PRACTICAL CARP CULTURE. 80 



our ears are stopped, and when the vibrations must pass through the 

 bones of the head in order to reach the inner ear. But the ear of the fish 

 is organically stopped and consequently has no opportunity of receiving 

 such air-vibrations. But those of the heavier liquid, the water in which 

 it lives are quite capable of penetrating the skull. There cannot be a 

 shadow of doubt that fish can hear sounds under water, that is, can feel 

 vibrations conducted through the water. Stamp on the ground by the 

 side of a fish-pond and you may see them start. Explode a cracker under 

 water and note the commotion that follows. But on the other hand many 

 kinds of fish seem indifferent to the voices of persons talking near them 

 though anglers usually maintain perfect silence "lest the fish should 

 hear them." Many a time was I told when a boy by some patient sports- 

 man to " keep quiet and not frighten the fish." Probably all fish are not 

 equally sensitive in this respect. But it is also quite likely that the noise 

 of an ordinary conversation is not loud enough to create a vibration in the 

 water sufficiently strong to disturb them. 



A w r riter in the November number of the " Journal of Carp Culture," 

 (1887) after telling how he made a clock to deliver food to the carp in his 

 pond says that on its striking a 30-pound bell once a day the fish assem- 

 bled in great numbers at the feeding place. Here the loud sound is con- 

 ducted down the sides of the building "which stands in the pond" and 

 spread through the water. It is consequently a water wave and not the 

 air-wave that the fish perceive. In this way we may I think account for 

 the rather contradictory opinions that have been published regarding the 

 hearing of fish. 



The above is a general account of the structure of the ear among fishes, 

 but it cannot be literally and exactly applied to every fish. In so large a 

 class covering as it does so great a range of structure many differences 

 must be expected. So we -find it. The widest divergence from the type 

 is in the semicircular canals. These are not equally developed in all fishes. 

 Among our common fresh water species we find much variation in this 

 respect. In the herring of Lake Erie, for example, the exterior and pos- 

 terior canals are present and are embedded in bony tubes in the walls of 

 the skull the former in the parietal and the latter in the occipital bone. 

 The anterior canal is also present but scarcely sunk in the bone at ail, its 

 tube being very short and for the most part cartilaginous. In the pickerel 

 again the posterior and exterior canals are embedded in the bone but the 

 anterior is only sunk in a groove formed by a projecting plate arising from 

 the base of the chamber. 



Numerous other departures from the typical ear of the fish could be 

 cited to show how this organ can be traced from stage to stage in degree 

 of complexity downward until it becomes almost rudimentary. But to 

 do this would not come fairly within the proper domain of this chapter, 

 and it must suffice to say that in the sea-lampreys we find an ear whose 

 simplicity is almost as marvellous as is the complexity of the ear in man. 

 In these lowly fish the ear-bones are not fotuid at all, and consequently the 

 membranous sac which Usually contains them is absent. Further the 



