92 COMPARATIVE ELECTRO-PHYSIOLOGY 



of one minute. An inspection of the record shows that 

 there is in such cases a complete recovery, at the end of 

 which the molecular condition is the same as before stimula- 

 tion. Hence, successive responses are exactly similar to each 

 other. The stimulation-rhythm was now changed, to intervals 



FIG. 57. Photographic Record of Uniform Responses (Radish) 



of half a minute instead of one, while the stimuli were main- 

 tained at the same intensity as before. It will be noticed 

 (fig. 59, fr) that these responses are now of much smaller 



FIG. 58. Photographic Record of Uniform Response in Petiole of Fern 



amplitude, in spite of the equality of stimulus. An inspec- 

 tion of the figure also shows that, when greater frequency of 

 stimulation was introduced, the tissue had not had time to 

 effect complete recovery from previous strain. The mole- 

 cular swing towards equilibrium had not yet abated, when 



