246 BRITISH FRESH-WATER FISHES 



was done under the old system, but their takes are far larger, 

 because the running fish are increasing every year in numbers, 

 owing to discriminate fishing. From ordinary netsmen, 

 discrimination cannot be expected. Fierce rivalry exists 

 among them ; every stone which may shelter a fish or obstruct 

 the net is removed from the channel, and the nets are worked 

 with an industry that could not be exceeded if salmon were a 

 dangerous beast of prey which it were desirable to exterminate. 

 Therefore, in the interests, not only of themselves, but of the 

 persons employed on the nets, upper proprietors must provide 

 means of escape for a due proportion of each run of salmon 

 entering their rivers. Most of the rivers in North Britain and 

 in Ireland lend themselves to water-storage. Their head- 

 waters generally run through uncultivated land of little value ; 

 in very many cases, like that of the Helmsdale, there are Jakes 

 whereof the level may be raised by dams at the expense of 

 inundating nothing but moor and bog. 



River proprietors are spending more and more upon 

 artificial salmon-hatcheries, in the belief that therein exist 

 the means of replenishing exhausted rivers ; but it is obvious 

 to those who have watched most closely the operations of 

 Nature that, in order to have any effect, artificial hatching 

 must be carried out upon a very considerable scale. Until 

 one has watched the smolts descending to the sea in any 

 ordinarily prolific salmon river, no conception can be had of 

 the profusion of Nature's provision for maintenance of the 

 species. These little fish have survived the initial and tender 

 stages of alevin and fry ; they represent but a small fraction 

 of the produce of a single spawning season ; yet they are in 

 countless swarms ; in places the water is blue with them. In 

 most existing hatcheries no attempt is made to rear the fish to 

 this comparatively robust stage. It is considered that enough 

 has been done if, say, half a million defenceless fry are liberated 

 to take their chance among hostile beasts and birds, fish and 

 insects. From hatcheries where provision is made for rearing 



