THE MANIFESTATIONS OF LIFE 



61 



Tradescantia, show a disturbance by which the delicate 

 protoplasm is collected into nodular masses. 



When amoeba and leucocytes are subjected to the 

 irritation of galvanic currents passed through the fluid 

 in which they are suspended, they draw in their pseudo- 

 pods, cease amoeboid movement, and may even suspend 

 the cytoplasmic circulation. If the current be of mild 

 intensity, its effect soon wears off and activities begin 



Fio. 13. Result of electric stimulation of plant protoplasm as shown in the 

 cells of the hairs upon Tradescantia leaves. A, Quietly streaming cytoplasm; 

 B, changes produced by the passage of an electric current, the cytoplasm be- 

 ing gathered into small globular masses at c and d. (After Kuhne.) 



again. If, however, its intensity be greater, disintegra- 

 tion of the protoplasm follows. 



When water containing paramcecia is subjected to a 

 constant current of mild intensity passed from one side 

 to the other, the organisms abandon the positive (anode) 

 pole and collect at the negative (kathode) pole. 

 . When a single organism subjected to a galvanic 

 current is examined microscopically it is found that 



