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 

 59 ^) tnat 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 



