70 CHAP. VII. EFFECT OF ELECTRIC STIMULATION 



The latent period in the responsive variation of growth is 

 shortened under stronger stimulus, but the period of recovery 

 becomes protracted. 



Under increasing intensity of stimulation the con- 

 tractile reaction becomes more and more pronounced. At 

 a critical intensity of stimulus, growth becomes arrested ; 

 under a still stronger intensity there is an actual shortening 

 of the organ. Continuity thus exists between incipient and 

 actual contraction. 



The distinction between the responses of pulvinated and 

 growing organs is arbitrary. Growing organs are capable 

 of repeated response, just as are pulvinated organs. 



