82 THE HABITS OF THE SALMON. 



rivers, often return to sea and try to find the way 

 into their relative waters. 



The reason why salmon differ so much in shape 

 and condition may be this. As regards shape ; it 

 is probable that from the time they were hatched 

 out to the time they went to sea as smolts, they 

 were sustained by food of a more fattening nature 

 in some rivers and tributaries of rivers than 

 in others, and for this reason have developed into 

 larger and better-shaped fish as adults than those 

 which have had poorer food to live on. As regards 

 condition ; it is not unreasonable to assume that 

 salmon of every river have their own particular 

 feeding ground in the sea, to which they are 

 instinctively guided on leaving the fresh water, as 

 surely as they are to their native river, when they 

 return there as clean fish. Of course their condition 

 varies according to the quality of the food they get 

 in those feeding-grounds. Fresh-water fish differ in 

 size, shape, and condition in varices rivers, and this 

 can be accounted for only by the fact that the food 



