Table 3. --Electrotactic response of aholehole of various size 

 groups to increasing current at a constant "on- 

 fraction" of 0.08 and a frequency of 10 c.p.s. 



tests 5 and 6, there was much less confusion 

 and the school as a whole swann rapidly towards 

 the positive electrode. 



Discussion 



In the foregoing experiments only the total 

 peak current, I, was nneasured and recorded. 

 This quantity was also used in the tables and 

 graphs. The current density is, of course, the 

 more significant factor and it is related to the 

 total current by J = 1/A, where J i s the peak 

 current density and A is the cross-sectional 



area of the colunnn of water between the 

 electrodes. In table 5 the current densities 

 corresponding to the currents used in the 

 experiments are listed. 



The resistance between the electrodes was 

 found by measuring the voltage between the 

 electrodes for a given current. Then R = V/1, 

 where R is the resistance in ohms, V the voltage 

 in volts, and I the current in amperes. The 

 resistivity of the sea water can then be found by 

 the standard fornnula p = RA/L, where p is the 

 resistivity, R the resistance, A the cross-section 



Table 4. --Response of aholehole to the predicted optimum current. 

 Pulse frequency: 10 c.p.s.; on-fraction: 0.06 



