FUNCTION IN PLANT LIFE 35 



examined there was clear evidence of the previous existence 

 of the conducting layer, c, and the three membranes were 

 present, i.e., the outer shell, a fibroid lining within that, 

 and a third enclosing what I have termed the seed sub- 

 stance. In lieu of the tongue-like protuberance with 

 which the chestnuts are provided a sharp point projecting 

 inwardly from the base of the nut seemed to have served 

 the same purpose, and at the apex was another point 

 evidently open at one time to the air. In regard to 

 colouring there was again in the white of the nut a faint 

 tinge of lemon-yellow. I exposed one half to bright and 

 the other to diffused light for four hours, when that in 

 diffused light was apparently unchanged, while the other 

 had taken on a tint of slightly deeper yellow. 



THE ELECTRODES AND ELECTROLYSIS. 



Where contacts of prolonged duration are made, as 

 in the foregoing tests for capacity, suspicion naturally 

 attaches to the electrodes, and it might be thought 

 that the changes of polarity observed were due to 

 polarisation. In this connection I would point out two 

 things, i.e. (I) the needles were in some instances 

 cleaned and reinserted without polarity being affected, 

 and that in the orange test there were merely signs 

 of electrolysis, and (2) that supposing 1-5 volts had in 

 ten minutes polarised the electrodes inserted in the 

 fruit or vegetable to such an extent that polarity was 

 reversed for twenty minutes, it is difficult to see how an 

 electromotive force of about 0-086 volt (i.e., that of the 

 vegetable cell) could restore the original polarity in another 

 twenty minutes while the electrodes remained in position. 

 Moreover, I have by repeated experiments, extending over 

 a course of years, established the fact that it is impossible 

 to alter the polarity of a vegetable cell by subjecting the 



