S36 



INDEX. 



221 ; osmotic researches, 123 n.; 

 on permeability of membranes, 

 88; on rigidity of pulvinus of 

 Oxalis, 206; on root-tip being 

 sensitive to gravitation, 160 n. ; 

 on sensitiveness of Oxalis leaves, 

 205; method of applying con- 

 tinued stimulation to Mimosa, 

 205 ; on stomata and intercellu- 

 lar spaces, 107 n. ; modification 

 of Velten's hot-stage, 17 n. 



Phajus, leucoplasts of, 34 



Phalaris, heliotropism of, 180, 183 



Phaseolus, twining of, 229; water 

 exuded by leaves of, 75 



Phenol, poisonous effect on Oxalis, 

 19 



Phillips, see Darwin, F. and Phillips 



Phloroglucin, 269, 271 



Phlox, assimilation of sugar by 

 flowers of, 33 



Phosphoric acids, see Acids 



Phosphorus, used to demonstrate 

 evolution of oxygen, 41 ; neces- 

 sity of in water-culture, 62, 65 



Phycomyces, curvature of towards 

 iron, 212; observation on growth 

 of, 152, 161 ; growing downwards 

 heliotropically, 182 



Pigment, of Florideae, 53 ; of Poly- 

 siphonia, 53 



Pigments, of Kicinus, Amaranthus, 

 52 



Pinguicula, epinastic leaves of, 198 



Pinot's experiment on geotropic 

 roots, 167 



Pinus, appearance of chlorophyll 

 in, 54 



Pisum used in experiments on 

 enzymes, 306 



Pith, extension of in water, 134 



Plantago, epinastic leaves of, 198 ; 

 pollen of for chemotaxis, 217 



Plasmolysis, microscopic observa- 

 tion of, 125; recovery from, 

 125 ; in relation to growth, 148 



Plastic substances, methods of in- 

 vestigating, introductory re- 

 marks, 238; general literature 

 of, 239 ; detection and estimation 

 of, 239 



Platanus for diffusion experiment, 

 49 



Polariscope, 119 



Pollen, chemotaxis of, 216 



Polyanthus, elasticity of flower 

 stalk of, 137 



Polygon atum used for negative 

 pressure experiments, 87 



Polysiphonia, pigment of, 53 



Populus, for cobalt method, 105 



Potamogeton used in assimilation 

 experiments, 24, 32; evolution 

 of gas by, 34 



Potassium, necessity of in water- 

 culture, 62, 64, 70 



Potato used in experiments on 

 starch, 294 ; on ash, 302 



Potometer, 79 



Pressure, hydrostatic in turgescent 

 tissues, 130, 131 ; negative, 86, 

 87 ; producing recovery of flaccid 

 shoot, 90; produced by roots, 

 74 



Primula sinensis, stomata of, 107 



Proctor on Tannins, 266 



Proteids, 249 ; practical classifica- 

 tion of, 250; extraction of, 244, 

 245; qualitative tests for, 251, 

 252; separation from peptones 

 and albumoses, amides, etc., 252 ; 

 estimation of, 254; experiments 

 on, 259, 260, 312, 313, 315, 321, 

 322 



Protoplasm, circulation of, effect 

 of heat on, 16; circulation of 

 affected by chloroform, 19; af- 

 fected by C0 2 , 18; affected by 

 induced current, 20 



Prunus padus for assimilation ex- 

 periments, 26 



Puccinia, culture of, 70 



Pulvinus, tension in, 141 ; of Oxalis, 

 rigidity of, 206, 207 



Pyrogallate, for gas analysis, 47 n. 



Pyrus communis, for cobaltmethod, 

 105 n. 



Eanunculus ficaria, stomata of, 



107, 110 

 Reagents used in experiments on 



metabolism, 323 



