30 COMPARATIVE ELECTRO-PHYSIOLOGY 



out, that for convenience of inspection, the records in this 

 book have been so taken that the normal electrical responses 

 of galvanometric negativity, unless specially stated to the 

 contrary, are seen as up-curves, galvanometric positivity being 

 represented by down-curves. These excitatory responses of 



FIG. 26. Photographic Record of Uniform Responses (Radish) 



galvanometric negativity are obtained with all plants, and 

 with every organ of the plant. I give here a table containing 

 a list of specimens which will be found on stimulation to give 

 fairly large electro-motive effects, occasionally as high as 

 i volt. 



