234 CAN FISHES HEAR? 



the shape of liberal handfuls of limpets and mussels. 

 Formerly, a wooden clapper used to be sounded to 

 summon them, but that was merely ceremonial; the 

 sound of a foot upon the stairs is quite enough. Some 

 may suspect that the fish see any one coming downstairs ; 

 but there is a singular circumstance which renders that 

 improbable. The only fish which it has been found 

 possible to keep in this pond are cod and coal-fish, which 

 devour every other species that may be introduced. It 

 invariably happens that the cod, accustomed to the green 

 twilight of the deep sea, suffer from excess of light in their 

 prison, and become blind if kept there long enough. You 

 may notice that their eyes exhibit every stage of opacity, 

 indicating all stages from mere dimness of vision to total 

 blindness. The coal-fish, I fancy, do not suffer in the 

 same way, being inhabitants of shallower water. Despite 

 their blindness, the cod manage to take very good shots 

 at the food provided, possibly being assisted by the sense 

 of smell. Many of them feed freely out of the attendant's 

 hands, or yours, for that matter, if you care to risk your 

 fingers being sharply nipped. Many years ago, when I 

 first knew the Logan fish-pond, the guardian of the fishes 

 was an old woman, who always had one particular pet in 

 the flock, an enormous cod, stone blind. Protected by a 

 canvas apron, she used to lift this fish bodily into her 

 lap, fill its maw with limpets, and launch it into the water 

 again. 



Those who are investigating the acoustic power of fishes 

 ought not to neglect a visit to this unique fish-pond, which 

 lends itself admirably to practical experiment. 



