SALMON-FISHERY OF SCOTLAND. 21 



wonderful instinct explore their way to their parent stream. From 

 the sea they run to the Tay, from the Tay to the Isla, and through 

 that river for several miles, till they come to the junction of the 

 Ench, where, without exception, every fish ascends, and then leaves 

 the Isla, none going up it further. Those spawned in the Linth are 

 known to take their course up the Rhine ; out of that river up the 

 Aur, through the lakes of Zurich, and so into the Linth. In like 

 manner, through various rivers, lakes, and windings, they push up 

 to the very interior parts of North America, on purpose to breed in 

 the natal waters.* There are, however, some instances of animals 

 mistaking their instincts. The flesh-fly has been seen to deposit its 

 eggs in the flower of the fetid stapelia, deceived by the resemblance 

 of its smell to that of carrion. So I have known salmon to run up 

 rivers in which they were not bred but this seldom occurs. I re- 

 member a circumstance of the kind when angling in the Ench. I 

 caught a salmon, whose figure appeared to me very singular. It had 

 a hogged back, something resembling that of a perch. I showed it 

 as a curiosity to a fisherman who was near me, and asked him if he 

 had seen the like before 1 His reply was, Yes ; that is a Tummel 

 fish : it has lost its way and strayed up here." 



Another acute observer f of the nature of fishes remarks, 



"Salmon, it is well known, form gregarious associations, into 

 which only those are admitted which belong to the same tribe or 

 family. So much is this the case, that the salmon of one river is 

 never known to run up another, though they might easily mistake 

 their way when the streams are muddy. As an example of this, it 

 may be stated that the rivers Forth, Teath, and Allan, form a junc- 

 tion near Craigforth, and each contains salmon that are easily dis- 

 tinguishable, both in size and shape, from the others ; yet the salmon 

 of one of those rivers are never known to enter the others, though 

 the streams are often swelled from excessive rains," 



In the same way, another writer,J a practical salmon-nsheiv 

 who had the fact daily under his eyes, states, 



" That every river, in which salmon are bred, has its own peculiar 

 fish, and that the salmon of one river differ in appearance from those 

 of other rivers, are facts known to every person in any degree ac- 

 quainted with the salmon-fishery. In proof of this it may be men- 

 tioned, that the river Berridale in Caithness, of which I am tenant 



* 8ir Alexander Mackenzie's Travels. t Survey of Forfarshire. 



+ Prize Essay*. 



