126 THE LIFE OF THE SALMON 



rivers for a very long period ; but it is quite possible, 

 and I would venture to say in many cases very 

 probable, that the cause of the late character has 

 nothing whatever to do with the physical conditions 

 of the rivers, but is purely the result of the influence 

 of man in his treatment of the fisheries, and that as 

 the treatment has continued on the same lines within 

 the memory of man, so no one has ever known or 

 heard of early runs of fish in those rivers. One might 

 instance the case of the river Leven, which flows 

 out of Loch Lomond into the Clyde at Dumbarton. 

 This river has for a very long time been considered 

 a late river, and there are old records of Dumbarton 

 fisheries which point to this conclusion. A thriving 

 dyeing and bleaching industry has long been estab- 

 lished, gross pollution has resulted, and net fishing 

 at the mouth of the river has been steadily carried 

 on. But of late years an active and I may add a 

 philanthropic angling association, which allows all 

 anglers to participate in the sport which the loch 

 afibrds, has done something to improve the general 

 conditions and the stock of fish, with the result that 

 early fish are appearing. In other cases where 

 serious over-fishing has been allowed to continue 

 rivers have naturally acquired a late character. With 

 over-fishing, or other causes of reduction of breeding 

 stock, the first class of fish to disappear is the spring 

 run. We are therefore not safe in presuming that 

 in all cases when we do not find a spring run the river 

 is a late one. We must satisfy ourselves first that the 

 river has every chance of bearing a full stock of fish. 

 In Scotland — and concerning questions of tem- 



