IN the reports from our angling centres which appear every season in the columns of the Press, we are constantly meeting with an old familiar friend, the ferox, or the salmo ferox—on one occasion even the silver ferox; and should the question arise, let us say in the smoking-room of some Highland hotel, as to what a Ferox is, the reply will usually be something to the effect that it is a peculiar species of trout found only in certain large and deep lochs, growing to a great size, and of such innate ferocity as to deserve the specific title that has been affixed to it. Are there any grounds for this wide-spread belief in the existence of a distinct species—the so-called Ferox?

The extremely plastic nature of the whole family of Salmonidae is well known to all anglers and naturalists who have made any study of the question. It is doubtful whether any other family of vertebrates is so easily influenced and altered in outward appearance by the varying conditions of its surroundings. Hence, there have always existed the most divergent views as to the question of the number of species in this family. Thus, in 1836, Yarrell enumerates six separate species of British Salmonidae, including not only the Great Lake Trout or ferox, but also the par, not at that date recognised as being merely the early stage of the Salmon. So also Jardine in 1839; while Agassiz already in 1834 admitted only three species, the salmon, the sea trout, and the common or brown trout. But the passion for the sub-division of species seems to have an extraordinary attraction for some minds. In the British Museum Catalogue of Fishes, 1886, Dr. Gunther divided the genus Salmo into no fewer than six migratory or anadromous, and six non-migratory or freshwater species, among which latter, of course, the ferox figures. On the other hand, Dr. Francis Day in British and Irish Fishes, 1880-4, - a work which to this day holds its position as the standard authority-reduced the number to three: the salmon; the sea trout, with its varieties, as the brown trout, Loch Leven trout, etc.; and the char; thus showing close agreement with the views of Agassiz, published half-a-century earlier.

Now in order to determine the question as to whether a certain form is entitled to specific, or merely to varietal rank, it is first necessary to define with exactitude what it is that constitutes a species; and it is very doubtful whether a better or more authoritative definition can be found than that adopted by Dr. Day.

'I shall consider species among the true Salmons to be an assemblage of individuals which agree together in their structure, and in the development of the sexes, but differ in some structural character from all other fishes.'

Taking, then, this definition with its weighty authority as our test, let us proceed to enquire in how far the so-called separate species Salmo ferox fulfils its requirements.

The structural characters which have been chiefly relied on as indicating specific differences in the varying forms of our Salmonidae are chiefly as follows. The number of vertebrae; - now of these, according to Dr. Gunther, the number in the common or brook trout ranges from 57 to 60, and in Salmo ferox from 56 to 57; but Day records instances in undoubted brown trout where they ran from 56 to 60. So, too, with the number of caecal appendages, of which Gunther assigned 43 to 49 to ferox, and from 33 to 47 to fario; but Day found instances of from 33 to 61 caeca in the common trout; so that the inconstancy of these tests is at once apparent. The same result is also arrived at in the next proposed test, viz. the number of rays in tail and fins; as well as in another relating to the arrangement of the vomerine teeth. In both these latter cases, the results are again so varied and inconstant as to make it evidently impossible to base any safe conclusions thereon as to specific differences. Colour will be at once admitted by all to be a hopeless test; all know the infinite variety of coloration and marking in trout from the same lake, or even from the same pool of a river. We come, then, to this, that after the most painstaking researches by many eminent naturalists, no one constant and certain difference of structural character has been discovered as between the brown trout and the so-called ferox.

If one listens to gillies and boatmen no doubt one will be told of various infallible methods of distinguishing the `ferok' from the 'trout,' but the curious point is that no two of them will be found to agree upon the matter. I remember well my own first experience with such a fish, many years ago upon Loch Awe. Rowing down to the 'Crow Island' a short thick handsome trout of some 5 or 6 lbs. weight was caught, and at lunch time on the Island it became the subject of animated debate among the boatmen there assembled ; but the question was set at rest-at least to their satisfaction-by the dictum of the oldest, who pronounced it to be most certainly a`ferok,' 'because it had five large black spots on the gill-covers.' It seems to have come to this on some Highland lochs, that any trout above a certain weight caught by trolling must be a ferox; if caught on a fly it is a `trout.' But apparently the necessity of some considerable weight is now abandoned ; for a ferox of 1 1/2 lbs. has before now been recorded, and in a recent report from Lairg six ferox weighing together 1 1/2 lbs. are mentioned.

The most convincing proof to me, however, is that it has been my experience to see the great so-called ferox developed in a few years from the insignificant fingerling - trout of a Highland hill burn. Just thirty years ago a party of anglers found themselves, as was their wont, on a summer holiday in Sutherland; and the weather being too fine for fishing, it was resolved to carry out a long-deferred intention of 'stocking' with trout a chain of three small lochs lying high up on the hills, and till then absolutely devoid of fish-life. Some 150 little brown trout were caught high up in a precipitous mountain burn where no spawning trout from the large loch below could possibly ascend, and were duly liberated in these little lochs, the average weight of the little trout being some 7 or 8 to the lb.

Twelve months later one of these trout was caught-a bar of burnished silver, and weighing just 1 lb. Another year passed, and again the `wee lochies' were visited, and again from the very same projecting rock and by the same hand (now alas ! long still, a trout was hooked and safely landed, of which the counterfeit-presentment lies before me. Just 19 1/2 inches long, perfect in shape and colour, it weighed 4 1/4 lbs. But mark the sequel, which may best be told in the words of a letter from Mr. J. A. Harvie-Brown, read at a meeting of the `Scottish Fisheries Improvement Association' in 1884 he having been, with me, a member of the party who originally stocked the lochs:

'They developed huge fins and square or rounded tails, lost all spots, took on a coat of dark slime, grew huge teeth, and became " feroces " in that short time. The common burn trout, taken from a very high rocky burn up in the hills, in two years became indistinguishable from Salmo ferox. The first year they grew to about 1 lb. or 1 1/4 lb., took on a bright silvery sheen of scales, were deep and high-shouldered, lusty and powerful, more resembling Loch Leven trout than any others. This was when their feeding and condition were at their best ; but as food decreased and they rapidly increased in number, spawning in immense quantities, and with no enemies, the larger fish began to prey upon the smaller, grew big teeth, swam deep and lost colour, grew large fins and a big head, and became Salmo ferox so-called. In two years more the food supply became exhausted, and now (1884) the chain of lochs holds nothing but huge lanky kelty-looking fish and swarms of diminutive " black-nebs," neither of the sorts deserving of the Anglers' notice.'

In the large lakes of the Continent a trout is found growing to a great size sometimes termed Salmo lacustris; and Berkenhout (1795) supposes, probably with truth, that our 'Great lake Trout' is identical with it. Jardine and Selby, with the tendency to subdivision of species so prevalent in their day, gave to it the specific name of S. ferox; but Moreau observes that ‘la truite feroce, Trulta ferox, est une simple variété de la Truite vulgaire et nullement une espèce particulière.’ Dr. Day, after all, our best authority to this day, comes to this very distinct conclusion:

‘In fact the Great Lake Trout of Geneva is the Salmo ferox of lakes in Wales, the North of England, Scotland and Ireland, and merely a form of our fresh-water trout.’

It has been sufficiently shown, I would think, that the so-called Salmo ferox agrees in structure and in the development of the sexes with the ordinary brown trout, and differs from it in none of these points, the test with which we set out at the beginning of this inquiry; but once an error has taken root it is proverbially difficult to eradicate it. And so long as it is a matter of self-interest to hotel-keepers, boatmen, and others to proclaim that their waters hold a rare fish of great size and ferocity, just so long may one expect to meet with our old friend the ferox.

Meantime it may be asserted, without fear of contradiction, that the unanimous opinion of modern scientific authorities is that in Great Britain and Ireland we have, in all its varied forms, but one species of fresh-water trout, Salmo fario.