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, PAGE 356778 IO II 12 15 16 17 17 19 20 22 22 25 26 26 26 27 27 27 27 27 28 29 29 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. Sg. stigma, Sty. style, Ov. ovary, 42. Pistil, section. Oie, ovules, PAGE Re. receptacle, Ca. 43. Ovary of Primrose, cross and vertical sections, 44. Pollen grain (pg) and tube (pt), 45. Stigmas of (a) Wheat and (b) Hop. (After Axell), 46. Stigmas of (a) Primrose, (b) Heath, . 47. Section of Arum maculatum, 48. Pink with anthers. 49. Pink with stigmas. 50. Pansy, section, (After Lubbock), (After Lubbock), 51. Stigmas of Geranium pratense, 54. Lupinus heterophyllus, 55. Lupinus heterophyllus, 63. Campanula, 64. Orchis maculata, enlarged, 65. Orchis maculata, Column, 56. Primrose, long-styled form, 57. Primrose, short-styled form, 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 51 51 52 (After Hooker), 69. Iris pseudacorus, the Flag, 70. Iris pseudacorus, 71. Iris pseudacorus, 66. Orchis maculata, Pollinia, 67. Orchis maculata, section with Bee. (After Hooker), 68. Bees with Pollinia. 72. Dionea muscipula, Venus's Fly-trap, 73. Drosera rotundifolia, Round-leaved Sundew, 74. Drosera rotundifolia, leaf, 55 60 62 63 75. Pinguicula vulgaris, the Butterwort, 64 76. Cereus, a Cactus, 69 77. Opuntia, the Indian Fig, or Prickly Pear, 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, 89. Lizard Orchis, Orchis hircina, 95. Sporangia of Fern, 96. Germination of Fern-spores, 97. Polypodium vulgare, the Common Polypody, 98. Asplenium viride, the Maidenhair Spleenwort, 99. Ceterach officinarum, the Scaly Spleenwort, 100. Ophioglossum vulgare, the Adder's-tongue, IOI. Lycopodium clavatum, Common Club-moss, 102. Polytrichum commune, Calyptra, PAGE 80 82 83 84 94 98 99 103 104 гюб 107 114 139 142 103. Polytrichum commune, Sporange, 142 104. Polytrichum commune, Antheridia, (a) antherozoids, 142 105. Two-horned Scale-moss, Sporange, 144 106. Spores and elaters of Scale-moss, 144 142. Peronospora infestans, the potato fungus, 143. Peronospora infestans, in section of leaf, 190 1,90 144. Ecidium, Cluster cups, 191 191 146. Erysiphe, the Pea fungus, 145. Oidium, the Vine fungus, 147. Cyathus vernicosus, or Bird's-nest fungus, 192 198 200 200 201 202 206 206 207 207 209 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 só 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 |