i8 93 . NOTES AND COMMENTS. 245 



them in the process. Some further experiments on the subject have 

 been made by Mr. Gregg Wilson in the Plymouth Marine Biological 

 Association, and the following observations from his recent report to 

 the British Association will be read with especial interest : — 



"So far as I could determine, fish that are not very hungry 

 habitually smell food before taking it. The pollack seems usually to 

 be ready for a meal, and on almost all occasions when anything 

 eatable is thrown into the tank in which it is swimming, it rushes 

 towards it and bolts it. It does not hesitate to take stale food or 

 food that has been steeped in strong smelling fluids ; and time 

 after time I have been amused to see its too-late repentance, 

 after it had swallowed clams that had been saturated with 

 alcohol, chloroform, turpentine, etc. It is only when it is satiated 

 with fresh food or disgusted with what is nauseous that it takes the 

 precaution to smell before eating. On the other hand, various fish 

 that are equally keen-sighted, and habitually recognise their food by 

 the use of their eyes, are more prudent. The whiting (Gadus mer- 

 laiigus), for instance, appears to pay much more attention to smell, 

 and, as a rule, turns about and withdraws on approaching within a 

 few inches of high-smelling objects that the pollack would take 

 without hesitation. Even whiting, however, cease to be delicate if 

 they are very hungry, and if other fish are present to compete for the 

 food that is thrown to them. In such circumstances bait that is very 

 distasteful may be taken by even the most cautious of sight-feeders ; 

 and likewise, in such circumstances, a quite smell-less artificial bait 

 may be successfully employed. Where large shoals of fish are, there 

 are likely to be many that are very hungry, and the consequent keen 

 competition will lead to hasty feeding by sight alone ; and hence it is, 

 probably, that lead-baits are successfully employed in cod fishing in 

 the Moray Firth and off the Northern 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 smelling it ; and Bateson quite recognised this. 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 

 deciding that it was by smell alone that they found their food. Their 

 conduct was exactly such as was seen in the smell-feeders, to which I 

 shall presently refer. 



" Again, the cod {Gadus morrhua), which Bateson puts among the 

 sight-feeders, is generally believed — and with good reason, I think — 

 to feed more by night than by day ; which suggests that it, too, not 

 only tests its food, but actually hunts by smell. 



