82 THE STORY OF FISH LIFE. 



islands, while they are of no avail among the 

 scanty fish further south. 



" It may be said that in these cases the fish 

 actually search for their food by sight alone, and 

 merely test the quality of what they have found 

 by soaelling it. . . . But more is possible : habitual 

 sight-feeders can be induced to hunt by smell alone. 

 The pollack, which is such a pronounced sight- 

 feeder that it will take a hook baited with a 

 white feather or a little bit of flannel, and trolled 

 along the surface, is yet able, when blinded, to 

 get his food with great ease. Several blind 

 specimens in the Plymouth tanks were carefully 

 watched by me, and I had no difficulty in decid- 

 ing that it was by smell alone that they found 

 their food. Their conduct was exactly such as 

 was seen in the smell-feeders. . . ." 



The cod-fish is generally believed to feed more 

 by night than by day, hence we may conclude it 

 is a "smell-feeder." 



Mr G-regg Wilson has also placed on record 

 the results on some of his experiments with 

 certain other fish, which throws yet more light 

 on this subject. Thus with the dabs (Pleuronectes 

 limanda). "That they were sight-feeders," he 

 says, "was evidenced by their behaviour when 

 I lowered a closed tube full of water, and with a 

 worm in the middle of it, into their tank ; time 

 after time they bumped their noses against the 

 glass at the very spot where the worm was 

 situated. That they could also recognise the 

 smell of food, apart from seeing it, was demon- 

 strated in various ways. First, if instead of a 

 closed tube . . . one open at the bottom was 



