ON LIVING MALAPTERURUS. 



Small resistance. 



403 



Great resistance. 



If shocks were taken from the fish alternately with covers with 

 long and short linings, the greater strength of the latter was very 

 clear. 



10. More precise examination of the value of the Frog- 

 interrupter in experiments on the Malapterurus. 



I do not return here to a detailed consideration of the questions 

 as to the time relations of the shock, but refer to what has already 

 been said on this matter in discussing the frog-interrupter, p. 385. 



In the ' Description of certain Apparatus and Methods of Experi- 

 ment,' it was shown that the frog-interrupter serves the purpose of 

 opening the circuit at any required short period after the excitation 

 with sufficient accuracy. Consequently the great irregularities 

 which were always observable in the effects of the shock of the fish 

 were the more obvious. They finally led me to decide on testing 

 the action of the interrupter in experiments on the fishes them- 

 selves also, although it seemed inconceivable that it should not do 

 here what was expected from it. 



At first, I simply made series of experiments with increasing 

 overweight, in order to see how the deflections caused by the fish 

 shock would increase correspondingly to the overweight. Thus I 

 obtained (with 53 turns at 75 mm. distance) the series immediately 

 following, in which W.I. signifies ' without interrupter:' 



The fall of the deflections at the close of the second series may 

 be explained thus : at the time of the interruption, a great part of 



D d 2, 



