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THE ROYAL SOCIETY OF CANADA 



By this method the calculation can be made as accurate as it is 

 possible to divide the scale radius, and it should be possible to use it 

 with at least as great dispatch as Lea's method. As the same line, not 

 the same portion of it, may be used for several scales in succession, 

 the amount of preparation is practically nil. 



Little attention has been paid to the number of rings in any year's 

 growth as it has been observed in these species of salmon, as Miss 

 Esdaile, Dahl and others have shown to be true in the Atlantic sal- 

 mon and others have shown for other species, that the number of 

 rings in any year's growth may vary greatly, even in different scales 

 of the same fish, so much so that one scale may have more than twice 

 as many rings as another from the same fish, in the same year's 

 growth. 



Occasionally expression is still given to a doubt that the Pacific 

 salmon of the genus Oncorhynchus die soon after the first spawning, 

 although no direct evidence, with the exception of the appearance of 

 an alleged spawning-mark in some instances, that any of them ever 

 spawn a second time. Milne claims to have found a spawning mark 

 in a spring salmon scaled Yet in his paper he gives (fig. 107) a figure 

 of a sockeye scale, concerning which he says (p. 593): "its interest is 

 in showing, from the worn condition of its edge, that if a sockeye ever 



1 Milne, J. A., History of the Pacific Salmon, Proc. Zool. Soc, London, 1913, 

 pp. 572-610. 



