\0 COMPARATIVE ELECTRO-PHYSIOLOGY 



TABLE SHOWING THE INCREASED ELECTRO-MOTIVE VARIATION INDUCED 

 BY INCREASING STIMULUS. 



In such normal cases an increase of response is always 

 induced with increasing stimulation. A diminution of 

 response may, however, sometimes appear, with increasing 



FIG. 30. Increased Response with Increasing Vibrational Stimuli 

 (Cauliflower-stalk) 



Vertical line = *i volt. Stimuli applied at intervals of three minutes. 



stimulus. But this is merely a secondary effect, due to 

 fatigue. The following records (fig. 31) will show in what 

 manner this may be brought about. They were taken with 

 specimens of the petiole of cauliflower, in one of which (A) 

 fatigue was absent, while in the other (B) it was present. In 

 the first specimen the recovery from each stimulus was 



