INDEX 



375 



Oil, 18, 19. 



Oil, essential, 21. 



Oil, extraction, 18, 19. 



Oil, testing seeds for, 19, 20. 



Onion, bulb of, 59. 



Onion leaf, section of, *61. 



Onion, structure of, 84, 85. 



Onion, tests for food-materials in, 



85. 

 Onoclea, *286. 

 Oogonia, *226, *229, *232. 

 Oosphere, *232. 

 Opposite, 51, *52, 106, *107, *108, 



*109. 

 Oranges, 329. 330. 

 Orbicular, App. I, *355. 

 Orchid, aerial roots of an, 30. 

 Organs, essential, *148. 

 Organs, vegetative, 24, 25. 

 Ornamental plants, 342. 

 Oscillatoria, type study, 216-218*. 

 Osmosis, 45^7*. 

 Osmosis in an egg, 45, *46. 

 Osmosis in root-hairs, *46, 47. 

 Ovary, *154-156. 

 Ovate, App. I, *355. 

 Ovoid, egg-shaped, like the spores 



in Fig. 182. 

 Ovule, 153, *154. 

 Ovule, spruce, fertilized, *302. 

 Ovule, structure of, *166. 

 Oxalis leaf, development of, *94. 

 Oxidation, 10. 

 Oxygen, 10, 136. 

 Oxygen making, 137. 



Palisade-cells, *128. 

 Palmate, 100, *102, 103. 

 Pampas region, 204. 

 Panicle, *193, App. I, *359. 



Pansy, leaf-like stipules of, *101. 



Fapihonaceous corolla, *150. 



Papillae on stigma of a lily, *165. 



Parasites, 32, *33. 



Parasitic roots, 32, *33. 



Parietal placenta, *155. 



Parsnip root, study of, 37, 38. 



Pea seed, *8, 12, *13. 



Pea seedling, mutilated, 12, *13. 



Pear buds, *91. 



Pear fruit spurs, *91. 



Pedicel, App. I, *357. 



Peduncle, App. I, 357. 



Peg of squash seedling, 23, 24. 



Peltate, App. I, *356. 



Pepo, 188. 



Perennial, 39, 54. 



Perianth, *148. 



Pericarp, 187. 



Perigynous, *156. 



Perisperm, 13. 



Petal, 143, 146, 148. 



Petiole, 98. 



Phanerogams, 209, 211. 



Phanerogams, classes of, 211. 



Phosphorus, 135. 



Phytopthora, «249. 



Pine, seedling, *28. 



Pinnse, leaflets of a pinnately com- 

 pound leaf, *103. 



Pinnate, *98, *99, *103. 



Pinnules, *244, 245. 



Pistil, 143-145, 147, *148, *151, 

 *153, 154. 



Pistil, parts of, *153. 



Pitcher-plant, *118, 120. 



Pith, *65, 6G, 67, *68, *70, »71, *72. 



Placenta, 154, »155. 



Plant breeding, 309*-323. 



Plant societies, 113, 114. 



