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 lakes 
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. ‘hese 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 
— ow 
