FISH CROW FISH CULTURE 217 the United States soldiers imprisoned at Rich- mond and elsewhere, " to relieve their neces- sities and provide for their comfort." The confederate government declined to admit the commissioners within their lines, but intima- ted a readiness to negotiate for a general ex- change of prisoners. The result was an agree- ment for an equal exchange, which was car- ried out substantially to the end of the war. In March, f869, Mr. Fish was appointed by President Grant secretary of state, and was reappointed by him at the commencement of his second term in March, 1873. On Feb. 9, 1871, the president appointed him one of the commissioners on the part of the United States to negotiate the treaty of Washington, which was signed by him on May 8 of that year. In November, 1873, he negotiated with Admiral Polo, Spanish minister at Washington, the set- tlement of the Virginius question. FISH CROW. See CEOW. FISH CULTURE, or Pisciculture, the breeding and rearing of fish. The subject may be di- vided into two branches: 1, the rearing and fattening of fish in artificial ponds or lagoons ; 2, the propagation of fish by the artificial im- pregnation of the spawn, which is the signifi- cation ordinarily attached to the term at the present time. Among the Chinese, from the earliest times of which we have knowledge, spawn naturally fecundated, chiefly of the carp family, which abound in China, and the ova of which are attached to various objects, has been an article of traffic. This is procured by pla- cing fagots upon frames permanently fixed in localities where the fish are accustomed to deposit their eggs. The fagots when covered with spawn are collected, and the ova are hatched in artificial ponds, canals, or submerged rice fields. Earthen jars are also said to be used, in which the spawn is placed and shaded by a peculiar weed, which also furnishes food for the young fry. In certain rivers the newly hatched fry are taken from the cavities in their beds by divers in small nets with fine meshes, and are preserved in copper vessels for several days by frequent changes of water and supplies of food from the pulverized yolks of hard-boiled eggs, until placed in the waters they are in- tended to stock. By these means fish are ren- dered abundant and cheap. Roman epicures bred fish for their tables. Lucullus had fish ponds at Tusculum, which were connected by canals with the sea, and fed by streams of fresh water. Sea fish, that breed in fresh wa- ter, passing through the canals, stocked the ponds with their young, but were prevented by flood gates from returning to the sea. Ser- gius Orata introduced the culture of oysters in the Lucrine lake. In former times carp were reared for the market in immense ponds in Prussia, Saxony, Bohemia, Mecklenburg, and Holstein. In Italy the culture of the eel is carried on extensively in the lagoons of Venice, at Comacchio, and elsewhere, in connection generally with other species, such as mullet and plaice. This industry at Comacchio is as old as the 13th century. The lagoon at this place is situated between the Reno and Volano branches of the Po, and is divided into numerous sections, the principal entrances into which are from the two mouths. Its waters are diked out from the Adriatic, which however communicates with the lagoon through the Grand Palotta canal and its branches. Flood gates control the various entrances and regu- late the migration of the fish. The ascent of the young eels from the sea commences in the beginning of February, and continues until the end of April, when the flood gates are closed. The harvest commences early in Au- gust, and continues till December. During the interval from their ascent until the close of the season the fish are carefully fed. At Bizerta, in Tunis, a small stream running into the sea has been widened just above the town into a shallow pond of 60 to 100 acres. The water is at no time much above the level of the sea, which occasionally flows back into the pond. The greater portion of the area is di- vided into 12 compartments by a cane fence, which separates the fish, but does not prevent the circulation of the water. Each compart- ment is said to contain a different kind of fish. The pond is under municipal control, and offi- cers are appointed to manage it. The fish are said to be taken for an entire month from the same compartment, which is left undisturbed for the next 11 months. The profit to the town amounts to $12,000 or $15,000 a year. Oyster culture is carried on extensively in France. This bivalve is propagated by " spat," which, ejected like mist from the parent oyster, at first rises to the surface, and subsequently sink- ing is carried by wind and tide until it finds some object to which to attach itself. To ar- rest the drifting spat, which is the chief object in oyster culture, walls of stone or turf, hurdles of brush, fagots, and lines or enclosures of posts are used ; and in more quiet waters ma- ture oysters and oyster shells are laid for the young to attach themselves to. This method has been adopted to replenish the old oyster beds in the bay of St. Brieuc and at the isle of Re ; and in the island of Jersey and at many places along the English coast resort has been had to the same process. In Lake Fusaro, Italy, where oyster culture has been carried on since the Roman period, the oysters are laid down on mounds of stone, and the spat is arrested by enclosures of posts, as well as by fagots suspended from chains and ropes. In the United States the industry has proceeded no further than the depositing of the oyster in eligible localities for growth. Chesapeake bay is the chief locality from which oysters are ob- tained. The best planting grounds are in Tan- gier sound, which borders on the counties of Dorchester and Somerset, Md., and is shut in from the rest of the bay by a series of islands. The quiet of the waters is favorable to the. preservation of the spat, and the abundance of
