A. R. SCHRANK 



127 



(27). Similar electrical changes have also been observed by other workers 

 for stems of other plants (2,4,5). However, Brauner and others reported 

 comparable results from plants that had been killed in boiling water and 

 from models constructed out of nonliving membranes (6,7,8). Because 

 of the results obtained from the models these workers were led to 

 maintain that the electrical responses were nonliving phenomena, and 

 Brauner and Amlong ascribed the geoelectrical changes to streaming 

 potentials (7). The data shown in Figure 2 were obtained from non- 



Millivolts 



+ 10 - 



Figure 2. A. Transverse electrical changes in Avena coleoptiles that are 

 rotated from vertical to horizontal position. Contacts 2 millimeters below 

 apex. Average of 6 experiments. B. Upward curvature of coleoptiles in hori- 

 zontal position measured in ocular scale divisions of 18 per millimeter. Average 

 of 10 experiments. 



