504 Journal of Comparative Neurology and Psychology. 



current tliat deserve mention. First, one often observes that 

 wh.ile most of the specimens in a preparation are reacting pre- 

 cisely and strongly, a few specimens do not react at all, swim- 

 mmg about at random. Second, one at times observes single 

 specimens that swim toward the anode, while all the others go 

 toward the cathode. This is most likely to be observed after 

 the current has been reversed several times, though it is some- 

 times seen at the beginning of the experiment. After repeated 

 reversal of the current, one sometimes makes the following ob- 

 servation. A specimen is oriented and swimming toward the 

 cathode ; on reversal of the current it retains its orienta- 

 tion and continues to swim forward — now of course toward the 

 anode. A third very peculiar irregularity that is less unusual 

 than the others is the following. In a ratner strong current the 

 animals are swimming slowly and in a rather cramped way to- 

 ward the cathode. Now the current is reversed, whereupon, 

 without rurning around, they swim rapidly backward to the 

 cathode. By repeatedly reversing the current, the animals may 

 sometimes be caused to alternate several times, first swimming 

 forward, then backward, retaining throughout the same posi- 

 tion. But usually after swimming backward a short time to- 

 ward the cathode, the animal turns around and swims to the 

 cathode in the usual way. All these irregularities are so com- 

 paratively unusual that I have not been able to determine pre- 

 cisely the nature of the ciliary movements. 



Reaction of Paranuxia to Electricity zv/ie/i in Solutions of 

 Chemicals. — Greeley (1903) has recently raised anew the ques- 

 tion as to the significance of certain peculiarities of the reaction 

 to the electric current when the animals are in solutions of cer- 

 tain chemicals. He points out that in acid solutions Paramecia 

 move to the anode, whereas, under usual conditions, where the 

 solution is alkaline or neutral, they move to the cathode. This 

 he attempts to bring into relation with the observations ol Lil- 

 LiE (1903), who shows that cell constituents containing much 

 nucleic acid migrate to the anode as an effect of electrical con- 

 vection, and that the tendency to migrate to the anode decreases, 

 with the decrease in acidity. In this way we seem to be on, 



