RELATION OF BURSARIA TO FOOD 



27 



When, however, a direct current is used of such strength that 

 the organisms can be made to go to one side or the other by 

 reversal of the current the effect becomes more or less apparent. 

 Feeding can not be prolonged to twenty minutes with a strong 

 direct current, for the organisms are easily injured. To obviate 

 this, timie of feeding was limited to five minutes. The animals 

 were made to swim from one side to the other by frequent rever- 

 sals of the current. In Experiment X, they were stimulated by 

 frequent reversal of the direct current during the first minute 

 of feeding and then left to feed four minutes more without stim- 

 ulation. In Experiment XI they were stimulated in the same 

 way during the whole period of feeding. Time of feeding, five 

 minutes (tables 11 and 12). 



TABLE 11 

 Experiment X 

 Stimulated by direct current, 1 minute 



Control: No current 



7 6 4 6 3 810 7768504339 410 



118 



TABLE 12 



Experiment XI 

 Stimulated by direct current, 5 minutes 



As the results show, feeding was not discontinued under these 

 conditions of strong stimulation by the current, though the or- 



