ON LIVING MALAPTERURUS. 377 



dark as to the precise course of events, if I had not taken the pre- 

 caution to place the electrodes of the frog-alarum in one of the 

 tubs. But this betrayed clearly enough what took place. Its bell 

 went on ringing continuously, indicating now a strong, now a weak 

 branch current in the nerve, either because the fish discharged with 

 different strength, or because the electrodes took up a more favourable 

 position at the moment of the discharge. The hammer seemed 

 sometimes to stick to the bell, indicating that the electrical fish was 

 tetanising its victim. Now followed an interval of peace, until 

 presumably, the tench, aroused from their stupefaction, began again 

 to move, and the Malapterurus also rested, felt disposed for a fresh 

 attack. Ever and anon the tumult started again, now in one 

 vessel, now in the other ; the individual periods, however, became 

 always shorter, and were separated by longer intervals. I then 

 left the field of battle. When I came into the laboratory the next 

 morning, the loaches lay dead upon the ground. Thus during the 

 night, they had again escaped even over the edge of the tubs 5 cm. 

 high. In the tubs of the two larger fish, the tench were dead. 

 They must have been dead a long time, because they were stiff and 

 their corneas had begun to cloud. The water was clear, thus peace 

 had long prevailed. The little adventure did not seem to have 

 affected the Malapterurus. The smallest had not been able to kill 

 its tench, but it died very shortly after, although I put it in 

 another vessel. A fourth couple of tench and loach, which I kept 

 as a check on the experiments in a fourth tub, under circumstances 

 quite the same in other respects, lived for weeks afterwards. 



A frog, under the effect of the discharge of the Malapterurus, 

 stretches itself as in tetanus from strychnine. But on account of 

 the poisonous skin secretion of the batrachians 1 , I did not make 

 any experiment with them, similar to the foregoing one. The fish 

 allowed earth-worms to curl themselves about their barbels without 

 discharging (comp. above, p. 374). But in general they seemed not 

 to give a shock when their barbels were touched, but to draw back ; 

 on the other hand, as already observed, when the skin was touched, 

 they discharged almost invariably. 



When the fish became ill, they changed their habits very much. 

 They forgot their fear of light, and without allowing themselves to 

 be frightened away by the proximity of an observer, they kept 

 themselves at the surface by a quick and laboured action of their 



1 Untersuchungen, etc., vol. ii. Abth. i. p. 17. Anm. 2. Comp. Gratiolet et Cloez, 

 Comptes rendus, etc., 1851 ; t. xxxii. p. 592. 



