RAPID GROWTH OF SALMON. 23 



second return to his native stream, will weigh from nine to 

 sixteen pounds weight, at which period," he says, " the 

 fish can be only two years old." What may we not hope 

 from this circumstance, if we resort to the artificial pro- 

 tective principle I am advocating ? 



Regarding the period called fence-months, I must 

 strongly recommend that, in all salmonries, the strictest 

 protection shall be given to the brood at the time when 

 they are going down-stream for the sea ; for it is at that 

 critical period that the skilful fly-fisher can, with very little 

 trouble, fill his creel with the smolts or young salmon, who 

 would, if not thus untimely taken, become grilse in about 

 four months more. The destruction done by these fisher- 

 men may be computed when I mention that, if they make 

 use of many flies at the same time, smolts will be taken by 

 every hook. Again, on the return of the fish from sea, the 

 shameful practice of placing pots, as they are termed, in 

 the narrow passes at the mouths of rivers, ought to be done 

 away with : in the first place, because they retard the pro- 

 gress of the fish ; and, in the second place, they afford a 

 favourable opportunity to the porpoise, which feeds largely 

 upon salmon. If this system of pots were set aside, the 

 porpoise would not be able to follow them up and take 

 them so easily in the brack water. A curious instance of 

 the perseverance of a porpoise, when chasing his prey, oc- 

 curred a few years since off the Isle of Dogs, in the Thames. 



