loo THE HABITS OF THE SALMON. 



warmer temperature too soon, as they dislike the 

 sudden change, and swim backwards and forwards 

 in the tideway for a time before they face pure 

 salt water. The case is different with adult spent 

 fish, for they do not tarry in the tideway, but go 

 straight out to sea without fear or delay. Again, 

 in "Salmon Problems" Mr. Willis Bund gives 

 an interesting account of some smolts beiiig trans- 

 ferred from fresh to undiluted salt water which 

 was in the Brighton Aquarium, and the writer 

 states that each fish when dropped into salt water 

 gave three little sobs, just as though the dose 

 was rather too strong. They afterwards coursed 

 rapidly round the tank, and then settled down into 

 their ordinary mood. Surely this experiment may 

 induce us to assume that smolts object to any 

 sudden change of temperature, and therefore it would 

 not be at all surprising if grilse, in their immature 

 stage, also object to such a sudden change. This 

 may be why they prefer to stay in the sea during the 

 cold wintry weather. It is true that grilse oc- 



