272 
Pistil, 143. 
Pistillate, containing pistils but not 
stamens. 
Pistil, parts of, 146, 147. 
Pitcher plant, 104, 105. 
Pith, 54. 
Pod, 187. 
Poisonous seeds, 25. 
Placenta, 147, 148. 
Plumule, 5. 
Pollarded trees, 84. 
Pollen, 146, 155, 156. 
Pollen-carrying apparatus, 162. 
Pollen, discharge of, 154, 155. 
Pollen-grains, 155. 
Pollen-grains, number of per ovule, 
159. 
Pollen, protection of, 166, 167. 
Pollen, protection of from rain, 
175, 176. 
Pollen tube, 155, 156. 
Pollen tubes, 156-158. 
Polypetalous, 146. 
Polysepalous, 146. 
Polytrichum, 2385-289, 
Pome, 193. 
Pondscum, study of, 221-224. 
Potash in hay, 117. 
Potato, 47, 73, 74. 
Potato seedling, 47, 49. 
Potato tuber, 73, 74. 
Prickly leaves, 103. 
Prickle, 208, 209. 
Primary root, 26, 29. 
Primrose, fertilization in flowers of, 
172, 178. 
Procambium, 65. 
Prosenchyma, 58. 
Protection of pollen, 166, 167. 
Proteids, 24, 74, 75. 
INDEX. 
Proteids, tests for, 24, 25, 75. 
Prothallium, 242. 
Protonema, 238. 
Protococcus, study of, 219-221. 
Protoplasm, 36, 37, 122. 
Protoplasm, characteristics of, 
128-130. 
Protoplasm, circulation of, 129, 150. 
Protoplasm, continuity of, 56. 
Pteridophytes, 216. 
Race, 214. 
Raceme, 152. 
Radial section, 56. 
Raspberry, 195. 
Ray, medullary, 31, 53. 
Ray-flowers, 134. 
Receptacle, 144, 145. 
Reflexed, turned down or under. 
Regular flowers, 143. 
Reproduction in alge, 225, 226. 
Reproduction in ferns, 245. 
Reproduction in flowering plants, 
158-160. , 
Reproduction in fungi, 235. 
Reproduction in Mosses, 256-239. 
Resin-passage, 60. 
Respiration, 128, 124. 
Retuse, 86. 
Rhachis, 241. 
Rhizopus, 230-252. 
Ring, annual, 55. 
Ringent, 148. 
Rise of water in stems, 66, 68, 69. 
Rockweed, 225, 226. 
Root, 26-87. 
Root-cap, 14, 15. 
Root-climbers, 45. 
Root-hair, 12, 15, 35-87. 
Root pressure, 37, 71. 
