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THE ROYAL SOCIETY OF CANADA 



The percentage of males and females in the 5-year fish at Rivers 

 inlet are exactly the same as Gilbert obtained in 1913 and 1914, but 

 the percentages for the 4-year fish are more nearly the exact reverse 

 of these for the 5-year fish than he has found in any of the years, 

 hence, it is more definitely indicated that the lack of females in the 

 4-year fish is nearly equalled by the excess in females in the 5th year. 



These percentage differences in type and in sex serve to distin- 

 guish the Rivers inlet run from the Fraser river run, but they do not 

 help in distinguishing the individual fish, and here the differences are 

 more marked than in the whole run. Gilbert has pointed out that the 

 fresh water growth in the Rivers inlet fish as well as the first year 

 growth in the sea is much less than that of the Fraser river fish, but 

 this is compensated by the growth in the second year at sea. A com- 

 parison of the annual growth calculated from the scales makes this 

 distinction much more vivid. Tables of growth during each year and 

 of the length at the end of each year form the best basis for such com- 

 parison. In the calculation 1-2 inches is taken as the average length 

 of the fry when the first ring is formed around the nucleus of the 

 scale. 



Rivers Inlet — 1 Year Stream 



Fraser River, 2 yr. Stream 



1 Year Stream 



4th 

 5th 



Average . 



