THE SCALES OF THE SALMON ID^ 275 



eighteen fresh rings to be counted. As no one, however, 

 can possibly tell how many rings were lost during the first 

 decrepitation, the exact age of the salmon is indeterminate. 



Mr. Hutton notes on this photo that the decrepitation at 

 "kelt " marks the fifth and sixth years of this salmon's life, 

 and, appreciating his exhaustive examination of this subject, 

 I should be inclined to believe in his estimate, but the scale 

 markings cannot be said to prove this. 



The decrepitations have effaced two thirds of all the 

 annular rings of the scale beyond the fourth year's markings, 

 and if the remaining third portion of these rings had been 

 also obliterated, there would have been no indication beyond 

 the size and weight of the fish to indicate the fifth and sixth 

 year of the salmon's life, and the scale would have appeared 

 somewhat as the scale shown in Plate XXVIIIb. 



If this scale is examined it appears to have belonged 

 to a fish which has had its scales decrepitated by previous 

 spawning conditions in its fourth year, and that it is again 

 running up in an attempt to reach the spawning grounds ; 

 but from its weight and the appearance of the scales it may 

 well be a five-year-old fish, i.e., a fish which has spent three 

 years in the sea, whose fifth year's annular markings have 

 been entirely lost through decrepitation, just as the others 

 have been over two-thirds of their extent on Plate XXXI. 



From this scale, and from many others I have examined, it 

 appears to me that at any time after the outside edge of the rings 

 of a virgin fish have been destroyed, a considerable uncertain! y 

 must exist in correctly determiningthe later history of ^the fish. 



THE SCALES OF SALMON FROM THE RIVER ADD 

 A paper recently published (1913) by the Fishery Board 

 for Scotland, entitled " The Scales of Salmon of the River 

 Add," by Mr. W. J. M. Menzies, has been referred to by 

 several writers as an " extremely interesting paper." 



