106 The Salmon 



since descending the previous February, having spent eighteen months 

 in the sea before again returning to fresh water. Before descending 

 the scale shows a hundred lines, in addition to forty-two parr lines, 

 quite the greatest number on any scale that I have examined from 

 Tay salmon. I make this fish to have descended when three years 

 old. 



SALMON SCALES FROM NORWEGIAN FISH 



It might be of interest to compare a few scales from fish of 

 Norwegian rivers with those taken from our Tay fish. Col. Percy 

 Hargreaves very kindly sent me some scales to examine (withholding 

 name of river, date, and weight) from fish caught by him during 

 season 1910. On examination I had little difficulty in detecting the 

 time each had entered the river, its age, weight, and average weight 

 of the whole, which I put down at 27 Ibs. This proved to be within 

 3 oz. of the actual weight. Col. Percy Hargreaves' description of 

 the river is as follows :- -The Aaro in the Sognfield, near Sogndal, 

 about seventy miles N.E. of Bergen, rises in a lake called the Hafsh 

 Lake, and is about seven miles long. Salmon can only ascend for one 

 mile, the other six miles being a series of waterfalls. The river for 

 about six miles is nearly fifty yards wide, and is more like a mill-race 

 than anything else. The lake is fed from a very large glacier, and 

 from December to April the fishable part of the river is almost dry. 

 As far as I can gather, nearly all the fish and burn-trout leave the 

 river by December ; a few may remain, but very few. 



From a close examination of these Norwegian scales I have 

 come to the conclusion that nearly all the parr become smolts when 

 under two years of age. Most of the scales have on an average 

 twenty-five lines on them before any change takes place, and on the 

 larger fish this is clearly seen. On the other hand, all the smolt 

 scales I have examined show more lines than are to be seen on those 

 of the large fish. If I were to judge from the scales of the large fish 

 when the smolts went down, I would say at twenty-one months, but 

 judging from the smolt scales, I should say twenty-six months. No 



