INDEX 
Photo-synthesis (Carbon assimila- 
tion), 11, 19, 23, 64, 71. 
Phycocyanin, 37. 
Phycoerythrin, 71. 
Phycomycetes (see also ‘‘ Alga- 
fungi’’), 81, 82, 85, 86,.92, 95, 99, 
288, Figs. 21, 22. 
Phyllodium, 271, 274. 
Phylloglossum, 146. 
Phyllosiphon, 85. 
Phytophthora infestans, 82. 
Pickerel-weed (Pontederia_ cordata) 
189, Fig. 46. 
Pigments, 22, 49, 64, 263, 274, 297; 
of Marine Algze, 64, 263. 
Pig-weed family (Chenopodiacez), 
208. 
Pine, Pinus, 169, 170, 227, 238, 245; 
P. contorta, 170, Fig. 42. 
Pineapple, P. family (see also 
‘*Bromeliaceze’’), 194, 198, 238. 
Pine-sap (Monotropa hypopitys) , 213, 
270, Figs. 52, 59. 
Pinguicula, 259. 
Pink, P. family (Caryophyllacez), 
209, 248. 
Pinnularia viridis, 65, Fig. 15. 
Piperinez (see ‘‘ Pepper’’). 
Pistia, 271. 
Pistil (see also ‘‘ Carpel’’), 179, 181, 
189, 190, 191, 194, 195, 197, 210, 213, 
215, 216, 245, 250, 253, 254, 256. 
Pisum, 210. 
Pitcher-plant (see also ‘‘ Darling- 
tonia,” ‘‘Nepenthes,” ‘‘Sarra- 
cenia”’), 205, 209, 258, Fig. 58. 
Placenta, 181, 206, 209. 
Plankton, 64. 
Plantain (Musa), 193; (Plantago), 
241, 251. 
Plasmodium, 23, 31, 32, 34, Fig. 4. 
Plastids (see also ‘‘ Chloroplast,” 
‘*Chromatophore’’), 6. 
Pleodorina Californica, 39, Fig. 6. 
Pleurococcus, 43, 47, Fig. 7. 
Pliocene formations, 227. 
Plum, 93, 165. 
Podophyllum, 236. 
Poinsettia, 210, 248. 
313 
Poisonous protective secretions, 260. 
Poison ivy (Rhus toxicodendron), 
237. 
Polar nuclei, 179. . 
Pollen, Pollen-spore, 28, 159, 160, 163, 
164, 165, 169, 170, 174, 178, 179, 180, 
181, 195, 203, 250, 251, 252, 253, 254, 
255, 256, 257, 294. 
Pollen-chamber (of Cycads), 163, 
Fig. 40, 
Pollen-sac, 159, 160, 169, 179, 202, 293, 
Figs. 40, 41, 42. 
Pollen-tube, 160, 163, 164, 169, 170, 
179, 180, 181, 292, Figs. 40, 42. 
Pollination, 28, 164, 169, 178, 180, 181, 
189, 190, 194, 206, 244, 245, 246, 247, 
248, 249, 250, 251, 252, 253, 254, 255, 
256; by birds, 249; by insects, 245, 
246, 247, 248, 249, 250, 251, 252, 253, 
254, 255, 256; by snails, 247. 
Pollinium, 195, 254, 255, 256, Fig. 56. 
Polycarpicee, 207, 208, 209, 218, 219, 
Fig. 50. 
Polygonacezx, 208. 
Polygonum, 206, Fig. 49. 
Polypodiacez, 138, 151, 
Polypodium, 135, 234; P. falcatum, 
135, Fig. 35. 
Polyporus, 87. F 
Polysiphonia, 72, 74, Figs. 19, 20. 
Pomegranate, 211. 
Pond-scum (see also ‘‘Conjugate,’’ 
“Spirogyra ’’), 59, 60, 85, Fig. 13. 
Pond-weeds (see also ‘‘Naiadacez’’), 
28, 178, 286, 198, Fig. 43. 
Pontederia, 189, Fig. 46. 
Poplar, 206, 228, 229, 230, 
Poppy, P. family (see also Esch- 
scholtzia,” ‘‘ Papaveraceg ’’), 209, 
241, 
Potassium, 2. 
Potato-fungus (Phytophthora infes- 
tans), 82. 
Prairies, 238, 241. 
Prickles, 28, 260, 295. 
Primrose, P. family (Primuline), 
213, 214. 
Procarp (of Rhodophycez), 74, 75, 
Fig. 20. 
