The most suitable bottom for oyster culture consists of firm mud or of a firm substratum with a thin surface of soft until, but stable sandy bottom is often used with success. Rocky bottom is usually deficient in food, loose sand drifts and covers the oysters, and very soft mud ingulfs and stifles them or produces inferior elon gate stock. Mud naturally too soft may be util ized by distributing over it shells, sand. or other material, which, resting on or near the surface, furnishes a firm foundation upon which the growing oyster may repose in security. For spat collecting it is frequently advantageous to use hard mud, gravel, 111' rocky bottom in shoal water, ill adapted to adult oysters from deficiency of food. The bottom being properly prepared and its boundaries marked with stakes or buoys, either system may be adopted to accord with circumstances. Generally seed-planting is more certain in its results and yields quicker returns to the grower. Seed-oysters vary from 'blisters' inch in diameter to individuals almost ready for market, but ordinarily they are between and 3 inches long. They are obtained from planters making a specialty of seed production or from natural beds, their cost varying from 10 cents to $1 per bushel, the larger culled stock, separate, well shaped, and free from rubbish, bringing higher prices and giving the best results. From 300 to 600 bushels of culled seed per acre are used, a larger quantity of 'rough' material be ing required, as much of it consists of old shells and debris. It is usually sowed broadcast with shovels from boats. Further attention, other than that required to keep the beds clean and free from enemies, is generally unnecessary, espe cially if culled seed has been used.
The system of spat-collecting is often extreme ly productive, though sometimes, for reasons not well understood, it results in complete failure. Spat will attach to almost any clean solid body, hut certain materials,from their shape.structure, or cheapness. possess advantages which commend them. The most widely used and one of the best forms of culteh consists of the clean shells of the oyster itself. They are cheap, readily ohtain able in all oyster regions, and, owing to their size and shape, can lie used with success on bot tom too soft for most other moterials. The prin cipal objection to them is that so many spat sometimes attach to a shell that they have no room for growth, and scallop (Pecten), jingle (Anomia), and other small fragile shells are sometimes preferable, as they catch the spat in smaller clusters and tend to break up as the oysters grow. but, owing to their lightness, they cannot be used in strong currents. The cost of oyster shells is from 2 to 5 cents per bushel, and sometimes they may be had for the hauling. Coarse gravel, pebbles, and crushed stone are used to a considerable extent in Long Island Sound and vicinity, but require a harder bottom than shells. The particles average about the size of a walnut or smaller, and as but few spat attach to each, the oysters are well shaped, less laborious to cull, and a larger proportion survive. This material costs from 5 to 8 cents per bushel and the cost of planting is about the same as of shells, to 5 cents per bushel, according to local conditions.
Shells, stones, and gravel are distributed, like seed, from boats or scows. From 250 to 600 bush
els per acre are used, soft bottom requiring more than hard. if there are extensive beds of adult oysters in the vicinity, and especially if the cur rents set from them to the spat-beds, they can be depended upon to supply the fry, but if not, adult oysters should be used in the proportion of 30 to 60 bushels per acre. The brood oysters should be planted several months before the spawning season, but the cultch should not be put down until spawning is about to begin, that it may he free from slime and sediment when the fry is ready to fix, even a thin coating of sedi ment being sufficient to suffocate the young oyster at that period.
Some planters allow the beds to remain un worked until the crop is ready to market, but to produce oysters of superior shape and quality, the clusters should be taken up and separated as soon as they can be culled without injury. It fre quently happens that good localities for obtaining a set are not favorable to the production of mar ketable oysters, and in this case the culled young may be transplanted with advantage and profit to beds possessed of an environment more favor able for the adults. Whether cultch or seed be planted, the beds should be closely watched to protect them from enemies which sometimes work havoc unsuspected until the time comes to market the crop.
The United States Fish Commission is ex perimenting with a system of fattening oysters artificially, by using fertilizers to stimulate the production of oyster food in ponds. Good results have been attained, but the commercial feasi bility of the method has not yet been demon strated. The alleged method of fattening oysters by feeding with corn meal is worthless. 'Plump ing' them by placing in fresh or nearly fresh water is a bloating and not a fattening treatment, and is less resorted to than formerly. Oysters should not be planted or bedded in the vicinity of sewage contamination, as they may thereby become sources of disease infection, hut there is no danger to be anticipated from the consumption of oysters from beds remote from sources of con tamination. Green oysters are sometimes placed on the market. There are three types of green ness, two of which are perfectly harmless. The third type is evidently a pathogenic condition, correlated with the presence of copper; but, while the affected oysters are poor in quality, it is not demonstrated that they are dangerous.
tween the bottoms used for spat-collection and for growing, although ponds are not used. Bam boo branches in regular arrangement are used for spat-collectors and the oysters are usually twice transplanted, first to a place favorable for rapid growth, and finally to beds especially rich in food, where they fatten.
ButtimmxenY. Huxley, Oysters and the Oyster Question (London, 1883) ; Ingersoll, The Ouster Industry ( Washington, 1887); Brooks, The Oyster (Baltimore, 1891) : Dean, Report on the European Methods of Oyster Culture (Washing ton, 1893) ; Moore, Oysters and Methods of Oyster Culture (Washington, 1897) ; lierdinann and Boyce, Oysters and Disease (London, 18991 ; Pottier, Lts huitres comestibles rt Postreicul tare (Paris, 1902). Also the reports of the several State oyster commissions. and especially the United States Fish Commission Reports and Bulletins.