PROGRESS IN BIOLOGICAL INQUIRIES, 1931 513 



or no injuiT to tlie oj'ster tissues. The method may be of further 

 vaUie from a sanitar}^ standpoint, as the medium employed iniiibits 

 the irrowth of spoihige organisms and leaves the meats in better 

 condition for shii)ment. 



In removing; the meats by this method the oyster nuiscle is " put 

 to sleep " or narcotized. Relaxation of the muscle occurs, and the 

 A-alves of the shell are autonuitically pulled apart by the pressure of 

 the hin<::e so that an oyster knife can be easily inserted and the mus- 

 cle severed from the shell with less injury to the meat than by present 

 methods. The narcotization of oysters is accomplished by the use 

 of a small amount of certain mineral and organic acids in combina- 

 tion, which in experimental procedure costs less than 10 cents per 

 thousand oysters. Oysters may be completely narcotized or caused 

 to gape within a period of six hours, and can be kept without injury 

 in this condition for a considerable length of time. In the experi- 

 ments conducted thus far the number of completely narcotized oysters 

 in each lot treated has varied from 60 to 90 per cent. In this con- 

 nection the type and concentration of the chemicals employed are 

 important and further studies are in progress to improve the tech- 

 nique of administering the reagents and test the method on a small 

 commercial scale. 



An important feature of this process is that it is not injurious to 

 the oysters, as they fully recover when returned to fresh sea water 

 and may be treated several times in this manner without deleterious 

 effects. The chemicals employed do not cause shrinkage or volume 

 losses of the meat nor impair their food and market value. Narcosis 

 is obtained by using higher concentrations of chemical substances 

 which normally occur in the body and environment of the oyster. 

 Various inorganic and organic reagents are being tested from a prac- 

 tical standpoint to determine their relative efficiency and value for 

 opening oysters. Those in use at present appear to largely disinfect 

 the oyster meats in the process of opening and keep them fresh, firm, 

 and in excellent condition, free from decomposition, for a long period 

 after treatment. The bacteriological phases of the narcotization 

 process will be studied in greater detail later in respect to the j^urifi- 

 cation of oysters both shucked and in the shell. It appears likely 

 that the principles employed in opening oysters by chemical means 

 can likewise be used to improve the keeping qualities of oyster meats 

 in shipment. In the southern climate particularly such improvement 

 is needed and will greatly aid the marketing of oysters and develop- 

 ment of the industry. 



Oyster investigations in North Carolina. — During the past summer 

 a general survey has been made of the oyster-producing areas in the 

 vicinity of the United States Fisheries Laboratory at Beaufort, N. C, 

 in order to determine the most suitable methods for the development 

 of oyster culture in this region. Experiments and chemical studies 

 dealing with the setting of oysters and the collection of seed have 

 been made in cooperation with Capt. John A. Nelson, State fishery 

 commissioner. 



Various types of collectors for gathering seed oysters have been 

 tested on experimental grounds in Core Creek, Newport River, Oyster 

 Creek, and at the United States Fisheries station at Beaufort. In 

 Core Creek a very good crop of seed oysters was obtained on cement- 



