EUROPEAN METHODS OF OYSTER-CULTURE. 
403 
3. That the amount of oyster food appears to be notably characteristic of a locality 
whose normal food value is represented by conditions of warmth, density, and richness 
in the organic and inorganic salts, which serve to rapidly generate the oyster-food 
organisms. Should this natural food value of a locality be a high one, culture has 
demonstrated empirically that the number of oysters that may be reared is exceed- 
ingly great. It would appear that the number of oysters to be fattened is directly 
proportioned to the food normal of the locality and to the volume of water which 
passes over the bed. The actual size of a natural oyster bed is limited by other rea- 
sons than that of failure of the food supply in the neighborhood. 
The study of the management of the natural oyster-grounds of Europe has been a 
suggestive one, not as much in regard to attempts made to i-ender them more fertile 
and more serviceable in directly supplying the markets, but in their indirect yet 
important bearing upon the production of seed in neighboring areas. This system of 
stated oyster reserve has been the key to the success achieved by the French and 
Dutch industries, and has alone rendered it possible for these two countries to supply 
the entire seed market of Europe. 
To obtain seed oysters by collectors is shown to be possible only when a regular 
yearly fall of spat is thus assured. Proximity to a large stock of spawning oysters 
is one of the imperative conditions of artificial production, a condition that has been 
too often lost sight of in experiments made along the Atlantic coast of the United 
States. Collectors in Europe are placed on no river bank or sunk in no stream save 
where the culturist is fairly sure of a set that will be at least profitable. 
If experiments in artificial production are to be made in the United States the 
suggestion given by European oyster-culture is to secure for the purpose a particular 
part of beach near the line of low water, where spat has been found to regularly occur. 
If a trial demonstrates that the locality is favorable, the European culturist would 
then gradually and carefully expend his money in the purchase or preparation of a 
more extended area for collecting, and would study to provide the most suitable form 
of collector. 
It may be said, in passing, that experience has found no more economical collector 
than the tile. This has proven especially valuable in adapting itself to the needs 
of the locality, may be spread singly over hard beaches, where there is no danger of 
sediment, and may in muddy regions be arranged in banks or champignons. 
There can be no doubt that artificial production would succeed in American 
waters. The question is the practical one, whether it would, on an extended scale, be 
less costly than the price of natural seed. This can only be determined by experiments 
in a favorable locality. 
Artificial production, it will be remembered, is largely carried on near the line of 
low water. Open tidal ponds, utilizing for this purpose a higher zone of the shore, 
have as yet never given the best results. In closed tidal ponds the small water volume 
has never been successfully aerated for the needs of production: the use of a closed 
lake whose large size shall insure aeration naturally may prove permanently success- 
ful and should not be lost sight of.* 
U. S, F. C. Bull., 1890, p. 372. 
