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