254 



BULLETIN OF THE BUREAU OP FISHERIES 



incidental check) may be seen. Still a third break is to be found at 35 rings. From 

 this point there is a gradual widening of the rings into the rings of rapid growth of 

 the second year. Following this second summer's growth is a band of closely spaced 

 rings representing the second winter. This is followed in turn by the rapid growth of 

 the third summer, the third winter check, and finally by a narrow marginal band of 

 more widely spaced rings of the fourth summer. The last band and in some places 

 even the third winter check have been removed Ity absorption. 



An inexperienced observer might find difficulty in determining which check on 

 this scale represents the first winter. If he decided upon the second check (at 15 

 rings), he would be forced to consider the third ch(H-k (at 35 rings) as representing 

 the second winter. His interpretation then would be that the fish was in its fifth 

 rather than its fourth year. An experienced observer would not have this difTiculty. 

 His interpretation would be based upon a knowledge of the general nature of the 

 different types of nuclei and the impression he gained from the appearance of the 

 whole scale, neither of which is described easily. In this particular case the portion 

 of the scale inclosed by the second check does not resemble a stream nucleus and it is 

 too small to represent an ocean nucleus. Futhermore, the hand between the second 

 and third checks (in comparison to the other summer bands) is too narrow to represent 

 a second year's growth in the ocean. Even a relatively inexperienced person probably 

 would interpret correctly the age of this scale if he compared it with a series of scales 

 of the same general type. 



Table 30. — Chinook salmon marked at Big White Salmon Riner hatchery during the spring of 1923, 

 when approximately S months old, and recovered during the seasons of 1924, 1925, and 1926 



