U. S B. F.— Doc. 951. 



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Fig. 1.— E.xperimental oyster hatchery, showing outdoor equipment consisting of one large 

 spawning tank and three rearing tanl^s with filter hlocks in place. 



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Fig. 2.— Artificial spat collectors coated with paraffin and sand, which allows heavy sets to 

 break up into single oysters after one or two months. 



