ON SALMON. 



41 



If we examine this table we find that the average weight we have found 

 for the various age classes is different in the different localities. If we 

 disregard the question of the correctness of these average figures, and also 

 the fact that the fish in the corresponding age-class may not all have been 

 caught in exactly the same period (perhaps also may not have been hatched 

 or may not have migrated at exactly the same period of the year),* we still 

 find that salmon of corresponding age-classes are not of the same size 

 throughout the whole country. Nor are they of the same size in different 

 years. 



If we put this in tabulated form it becomes clearer. 



FISH WITHOUT SPAWNING MARK. 



An exact determination of the growth of salmon for the whole country 

 can therefore not be obtained on the basis of this material. We cannot do 

 more than say that the growth appears to vary within the limits mentioned 

 above and shown in this table. 



If we examine the table on page 40 we find also that the relation between 

 length and weight is different in different localities. Herr Landmark has 

 previously endeavoured to demonstrate this fact by weighing and measuring 

 salmon whose age was unknown. Now that we can separate the fish into 

 groups according to their age this difference is confirmed, but it is not a 

 difference of great magnitude. 



It was hoped that one could establish the fact of race characteristics 

 with the aid of the variations which a comparison of weight and length 

 showed to exist in various localities. If we examine the table carefully it 

 appears that there is not much probability of this. 



If we examine the one winter old fish from Christiansand, where the 

 material was largest and the most reliable, we find that in 1908 they were 

 56'2 cm. in length and weighed 16'8 hectos, whereas in 1909 they were 



* With a fish which grows so rapidly as the salmon considerations of this sort are 

 bound to affect the average. 



