22 THE COMMERCIAL SEA FISHES OF 



and membrane, as well as a cochlea, are absent. Now it is 

 hardly to be supposed that this intricate auditory appa- 

 ratus exists without a purpose. As vibrations in the atmo- 

 sphere occasion sound, so likewise do they in the water, their 

 force being communicated to the sides of the body of the 

 fish, and on to the internal ear, either assisted or not by 

 the air-bladder. Lacepede relates how some fish which 

 had been kept in trie basin of the Tuileries for upwards of 

 a century would come when they were called by their 

 names ; while in many parts of Germany, trout, carp, and 

 tench were summoned to their food by the ringing of a 

 bell. Ellis, in his ' Polynesian Researches/ speaks of a 

 native chief of the island of Hawaii, who had brought eels 

 to that degree of tameness that he was able to call them 

 from their retreat with the shrill sound of a whistle. At 

 many temples in India fishes are summoned to receive 

 food by ringing bells or musical sounds. Carew, in Corn- 

 wall, called his grey mullet together by making a noise 

 like chopping with a cleaver, and Sir Joseph Banks col- 

 lected his fish by means of sounding a bell. 



The respiration of fishes is essentially the same as in the 

 higher vertebrata ; the blood is decarbonised at the gills by 

 absorbing the oxygen contained in the air which is in solu- 

 tion in the water. It may be carried on in more than one 

 manner in a fish at the same time ; thus in some tropical 

 countries this function in certain amphibious forms is more 

 completely effected by means of taking in atmospheric air 

 direct, the gills being insufficient to depurate the blood, 

 which is consequently affected by accessory breathing 

 organs (as in the climbing perch, the snake-headed or the 

 scorpion-fishes of India) ; while M. Jobert has ascertained 

 that in the Callichthys this accessory respiratory action is 

 performed by air passing through the intestines. And all 



