LIST OF ILLUSTRATIONS. FIG. 1. Protococcus pluvialis, 2. Zygnema, or Yoke-thread, 3. Oscillatoria, 4. Pandorina morum, 5. Volvox globator, 6. (a) Euglena viridis, (b) Euglena viridis, with flagellum, (c) Euglena viridis, with flagellum, bulbed, 7. Cosmarium, 8. Closterium, 9. Pediastrum 10. Scenedesmus, 19. Ecidium, cluster-cups, 20. Peronospora infestans, the potato fungus, 21. Peronospora infestans, in section of potato leaf, 22. Oidium, the vine fungus, 23. Erysiphe, the pea fungus, 24. Cells, showing alteration of form by pressure, 25. Parenchyma, 26. Sclerenchyma, 27. Fibro-vascular bundles, 28. Fibro-vascular bundles, 29. Bast and wood cells, . 30. Dotted cells, . PAGE 3 9 9 9 ΙΟ II 12 15 16 17 17 19 20 22 22 25 26 26 26 26 27 27 27 27 27 28 29 29 57. Primrose, short-styled form, FIG. 37. Fuchsia, showing parts of a flower. calyx, Co. corolla, Sta. stamens, Pi. pistil, 38. Cowslip, showing Calyx and Corolla, 39. Stamen of Crocus, 40. Pollen grains, 41. Pistil. Stg. stigma, Sty. style, Ov. ovary, 42. Pistil, section. Oie, ovules, 43. Ovary of Primrose, cross and vertical sections, 44. Pollen grain (pg) and tube (pt), 45. Stigmas of (a) Wheat and (6) Hop. (After Axell), 46. Stigmas of (a) Primrose, (b) Heath, 47. Section of Arum maculatum, 48. Pink with anthers. (After Lubbock), 49. Pink with stigmas. (After Lubbock), 50. Pansy, section, 51. Stigmas of Geranium pratense, 52. Lupinus heterophyllus, 53. Lupinus heterophyllus, 54. Lupinus heterophyllus, PAGE Re. receptacle, Ca. anthers, 58. Feverfew (Chrysanthemum parthenium), a single floret, 59. Feverfew (Chrysanthemum parthenium), section of ring of 60. Feverfew (Chrysanthemum parthenium), mature stigmas, 61. Campanula. (After Lubbock), 62. Campanula, 48 50 50 50 51 51 51 52 53 67. Orchis maculata, section with Bee. (After Hooker), 53 53 53 55 55 72. Dionea muscipula, Venus's Fly-trap, 73. Drosera rotundifolia, Round-leaved Sundew, 74. Drosera rotundifolia, leaf, 55 62 75. Pinguicula vulgaris, the Butterwort, 63 76. Cereus, a Cactus, 64 77. Opuntia, the Indian Fig, or Prickly Pear, 69 83. Cephalotus follicularis, the Australian pitcher-plant, 84. Heliamphora nutans, 77 78 78 FIG. 85. Dipsacus sylvestris, the Common Teazle, 86. Rafflesia Arnoldi, 87. Mantisia, or Dancing Girls, 88. Orchis mascula, enlarged, 95. Sporangia of Fern, 96. Germination of Fern-spores, 97. Polypodium vulgare, the Common Polypody, 104. Polytrichum commune, Antheridia, (a) antherozoids, 105. Two-horned Scale-moss, Sporange, 106. Spores and elaters of Scale-moss, 107. Forked Scale-moss, Calyptra or hood, 108. Flat-leaved Scale-moss, Calyx, 144 144 116. Equisetum sylvaticum, disc with sporangia, 109. Marchantia polymorpha, Antheridia, 110. Marchantia polymorpha, Antheridia, section, 115. Equisetum sylvaticum, the Wood Horsetail, 117. Equisetum sylvaticum, a Sporange, 165 118. Equisetum sylvaticum, spore with elaters coiled, 165 119. Equisetum sylvaticum, spore with elaters uncoiled, 165 120. Chara, a Stonewort, 167 121. Chara, enlarged, 167 122. Chara, longitudinal section of stem, 168 137. Mucor, conjugation, 138. Mucor, Zygospore, 139. Development of an Agaric, 140. Section of an Agaric, 141. Basidia and spores of an Agaric, 142. Peronospora infestans, the potato fungus, 143. Peronostora infestans, in section of leaf, 144. Acidium, Cluster cups, 145. Oidium, the Vine fungus, 146. Erysiphe, the Pea fungus, 147. Cyathus vernicosus, or Bird's-nest fungus, 148. Protococcus, 149. Section of Fucus vesiculosus, 150. Conceptacle of Fucus vesiculosus, 151. Fucus nodosus, 152. Padina pavonia, 153. Plocamium coccineum, NOTE.-Figs. 93, 95, 96, 97, 98, 99, 100, are from "Ferns and Ferneries." PLANT-LIFE. CHAPTER I. MICROSCOPIC PLANTS. NOT the least among the discoveries which we owe to the microscope is the existence of an extensive, though exceedingly minute, world of animal and plant life. No matter where we look, we shall find members of this hitherto invisible world absolutely swarming around us. The very air we breathe is filled with minute forms of life; and in the water we drink we are certain to find many of them, unless it has been boiled or filtered. Any sweet fluid which has been exposed to the air for a few hours will teem with them; so will water in which any vegetable or animal matter has been infused. Some are so exceedingly small that 20,000 of them placed side by side would not cover the length of an inch. Very expensive and finely-adjusted instruments are, of course, required to enable us to see organisms so extremely minute; but there are hundreds of interesting forms which may be clearly seen by simpler and less expensive instruments. One of the best A |