Jennings, Reactions to Electricity. 533 



rent should be different in the two cases. The experimental portion 

 of the paper consists in a demonstration, by means of fitting apparatus 

 that this is actually' the case. 



This result shows only that there is nothing in the conditions to 

 make such movement as Birukoff assumes a priori impossible. It 

 of course by no means shows that electrotaxis actually takes place in 

 the way Birukoff supposes. Birukoff's theory for these conditions 

 is really completely disproved by the fact, set forth by Putter and 

 others, that after the Paramecia have been for a short time in the salt 

 water, so as to become accustomed to it, they no longer go to the 

 anode, but as usual to the cathode. Birukoff of course recognizes 

 that this if true is fatal to his view. He attempts to meet it by as- 

 suming that Putter's observations were due to preposterously crude 

 experimental errors, and that the facts are not really as Putter states. 

 But the facts have been established beyond doubt, not only by the 

 observations of PttTTER, but by the careful work of Statkewitsch 

 above set forth. The present writer can testify from his own observa- 

 tions to the accuracy of their accounts. 



It seems incredible that anyone should yet, after all the thorough 

 work that has been done on the movements of the cilia, hold that the 

 movement to cathode or anode is a passive one, due to the cataphoric 

 action of the current. This possibility is of course the first one to 

 occur to the observer, and it is the first one to be dismissed after the 

 facts are carefully observed. Before the current is passed through 

 them, the infusoria are moving about in all directions. Now the cur- 

 rent is closed, and all continue to move at approximately the same 

 rate as before, but they all now swim towards the cathode. There is 

 then not the faintest shred of evidence that the movement is due to 

 cataphoresis. The movement existed before the cataphoresis came 

 into effect ; the only essential difference between the later motion and 

 the first one (with one exception to be mentioned) is that the move- 

 ment is now directed toward the cathode. The observed movements 

 of the cilia, which are demonstrated by the currents produced to be 

 powerful, must cause the animals to move forward, just as when no 

 electric current was acting. There is no reason whatsoever for calling 

 in the cataphoric action to transport the animals ; there is nothing for 

 it to do. 



The one difference in the movement of the cilia is the fact that 

 some of the cathodic cilia show a reversed stroke. Neither Birukoff 

 nor anyone else has attempted to show how this can be a direct effect 

 -of cataphoric action. The observed movements of the cilia account 



