438 



SCIENCE. 



[Vol. VI., No. 145. 



As it is microscopic and only about half as 

 thick as a sheet of thin paper, it may be smothered 

 by a deposit of sediment or mud so light as to be 

 invisible ; and most of the failures to get a good 

 * set of spat ' are due to the formation of a coat of 

 sediment upon the collectors before the young oys- 

 ters come into contact with them. 



It occurred to me this summer that this danger 

 could be entirely avoided by the use of floating 

 collectors ; for little sediment can fall on a body 

 which is close to the surface of the water, and 

 most of this will be swept away by currents, which 

 will, at the same time, sweep the swimming em- 

 bryos down into the collector, and thus insure an 

 early, abundant, and successful ' set.' 



I accordingly constructed a floating car, made 

 so as to permit the free circulation of the water. 

 This was fiUed with clean oyster-shells, and 

 moored in the channel in front of the laboratory 

 at Beaufort, N. C. , on July 4. As aU the oysters 

 in the vicinity were in very shallow water, they 

 were nearly through spawning, and the condi- 

 tions were therefore very unfavorable : but, not- 

 withstanding this, I immediately secured a good 

 ' set,' and the young oysters grew with remarkable 

 rapidity, on account of the abundant supply of 

 food and fresh water which gained ready access 

 to all of them, and the uniform temperature 

 which was secured by the constant change of 

 water. 



This method of oyster culture may be applied 

 in many ways, of which the most obvious is the 

 production of seed oysters for planting. 



The ' seed ' which is used for planting in Mary- 

 land and Virginia, as well as in Delaware and far- 

 ther north, is now procured from the natural beds 

 of our waters by tonging or dredging, and as the 

 demand for oysters for this purpose is certainly 

 one of the elements which have led to the deple- 

 tion of our beds, there is a wide-spread feeling 

 that the exportation of 'seed' should be pro- 

 hibited. 



By a small investment of capital in floating col- 

 lectors, any one on tide-water could easily raise 

 large quantities of much better, cleaner seed than 

 that which is now procured from the natural beds ; 

 and, if the laws permitted the sale and transporta- 

 tion of this seed without restriction at the season 

 when the demand exists, it could be sold at a profit 

 for less than the cost of tonging. 



Northern planters could also raise seed for them- 

 selves by constructing floating collectors in the 

 warm water of the sounds of Virginia and North 

 Carolina, where the length of the summer would 

 permit several collections to be made in one season. 

 The oysters thus reared are large enough for 

 planting in five or six weeks, and in the latitude 



of Beaufort there is an abundance of spat from the 

 middle of April to the first of July, and it can be 

 collected until September. 



The method may also be used by planters for 

 collecting then- own seed, especially in regions re- 

 mote from a natural supply. If there are no oys- 

 ters near to furnish the eggs, a few spawning 

 oysters may be placed among the shells in the col- 

 lector, after the French method, to supply the 

 ' set.' 



It can also be used for the direct production of 

 marketable oysters, especially over muddy bot- 

 toms, and in regions where public sentiment 

 does not permit any private ownership of the 

 bottom. 



As food for the oyster is most abundant at the 

 mouths of muddy creeks, where the bottom is too 

 soft for oyster culture by planting or by sheUing, 

 this method will have especial advantage in such 

 places ; for there will be no danger of sanding or 

 of smothering by mud at the surface, and there 

 is no limit to the number of oysters which can 

 thus be grown on a given area, for the free cur- 

 rent of water will bring food to all of them. 



The very rapid growth will more than compen- 

 sate for the cost of the floats, and Mr. Armstrong's 

 experiment shows that, in addition to all these 

 advantages, the oysters are of a better shape, with 

 better shells, and more marketable, than those 

 grown at the same place on the bottom. 



Finally, this method will do away with the 

 necessity for a title to the bottom, and will thus 

 enable a few enterprising men to set the example 

 of oyster culture, and, by the education of the 

 community, to hasten the time when wiser laws 

 will render our natural advantages available for 

 the benefit of our people. 



The most economical method of constructing 

 floats must, of course, be determined by practical 

 experiments; but a float constructed by connecting 

 two old ship-masts together by string pieces, with 

 a bottom of coarse galvanized iron netting, would 

 have sufiicient buoyancy, and enough resistance 

 to water, to support a large quantity of submerged 

 sheUs and oysters for two or more seasons, and 

 a coating of copper paint each year would protect 

 the timbers from worms. 



The floats should be open at the ends to per- 

 mit free circulation, and they should be moored 

 in such a way as to swing with the current. 



Engagement in business projects is no part of 

 the office of a university, and I feel that the ex- 

 periments of the past summer have brought the 

 subject of oyster culture to a point where its fur- 

 ther development should be left to the people who 

 are most interested. 



W. K. Brooks. 



