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THE ROYAL SOCIETY OF CANADA 



Fig. 5. — Spring — stream type. 2nd year growth. 



The average growth in the uncompleted year of the 2-year class 

 was 8-7, of the 3-year class, 6-2, of the 4-year class, 4-3 and of the 

 5-year class, 3-2. The growth in length for any year of life differs 

 less in the stream run forms than the sea run forms, largely because 

 since the growth in the fresh water is slow there is but little difference 

 in length of those when the growth of the second spring starts, no 

 matter what time of the year they were hatched, and thus having a 

 similar start there is more likely to be more sameness throughout. 

 In the sea run fish, however, since there is a great variation in the time 

 the eggs are hatched there is great variation in length when the first 

 winter begins and hence when the rapid growth starts the second year. 

 Thus, variation is likely to be continued throughout life, although there 

 may be individual cases where a fish, small in the second spring, if 

 it is in good health, may get a better chance to feed well and may be- 

 come a large specimen of the class by the time it is four or five years 

 old. Similarly, a fish, large when young, may not keep up with the 

 growth rate of its class but may be a small fish when it becomes mature. 



The frequency curve shows a range in the first year of the stream 

 type fish from 3-0 to 4-2 inches. The second year growth varies 

 from 8-5 to 13-7 and the length at the end of the second year from 

 12-3 to 17-2. The numbers for the other years are not sufficiently 

 numerous to give satisfactory graphs. 



In both sea-run and stream-run fish the males are slightly in 

 the majority and almost to the same extent, but this is maintained 

 by the much greater number of males among the younger fish caught. 



