EFFECT OF ELECTRIC STIMULATION 321 



will be noticed that stimulation, thus applied at a distance, 

 was transmitted and induced an inhibitory effect in diminish- 

 ing the amplitude of normal pulsation. On the cessation 

 of excitation the pulsations are seen gradually to regain 

 their normal amplitude. This inhibitory effect is what 

 takes place more frequently, and may be regarded as typical. 

 Somewhat exceptional is the converse effect of augmentation, 

 seen in the next record (fig. 165). The particular specimen 

 was less vigorous ; this fact is seen in the smaller amplitude 

 of its normal pulsations, the magnification being the same 

 in the two cases. After these normal pulses had been 



Fig. 165. — Augmented pulsation induced by transmitted 

 excitation in less vigorous specimen of Desmodium. 



recorded, indirect stimulation of moderate intensity was 

 applied, as in the previous case. It will be noticed that, in 

 consequence of this, there occurred a marked enhancement 

 of the amplitude of pulsation. Even on considerably 

 raising the intensity of the stimulation this enhancement of 

 pulsation still persisted. 



A remarkable parallelism has thus been shown to exist 

 between the responsive characteristics of rhythmic animal 

 and vegetal tissues. This is seen in their incapability of 

 tetanus, in their prolonged refractory period, in the extra 

 pulsation induced by electric shock at the diastolic phase, 

 and in the transmitted excitation causing in different 

 circumstances effects either of inhibition or acceleration. 

 Other similarities, equally remarkable, will be found in the 



