DECAY OF SALMON. 117 



to be luisteiiiug to the same end from similar causes. 

 That part of the evil which consists in obstructions can 

 be easily removed, or at least greatly alleviated. That 

 which consists of pollution is more difficult to deal with, 

 but it demands and must very soon receive abatement, 

 on considerations even more important than the preserv- 

 ation of salmon, though that may seem to be a strong 

 expression. 



The killing of spaiv7img Jish in close-time has been 

 and is a great cause of decrease, but it can scarcely be 

 regarded as a cause of the decrease within the dates 

 at which we are now chiefly looking. This destruc- 

 tive practice is not new and increasing, but old and 

 diminishing ; and it is plain that we cannot ascribe an 

 increased and increasing effect to a diminished and dimin- 

 ishing cause. ]]ut, though this practice cannot account 

 for the decrease in the number of fish compared with 

 former periods, it is no less true that it is a great evil, 

 the suppression of which would bring about an improve- 

 ment on our present returns. It is, indeed, to the 

 diminution of this practice of late years that we chiefly 

 ascribe the fact of the supply of grilse or young fish 

 having been so well maintained during the last twenty- 

 live or thirty-five years, in spite of the increased severity 

 of the fishing, shown by the rapidly diminishing number 

 of the fish which are allowed to come to the adult 

 stage. 



Another cause of decrease has been the brevity or mis- 

 timing of the close season. Up to 1 8 5 8 there were three 

 different close seasons in Scotland — for the Solway (with 

 several differences for the different rivers emptying 



