INDEX 



551 



Prickly leaves, 416*, 417* 



Primary root, 6*, 12*, 16*, 19 



Primitive flowers, 393 



Procambium, 65* 



Products, plant. See Plant products 



Pro-embryo, 144, 145* 



Promycelium, 259*, 261*, 271 



Propagation by roots, 436 



Propagation of plants, 436-446* 



Prosenchyma, 64 



Protection of plants from animals, 



413-419* 

 Protection of pollen, 426, 427, 434*, 



435 



Proteids, 9*, 11*, 25 

 Prothallial cell, 322*, 323, 335*, 368*, 



372*, 373 



Prothallium, 315-317* 

 Protobasidiomycetes, 258-264* 

 Protococcales, 179, 184* 

 'Protonema, 294* 

 Protoplasm, 34, 35*, 112, 156-168* 

 Protoplasm, characteristics of, 34- 



36 



Protoplasm, circulation of, 202 

 Protoplasm, continuity of, 99, 214 

 Protoplasm, structure of, 157 

 Protoplast, 34, 35*, 161 

 Protosiphon, 200* 

 Protozoa, 157 

 Pteridophyta, 306-344* 

 Pteridophytes, 306-344* 

 Pteridophytes, evolution of, 343 

 Pteridophytes, origin of, 342 

 Pteridophytes, summary of, 343, 344 

 Pteridospermae, 392 n. 

 Ptomaines, 232, 236 

 Public health, 236, 237 

 Puccinia, 260-263* 

 Puffball, 268* 

 Pulsating vacuole, 158* 

 Pulvinus, 99* 

 Pyrenoid, 160*, 162 

 Pythium, 247 



Race, 504 



Raceme, 133* 



Radial symmetry, 123*, 125, 126*, 



138* 



Radiating stems, 51 

 Radishes, competition among, 449* 

 Rainfall, 481, 488, 489* 

 Raspberry, 436*, 445* 

 Ray flowers, 134*, 135* 

 Ray, medullary, 60*, 66, 71, 72 



Receptacle, 123*, 125*, 130* 

 Receptacle of brown algae, 210*, 212 

 Receptacles of Marchantia, 282*, 



284* 



Red algae, 213-220* 

 Red algse, life habits of, 214, 215 

 Red algae, summary of, 219, 220 

 Red clover, leaf of, 98* 

 Red snow, 182 

 Regions of vegetation, 481 

 Reindeer moss, 257* 

 Reproduction, 35 

 Reproduction in flowering plants, 



138-145*, 436-446* 

 Resin duct, 366* 

 Respiration, 107, 110-115 

 Resting buds, 80 

 Resting condition, 112 

 Resurrection moss, 333 

 Retuse, App. I 

 Rhizoids, 280*, 281* 

 Rhizopus, 240, 241* 

 Rhodophyceae, 213-220* 

 Rhubarb roots, 26* 

 Ricciales, 279, 280* 

 Ricciocarpus, 280* 

 Rigid tissue, 312, 313. See Scleren- 



chyma 



Ring, annual, 66*, 68* 

 Ringent, App. II 

 Rise of water in stems, 73-75* 

 Rockweeds, 210-212*, Plate IV 

 Rocky Mountain region, 490, 493. 



494 



Root, 6*, 12*, 13, 15-33* 

 Root absorption, 30 

 Root absorption and temperature, 30 

 Root, adaptation to work, 33 

 Root cap, 24* 

 Root climbers, 20*, 48 

 Root, dicotyledonous, section of, 25* 

 Root, fleshy, 23* 



Root hair, 15, 16*, 24, 25* 27*, 28 

 Root pressure, 29*, 30 

 Root sections, 24*, 25* 

 Root system, 26, 27 

 Root tubercles, 234* 

 Roots, absorbing surface of, 27 

 Roots, adventitious, 19 

 Roots, aerial, 19-21* 

 Roots, brace, 21* 

 Roots, fibrous, 23* 

 Roots, movements of young, 30, 31 

 Roots, parasitic, 22*, 23 

 Roots, pine, lateral extension of, 32* 



