Classification of Fish—Their Form and Colour—Mode and Means of Life—Curiously-shaped Fish—Senses of Smell and Hearing in Fish—Fish nearly Insensible to Pain—The Fecundity of Fish—Sexual Instinct of Fish—External Impregnation of the Ova—Ripening of a Salmon Egg—Birth of a Herring—Proposal for a Marine Observatory in order to note the Growth of our Sea Fish—Curious Stories about the Growth of the Eel—All that is known about the Mackerel—Whitebait: is it a Distinct Species?—Mysterious Fish: the Vendace and the Powan—Where are the Haddocks?—The Food of Fish—Fish as a rule not Migratory—The Growth of Fish Shoals—When Fish are good for Food—The Balancing Power of Nature.

Fish form the fourth class of vertebrate animals, and, as a general rule, they live in the water; although in Ceylon and India there are found species that live in the earth, or, at any rate, that are able to exist in mud, not to speak of some that are said to occupy the trees of those countries! The classification of fishes as given by Cuvier is usually adopted. That eminent naturalist has divided these animals into those with true bones, and those having a cartilaginous structure; and the former again are divided into acanthopterous and malcopterous fish. Other naturalists have adopted more elaborate classifications; but Cuvier’s being the simplest has in my opinion a strong claim to be considered the best; at least it is the one generally used.

A fish breathes by means of its gills, and progresses chiefly by means of its tail. This animal is admirably adapted for progressing through the water, as may be seen from its form, which has been imitated more or less closely by the builders of ships, the makers of weavers’ shuttles, and others. Fish are exceedingly beautiful as regards both form and colour. There are comparatively few persons, however, who have an opportunity of seeing them at the moment of their greatest brilliancy, namely, just when they are brought out of the water. I allude more particularly to some of our sea fish—as the herring, mackerel, etc. The power of a fish to take on the colour of its hiding-place may be mentioned. I found, a few weeks ago, some young fish of various kinds in the Tweed at Stobo, which were, when in the water, quite undistinguishable from the vegetable matter among which they were taking shelter. It is not an easy matter to paint a fish so as accurately to transmit to canvas its exquisite shape and glowing colours. The moment it is taken from its own element its form alters and its delicate hues fade; and in different localities fish have, like the chameleon, different colours, so that the artist must have a quick eye and a responding hand to catch the rapidly-fleeting tints of the animal. Nothing, for instance, can reveal more beautiful masses of colour than the hauling into the boat of a drift of herring-nets. As breadth after breadth emerges from the water the magnificent ensemble of the fish flashes with ever-changing hues upon the eye—a wondrous pantomimic mixture of glancing blue and gold, and silver and purple, blended into one great burning glow of harmonious colour, lighted into brilliant life by the soft rays of the newly-risen sun. But, alas for the painter! unless he can instantaneously fix the burnished mass on his canvas, the light of its colour will be extinguished, and its beauty be dimmed, long before the boat has reached the harbour. The brightly-coloured fish of the tropics are indeed gorgeous, as is the plumage of tropical birds; but as regards excellence of flavour, beautifully-blended colours, and especially as a food power, they cannot for a moment be compared with that plentiful poor man’s fish—the beautiful common herring of our British waters.

If the breathing apparatus of a fish were to become dry the animal would at once be suffocated. A fish when in the water has very little weight to support, as its specific gravity is about the same as that of the water in which it lives, and the bodies of these animals are so flexible as to aid them in all their movements, while the various fins assist either in balancing the body or in helping it to progress. The motion of a fish is excessively rapid; it can dash along in the water with lightning-like velocity. Many of our sea fish are curiously shaped, such as the hammer-headed shark, the globe-fish, the monkfish, the angel-fish, etc.; then we have the curious forms of the rays, the PluronectidÆ, and of some others that I may call “fancy fish;” but fish of all kinds are admirably adapted to their mode of life and the place where they live—as for instance, in a cave where light has never penetrated there have been found fish without eyes. Fresh-water fish do not, however, vary much in shape, most of them being very elegant. Fish are nearly insensible to pain, and are cold-blooded, their blood being only two degrees warmer than the element in which they swim. It is worthy of being noted also that fish have small brains in comparison to the size of their bodies—considerably smaller in proportion than in the case of the birds or mammalia, but the nerves communicating with the brain are as large in fish, proportionately, as in either the birds or mammalia. So far as personal knowledge goes, I believe the senses of sight and hearing are well developed in most fish, as also those of smell and taste, particularly the sense of smell, which chiefly guides them to their food. We may take for granted, I think, that fish have a very keen sense of smell—more so than most other animals; and thus it is that strong-smelling baits are so successful in fishing. The French people, for instance, when fishing for sprats and sardines, bait the ground with prepared cod-roe, which, by the way, adds very largely to the expense of that branch of fishing in the Bay of Biscay. I may also remind my readers, as an evidence of fish having a strong sense of smell, that salmon-roe used to be a deadly trout-bait, but fishing with salmon-roe is now illegal. It has been said by some naturalists that fish do not hear well, but that assertion is contrary to my own experience; for on making repeated trials as to the sense of hearing in fish, I found them as quick in that faculty as they are sharp in seeing; and have we not all read of pet fish being summoned by means of a bell, and of trouts that have been whistled to their food like dogs? Water is an excellent conductor of sound: it conveys a noise of any kind to a greater distance, and at nearly as great a speed as air. Benjamin Franklin used to experiment on water as a conductor, and soon arrived at the conclusion that its powers in this way were wonderful. By striking two stones together, the experimenter will find that the sound is conveyed to a great distance, and also that it is very loud. Most kinds of fish are voracious feeders, and prey upon each other without the slightest ceremony; and the greatest difficulties of the angler are experienced after the fish have had a good feed, when even the most practised artist, with his most seductive bait, will not induce them to nibble, far less to bite. Many of our fish have a digestion so rapid as only to be comparable to the action of fire, and in good feeding-grounds the growth of a fish usually corresponds to its power of eating. In the sea there exists an admirable field for observing the cannibal propensities of the fish world, where shoals of one species have apparently no other object in life than to chase another kind with a view to eat them; and what goes on in the sea on a wholesale scale is imitated on a smaller scale in the loch and the river. To compensate for the waste of life incidental to their place of birth and their ratio of growth, nature has endowed this class of animals with an enormous power of reproduction. Fish yield their eggs by tens of thousands or millions, according to the danger that has to be incurred in the progress of their growth.

All fish are enormously fecund; indeed there is nothing in the animal world that can in this respect be compared to them, except perhaps a queen bee, which has fifty or sixty thousand young each season; or the white ant, which produces eggs at the rate of fifty per minute, and goes on laying for a period of unknown duration; not to speak of that terrible domestic bugbear which no one likes more particularly to name, but which is popularly supposed to become a great-grandfather in twenty-four hours. The little aphides of the garden may also be noted for their vast fecundity, as may likewise the common house-fly. During a year one green aphis may produce one hundred thousand millions of young; and the house-fly produces twenty millions of eggs in a season!

When I state that the codfish yields its eggs in millions, and that a herring of six or seven ounces in weight is provided with about thirty thousand ova, it will at once be seen that the multiplying power of all kinds of fish is enormous; but then the drain on fish life, consequent on the habitat of these animals, is immense, or at least of corresponding magnitude. Although there may be thirty thousand eggs in a herring, the reader must bear in mind that if these be not vivified by the milt of the male fish, they just rot away in the sea, and never become of any value, except perhaps as food to some minor monster of the deep. Millions upon millions of the eggs that are emitted by the cod or the herring never come to life at all—many of them from the want of the fructifying power, and others from being devoured by enemies. Then, again, of those eggs that are so fortunate as to be ripened, it is pretty certain, I think, from minute and careful inquiry, that fully ninety per cent of the young fish perish before they are six months old. Were only half of the eggs to come to life, and but one moiety of the young fish to live, the sea would so abound with animal life that it would soon be impossible for a boat to move in its waters. But we can never hope to realise such a sight; and when it is considered that a single shoal of herrings consists of millions and millions of individual fish, and takes up a space in the sea far more than that occupied by the parks of London, and yet gives no impediment to navigation, my readers will see the magnitude of our fish supplies; but, from the destruction of fish life by natural causes, the breeding supply is kept down to an amount that cannot, in my opinion, be very far from the point of extermination; and hence I am prepared to argue the urgent necessity of regulation, continued statistical inquiry, and the adoption of fish-culture as an adjunct to the natural supplies.

The figures of fish fecundity are quite reliable, and are not dependent on mere guessing or imagination, because different persons have taken the trouble, the writer amongst others, to count the separate eggs in the roes of some of our fish, in order to ascertain exactly their amount of breeding power. It is well known that the female salmon yields her eggs at the rate of about one thousand for each pound of her weight, and some fresh-water fish are still more prolific; the sea fish, again, far excelling them in reproductive power. The sturgeon, for instance, is wonderfully fecund, as much as two hundred pounds weight of roe having been taken from one of these fish, yielding a total of 7,000,000 of eggs. I have in my possession the results of several investigations into the question of fish fecundity, which were conducted with careful attention to the details, and without any desire to exaggerate: these give the following results:—Codfish, 3,400,000; flounder, 1,250,000; sole, 1,000,000; mackerel, 500,000; herring, 35,000; smelt, 36,000. Mr. Frank Buckland, who some time ago investigated this part of the fish question, quite corroborates such numbers as being correct, having found equally great quantities in fish dissected by himself.

Any of my readers who wish to manipulate these figures may try by way of experiment a few calculations with the herring. The produce of a single herring is, let us say, thirty-six thousand eggs, but we may—and the deduction is a most reasonable one—allow that half of these never come to life, which reduces the quantity born to eighteen thousand. Allowing that the young fish will be able to repeat the story of their birth in three years, we may safely calculate that the breeding stock by various accidents will by that time be reduced to nine thousand individuals; and granting half of these to be females, or let us say, for the sake of rounding the figures, that four thousand of them yield roe, we shall find by multiplying that quantity by thirty-six thousand (the number of eggs in a female herring) that we obtain a total of one hundred and forty-four millions as the produce in three years of a single pair of herrings; and although half of these might be taken as the food of man as soon as they were large enough, there would still be left an immense breeding stock even after all deductions for casualties had been given effect to; so that the devastations committed by man on the shoals while capturing for food uses must be enormous if they affect, as I suppose, the reproductiveness of these useful animals. Of course this is but guess-work, and is merely given as a basis for a more minute statement; but I have conversed with practical people who do not think that, taking all times and seasons into account, even five per cent of the roe of a herring comes to life, far less that such a percentage reaches maturity as table fish.

It is now well enough known, even to the merest tyros in the study of natural history, and to anglers and others interested as well, that the impregnation of fish-eggs is a purely external act; but at one time this was not believed, and even so lately as six years ago a portion of the experiments at the Stormontfield salmon-breeding ponds was dedicated, by Mr. Robert Buist, to a solution of this question, with what result may be easily guessed. The old theory, so stoutly maintained by Mr. Tod Stoddart and others, that it is contrary both to fact and reason that fish can differ from land animals in the matter of the fructification of their eggs, was signally defeated, and the question conclusively settled at the ponds in a very simple way—namely, by placing in the breeding-boxes a quantity of salmon eggs which had not been brought into contact with the milt, and which rotted away; proving emphatically that the sexes do not come into alliance at the time of spawning, and that there is no way of rendering the eggs fruitful unless they are brought into immediate contact with the milt. Curious ideas used to prevail on this branch of natural history. Herodotus observes of the fish of the Nile, that at the season of spawning they move in vast multitudes towards the sea; the males lead the way, and emit the engendering principle in their passage; this the females absorb as they follow, and in consequence conceive, and when their ova are deposited they are consequently matured into fry. LinnÆus backed up this idea, and asserted that there could be no impregnation of the eggs of any animal out of the body, and as fish have no organs of generation, there was in the mind of the great naturalist no more feasible explanation of their mode of reproduction than that given in Beloe’s Herodotus. It is this wonderfully exceptional principle in the life of fish that has given rise to the art of pisciculture—i.e. the artificial impregnation of the eggs of fish forcibly exuded from these animals, which, as will be fully explained in another portion of this work, are brought into contact with the milt, independent altogether of the animal.

The principle of fish life which brings the male and female together at the period of spawning is unknown. It is supposed by some naturalists that fish do not gather into shoals till they are about to perform the grandest action of their nature, and that till that period each animal lives a separate and individual life. If we set down the sense of smell as the power which attracts the fish sexes, we shall be very nearly correct: such cold-blooded animals cannot very well have any more powerful instinct. A very clever Spanish writer on pisciculture hints that the fish have no amatory feeling for each other at that period, thus forming a curious exception to most other animals, and that it is the smell of the roe in the female that attracts the male. As the writer well expresses it—“The curious phenomenon of the fecundation of the eggs or spawn of the female fish away from the bowels of the mothers, and independent of their co-operation in every way, constitutes an interesting exception to the almost universal law of instinct and sympathy in the sexes—a law simple in its essence, as are all nature’s laws, but most prolific in its results; for we see it pass through all the phases of an immense series, from the phenomena of organic attraction shown by the first-named living beings up to the great passions of love and maternity in the human species, forming the affectionate and solid bases of families and the imperishable foundation of society.”

This idea—viz. as to the shoaling of the fish at the period of spawning only—has been prominently thrown out in regard to the herring by parties who do not admit even of a partial migration from the deep to the shallow water, which, however, is an idea that is stoutly held by some writers on the herring question. It is rather interesting, however, in connection with this phase of fish life, to note that particular shoals of herrings deposit their spawn at particular places, that the eggs come simultaneously to life, and that it is quite certain that the young fish remain together for a considerable period—a few months at least—after they are hatched. This is well known from the fact of large bodies of young herrings having been caught during the sprat season; these could not, of course, have been assembled to spawn—they were too young and had no development of milt or roe. This, if these fish separate, gives rise to the question—At what period do the herrings begin their individual wanderings? Sprats, of course—if sprats be sprats and not the young of the herring—may have come together at the period when they are so largely captured for the purpose of perpetuating their kind; but if so, they must live long together before they acquire milt or roe. And how is it that we so often find young herrings in the sprat shoals? Then, again, how comes it that the fishermen do not frequently fall in with the separate herrings during the white-fishing seasons? How is it that fishermen find particular kinds of fish always on particular ground? How is it that eels migrate in immense bodies? My opinion is, that particular kinds of fish do hold always together, or at all events gather at particular seasons into greater or lesser bodies. No doubt, life among the inhabitants of the sea, if we could know it, is quite as diversified as life on land, where we observe that many kinds of animals colonise—ants, bees, etc. Are the old stories about each kind of fish having a king so absolutely incredible after all? That there are schools of fish is certain; how the great bodies may be divided can only be guessed.

Whatever may be the attracting cause, and however powerful the sexual instinct may be among fish, it can scarcely be discussed fully in a work which makes no pretension to being scientific or even technological. It is noteworthy, however, that fish-eggs afford us an admirable opportunity of studying a peculiarly interesting stage of animal life—viz. the embryo stage—which naturally enough is rather obscure in all animals. Having had opportunities of observing the eggs of the salmon in all their stages of progress, from the period of their first contact with the milt till the bursting of the egg and the coming forth of the tiny fish, I will venture briefly to describe what I have seen, because salmon eggs are of a convenient size for continued examination. The roe of this fine fish is, I daresay, pretty familiar to most of my readers. The microscope reveals the eggs of the salmon as being more oval than round, although they appear quite round to the naked eye. A yolk seems to float in the dim-looking mass, and the skin or shell appears full of minute holes, while there is an appearance of a kind of canal or funnel, which opens from the outside and is apparently closed at the inner end. The milt is found to swarm with a species of very small creatures with big heads and long tails, apparently of very low organisation. On the contact of this fluid with the egg, into which it enters by the canal I have described, an immediate change takes place—the ovum, so to speak, becomes illuminated as if by some curious internal power, and the aspect of the egg then appears a great deal brighter and clearer than before; and it is surely wonderful that on the mere touching of the egg with this wonder-working sperm so great a change should take place—a change which indicates that the grand process of reproduction characteristic of all living nature has begun in the ovum, and will go on with increasing strength to maturity.

Beds containing salmon-spawn are so accessible, comparatively speaking, as to render it easy to trace the development of the egg from the embryo to the complete animal. I have personally watched the egg from the date of its contact with the milt till the little salmon has burst out of its fragile prison and waddled away to the shady side of a friendly pebble, evidently anxious to hide its nakedness. I was enabled, in fact, to hatch a few salmon eggs, brought from Stormontfield last Christmas-day, by means of a very simple apparatus in a printing-office, and had therefore an opportunity of daily observation. As may be supposed, however, the transmutation of a salmon egg into a fish is a tedious process, which takes above a hundred days to accomplish. The eggs of the female under the natural system of spawning are laid in the secluded and shallow tributary of some choice stream, in a trough of gravel ploughed up by the fish with great labour, and are there left to be wooed into life by the eternal murmuring of the water. From November till March, through the storms and floods of winter, the ova lie hid among the gravel, slowly but surely quickening into life, and few persons would guess from a mere casual glance at the tributary of a great salmon stream that it held among its bubbling waters such a countless treasure of future fish. A practised person will find out a burrow of salmon eggs with great precision, and a little bit of water may contain perhaps a million of eggs waiting to be summoned into life by the mysterious workings of nature. During the first three weeks from the milting of the egg scarcely any change is discernible in its condition, except that about the end of that period it contains a brilliant spot, which gradually increases in its brilliancy, when certain threads of blood begin faintly to prefigure the anatomy of the young fish. After another day or two, the bright spot seems to assume a ring-like form, having a clear space in the centre, and the blood-threads then become more and more apparent. These blood-like tracings are ultimately seen to take an animal shape; but it would be difficult at first to say what the animal may turn out to be—whether a tadpole or a salmon. After this stage of the development is reached, two bright black specks are then seen—the eyes of the fish. We can now, from day to day, note the form as it gradually assumes a more perfect shape; we can see it change palpably almost from hour to hour. After the egg has been laved by the water for a hundred days, we can observe that the young fish is then thoroughly alive and, to use a common expression, kicking. We can see it moving and can study its anatomy, which, although as yet very rudimentary, contains all the elements of the perfect fish. Heat expedites the birth of the fish. The eggs of a minnow have been sensibly advanced towards maturity by being held on the palm of the hand. The spawn of the lobster has the advantage of being nursed on the tail of the animal till it is just on the point of ripening into life. Salmon eggs deposited early in the season, when the temperature is high, come sooner to life than those spawned in mid-winter: indeed there is a difference of as much as fifty days between those deposited in September and those spawned in December, the one requiring ninety days, the other one hundred and forty days to ripen into life. Salmon have been brought to life in sixty days at Huningue; but the quickest hatching ever accomplished at the Stormontfield breeding-ponds was when the fish came to life in one hundred and twenty days.

I have endeavoured to illustrate these early stages of fish life by a drawing, which shows the eggs at about their natural size, as also the advance of the fish in size and shape.

At the salmon-ponds of Stormontfield the eggs laid down the first season were hatched in one hundred and twenty-eight days, but the eggs of other fish have been known to come to life a great deal sooner. The usual time for the hatching of salmon eggs in our northern rivers is one hundred and thirty days, or between four and five months, according to the openness or severity of the season. When at last the infant animal bursts from the shell, it is a clumsy, unbalanced, tiny thing, having attached to it the remains of the parental egg, which hamper its movements; but after all, the remains of its little prison are exceedingly useful, as for a space of about thirty days the young salmon cannot obtain other nourishment than what is afforded by this umbilical bag.

We cannot, unfortunately, obtain a sight of the ripening eggs of any of our sea fish at a time when they would prove useful to us. No one, so far as I know, has seen the young herring burst from its shell under such advantageous circumstances as we can view the salmon ova; but I have seen the bottled-up spawn of that fish just after it had ripened into life, the infant animal being remarkably like a fragment of cotton thread that had fallen into the water: it moved about with great agility, but required the aid of a microscope to make out that it was a thing endowed with life. Who could suppose, while examining those wavy floating threads, that in a few months afterwards they would be grown into beautiful fish, with a mechanism of bones to bind their flesh together, scales to protect their body, and fins to guide them in the water? But young herring cannot be long bottled up for observation, or be kept in an artificial atmosphere; for in that condition they die almost before there is time to see them live; and when in the sea there are no means of tracing them, because they are speedily lost in an immensity of water.

There are points of contrast between the salmon and the herring which I cannot pass without notice. They form the St. Giles’ and St. James’ of the fish world, the one being a portion of the rich man’s food, and the other filling the poor man’s dish. The salmon is hedged round by protecting Acts of Parliament, but the herring gets leave to grow just as it swims, parliamentary statutes being thought unnecessary for its protection. The salmon is born in its fine nursery, and is wakened into life by the music of beautiful streams: it has nurses and night-watchers, who hover over its cradle and guide its infant ways; but the herring, like the brat of some wandering pauper, is dropped in the great ocean workhouse, and cradled amid the hoarse roar of the ravening waters; and whether it lives or dies is a matter of no moment, and no one’s business. Herring mortality in its infantile stages is appalling, and even in its old age, at a time when the rich man’s fish is protected from the greed of its enemies, the herring is doomed to suffer the most. And then, to finish up with the same appropriateness as they have lived, the venison of the waters is daintily laid out on a slab of marble, while the vulgar but beautiful herring is handled by a dirty costermonger, who hurls it about in a filthy cart drawn by a wretched donkey. At the hour of reproduction the salmon is guarded with jealous care from the hand of man, whilst at the same season the herring is offered up a wholesale sacrifice to the destroyer. It is only at its period of spawning that the herring is fished. How comes it to pass that what is a highly punishable crime in the one instance is a government-rewarded merit in the other? To kill a gravid salmon is as nearly as possible felony; but to kill a herring as it rests on the spawning-bed is an act at once meritorious and profitable!

Having given my readers a general idea of the fecundity of fish, and the method of fructifying the eggs, and of the development of these into fish—for, of course, the process will be nearly the same with all kinds of fish eggs, the only difference perhaps being that the eggs of some varieties will take a longer time to hatch than the eggs of others—I will now pass on to consider the question of fish growth.

All fish are not oviparous. There is a well-known blenny which is viviparous, the young of which at the time of their birth are so perfect as to be able to swim about with great ease; and this fish is also very productive. Our skate fishes (RaiÆ) are all viviparous. “The young are enclosed in a horny capsule of an oblong square shape, with a filament at each corner. It is nourished by means of an umbilical bag till the due period of exclusion arrives, when it enters upon an independent existence.” I could name a few other fish which are viviparous. In the fish-room of the British Museum may be seen one of these. It is known as Ditrema argentea, and is plentifully found in the seas of South America. But our information on this portion of the natural history of fish is very obscure at present.

There are many facts of fish biography that have yet to be ascertained, and which, if we knew them, would probably conduce to a stricter economy of fish life and the better regulation of the fisheries. Beyond a knowledge of mere generalities, the animal kingdom of the sea is a sealed book. No person can tell, for example, how long a time elapses from the birth of any particular sea fish till the period when it is brought to table. Sea fish grow up unheeded—quite, in a sense, out of the bounds of observation. Naturalists can only guess at what rate a codfish grows. Even the life of a herring, in its most important phase, is still a mystery; and at what age the mackerel or any other fish becomes reproductive, who can say? The salmon is the one particular fish that has as yet been compelled to render up to those inquiring the secret of its birth and the ratio of its growth. (See Natural and Economic History of the Salmon.) We have imprisoned this valuable fish in artificial ponds, and by robbing it of its eggs have noted when the young ones were born and how they grew. It would be equally easy to devise a means of observing sea fish. Why should we not erect a great marine observatory, where we could, as in the case of the Stormontfield-bred salmon, watch the young fish burst from its shell, and for a year or two observe and study the progress of the animal, and ascertain its rate of growth, and especially the period at which it becomes reproductive? The government might act upon this suggestion, and vote a few thousand pounds annually for the support of a series of marine fish-ponds; for something more is required than the resources of an amateur naturalist to determine how fish live and grow.

What naturalists chiefly and greatly need in respect of our sea fish is, precise information as to their rate of growth. We have a personal knowledge of the fact of the sea fish selecting our shores as a spawning-ground, but we do not precisely know in some instances the exact time of spawning, how long the spawn takes to quicken into life, or at what rate the fish increase in growth.

The eel may be taken as an example of our ignorance of fish life. Do our professed naturalists know anything about it beyond its migratory habits?—habits which, from sheer ignorance, have at one period or another been guessed as pertaining to all kinds of fish. The tendency to the romantic, specially exhibited in the amount of travelling power bestowed by the elder naturalists on this class of animals, would seem to be very difficult to put down.

About two years ago an old story about the eel was gravely revived by having the larger portion of a little book devoted to its elucidation—an old story seriously informing us that the silver eel is the product of a black beetle. But no one need wonder at a new story about the eel, far less at the revival of this old one; for the eel is a fish that has at all times experienced the greatest difficulty in obtaining recognition as being anything at all in the animal world, or as having respectable parentage of even the humblest kind. In fact, the study of the natural history of the eel has been hampered by old-world romances and quaint fancies about its birth, or, in its case, may I not say invention? “The eel is born of the mud,” said one old author. “It grows out of hairs,” said another. “It is the creation of the dews of evening,” exclaimed a third. “Nonsense,” emphatically uttered a fourth controversialist, “it is produced by means of electricity.” “You are all wrong,” sserted a fifth, “the eel is generated from turf;” and a sixth theorist, determined to outdo all the others and come nearer the mark than any of his predecessors, assures the public that the young fish are grown from particles scraped off the old ones! The beetle theorist tells us that the silver eel is a neuter, having neither milt nor roe, and is therefore quite incapable of perpetuating its kind; and, in short, that it is a romance of nature, being one of the productions of some wondrous lepidopterous animals seen by Mr. Cairncross (the author of the work alluded to) about the place where he lived in Forfarshire, its other production being of its own kind, a black beetle! The story of the rapid growth and transformation of the salmon is—as will by and by be seen—wonderful enough in its way, but it is certainly far surpassed by the extraordinary silver eel, which is at one and the same time a fish and an insect.

There can be no doubt that the eel is a curious enough animal even without the extra attributes bestowed upon it by this very original naturalist, for that fish is in many respects the opposite of the salmon: it is spawned in the sea, and almost immediately after coming to life proceeds to live in brackish or entirely fresh water. It is another of the curious features of fish life that about the period when eels are on their way to the sea, where they find a suitable spawning-ground, salmon are on their way from the sea up to the river-heads to fulfil the grand instinct of their nature—namely, reproduction. The periodical migrations of the eel, on which instinct has been founded the great fishing industry of Comacchio, on the Adriatic, described in another portion of this volume, can be observed in all parts of the globe, and they take place, according to the climate, at different periods from February to May; the fish frequenting such canals or rivers as have communication with the sea. The myriads of young eels which ascend are almost beyond belief; they are in numbers sufficient for the population of all the waters of the globe—that is, if there were protective laws to shield them from destruction, or reservoirs in which they might be preserved to be used for food as required. The eel, indeed, is quite as prolific as the generality of sea fish. As a corroboration of the prolificness of the animal, it may be stated that eels have been noted—but that was some years ago—to pass up the river Thames from the sea at the extraordinary rate of eighteen hundred per minute! This montee was called eel-fair.

It is clear from certain facts in the history of this peculiar animal that, like all other fish, it can suit its life and growth to whatever circumstances it may be placed in, and seems to be quite able to multiply and replenish its species in rivers and lakes as well as in the sea. In Scotland eels are very seldom eaten, a strong prejudice existing in that country against the fish on account of its serpentine shape; but for all that the eel is a nutritious and palatable fish, and is highly susceptible of the arts of the cook. At one time the eel was thought to be viviparous, but naturalists now know better, having found out that eels produce their young in the same way as most other fish do.

It would be interesting, and profitable as well, to know as much of any one of our sea fish as we now know of the salmon, but so little progress is being made in observing the natural history of fish that we cannot expect for some time to know much more than we do at present; everything in the fish world seems so much to be taken for granted that we are still inclined rather to revive the old traditions than to study or search out new facts. Naturalists are so ignorant of how the work of growth is carried on in the fish world—in fact, it is so difficult to investigate points of natural history in the depths of the sea—that we cannot wonder at less being known about marine animals than about any other class of living beings.

It is the want of precise information about the growth of the fish that has of late been telling heavily against our fisheries, for in the meantime all is fish that comes to the fisherman’s net, no matter of what size the animals may be, or whether or not they have been allowed time to perpetuate their kind. No person, either naturalist or fisherman, knows how long a period elapses from the date of its birth before a turbot or codfish becomes reproductive. It is now well known, in consequence of the repeated experiments made with that fish, that the salmon grows with immense rapidity, a consequence in some degree of its quick digestive power. The codfish, again—and I reason from the analogy of its greatly slower power of digesting its food and from other corroborative circumstances—must be correspondingly slow in its growth; but people must not, in consequence of this slow power of digestion, believe all they hear about the miscellaneous articles often said to be found in the stomach of a codfish, as a large number of the curiosities found in the intestinal regions of his codship are often placed there by fishermen, either by way of joke or in order to increase the weight and so enhance the price of the animal.

As regards the natural history of one of our best-known food fishes, I have taken the pains to compile a brief precis of its life from the best account of it that is known, keeping in the background at present any knowledge or speculation of my own regarding it. I allude to the mackerel; and the following facts are from an evidently well-studied chapter of Mr. Jonathan Couch’s Fishes of the British Islands, by which it will be at once seen that our knowledge of the growing power of this well-known fish is very defective.

1. Mackerel, geographically speaking, are distributed over a wide expanse of water, embracing the whole of the European coasts, as well as the coasts of North America, and this fish may be caught as far southward as the Canary Islands. 2. The mackerel is a wandering unsteady fish, supposed to be migratory, but individuals are always found in the British seas. 3. This fish appears off the British coasts in quantity early in the year; that is, in January and February. 4. The male kind are supposed to be more numerous than the female. 5. The early appearance of this fish is not dependent on the weather. 6. The mackerel, like the herring, was at one time supposed to be a native of foreign seas. 7. This fish is laden with spawn in May, and it has been known to deposit its eggs upon our shores in the following month.

Such is a brief resumÉ of Mr. Couch’s chapter on the mackerel.

Now, we have no account here of how long it is ere the spawn of the mackerel quickens into life, or at what age that fish becomes reproductive, although in these two points is unquestionably obtained the key-note to the natural history of all fishes, whether they be salmon or sprats. In fact—and it is no particular demerit of Mr. Couch more than of every other naturalist—we have no precise information whatever on this point of growth power. We have at best only a few guesses and general deductions, and we would like to know as regards all fish—1st, When they spawn; 2d, How long it is ere the spawn quickens into life; and 3d, At what period the young fish will be able to repeat the story of their birth. These points once known—and they are most essential to the proper understanding of the economy of our fisheries—the chief remaining questions connected with fishing industry would be of comparatively easy solution, and admit of our regulating the power of capture to the natural conditions of supply.

As another example of our ignorance of fish life, I may instance that diminutive member of the Clupea family—the whitebait. This fish, which is so much better known gastronomically than it is scientifically, was thought at one time to be found only in the Thames, but it is much more generally diffused than is supposed. It is found for certain, and in great plenty, in three rivers—viz., the Thames, the Forth, and the Hamble. I have also seen it taken out of the Humber, not far from Hull, and have heard of its being caught near the mouth of the Deveron, on the Moray Firth; and likewise of its being found in plentiful quantities off the Isle of Wight. Mr. Stewart, the natural history draughtsman, tells me also that he has seen it taken in bushels on many parts of the Clyde, and that at certain seasons, while engaged in taking coal-fish, he has found them so stuffed with whitebait that by holding the large fish by the tail the little silvery whitebait have fallen out in handfuls. The whitebait has become celebrated from the mode in which it is cooked, and the excuse it affords to Londoners for an afternoon’s excursion, as also from its forming a famous dish at the annual fish-dinner of her Majesty’s ministers; but truth compels me to state that there is nothing in whitebait beyond its susceptibility of taking on a flavour from the skill of the cook. It is poor feeding when compared to a dish of sprats, or (an illegal) fry of young salmon; and it has been said in joke that an expert cook can make up capital whitebait by means of flour and oil! But to eat whitebait is a fashion of the season, and the well-served tables of the Greenwich and Blackwall taverns, with their pleasant outlook to the river, and their inducements of chablis and other choice wines and comestibles, are undoubtedly very attractive, whether the persons partaking of these dainties be ministers of state or merchants’ clerks.

The whitebait, however, if I cannot honestly praise it as a table fish, is particularly interesting as an object of natural history, there having been from time to time, as in the case of most other fish, some very learned disputes as to where it comes from, how it grows, and whether or not it be a distinct member of the herring family or the young of some other fish. The whitebait—which, although found in rivers, is strictly speaking a sea fish—is a tiny animal, varying in length, when taken for cooking purposes, from two to four inches, and has never been seen of a greater length than five inches. In appearance it is pale and silvery, with a greenish back, and ought to be cooked immediately after being caught; indeed if, like Lord Lovat’s salmon, whitebait could leap out of the water into the frying-pan, it would be a decided advantage to those dining upon it, for if kept even for a few hours it becomes greatly deteriorated, and, as a consequence, requires all the more cooking to bring the flavour up to the proper pitch of gastronomic excellence. In fact, it is necessary to keep the fish alive in a tub of water, and to ladle them out for the process of cooking as the guests may arrive. Perhaps, as all fish are chameleon-like in reflecting not only the colour of their abode, but what they feed on as well, the supposed fine flavour of whitebait, so far as it is not conferred upon that fish by the cook, may arise from the matters held in solution in the Thames water, and so the result from the corrupt source of the supply may be a quicker than ordinary decay. The waters of the Forth at the whitebait ground, of which I have given a slight sketch, are clean and clear, a little way above Inchgarvie, where the sprat-fishing is usually carried on, and the whitebait taken there are in consequence slightly different in colour, and greatly so in taste, from those obtained in the Thames; in fact, all kinds of fish, including salmon, are able to live and thrive in the Firth of Forth. It is long since the refined salmon forsook the Thames, but then salmon are very delicate in their eating, and at once take on the surrounding flavour, whatever that may be. Creditable attempts are now being made to re-stock the Thames, especially the upper waters, with more valuable fish than are at present contained in that river, but whether these attempts will be successful yet remains to be seen. I have been watching with great interest what is being done by Mr. Frank Buckland and others; but salmon I fear cannot at present live in the Thames. To thrive successfully, that fish must have access to the sea, and how a salmon can ever penetrate to the salt water with the river in its present state is a problem that must be left for future solution; however, as Mr. Frank Buckland very truthfully remarks, if the salmon are not first sent down the Thames they cannot be expected ever to come up that noble river.

Returning, however, to our whitebait, it may be stated that that fish was once thought to be the young of the shad, which is itself an interesting fish, coming from the sea to deposit its spawn in the fresh waters. The shad was at one time thought to be the patriarch of the herring tribe; and it was said, in the days when the old theory about the migration of the herring was believed in, that the great shoals which came to this country from the icy seas of the high latitudes were led on their wonderful tour by a few thousands of this gigantic fish. Pennant conjectured that whitebait was an independent species, but so difficult is it to investigate such facts in the water that it was not till many years had elapsed that the question was set at rest so far as to determine at any rate that whitebait were not the young of either the Alice or the Twaite shad, which, by the by, is a coarse and insipid fish—

Some investigations I have in hand may settle the question whether or not the whitebait be herring-fry or a distinct fish. As yet I have never at any season of the year found an example of whitebait containing either milt or roe, although it is said that examples may be taken full of both during the early winter months. This, of course, is not conclusive evidence of its being the young of some other fish, although it would go some length in proving it a distinct species; but I need not enter further into the controversy at present, as it is not of much interest to the general reader, except to say that whitebait, whatever species it may belong to, comes up from the sea, where it has been spawned, to feed in the river. I may mention that this fish cannot now be taken so far up the river Thames as formerly. Whitebait are now usually caught between Gravesend and Woolwich, and the fish are in their best season between April and September. It is not unusual for sea fish to ascend our rivers: the eel, as I have already narrated, spawns in the sea, and the young of that fish ascend to the fresh water, in which they live till they are seized with the migratory instinct. The parentage of the whitebait will be discovered in the sea, and the changes undergone by fish during their growth are so varied and curious that it would be difficult to predict what the little whitebait may turn out to be—whiting perhaps! After being told that the silver eel is the produce of a black beetle, and knowing that a tadpole is an infantile frog, and that the zoea ultimately becomes a crab, we need not wonder if we are some day told that whitebait becomes in time metamorphosed into some other entirely different fish!

Besides whitebait there are other mysterious fish—especially in Scotland—which are well worthy of being alluded to. An idea prevails in Scotland that the vendace of Lochmaben and the powan of Lochlomond are really herrings forced into fresh water, and slightly altered by the circumstances of a new dwelling-place, change of food, and other causes. One learned person lately ascribed the presence of sea fish in fresh water to the great wave which had at one time passed over the country. But no doubt the real cause is that these peculiar fish were brought to those lakes ages ago by monks or other persons who were adepts in the piscicultural art.

A brief summary of the chief points in the habits of these mysterious fish may interest the reader. The “vendiss,” as it is locally called, occurs nowhere but in the waters at Lochmaben, in Dumfriesshire; and it is thought by the general run of the country people to be, like the powan of Lochlomond, a fresh-water herring. The history of this fish is quite unknown, but it is thought to have been introduced into the Castle Loch of Lochmaben in the early monkish times, when it was essential, for the proper observance of church fasts, to have an ample supply of fish for fast-day fare. It is curious as regards the vendace that they float about in shoals, that they make the same kind of poppling noise as the herring, and that they cannot be easily taken by any kind of bait. At certain seasons of the year the people assemble for the purpose of holding a vendace feast, at which times large quantities of the fish are caught by means of a sweep net. The fish is said to have been found in other waters besides those of Lochmaben, but I have never been able to see a specimen anywhere else. There are a great number of traditions afloat about the vendace, and a story of its having been introduced to the lake by Mary Queen of Scots. The country people are very proud of their fish, and take a pride in showing it to strangers. The principal information I can give about the vendace, without becoming technical, is, that it is a beautiful and very symmetrical fish, about seven or eight inches long, not at all unlike a herring, only not so brilliant in the colour; and that the females of the vendace seem to be about a third more numerous than the males—a characteristic which is also observed in the salmon family. The vendace spawn about the beginning of winter, and for this purpose gather, like the herring, into shoals. They are very productive, and do not take long to grow to maturity.

The peculiarities of the Lochleven trout may be chiefly ascribed to a peculiar feeding-ground. Having lived at one time on the banks of this far-famed loch, I had ample time and many opportunities of studying the habits and anatomy, as well as the fine flavour, of this beautiful fish, which, in my humble opinion, has no equal in any other waters. Feeding I believe to be everything, whether the subjects operated upon be cattle, capons, or carps. The land-locked bays of Scotland afford richer flavoured fish than the wider expanses of water, where the finny tribe, it may be, are much more numerous, but have not the same quantity or variety of food, and, as a consequence, the fish obtained in such places are comparatively poor both in size and flavour. Nothing can be more certain than that a given expanse of water will feed only a certain number of fish; if there be more than the feeding-ground will support they will be small in size, and if the fish again be very large it may be taken for granted that the water could easily support a few more. It is well known, for instance, that the superiority of the herrings caught in the inland sea-lochs of Scotland is owing to the fish finding there a better feeding-ground than in the large and exposed open bays. Look, for instance, at Lochfyne: the land runs down to the water’s edge, and the surface water or drainage carries with it rich food to fatten the loch, and put flesh on the herring; and what fish is finer, I would ask, than a Lochfyne herring? Again, in the bay of Wick, which is the scene of the largest herring fishery in the world, the fish have no land food, being shut out from such a luxury by a vast sea wall of everlasting rock; and the consequence is, that the Wick herrings are not nearly so rich in flavour as those taken in the sea-lochs of the west of Scotland. In the same way I account for the rich flavour and beautiful colour of the trout of Lochleven. This fish has been acclimatised with more or less success in other waters, but when transplanted it deteriorates in flavour, and gradually loses its beautiful colour—another proof that much depends on the feeding-ground; indeed, the fact of the trout having deteriorated in quality as a consequence of the abridgment of their feeding-range, is on this point quite conclusive. I feel certain, however, that there must be more than one kind of these Lochleven trouts; there is, at any rate, one curious fact in their life worth noting, and that is, that they are often in prime condition for table use when other trouts are spawning.

The powan, another of the mysterious fish of Scotland, is also considered to be a fresh-water herring, and thought to be confined exclusively to Lochlomond, where they are taken in great quantities. It is supposed by persons versed in the subject that it is possible to acclimatise sea fish in fresh water, and that the vendace and powan, changed by the circumstances in which they have been placed, are, or were, undoubtedly herrings. The fish in Lochlomond also gather into shoals, and on looking at a few of them one is irresistibly forced to the conclusion, that in size and shape they are remarkably like the common herring. The powan of Lochlomond and the pollan of Lough Neagh are not the same fish, but both belong to the Coregoni: the powan is long and slender, while the pollan is an altogether stouter fish, although well shaped and beautifully proportioned.

I could analyse the natural history of many other fish, but the result in all cases is nearly the same, and ends in a repeated expression that what we require as regards all fish is the date of their period of reproduction; all other information without this great fact is comparatively unimportant. It is difficult, however, to obtain any reliable information on the natural history of fish either by way of inquiry or by means of experiments. Naturalists cannot live in the water, and those who live on it, and have opportunities for observation, have not the necessary ability to record, or at any rate to generalise what they see. No two fishermen, for instance, will agree on any one point regarding the animals of the deep. I have examined every intelligent fisherman I have met within the last ten years, numbering above one hundred, and few of them have any real knowledge regarding the habits of the fish which it is their business to capture. As an instance of fishermen’s knowledge, one of that body recently repeated to me the old story of the migration of the herring, holding that the herring comes from Iceland to spawn, and that the sprat goes to the same icy region in order that it may fulfil the same instinct.

“Where are the haddocks?” I once asked a Newhaven fisherman. “They are about all eaten up, sir,” was his very innocent reply; and I believe this to be true. The shore races of that fish have long disappeared, and our fishermen have now to seek this most palatable inhabitant of the sea afar off in the deep waters. Vast numbers of the haddock used to be taken in the Firth of Forth, but during late years they have become very scarce, and the boats now require to go a night’s voyage to seek for them. If we knew the minutiÆ of the life of this fish, we should be better able to regulate the season for its capture, and the percentage that we might with safety take from the water without deteriorating the breeding power of the animal. There are some touches of romance even about the haddock, but I need not further allude to these in this division of my book, as I shall have to refer to it again under the head of the “White Fish Fisheries.” It is, like all fish, wonderfully prolific, and is looked upon by the fishermen as being also a migratory fish, as are also the turbot and many other sea animals.

The family to which the haddock belongs embraces many of our best food fish, as whiting, cod, ling, etc.; but of the growth and habits of the members of this family we are as ignorant as we are of the natural history of the whitebait or sprat. I have the authority of a rather learned Buckie fisherman (recently drowned, poor fellow! in the great storm on the Moray Frith) for stating that codfish do not grow at a greater rate than from eight to twelve ounces per annum. This fisherman had seen a cod that had got enclosed by some accident in a large rock pool, and so had obtained for a few weeks the advantage of studying its powers of digestion, which he found to be particularly slow, although there was abundant food. The haddock, which is a far more active fish, my informant considered to grow at a more rapid rate. On asking this man about the food of fishes, he said he was of opinion that they preyed extensively upon each other, but that, so far as his opportunities of observation went, they did not as a matter of course live upon each other’s spawn; in other words, he did not think that the enormous quantities of roe and milt given to fish were provided, as has been supposed by one or two writers on the subject, for any other purpose than the keeping up of the species. The spawn of all kinds of fish is extensively wasted by other means; and these animals have no doubt a thousand ways of obtaining food that are yet unknown to man; indeed, the very element in which they live is in a sense a great mass of living matter, and it doubtless affords by means of minute animals a wonderful source of supply. Fish, too, are less dainty in their food than is generally supposed, and some kinds eat garbage of the most revolting description with great avidity.

I take this opportunity of correcting the very common error that all fish are migratory. Some fishermen, and naturalists as well, picture the haddock and the herring as being afflicted with perpetual motion—as being wanderers from sea to sea and shore to shore. The migratory instinct in fish is, in my opinion, very limited. They do move about a little, without doubt, but not further than from their feeding-ground to their spawning-ground—from deep to shallow water. Some plan of taking fish other than the present must speedily be devised; for now we only capture them—and I take the herring as an example—over their spawning-ground, when, according to all good authority, they must be in their worst possible condition, their whole flesh-forming or fattening power having been bestowed on the formation of the milt and roe. I repudiate altogether this iteration of the periodical wandering instincts of the finny tribes. There are great fish colonies in the sea, in the same way as there are great seats of population on land, and these fish colonies are stationary, having, comparatively speaking, but a limited range of water in which to live and die. Adventurous individuals of the fish world occasionally roam far away from home, and speedily find themselves in a warmer or colder climate, as the case may be; but, speaking generally, as the salmon returns to its own waters, so do sea fish keep to their own colony.

Our larger shoals of fish, which form money-yielding industries, are of wonderful extent, and must have been gathering and increasing for ages, having a population multiplied almost beyond belief. Century after century must have passed away as these colonies grew in size, and were subjected to all kinds of influences, evil or good: at times decimated by enemies, or perhaps attacked by mysterious diseases, that killed the fish in tens of thousands. At Rockall, for instance, there was lately discovered a cod depÔt, about which a kind of sensation was made—perhaps by interested parties—in the public prints, but the supply obtained at that place was only of brief duration. This fish colony, which had evidently fixed upon a good food-giving centre, was too infantile to be able to stand the heavy draughts that were all at once made upon it. Schools or shoals of fish, when they are of such an extent as will admit of constant fishing, must have been forming during long periods of time; for we know that, despite the wonderful fecundity of all kinds of sea fish, the expenditure of both seed and life is something tremendous. We may rest assured that, if a female codfish yields its roe by millions, a balancing-power exists in the water that prevents the bulk of them from coming to life, or at any rate from reaching maturity. If it were not so, how came it, in the days when there was no fish commerce, and when man only killed the denizens of the sea for the supply of his individual wants, that our waters were not, so to speak, impassable from a superfluity of fish? Buffon has said that if a pair of herrings were left to breed and multiply undisturbed for a period of twenty years, they would yield a fish bulk equal to the whole of the globe in which we live!

The subject of fish growth—particularly as regards the changes undergone by the salmon family—will be found further elucidated under the head of “Fish Culture,” and incidentally in some other divisions of this work.