228 RESEARCHES ON IRRITABILITY OF PLANTS 



excitation took place at kathode at make and at anode at 

 break. The experiment was repeated with ten different 

 specimens, the result being always the same. 



The excitatory reaction in this plant is thus charac- 

 teristically the same as in others already described. 



Leaflets of Averrhoa bilimbi 



The excitability of these leaflets is perhaps slightly 

 greater than that of A. carambola. I carried out the usual 

 cycle of observations on the effects of feeble and moderate 

 currents, employing in each case five different specimens. 

 The two bi-polar contacts were made in the case of the 

 same leaf 7 cm. apart. 



Effect of feeble current. — The excitatory effect of kathode- 

 make characteristic of Type I. was exhibited with an e.m.f. of 

 10 volts, the current being 6 micro-amperes. The electrical 

 resistance offered by the petiole of this plant was much 

 less than that of A. carambola. All the specimens, without 

 exception, gave the effects characteristic of Type I. under 

 feeble current. 



Table X. — Effect of Feeble Current on Leaflets of 



Averrhoa bilimbi 



e.m.f. = 10 volts ; current = 6 micro-amperes 



Effect of moderate current. — When the e.m.f. was raised to 

 28 volts, with a resulting current of 16 micro-amperes, the 

 effects induced were characteristic of Type II. That is 

 to say, excitation was shown at the kathode at make and 



