502 Journal of Comparative Neurology and Psychology. 



above, cannot then be accounted for as due to the weakening 

 of the current affecting them. Tliis is true a fortori of the 

 swimming backward of individuals that come in contact with a 

 surface, for such swimming backward occurs under other condi- 

 tions only in stronger, not in weaker, currents. There is no 

 escape from the conclusion that the contact reaction interferes 

 with and modifies in a striking manner the reaction to the elec- 

 tric current. 



Statkewitsch's view that the supposed interference be- 

 tween the effects of the two stimuli is to be explained in the 

 simple physical way he sets forth seems based largely on an a pri- 

 ori conviction that the electric current must always produce the 

 same reaction when it acts upon the same organism with the 

 same strength (see for example Statkewitsch, 1903, p. 46). 

 This conviction appears in a most curious way in his attempts 

 to demonstrate the correctness of his view. In his earlier pa- 

 per (1903, p. 47) he promises to demonstate in his final paper 

 that the supposed interference does not exist, but is to be ex- 

 plained by the division of the current, in the way above set 

 forth. In the final paper this promised demonstration takes 

 the following form: "For demonstration of this condition it is 

 not necessary to search out any methods of registration ; for 

 this purpose the very objects on which we are experimenting 

 can serve most excellently; a more sensitive galvanometer than 

 Paramecium, indeed, one need not demand. Its reactions to 

 the current present unchanging, definite phenomena, taking 

 place in accordance with law, dependent on the strength of the 

 acting current. The orientation with relation to the cathode, 

 the increase in the rapidity of progression up to a definite limit, 

 the changes in the form of the body — all these appear at a 

 definite intensity of the current, which demonstrates in an im- 

 mediate way that through the bit of detritus and the protist at- 

 tached to it passes a current of less intensity than in the neigh- 

 boring fluid, where the reactions of the infusoria are more pro- 

 nounced " (1903 a, p. 55, translation). Now, the question at 

 issue was whether the electric current of a given strength does 

 as a matter of fact always produce the same reaction on the 



