154 THE SALMON RIVERS OF SCOTLAND 



spring advanced great numbers of fly larvae were hatched out in the 

 filter and from it were carried to the hatchery, the greatest numbers 

 being carried to the tank which received the effluent alone. 



From the successful results of this experiment, I think we are 

 justified in deciding that a solution has been found for the worst 

 kind of river pollution problems in Scotland. 



