LIST OF ILLUSTRATIONS. ix 



67. Pollen Grains : 1. Musk-Flower. 2. Wild Cucumber. 

 3. Marsh-Mallow. 4. Lily. 5. Chicory. 6. Pine. 



7. Evening Primrose. (After Gray) ... 81 



68. Grass Flower. The Feather-like Stigmas . . 85 



69. Vallisneria or Eel-Grass 87 



70. Section of Flower of Figwort 89 



71. Sections of the Two Klinds of Flowers of Partridge- 



berry 91 



72. Laurel Flower 92 



73. Pea Flower 92 



74. Hidden Flowers of the Hooded Violet . . .95 



75. Elm 98 



76. Alder .99 



77. Apple 100 



78. Honeysuckle 102 



79. Galium 103 



80. Larch .103 



81. Pine . . . 103 



82. Clematis Leaf 107 



83. Echinocystis or Wild Cucumber . . . .113 



84. Virginia Creeper 117 



85. Sarracenia or Pitcher Plant 119 



86. Darlingtonia Californica 123 



87. Drosera or Sundew 126 



88. Dion«a or Venus' Fly-Trap 129 



89. Lemnas 130 



90. A Lemna enlarged 130 



91. Wolffia. A, natural size; B, much magnified; C, 



cross-section of plant in flower .... 131 



92. Witch-Hazel 134 



93. Seed-Pod of Witch-Hazel 134 



94. Fruit of Thistle with Pappus 138 



95. Young Squash Plant 140 



96. Squash Plant, showing Manner of Growth of Stem 



and Roots • -141 



97. Root-Hairs 147 



98. Sucker-like Roots of Parasite 151 



99. Pocket Lens 154 



100. Reading-Glass . < . . . • . • .155 



