28 COMPARATIVE ELECTRO-PHYSIOLOGY 



galvanometric negativity, all these effects being concomitant. 

 It was further shown that electrical response is independent 

 of the mechanical, being unimpeded in its occurrence when 

 the leaf is physically restrained. 



The same electrical response of galvanometric negativity 

 is also obtained from the tissues of the so called ' ordinary ' 

 plants. And these electrical responses of plant tissues, it was 

 further noted, are identical in sign with the corresponding 

 responses given by animal tissues. 



All forms of stimulus, moreover mechanical, thermal, 

 photic, chemical, and electrical induce the same excitatory 

 response of galvanometric negativity. 



