62 The Salmon 



The last number would make a salmon seven years old on its hrst 

 return from the sea. 



The Scales of Salmon 



For the last five years I have made a study of the scales ot the 

 salmon in all its stasfes, of the sea-trout and of the brown trout. The 

 late Lord Blythswood was the first to direct my attention to the im- 

 portance of the study of scales. This he did by describing the marks 

 on the scales, the result of feeding in the sea during summer and 

 winter. For a considerable time I made little headway, until I 

 found out from the parr and the smolt the number of lines added 

 to their scales in a year. This supplied me with a key to Lord 

 Blythswood's explanation, so that after collecting scales trom all the 

 different runs of fish, and at all seasons of the year for several years, 

 I was able to tell to within a month how long a fish had been in 

 the sea, and, of course, when it went down as a kelt, and whether 

 it was a grilse, small spring fish, autumn fish, or large spring fish. 

 I could also tell its age and its weight, and whether it had spawned 

 once or twice. This being so, I consider a stud)' of the scales the 

 most important means of determining the lite-histor)' ot the salmon 

 and the sea-trout. 



The study of scales is a very wide subject, but I shall endeavour 

 to condense m\- remarks as much as possible. Just as the age of a 

 tree may be determined by counting the number of rings on a cross- 

 section ot the trunk, where each ring shows the growth ot one year, 

 so the age ot the parr may be arrived at by counting the rings or 

 lines on its scales. The parr in a natural state, however, adds to 

 its scale each year not one ring only but sixteen, and this goes 

 on throughout all the life -history of the salmon as long as it 

 continues to feed and grow. In the parr fewer rings are put on 

 during the winter months than during: the summer months, but if we 



o o 



take a whole year the number works out as I have said, with very 

 few exceptions. I choose a year to calculate from, because it a fish 



