LIVING TOKPEDOS IN BERLIN. 419 



if they arrive in good condition and are kept quiet, they continue 

 healthy for six weeks without material loss of vigour. Subsequent!) 

 some animals died, which from want of leisure I had not been able 

 to use for experiment, but others survived several months, although 

 the temperature of the sea water was only 12 C 1 . According to 

 the statement of the keeper, the Torpedos as long as they are in 

 good health burrow in the gravel at the bottom of the tank and are 

 then difficult to distinguish from the ground 2 . They do not trouble 

 themselves about other fish in the tank. They were not seen to eat 

 any of the fragments of fish which were thrown into it as food. In 

 the free state Torpedos swallow, as Professor Fritsch ascertained by 

 examining the contents of the stomach, very large fish which they 

 previously paralyse by electrical shocks 3 . It is obviously, however, 

 not easy to provide living small sea fish for them in captivity. 



On the days of experiment the fish was transferred by means of a 

 landing-net into a tub of such size that two men could carry it 

 easily. And by the same means they were introduced into the ex- 

 perimental trough described below. The catching of the animal was 

 accompanied by violent struggles, in which, no doubt, the fish gave 

 repeated shocks, as was ascertained to be the case in the Gymnotus by 

 connecting it with a rheoscopic limb of the frog 4 . I tried to obtain 

 the same evidence here, but the rheoscopic limb remained motion- 

 less, no doubt in consequence of short circuiting by the sea water. 



After the fish had been introduced into the experimental trough 

 it remained quite quiet, the only motion visible being that of the 

 spiracles. If it was put back into the trough after a long series of 

 experiments, it swam wildly round and round, sometimes endeavour- 

 ing by peculiar undulating movements of its body to get over the 

 wall of the trough. 



1 Compare my observations as to the temperature at which pcekilothermal animals 

 should be kept. Gesammelte Abhandlungen, vol. ii. pp. 605, 606, and in the Unter- 

 suchungen, p. 77. 



2 It was stated by Reaumur and Walsh that Torpedos at low tide burrow in the 

 sand by working their pectoral fins, and that fishermen who step upon them with 

 naked feet fall down (Untersuchungen, p. 132). Here a Torpedo incident told me 

 by Ehrenberg may be mentioned, which gives an idea of the power of the Torpedos 

 in the Red Sea (probably T. panthera). Ehrenberg had waded with his Arab 

 servant on a coral reef deep into the water. Suddenly the man cried that a shark 

 had bitten his foot off, staggered, and was on the point of falling down. With the 

 quick perception of the naturalist, Ehrenberg reassured him with the words : * Do 

 not be afraid, there is no blood, you still have your foot, you have only trodden on 

 a "Raad."' 



8 Sitzungsberichte, 1883, v l- i. P- 2 o5- 

 4 Gesammelte Abhandlungen, pp. 615-617. 



E e 2 



