ON LIVING MALAPTEKUKUS. 373 



soon. In the summer of 1859, Bence Jones sent two fish through 

 the captain of a ship by way of Liverpool. The ship, which 

 brought them from Hull to Hamburg, had such a stormy passage, 

 that on arrival here, one fish was dead, and the other apparently 

 dying, with white corneas and bent barbels. I succeeded in restoring 

 it, by exposing it for weeks to a stream of fresh water, and it was 

 just this fish which lived longest of all, till the autumn of 1864, and 

 it grew considerably in confinement. 



I kept the Malapterurus in a trough four feet (125 cm.) long, 

 one foot and a half (47 cm.) broad, and two feet (63 cm.) deep, the 

 floor of which was formed by a slab of slate, and its walls were of 

 plate glass. The trough was filled with tap-water up to 5 cm. 

 from the edge, which was renewed at a sufficient rate. In order to 

 maintain the temperature at the proper height, the trough stood in 

 a zinc case five feet (157 cm.) long, two feet (63 cm.) broad, and 

 thirteen inches (34 cm.) deep, encased in wood with a layer of 

 saw-dust, and its lid was fitted closely to the glass plates by means 

 of a packing of tow. The water in the zinc case was warmed by a 

 small copper boiler arranged at the side, the source of heat being 

 an Argand gas burner, so that a thermometer floating in the trough 

 indicated 17-5 2OC. Goodsir had told me that 70 Fah. = 2i-iC 

 is the proper temperature for the fish. But I found accidentally, 

 that they bore a temperature of only 15, and at one time, when I 

 fed the trough with spring-water, the Malapterurus which was 

 then the sole inhabitant of it, always sought out the very spot at 

 which water at only about 11 was flowing in. As the animal was 

 in a state of inanition, perhaps its instinct impelled it to diminish 

 its respiration and thereby its need of nourishment ; for Liebig's 

 assertion : * It is not a difficult task to endure hunger for a long 

 time at the Equator, but cold and hunger wear away the body in a 

 short time ' J does not hold good for animals of variable tem- 

 perature. 



Malapterurus take refuge in the dark whenever they can. I 

 covered the trough therefore with a wooden black varnished lid, 

 which shut out the light almost entirely, but admitted air. Water 

 plants in the trough and earth at the bottom of it make cleanliness 

 more difficult, without proving to be of any use. The trough must 



London by way of Hamburg, and Dr. Turner, at that time Goodsir's demonstrator 

 of Anatomy, had the goodness to bring the third with him by way of Leith and 

 Hamburg. 



1 Chemische Brief e, 3rd Edn. Heidelberg, 1851, p. 401. 



