42 THE AGE AND GKOWTH OF SALMON AND TEOUT. 



much shorter and nevertheless were heavier. This is also the case if we 

 examine the two winters old fish from the same locality. The yearly varia- 

 tion in the proportion of weight to length in the same district can therefore 

 be so large that one year may show just the contrary to another year. It 

 would therefore involve us in many difficulties if we attempted to establish 

 this proportion as a means of studying the question of race. 



There is yet another point, on which the average figures which we have 

 collected in our table on page 40 give us clear elucidation. That is the 

 proportion between the growth of maiden fish and that of fish whose scales 

 have spawning marks, and which, therefore, have returned to fresh water 

 on a previous occasion to spawn. 



As an example let us take the figures shown in the table for Christiansand 

 in 1909. 



This table shows us quite clearly what a serious check the spawning 

 journey and the actual spawning itself put on the growth and the weight of 

 the fish. Whereas two winters old fish which have never spawned are 

 73 cm. long and weigh 41 hectos, fish of a corresponding age, but which 

 have spawned in the previous winter, are not more than 61'2 cm. long and 

 weigh only 22'9 hectos ; and whereas a three winters old maiden fish is 

 91*3 cm. in length and weighs 88 - 4 hectos, a salmon of the same age, but 

 which has previously spawned, whether in its second or third winter, is 

 only 75*1 cm. in length and weighs on the average not more than 

 42*7 hectos ; that is to say, little more than a maiden fish which has been 

 a year less in the sea subsequent to migration. 



This clearly shows how great is the retrograde influence on the growth 

 of the salmon of the act of spawning and of the difficulties and privations 

 connected therewith. 



It is easy to see that this must be the case, for while one salmon 

 remains in the river for many months, fasting and becoming emaciated, on 

 the other hand the unripe fish of corresponding age remains in the sea, 



