca vomitoria: left fore-loot, under-surface, to show tenent hairs; a b more magnified; a from below, b from the side—141. House-fly larva—142. Amara communis: left fore-foot, under-surface, to show form of tenent appendages, of which one is given more magnified at a. These, in ground beetles, are met with only in the males, believed to be used for sexual purposes. These appendages are carefully protected when not in use, as explained by West—143. Ephydra riparia: left fore-foot, under-surface. This fly is met with sometimes in immense numbers on the water in salt-marshes; it has no power of climbing on glass, as seen by the structure of the tenent hairs; the central tactile organ also is peculiar, the whole acting as a float, one attached to each foot, enabling the fly to rest on the surface of the water; a. an enlarged external hair—144. Egg of bot-fly, the larva just escaping—145. Egg of parasite of pheasant—146. Egg of Scatophaga—147. Egg of parasite of magpie—148. Egg of Jodis vernaria, small emerald moth.
[PLATE VII.—Page 633].
VERTEBRATA.
Fig. 149. Toe of mouse, integuments, bone of foot, and vessels—150. Tongue of mouse, showing erectile papillæ and muscular layer—151. Brain of rat, showing vascular supply—152. Vertical section of tongue of cat, fungi-form papillæ and capillary loops passing into them, vessels—153. Kidney of cat, showing Malpighian turfts and arteries—154. Small intestine of rat, with villi and layer of mucous membrane exposed—155. Nose of mouse, showing vascular supply to roots of whiskers—156. Vascular supply to internal gill of tadpole, during one phase of development—157. Section through sclerotic coat and retina of cat’s eye, showing vascular supply of choroid vessels cut cross-ways—158. Interior of fully-developed tadpole, exhibiting heart, vascular arrangement and vascular system throughout body and tail.
This plate is designed to show the value, in certain cases, of injected preparations in the delineation of animal structures. By thus artificially restoring the blood and distending the tissues, a better idea is obtained of the relative condition of parts during life.
[PLATE VIII.—Page 220].
POLARISCOPE OBJECTS.
Fig. 158. New Red Sandstone—159. Quartz—163. Granite—161. Sulph. Copper—162. Saliginine—163. Sulph. Iron and Cobalt, crystallized in the way described by Thomas—164. Borax—165. Sulph. Nickel and Potash—166. Kreatine—167. Starch granules—168. Aspartic Acid—169. Fibro-cells, orchid.—170. Equisetum cuticle—171. Holothuria spicula, Australia—172. Holothuria spicula, Port Essington—173. Deutzia scabra; upper and under surface—174. Cat’s tongue, process—175. Prawn shell, exuvia with crystals of lime—176. Grayling scale—177. Scyllium caniculum scale—178. Rhinoceros horn, transverse section—179. Horse hoof—180. Dytiscus, elytra with crystals of lime.
[PLATE IX.—Page 362].
TYPICAL PLATE OF BACTERIA AND SCHIZOMYCETES.
Fig. 1. Cocci, singly, and varying in size—2. Cocci in chains or rosaries (streptococcus)—3. Cocci in a mass (staphylococcus)—4 and 5. Cocci in pairs (diplococcus)—6. Cocci in groups of four (merismopedia)—7. Cocci in packets (sarcina)—8. Bacterium termo—9. Bacterium termo × 4000 (Dallinger and Drysdale)—10. Bacterium septicæmiæ hæmorrhagicæ—11. Bacterium pneumoniæ crouposæ—12. Bacillus subtilis—13. Bacillus murisepticus—14. Bacillus diphtheriæ—15. Bacillus typhosus (Eberth)—16. Spirillum undula (Cohn)—17. Spirillum volutans (Cohn)—18. Spirillum choleræ Asiaticæ—19. Spirillum Obermeieri (Koch)—20. Spirochæta plicatilis (Flügge)—21. Vibrio rugula (Prazmowski)—22. Cladothrix Försteri (Cohn)—23. Cladothrix dichotoma (Cohn)—24. Monas Okenii (Cohn)—25. Monas Warmingii (Cohn)—26. Rhabdomonas rosea (Cohn)—27. Spore-formation of Bacillus alvei—28. Spore-formation (Bacillus anthracis)—29. Spore-formation in bacilli cultivated from rotten melon (Fränkel and Pfeiffer)—30. Spore-formation in bacilli cultivated from earth (Fränkel and Pfeiffer)—31. Involution-form of Crenothrix (Zopf)—32. Involution-forms of Vibrio serpens (Warming)—33. Involution-forms of Vibrio rugula (Warming)—34. Involution-forms of Clostridium polymyxa (Prazmowski)—35. Involution-forms of Spirillum choleræ Asiaticæ—36. Involution-forms of Bacterium aceti (Zopf and Hansen)—37. Spirulina-form of Beggiatoa alba (Zopf)—38. Various thread-forms of Bacterium merismopedioides (Zopf)—39. False-branching of Cladothrix (Zopf).
[PLATE X.—Page 420].
DESMIDIACEÆ.
Fig. 1. Euastrum oblongum—2. Micrasterias rotata—3. Desmidium quadrangulatum—4. Didymoprium Grevillii—5. Micrasterias, sporangium of—6. Didymoprium Borreri—7. Cosmarium Ralfsii—8, 9. Xanthidiæ—10. X. armatum—11. Cosmarium crenatum—12. C. Sphærozosma vertebratum—13, 17. Sporangia of Cosmarium—14. X. fasiculatum—18. Staurastrum hirsutum—19. Arthrodesmus convergens—15. Staurastrum tumidum—16. Staurastrum dilitatum—21. Penium—22. Euastrum Didelta—23. Docidium clavatum—24. Pediastrum biradiatum—25. Closterium, showing conjugation or self-division—26. Volvox, parent cell about to break up—27. Penium Jennerii—28. Aptogonum desmidium—29. Pediastrum pertusum—30. Ankistrodesmus falcatus—31. Parent cell of Closterium—32. Staurastrum gracilis.—33. Conjugation of Penium margaritaceum—34. Spirotænia—35. Closterium
[PLATE XI.—Page 428].
DIATOMACEÆ.
Fig. 1. Arachnoidiscus—2. Actinocyclus (Bermuda)—3. Cocconeis (Algoa Bay)—4. Coccinodiscus (Bermuda)—5. Isthmia enervis—6. Zygoceros rhombus—7. Campilodiscus clypeus—8. Biddulphia—9. Gallionella sulcata—10. Triceratium, found in Thames mud—11. Gomphonema geminatum, with their stalk-like attachments—12. Dictyocha fibula—13. Eunotia—14. Cocconema—15. Fragilaria pectinalis—16. Meridion circulare—17. Diatoma flocculosum.
[PLATE XII.—Page 438].
MICRO-PHOTOGRAPH OF TEST DIATOMS.
Taken with Zeiss’s 3 mm. N.A. 1·40 by Mr. A. A. Carvell for the Author.
Fig. 1. Portion of Surirella gemma, magnified × 1,000—2. Broken Frustule of Pleurosigma angulatum, × 750—3 and 5. Triceratium favus ×—1,000—4. Navicula rhomboides × 1,300—6. Pleurosigma formosum, showing black dots—7. P. formosum, showing white dots, × 750.
[PLATE XIII.—Page 454].
PHANEROGAMIÆ—ELEMENTARY TISSUE OF PLANTS.
Fig. 1. Elementary ovid cells—2. Branching tissue—2A and 3. Spiral vessels from Opuntia vulgaris—4. Stellate tissue, section of rush—5. Mushroom spawn—6. Starch from Tous-les-mois—7. Starch from sago—8. Starch from rice—9. Wheat-starch—10. Rhubarb starch in isolated cells—11. Maize-starch—12. Oat-starch—13. Barley-starch—14. Section of Potato cells, filled with healthy starch—15. Potato starch more highly magnified—16. Section of Potato with nearly all starch absent—17. Potato with starch destroyed by fungoid disease—18. Ciliated spermagones—19. Hairs of stinging-nettle—20. Section of cellular parenchyma of ripe strawberry.
[PLATE XIV.—Page 472].
STELLATE AND CRYSTALLINE TISSUE.
Fig. 1. Epidermis of husk of wheat, spiral vessels and silicious crystals—2. Section of cane, silicious cell walls, internal portion filled with granular bodies—3. Cuticular layer of the onion, showing crystals of calcium carbonate and oxalate—4. Cells of garden rhubarb, with crystalline bodies and raphides—4a. Another layer filled with starch grains—5. Section of pear, testa, sclerogenous and granular tissue—6. Stellate hairs, sinuous cells and silicious parenchyma of leaf of Deutzia scabra, under surface—7. Silicious cuticle layer of grass, Pharus cristatus.
[PLATE XV.—Page 482].
RHIZOPODA.—GROMIA.—FORAMINIFERA.
Fig. 1. Astrorhiza limicola—2. Lieberkühnia paludosa—3. Micro-gromia socialis undergoing fission—4. A colony of Hertwig’s Micro-gromia socialis—5. G. Lieberkühnia—6. Egg-shaped Gromia, G. oviformis, with pseudopodia extended, magnified 500 diameters. “Hertwig Ueber Micro-gromia, archiv. für Mickr. Anat. bdx.”
[PLATE XVI.—Page 510].
SPONGE SPICULES.
Fig. 1. A portion of sponge, Halichondria simulans, showing silicious spicula imbedded in the sarcode matrix—2. Spicula divested of its matrix by acid—3. Gemmule Spongilla fluviatallis enclosed in spicula—4. Birotulate spicula from same—5. Gemmule after being steeped in acid showing reticulated coating of birotulate spicula—6. Gemmules of Geodia—7. Gemmule in more advanced stage of growth—8. Skeleton of the acerate form covered by rows of spines—9. Showing rings of growth and horny covering, and bundles of spicula of the genus Verongia—10. Sphero-stellate spicula of Tethya—11. Tricuspidanchorate and sphero-stellate spicula—12. Acuate-bi-clavate and other forms of spicula from Geodia—13. Clavate spicula covered with short spines.
[PLATE XVII.—Page 518].
ZOOPHYTES, ASTEROIDS, NUDIBRANCHS, AND ECHINOIDS.
Fig. 1. a. Astrophyton scutatum—b. Doris pinnatifida, back and side view—c. Æquorea Forbesina—d. Medusæ bud—e. Thaumantias corynetes—f. Echinus in an early free stage—g. Echinus sphæra—h. Cydippe pyleus—i. Ascidiæ—k. Botryllus violaceus, on a Fucus—l. Corystes cassivelaunus—m. Eurynome aspera—n. Ophiocoma rosula—o. Pagurus Prideauxii—p. Ebalia Permantii.
[PLATE XVIII.—Page 558].
SHELLS OF MOLLUSCA.
Fig. 1. Transverse section of spine of Echinus—2. Another section of Echinus, showing reticulated structure, the calcareous portion dissolved out by acid—3. Horizontal section of shell of Haliotis splendens, showing stellate pigment—4. Shell of crab with granules in articular layer—5. Another section of same shell, showing hexagonal structure—6. Horizontal section of coach-spring shell, Terebratulata rubicunda, showing radiating perforations—7. Transverse section of shell of the Pinna ingens—8. Crystals of carbonate of lime, from oyster shell.
[PLATE XIX.—Page 636].
VERTEBRATA.
Fig. 1. a. Spheroidal epithelium cells, filled with central nuclei and granular matter; b. mucous membrane of stomach, showing cells, with open mouths of tubes at the bottom of each, magnified 50 diameters—2. a. Diagram of a portion of the involuted mucous membrane, showing continuation of its elements in the follicles and villi, with a nerve entering the submucous tissue. The upper surface of one villus is covered with cylindrical epithelium; the other denuded, and with dark line of basement membrane running around it; b. epithelium cells, separated and magnified 200 diameters, a central nucleus, with a nucleolus, seen in centre; c. pavement epithelium cells, from the mucous membrane of bronchial or air tubes with nuclei, and nucleoli in some; d. vibratile or ciliated epithelium, nuclei visible, and cilia at the upper free surface, magnified 200 diameters—3. a. is one of the tubular follicles from a pig’s stomach, cut obliquely to display upper part of cavity, and the cylindrical epithelium forming its walls, a few cells detached; b. shows a section of a lymphatic, with capillary blood-vessels, distributed beneath the mucous surfaces—4. Cells of adipose tissue, or fat, magnified 100 diameters—5. a single fat-cell separated, and magnified 250 diameters—6. A capillary of blood-vessels distributed through tissue—7. Section of the Tendo-Achillis as it joins the cartilage, showing stellate cells of tendon, seen to be gradually coalescing to form round or oval cells of cartilage—8. A vertical section of cartilage, with clusters of cells arranged in columns previous to their conversion into bone—9. A small transverse section of the same, showing the gradual change of the cartilage cells at a. into the true bone cells, lacunæ, at b. with characteristic canaliculi—10. A stellate nerve corpuscle, with tubular processes issuing forth, at a. filled with corpuscles containing black pigment, above which is a corpuscle the nucleus of which is seen to have nucleoli; at b. a corpuscle enclosed within sheath, and filled with granular matter taken from the root of a spinal nerve—11. The continuity of muscle, the upper portion, with connective tissue of the lower portion, from the tongue of a lamb—12. Branched muscle, ending in stellate connective cells, from the upper lip of the rat—13. Choroidal black pigment-cells from the human eye.
[PLATE XX.—Page 658].
BONE STRUCTURE.
Figs. 1. and 2. Transverse section of the human clavicle (collar bone), showing Haversian canals, concentric laminæ, and concentric arrangement of bone cells—3. Transverse section of the femur of an ostrich—4. Transverse section of humerus (fore-arm) bone of a turtle, Chelonia mydas—5. Horizontal section of the lower jaw-bone of a conger eel, in which no Haversian canals are present—6. A portion of the cranium of a siren, Siren lacertina—7. Portion of bone taken from the shaft of humerus of a Pterodactyle, showing elongated bone-cells characteristic of the order Reptilia—8. Horizontal section of a scale, or flattened spine, from the skin of a Trygon (sting-ray), showing large Haversian canals, numerous wavy parallel tubes, also bone-cells with canaliculi communicating as in dentine.