LOCALISATION OK (iKO-PERCEPTlVE LAYER 



497 



A curve constructed from the data given above is seen 

 in figure 177. The diameter of the flower stalk was 

 (v<S mm. The negative geo-electric reaction is seen to 

 undergo an increase till it attains a climax at the depth 

 of I-4 mm. It then undergoes a continuous diminution 

 till it becomes zero at the depth of '.I mm.; this neutral 

 zone extends through 1 mm. When the prol)e enters a 

 depth of 4*2 mm. measured from the upper side, it enters 

 a region affected by the pei'ceptive layer situated on the 

 under side, the opposite physiological reaction being indicat- 

 ed by induced electric change of galvanometric jjositivity. 



Fig. 177. Fig. 178. 



Fig. 177. — Curve of geo-electric excitation in dilTereut layers of Ni/mplKin. Ordi- 

 nate reprepents geo-electric excitation ; abscissa, distance from iipjier surface of tiower 

 stalk. The diagrammatic section underneath shows the position of geo-perceptive 

 layer (starch-sheath) corresponding to maximum induced galvanometric negativitv 

 and positivity on the two sides. 



Fig. 178. — The curve of geo-eiectric excitation m different layers of Hn/npln/lhnn. 



This positivity reaches a clima.K at a depth of 5-4 mm. 

 measured from tlu^ ui)per side, and 1-4 mm. when measured; 



