tRESH-WATER TROUT— COLOURS OE. 185 



Golov/rs. — Yarrell observed, respecting tlie distinctions of British SalmonidEB, 

 "too much reliance has been placed upon colour without resorting sufBoiently to 

 those external indications founded on organic structure, which may with greater 

 certainty be depended upon." Examples of brook trout have been often found 

 on migrating to the sea, to assume the brilliant silvery livery of the migratory 

 Salmonoids, as well as their x -shaped spot. Mr. Harvie-Brown remarked, June 

 12th, 1882, on having captured at Darness several so-called sea trout from a sea 

 pool or first pool at the mouth of the river, fresh-water at low tides, salt or 

 brackish at high tides. Erotn their silvery appearance they were known as sea 

 trout, but were the river form acclimatized to brackish or nearly salt water, or 

 periodically visiting such between tides. 



Many observers have remarked upon the fact that fresh-water trout may live 

 in salt water. Mr. Francis Francis, in The Field, May 10th, 1879, stated that 

 when introducing salt water into a tank in the Brighton Aquarium, which was 

 inhabited by some salmon par, there was at the time among them a common trout. 

 It, too, took to the salt water very kindly, fed smartly, and grew rapidly. 

 "Aquarius," in The Field, July 11th, 1885, stated he had seen the brown 

 trout, Salmo fario, taken in the open sea, as have many others ; while, that 

 specimens still having their fresh- water dress are occasionally captured in the sea 

 or brackish waters, is known to most persons who fish these latter localities. 



I think the foregoing tends to show that the silvery sterile Loch Lomond trout 

 is simply a variety in colour of the common fresh- water species ; that this colour 

 has been observed in sterile forms previously ; that our brook trout may be found 

 in salt water as well as in fresh without deleteriously affecting its health ; that 

 local geological conditions or states of the fresh water in which trout live has like- 

 wise been observed to produce this result in their colour ; and, in short, that our 

 pretty speckled brook trout may change into a silvery and anadromous form, 

 ascending rivers at certain seasons in order to continue its kind. 



I have already (p. 145) shown that silvery forms like sea trout may be found 

 permanently residing in fresh water, that our speckled trout may live in salt 

 water and take on the silvery livery of the marine anadromous form, and we now 

 come to the changes perceptible when living in the streams and lakes of the 

 British Isles. For the colours and forms of our fresh-water trout are very 

 dissimilar, at a first glance few would believe that the silvery Lochleven, the 

 large Thames trout and the puny residents of Cornish streams were all one and 

 the same species. While, forty years since, Stoddart in his Angler's Companion, 

 1847, p. 3, remarked that " unquestionably there exists no species of fish which, 

 judging of it by the external marks, holds claim to so many varieties as the 

 common fresh- water trout. In Scotland almost every lake, river, and streamlet 

 possesses a breed peculiar in outward appearance to itself."* 



the sea can hardly be correctly defined as " low hill streams." Secondly, as the fish have 

 bred on these Madras Hills, the experiments can scarcely be classed among failures. Eespeoting 

 this last, opinions may possibly differ, but that trout have been introduced into the streams on 

 the Koondahs ought to be recorded, or at some future date on examples being captured another 

 species may perchance be added to the present superabundant supply I 



* Lord Home in Yarrell's Fishes observed of two streams, the Whitadder and its tributary 

 the Blackadder, that the first flows along a very rocky and gravelly bed, while the latter rises in 

 mosses, also goes through them in the first half of its course, but subsequently along a rich and 

 highly cultivated district. The trout in the first are silvery in colour, worthless as food : while 

 those from the Blackadder are dark with orange fins, but their flesh is excellent. The many 

 varieties are dependent upon external causes and chiefly to the abundance or the reverse of food 

 and the nature of the water they reside in or the soil over which it flows. Knox, Lone Glens of 

 Scotland, 1854, p. 10, remarked, "In Scotland there are at least four distinct species of trout." 

 He then enumerated from an angler's point of view the following seven which he recorded as 

 separate species : " 1, the dark-spotted lake trout. 2, the red-spotted estuary trout : these are the 

 best of their kind, they have pink-coloured flesh and are excellent to eat. 3, the red-spotted 

 common river trout, with pale flesh and tasteless. 4, the pink-coloured red-spotted common 

 river trout, chiefly found in England. 5, the par-trout, rather better, when fed in certain rivers, 

 than the common red-spotted trout, but never equal to the pink-coloured fish. 6, the dark- 

 spotted river trout, of whose natural history I know but little, although I believe such a trout 

 exists. And 7, the Salmo ferox or great lake trout of the north," 



