410 CH. XXXVI. TORSION UNDER UNILATERAL STIMULATION 



actual reversal to — 4. Further rotation beyond this point 

 restored the direction of torsion to positive and the rate to 

 nearly the same value as when the plant was in the previous 

 position. The results are made clear by the following 

 tabular statement of the rates of torsion in four different 

 positions 90° apart— at 67°, 157°, 247°, and 337°. 



Table LIV. — Effects of Exposure of Different Sides (90° apart) 



TO Light (Porana). 



[Normal rate in dark — 30.] 



Different sides . 

 Rate of rotation 



67° (A) 

 61 



157' (N) 

 29 



247° (R) 

 - 4 



337° (NO 

 27 



A careful examination of the above results leads to the 

 following conclusions : 



1. The action of light on the different sides of the stem 



induced responsive torsional variations which are 

 very characteristic. 



2. Four different sides can be distinguished by their 



respective induced variations. Two of these, N 

 and N', at 157° and 337° in Table LIV, are neutral, 

 the rate of torsion having remained practically 

 the same as when in the dark. 



3. The two flanks, at right angles to the neutral sides, 



exhibited marked changes : the one (A), at 67°, 

 showed a maximum acceleration of 61 ; the other 

 (R), at 247°, showed a maximum retardation 

 culminating in actual reversal to — 4. 



I obtained numerous other results in confirmation of 

 the above : the following table gives a synopsis of the 

 effects induced in four other specimens of Clitoria. It is to 

 be remembered that N, N', and A, R, are at right angles to 

 each other. 



