104 RELATION OF PLANTS TO ELECTRICITY 



160. Effect of Electric Current on Streaming Movement of 

 Protoplasm. Secure a leaf of Philotria or a stamen hair of ' 

 Tradescantia exhibiting movement, and mount it on a slide with 

 binding post and clips (See Fig. 46). Place the material so that 



a minimum amount of water 

 will cover it and the cur- 

 rent will traverse the section 

 lengthwise. Connect a sin- 



FlG. 46. Slide fitted with binding posts and gl e ammonia cell of the Le- 

 clips for sending currents through an object i -i c . ■. i 



. a a 1 f& * 1 lanche or Sampson type with 



mounted under a cover-glass. After Arthur. m r J r 



the lower binding posts of 

 a DuBois Raymond inductorium with a key in the circuit. 

 Connect the upper binding posts with the fittings on the slide. 

 With a moving strand under observation close the key. This 

 will cause a primary alternating current to pass through the ma- 

 terial. Note results. 



Using the same or a new mount connect the slide with the 

 binding posts of the secondary coil, which should be moved to a 



Fig. 46. DuBois-Raymond inductorium. After Verworn. 



distance of 35 cm. from the primary coil on its sliding base. 

 Close the circuit with the key for five seconds. Move the secon- 

 dary coil successively up to 30, 25, 20, 18, 16, 15 and 14 cm., 

 and note results. After the material has been disorganized by the 

 strongest stimulus describe the condition of the cell. 



