Introduction

Given in Loving Memory ^Daniel M,trriman Crew Member on the maiden voyage of the R/V Atlantis Corporation Member, Trustee, Honorary Trustee eP Corporation Member, 1979- 8f Oceanographer, Writer, Editor, Fisherman, Educator, Mentor Woods Hole< Oceanographic Institution r^ nj LD as iu: ma u AMERICAN TIRE, OF TROUT i OTHER S BOOK." AMERICAN FISH-CULTURE, EMBRACING ALL THE DETAILS OF AETIPICIAL BREEDING AND EEAEING OF TEOUTi THE CULTUEE OF SALMON, SHAD AND OTHEE FISHES. BY THADDEUS NORKIS, AUTHOR OF "THK AMERICAN ANGLER'S BOOK." ILLUSTRATED. PHILADELPHIA: POETEE & COATES. LONDON: SAMPSON LOW, SON & CO. 1868. Entered, according to Act of Congress, in the year 1S68, by PORTER & COATES, in the Clerk's Office of the District Court of the United States, in aiid for the Eastern District of Pennsylvania. HEARS i DUSENBERY, STEREOTYPERS. SHERMAN A CO., PRINTERS. THIS BOOK IS RESPECTFULLY DEDICATED STEPHEN H. AINSWORTH, ESQ., IN APPRECIATION HIS PRAISEWORTHY EFFORTS TO ESTABLISH AS A BRANCH OF NATIONAL INDUSTRY. PREFACE THE numerous essays and articles on Fish Culture which from time to time, have appeared in periodicals and newspapers, clearly demonstrate the increasing importance of this branch of industry, and have promoted a spirit of curiosity and inquiry amongst intelligent people. Some of the first minds amongst our countrymen are giving serious thought as to the means of arresting the gradual extinction of valuable fishes, and restoring our failing and exhausted rivers to their former fruitfulness ; and are becoming convinced that the culture of water as well as of land, can be made to contribute largely to the supply of food required for our rapidly increasing population. Many of the short essays with their illustrations, which ap- pear in periodicals, claim the admiration and excite the curiosity of readers. But most of them, with their few and imperfect directions as to the mode of procedure, are calculated to mislead rather than direct the inquirer. With these facts before us, the writer, as well as other practical fish culturists, have declined many solicitations to contribute essays of limited space and matter to agricultural and other periodicals ; being impressed with the impossibility of doing the subject justice if thus abridged. In the mean time, those who have engaged in it and have a knowledge of the art, are applied to for information (5) vi PREFACE. so frequently, that much time and some pains are required to put the inquirer on the right road to success. The two little essays which have appeared in the American Angler's Book, and the fact of my having engaged in the business since its publication, has made me the recipient of numerous letters and caused a voluminous correspondence. This has also been the case with my friend Stephen H. Ainsworth, who informs me that the aggregate time employed by him in answering letters and writing essays since he commenced his experiments, would amount almost to a year. For want of directions as to the details of breeding and rearing trout, inexperienced persons who have commenced it have met with difficulties ; which has discouraged others who were anxious to engage in the business. With the pushing disposition and impatience of many of our countrymen, they frequently ignore the fact that in experiments we learn as much from errors as success. In view of these facts bearing adversely on this new branch of industry, and with a wish to promote it, I have, at the solicitation of several friends who sympathize in the desire to foster it, given all the necessary details to insure success in the culture of our brook trout ; being assisted, as the reader will find, by one who is as well versed in the art as any of those whose names have become prominent in this respect in France. I have also, as the reader will find in the following pages, drawn largely on my experience at the establishment I inaugurated in Warren county, New Jersey. The artificial propagation of migratory fishes which enter our rivers, is destined to be the principal means by which we are to restock our exhausted streams, and restore those that are rapidly declining, to their former fecundity : as well as in naturalizing valuable species in waters where they have hith- PREFACE. vii erto not been known. On this branch of the subject, I have brought to bear many years of close observation, and study of the instincts and habits of such fishes ; and have availed my- self of all the knowledge of others that has come within my reach. That my observations and directions may be intelli- gable to general readers, in laying such information before them, I have used as few technicalities as I consistently could. It will be seen that I have quoted largely from the great amount of useful knowledge elicited by the enterprising Com- missioners of Fisheries for the New England States. One of the reasons for laying such information before my readers is, that many interested persons outside of those states may not be able to avail themselves of the important facts which have been brought to light, as the reports alluded to are published only for their own citizens, or those who may apply for them to the Commissioners. As I have duly credited the various sources from which I have received information bearing on fish culture, I will make no further mention of them here, than acknowledge my indebtedness to Mr. Bertram's work, " The Harvest of the Sea," and Mr. Francis's book on Fish Culture. Although some statistics respecting salmon, and the con- sumption of Crustacea, will be found in this book, I have deemed that any account of fish that inhabit the sea exclu- sively, would be irrelevant to my subject. The publisher of an agricultural paper has urged my com- pliance with his request, to contribute a series of articles on trout culture, " if there were no state secrets." I might here suggest, that my starting a trout-breeding establishment for one of the subscribers to his paper (as I did for others, and that without remuneration), before I entertained an idea of writing this book, is an evidence that I have never had any viii PEEFACB. '' state secrets" on the subject. I have a poor opinion of the man whose narrow mind and heart would prompt him to withhold any knowledge that would benefit those who should engage in the business. The proprietors of a similar periodical, who offered to pay liberally for like contributions, and who must be aware of the small remuneration I shall receive for the labor bestowed on this book, I hope, will allow that such reward has been but a small inducement and that the ; reason assigned, that I could not treat the subject properly in the space allowed in their columns, is a substantial one. In conclusion of this preface, I can truly say that I have un- dertaken the task from a love of it, and a desire to diffuse a knowledge of the art. THADDEUS NORRIS. Philadelphia, July 1868 CONTENTS. CHAPTER I. INTRODUCTORY REMARKS ON FISH CULTURE. What it is. Its advantages over natural propagation. Time occupied in hatching. Number of ova of different species. Consequences of all the ova "producing fish that would come to maturity. Object of Fish Culture. Its antiquity. Practised by the Chinese and Romans. Artificial propagation discovered by Dom Pinchon. Rediscovered by M. Jacobi. Subsequent dis- covery of Joseph Remy. Alleged discoverers. Experiments of Shaw and Young. Patronage of the French government. Its effects on Scotch and Irish rivers. Its use as an adjunct in restoring American rivers to their former fecundity. Commis- sioners of Fisheries appointed by the New England States, and the States of New York and Pennsylvania. Experiment in arti- ficial propagation and hatching at Holyoke on the Connecticut. Experiments in trout breeding by Stephen H. Ainsworth. Progress in trout culture. Fish culture in France . P. 13 CHAPTER II. TROUT BREEDING. The Trout, Trout Ponds, etc. The Trout. Its adaptability to culture. Season of spawning. Spawning grounds. Appearance of the sexes at spawning time, habits and condition. Subsequent recuperation. Water-supply. Effect of the temperature of water on the time of hatching. Spring water necessary for incubation. Series of Ponds. Their shape. Method of shading them. Raceways. Their construction. Protection of them from muskrats. Screens. Depth and X CONTENTS. size of ponds. Transfer of fish from one pond to another. Estimate of number of trout for a given supply of water. Jere- miah Comfort's ponds. Stocking ponds. Procuring and trans- porting brood trout . . . . P. 26 CHAPTER III TBOUT BREEDING. Incubation and Treatment of Fry, Hatching apparatus. French and American plans. Supply of water for a given number of eggs. Hatching-house. Illustration with explanations. Filterer. Troughs. Nursery. Manage- ment of filterer. Washing gravel for troughs. Implements. Taking the spawn. Action of the female when about to spawn. Method of catching the fish on the spawning-beds. Indications of the maturity of the eggs. Manipulation. Placing the ova in the troughs. Packing and transportation of eggs. Manner of taking a large number of eggs for transportation from a trough. How to examine them. Illustration with explanations of the appearance of ova at different stages during incubation. Table showing progress of incubation with water at different degrees of temperature. Hatching out and progress in growth and ac- tivity of fry. Treatment of fry. Their food, and manner of ..... feeding them. Their disposition to escape. Transferring them to the nurseries. Their admission into the first pond. Trans- portation of fry 42 CHAPTER IV. TROUT BREEDING. General Remarks, Food for Adults, Profits and Statistics. Food of adult Trout. Curd, liver, maggots. Maggot factory. Allowance of food for a given number. Natural food. Stall feeding and its advantages. Trout culture a branch of farming. Facilities possessed by farmers. Will fish culture pay ? Instances of its being profitable. Estimate of cost of feeding on curd. Proposed trout breeding at Ingham Spring. Growth of trout. Description of Huningue, and M. de Galbert's estab- lishment, in France. Heidelberg. Fish cultural enterprise in Switzerland. Trout culture in the United States. Notice of Mr. Ainsworth's establishment. Description of Seth Green's . . 73 CONTENTS. xi CHAPTER V. CULTURE OP THE SALMON. The Salmon. Its instincts. Difference in appearance and size of those belonging to different rivers. Their former abundance and cause of decline in numbers. Their growth and adolescence. Migrations. Time of ova hatching in European and American rivers. Growth of the fry, with illustrations. Early fecundity of the males. Attempts at artificial propagation in the United States. Their naturalizzrtion. Fish ways, with illustrations. Salmon breeding. At Stormontfield. On the Dee. On the Galway. On the Doohulla. At Ballisodare. In Australia. Salmon statistics . . . . P. 102 CHAPTER VI. CULTURE OF THE SHAD. The Shad. Its instincts, and analogies to the salmon. Migra- tions. Former abundance. Incubation of its ova. Its growth. Its introduction into rivers flowing into the Gulf of Mexico, by Dr. Daniell. Hatching its spawn at Holyoke. Ascent by fishways over dam of Susquehanna Canal Company. Report of Colonel James Worrall. The Alewife . . 141 CHAPTER VII. NATURALIZATION OF FISHES. General remarks. SALMONID^E. The Brook Trout. Instances of its naturalization. The Lake Trout. Mr. Robinson's letter on its propagation. The Schoodic and Sebago Salmon. Extract concerning its habits and propagation, from Maine Fish Commissioners' Report. The Sea Trout of Canada. Advantages of naturalizing it. The Grayling. New species found in Michi- gan. The White Fish. Its excellence, habits, and manner of propagating. The Otsego Bass. Not a bass. The Smelt. General remarks. PEIICID.S:. The Rock Fish. The Crappie. The Black Bass of the Lakes. Its adaptability to naturalization. The Black Baas of the West and South. Its introduction into the Potomac. Mr. Wright's score of fish taken with the rod. Their naturalization in mill-ponds. SILURIIXE. Small Species. Their excellence as food. Manner of cooking them. Their proposed introduction into England. CYPRINIDJE. General remarks on. ESOCID^E. Injurious results from intro- ducing them . 178 xii CONTENTS. CHAPTER VIII. CULTURE OF EELS. Probability of eels being of sufficient importance to be cultivated. General remarks on eels. Eel culture at Comacchio P. 219 CHAPTER IX. CULTURE OP OYSTERS. The Oyster. An hermaphrodite. Its' fecundity. Its spawn or " spat," and its manner of incubation. Emission of the spat. and its destruction by marine animals. Importance of its find- ing something to fasten to. Places favorable to its growth. Transportation of seed oysters to the north. Growth of the young oyster. Chief object in the culture of oysters. Oyster Culture at Fusaro. Its antiquity. Its progress in France at the Bay of St. Brieuc and the Island of Ree. English and French ....... oysters. Decrease of oysters in Eastern States. Governor Wise's estimate of the area and value of oyster-beds in Vir- ginia 225 I. II. III. IV. V. VI. VII. VIII. IX. X. XI. XII. XIII. XIV. ... APPENDIX. NATURAL FOOD OF TROUT 23 .... MESSRS. MABTIN AND GILLONE'S SYSTEM OF HATCH- ING AND REARING YOUNG SALMON . . 241 CULTURE OF CARP 244 DISCOVERY OF ARTIFICIAL FECUNDATION BY JACOBI 245 ...... ARTIFICIAL SPAWNING-BEDS . . . 248 THE GOURAMI. ITS HABITAT, OR NATIVE COUN- TRY 250 COLD SPRING TROUT-PONDS . . . 264 CLOVE SPRING TROUT-PONDS . . . 272 CULTIVATION OF FUR-BEARING ANIMALS . 274 ...... AMERICAN FISH FOR ENGLISH WATERS . 278 Dr. J. H. SLACK'S TROUT-BREEDING ESTABLISH- MENT 287 .... STEPHEN H. AINSWORTH'S NEW HATCHING-RACE, FOR NATURAL PROPAGATION . . 288 CRUSTACEA . 290 SALMON HATCHING ESTABLISHMENT ON THE MIRA- MICHI . . 297 AMERICAN FISH CULTURE. CHAPTER I. INTRODUCTORY REMARKS ON FISH CULTURE. What it is. Its advantages over natural propagation. Time occupied in hatching. Number of ova of different species. Consequences of all the ova producing fish that would come to maturity. Object of Fish Culture. Its antiquity. Practised by the Chinese and Romans. Artificial propagation discovered by Dom Pinchon. Rediscovered by M. Jacobi. Subsequent discovery of Joseph Rcmy. Alleged discoverers. Experiments of Shaw and Young. Patronage of the French government. Its effects on Scotch- and Irish rivers. Its use as an adjunct in restoring American rivers to their former fecundity. Commissioners of fisheries appointed by the New England States, and the States of New York and Pennsylvania. Experiment in artificial propagation and hatching at Hoiyoke on the Connecticut. Experiments in trout breeding by Stephen H. Ainswofth. Progress in trout culture. Fish culture in France. IT may be asked, what is Fish Culture. The reply is, that it is the propagation of fish by artificial means, and the 2 (13) 14 AMERICAN FISH GUI/TUBE. protection of the young from the dangers to which they are exposed in their natural haunts ; assisting and in a great degree improving on nature. It may still be asked, can you assist or improve on nature? To this I respond, that if the fish culturist has the impregnated spawn under his own protection and supervision, it will be subjected to none of the casualties to which it is exposed in the stream where the parent fish deposits it. That no flood will sweep it away or cover it with dirt, sawdust, or tanbark. That no fish of its own or other species, sailing around like pirate craft, will devour it as it is ejected. That no eel or lamprey will burrow into the gravel-covered nest to make a dainty meal of its contents. That no duck, wild or tame, or long- legged wading-bird will gobble it up. That no water-rat, muskrat, mink, or other predacious quadruped will feed upon it. I would now in return ask my interrogator, if ten out of a hundred eggs should escape all these adverse contingencies and produce ten infant fish, if he supposes their own father and mother or other fish would hesitate for an instant to pouch them, or that aquatic birds which would have gobbled them up in embryo would spare them now? Does he think that three out of the ten infants would arrive at mature fishhood ? Close observers think not, especially if they were ten infant trout or salmon, each weighed down with the umbilical sac of aliment which it carries under its belly for forty or fifty days. But if the fish culturist puts the eggs of salmon or trout into his hatching-trough, he will likely get eighty or ninety young fish from a hundred. If trout, seventy or eighty of the fry INTRODUCTORY REMARKS. 15 may be grown to weigh a pound or more, in three years, and are worth seventy-five cents or a dollar a pound in market. If my querist reads scientific journals, he will see that Dr. Daniell, of Savannah, transported the fecundated spawn of shad across the country to a tributary of the Alabama, ten years ago, and hatched them out and stocked that noble river and its branches with this favorite fish. If he only reads the newspapers, he must have found out that Seth Green sends trout spawn by thousands to all parts of the Northern and Middle States. That Dr. Fletcher has brought salmon eggs from the British province of New Brunswick to stock the salmonless rivers of New England, and that salmon spawn has even been sent from England to Australia to introduce that noble fish there. That barren salmon rivers of Ireland and Scotland have by means of fish culture been restored to their former fecundity; and rivers, and even brooks, that before had no salmon, have been made fruitful of them. There is scarcely a month irf the calendar in which fish of some genus or other do not spawn. Some deposit their eggs on stones, brush, or aquatic plants, the ova adhering by a glutinous substance which surrounds them. Others, as the salmon family, excavate their nests on gravelly beds in running water, cover their spawn and leave it to the care of mother nature. Some, such as the stickleback, the sunfish, the black-bass, and others of the perch family, build nests and stand guard over them. Others, including some species of Siluridas, known as catfish, have a parental 16 AMERICAN FISH CULTURE. care for their young, and lead them about as a hen does her chickens. The time occupied in hatching the spawn also varies. That of the salmon requires from forty to over two hun- dred days, according to the temperature of the water; while the spawn of the shad in water at 75 hatches in fifty-two to sixty hours. The number of eggs produced by different species vary A as wide as the time of incubation. salmon of ten pounds only gives ten thousand eggs, or a thousand to each pound of its weight; while a good-sized codfish gives a million, a herring forty or fifty thousand, and a five-pound shad a hundred thousand. But a small percentage of ova produce fish, as it is food for fishes and other aquatic animals. If all the fish eggs produced were hatched and the fry arrived at mature age, the seas would be so full that they could not be navigated, and rivers and lakes would be plethoric. The object of fish culture is to profit by knowledge of the facts I have mentioned, and to turn a portion of the waste of piscine life to human acftount. As far back as our knowledge of the Chinese extends, we find that fecundated fish spawn with them has been an article of traffic. The manner of procuring it is by placing fagots on frames permanently fixed in waters where fish are accustomed to spawn. At the proper time the fagots are collected with the spawn adhering, and the ova either hatched out by those who collect it, or is sold and transported in water. The flooded rice-fields are frequently used for raising the young fish. I would here remark that INTRODUCTORY REMARKS. 17 this spawn must necessarily be mostly of species belonging to the carp family, which abound in China. By this mode of culture, fish are made so abundant and cheap there that they are the chief food of the people. The Romans, vying with each other in the splendor of their feasts, left no means unemployed of spreading their tables with the best fish their climate afforded, and fish culture was brought into requisition to a great extent to supply this demand. M. Jourdier, a French writer on this subject, says of Lucullus, " at his house at Tusculuni, on the shores of the Grulf of Naples, he dug canals from his fishponds to the sea. Into these canals freshwater streams were led, and pure running water thus kept up. Sea-fish that breed in fresh water passed through the canals into his ponds, and stocked them with their young. When they attempted to return to sea, flood-gates barred their egress at the mouths of the canals, and while their progeny were growing the parent fish supplied the market." The value of the fish kept in these ponds, it is stated, amounted to a sum which in our money would be equal to two hundred and fifty thousand dollars. Fish culture appears to have fallen into disuse after the fall of the Roman republic, as we find no mention of it until the fourteenth century, when, according to M. Jourard, Dom Pinchon, a monk of the Abbey of Reome, discovered the art of breeding fish in wooden boxes, the ends being of wicker work and the bottoms covered with sand, in which excavations were made and the ova deposited. The art was rediscovered about the year 1763 by Jacobi a German. 18 AMERICAN FISH CULTURE. Bertram, in his " Harvest of the Seas," says : " Jacobi, who practised the art for thirty years, was not satisfied with the mere discovery, but at once turned what he had discovered to practical account and ; in the time of Jacobi great atten- tion was devoted to pisciculture by various gentlemen of scientific eminence. Count Goldstein, a savan of that period, also wrote on the subject. The Journal of Hanover had papers on this art, and an account of Jacobi's proceedings was also enrolled in the Memoirs of the Royal Academy of Berlin The results arrived at by Jacobi were of vast importance, and obtained not only the recognition of his government, but also the more solid reward of a pension." It is strange that so important a discovery should not have produced more permanent results, and that it should not have been followed up at that time with, the same success which has attended the after-discovery of Joseph RemyJacobi's mode of hatching the ova of salmon and trout, was the same as that of his predecessor, Dom Pinchon, using gravel, however, instead of sand in his hatching-boxes. Dom Pinchon is the first of whpm it is recorded that he expressed the ova and fecundated it with the milt of the male fish the Chinese and Romans had not arrived at this ; point in their pisciculture. In the early part of the present century there was con- siderable controversy amongst naturalists and fishermen in Great Britain, concerning a little fish known as the parr; whether it was a distinct species or the young of the salmon. Also, whether the young salmon arrived at its smolt INTRODUCTORY REMARKS. 19 state and made its first migration to sea the second or third summer of its existence. To decide these points of dispute, Mr. Shaw, of Drumlanrig, and Mr. Andrew Young, of Invershin, Scotland, about the year 1834 bred salmon artificially in wooden boxes. It is likely they were aware of the plan pursued by Jacobi and followed his example, as their mode was not heralded as a discovery, and was not different in any essential point from that of Jacobi. I will here say that the result of their experiments proved the parr to be the young of the salmon, and that the contestants were both right as to the period of its first migration to sea, as it has been clearly ascertained that a portion of them, even of the same brood, will migrate the second summer, and another portion defer their journey until the following year. It is stated also, that pisciculture was practised in Norway previous to the experiments made by Shaw and Young, and that James Hogg, the Ettrick Shepherd, was one of its dis- coverers. It is useless to dwell on facts that the most obtuse have not failed to notice. I allude to the gradual extinction and banishment from our rivers of the more valuable species, and the consequent enhanced value of such fish in our markets, rendering them almost unattainable by persons of moderate means. The old countries of Europe, though more provident, have suffered, more or less, in the same way, and fish as food has become a question of vast importance. The French government has fostered fish culture chiefly for this reason, and to such purpose that in a few years there will scarcely be an acre of barren water in the 20 AMERICAN FISH CULTURE. empire. Not only fish but oysters, crayfish, and other Crustacea are being multiplied by this new science. The discovery of Joseph Remy has produced practical results which did not follow those of his predecessors. This French peasant, who gained a livelihood from the Moselle, its tributaries, and other streams of his native district, La Bresse, lamenting the sure extinction of the finer kinds of fish; by long and anxious vigils became convinced of the outer impregnation of the spawn and all the adverse vicissitudes to which it and the young fry were exposed. His experiments based on these observations were successful beyond his anticipations, and in 1849, when his doings and those of his companion Gehin were brought to the knowledge of M. Coste, professor of Biology in the College of France, improvements were made in the manner of hatching the ova, the patronage of the government was secured, and the present establishment at Huningue, and subsequently its branches, were inaugurated. The effects of liberal and judicious government patronage have not only been spread over France, but its benefits have reached all parts of enlightened Europe ; and our own country is now resorting to this new science to restock its exhausted rivers, and adopting it as a branch of industry. In a chapter devoted to the salmon I shall endeavor to give a summary of what has been done in Scotland and Ireland in cultivating that valuable fish. In this country, our utter disregard for the bounties of nature so wonderfully lavished upon us, and our inordinate rage for internal improvements, have caused our state gov- INTRODUCTORY REMARKS. 21 ernments rather to legislate for the extinction than the protection and continuance of the finer species of migratory fishes. Individuals have been allowed, and companies have been chartered, to construct impassable dams, driving back salmon and shad from their spawning-beds; and not only above, but below such barriers most of our rivers have become as barren of such fish as if they had never resorted to them. These are not the natural consequences of civilization and progress, as some would urge, but rather of bar- barism and reckless improvidence ; and at last, when a shad or a pound of salmon is sold for twenty times the price it brought when we ceased to be colonies of Great Britain, our legislators have set seriously to work to regain for us the liberal provisions of nature which they have thrown away. Our separate interests as states, it is to be feared, will defer or prevent the restoration of many rivers to their former fruitfulness, as many of them form the boundaries between, or flow through, several states. The New England States, notwithstanding, have at length set to work with a will, and, from all we can gather from the reports of their fish commissioners, there is much good feeling and concert of action. The joint commission have defined the part to be taken by each state. Those to whose territory the spawning-beds of the long rivers are confined, have agreed to stock them with shad and salmon, and are using the fecundated spawn of these fish to do it the more speedily. The enormous number of forty millions of young shad were hatched out by Seth Green at Holyoke on the Connecticut 22 AMERICAN FISH CULTURE. last summer and turned into the river. The intermediate states are to construct efficient fishways for the passage of the fish to their spawning-grounds. Those owning the mouths of the rivers are to provide against destructive fishing, and give a free passage to the upper waters. All the states referred to have enacted laws, or revived those that were obsolete, to promote the object in view. It is devoutly to be hoped that a liberal spirit will prevail, and that the energy which now characterizes the commissioners will continue until the much-desired end is attained. I shall have occasion to refer to the reports of the commissioners of each state ; that of Maine is lengthy, and contains much of interest to the friends of the enterprise ; the Vermont report is also interesting, and that of Massachusetts instruc- tive, practical, and spirited. The state of New York has also appointed fish commis- sioners. It is to be regretted that Stephen H. Ainsworth is not of the number. Still, from the reputed energy of Mr. R. B. Roosevelt and the known experience and skill of Mr. Seth Green, we may expect favorable results. If the latter should go to Canada or New Brunswick to manipulate the salmon, and then have charge of the hatching, there is no fear that the Hudson and the streams flowing into the St Lawrence and the Lakes will be without salmon for many years after the fry are produced. Of course fishways are to be constructed, and laws for the protection of the fish and * Since writing the above I have been informed that Ex-Governor Seymour, who, it is said, takes much interest in the matter, lias been added to the commission. INTRODUCTORY REMARKS. 23 fry rigidly enforced, or no permanent good will come from merely stocking the rivers. Pennsylvania, on the 30th of March 1866, passed a law making it incumbent on the owners of dams on the Susquehanna and its tributaries, whether companies or individuals, to erect efficient fishways over such dams by the first of December of that year, and a competent engineer was appointed to see the law enforced. The companies who had bought the different internal improvements from the state, contended that they were purchased without encumbrance, and resist the law, as some other companies also do, and it is now a matter of litigation. One, however, the Susquehanna Canal Company, acquiesced and constructed a fishway under the supervision of the engineer appointed. The report of this gentleman to the legislature shows that shad in numbers and of large size ascended the fishways in the spring and summer of 1867, and were taken as high up as New Port on the Juniata; the number being vari- ously estimated from ten thousand to eighteen thousand. Numerous fry were also seen in the river during the latter part of the summer, as well as some bodies of Shad that had died, as they frequently do, from the exhausting effects of spawning. This proves conclusively that shad will ascend rivers to new spawning-beds if suitable fishways are provided. To introduce them into tributaries which they may not enter, or to repopulate the Susquehanna the more speedily, artificial propagation must of course be resorted to. If it should be decided that the Act of March 30th 1866 is not constitutional, it remains for the state to defray 24 AMERICAN FISH CULTURE. the cost of restoring to the people who dwell on the river in question and its tributaries, the privileges of which it unjustly deprived them in constructing internal improvements, or granted away to corporate companies. This the New England States have already done, and when appro- priations have fallen short in effecting some desired object, commissioners have footed the bill, trusting to the liberality of their state to refund the difference. Although our state governments have been tardy in availing themselves of the benefit to be obtained from this new science, individual curiosity and enterprise have not been idle. From a lack of knowledge of the requirements and mode of procedure, however, success in most cases has been small or unsatisfactory, and experiments have been almost or entirely confined to breeding trout. Our most zealous and able fish culturist, Stephen H. Ainsworth, commenced ten years ago with whatever light he could get on the subject from newspapers and periodicals, generally accounts of what was doing in France. With a supply of water that does not fill an inch auger hole, and of exceedingly varia- ble temperature, it may be said, he has taught himself this science, discovering many of its hidden truths not recorded by French fish culturists, and is now our chief authority on all matters pertaining to it. He imparts the knowledge he has gained by years of unwearied observation, to all inquirers, and has done much by his letters and newspaper contributions to create an interest in the art. He has been my preceptor; all that I shall endeavor to teach in a chap- ter on trout breeding are lessons which I have learned of INTRODUCTORY REMARKS. 25 him, or from my own experience which grew out of his teachings. I will give a brief description of his establish- ment and that of his neighbor, Seth Green, in a subse- quent chapter. Breeding and raising trout for private use and to supply our markets is destined to become a national branch of industry, and many who possess the requisite natural advantages are now turning their attention to it. I shall notice the efforts of many of those who have commenced it, under its appropriate head. I have alluded on a former page to the fact that the French government is making every effort to extend this branch of industry, so that waste waters which were entirely barren, are now beginning to be more productive than the same area of cultivated land. The fish ponds of Doombes extend over thirty thousand acres. Under the advisement of proficient persons appointed by the government, all kinds of waters are stocked with fish suitable to them : carp, perch, eels and pike for sluggish streams, lakes and ponds; trout for the bounding cool brook, and the salmon for the clear swift river. France being a Roman Catholic country, with its many fast days, fish are more requisite than where Protestantism prevails; therefore, fish of the cheaper kinds are more in demand than with us, and are used where meats would be bought in our markets. The cultivation of oysters, a>s well as Crustacea, is fostered by the government; so, also, is that of sea-fish. Experiments are even being made on the sea coasts, in the propagation and rearing of the finer kinds of turtles. 3 26 AMERICAN FISH CULTURE. CHAPTER II. TROUT BREEDING. THE TROUT, TROUT PONDS, ETC. The Trout. Its adaptability to culture. Season of spawning. Spawning grounds. Appearance of the sexes at spawning time, habits and condition. Subsequent recuperation. Water-supply. Effect of the temperature of water on the time of hatching. Spring water necessary for incubation. Series of Ponds. Their shape. Method of shading them. Raceways. Their construction. Protection of them from muskrats. Screens. Depth and size of ponds. Transfer of fish from one pond to another. Estimate of number of trout for a given supply of water. Jeremiah Comfort's ponds. Stocking ponds. Procuring and transporting brood trout. THE artificial hatching and raising of fish, as I have .already intimated, has, with few exceptions, been confined in this country to brook trout. These are not only fish of the rarest beauty and most delicate flavor, but they also command the highest price in market and afford the greatest sport to the angler. Moreover, their spawn is more easily procured and can be hatched in a manner more re- sembling that of nature, than the ova of any other freshwater fish. The season of spawning with trdtit extends from the latter part of October to the middle of December; and in some cases where the water does not freeze, as in Caledonia TROUT BREEDING. 27 creek, in New York, to the middle of March.* When they have a choice of spawning-grounds, trout will seek shallow water of gentle current, with pebbly bottom, or the lower end of a ripple where the water is almost still. To occupy such places, they will run out of deeper water either up or down stream, leaping over an obstructing log, or wriggling through water half the depth of their bodies, the males preceding the females some days. At this season the * About the 1st of May (of this year) I visited Mr. A. J. Beaumont, near New Hope, Pa., for the purpose of inaugurating a troutbreeding establishment. He has a spring which supplies the power for a paper and grist mill, the water flowing in a raceway about five hundred yards to the mill site. This race is well stocked with trout, and the water is of such unvarying temperature that the fish know no summer or winter. On taking a few fish with the fly I found that more than half of the females presented the slender body and peculiar appearance of fish that had lately spawned. When I mentioned the circumstance to Mr. Beaumont he informed me that only three days before, while cutting water cresses at the spring, his son removed a stone that lay at a slight angle with the bottom, and found beneath it a large number of trout spawn. On examining the ova he could not detect, with the naked eye, any formation of the young fish. The conclusion to be deduced from this and similar facts which have come under my observation, is that the more equa- ble the temperature of the water, the longer will the time of spawning extend into the spring of the year, and that trout taken from cold forest streams, where they spawn only in the fall, and placed in unvarying spring water ponds, will, in successive generations, breed later and later, until they take on the habit, in this respect, that prevails with the trout in Mr. Beaumont's raceway and in Caledonia creek. 28 AMERICAN FISH CULTURE. sexes are easily distinguished, the males putting on a de- cidedly orange tint, their fins brilliantly red, with the first two or three rays of the ventrals and anal vividly white j while the females are of a sober silver gray. Their forms also differ at spawning time the males deep-bodied, slab- sided, and long-headed ; the females with the usual small head, and the looked-for rotundity and protuberance of abdomen. The males show all the ardor of quadrupeds on such occasions, and in their contests for the favors of the shy spawners the result is sometimes fatal. I have picked up males at the outlet of my pond whose scarred and gashed sides left no doubt as to the cause of their A death. greater part of the time of the male is occupied in driving off rivals, and fish that wait at hand to devour the eggs as they are dropped. A male may have milt enough for several females of his own size, consequently, his milting extends over a period of a week or ten days ; during which time he may have A two, or three mates in succession. female when she is mated and her spawn matured, deposits it all in a day or two, or in three days at most; if her mate is so small that his milt is exhausted before she is done spawning, she seeks another companion. As the time for spawning approaches, the fish fall off in flesh and flavor, which they do not generally regain until late in the following spring. When they have access to brackish and salt water, as on Long Island, where they find shrimp and small fry, this may be in March. In freshwater ponds where there is much feed, as the larva of flies, TROUT BREEDING. 29 worms on certain weeds, and minute Crustacea, or when they are bountifully fed, they are edible in April. In the streams of the forest however, they are seldom in season before the 10th of May. The peculiar habits, appearance, and condition of trout at spawning time can be observed in clear ponds where they are kept for breeding, as well, or perhaps better, than in their wild haunts. Water Supply. Spring water, whether hard or soft, if not impregnated to any great extent with mineral, is best, not only for hatching but also for supplying ponds. The warmer the water the more rapid the incubation, though a low temperature conduces to the healthy condition of the ova during this process, as well as to that of the young fish until the umbilical sac is absorbed, as it is not favorable to the growth of byssus and confervia. In proof of this I would instance the small percentage of eggs lost in incuba- tion by Mr. Ainsworth ; though much of his success in hatching is to be attributed to his experience in expressing the spawn and milt, as well as the care he bestows on the A ova after taking them. spring with a deep source will furnish water of almost unvarying temperature, and will indicate the mean of the atmosphere in its locality. In the neighborhood of Philadelphia, this is about 51 or 52. For hatching, the water should never be above 54 ; 46 or 47 is. perhaps the best temperature. Spring water is almost indispensable in hatching, as few or no brooks are uniformly clear, or have not more or less dirt or vegetable fibre curried along by the current. It is to be supposed that the beginner has a spring of 3* 30 FISH CULTURE. certain flow for hatching, and perhaps a cold brook which he can also use in supplying his ponds. He will therefore wish to know the size his ponds should be, and the best form. Before I give any directions on incubation and its appliances I will treat of ponds, remarking by the way. that if one uses brook water to increase his supply, he should not introduce it, if avoidable, into his first pond where the small fry are kept, and should make some con- trivance for shutting off the brook or confining it to its usual volume in time of heavy rains. He should do this, not only that he may keep the water in the first pond at its usual temperature, but also to prevent dirt from being washed in, which will soon foul the bottom with mud. The plan usually pursued with those who raise trout as a " crop," is to have a series of ponds connected by race- ways, the latter being used as spawning-grounds for the fish. At least three ponds are required. The first for the young fish from the time they are taken from the hatching- trough or nursery, until they attain the age of eighteen or twenty months. The second pond for the same brood for the next twelve months, at the end of which time they will be thirty or thirty-two months old. The third pond for the same fish from the age last mentioned, until they are three years and a half old. From the last pond it is supposed they are to be taken for sale or the proprietor's table. It will be observed, that when the last pond is vacated the trout from the second pond will occupy it, that the second will be occupied by the fish from the first, and the first pond by the new brood from the nursery. TROUT BREEDING. 3] It requires careful forethought, that the size of the ponds may be in accordance with the supply and temperature of the water. The cause of failure in most cases has been where persons have attempted to supply large ponds with a diminutive stream ; thus exposing a large area to the heat of a summer atmosphere and the rays of the sun. The shape also of the ponds has much to do with the tempera- ture of the water; an oblong is preferable to a circle; if the width of the pond is one-tenth of its length, so much the better, as the water passes through quicker, and retains its coldness to a greater degree. Trees, though they may shade and serve to beautify, cause much annoyance, as the leaves falling or being blown into the water, sink and accu- mulate on the bottom, or are carried by the current^gainst and clog the wire screens which are placed in the outlets A to keep the fish in the ponds allotted to them. cheap and efficient method of diminishing the surface exposed to the sun is with floats or platforms made of rough boards, moored in the ponds ; these also make an acceptable shade and hiding-place for the fish. The race-ways, which, as I have before remarked, are the spawning grounds of the fish, should be five or six inches deep, from two to three and a half feet wide, and from twenty to sixty feet long, according to the size of the ponds and the supply of water. The bottoms of the race- ways should be covered to the depth of three inches or more with fine gravel for the trout to make their nest* in. The sides should be of boards an inch thick and twelve inches wide. If the slope of the ground is such that there 32 FISH CULTURE. will be much fall between the ponds, the water should dis- charge at each outlet into a box or pool, and flow through the race below in a gentle current. The water is thus aerated without creating a rapid, which is unfavorable to a spawning-ground. When the supply is small, the water in a pond may back half way up the race which feeds it. At the end of each raceway strips should be nailed perpen- dicularly against the board sides, one set on each side at the entrance into the pond, and another set three or four feet above, so that wire gratings can be slipped in to secure the spawners when they are driven from the race above. I would here impress on the beginner the necessity of not allowing too rapid a stream in the raceways, or having the water shallow, or gravel in the ponds where they enter. If he does, the trout may find a more acceptable spawning- place in the upper part of the pond, even in broad sun- shine, than in the covered race above ; and if he attempts to secure his spawners at the head of the pond with a seine, he will frighten back into deep water those that might, perhaps, enter the raceway. If the sides of the raceways are lined with boards, it will not only secure them from the effects of frost and prevent dirt from falling in, but will also be a protection A against nmskrats. hundred feet of hemlock or third quality pine will cost but a trifle, and will line a raceway fifty feet long. This is also the most effectual way of protecting the sides of ponds frotn these pests. On perfectly level ground, however, if the water comes within a few inches or a foot of the top of the bank, there is no harbor TROUT BREEDING. 33 for them, as they burrow uuder water only where the bank is high enough above it to allow them room fortheir nests. In severe weather, when the ground is covered with snow, muskrats are driven by hunger to feed on grass, which may even then- be found on the margin of spring water, or they may come into it for the warmth it affords. When they nib the grass, much of it is set adrift and clogs the wire screens, at least I have found it so in my experience. On this account it would be well to have the margin of the A raceways and ponds gravelled. great inconvenience is experienced in keeping the screens at the outlets from be- coming clogged with leaves and floating trash. There should therefore be a coarser screen to act as a leaf catcher, placed before each of those intended to keep the fish in their respective ponds. Seth Green, at Caledonia creek, that he may prevent the fish in his ponds from running up into the mill-pond that supplies them, has a water-wheel turned by the current at the head of the raceway, the edges of the buckets or paddles coming so close to the concavity of the frame in which it revolves, as to keep the fish from ascend- ing, while those from above can descend between the buckets. Floating grass and leaves also pass without obstruction. This contrivance, however, although it will keep the large fish in the last pond, will not prevent those of pond No. 1 from running down into No. 2, and the fish of both from getting into pond No. 3, where the yearlings would be devoured. POND No. 1 being for the small fry, from the time they leave the hatching-troughs or nursery, until they are somec 34 FISH CULTURE. thing over eighteen months old. the water in it should not be more than six inches deep at the upper, and two feet deep at the lower end. Young trout delight in shallow water, and will therefore be found mostly where the raceway enters ; as they grow larger they will seek the deeper water at the lower end of the pond. The bottom of this pond should be covered to the depth of two or three inches with coarse gravel. POND No. 2. The fish, when they are old enough to enter this pond, will require deeper water and more room. It may therefore be a third or a half longer, two or three feet wider, and have an average depth of three feet; thus containing four or five times as many cubic feet of water as pond No. 1. The depth may be more uniform ; care being taken to have a good depth and no gravel where the race enters, so as to offer no inducement for the fish to spawn in the pond. The trout, spawning for the first time a few months after entering this pond, and being still small, and giving not over three hundred eggs to each spawner, it is not requisite that the raceway supplying it should be as long or as wide as that leading into the next pond below. POND No. 3 should contain double or three times the number of cubic feet of water of the preceding, and have an average depth of five feet. This, as well as the other ponds, if it can be so arranged, should have a flume in the bottom, so that it can be entirely drained if sufficient mud should accumulate to make it desirable. The fish entering this pond when somewhat over two and a half years old, will give double or thrice as many ova as they did the pre- TROUT BREEDING. 35 ceding autumn. On recovering condition the following spring they will average about a pound, and are then fit for the market or one's own use. If any are left they will likely prey on the smaller of those from pond No. 2 when transferred to this. For it must be borne in mind that some are of slow growth from the egg, and will not be half the size of others of the same age when driven into this pond, or one-fourth the size of some a year older that may remain in it. It is therefore better to clear it of all its occupants before those from No. 2 are admitted, as it is not safe to calculate that trout of a pound, or it may be a pound and a quarter, will not swallow those of four ounces ; I have had ocular proof that they will. How many of the latter size were devoured by the larger at night, or when I was not observing them, it is hard to tell. If, therefore, one should wish to keep trout beyond the age of three and a half years, it would be better to have a fourth pond and transfer them to it. The water having answered the purpose of hatch- ing and supplying the stock ponds, where the fish are, I might say, stall fed, may now be used for a miniature lake if not too large, where the fish would find their own feed, and where the owner might indulge his taste for the pic- turesque and have a fly cast for himself and friends. The proper time for transferring the fish from one pond to another is the latter part of August. Pond No. 3, as I have already remarked, by that time will have been vacated and can be occupied by those from No. 2 ; pond No. 2 by those from No. 1 ; and No. 1 by the new brood from the nursery. After the 1st of September trout should not be 36 FISH CULTURE. eaten, as they are then getting out of season. If transferred about this time or a little earlier they are not so heavy with spawn as to be affected by change of habitat, and will be- come accustomed to their new home by spawning time. In the proportions I have given for ponds, the fish are more under the control of the owner and can be fed with greater certainty and regularity than in those which approach a square or circle in shape, and the ponds can be easily dragged with a seine so as to secure every fish if necessary to clear it. As the fish in pond No. 1 do not spawn at the age they inhabit it, a raceway with the requisites for breeding is not necessary. The water should be led in through two or more shallow rills from a foot to two or three feet wide, according to the supply. If bulkheads made by setting narrow boards edgewise, put out from each side alternately, nearly to the middle of the rills, they will create a zigzag current and form eddies for the fry. These bulkheads may be set from four to eight feet apart, the distance apart being proportioned to the length of the races. The bottom of the race, though, should also be covered with gravel. This question of course will present itself to the reader : How many trout will a supply of given volume and tempera- ture keep in healthy condition ? In reply, I will cite a case on which I have in a great degree based my estimate; I have already referred to it in " The American Anglers' Book." Owen Desh, at Hellertown, Penna., has a spring in his garden, the temperature of which we will suppose to be 51, and the volume one and a half inches square; it flows TROUT BREEDING. 37 through a trough about twenty-four feet long and two feet wide, at a depth of eighteen inches, which gives seventytwo cubic feet of water. His usual supply of trout in it is, or was, eight hundred, although at times he has kept twelve hundred, varying in size from nine to thirteen inches. If we take seven hundred and twenty fish as the minimum, it gives ten trout to each cubic foot. These trout were kept in thriving condition on one or two quarts of curd fed to them on alternate days, and not over a dozen died during the summer. If the reader takes this as a basis he can make his own calculations, remembering that it is not the quantity of water a fish has to live in, so much as its lifegiving qualities. If Mr. Desh's supply had been spread out over an acre at a depth of three feet and exposed to the rays of the sun and a summer atmosphere, it is doubtful whether the water would have been sufficiently oxygenated to sustain trout at all. Therefore, if trout are to be grown as a crop, the fish culturist should be careful how he in- dulges his fancy for the ornate in making his ponds. It would be practicable for any farmer having a spring of low summer temperature, flowing a full square inch, to have a series of three small ponds, to keep fifteen hundred year- lings in the first, a thousand two year old in the second, and six or seven hundred three year old in the third. My friend Jeremiah Comfort, near Spring Mills, on the Norristown Railroad, has a supply of sixteen square inches (not sixteen inches square). In laying off" his ponds last fall I gave the sizes as follows : Pond No. 1 ; sixty feet long, eight feet wide, four inches of water at the upper, and 4 38 FISH CULTURE. twenty inches at the lower end, contents, four hundred and eighty cubic feet, to sustain nine thousand six hundred young fry, or twenty to each cubic foot of water, from the time they leave the nursury until they are eighteen or twenty months old. Pond No 2; thinking that the water would increase from one to one and a half degrees in temperature in passing through pond No. 1, we estimated that a cubic foot in this would sustain three trout from the time they were twenty until they were thirty-two months old, and allowing for loss or sales, reduced the estimated number We for this to eight thousand one hundred. accordingly laid it off ninety feet long, ten feet wide, and intend filling it to the average depth of three feet, which gives twenty- seven hundred cubic feet as its contents, and three fish to each cubic foot. Pond No. 3 ; assuming that the summer temperature of the water in this would seldom rise above 56 or 58, we thought that a cubic foot would sustain one trout, and again making allowance for losses or sales, reduced the estimated number to six thousand four hundred and eighty, and so staked off the pond one hundred and twenty feet long, twelve feet wide, and allowed for an average depth of four and a half feet. I would here remark that Mr. Comfort has a spring branch rising three hundred yards away, flowing at right angles and joining that already described, the supply being double of that just given. This he intends using as accessory in filling his third pond. The united streams flow also through an ice pond below, which he will stock with trout. If one is desirous of having ponds of the largest capacity TROUT BREEDING. 39 a diminutive stream will supply, he should deepen them rather than increase the area. The deeper the water the cooler it will be at the bottom in summer and the warmer in winter. Stocking-Ponds. The best time to procure brood trout, of course, is when the streams are low, and the nearer the time of spawning the more easily they are captured. If on the spawn-beds, this is easily done in the small streams they generally seek for that purpose. Last November I was present when P. H. Christie, at the head of Fishkill creek, in Dutchess county, New York, with only one assist- ant, took one hundred and twenty in an hour and a half; we manipulated those that were ready to spawn the same afternoon, and got five thousand eggs from them. Two weeks before, Mr. Christie, in going over the same length of the stream, had taken four hundred before noon. The best kind of net for the purpose, is what is termed a set or stir-net. It has a straight strip about four feet long which rests on the bottom, and a bow of ash or white oak, the ends being inserted in the strip. The bag of the net should be of coarse gunny cloth, to avoid injuring the gills of the fish, as they are apt to stick their heads through the meshes of the ordinary net, and so injure themselves in that vital part. If taken with artificial flies of moderate size, they are seldom hooked so as to injure them. A Transporting Adult Trout. barrel is a good im- promptu vessel for this purpose; a piece four or five inches square being sawed out of the head, and a strip nailed across the piece, so that it can be replaced without a chance 40 AMERICAN FISH CULTURE. of its falling in ; large gimlet holes are also to be bored in it, so as to afford air to the fish when it is in its place. The water should be renewed as opportunity offers, and the state of the weather demands, and may be oxygenated by dipping some out and pouring it back, elevating the vessel from which it is poured as much as possible for that pur- pose. The usual place for a barrel when so used in carry- ing trout by railroad, is the baggage car, and as the barrel is necessarily wet outside from jolting (and the more jolting it gets the better), it should be set near the side door of the car, where there is a draft of air, which tends largely to keep the water inside cool. In moderate weather in June, I have thus taken a hundred and fifty trout in a forty gallon barrel two-thirds full of water, sixty miles without re- plenishing it. When ice can be had, a piece may be dropped in occasionally to keep the water cool. Too great a degree of cold, however, is injurious. I have had trout to die in my ponds some days after transporting them as I thought safely, from the effects of what I considered too lavish a supply of ice. Pump water should never be used in replenishing ; I have seen fifty trout turn on their sides as A soon as it was poured into a barrel. bellows may be used for aerating the water, by inserting the nozzle the whole A depth and blowing. zinc vessel on this principle is used in England, the air being pumped through a tube opening into the bottom of the vessel. The same principle was applied, though differently arranged, by Barnuni, at his old Museum, for aerating the water in the aquaria in which he kept trout. When taking them in a wagon, the barrel TROUT BREEDING. 41 or vessel should be rocked to and fro, while stopping, so as to oxygenate the water. For a small number of fish a bucket or pail can be used. Mr. Christie uses ordi- nary milk cans holding about twenty gallons in transporting trout in a wagon, carrying from fifty to a hundred in a can. When trout cannot be procured for stocking ponds, and one is willing to wait a few years, much trouble and expense can be saved by hatching the spawn. This can be procured at about ten dollars per thousand of Seth Green, Mumford, Monroe County, New York ; or of Stephen H. Ainsworth, West Bloomfield, New York; or P. H. Christie, Clove, Dutchess County, New York ; or Dr. J. H. Slack, whose post-office is Bethlehem, Hunterdon County, New Jersey. 42 AMERICAN FISH CULTURE. CHAPTER in. TROUT BREEDING. IN'CUBATIOX. AND TREATMENT OF FRY. Hatching apparatus. French and American plans. Supply of water for a given number of eggs. Hatching-house. Illustration with explanations. Filterer. Troughs. Nursery. Management of h'lterer. "Washing gravel for troughs. Implements. Taking the spawn. Action of the female when about to spawn. Method of catching the fish on the spawning-beds. Indications of the maturity of the eggs. Manipulation. Placing the ova in the troughs. Packing and transportation of eggs. Manner of taking a large number of eggs for transportation from a trough. How to examine them. Illustration with explanations of the appearance of ova at different stages during incubation. Table showing progress of incubation with water at different degrees of temperature. Hatching out and progress in growth and activity of fry. Treatment of fry. Their food, and manner of feeding them. Their disposition to escape. Transferring them to the nurseries. Their admission into the first pond. Transportation of fry. Hatching Apparatus. Since the early experiments of Reniy, a great many improvements have been made in hatching fish spawn. At Huningue, trays or troughs of earthenware about twenty-five inches long, five inches wide, and four inches deep, are used. The eggs are placed on a grille, made by arranging small parallel cross-bars in a wooden frame, which rests -on projections on each side of the tray, a little below the surface of the water. The- bars TROUT BREEDING. 43 of the grille are near enough together to hold the eggs ; while any floating dirt falls hetween to the bottom of the tray, and can be removed by drawing the water off through a hole which is kept corked at one end in the bottom. The young fish, as they are hatched out, also drop between the bars, and are removed through the same aperture and placed in other troughs or apartments. These trays can even be scrubbed and replaced, by moving the grille (which may safely be done after the young fish are developed in the ova), to a spare tray kept for the purpose. The trays are placed in shallow vessels or cisterns, elevated to the height of a man's waist ; each cistern, which is thirty or forty feet long, containing a proportionate number of trays. It is not deemed advisable, however, that a jet of water from the supply pipes should flow through more than six trays. Another mode in France, is to have a series of troughs arranged like steps, one slightly above the other, as shown in illustration at end of next chapter. The water pour- ing through a hole in a little jet at one end of the upper trough, and running the length of that below, discharges in the same way, and runs the length of the next trough. This plan has the advantage of aerating the water as it enters each, and can be placed in any spare room of proper temperature in one's dwelling. In this country a much more simple, though not as effec- tual, mode of getting rid of sediment and suppressing the A growth of byssus is pursued. wooden trough, twelve or fifteen inches wide, and four inches deep, is divided into 44 AMERICAN FISH CULTURE. nests or apartments from sixteen to eighteen inches long, by placing strips across; over these strips the water flows in a slight ripple, and the force of the current is thereby broken. The bottom of the trough is covered with clean gravel, to the depth of an inch or so, to receive the eggs, over which the water, an inch deep, flows in a gentle current. This plan has generally been discarded in France, but here, by using pure spring water after passing it through three or four flannel screens and a small heap of fine gravel, it is perhaps as efficacious as the French mode. Our largest fish culturist, Seth Green, has by these simple means hatched out ninety per cent., and Stephen H. Ainsworth as high as ninety-eight per cent, of the ova. In my first experiment, which was with filtered Schuylkill water, a thousand eggs produced nearly seven hundred fish. A floating box for hatching is also used. It is made of boards generally a half inch thick ; the bottom is covered with fine wire gauze, which should be painted ; on this the eggs are distributed. If the box does not set deep enough to allow the water to cover the eggs an inch or an inch and a half, sufficient weight should be placed on the cover to sink it to that depth. If the bottom of the box is made of boards and gravel strewed over it, two or three rows of large gimlet holes should be bored in each end below the water line. These boxes are usually two feet long, eighteen inches wide, and about six inches deep, and are tied to a strip extending across the raceway and allowed to float in the current. A box of this kind can also be placed in a spring, its size corresponding with the area. By this mode TROUT BREEDING. 45 of hatching, the advantage of filtration must be dispensed with. The first essay of P. H. Christie in hatching, was by depositing the eggs on gravel in the bottom of a cornpopper, and placing it on a stone in his spring. I mention this to show how simple a thing the hatching of trout spawn can be made. Many persons in France and England, for amusement, or the novelty of the thing, have miniature hatching appara- tus in their houses. Any spare room where the thermometer does not mark over 55 will answer, and the smallest dribble from a tank of twenty to a hundred gallons can be used. No class of our countrymen are more favorably situated for hatching trout spawn than farmers. Many of them bring the water into their houses from springs of greater elevation ; and, without occupying much space, and by incurring but slight expense, might hatch thousands of ova to stock streams and ponds on their own premises, or to supply waters in their neighborhood. I have already remarked, that success in hatchin. de- pends much on the purity of the water, and even the purest must be filtered. As to the quantity for a given number of eggs ; a square inch divided into four jets and flowing through the same number of troughs, will suffice for three or four hundred thousand but double or even ; four times the supply will be required to sustain the same number of young fish for any great length of time in the nursery. An additional supply must therefore be provided for the fry after they have absorbed the umbilical sac, bay a square inch to each hundred thousand. 46 AMERICAN FISH CULTURE. It is better for many reasons, that the supply should flow through earthen pipes or glazed tile ; there is some risk in conducting it through leaden pipe, as the action of certain limestone waters on lead is injurious, unless the pipe is coated with zinc. Although a trough for hatching a few thousand eggs may be placed in the open air if kept covered, it is neces- sary that a number of them should be under the cover of a building of some kind, that the ova may be protected from the weather and the depredations of rats and other animals that would eat them, as well as for the comfort of those A who attend to them. house of rough boards will answer A the purpose. stove is not necessary in the hatching- house unless the water is very cold. Where the water is as high as 48 or 50 the temperature of the air inside of a close board house will be almost the same, and comfort- ably warm. The windows, or the greater number of them, should be on the north side, if it can be so arranged, so as to admit the light with as little sunshine as possible. In a length of forty-eight feet, three windows are enough, the panes may be eight by ten inches, and the sash two panes high and four panes wide, and may slide horizontally in opening them. Each window should have a curtain or sliding shutter to exclude the light when it is deemed expedient to do so. On the opposite page is a ground plan for a hatching house. Scale, one-sixteenth of an inch to the foot. AN is the filterer, four feet long, two feet wide, and eighteen inches deep. The three transverse lines repre- TROUT BREEDING. 47 n [THJ "BT" ILL WII n E 48 AMERICAN FISH CULTURE. sent the flannel screens if there were four it would be ; better. The water entering the first apartment on the right, passes through the screens and flows into the distributing trough B, which by four jets supplies the troughs c c c c. The troughs are thirty-two feet long, fourteen inches wide, and four inches deep, inside measurement. Each trough is divided into twenty nests eighteen inches long, besides having an apartment two feet long at the upper end, which is filled with fine gravel, through which the F water is again filtered as it passes into each trough. is a gravelled walk two feet wide. There should also be a grav- elled space of the same width between the troughs and the sides of the building. D D are the nurseries, three feet wide, and half the length of the hatching-troughs. The lines which extend alternately from each side beyond to the middle, represent small bulkheads or strips, so placed for the purpose of breaking the force of the current when an additional supply of water is let in for the young fish, and to form eddies where they find shelter from its force if they require it. The latter is an improvement of the Rev. Livingston Stone, of Charleston, New Hampshire, and was suggested for this book by Theodore Lyman, Esq., one of the Massachusetts Commissioners of Fisheries. The bottoms of the nurseries should be of boards, and should be gravelled. The depth should not be much, if any, over an inch at the upper end, E and four inches at the lower end. is a channel leading from the nurseries into the first pond. TROUT BREEDING. 49 These four troughs will hatch from three to four hundred thousand eggs. By increasing the supply of water and lengthening the distributing trough, two or even four additional hatching-troughs can be used. The screens of the filterer are made by stretching and tacking flannel to frames, which are slipped into grooves made by nailing strips on the insides of the filterer, either perpendicularly or at an angle inclining towards the outlet. The flannel on the screen nearest the entrance of the supply, should be of stout but open fabric ; the second, nofc so coarse; the third, medium, and the fourth, closely A woven. duplicate set should be provided, as the purest water, to all appearances, in which one cannot detect the most minute particle, will, in the course of four or five days or a week, so clog the screens as almost to stop the flow. At intervals of a few days the screens should therefore be slipped out and a clean set put in. The flannel is cleansed by allowing it to dry, and then brushing the dust off with a whisk broom, or better, by rubbing the screens with a stiff hair-brush while wet. The filterer and supply trough should both be kept covered. There should not be more than two inches fall from the upper to the lower end of a trough of thirty-two feet, if the aperture through which the water enters is a half inch square. If the supply be doubled, the fall should not be more than an inch. This will give a ripple about the six- teenth of an inch deep over the strips dividing the trough into nests. The bottom of the trough should be perfectly true, and the strips fit neatly, so that the water may not 5 D 50 AMERICAN FISH CULTURE. flow beneath but over the top of the strips. The strips should also be exactly the same width, so that the ripples over them may be uniform. They should be made of halfinch pine, and should slip out or in so that they can be removed at one's option. The gravel should be about the size of peas, and if possible of some uniformly dark tint, that the eggs lying on it may be the more easily examined It should be thoroughly washed, by shaking and turning it in a basket in clear running water, and again, by stirring it after placing it in the hatching-trough, commencing at the upper end of the trough and stirring it in each successive nest until the water runs clear. Mr. Ainsworth is so careful as to boil the gravel, that he may destroy the eggs or larvae of insects that may possibly remain after the gravel is merely washed. When there is sufficient fall from the spring to admit of it, it is better to have the hatching-troughs elevated about three feet, so as to allow of an easier examination of the eggs, as it is no small labor to attend to them on the ground if one has four troughs to go over daily during the incubation. A few simple instruments are required by the fish cul- turist. For examining the eggs a small vial, two or three inches long and a half-inch in diameter, is used. The eggs are taken up with a small pair of pliers and dropped into the vial nearly filled with water, which, after replacing the cork, is held horizontally before the light and turned so as to present different views of the eggs. The pliers can be made either of single or double wire; if of the latter, a small bowl can be formed at the end of each prong by bending TROUT BREEDING. 51 My the wire into the required shape for clasping the egg. friend Christie, of Dutchess county, New York, with a little instrument made by bending a thin brass wire into the shape of a miniature spoon and lashing it to a small wooden handle, removes the addled ova from his troughs, he says, three times as fast as he can with pliers. For dipping up young fish in the troughs, a small net is made by D bending a stout piece of wire into the shape of the letter for the frame, the ends of the wire being twisted together on the convex side for the handle. The material used is bobinett, or some light fabric sufficiently open. The net need not be larger than an ordinary tea cup, and is used by moving the straight side along the bottom of the trough. Taking the Spawn. In autumn when the fish work up towards the heads of the ponds, and some of them enter the raceways, it is time that the latter should be covered with loose boards, and that persons should show themselves as little as possible to the fish in that vicinity ; they can be observed through the cracks between the boards. It will be seen that the females only prepare the nests. This is done by laying their sides against the bottom and rapidly flapping their tails to displace the gravel, the males in the mean while being engaged in a defensive war with rivals and fish that are ready at hand to devour the spawn. The peculiar motion of the female when she is about to spawn, or has commenced, is a long, slow, sideway undulation of the body from head to tail, resembling the moving of a snake along the ground, although she does not pro- gress, her vent being down in the excavation she has 52 AMERICAN FISH CULTURE. made, and her abdomen pressed on the gravel to help the emission of the ova. When this is observed it is certain that the trout have commenced spawning. The lower grating or wire screen should then be slipped into its place at the end of the raceway, and the box or trap which I have already described should be covered with a platform made for that purpose. The boards covering the raceway nearest the trap should then be removed, when the fish will run down and find cover under the platform; the upper screen is then quietly slipped into its place and the fish enclosed. On removing the platform the fish are dipped out with a net made of gunny cloth or sea grass skirting, attached to a square frame, which should be as wide as the trap ; it should also be tied at the bottom, so that the string can be removed and the fish dropped into a tub of water. As the fish are manipulated they are returned to the pond or placed in another tub, which is to be emptied into the pond after A the spawn and milt are expressed. milk pan of the ordinary shape, holding about six quarts, and filled a fourth or a third full of clear water, is. also provided for the spawn and milt. It is better that the water should be fecundated first, so that the eggs may be brought into contact with the atoms of milt as soon as they are expressed. The manipulation should be quickly and carefully performed. Putting the hand into the tub and approaching a male, close on him gently and lift him out ; then grasping him with as little violence as possible, with the right hand by the head and shoulders, his head towards the wrist and the left hand TROUT BREEDING. 53 holding the tail, as represented in the figure in the front of this book hold the vent of the fish beneath the ; surface of the water in the pan, bending the head and tail slightly upwards. If the milt is well matured,, and he does not struggle or hold it back, a small portion will be emitted; then with the forefinger of the right hand, the other three still encircling the head and shoulders, rub the abdomen gently towards the vent, extracting all the milt he will give, and stir the water with his tail. If the fish are passive, as they generally are during the operation, the hold on the head and shoulders may be relaxed, and the right hand passed along the body below the head, pressing the milt or the ova towards the vent. The female is handled in the same manner, the eggs flowing in a pale yellow stream from the vent; if she is fully ripe all the eggs should be taken from her; if she is large and struggles, and the same remark applies of course to the males, an assistant should hold the tail. The mere bending of the head and tail, as illustrated, will frequently cause the eggs to flow if the fish is fully ripe. The indications of ripeness when taken in the hand are, firstly, a pale sickly yellow tinge; secondly, she is very soft and flabby; thirdly, the vent is exceedingly protuberant and of a dark purple color ; fourthly, the eggs are loose in the ovary, and fall towards the vent when she is held with the head up, and towards the head if held by the tail, and will flow, as I have just remarked, without pressure, by bending the vent well ' down. If the eggs are not ripe enough to be extruded, they will be felt like shot or small peas in the belly. The 54 AMERICAN FISH CULTUKE. water should be stirred gently, now and then, as each fish is operated upon, and the fish (males or females) may be handled as they come to hand. When enough eggs have been taken tiP cover the bottom of the pan, and enough milt to give the water a milky appearance, the pan may be covered and set aside ; the water of the pond surrounding it, if the weather is cold, or it may be placed in an unoc- cupied nest of one of the hatching-troughs. The eggs, in a few minutes after receiving the milt, will adhere to the bottom of the pan, and should not be disturbed until they are loose, which will be in the course of fifteen or thirty minutes. During this time impregnation takes place, and * About the middle of May, this year, I met Mr. Ainsworth by appointment in Elk county, Pa., to enjoy a few days fly-fishing. In our conversation on the impregnation of ova, he narrated the following occurrence. Last fall, near the end of the spawning season, when the males had mostly cast their milt, he one day had taken enough eggs to cover the bottom of the pan, and could only procure a single male. From this he expressed not more than a good sized drop of milt, not enough to tinge the water. He, never- theless, set the pan away, giving the ova and this slightly sperm- atized water the usual time, and then placed the eggs in a separate nest in his hatching-trough, and was agreeably surprised in a few days to find them all impregnated. In due time they hatched, but few eggs being lost in incubation. Will any biologist give us the result of his speculations as to the number of spermatozoa in this drop of milt ? Although we cannot but admire this wonderful pro- my vision of nature, I cannot advise readers to be as trustful of a single drop of milt imparting its fecundating quality to two or three quarts of water, unless it be for mere experiment. TROUT BREEDING. 55 as soon as possible after they should be placed in the hatching-trough. Wheii all the fish in the trap have been handled, it may be set again, and the boards towards the upper part of the raceway removed. Fish that are not disposed to leave the race should be driven down, and in doing so, although a pole or stick may be used, it is better not to disturb the bottom of the race ; as it is possible that very rough usage may deter them from entering again, and induce them to seek a spawning-place in the pond, where the eggs or the young fry at all events would be devoured. The disposi- tion with the breeding fish to enter the race again, how- ever, is very strong. I have seen scores of them that had been handled and not quite ripe, -on being returned to the pond, waiting for the grating to be removed, and would run up as soon as it was lifted. If there are many ripe fish running up the race, they may be taken and manipulated once or twice a day. When there are fewer spawners, it may be as well to take them only on alternate days. After the eggs have remained in the fecundated water for twenty minutes or a half hour, or until they are loose from the bottom of the pan, they should be washed ; a board extending across the race, or the platform of the trap being a convenient place for doing so. The edge of the pan should be lowered gently beneath the surface that the fresh water may enter. It is then poured off, allowing enough to remain to keep the eggs well covered. After repeating this several times, until the water is clear, the 56 AMERICAN FISH CULTURE. eggs are ready to be placed in the hatching-trough. Although they will be whirled about by the influx of the water in washing, they are so much heavier, that they will remain at the bottom of the pan. The washing should be done with an effort to give them no more motion than is required in the operation. There are sometimes four or five times as many males as there are spawners taken in the trap, particularly at the An first of the season. additional tub should therefore be provided, and the excess of males placed in it for the time, so that their milt may be used or not, as may be required. The plan pursued in France of holding the fish pendent by the head, as is illustrated in the lower figure in the frontispiece, and allowing the spawn to fall into the pan of water below, is not practised in this country by experienced fish culturists. By the improved method of holding the vent beneath the water, the unnatural falling of the eggs from a height, and bringing them in contact with the air before they are impregnated, is avoided. It is obvious also that the new mode is more in accordance with the natural way of the parent fish. Before depositing the eggs in the trough, an extra strip an inch and a half, or two inches wide, if a notch is cut out of the upper side, is placed above the strip at the lower end of the nest, to dam the water and increase the depth. The edge of the pan is then gently lowered beneath the surface that some of the water of the trough may enter, and the eggs poured slowly out, distributing them as evenly as possi- A ble over the nest. more eq"ual distribution should after- TROUT BREEDING. 57 wards be made by using the soft side of a stout feather. A nest fourteen inches wide and eighteen inches long, will suffice for four thousand eggs without their lying on top of each other. When the strip used for the temporary damming of the water is removed, it should be done gradually, that the eggs may not be disturbed, as they would be if it was lifted suddenly. The eggs first placed in a trough, should be in the lower nest, and then in each successive nest towards the head, so that the fry below, hatching out before those above, can have access to the nursery, when old enough, without passing over and disturbing the un- hatched ova, or the young fish that have not absorbed the umbilical sac. A trout, the second autumn, when twenty-one or twenty- two months old, will give from two hundred to three hun- dred eggs. The third autumn, from four to six hundred. The fourth, from a thousand to twelve hundred. The fifth, from two to three thousand, according to its size. The fish culturist will not be able to procure all the eggs A that his spawners have, for his hatch ing-troughs. good portion of the ova will be deposited at night, or between the times of driving them into the trap. Much of it will be devoured as soon as it is emitted, or will be thrown out by repeated nest-making on the same bed of gravel, and then eaten by the fish. Notwithstanding all this, he will find through the winter a goodly number of young fish in his raceway and at the heads of his ponds, that have come from eggs which have escaped these dangers. It would, therefore, be as well to exclude the fish from the raceways 58 AMERICAN FISH CULTURE. at the close of the spawning-season, and prevent the fry that may be hatched out from coming down into the ponds. This can be done by putting in a fine wire screen at the lower end of the trap, and a coarse one to catch the leaves and drift at the upper end. The race will thus be turned into an out-door nursery, and the young fish can be taken at the trap and turned into the first pond, when those from Wie nursery under roof are transferred. Packing and transporting ova. As soon as the first formation of the young fish can be seen, eggs may be sent off, although some persons think that the eyes should be plainly visible before transportation. The plan now pursued at Huningue, is to pack them in short wide-mouthed glass jars. In this country shallow tin boxes are generally used. Both here and in France they are packed in damp moss, the top and bottom of the jar or box being perforated so as to admit some air. The bottom of the box is covered with moss, well washed and water pressed out, but still quite moist ; on this the eggs are spread so as not to overlie each A other. layer of moss an inch thick is then placed on the eggs. Then comes another layer of eggs, and so on until three or four alternate layers fill the box. The tin boxes are securely closed and packed with saw-dust between, in a wooden box, a layer of saw-dust two or three inches thick protecting the top, bottom, and sides, from exposure to A extremes of heat or cold. tin box six inches in diameter and three inches deep will, with the moss, contain easily three thousand eggs. At a temperature from five to fifteen degrees above freezing point, a box of ova, if care- TROUT BREEDING. 59 fully handled, may be two weeks on the way without injury. Seth Green, to test their vitality, has kept eggs packed in moss, in his hatching-house, for more than six weeks, and then placed them in his troughs, where, in due course of time, they hatched out. P. H. Christie, of Dutchess county, New York, sent me last fall in an old tin tobacco box as large as my three fingers, one hundred and twenty eggs by mail ; which from delay by snow-storm and otherwise, were a week on the way. On opening them they were all in A good condition but one, which had been mashed. few thousand eggs, if on the way but two or three days, of course require less exterior protection after packing them in moss than I have recommended above. If the moss becomes dry, the eggs will undoubtedly perish. In manipulating fish by the side of the stream, if at a distance from the troughs, the ova is necessarily carried in water. Care should, therefore, be had that the vessel is perfectly clean and free from any taint or odor that might affect the eggs. Mr. Ainsworth informed me that he once lost two or three thousand by carrying them in a new cedar bucket, and Mr. Robinson, of Meredith Village, New Hampshire, had many thousand lake trout ova spoiled from the jolting they received in a rough wagon. On arrival at its place of destination, the box containing ova should be carefully unpacked, the tin boxes or jars taken out and set in the water of the hatching-house, or in a cool cellar where they will not freeze. Each box or jar, after removing the cover and taking off the top layer of moss, should be immersed in a vessel of clear water and turned 60 AMERICAN FISH CULTURE. bottom up. The moss should then be gently shaken and picked out that the eggs may fall to the bottom ; whatever moss cannot be conveniently picked out with the fingers can be floated and poured off by two or three washings, as is done after taking the eggs from a trout, and before depositing them in the trough. Mr. Ainsworth says : " The best contrivance for taking the eggs from the trough in numbers, is a piece of fine wire cloth six or seven inches square, turned up at the sides and at one end like a dust-pan. In using it, place it on the bottom of the nest and gently brush the eggs into the open end with a feather or wing, then put the wire pan into a dish of water and allow them to slide off. In this manner they can be removed with ease and rapidity. The best thing to examine a large number of eggs on, and see at once all the imperfect and unimpregnated spawn, is a pane of window glass with a tight wooden frame around it. Set this with a half inch of water on it, in the light of a window, shading the side towards the window, so as to allow the light to come up through the bottom of the pane, and you can see every imperfect egg and pick them out. In counting them, a four-sided tin dish with sloping sides, holding forty in a line lengthwise and twenty-five across, can be used. Six eggs laid in a line measure a little over or under an inch. If, therefore, the bottom of the vessel used for counting is six and two-third inches long, by four and one-sixth inches wide, it will take about a thousand eggs to cover it. TROUT BREEDING. 61 123 7 S H 9 20 12 The plate above, was drawn for this book, by my esteemed friend Ainsworth, to whom I have so often alluded. The following explanations of the different figures are his own words. " In a few hours after the spawn is taken, there is a small light brown spot to be seen on the top of the egg whether it is impregnated or not. Turn the egg over any way, in many ways, and as often as you please, this speck will soon rise to the top. This is the germ where impreg- nation takes place. Whether it is between the twq membranes of the ova,* or under the inner membrane, I am not able to say ; but it is certain it revolves within the outer membrane to the top. This speck, when the egg is held before the light in a small vial, looks to be about the size of the head of a small pin elongated upwards, as shown in * There are two membranes to the eggs of fishes, or at least to those whose young come forth with an umbilical sac. That part contained within the inner membrane, it may be said, is somewhat analogous to the yolk in the egg of a fowl, and is the umbilical sac when the fish is hatched out. Hence, it is asserted by some, that the young fish emerges from the egg with the yolk attached. 6 62 AMERICAN FISH CULTURE. figure 1. Looking down on the egg, the speck is seen in the centre, apparently on top, as in figure 2. " Seven days after the ova is taken, (the water at 47), a small circle is seen around the speck, whether the egg be impregnated or not, and the two are so much alike at this stage, that it is difficult to know which are the fecundated, and which are not, and yet a very close examination will show a difference. The fecundated egg has a clearer speck in the centre, and the ring around the speck is larger, as will be seen by referring to figure 3. The unimpreguated is illustrated by figure 4. ' When nine days old, the circle in the impregnated egg has enlarged, a slight brownish or bluish gray tinge per- vading the interior; the germ having spread over a sixth part of the egg, presenting the appearance of figure 5 ; while the unimpregnated still remains as pictured in figure 4. The latter never change after the ninth day, unless to become opaque, which they continue to do during the in- cubation of the fecundated ova, and are as easily distin- guished from them in the hatching-troughs as a few white beads would be if scattered amongst those of transparent glass. " On the eleventh day, the first formation of the fish can be seen ; a brown line extending from the circumference towards the centre of the circle, which now covers one- third of the egg. The appearance of the egg at this time is exhibited, up by figure 6, and sideways by figure 7. " When twelve days old the circle will be seen to cover one-half of the egg. Front view shown by figure 8, side view by figure 9. TROUT BREEDING. 63 " On the thirteenth day the circle has passed three- fourths round the egg, a side view being represented by figure 10. "On the fourteenth day the circle has passed entirely over the egg and the young trout is formed, as shown in figure 11. " On the twenty-fifth day, the eyes, heart, arteries, red blood, circulation of blood and motion will be observed. The egg and young fish at this stage is pictured in figure 12. About the fiftieth day the young trout will begin to come out of the shell, and continue to do so for some days or a week." I have some notes and memoranda of my own on incuba- tion, but the foregoing is so brief, and yet so comprehensive, that I have preferred giving it. In referring to the little plate of figures, Mr. Ainsworth, in a recent letter, says : " It would have been a great advantage to me in the beginning of my experiments, and I hope it will be of much benefit to those who attempt the artificial propagation of trout, as they will see at a glance what has taken me nine years to learn." Mr. Ainsworth has also arranged the following table, giving the temperature of the water from 87 to 54, show- ing the progress of development, the time of incubation, and at what time the young fish will commence feeding. This table is made from memoranda he has kept of all the spawn he has taken for four years ; he says : "I have estimated a little in the higher and lower figures as to the time of hatching, as my water did not hold at these degrees long enough to hatch the ova." AMERICAN FISH CULTURE. Average temperature of water. TROUT BREEDING. ' 65 precaution should be taken to exclude vermin from the hatching-house, the light should be modified with shutters or curtains to the windows, an< the sunshine which pro- motes the growth of byssus, should not be allowed to fall on the eggs. Byssus, which is a fungous growth, is perhaps the greatest enemy ; with its long filaments it closes upon and destroys the vitality of the egg; when one is destroyed the dead egg promotes its growth for the destruction of others, until a score may be clasped by its long fingers. The eggs should be disturbed as little as possible during incubation. An accumulation of sediment in one place can be removed by a glass syphon or syringe to some extent, but no dependence should be placed on such remedies, as the perfect filtration of the water is the main reliance. There are few things more interesting than the observa- tion of the gradual development of embryo and life in the egg of a trout. When the time of its deliverance ap- A proaches, the young fish is restive in its little prison. gleam of sunshine, or the warmth imparted by the hand to the vial containing the ova when examining it, incites it to vigorous struggles for liberty. At last the shell is broken, the head appears, then the pectoral fins, then the tail ; it comes forth and its house floats away. Although helpless, it is