SEA-FISHERIES LABORATOEl. 73 



Fisii Parasites and Fish Diseases. 



Mr. Johnstone has an important article dealing with 

 certain new internal parasites of common fishes in the 

 district, and also with various diseased conditions in the 

 Raj, the Cod and the Flounder, wliicli have been 

 investigated in the Laboratory' during the year. All 

 these points are rather technical and cannot be brietlv 

 summarised, but they all add important items to our 

 knowledge of tlie conditions under Avhich our fish live. 

 A further paper on a similar subject, viz., a diseased 

 condition which affects the spawning Plaice in the 

 hatchery ponds at Port Erin, is given by Mr. W. Riddell 

 and Dr. Alexander, and the Bacteria found in the 

 diseased fish are discussed. 



Bacteriology of Siiell-Fisii Beds. 



The shell-fish (juestion in its relation to Public 

 Health is becoming of increasing importance, almost year 

 by year. Mr. Johnstone, Avho carries out our bacterio- 

 logical investigations, has had further work in connection 

 with the Conway Mussel beds during the past year, and 

 has just made a report to the Fishery Board iov 

 Scotland on the topographical and bacteriological con- 

 dition of the Oyster beds in the Firth of Forth, near 

 Edinburgh. On account of the growing importance of 

 this work, and the prospects of its increase in the near 

 future, I have thought it useful to give in the present 

 Report a summary and discussion of the bacteriological 

 investigations that have been undertaken in the past 

 under the direction of the Committee, and to point out 

 how necessary it is that the topographical relations of the 

 samples examined in the laboratory should be studied by 

 the naturalist in the field. Tides and other currents, 



