At this stage of our inquiry the possibility that salmon seize a lure from some motive other than hunger has nothing to do with the case. The real questions are: Do salmon in fresh water ever, before spawning, take a lure with intent to eat? and, if they do, how often ?
There is some reason for fearing that, in common with many a new theory, the doctrine we are considering is pushed to an unwarrantable extreme. The habit of exclusive opinionativeness is entertainingly observable in connection with subjects of wide variety. It is that of a class of persons who on every occasion like to feel themselves, in virtue of peculiar insight, other than the commonalty. "Alcohol is a poison!" vows Sir Frederick Somebody; whereupon all precisians know, with pride of the seclusive spirit, that Mahommedan liquors are the only fit drink for those who are not by long heredity inured to stronger potions. "The race is degenerate !" shouts Sir Somebody Else; and, instantly, to perceive the race degenerate becomes a modish mark of knowledge. "People forget that society is a living and growing organism," says The Times, impatiently; and thereupon the intellectuals go about pessimistically scorning the populace for not knowing that they are something other than themselves. The comparatively new theory about the salmon seems to belong to the class of opinions of which these dogmas are contemporary examples. It is novel. It is not a theory such as an ordinary person would arrive at by himself. To adopt it is to be enlightened, notable, detached from the deplorable ignorance of the times; if to be disillusioned also, it is bracing mentally and morally, as giving one something to endure in behalf of Science struggling against the errors of the age. To push it to an extreme is to allow the foible to run the usual course.
Sir Herbert Maxwell, we have seen, cites a case in which a salmon rising at a lure was moved by desire to eat. Why does he treat it as exceptional ? That, as I shall endeavour to show, is a crucial question. Let us suppose that the fisherman had not seen the butterfly; that simply it had occurred to him that a Mayfly might prove appropriate to the size of the river; and that the Mayfly raised the salmon. How would Sir Herbert have interpreted the incident then? Would he have said that the fish rose with " gustatory intent" ? It is safe to feel assured that he would not. He would not have perceived in the incident anything to disturb his understanding that it is not in the expectation of something to eat that salmon rise at flies. Not knowing all, he would not have understood all. A salmon caught on a Mayfly! He would have been more than ever confident that it is not to appetite that any selection from the tackle-book makes appeal. It is probable, indeed, that he would have regarded the incident as a dramatic proof of the theory that salmon do not rise to feed. The accident of his knowing about the butterfly enabled him to interpret the matter truly. When, in such cases, is our knowledge approximately complete? Sir Herbert Maxwell would be the last to say that it is so often. The most vigilant eye cannot detect all that happens on even a few yards of salmon river. Reviewing his successes with the fish, Sir Herbert would be able in only a very few instances to be sure of what it was that attracted one on the occasion of the rise immediately preceding that which set his rod a-quiver. In only a very few instances, that is to say, could he speak with certitude about the intent with which the salmon rose. Judicially considered, the entertaining case which we have been examining is a remarkable evidence of how little, apart from abstract theory, there is to be said for the notion that " gustatory intent" is as a rule not among the impulses at the bidding of which salmon seize a lure. It leaves us perfectly free to imagine it possible that the desire for food, or at least an assumed desire, is as often as any other feeling the motive of a salmon's action.
Among sportsmen who like their craft to be scientific it is not only Sir Herbert Maxwell who issues indeterminate reasoning. There is Dr. Barton also. After the imposing array of authoritative citations in favour of the theory that salmon fast when in fresh water, he remarks that "practical sportsmen know well enough that it is only after fatigue that salmon can be at all tempted, and that the appetite only remains a few hours or days at most after a fish has moved up into a new pool.1' This reads as if Dr. Barton were admitting an insignificant exception and triumphantly establishing his theory of a general rule. The implications of his statement are that salmon do not move about very much; that when they find a comfortable pool they tend to tarry; and that, flitting infrequently, being fatigued only on rare occasions, it is only on rare occasions they incline to rise. The rarity of rises most fishermen will admit; but at present that is not exactly the subject. What we have to consider is whether salmon are as slothful as Dr. Barton assumes. Are they ? Does each fish, when it arrives from the sea, find a holt to which he is as devoted as the trout is to his hover? It chances that, at the instance of Mr. Augustus Grimble, an observant sportsman of much experience, this question has been the subject of an enlightening discussion. Mr. Grimble doubted the accepted understanding that salmon, when they run into the rivers, quit the sea for months, and ultimately became convinced that the suspicion was justified. The evidence was derived from what happens in a West-of-Scotland stream. Often during the season there is very little water, and not a salmon is to be seen; but when the rains come upon the mountains the stream swells and salmon swarm. Where were the fish in the time of drought? Mr. Grimble could not but think that they had dropped down the stream. A gillie who knows the water well bore picturesque witness encouraging to this conjecture. Until 1850, when the Fishery Board began to do its duty, the cottagers were wont to take enormous baskets of salmon and sea-trout from that stream, and the means of capture which they used showed that they too held the theory broached by Mr. Grimble. They built " an oblique but not high dyke of stones across the river, which they repaired as each spate damaged it. They were fully alive to the fact that the fall of the water, not its rise, was their opportunity. As each spate came, the ascending fish easily swam over the low dyke, to mass themselves together in the pool immediately below the impassable fall. As the flood subsided, and the volume of water rapidly diminished, the whole body of fish began to drop back to the sea-tail first, as is their usual mode of descent;- then, meeting the dyke, with its top wall above water, they coasted along it until they arrived at cunningly prepared openings at either end. These traps were less than a yard in width, deepened for the purpose, and fitted with rough nets, into which many of the descending fish dropped." That seemed to leave but little room for questioning. Apparently it showed that salmon ran into the stream when a flood came, and dropped back to the sea when the flood was falling. If this were so, and the rule were general, the discovery would be important. In framing the fishery laws, Parliament, as Mr. Grimble says, never contemplated that salmon should incur the danger of the estuary nets more than once a year. Therefore, if Mr. Grimble's theory were acceptable, there would be a strong case for amendment of the laws by considerably curtailing the privileges of the net fishers. If salmon run up and down the rivers with every flood, Parliament acted under a serious misapprehension in deciding what scope could be safely given to the nets, and inadvertently arranged for a gradual diminishing of the stock of fish. The question was, Could Mr. Grimble's theory be accepted ? There was a good deal to be said in its support. The gillie declared that in the days of plenty " several hundreds of salmon could always be seen swimming in the sea round the mouth of the river; that in periods of flood this school came up the river, and could no longer be seen in the sea; and that, as the river fell, and the fish returned to the sea, this school was seen again, in diminished numbers, hanging about the salt water at the mouth." Then, there was Mr. Grimble's own experience. Between September 1 and September 9, not fishing every day or carefully, he caught five salmon. Whence had they come ? For three days before, the stream had been without rain, " and the bottom of every pool could be as clearly seen as if it were dry land." During the time of low water he had searched the whole stream, and had not come upon a single fish. " I think, then," Mr. Grimble wrote, " it may be taken as proved that fish do ascend and descend some rivers several times in the course of a season." Discussion of Mr. Grimble's theory did not leave it quite intact. It turned out not to be applicable to all rivers. These may be regarded, broadly, in three classes. There are large rivers, such as the Dee, the Tweed, the Shannon, the Avon, and the Tay; considerable streams which are tributaries to rivers of the first class; and self-contained small ones, of which that on which Mr. Grimble had been fishing was an example. It was shown that after entering a river of the first class salmon stay there until they have spawned, and that salmon in waters of the second class drop down to the main streams in times of excessive drought. Mr. Grimble's theory, however, was perfectly true as regards many rivers of the third class. As the streams rise and fall the salmon do undoubtedly move up and down. Now, what are these streams ? The class includes a few in the West of England, a few in Wales, and nearly the whole of the salmon rivers in the West of Scotland. As to the variability of their volumes there cannot be any doubt. One of the best of them, the Add, in Argyllshire, has been described by Mr. A. E. Gathorne Hardy as "just an ordinary type of West Highland stream, only fishable with any prospect of success immediately after a spate," and "hardly in fishing order for more than a couple of hours."