378 



INDEX 



Pigments, respiration, 271-272 



yellow, physiological importance 

 of, 21-22 

 Plasma membrane, 117-118 



permeability of, 112-113, 123-124 

 Plasmolysis, 112-116 



of cells, 113 



temporary, 116-119 

 Plastids, 17-18 



green, 17 

 Polarity, 358-362 

 Pollen development, 353-354 

 Pollination, 353 

 Polysaccharides, enzymatic splitting 



of, 206-209 

 Popoff, on growth stimulants, 309- 



310 

 Porodko, on chemotropism, 331 

 Porometer, Darwin's, 168 

 Potassium, role in metabolism, 73 

 Potometer, 160 



Sachs', 147 

 Precipitation membranes, 110 

 Presentation time, in phototropic re- 

 sponse, 321 

 Prianishnikov, on ammonia, 228 



on asparagine, 227 



on nitrogen fertilizers, 55 



on pot culture, 81 



on proteins, 224-225 



on root absorption, 79 



on soil acidity, 79 



on transformation of substances in 

 seed germination, 248-249 

 Priestley, on root pressure, 143 



on water absorption, 141-142 

 Proferments, 215 

 Prolamines, 223 



Propagation, by cuttings and layers, 

 358-362 



role and methods of, 356-358 



vegetative, 356 

 Proteases, 224-225 

 Protection against freezing, 126-129 

 Proteins, classification of, 229-230 



constitution of, 229-230 



dectection of, 220 



enzymatic destruction of, 224-228 



Proteins, grouping of, 223-224 

 in protoplasm, 228-231 

 reserve, products of hydrolysis of, 



219-224 

 synthesis of, 228-231 

 in plants, 231 

 Proteolytic enzymes, 224-225 

 Protoplasm, changes in colloidal state 

 of, 123-124 

 chemical composition of, 230 

 coagulation and death of, 123-124 

 Protoplasmic membrane, composi- 

 tion and structure of, 116-119 

 permeability to different substances 

 of, 116-119 

 Purievitsch, on carbon dioxide de- 

 composition, 31-32 



R 



Raulin, on growth stimulants, 309 

 on nutrition of molds, 236 



Reaction time, in phototropic re- 

 sponse, 321 



Reciprocal effect, of stock and scion, 

 364, 365 



Reductase, 271 



Regeneration, 358-362 



Renner, on rise of water, 190, 192 



Reproduction, 342-362 



antagonism between vegetative 

 growth and, 345 



Reserve substances, major groups of, 

 199-202 



Respiration, 248-278 

 anaerobic, 258-261 

 chemistry of, 270-275 

 chromogens, 271-272 

 coefficient, 253-255 

 compensation point in, 277 

 effect of oxygen supply, 277 

 effect of temperature on, 276 

 enzymes, 270-271 

 hydrogen acceptors in, 272 

 influence of external and internal 



factors on, 275-278 

 inorganic substances in, 255-258 

 intensity and localization, 251-253 

 methods of study of, 251-253 



