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Rh 128 PISCICULTURE ripe for a general acceptance of its usefulness, a period during which its practice was never abandoned by the Germans. Fish-culture in Britain was inaugurated in 1837 by Mr John Shaw, gamekeeper to the duke of Buccleuch at Drumlanrig, who, in the course of ichthyological investiga tions, had occasion to fecundate the eggs of salmon and rear the young ; and, as regards France, an illiterate fisher man, Joseph Remy, living in the mountains of the Vosges, rediscovered, as it is claimed, or at any rate successfully practised, in association with Antoine Gehin, the culture of trout in 1842. The originality and practical influence of Remy and Gehin s work appear to have been exaggerated by French writers. On the other hand the establishment in 1850 at Huningue (Hiiningen) in Alsace by the French Government of the first fish-breeding station, or &quot;pisci- factory,&quot; as it was named by Professor Coste, is of great significance, since it marks the beginning of public fish- culture. The art discovered in Germany was practised in Italy as early as 1791 by Baufalini, in France in 1820, in Bohemia in 1824, in Great Britain in 1837, in Switzerland in 1842, in Norway under Government patronage in 1850, in Finland in 1852, in the United States in 1853, in Belgium, Holland, and Russia in 1854, in Canada about 1863, in Austria in 1865, in Australasia, by the intro duction of English salmon, in 1862, and in Japan in 1877. Artificial Propagation. Sponges have been successfully multi plied by cuttings, like plants, in Austria and in Florida. Oysters have long been raised in artificial enclosures from spat naturally deposited upon artificial stools. The eggs of the American and Portuguese oysters have been artificially fecundated and the young hatched, and in July 1883 Mr John A. Ryder, embryologist of the U.S. Fish Commission, solved the most difficult problem in American oyster-culture by completing a mechanical device for pre venting the escape of the newly hatched oysters while swimming about prior to fixation. 1 The English oyster, being hermaphrodite, or moncecious, cannot be artificially propagated from the egg like the dioecious American species. The fertilization of the fish egg is the simplest of processes, con sisting, as every one knows, in simply pressing the ripe ova from the female fish into a shallow receptacle and then squeezing out the milt of the male upon them. Formerly a great deal of water was placed in the pan ; now the &quot; dry method, with only a little, discovered by the Russian Vrasski in 1854, is preferred. The eggs having been fertilized, the most difficult part of the task remains, namely, the care of the eggs until they are hatched, and the care of the young until they are able to care for themselves. The apparatus employed is various in principle, to correspond to the physical peculiarities of the eggs. Fish-culturists divide eggs into four classes, viz. : (1) heavy eggs, non-adhesive, whose specific gravity is so great that they will not float, such as the eggs of the salmon and trout ; (2) heavy adhesive eggs, such as those of the herring, smelt, and perch ; (3) semi-buoyant eggs, like those of the shad and whitefish (Coregonus] ; and (4) buoyant eggs, like those of the cod and mackerel. (1) Heavy non-adhesive eggs are placed in thin layers either upon gravel, grilles of glass, or sheets of wire cloth, in receptacles through which a current of water is constantly passing. There are numerous forms of apparatus for eggs of this class, but the most effective are those in which a number of trays of wire cloth, sufficiently deep to carry single layers of eggs, are placed one upon the other in a box or jar into which the water enters from below, passing out at the top. (2) Heavy adhesive eggs are received upon bunches of twigs or frames of glass plates to which they adhere, and which are placed in receptacles through which water is passing. (3) Semi-buoyant eggs, or those whose specific gravity is but slightly greater than that of the water, require altogether different treatment. They are necessarily placed together in large numbers, and to prevent their settling upon the bottom of the receptacle it is necessary to introduce a gentle current from below. For many years these eggs could be hatched only in floating receptacles with wire-cloth bottoms, placed at an angle to the current of the stream in which they were fixed, the motion of which was utilized to keep the eggs in suspension. Later an arrangement of plunging-buckets was invented, cylindrical recep tacles with tops and bottoms of wire cloth, which were suspended in rows from beams worked up and down at the surface of the water by machinery. The eggs in the cylinders were thus kept 1 Bulletin, United States Fish Commission, 1883. constantly in motion. Finally the device now most in favour was perfected ; this is a receptacle, conical, or at least with a constricted termination, placed with its apex downward, through which passes from below a strong current, keeping the eggs constantly suspended and in motion. This form of apparatus, of which the M Donald and Clark hatching-jars are the most perfect development, may be worked in connexion with any common hydrant.- (4) Floating eggs have been hatched only by means of rude contrivances for sustaining a lateral circular eddy of water in the receptacle. The use of refrigerators, to retard the development of the eggs until such time as it is most convenient to take care of the fry, has been extensively introduced in the United States, and has been experimented upon in Germany. The distinction between private and public fish-culture must be carefully observed. The maintenance of ponds for carp, trout, and other domesticated species is an industry to be classed with poultry- raising and bee-keeping, and its interest to the political economist is but slight. The proper function of public fish-culture is the stocking of the public waters with fish in which no individual can claim the right of property. This is being done in the rivers of the United States, with salmon, shad, and alewives, and in the lakes with whitufish. The use of steamships and steam machinery, the construction of refrigerating transportation cars, two of which, with a corps of trained experts, are constantly employed by the United States Fish Commission, moving fish and eggs from Maine to Texas, and from Maryland to California, and the maintenance of permanent hatching stations, seventeen in number, in different parts of the continent, are forms of activity only attainable by Government aid. Equally unattainable by private effort would be the enormous experiments in transplanting and acclimatizing fish in new waters, such as the planting of California!! salmon in the rivers of the east, land-locked salmon and smelt in the lakes and rivers of the interior, and shad in California and the Mississippi valley, and the extensive acclimatization of German carp ; the two last-named experiments carried out within a period of three years have met with successes beyond doubt, aiul are of the greatest importance to the country ; the others have been more or less successful, though their results are not yet fully realized. It has been demonstrated, however, that the great liver fisheries of the United States, which produced in 1880 48,000,000 Ib of alewives, 18,000,000 tt&amp;gt; of shad, 52,000,000 ft&amp;gt; of salmon, besides bass, stur geon, and smelt, and worth &quot; at first hand &quot; between 4,000,000 and 6,000,000 dollars, are entirely under the control of the fish-culturist to sustain or to destroy, and are capable of immense extension. Having now attempted to define the field of modern fish-culture, and to show what it has already accomplished, it remains to be stated what appear to be its legitimate aims and limitations. The aims of modern fish-culture, as understood by the present writer, are (1) to arrive at a thorough knowledge of the life history from beginning to end of every species of economic value, the histories of the animals and plants upon which they feed or upon which their food is nourished, the histories of their enemies and friends, and the friends and foes of their enemies and friends, as well as the currents, temperatures, and other physical phenomena of the waters in relation to migration, reproduction, and growth ; and (2) to apply this knowledge in such a practical manner that every form of fish shall be at least as thoroughly under control as are now the salmon, the shad, the alewife, the carp, and the whitefish. Its limitations are precisely those of scientific agriculture and animal rearing, since, although certain physical conditions may constantly intervene to thwart man s efforts in any given direction, it is quite within the bounds of reasonable expecta tion to be able to understand what these are, and how their efl ects are produced. An important consideration concerning the limita tions of fish-culture must always be kept in mind in weighing the arguments for and against its success, viz., that effort towards the acclimatization of fishes in new waters is not fish-culture, but is simply one of the necessary experiments upon which fish-culture may be based. The introduction of carp from Germany to the United States was not fish-culture ; it was an experiment ; the experiment has succeeded, and fish-culture is now one of its results. The intro duction of California salmon to the Atlantic slope was an experi ment ; it has not succeeded ; its failure has nothing to do with the success of fish-culture. If any one wants to see successful fish- culture in connexion with this fish let him go to the Sacramento river. The introduction of shad to the Pacific coast was an experiment ; it succeeded ; shad culture can now be carried on without fear of failure by the Fish Commission of the Pacific States. An equally established success is whitefish culture in the Great Lakes. The experiments with cod and Spanish mackerel were not fish-culture, though it is hoped that they may yet lead up to it. And there is every reason to believe, from experiments in part completed, that the dominion of fish-culture may be extended in like manner to certain of the great sea fisheries, such as the cod, haddock, herring, mackerel, and Spanish mackerel fisheries. 2 Transactions, American Fish Cultural Association, 1883.