THE ARTIFICIAL PRODUCTION OF FISH. [This is a pamphlet of 22 pages which has reached several editions in London.] at length she is obliged to relieve herself of their weight and volume. This she does by pressing her belly against pebbles, or any other hard substance at the bottom of the water. The eggs flow from her by the anus. She previously prepares a sort of hole to receive them. THE object of this pamphlet is to make known the means by which fish of all descriptions may be multipled in rivers to an almost Then comes the male, and by a like presincalculable extent. The principle employed sure he releaves himself of the milt, which is not new in theory; but it is only within the flows also from the anus on to the eggs, and last few years that any practical application fecundates them. The fish afterwards cover of it on an extensive scale has taken place. up the eggs with sand or pebbles, or leave This application has been made in France, them, and in due time the eggs become trans and with success so complete and extraordi- formed into fish. nary as to be almost incredible. Our hope is II. The quantity of eggs which the female that it will be adopted on a grand scale in this fish of all sorts deposit is very considerable; country also. In Great Britain and Ireland of some it is truly prodigious. The carp, for there are rivers and streams, lakes and canals, example, produces about a quarter of a milinnumerable; and they may be made to yield lion at a time; the perch a great many more; annually millions on millions of fish: we say the trout seven or eight hundred; the salmon millions, and say it on good authority. several hundred; the sturgeon between six It has been remarked, that the man who and seven millions; and the pike a vast nummakes two blades of corn grow where only one grew before is a benefactor of humanity. If this be true, and true it is, we respectfully submit that our tiny volume is worthy of the attention of the legislator, the country gentleman, and the clergyman,-for it shows how an immense addition may be made to the people's food with scarcely any expense. To persons engaged in the fishing trade in rivers, and to professed anglers, it will, we conceive, recommend itself. I. The manner in which most fish propagate their species is of course well known to all readers. "No sooner," in the words of a most distinguished naturalist, "does the sun of spring begin to spread its vivifying warmth, and no sooner does its renovating and irresistible influence penetrate to the depths of the waters," than a peculiar organ develops and increases in male fish. This organ, which is double, and which extends itself in the superior part of the abdomen, almost equalling it in length, has received the name of milt. The milt is the seminal or fecundating liquor. It grows gradually during several months; and then softens, or so to speak, melts or ripens, as spawning time approaches. When discharged from the fish it is of a milky color. When the milt begins to form in the male, the ovaries of the female begin to fill with eggs, which, however, are almost imperceptible. These organs are two in number in the greater part of fish, but only one in the others. Confined in a membrane, they occupy in the abdomen a place analogous to that which the milt occupies in males, and are nearly equal to it in length. The eggs they contain increase in proportion as the milt becomes tumefied. As the eggs grow they cause pain and become very burdensome to the female; until ber. A very small portion of milt suffices to give life to a large quantity of eggs. It would therefore appear that nothing in the world ought to be more abundant than fish of all descriptions. But only a very small portion indeed of the eggs come to maturity; some naturalists calculate that not one in a hundred do so. Of the rest no inconsiderable portion are devoured by other fish. The males of some species, and indeed the females too, also eat their own eggs; and a great quantity are destroyed by getting mixed with mud and dirt. III. It certainly seems strange that man, who has done so many wonderful things,who has, so to speak, scaled the heavens, to learn the movements of suns and planets,— who has plunged deep into the earth for mineral treasures,-who has turned many a mournful morass, and dreary forest, and barren waste, into fruitful corn-fields or abundant pasturages, who has made the tremendous agent, electricity itself, docile to his will,-it is strange that he, with his vast ingenuity, should never have bethought him of taking measures for preserving the eggs of fish, and thereby secure to himself, in all climates and at all seasons, an abundant supply of wholesome food. Still stranger perhaps is it to find, that though he has taken immense pains to discover the secrets of nature, even in matters of mere scientific, or, if we may so say, idle curiosity, centuries passed away before it occurred to him that he might do with fish what he has done for animals, and birds, and plants,— assist and control, and improve, the operations of nature; that is to say, that, instead of leaving the female to deposit her eggs and the male his milt, and then abandon them, he might cause the female to discharge her bur den, and the male his fecundating liquor, female. In Italy, Spallanzani successfully ex where he pleased; that he might assist them perimented in a similar manner on the spawn in the operation; and that for so doing he of toads, and of certain descriptions of fish. might obtain a living fish from almost every At a later period experiments were made with egg. success on the eggs of salmon in Scotland by Dr. Knox, Mr. Shaw, and one or two others. And here in England the same sort of thing has been done. But the strangest thing of all undoubtedly is, that when he did learn that he could produce fish as well as the fish themselves-when scientific naturalists discovered that by casting some of the male's milt on the female's eggs fish would be brought forth, as surely as if the operation had been done by the parents in the bed of a river-it never struck him that herein was the means of increasing, a million and a million fold, the production of his lakes and rivers and streams, and reservoirs and ponds of making, in a word, the waters as fruitful, in their way, as the land is of corn and grain. The ancient Greeks and Romans, who paid extraordinary attention to the breeding of fish, may, to be sure, have known something of all this; but if they did, their knowledge did not descend to us, and is therefore to us as though it had never existed. As to the means of protecting the eggs of fish from the accidents of the waters, or the voracity of its occupants, none of incontestable efficiency are described in books or known in practice; and the proof of this is, that in France and Germany, England and Scotland, and indeed in every part of Europe, there have of late years been general complaints of the gradual yet rapid decline in the supply of various sorts of fish, not only in rivers, but on the coasts.* But as we have already intimated, it never entered the mind of any of these great savans -nor of their successors-nor of the tens of thousands of persons, who, in different countries, have made the natural history of fish a subject of study-that this way of breeding fish was something more than a simple scientific experiment, curious but useless,-that it was of practical and commercial, political and social importance, inasmuch as it might be made a new branch of commerce, which would add greatly to the national wealth, give employment to thousands, create an inexhaustible supply of cheap, nourishing, and wholesome provisions for all classes of the people-and be, in short, to rivers and waters what agricul ture is to land. For this glorious but singularly simple idea, the world is indebted to two humble fishermen, named Gehin and Remy, of an obscure village called La Bresse, in the department of the Vosges, in France. IV. The department of the Vosges is traversed by the Moselle, possesses many of the tributaries of that beautiful river, together with several streams and some lakes. The fine clear waters of all these, made them the most famous resort of trout in all France; and the production of that fish was so considerable that it formed a large portion of the food of the population. With respect to what we call the artificial production of fish-i. e. the taking by man of the female's eggs, and the fecundation of them by means of the male's milt, applied by him- Several years ago, however, the yield was the first idea of it was conceived no further observed to decline, and it continued year back than in 1758. It is, we believe, to Count after year to diminish. Messrs. Gehin and Von Golstein, a German naturalist, that the Remy made it their business to attempt to dis scientific world is indebted for this grand con- cover if any, and if so, what means could be ception; as also for the first experiments which devised for checking the evil. After studying proved its truth. Having taken a female trout night and day for a long time the habits of the about to spawn, he pressed out her eggs, and trout, they came to the conclusion that it would then pressed on to them the milt of a male. Af be easy to preserve the eggs and to fecundate ter a certain number of days, he had the sat-them by the aid of the milt of the male. isfaction of seeing young fish produced, which Having watched the proceedings of the male grew and flourished. Another German nat- and female at spawning time (it is in the month uralist, Jacobi by name, made, a few years of November in the Vosges), they soon saw later, a similar experiment with a like result; and, going a step further, he actually caused the milt to breed fish from the eggs of a dead how they were to act. Their first experiment cent departments. In the course of a short | being first to stock with fish, by their system, time, they succeeded in stocking these waters such rivers as should be pointed to them, and with millions of trout. It is to be observed, that although the fecundation of the eggs of fish by the means employed by Gehin and Remy was, as we have seen, known to scientific ichthyologists, it was perfectly unknown to them. These poor men had never heard of Golstein or Jacobi, of Lacépède or Sannoni; they had probably never in their lives opened a book on the natural history of fish; consequently it was by their own unaided intelligence and patient investigation that they arrived at the discovery of the "great fact:" and surely the same credit is due to them, for it is as if it had been quite original. Though they came atter Golstein, they rank as high-nay higher, for they had none of his instruction or means of observation. this case. Though bad news proverbially flies fast, information really useful to the public not unfrequently travels very slowly. It was so in Until the beginning of 1849, nothing was heard of the discovery and its great results beyond the department of the Vosges and its immediate vicinity; and perhaps nothing would have been heard of it until this day, if an eminent and learned physician residing in the department, who had taken much interest in the matter, had not called attention to it. For thus taking the light from under the bushel, a very deep debt of gratitude is due to him, not only from his own countrymen, but from foreign nations. next to teach that system to the peasantry. They were treated, too, as men who have made a great scientific discovery, and secured an immense benefit to their country. Many savans vied with each other in doing them honor; the President of the Republic and his ministers made them dine at their tables and figure at their receptions. A Commission, consisting of distinguished scientific men, was appointed to superintend their operations. V. We now proceed to describe Gehin and Remy's plan as applied to trout. No great space will be required to do so; for, like most things that are really useful, it is of remarkable simplicity. For the sake of convenience we put it into the shape of rules: - 1. Prepare a vessel containing about a quart of pure fresh water. 2. Take the female at the moment at which she is about to spawn. Hold her by the back with the left hand, with her head and body near you. If she tries to escape, pass the hand gently to and fro on her belly this soothes her; if, however, she continues restless, get some one to hold her by the tail. : 3. When she is tranquil, place her over the vessel containing the water, and with the thumb and finger of the right hand press gently on her belly downwards, towards the tail. This pressure should be done in the same way as one would draw one's thumb and finger down a finger, or it may be compared to the This gentleman, Doctor Haxo of Epinal, milking of a cow; but care must be taken that perpetual Secretary of the Société d'Emula- it be not too heavy. tion, and member of the Conseil Académique 4. The eggs, under the pressure, will immeof the Department of the Vosges, addressed, diately spurt forth into the water. If they do in the month of March, 1849, an admirably not come easily, it is a proof that they are not written communication to the Academy of sufficiently matured, and that they cannot conSciences at Paris, describing Gehin and Re- sequently be fecundated. The fish should my's modus operandi and its astonishing results. therefore be restored to the water for a few The sensation which this paper created was days. extraordinary, amongst the public as well as in the Academy; and surprise was generally expressed at the singular fact that it should have fallen to two uneducated fishermen to show the practical value of a discovery known to the learned for nearly a century. 5. Take a male and hold him in the same way; press with the thumb and finger gently down his belly, and cause the milt to spurt into the water. This milt will give to the water a whitish color. It spurts forth readily when perfectly butteraceous. 6. Both for male and female, the pressing operation must be repeated several times, until the fish be completely relieved of their respective burdens. 7. When these operations are terminated, stir up the water and its contents with the hand; or, which is better, with the tail of a male fish still bearing traces of the milt. The Academy, seeing at once the immense national importance of the two fishermen's proceedings, hastened to call the attention of the Government to it. The Government, on its part, after making proper inquiries and finding all that was said was true, resolved, as was plainly its duty to do, to have the system applied to all the rivers in France, and especially to those in the poorer provinces. Gehin and Remy were accordingly summoned to Paris, and taken at once into the employment 9. Before the mixing, the eggs will be obof Government at good salaries; their duties served to be of a pale orange-color and very 8. After a few moments' repose, pour off the water slowly and put in more. transparent; after it, they become brownish, ticular part of the stream, or if they be in reand a small black spot is perceived in the servoirs, it will of course be necessary to sup middle. 10. Change the water once or twice. 11. The fecundation being now complete, some of the eggs will be perceived to be white. These are the sterile ones, and must be picked out, otherwise they will corrupt the rest. ply them with food. At first the spawn of frogs will suit them very well. When they get stronger, the more substantial food of chopped meat, or the intestines of sheep and oxen torn into very narrow shreds, should be supplied. It is preferable, however, to procure an abundance of small fish, especially of those which derive their principal sustenance from The average weight of the trout, produced by the above means, is about four and a half ounces at the end of the second year, and nine at the end of the third. Having proceeded so far, the next operation is to provide for the preservation of the eggs. 12. Take a round box in the form of a warm-aquatic plants. ing-pan, with the centre of the bottom pressed in, so as to cause it to stand firmly. Let the box be made of zinc, to prevent rust. Let it be eight inches in diameter, with a lid one and a half high, opening with a hinge. Riddle it completely, with small holes, in all directions, and let the edges of the holes be quite smooth. 13. Place in the box a layer of fine gravel. 14. Then take about one fish's spawn of the fecundated eggs. 15. Close the box, place it in the bed of a current of pure water, cover it with shingle and pebbles, and leave it; but see that the water passes freely through it, as it is necessary for the eggs to be slightly agitated. This done, the operator must wait until the time shall arrive at which the exclusion, or hatching of the eggs, will take place. The period varies from two to four months. It cannot, however, be fixed with any precision, as it depends on the nature and quality of the water, the soil over which it flows, and other local circumstances. But there can be no difficulty on the point, as the box may be taken out and examined from time to time. Instead of a box, the eggs may be placed in a hole in the bed of the stream, and covered with pebbles. But, in that case, the progress of the transformation of the eggs cannot be followed. Besides, the box covered with pebbles is a better preservative against the admission of mud and dirt, which is injurious to the eggs. When the time of exclusion has arrived, the tail is first formed, and the little rents in the egg which its formation causes become the lower fins. The head afterwards appears at the other extremity, and the rents on either side form the upper fins. The lower part of the egg composes the belly; the upper, which subsequently breaks, the back. The pellicle which covers the embryon does not fall, but becomes developed with it. Modifications of the rules here given may be attempted. Thus, the holes in the box may be made so large as to enable the fish to escape when so disposed, which would do away with the trouble of watching them; secondly, they may be placed and brought up in large boxes containing coagulated blood, or other descriptions of food, so as to make a comparison botween their growth and those left at large. In fact, innumerable experiments may be attempted; but they will suggest themselves to the mind of the operator practically acquainted with fish. When the trout are destined to stock a river, it is advisable to produce them in one of its tributaries, where they will remain until they are active or strong enough to escape or resist the enemies which they find in the deeper waters of rivers. If they be destined for reservoirs or ponds, care must be taken not only not to place voracious fish with them, but to separate them aocording to their ages,- those of three years from those of two, and those of two from those of one. The reason for this is, that the larger trout devour the smaller ones. VI. It has been already stated, that in the course of a very short time, Messrs. Gehin and Remy, by the application of their system, succeeded in introducing several million trout into the rivers and streams of the Vosges. In a report to the Academy of Sciences, at Paris, by Dr. Haxo, in 1849, we read that, in addition to this," they had formed a piece of water belonging exclusively to them, in which they now have between five and six million trout, aged from one to three years; and the production of this year will increase that vast number by several hundred thousand." Since then, of course, the quantity has immensely increased: we scarcely like to express the estimate in figures, lest, from its enormity, it should appear exaggerated. 16. Keep the little fish in the box from eight to fifteen days, according as they are more or less numerous. Then set them at liberty. But 17. Take care not to let them go into water different to that in which they were born; as Shortly after Dr. Haxo had, by his commumore or less freshness or limpidity may be in-nication to the Academy, called public attenjurious to them. The water should, too, be tion to the discovery, very liberal offers were tranquil. made to Gehin and Remy, by the govern 18. If the young fish be confined to a par-ments of Spain and Holland, to introduce their system into those countries, but they declined to quit France. Since they have been taken into the service of the French government, they have stocked streams and rivers at Allevard, Pontcharra, Sassenage, Veury, Vizille, Bourg d'Oisans, Rives, Pont-en-Royans, Paladru, Lemps, St. Geoire, Arandon, Labuisse, and Grenoble, in the department of the Isère; in numerous places in the department of the Haute Loire; also, in the departments of the Allier, the Lozère, the Meuse, the Meurthe, the Haute Saône and several others. M. de Caumont, a gentleman of property, has experimented on their system in Normandy, with great success; as have also the director of the canal from the Rhone to the Rhine, in the vast reservoirs of Huninguen, and different noblemen and gentlemen in Burgundy, in Brie, in the neighborhood of Dijon, and in numerous other parts of the country. VII. Important as is the system described, Messrs. Gelin and Remy have invented another which will produce even more extraordinary results. It is well known that it is difficult to naturalize fish peculiar to one country in another country nor is it easy even to remove, with success, fish from one river to another in the same country. The introduction of carp into England, in the year 1514, was considered, it will be remembered, a very marvellous operation, and it is spoken of as such, in every Natural History of Fish; and though it has long been known, that fecundated eggs might be removed from place to place, it does not appear that, in any country, any great progress has been made in the stocking of rivers by that system. But Remy and Gehin have got over all difficulty, by their new fashion of removing, not the fish, but the eggs. To do this, these are the directions: and on other descriptions. And each exper iment has been perfectly satisfactory. IX. To make experiments on the different sorts of English fish, it will only be necessary to follow the very simple directions already given; or if in one or two sorts, any slight modification should happen to be required, they will be so self-evident as not to need de scription. As for the time of operating, that, of course, varies according to the species of the fish, and still more as to the temperature of the water. On this point, local knowledge can be the only guide. Care must, of course, be taken to provide, in streams or reservoirs, a sufficient supply of fish for the fish to feed on. Thus, when the system of artificial production is employed on an extensive scale, it will be necessary to breed some of the smaller descriptions of fish as food for the larger. In reservoirs, however, different sorts of food may be offered, by way of experiment. X. Although it has been stated, that it is necessary to place the fecundated eggs in the bed of a stream, it may be mentioned, that an eminent French naturalist, M. Coste, professor at the Collége de France, at Paris, has discovered that the stream may be done with 1. Take a box, similar to that already de-out; he has produced salmon in a tub. scribed. 2. Place in it a layer of fine sand; on that layer place one of pebbles of about the size of a nut; on the pebbles put a layer of fecundated ers. Then begin again with a layer of pebbles and of eggs, and continue until the box be full. 3. Plunge the box into water, to cause its contents to be consolidated, and send it off. 4. Take care, during the journey, to keep it in the open air. He has caused a large tub to be constructed, with conduits or canals, placed one be neath the other, in such a way that the water, on entering by the upper part of one canal, flowed to the lower part, and then descended into the canal beneath; and after flowing along it, descended into the one below, and so on, until at last it escaped from the vessel. In each canal he placed a layer of gravel and pebbles, and on these a quantity of salmon's eggs, fecundated by Remy and Gehin's sys tem, and sent up from the reservoirs of Huninguen, a distance of several hundred miles. The water flowed from a cistern, through an ordinary cock; and the only precaution taken was to keep the stream constantly going. In due time the exclusion or hatching of 7. The sand and pebbles placed in the the eggs took place, and the salmon are now boxes, must be perfectly clear of earthy sub-alive and well. 5. On arriving at its destination, divide its contents into other boxes, in the proportion of one female's spawn for each. 6. Place the boxes in the bed of a stream, cover them up, and leave them, as already described. |