The Salmon 



the number of rings one must be careful to remember that while grilse 

 and salmon are in fresh water no addition to the number of rings takes 

 place. On examining the scale carefully where the new rings join on 

 to the old, we find a dark line round the plain part of the scale. This 

 is where the new ring begins. 



FIG. 65. 10 Ibs. igth February 1907. 



During winter, when the fish is in the sea, the rings become con- 

 tracted, and this is caused, I think, by the food-supply becoming scarcer 

 during the cold weather. This dark mark must not be confused with 

 the dark mark that is made while the fish is in fresh water, caused 

 by the breaking of the scales, which takes place every time the 

 iish returns to fresh water, and is afterwards clearly shown on the 

 scale. It is, however, seldom seen more than three times. Every 



