8: 



The Salmon 



water, i.e. from the time a clean tish enters fresh water until it returns 

 to the sea. Some of them are a whole year in fresh water before 

 spawning, and, as nearly as I can make out, lose twenty-five per cent 



Fig. S4. — 14 lbs. 27th Mavch. 



of their weight before and after this takes place ; so that a fish of 20 

 lbs. leaving the sea on 1st January 1907 is reduced to half that weight 

 on its return as a kelt on ist January 190S. This percentage varies 

 with the length of time the fish is in fresh water, and according to the 

 river it frequents. 



