INFLUENCE OF CURRENTS OF ELECTRICITY 



105 



161. Influence of Induced Current upon Mimosa. Place a num- 

 ber of young plants of Mimosa in a warm room with high hu- 

 midity. Connect the DuBois-Raymond inductorium with the 

 batteries, leaving the key open. Push the secondary coil up 

 over the primary coil and con- 

 nect the binding posts with 



the non-polarizable electrodes. 

 Support the electrodes so that 

 one will be in good contact with 

 base of stem and the other with 

 apex. Close circuit for a mo- 

 ment and note result. If no 

 reaction is exhibited, replace 

 electrodes with needles, and 

 after plant has recovered from 

 shock given by thrusting them 

 into the tissues, close circuit 

 again and note result. The 

 outer membrane may prove too 

 highly resistant to secure reac- 

 tion from the non-polarizable 

 electrodes. 



162. Influence of Currents of 

 Electricity Upon Growth : Direct 

 Current. Place 500 or more 

 seeds of mustard, radish, or 

 turnip which possess a ger- 

 minating capacity of at least 85 

 to 90 per cent, in water for a 



period of twelve hours. Take one cc. or more of the seeds and 

 put them into a glass tube of about three-eighth inch diameter 

 (a graduated piece of discarded burette tube will answer best). 

 Solder two copper disks about the size of the inner diameter 

 of the tube to two wires. These will serve as electrodes. Now 

 insert the electrodes into the glass tube bringing them into direct 



FIG. 48. A, stamen hair of Trades- 

 cantia Virginica with moving strands of 

 cytoplasm. B, same after action of in- 

 duced current, a, b, c, d, irregular masses 

 of cytoplasmic material. After Kiihne. 



