32 THE LIFE OF THE SALMON 



This is pretty good evidence that the first re- 

 appearance in fresh water of the fish which descended 

 to the sea as smolts about twenty-six months old is 

 not less than a year later when, as grilse, the fish 

 are three to three and a half years old. The 

 average weight of the Tay grilse mentioned is 

 5j lb., which gives an average increase, taking 

 fourteen months as the interval, of 6 oz. a month. 

 The increase in length may be taken as fully four- 

 fold. This rate of increase is surely more in harmony 

 with what we know of the growth of other creatures 

 having a duration of life similar to that of the 

 salmon than with the sensational increase demanded 

 by the view previously held, and stated as a proved 

 fact by several writers, that grilse come into our 

 rivers after an absence of only a month or two. 



Reference has been made to the food of the Black- 

 pool smolt. In a little book, now out of print, on 

 the natural history of the salmon, written by a 

 salmon curer and tacksman of fishings at Inverness, 

 named Alexander Fraser, and published in 1830 at 

 the Inverness Courier office, I find this shrewd 

 observation : "I have found seven small fish in a 

 grilse of 3j- lb., and several, particularly herrings, 

 in the body of salmon." The writer then goes on to 

 speak of the sea as the feeding place of the fish : 

 "Salmon in lakes and rivers can, like other fish, 

 subsist for some time on little or no food. In the 

 river Ness they have been known to continue for 

 about eighteen months, the interval between their 

 entry and their departure for the sea, and during 

 this time their food must be very limited indeed. 



