m 



LIS^E MOVEMENTS IN PLANTjS. 



The following is a tabular statement of the different 

 effects induced by Direct and Indirect stimulation. 



TABLE XXV. — SHOWIN'G UIFKERKNCE OF EFFECTS INDUCED BY DIRECT 

 AND INDIRECl' STIMTLATION. 



The results of investigations already described, enable 



us to formulate the general laws of tropic curvature 



applicable to all forms of stimuli, and to all types of 

 responding organs, pulvinated or growing. 



LAWS OF TROPIC CURVATURE. 



I, {a) DIRECT APPLICATION OP UNILATERAL STIMULUS 

 OF MODERATE INTENSITY, INDUCES A POSITIVE 

 OR CONCAVE CURVATURE, BY THE CONTRACTION 

 OF THE PROXIMAL AND EXPANSION OF THE 

 DISTAL SIDE. 



(h) UNDER STRONG OR LONG-CONTINUED STIMULATION, 

 THE POSITIVE CURVATURE IS NEUTRALISED OR 

 REVERSED, BY TRANSVERSE CONDUCTION OF EX- 

 CITATION ; THIS EFFECT IS ACCENTUATED BY 

 THE DIFFERENTIAL EXCITABILITY OF THE TWO 

 SIDES OF THE ORGAN. 



