yi LIFE MOVEMENTS IN PLANTS 



XLI.— MECHANICAL AND ELECTRICAL RESPONSE OF ROOT 

 TO VARIOUS STIMULI. 



PAGE. 



Mechanical and electrical response to Direct stimulation — 

 Mechanical and electrical response to Indirect stimula- 

 tion — Effect of unilateral stimulation applied at tlie root- 

 tip 4fil 



XLII.— GEO-ELECTRIC RESPONSE OF ROOT. 



Geo-electric response of the root-tip — Electric response in 

 the growing region of root — Differential effect between 

 tiie tip and the growing region — Geo-perception at the 

 root-tip .......... 467 



XLIIL— LOCALISATION OF GEO-PERCEPTIVE LAYER BY 

 .MEANS OF THE ELECTRIC PROBE. 



Principle of the method of electric exploration — The 

 Electric Probe — Electric exploration of the geo-percep- 

 tive layer — Geo-electric reaction at different depths of 

 tissues — Microscopical examination of the maximally 

 excited layer — Influence of season on geo-electric 

 response — Tests of insensitive specimens — Reaction at 

 lower side of the organ — The Method of Transverse 

 Perforation 478 



XLIV.— ON GEOTROPIC TORSION. 



Arrangement for torsional response — Algebraical summation 

 of geotropic, and phototropic effects — Balance of geo- 

 tropic by phototropic action — Comparative balancing- 

 effects of white and red lights — Effect of coal gas 

 on photo-geotropic balance ...... 503 



