October 1919.
CONTENTS.
| [PART III.] TROPISM IN PLANTS. | |
| PAGE. | |
| XXII.—THE BALANCED CRESCOGRAPH. | |
| Principle of the Method of Balance—Compensatingmovement—Growth-scale—Sensitivenessof the CrescographicBalance—Effect of CO2—Effect of anæsthetics | [255] |
| XXIII.—ON TROPIC MOVEMENTS. | |
| Complexity of the problem—Contradictory nature ofresponses—Two classes of tropic responses—Longitudinaltransmission of effect of stimulus—Transverse transmissionof effect of stimulus—Modification of tropiccurvature by conducting power of tissues and differentialexcitability of the organ | [268] |
| XXIV.—TROPIC CURVATURE WITH LONGITUDINAL TRANSMISSIONOF EFFECT OF STIMULUS. | |
| Dual impulses, positive and negative, caused by stimulus—Directand Indirect stimulus—Tropic effect of Indirectstimulation | [271] |
| XXV.—TROPIC CURVATURE WITH TRANSVERSE TRANSMISSIONOF EFFECT OF STIMULUS. | |
| Turgor variation under transverse transmission ofstimulus-effect—Tropicresponses of pulvinated and growingorgans to unilateral stimulation—Direct unilateral stimulation—Indirectunilateral stimulation—Difference ofeffects induced by Direct and Indirect stimulation—Lawsof tropic curvature | [279] |
| XXVI.—MECHANOTROPISM: TWINING OF TENDRILS. | |
| Anomalies of mechanotropism—Effects of indirect anddirect electric stimulation on growth of tendril—Effectof direct and indirect mechanical stimulus—Immediateand after-effect of stimulus—Inhibitory action ofstimulus—Response of less excitable side of thetendril—Relative intensities of responses of upper andunder sides of tendril of Passiflora—Negative curvatureof tendril | [288] |
| XXVII.—ON GALVANOTROPISM. | |
| Polar effects of electric current on growth—Effect ofanode and cathode on growth | [301] |
| XXVIII.—ON THERMONASTIC PHENOMENA. | |
| Effect of temperature—Different thermonastic organs—Twotypes of response: Positive and Negative—Effect ofrise of temperature and of stimulus on thermonasticorgans—Law of thermonastic reaction | [305] |
| XXIX.—ON PHOTOTROPISM. | |
| Complexity of problem of phototropic reaction—Action oflight—Positive phototropic curvature of pulvinatedorgans—Positive phototropic curvature of growingorgans—Phenomenon of recovery—Immediate and after-effectof light on growth—Latent period of phototropicreaction—Growth variation induced by flash of lightfrom a single spark—Maximum positive curvature undercontinued action of light | [313] |
| XXX.—DIA-PHOTOTROPISM AND NEGATIVE PHOTOTROPISM. | |
| Differential excitability of two halves of pulvinus ofMimosa—Transformationof positive to negative curvature—Tropiceffect under sunlight—Negative phototropism ofshoot and root | [328] |
| XXXI.—RELATION BETWEEN THE QUANTITY OF LIGHT ANDTHE INDUCED PHOTOTROPIC CURVATURE. | |
| Effect of increasing intensity of light on pulvinated andgrowing organs—Effect of increasing angle—Effect ofduration of exposure | [338] |
| XXXII.—THE PHOTOTROPIC CURVE AND ITS CHARACTERISTICS. | |
| Summation of stimulus—General consideration—The generalcharacteristic curve—Characteristics of simple phototropiccurve—Variation of susceptibility for excitation indifferent parts of the curve—Effect of sub-minimalstimulus—The complete phototropic curves of pulvinatedand growing organs—Limitation of Weber's law | [346] |
| XXXIII.—TRANSMITTED EFFECT OF PHOTIC STIMULATION. | |
| Effect of light applied on tip of Setaria—Response ofgrowing region to unilateral stimulus—Effect of simultaneousstimulation of the tip and the hypocotyl—Algebraicalsummation of effects of direct and indirectstimuli | [362] |
| XXXIV.—ON PHOTONASTIC CURVATURES. | |
| Phototropic response of anisotropic organs—Positivepara-heliotropism—Negative para-heliotropism—Responsesof pulvinated and growing organs to light | [378] |
| XXXV.—EFFECT OF TEMPERATURE ON PHOTOTROPICCURVATURE. | |
| Effect of temperature on excitability—Effect of temperatureon conduction—Phototropic response of tendrils—Seasonalvariation of phototropic curvature—Antagonisticeffects of light and of rise of temperature | [388] |
| XXXVI.—ON PHOTOTROPIC TORSION. | |
| Torsional response to light—Effect of different modesof lateral stimulation—Effect of differential excitabilityon the direction of torsion—Laws of torsionalresponse—Complex torsion under light—Advantages ofthe Method of Torsional Response—The TorsionalBalance—Determination of the direction of stimulus | [397] |
| XXXVII.—RADIO-THERMOTROPISM. | |
| Effect of infra-red radiation—Positiveradio-thermotropism—Dia-radio-thermotropism—Negativeradio-thermotropism | [410] |
| XXXVIII.—RESPONSE OF PLANTS TO WIRELESS STIMULATION. | |
| Effects of different rays of spectrum on growth—Thewireless system—Mechanical and electrical responses ofMimosa to Hertzian waves—Effect of wireless stimulationon growth of plants | [416] |
| XXXIX.—GEOTROPISM. | |
| Direction of the stimulus of gravity—The GeotropicRecorder—Determination of the character of geotropicreaction—Theory of statoliths—Determination of thelatent period—The complete geotropic curve—Determinationof effective direction of stimulus of gravity—Algebraicalsummation of effects of geotropic and photicstimulus—Analogy between the effects of stimulus oflight and of gravity—Relation between the directiveangle and geotropic reaction—Differential geotropicexcitability | [425] |
| XL.—GEO-ELECTRIC RESPONSE OF SHOOT. | |
| Electric response to direct and indirect stimulation—Experimentalarrangement for obtaining geo-electricresponse—Geo-electric response of the upper and lowersides of the organ—Method of Axial Rotation—Characteristicsof geo-electric response—Physiological characterof geo-electric response—Effect of differential excitabilityof the organ—Law determining the relation betweenangle of inclination and geotropic effect—Method ofVertical Rotation—Electric response through an entirecycle—Relation between angle of vertical rotation andintensity of geo-tropic reaction | [442] |
| XLI.—MECHANICAL AND ELECTRICAL RESPONSE OF ROOTTO VARIOUS STIMULI. | |
| Mechanical and electrical response to Direct stimulation—Mechanicaland electrical response to Indirect stimulation—Effectof unilateral stimulation applied at the root-tip | [461] |
| XLII.—GEO-ELECTRIC RESPONSE OF ROOT. | |
| Geo-electric response of the root-tip—Electric response inthe growing region of root—Differential effect betweenthe tip and the growing region—Geo-perception at theroot-tip | [467] |
| XLIII.—LOCALISATION OF GEO-PERCEPTIVE LAYER BYMEANS OF THE ELECTRIC PROBE. | |
| Principle of the method of electric exploration—TheElectric Probe—Electric exploration of the geo-perceptivelayer—Geo-electric reaction at different depths oftissues—Microscopical examination of the maximallyexcited layer—Influence of season on geo-electricresponse—Tests of insensitive specimens—Reaction atlower side of the organ—The Method of TransversePerforation | [478] |
| XLIV.—ON GEOTROPIC TORSION. | |
| Arrangement for torsional response—Algebraical summationof geotropic, and phototropic effects—Balance of geotropicby phototropic action—Comparative balancingeffects of white and red lights—Effect of coal gason photo-geotropic balance | [503] |
| XLV.—ON THERMO-GEOTROPISM. | |
| Necessary conditions for geotropic curvature—Modifyinginfluence of temperature on geotropic curvature—Magneticanalogue—Tropic equilibrium under varyingintensities of stimulus—Effect of variation of temperatureon geotropic torsion—Variation of apo-geotropiccurvature under thermal change—Effect of variationof temperature on dia-geotropic equilibrium | [509] |
| [PART IV.] NIGHT AND DAY MOVEMENTS IN PLANTS. | |
| XLVI.—DIURNAL MOVEMENTS IN PLANTS. | |
| Complexity of the problem—The different factors involved—Autonomousmovements—Epinasty and hyponasty—Positiveand negative thermonasty—Thermo-geotropism—Classificationof diurnal movements—Discriminatingtests for classification—Diurnal variationof light and of temperature | [523] |
| XLVII.—DIURNAL MOVEMENT DUE TO ALTERNATION OFLIGHT AND DARKNESS. | |
| Experimental arrangements—The Quadruplex NyctitropicRecorder—Diurnal movement of the leaflet of Cassiaalata—Effect of variation of temperature—Effect ofvariation of light—Diurnal movement of the terminalleaflet of Desmodium gyrans—The 'midday sleep' | [535] |
| XLVIII.—DIURNAL MOVEMENT DUE TO VARIATION OFTEMPERATURE AFFECTING GROWTH. | |
| Tropic and nastic movements—Distinction between thermonasticand thermo-geotropic action—Diurnal movementof Nymphæa—Action of light—Effect of variation oftemperature | [546] |
| XLIX.—DAILY MOVEMENT IN PLANTS DUE TO THERMO-GEOTROPISM. | |
| Characteristics of thermo-geotropic movements—Diurnalmovement of Palm trees—Diurnal movement of procumbentstems and of leaves—Continuous diurnal recordfor successive thermal noon—Modification of the diurnalcurve—Effect of fluctuation of temperature—Effect ofrestricted pliability of the organ—Effect of age—Effectof season—Reversal of the normal rhythm—Effectof constant temperature—Diurnal movement ininverted position | [554] |
| L.—THE AFTER-EFFECT OF LIGHT. | |
| Electric after-effect of light—After-effect at pre-maximum,maximum, and post-maximum—Tropic response underlight, and its after-effects at pre-maximum, maximum,and post-maximum | [569] |
| LI.—THE DIURNAL MOVEMENT OF THE LEAF OF MIMOSA. | |
| Four different phases in the diurnal record ofMimosa—Different factors determining its diurnal movement—Diurnalvariation of geotropic torsion—Autonomouspulsation of the leaf of Mimosa—ThePhotometric Recorder—Effect of direct light—Theevening spasmodic fall of the leaf—Diurnal movementof the amputated petiole—Diurnal curve of the petioleof Cassia alata—Response of Mimosa to darkness atdifferent parts of the day—After-effect of light atpre-maximum, maximum, and post-maximum | [576] |
ILLUSTRATIONS.
| FIGURE. | PAGE. | |
| 93. | Arrangement for compensation of growth-movement by equal subsidence of plant-holder | [257] |
| 94. | Photograph of the Balanced Crescograph | [258] |
| 95. | Balanced Crescographic record | [260] |
| 96. | Record showing the effect of CO2 | [265] |
| 97. | Effect of ether and of chloroform | [266] |
| 98. | Diagrammatic representation of effects of Indirect and Direct stimulation | [275] |
| 99. | Tropic curvature of Crinum | [276] |
| 100. | Turgor variation caused by Indirect stimulation | [281] |
| 101. | Response of Mimosa leaf under transverse transmission of effect of electric stimulus | [282] |
| 102. | Diagrammatic representation of Indirect and Direct stimulation of tendril | [290] |
| 103. | Record by Method of Balance | [291] |
| 104. | Variation of growth under direct stimulation | [292] |
| 105. | Positive curvature of tendril of Cucurbita | [295] |
| 106. | Diagrammatic representation of effects of Indirect and Direct unilateral stimulation of tendril | [296] |
| 107. | Retardation of rate of growth under cathode | [303] |
| 108. | Acceleration of rate of growth under anode | [303] |
| 109. | Thermonastic and radionastic responses of petal of Zephyranthes | [308] |
| 110. | The Thermonastic Recorder | [309] |
| 111. | Negative thermonastic response of Nymphæa | [310] |
| 112. | Successive positive responses of the terminal leaflet of bean plant | [317] |
| 113. | Positive response and recovery under moderate phototropic stimulation | [318] |
| 114. | Persistent positive curvature under stronger stimulation | [318] |
| 115. | Immediate and after-effect of stimulus of light on growth | [320] |
| 116. | Latent period for photic stimulation | [324] |
| 117. | Effect of a single electric spark on growth | [325] |
| 118. | Responses of Mimosa leaf to light from above | [330] |
| 119. | Responses of Mimosa leaf to light from below | [330] |
| 120. | Record of effect of continuous application of light on upper half of pulvinus of Mimosa | [331] |
| 121. | Positive and negative phototropic response of Oryza | [335] |
| 122. | Leaf of Desmodium gyrans | [339] |
| 123. | The Oscillating Recorder | [340] |
| 124. | Tropic effect of increasing intensity of light on the leaflet of Desmodium gyrans | [341] |
| 125. | Tropic effect of increasing intensity of light on growing organ (Crinum) | [341] |
| 126. | The Collimator | [342] |
| 127. | Effect of angle of inclination of light on tropic curvature of pulvinated organ | [343] |
| 128. | Effect of angle of inclination on growth-curvature | [343] |
| 129. | Effect of increasing duration of exposure to light | [344] |
| 130. | Effect of continuous electric and photic stimulation on rate of growth | [348] |
| 131. | Characteristic curve of iron | [351] |
| 132. | Simple characteristic curve of phototropic reaction | [351] |
| 133. | Complete phototropic curve of pulvinated organ | [358] |
| 134. | Complete phototropic curve of growing organ | [359] |
| 135. | Arrangement for local application of light | [367] |
| 136. | Response of seedling of Setaria to light | [368] |
| 137. | Effect of application of light to the growing hypocotyl of Setaria | [370] |
| 138. | Response to direct and indirect photic stimulus | [373] |
| 139. | Diagrammatic representation of the effects of direct and indirect stimulation of Setaria | [375] |
| 140. | Photonastic curvature of creeping stem of Mimosa pudica | [380] |
| 141. | Positive phototropic response of Erythrina indica | [382] |
| 142. | Response of leaflet of Mimosa to light | [383] |
| 143. | Response of leaflet of Averrhoa to light | [383] |
| 144. | Diagrammatic representation of different types of phototropic response | [384] |
| 145. | Phototropic curvature of tendril of Passiflora | [392] |
| 146. | Effect of rise of temperature on phototropic curvature | [394] |
| 147. | After-effect of rise of temperature | [395] |
| 148. | Arrangement for record of torsional response | [399] |
| 149. | Record of torsional response of pulvinus of Mimosa pudica | [400] |
| 150. | Leaflets of Cassia alata | [404] |
| 151. | Positive response to thermal radiation | [413] |
| 152. | Record of positive, neutral, and reversed negative curvature under thermal radiation | [414] |
| 153. | Diagrammatic representation of the wireless system | [419] |
| 154. | Mechanical response of Mimosa leaf to electric waves | [420] |
| 155. | Electric response of Mimosa to Hertzian wave | [420] |
| 156. | Record of responses of growing organs to wireless stimulation | [422] |
| 157. | The Quadruplex Geotropic Recorder | [428] |
| 158. | Effect of alternate application of cold on upper and lower sides of the organ | [430] |
| 159. | Geotropic response of flower stalk of Tube-rose | [433] |
| 160. | Geotropic response of Tropæolum | [433] |
| 161. | The Complete Geotropic Curve | [435] |
| 162. | Diagrammatic representation of photic and geotropic stimulation | [436] |
| 163. | The effect of super-imposition of photic stimulus | [436] |
| 164. | Diagrammatic representation of the mechanical and electrical response | [443] |
| 165. | Diagrammatic representation of geo-electric response | [447] |
| 166. | Diagrammatic representation of Methods of Axial and Vertical Rotation | [449] |
| 167. | Diagrammatic representation of the geo-electric response of the shoot | [450] |
| 168. | Geo-electric response of the petiole of Tropæolum | [452] |
| 169. | Geo-electric response of the scape of Uriclis | [453] |
| 170. | Mechanical and electric response to indirect stimulation | [463] |
| 171. | Diagrammatic representation of mechanical and electric response of root | [464] |
| 172. | Diagrammatic representation of geo-electric response of root-tip | [469] |
| 173. | Diagrammatic representation of geo-electric response of growing region of root | [471] |
| 174. | Diagrammatic representation of the geo-perceptive layer | [480] |
| 175. | The Electric Probe | [483] |
| 176. | Transverse section showing continuous geo-perceptive layer (Bryophyllum) | [488] |
| 177. | Curve of geo-electric excitation in different layers of Nymphæa | [497] |
| 178. | Curve of geo-electric excitation in Bryophyllum | [497] |
| 179. | Diagram of arrangement of geotropic torsional response | [503] |
| 180. | Additive effect of stimulus of gravity and light | [505] |
| 181. | Algebraical summation of geotropic and phototropic actions | [505] |
| 182. | Comparative balancing effects of white and red lights | [506] |
| 183. | Effect of coal gas on photo-geotropic balance | [507] |
| 184. | Diagram of magnetic balance | [511] |
| 185. | Effect of variation of light on phototropic equilibrium | [512] |
| 186. | Effect of variation of temperature on geotropic torsion | [514] |
| 187. | Simultaneous records of variation of temperature, on up and down movement, and of torsion of the leaf of Mimosa | [518] |
| 188. | Arrest of pulsatory movement of leaflet of Desmodium gyrans by light | [528] |
| 189. | Effect of unilateral light on hyponastic movement | [529] |
| 190. | The Nyctitropic Recorder | [537] |
| 191. | Effect of sudden darkness on leaflet of Casia alata | [539] |
| 192. | Diurnal movement of the leaflet of Cassia alata | [540] |
| 193. | The day and night position of the petiole and terminal leaflet of Desmodium gyrans | [541] |
| 194. | Diurnal record of the terminal leaflet of Desmodium gyrans | [542] |
| 195. | Photograph of closed flower of Nymphæa during day | [550] |
| 196. | Photograph of open flower of Nymphæa at night | [550] |
| 197. | Action of light on the petal of Nymphæa | [551] |
| 198. | Diurnal movement of the petal of Nymphæa | [552] |
| 199. | Diurnal record of the Sijbaria Palm | [556] |
| 200. | Diurnal record of inclined Palm, geotropically curved procumbent stem of Tropæolum, and dia-geotropic leaf of Palm | [557] |
| 201. | Diurnal record of leaves of Dahlia, Papya, and Croton | [558] |
| 202. | Diurnal record of procumbent stem of Tropæolum, and leaf of Dahlia for two successive days | [560] |
| 203. | Abolition of the diurnal movement under constant temperature (Tropæolum) | [565] |
| 204. | Effect of inversion of plant on diurnal movement of Tropæolum | [567] |
| 205. | Electric response of the leaf stalk of Bryophyllum under light | [571] |
| 206. | Diagrammatic representation of electric after-effect of photic stimulation | [571] |
| 207. | After-effect of pre-maximum photic stimulation | [574] |
| 208. | After-effect of maximum photic stimulation | [574] |
| 209. | After-effect of post-maximum photic stimulation | [574] |
| 210. | Diurnal record of Mimosa in summer and winter | [577] |
| 211. | Record of diurnal variation of torsion in Mimosa leaf | [582] |
| 212. | Continuous record of automatic pulsation of Mimosa leaf | [585] |
| 213. | Photometric record showing variation of intensity of light from morning to evening | [586] |
| 214. | Record of leaf of Mimosa after amputation of sub-petioles | [589] |
| 215. | Diurnal record of Cassia leaf | [591] |
| 216. | Post-maximum after-effect of light on response of leaflet of Cassia | [592] |
| 217. | Effect of periodic alternation of light and darkness on response of Mimosa leaf | [594] |
| 218. | Pre-maximum after-effect of light in Mimosa | [595] |
| 219. | After-effect at maximum | [595] |
| 220. | Post-maximum after-effect exhibiting over-shooting below position of equilibrium | [595] |