PEOGEESS IN BIOLOGICAL INQUIEIES, 19 30 613 



ing this metal are helpful in this respect for a great amount of the 

 metal had a poisonous effect on the larvae and caused death in a very 

 short time. Trade wastes of an alkaline nature are also found to be 

 detrimental as they precipitate from the river water its normal 

 content of copper and thus deprive the oyster of an essential element 

 for setting and transformation into the adult stage. 



Experiments tvith the partition type of seed-oyster collector. — Ex- 

 periments carried out in Connecticut by Mr. Prytherch in cooperation 

 with the Bluepoints Co., Connecticut Oyster Farms Co., and F. 

 Mansfield Oyster Co., have shown conclusively that the cement-coated 

 partition is a practical and efficient device for collecting and trans- 

 planting heavy crops of seed oysters. In Milford Harbor over 

 20,000,000 seed oysters were collected on approximately 5 acres of bot- 

 tom by the 7,000 partitions planted there by Capt. C. E. Wheeler of 

 the Connecticut Oyster Farms Co. On this same acreage the setting 

 was sufficiently heavy to warrant a planting of ten times as many 

 partitions, which would easily have collected 50,000,000 more seed 

 oysters that were lost as a result of overcrowding and lack of room 

 for growth. For example, it was found by actual count that from 

 8,000 to 12,000 spat were attached per single partition on August 20 

 and that by the middle of September this number had been reduced 

 to approximately 4,000 to 6,000 as a result of overcrowding. The 

 shells and gravel over which the partitions were planted were also 

 totally covered with spat so that the partitions actually saved 

 millions of seed which would otherwise have been lost. 



Several of the partitions were weighed when the spat were only 

 a few days old and also when they were 2 months old and ready to be 

 transplanted. During this interval the weight of a single partition 

 increased on the average from 2 to 2^ pounds, which shows that 

 approximately 7 tons of oyster seed were collected and grown on the 

 7,000 partitions. Similar results were obtained by the Bluepoints 

 Co., with a schooner load of 13,000 partitions, which were brought 

 over from Great South Bay, Long Island, and planted in Long Island 

 Sound off Bridgeport. There was no evidence that a set Avould occur 

 in the former region; and since predictions had been issued for a 

 heavy set in Connecticut, it was deemed advisable to move the 

 collectors to the more promising region. On the advice of the bureau 

 the shipment was rushed and planted just in time to catch one of the 

 heaviest sets of oysters that has occurred in Connecticut in recent 

 years. In New Haven Harbor the 5,000 partitions which were 

 jilanted under various conditions by Howard W, Beach of the 

 F. Mansfield Oyster Co. collected approximately 10,000,000 seed 

 oysters in addition to those on the shells over which the partitions 

 were planted. • 



The partitions used during the past summer were greatly improved 

 by making them according to the pattern used in cardboard fillers 

 for duck eggs. With this design the compartments were much larger 

 and deeper and allowed greater room for growth of the oyster spat. 

 Each partition consisted of 12 interlocking strips, lli/o by 2% by 

 31/2 inches, which when coated with a mixture of cement, lime, and 

 sand, presented a total surface of approximately 690 square inches. 

 In coating the partitions, various mixtures were tested, the most 

 suitable being found to consist of the proportions of two sacks of 



