

SEA-FISHEBIES LABOEATOKY. 159 



the possibility, or even in some cases the probability, of 

 their being the carriers of disease germs. We gave a 

 preliminary account of our work at the meeting of the 

 British Association in Ipswich last September, and we 

 shall prepare a detailed Report upon the matter to be laid 

 before the next meeting of the British Association in 

 Liverpool in September, 1896, but in the meantime so 

 much public interest and apprehension has been raised 

 by several recent outbreaks of typhoid popularly attributed 

 to oysters, and the matter is so closely connected with the 

 shellfish industries of this .district, that I consider it 

 advisable to give a summary here of the results of our 

 w T ork up to the present time. 



A. The objects we had in view in entering on the 

 investigation were as follows : — 



1. To determine the conditions of life and health and 

 growth of the oyster by keeping samples in sea waters of 

 different composition— e.g., it is a matter of discussion 

 amongst practical ostreiculturists as to what specific 

 gravity or salinity of water, and what amount of lime are 

 best for the due proportionate growth of both shell and 

 body. 



2. To determine the effect of feeding oysters on various 

 substances — both natural food, such as Diatoms, and 

 artificial food, such as oatmeal. Here, again, there is a 

 want of agreement at present as to the benefit or other- 

 wise of feeding oysters in captivity. 



3. To determine the effect of adding various impurities 

 to the water in which the oysters are grown, and especially 

 the effect of sewage in various quantities. It is known 

 that oysters are sometimes grown or laid down for 

 fattening purposes in water which is more or less con- 

 taminated by Bewage, but it is still an open question ;is 

 to the resulting effect upon the oyster. 



